Final Report Summary - WI-SHOE (A novel Wireless, wearable Shoe-based system for real time monitoring of Energy Expenditure and Gait parameters for Sport and Medical Applications)
Executive Summary:
Gait parameters monitoring and energetic expenditure calculation is of high importance for patients recovering from diseases that affect movement, such as stroke or for patients in the rehabilitation phase after a surgery. The same applies to professional athletes either (a) in the phase of recovery from a lower limb injury or (b) performing a sport requiring very precise body posture and/or movement control, like baseball or triple jump.
The Wi-Shoe project developed a completely non-intrusive wearable shoe-based system used for measuring kinematic gait parameters and energetic expenditure during various activities. The Wi-Shoe system integrates miniature sensors in a custom designed shoe sole. Different types of shoes can be made based on novel shoe sole designs. During the project, two different shoes were developed; a casual, everyday shoe and a sports shoe. Wi-Shoe answers the actual need of the healthcare, rehabilitation and sport sectors for a person-centric product that will allow continuous monitoring of the subject without the need for an expert’s intervention, promoting the role of “home as care environment”.
Data from the Wi-Shoe are wirelessly sent to a nearby smartphone for evaluation of the subject's condition and gait performance, as well as for real-time warnings generation. Data can also be forwarded to a Professional, cloud-based version of the Wi-Shoe software for full data analysis. The system offers also historical analysis of results.
Wi-Shoe novelty lies on the fact that it is the first time that such an integrated approach for measuring both kinematic gait parameters and energetic expenditure during various activities is presented. Measurements accuracy is also significantly higher, compared to most available market solutions in the same target price range. A lower cost version of the Wi-Shoe has also been developed, for applications that do not require increased precision in the measurements. Furthermore, the use of the Wi-Shoe system is much simpler with respect to all currently available solutions, since for the subject it is just a pair of shoes that he/she needs to wear. The Wi-Shoe does not require frequent calibration and most importantly, it can be used at home or wherever the subject prefers in everyday activities. An easy to use calibration device for the Wi-Shoe has also been prepared. A dedicated application is available for guiding the users through the calibration procedure. In addition, the Wi-Shoe allows remote monitoring of the subjects, without the need for continuous expert intervention. In this way, Wi-Shoe improves and supports the monitored subject’s sense of independence, which is of major psychological importance.
Project Context and Objectives:
The aim of the Wi-Shoe project has been to develop a completely non-intrusive wearable shoe-based system used for measuring kinematic gait parameters and energetic expenditure during various activities. Focus was put on rehabilitation patients and athletes that wish to improve their walking/running efficiency.
The Wi-Shoe system integrates miniature sensors in a custom designed shoe sole. Different types of shoes can be made based on the novel shoe sole designs prepared. During the project, two different shoes were developed, based on existing models offered by the consortium partner Podartis: a casual, everyday shoe and a sports shoe. As a first step in the project, a study was made to identify kinematic gait parameters that need to be monitored for all possible end-user categories. Calculation methods for all parameters have been studied. Preliminary experiments were conducted for understanding the maximum dimensions and weight that a shoe can have for normal walking. This allowed for a maximum preliminary system sizing. An end-user survey was also conducted to identify the most suitable specifications from a user perspective. Survey results were used for the preparation of the technical specifications. Based on these activities, the technical requirements were prepared. These included high level requirements, as well as specific requirements for the main hardware & software components. A preliminary concept drawing of the sole was prepared in order to estimate available space for the electronics.
After this phase, the shoe electronics were prepared, including the data acquisition and transmission module. A preliminary prototype was first developed for testing & integration purposes. Various force measurement technologies were also tested and the most appropriate ones for Wi-Shoe were selected. Finally, the developed electronics were tested in order to correct possible flaws and prepare for the next versions of the prototypes. The system electronics and the battery are small enough to fit in a special compartment of the sole. The battery can last for at least 6 hours of continuous operation and it can be charged wirelessly at any time, using any Qi-compatible charger.
In parallel, the Wi-Shoe insoles and shoes were designed, developed and tested. This process required several versions of the prototypes to be designed. The Wi-Shoe insole design was the most crucial task, since it was decided to integrate all main system sensors within it. The next step was the selection of the appropriate shoes to be modified in order to be able to integrate the Wi-Shoe ECM. As explained before, it was decided to proceed with the use of two different, existing Podartis models.
Software was also developed in parallel to the electronics. Wi-Shoe answers the actual need of the healthcare, rehabilitation and sport sectors for a person-centric product that will allow continuous monitoring of the subject without the need for an expert’s intervention, promoting the role of “home as care environment”. Data from the Wi-shoe are wirelessly sent to a nearby smartphone for evaluation of the subject's condition and gait performance, as well as for real-time warnings generation. The, so called, Wi-Shoe Lite App, is responsible for acquiring the data generated from the Wi-Shoe and performing basic calculations in real-time, in order to inform the user about critical conditions. During the project, the application has been used with hip fracture rehabilitation patients, in order to help them train on the weight that they need to apply on each foot, in order to speed-up the rehabilitation process. For the athletes, near-real-time information can be provided, such as average speed, distance travelled, energy consumed etc. the Lite App includes a history section, where results from previous sessions are available, in order to allow progress monitoring. Data from the Lite App can also be forwarded to a Professional, cloud-based version of the Wi-Shoe software for full data analysis.
The Wi-Shoe Professional software can be used by experts (medical doctors, physiotherapists, sport medicine experts etc.) for a detailed analysis of the data collected using the Wi-Shoe. It is a friendly software, which is used for: a) managing the data files received from the various users of the Lite App, b) storing the datasets in a database, c) performing the data processing operations to obtain the gait parameters and energy expenditure values, d) providing the expert user with an interface accessible from any common web browser, e) managing the data flow between the Lite App and the server and between the server and the user. Specific parameters calculated through the Professional software include: Vertical Ground Reaction Force, Walking cycle, Cadence, Gait speed, Step length, Centre of Mass vertical displacement, Symmetry ratios, Standing balance/ Centre of Pressure position, Walk ratio and Energy Expenditure.
Wi-Shoe novelty lies on the fact that it is the first time that such an integrated approach for measuring both kinematic gait parameters and energetic expenditure during various activities is presented. Measurements accuracy is also significantly higher, compared to most available market solutions in the same target price range. The final Wi-Shoe prototype version, before actually being delivered for the demonstration, was fully tested, in order to validate the system and algorithms. Both static and dynamic performance of the Wi-Shoe system was evaluated in comparison with professional, “golden standard”, systems with excellent results. Wi-Shoe algorithms were also validated again, using this final prototype.
It should be stressed out that the use of the Wi-Shoe system is much simpler with respect to all currently available solutions, since for the subject it is just a pair of shoes that he/she needs to wear. The usability and friendliness of the software, as well as the comfort of the shoes have been validated by the volunteer users of the Wi-Shoe prototypes. In addition, the Wi-Shoe does not require frequent calibration and most importantly, it can be used at home or wherever the subject prefers in everyday activities. An easy to use calibration device for the Wi-Shoe has also been prepared. The scope of the calibration device is to provide the Wi-Shoe users with an easy way to check that the system sensors are working properly (within specifications) and also with a way of correcting the possible errors. A “quick verification” procedure is also foreseen. This will allow the user to quickly verify that the system is working properly, meaning within the specified accuracy limits, without the need to go through the calibration protocol. The calibration device is controlled through a friendly Android App. This is the User Interface for the calibration device. The user uses the App to store the calibration values in the Wi-Shoe electronics board inside the sole. It also guides the user through the calibration protocol and provides useful information for the device use.
The Wi-Shoe system has been validated and demonstrated with the help of rehabilitation patients from ANIMUS in Greece and with the help of athletes of the Apollon Limassol women’s volleyball team. The demonstration consisted in a short training session, were the patient/athlete and his/her doctor/coach were introduced to the Wi-Shoe and the way to use the shoes and software Application. Then, the subject would wear the shoes and normally walk in a straight line, in order to examine the VGRF curve data and verify that everything is working properly. At that point and, if the subject and doctor/coach were confident to have understood the Wi-Shoe functionality, they were asked to do some data acquisition sessions and upload the data to the server (Professional software).
In order to evaluate also the system’s friendliness, after those first tests, a pair of Wi-Shoes was given to the volunteers for using them by themselves for a prolonged period. They were asked to do at least one session per day and upload the data on the server. After the test, they filled-in a questionnaire, with the help of the Wi-Shoe researchers, in order to get their feedback. The questionnaire covered both Wi-Shoe comfort and Lite App usability issues. Excellent results were obtained.
The Wi-Shoe system presents important benefits for the particular case of rehabilitation patients. Focus, during the project, was put on patients recovering from hip/knee fracture. A hip fracture can present complications due to being immobilized. The goal of rehabilitation after hip fracture surgery is to help the patient begin moving as quickly as possible to avoid the serious complications that can happen with being immobilized in bed. Recovering patients have to use a walking aid, such as a walker or crutches, after surgery. The amount of weight to bear when standing or walking depends on the type of procedure they had. Usually, the amount of weight put on the fractured hip starts from very low levels (for example 10%) and progressively increases with time, until the rehabilitation phase has been completed. Currently, therapists evaluate the amount of weight put on the hip just by watching the patients and their gait. A balance is also used in order to help patients train on the weight that they need to apply on each foot. This procedure can be significantly improved through the use of the Wi-Shoe system. Both therapy at the clinic and at home can be better performed and monitored, facilitating both the therapist and the patient and leading to a quicker recovery.
One of the main Wi-Shoe features is the possibility to measure weight distribution per foot and, obviously, the total weight applied on each foot. Thus, the therapists using Wi-Shoe will be able to monitor in real time and with high precision the actual weight applied. The system is also configurable, so as to provide warnings to the user, when the applied weight exceeds a pre-defined threshold. Furthermore, the Wi-Shoe system can be used by the patient, as a normal shoe, for performing gait training exercises on various surfaces or while going up and down the stairs. In the same time, the system measures all gait related parameters and provides a valuable insight on the patient’s gait. In this way, the therapists will be able to provide specific indications to the patients, in order to improve his/her gait and accelerate the rehabilitation process. Finally, the Wi-Shoe system facilitates a much safer and controlled rehabilitation at home. The patient does not have to rely on his/her own instinct about how much weight to apply on each foot and whether his/her balance and gait are correct.
Regarding the use of Wi-Shoe by professional athletes, the benefits in this case cover two aspects: a) Athletes recovering from an injury and b) Athletes that wish to improve their running efficiency and body posture. The first case is similar to the rehabilitation patients case. Focusing on athletic performance, any displacement that elevates, depresses or moves the centre of mass beyond normal maximum excursion limits wastes energy. Additionally, any abrupt or irregular movement will waste energy even when that movement does not exceed the normal maximum displacement limits of the centre of mass. A successful long-distance runner intuitively takes advantage of these principles. By contrast, the unsuccessful runner lumbers from side to side and lurches up and down in a vicious spiral of exhaustion followed by increased energy expenditure. Wi-Shoe measures Centre of Mass (COM) vertical displacement, as well as Energy Expenditure, Gait speed, Stride frequency, Step length and other parameters, in order to provide the necessary information for avoiding waste of energy and improving running efficiency. Furthermore, the use of the Wi-Shoe system allows detecting problematic body posture conditions on time, thus leading to performance increase and less injuries. The fact that the athlete does not have to do anything particular, other than wearing the Wi-Shoe, facilitates the procedure and makes it possible for the teams to make the tests on the field, without having to visit a clinic.
The following list summarises the main project objectives:
• To improve competitiveness of the participating SMEs through the development and validation of an innovative gait and EE monitoring system
• To enhance, by experimentation, scientific understanding on the way that shoe dimensions affect a person’s mobility
• To develop detail specifications of Wi-Shoe mechanical, electrical and electronic components
• To test the Wi-Shoe system according to the latest standards, to ensure safety, reliability and performance
• To develop the Wi-Shoe App for the web and for smartphones.
• To develop a calibration device for Wi-Shoe
• To demonstrate the functionality of the Wi-Shoe system under real conditions
• To prepare publications and to participate in conferences & trade fairs for the presentation of the Wi-Shoe
• To develop an exploitation plan
Project Results:
The Wi-Shoe main result is an integrated, shoe-based system for measuring kinematic gait parameters and energy expenditure while walking. This system is composed of various parts and modules. Through the process of achieving this main output, several other results were delivered by the consortium partners. They are analysed below in relation with the project work packages (WPs) through which they were delivered.
WP1 - Specification of Wi-Shoe functional and technical requirements and identification of the target sector
The most important output of this WP is the specification of requirements for the Wi-Shoe system. A knowledge base has also been created with the key parameters to measure for each Wi-Shoe end-user category.
The key concept of the Wi-Shoe system is the possibility to analyse data and calculate necessary parameters that allow monitoring subject progress, correct possible errors or detect possible critical conditions. The specific parameters that should be determined with the Wi-Shoe system were defined through this WP and include: Vertical Ground Reaction Force, Walking cycle, Cadence, Gait speed, Step length, Centre of Mass vertical displacement, Plantar pressure distribution, Symmetry ratios, Standing balance, Walk ratio, Energy Expenditure. However, for each end-user category, not all parameters are important. Thus, a study was conducted to identify the most important parameters both for all the pathologies affecting normal walking and for athletes improving running efficiency or recovering after an injury. Almost all pathologies may have a general characterization of the degree of impaired walking only by measuring the spatial parameters (gait speed, step length) and temporal parameters (duration of each phase of the walking cycle) and comparing them with the values of healthy subjects from the same category of age, gender, weight and height. For a more specific characterization for certain pathologies, especially in orthopaedics, it is necessary to study the shape and the maximum values of Vertical Ground Reaction Force curve and Center of Mass vertical displacement. Unilateral pathologies such as stroke, trauma, fracture, use of prosthesis could be more specifically evaluated by means of symmetry parameters: temporal asymmetry and spatial asymmetry. The Energy Expenditure (EE) parameter is also important for a complete characterization of the pathological gait. Study of previous research results on athletes published in scientific publications showed that aside from clinical applications, gait analysis is used in professional sports training to optimize and improve athletic performance. Gait analysis is commonly used in sports biomechanics to help athletes run more efficiently. The Energy Expenditure (EE) parameter is also important for a complete characterization of the athlete’s performance. Regarding the methodology used in the Wi-Shoe system for the calculation of the step length and the gait speed, preliminary research and experiments have also taken place during WP1.
Additionally, one of the aims of WP1 has been to define by experimentation the maximum dimensions (height, width, weight) that the shoe can have in order for the subject to normally walk around. Preliminary experiments were carried out with the help of healthy subjects and patients. The way that the Wi-Shoe components dimensions and weight may affect the subject’s mobility was studied. The experiments were carried out using an older prototype available by partner INCDMTM. Moreover, the gait of patients suffering from osteoarthritis of lower limbs compared to healthy subjects was studied using the same prototype. The experiments showed that gait is not affected, at least in a significant way, by the shoe’s dimensions and weight, as long as those are within reasonable limits. Additionally, a preliminary 3D drawing of the sole was prepared in order to evaluate the available space for the electronics in the Wi-Shoe sole.
As a part of the refinement of the Wi-Shoe concept and the definition of functional and technical requirements, a preliminary study was also made about the power requirements of a Wi-Shoe unit. The objective was to assess the technical feasibility of a solution for supplying power to the proposed system considering the amount of force sensors as well as the design and functional constraints. A preliminary component search was conducted targeting those components with greater weight in terms of power consumption. It was evident that the sensors and the acquisition electronics are the most power-hungry elements of the system representing around 75% of the total energy required. Once the power demanding elements were identified and classified, the power subsystem was defined including specific measures and strategies to reduce the overall power consumption such as on-demand selective switching of modules. More than ten battery technologies available in the market were analysed paying special attention to energy density and performance. Given the space constraints and the significant power required by the circuits and sensors, it was concluded that a rechargeable battery was necessary. Wireless power charging was identified as the most suitable mechanism to charge the battery since it simplifies a lot the process to the end user. The technology is mature and the cost is relatively low. The incorporation of an energy harvesting mechanism to extend battery life was also studied with a focus on piezoelectric transducers. However, market search and literature review revealed that there is currently no cost-effective way of integrating energy harvesting in a system such as the Wi-Shoe.
Furthermore, an additional aim for WP1 has been to conduct a market research to identify new products on the market. Since technology progresses fast, new products become available on the market and new technologies have been presented, thus these needed to be examined before actually starting the Wi-Shoe design. Part of WP1 was devoted to the market research and update of the state of the art. Similar research activities have also been examined. From the research conducted, it is evident that new solutions were introduced since the Wi-Shoe proposal was submitted. A few research projects have also been working on areas similar or complementary to the Wi-Shoe. Most of the available solutions today are addressing the general public and fall under the “fitness” category. Nevertheless, especially through the ongoing research projects, it is expected that several hi-end solutions will be soon available on the market. The most interesting fact that came out through this market and state-of-the-art update is that the market continues to grow for “smart shoe” solutions towards a much lighter system as compared to Wi-shoe. Such systems can therefore assist in a certain way the marketing and promotion of Wi-Shoe System that is much more advanced, both scientifically and technologically thus boosting the sector potentials. From the research it is also evident that the Wi-Shoe is a novel product and the only shoe-based system with advanced features aiming at professional use by both the medical experts and the professional athletes.
An end-user survey has also been conducted. A primary goal for the Wi-Shoe project is to create a new product, with strong market potential. For this purpose, it was particularly important for the technical specifications to meet the requirements of end-users and experts and in the same time to be accessible to a wide category of users. Two questionnaires were prepared and used to get the opinion of different types of end-users (rehabilitation clinics, sports clinics). The results were then analysed and the conclusions drawn from this analysis were used to prepare the technical specifications. Survey results led to a better understanding of the methods used by the end-users and of the gait parameters presenting the main interest for them. Additional information was obtained, such as price expectations and market volume, as well as system priorities from an end-user perspective.
Based on the output of all previous WP1 tasks, the requirements for all Wi-Shoe components were prepared. Those include both hardware and software components. The main focus was the definition of all main system components and their sizing. High-level system specifications also had to be prepared. All those have been defined after taking into consideration all results from WP1 tests, including research, analysis, user and SME needs. Regarding high-level requirements, those derive directly from the user needs, as well as from the experience and needs of the participating SMEs. They include the system target battery life, sampling frequencies, transmission frequency, maximum acceptable system weight and price, target sole height, shoe sizes, maximum dimensions of sensing elements and number of accelerometer axes.
For the main system hardware components, those derive mainly from the application needs, but they are also a consequence of the abovementioned high-level requirements. The specifications prepared cover the force sensors, the inertial measurements, the data transmission module, the data acquisition and pre-processing module and the power module. Dimensions were also specified for key components, such as the force sensors and the battery. Regarding software requirements, the specifications prepared include technology and User Interface related parameters for both software applications (Lite and Professional). The necessary parameters to be presented in each software version have been specified. Finally, the exact use of the Wi-Shoe in the pilots was defined, in order to better specify the demo requirements.
WP2 - Design & Development of the Electromechanical components module (ECM)
The aim of this WP has been the design and development of the Wi-Shoe electronics. The calibration device was also developed through this WP. Additionally, several force measurement technologies were tested, in order to identify the most appropriate ones for use in the Wi-Shoe. The most important results of WP2 were, of course, the prototypes of the ECM (v1) and the calibration device.
Initially, the data acquisition module was designed. The data acquisition process is governed by the microcontroller that acts as the brain of the ECM, triggering sensor acquisition, receiving and storing the data and transmitting it through the data transmission module. There are two types of sensors in the ECM according to their output: analog sensors and digital sensors. The analog sensors include the force sensors, which could be up to 20 in a single shoe. Force sensors must be measured by an appropriate circuitry to convert the voltage values into a digital format. The digital sensors include the inertial sensors, namely the accelerometer and the gyroscope. The inertial sensors are responsible for providing measurements of acceleration applied to the board as well as orientation in the three axes. Configuration and control commands as well as data delivery to the microcontroller is done via serial interface (SPI).
Data transmission was also studied in WP2. The data transmission module is intended to provide the ECM with a way for exchanging commands and data with an external device such as a smartphone or a computer. The primary communication channel is done by an RF wireless link based on the Bluetooth standard. Despite the fact that Bluetooth version 4.0 was initially pointed to meet the requirements of the Wi-Shoe applications, later analysis have concluded that the 2.1 version is more convenient because of its wider compatibility, easier integration and higher throughput. As secondary communication channel, a wired USB interface has also been included in order to facilitate firmware development and testing. A first prototype was developed and tested.
In parallel, an external memory expansion module was developed. The external memory expansion module basically consists in a Flash memory with SPI interface that allows storing sensor data for up to 6 minutes. Data stored in this memory could be uploaded to a computer or smartphone via Bluetooth or USB interface.
The Wi-Shoe calibration device was also designed and developed in WP2. It is used to calibrate the sensors that are integrated in the Wi-Shoe insole. The detailed design of this device has been prepared. The design includes the device mechanics, electronics and user interface. The calibration device has been designed as a vertical stand with a specially designed hand wheel for quick and precise adjustment of calibration points. The device uses a high accuracy digital force gauge as a reference system for the determination of the compression force exercised on the Wi-Shoe insole sensors. The force gauge is mounted on the mechanical stand and, through its monitor, allows the user to see precisely how much force is applied on the sensor under calibration. The actual data reading from the sensors, as well as the storage of the calibration values on the insole EEPROM, is handled by an ECM that is attached on the base of the insole. After reviewing the drawing and deciding on the bottom plate size, the consortium proceeded with the manufacturing of the complete calibration device. It is made of stainless and coated mild steel and some parts have also been polished for aesthetical reasons. A “quick verification” procedure is also foreseen. This allows the user to quickly verify that the system is working properly, meaning within the specified accuracy limits, without the need to go through the calibration protocol. It is based on the use of a custom tip of the calibration device that allows applying force simultaneously to all force sensors.
The user interface to the calibration device is a mobile application for Android smartphones and tablets (Calibration App). This approach enhances the user experience, while it simultaneously reduces the manufacturing cost of the calibration device for Wi-Shoe SMEs and as a consequence for end users. The first version of the Calibration App has been developed through WP2.
A survey was also carried out by contacting several sensor manufacturers, requesting for miniature sensors. After several enquiries, the sensors were selected with price and dimensions being key factors for this choice. The first samples received were tested in the lab to evaluate their performance. Various force measurement technologies have been tested in WP2. In order to be able to compare the most expensive sensor measurements to the measurements of cheaper technologies during walking, an experimental setup had to be prepared. For this reason, the first prototype of the Wi-Shoe insole bottom layer was used. The insole was positioned inside a Podartis shoe to be used for normal walking on a treadmill. The comparison tests showed that cheaper sensors can measure relatively high forces with an acceptable accuracy, but their output is noisy when forces are low. For this reason, it was decided to keep investigating the possibility of using low cost sensors in the Wi-Shoe.
Finally, all developments were tested. This was basically a parallel process to the development. The outputs were a) the updated drawings and prototype of ECM v1, b) the firmware version that was used for the mid-project testing and other tests prior to the actual field demonstration and c) the corrections and approach to reach ECM v2. All hardware flaws and software bugs identified during these testing activities were corrected. The calibration device developed was also tested. The calibration device is quite simple in its operation and its design is based on verified concepts, followed by similar calibrators. Nevertheless, testing was necessary to verify that the device operates according to the specifications and that it is capable of applying the necessary load accurately to the sensors under calibration. The use of the calibration device, in combination with the calibration application and the first available ECM v1 prototype was also tested, mainly from a general functionality and ergonomic point of view. In fact, the calibration device does not directly interact with the application, while the connection of the ECM with the App is based on wireless, Bluetooth communication. The tests confirmed the simplicity in the use of the system.
WP3 - Design & Development of the Wi-Shoe shoe and sole
The main output of WP3 was, of course, the first version of the Wi-Shoe shoe prototype, which was also tested from a mechanical, flexibility and anatomical point of view. Nevertheless, designing and developing the Wi-Shoe insoles and shoes was not that straightforward. In fact, three different versions of the Wi-Shoe insole had to be prepared (initial version, mid-project validation version and final version).
The Wi-Shoe insole design was the most crucial task, since it was decided to integrate all main system sensors within it. Initially, the sensor positions were selected, in order to cover with sensors the most important parts of the foot. Because of the size of the selected sensors, it was expected that up to 18-19 sensors might be possible to be integrated in the Wi-Shoe insole, depending on the exact shape of the selected shoe insole. The sensing area should be large enough to allow an accurate estimate of the spatial coordinates of the center of pressure and the vertical ground reaction force, which are relevant variables to assess the gait biomechanics. For the aforementioned reason, it was decided that the area that is covered by the sensors should be more than the 50% of the total insole area. In order to decide the positions of the load cell sensors plantar pressure distribution during the stance phase of walking in healthy male participants was studied, using an in-shoe plantar pressure analysis system. The highest peak pressures were obtained under the heel, the first metatarsal and the big toe, while the lowest peak pressures were found under the mid-foot. These areas should definitely be covered by sensors in the Wi-Shoe insole. In order to be able to visually present the selected positions, a sample insole available was used to create a CAD drawing. The Wi-Shoe shoes cover the whole range from 37 to 46 EU sizes. At this stage though, the design started with the worst case scenario assumption that less sensors will be used in smaller shoe sizes. For this reason, 37 and a 46 size insoles were initially designed, in order to estimate the number of sensors that could be placed in each insole and their position.
After designing the first Wi-Shoe insole, using a testing, post-operation shoe provided by Podartis, it was necessary to proceed with the design of the insoles that were used for the mid-project validation, as well as for those to be used during the final validation phase. The first step towards the adaptation of the first Wi-Shoe insole to the actual models selected for the trials was the preparation of the 3D CAD drawing of the top insole layer for those models. This allowed getting the exact shape and dimensions for the Wi-Shoe insole in order for it to fit in these shoes, but it also set the design limitations for all insole layers. This top layer had to be as flat as possible at the bottom part, in order to allow easy interfacing with the next layers and it also needed to be as thin as possible, in order to minimize the final Wi-Shoe insole dimensions. Of course, user comfort was also taken into consideration. The 3D CAD drawings were prepared for all Wi-Shoe insole layers.
Since the final designs for the insoles to be used in the final prototypes is meant for use with version-2 electronics (ECM v2), an additional version of the insole (for use in the mid-project testing phase) was also prepared. The insoles designed for mid-project testing are based on the same, existing, PODA models.
Apart from the design, an objective of this task was to deliver the sole and shoe prototypes that were used for the field validation. Initially, a first prototype of the Wi-Shoe insole was prepared using rapid prototyping. It was used for the evaluation of the sensors performance, but also for the selection of the appropriate materials for the insole layer that is positioned on top of the force sensors. Especially for this layer, experiments were conducted using possibly appropriate materials. Insoles were developed using flexible composite materials.
After the delivery of the design of the final insole drawings, the final insoles were produced. Furthermore, through this WP, the insole prototypes for the mid-project validation were produced. Those include a rectangular compartment to allow the use of this insole prototype in combination with ECM v1. The shoes were also produced. The shoes used for the Wi-Shoe validation trials are based on existing Podartis models. This was important in order to guarantee timely delivery of the prototypes, without the need of designing from scratch all shoe features. Using existing models, conformity to standards is also guaranteed. The two selected models are the Podartis Activity and Botero. The first one is an athletic shoe used for athletes training, but also for everyday use. Botero is a casual shoe, suitable for rehabilitation, for patients suffering from diabetes, but also for everyday use. In order to be able to accommodate the Wi-Shoe ECM electronics, the sole of both models had to be appropriately modified. During this stage of the project, only ECM v1 was available, which is a quite large board with respect to the final ECM dimensions. For this reason, it was decided to proceed with the appropriate modification of the sole of just one model. The Activity model has been selected for this purpose, since it is a wider shoe with a thicker sole, which can easily accommodate ECM v1. An appropriate casing has been designed and developed for ECM v1 using rapid prototyping and a corresponding pocket has also been prepared in the Activity No.46 which is the shoe selected for the mid-project testing.
After the delivery of the modified shoes and mid-project Wi-Shoe insole, the already developed ECM v1 module was integrated in the Wi-Shoe sole. The ECM electronics have been placed inside the custom casing, together with the system battery, while the sensors were also connected on the interface board. All these were integrated inside one Wi-Shoe Activity outsole and insole. The same applies for the second shoe of the pair. After the integration, the developed calibration App was used for quickly testing the system and debugging possible issues. Some simple errors in the ECM firmware code were fixed at this stage. The use of the tests at this stage was mainly related to the evaluation of the signals acquired and of the Bluetooth connection quality from inside the shoe. No problems in signal reception were encountered. The calibration device was also used to test the signal acquisition at loaded conditions. Tests were made with loads of 100, 200, 300, 400 and 500 N applied on various sensors. The tests were successful.
Furthermore, through WP3, Static load, dynamic load, flexibility and footwear tests were conducted on the prototypes. The aim of the static test was to study the behaviour of the Wi-Shoe insole, under static load. The Wi-Shoe calibration device was used for this test. All sensors responded quite consistently in terms of static load application. After having obtained the calibration curves, the “quick verification” plate was mounted on the calibration device and was used to apply 80kg of load on the complete, integrated Wi-Shoe insole. The output of the sensors was recorded by the ECM Electronics and was send to a nearby cell phone.
A dynamic test was also performed to study the response of the sensors in the Wi-Shoe insole to impact loads. The Wi-Shoe calibration device was used for this test as well. The force gauge output was connected to a computer (RS-232 serial protocol) and was used to compare the applied, input (reference) load to the actual force measured by the sensor under test, in dynamic conditions. A short script was also prepared in order to be able to automatically issue commands to the force gauge on the calibration device and acquire the readings in same frequency as the ECM readings are made. Finally, the output of a single sensor, positioned inside the Wi-Shoe insole, was compared to the force gauge reference load which was applied on it in a dynamic way. The load applied varied from zero to about 50 kg, following a random curve. The dynamic response of the sensors was very good and followed almost precisely the reference force applied.
The flexibility of the Wi-Shoe prototype was also tested. It has to be stressed out that the WP3 version of the insole was meant for use in the mid-project testing and not for the actual field tests. For this reason, flexibility was not the major priority. To perform the flexibility test, the rear foot area was bended towards the forefoot area. This was repeated for a hundred times. No breaks or cracks were found after the test on any of the Wi-Shoe insole layers or on the box with the electronics. As a conclusion, even though the flexibility of the Wi-shoe prototype was generally acceptable for normal walking, it was necessary to increase the bending ability of Wi-Shoe for the field tests.
Regarding the materials used, the shoes selected for use in the Wi-Shoe trials are based on existing, market-available models. These models comply to CEN/TC 309 “Footwear” standard. Both the Activity and the Botero shoes are compliant to this standard and to all related EU and Italian National regulations in order to be able to be marketed. Since the Wi-Shoe system does not affect the materials used or the manufacturing process, the Wi-Shoe is also compliant to the standard and will be able to be certified before going to production. Since the Wi-Shoe includes also electronic components, those will also have to be certified for conformity to EU regulations. The Wi-Shoe ECM v1 was based on the use of off-the-shelf components, all of which are compliant to EC regulations. The ECM v2 & v3 followed the same principle. Regarding the sensors, those are also off-the-shelf components. Thus, the Wi-Shoe board is, in principle, compliant with the RoHS 2 directive. It will be necessary though to get formal certification before marketing the product.
The comfort of the Wi-Shoe prototype was also examined with the help of healthy volunteers. In order to be able to assess the Wi-Shoe prototype comfort, a questionnaire based on the findings of the Mundermann research team from the University of Calgary has been prepared. Based on the survey conducted, the shoe prototype is not very comfortable in the forefoot. This is something expected, because the thickness of the Wi-Shoe insole used for mid-project validation was still not optimized.
WP4 - Analysis Software Development
The main objective of WP4 has been to deliver the system software. The main results of this WP are the Lite App and the Professional software. The professional software incorporates also the gait analysis and energy expenditure algorithms prepared.
Initially, the mathematical algorithms to be used for the development of the Lite and Professional Software Applications were prepared, following the technical specifications of the Wi-Shoe System (WP2). Temporal parameters based on force measurements, as well as stride length, gait speed and centre of mass are the first categories of parameters which have to be calculated. The algorithms for these parameters have been prepared and simulations to test the functionality of the most complicated of them were also made. Algorithms and methodologies for symmetry ratios, standing balance parameters and their graphical representations - mainly used in neurologic pathologies – were also prepared. Energy expenditure (EE) is an important parameter for the Wi-Shoe project. The methodology used estimates the EE due to muscles movement, which perform mechanical work on the body centre of mass (COM), swing the limbs in relation to the COM and support the body weight. There are several non-invasive methods for estimating the total work performed by the muscles during locomotion. The approach selected is to separate the total work into external and internal work, using the Koenig theorem. The EE is calculated as the sum of the vertical direction external power, the advance direction external power and the internal power.
The Wi-Shoe Lite App was then developed. This is a software application for Android mobile devices and is part of the Wi-Shoe tool kit. Running in a portable device, such as a smartphone, it allows the user to perform gait analysis sessions and rehabilitation exercises, through a simple graphical interface (GUI). After analysing the functional and non-functional requirements of the Lite App, as well as different architectures for its implementation, the App’s GUI, software modules and services were designed and implemented. GUI mock-ups were prepared and shared with the project consortium for feedback. This iterative process led to a first consolidated version of the GUI. The implementation of the data exchange services with the cloud application was done in parallel to GUI design. Finally, the data flow and the data exchange protocol between the App and the ECMs was consolidated. Once all these interfaces with external elements were defined, the development of the main functional modules of the app started.
The interaction of the user with the Lite app is limited to clicking on a few buttons to log in, start/stop the session, connect to ECMs over Bluetooth, visualize results of previous sessions and configure few settings. Despite the apparent simplicity of the interface, the Lite application implements several key operations and non-trivial functionalities that are transparent to the user. On one hand, the application acts as a gateway between the ECMs embedded in the shoes and the cloud application (Professional software), and is also in charge of commanding the ECMs, handling the sensor data received, pre-process this data, format it in a way that is intelligible by the cloud application and transmit it in packages after user request. This is done by a set of modules and services that rely on two different wireless communication interfaces: Bluetooth for the communication with the ECMs and 3G for the communication with the cloud application through RESTful web services. The Lite app also features the option to enable user tracking by means of GPS plus Cell ID methods to get the distance walked at the end of the session, as well as to identify the location where a critical situation might have occurred (for future Wi-Shoe applications). On the other hand, besides gathering and transmitting sensor data obtained in gait sessions for later analysis by the Professional, cloud software, the Lite application features a specific mode for rehabilitation exercises which provides real time feedback about how well the user is performing. This is based on real-time step detection and maximum VGRF calculation per step and foot which is continuously compared with thresholds established by the expert for each patient. When the patient is not performing the exercise as expected, the Lite app warns the user in real time by using colours, sounds and/or vibration to let him/her immediately correct the gait. A score is calculated for every session, to allow for a more effective monitoring of the patient’s progress during the rehabilitation period.
The Wi-Shoe Professional software was also developed and delivered through WP4. This is a software application for Linux and Windows servers. It allows experts and physicians to manage their subjects (patients, athletes) portfolio and assess their condition and progress by analysing gait parameters and energy expenditure. The software implements the data storage, data processing and data visualization layers of the Wi-Shoe system. It complements the other elements of the Wi-Shoe system, namely the ECMs inside the shoe soles and the Lite application for personal handset devices, by providing:
• Long term and scalable data storage both for sensor and user data
• Back-end services to support the internal functionalities, the front-end as well as the Lite application functionalities, such us retrieving user profile and managing file transactions between the handheld device and the server.
• The processing engine to obtain relevant gait parameters from sensor data.
After defining the software architecture and consolidating a GUI design with the help of the end-users, the logical interfaces between the various modules were prepared. The software is made up of the following modules: the Wi-Shoe Data Service (WSDS), the Algorithm Module, the Database Module and the Wi-Shoe Web Application (WSWA). An important sub-module of the WSDS is the task executor. The software could receive sensor data files from diverse Wi-Shoe users simultaneously or at a rate higher than the task processing rate. This bottleneck situation was solved using a sub-module that allows the software to handle concurrent incoming tasks using priority queues and manage these queues so that all data files can be processed and stored without compromising the overall system performance and response time. Regarding the Algorithm Module, simulated data had to be used to test and verify the first complete code implementation since the prototypes were not fully operative yet. Finally, the GUI mock-ups were transformed into dynamic web pages using standard web technologies and languages such as HTML, JavaScript and Ajax. The resulting web interface includes rich navigation features.
As part of the software development methodology, tests were regularly carried out during the implementations of the software functionalities. In fact, every interface, function and back-end service was tested from a lower level first (unit test) to a higher level (integration test) - at the last stages of WP5. A special version of the Lite app was delivered for the mid-project integration tests, by adapting specific modules as well as the interface to facilitate the execution the tests.
Once the shoe prototypes were ready, the complete workflow involving all key functions and interactions between all actors (ECM, Lite app, professional software, patient user, expert user) could be tested. Several updates were made and various issues were solved, leading to the delivery of stable software versions. A software solution was also implemented with respect to the calibration values storage. It consists in preloading in the mobile device a file including the calibration values of all insoles, instead of receiving the particular set of values from the insole.
Tests during the development phase only covered a limited range of scenarios. In order to assure the quality of the code, the applications were made available to the consortium for testing them in various scenarios, as part of WP5 and WP6 activities. This allowed detecting and fixing bugs, as well as receiving feedback and suggestions for improving the tool.
WP5 - System Integration and Validation
WP5 dealt with system integration and validation. This was a key technical work package, which focused on the step-by-step integration and testing of all Wi-Shoe developments, as well as on the upgrade of all components, in order to be able to use the system for the final system demonstration. An important output of this WP were the conclusions after the mid-project testing phase. The final output was, of course, the field version of the Wi-Shoe prototypes. Several hardware and software upgrades were necessary, in order to develop these prototypes. The whole Wi-Shoe system was integrated and tested through this WP. The algorithms and the system were also validated through WP5, by comparison to currently used, professional gait analysis systems.
The first important, integrated prototype delivered was the one used for mid-project experimentation. The Wi-Shoe insoles in these shoes included 19 sensors and an ECM v1 in each shoe. These prototypes were used also as a reference for experimenting on the use of cheaper, alternative force sensors. The calibration device and software, as well as the Lite App was also integrated in the approach.
Once a flexible version of the shoe cabling (FPC) became available, this was also integrated into the Wi-Shoe insole. The mechanical design defined the shape of the circuit and the exact position of sensors and was then translated in a circuit layout in which pads and copper traces were routed from each sensor to the end of a cable extension. The FPC v1 was designed to accommodate up to 19 sensors and to be compatible with the ECM v1. The integrated system (FPC v1 + ECM v1) was used for full tests in Cyprus, in order also to decide about the possibility to use cheaper sensors in selected positions. For these tests, a new, integrated prototype was developed. Different sensor technologies were combined in the same insole, in order to be able to directly compare their measurements. Since there is no ECM capable of measuring simultaneously more than 19 sensors, 2 ECMs were used on the same foot. The Podartis Teradiab shoe was used for these tests.
After the conclusion of the mid-project testing phase, several developments and upgrades were necessary, in order to be able to produce the final Wi-Shoe prototypes that were used in the field demonstrations. Those upgrades included:
- The upgrade of the ECM, in order to be able to read also cheaper sensors’ output.
- The final insole design, considering the final number of sensors used and their positioning.
- Better sensor versions.
- Various software upgrades.
The upgrade of the ECM was necessary for a) correcting all issues encountered with ECM v1, b) integrating the circuit for using also different, cheaper force sensors and c) reducing the size of the board. The ECM v2 was used in combination with both types of force sensors for various tests and it was then further improved in order to deliver the final, ECM v3. Regarding the upgrade of the Wi-Shoe insole, this was produces in accordance with the final selected sensor configuration. For the bottom layer, a new, improved material was used. New, upgraded sensors were also used. The FPC v2 was also produced, based on the final sensors configuration. Two FPCs were designed, one for the 41-43 size range and one for the 44-46 range. They are compatible with both the Activity and the Botero shoes. This approach reduced production cost. The FPCs can be manually trimmed to fit the actual shoe. The design of the FPC v2 is highly versatile. The Lite App, Calibration App and the Professional software were also upgraded, following the results of the mid-project testing. Regarding the final prototypes integration, the Botero and Activity shoes of sizes 41 to 46 were used.
An important task of this WP has also been the, so called, mid-project testing of the Wi-Shoe system. The scope of the mid-project testing was to test all initial project developments in an integrated way, in order to produce the final version of the Wi-Shoe system that was then used for actual validation tests. An important aspect of this testing phase was the definition of the final force sensors configuration inside the Wi-Shoe insole. Apart from the accurate force sensors that have always been considered as the backbone sensors of the Wi-Shoe insole, cheaper sensors have also been studied as a low cost alternative. During the mid-project testing phase, those sensors were further examined, both independently and in combination with actual Wi-Shoe electronics. Additionally, the FPC v1 has been used in combination with ECM v1, in order to verify its properties and deciding whether this approach can be viable also for the final system prototypes. Data collected during the mid-project testing phase were also used for an initial validation of the Wi-Shoe algorithms. Finally, the Wi-Shoe was also examined by the end-users from an ergonomics point of view, as an indication towards the development of the field prototypes.
The first experiments conducted were with the first integrated prototype that included 19 sensors. Those first, reference tests were conducted with the help of an adult male, wearing the no.46 prototype prepared. The acquired data were analysed, in order to measure the contribution of each sensor in the measurements. By examining all data collected during these experiments, it was noticed that usually force is mainly applied to specific parts of the insole. This was an information to consider regarding the possibility of completely removing those sensors (for cost reduction) or substituting them with lower cost sensors.
The next tests regarded the possibility of using cheaper force sensors. After testing the sensors independently and given the fact that those sensors are meant for use in a lower cost version of the system, it was concluded that their performance is acceptable. In principle though, those sensors should be used where forces are generally lower and contribute by a smaller percentage to the total VGRF.
Once the FPC v1 was delivered, this was also tested in combination with force sensors and ECM v1. Communication between the ECM and the Lite App was also tested during these tests. Through these experiments, FPC functionality was confirmed in real walking conditions. It was decided that the FPC approach will be used also in the final prototypes for the field demonstration. As a next step, the Teradiab prototype was tested with more accurate and lower accuracy (cheaper) sensors. As a conclusion, the use of low cost sensors was confirmed as possible for the Wi-Shoe lower cost version. The positions in which the Flexiforce sensors are used affects the system’s overall performance in different ways. In general, though, forces measured in specific insole positions were constantly very low, which meant that at least 2-3 sensors could be removed, in order to lower system cost, without affecting overall performance.
During the mid-project testing phase, comfort testing was made using also the help of volunteer patients of ANIMUS. All patients were recovering from a hip surgery. The results were not far from what was observed with the healthy volunteers (WP3). The results are normal and expected, not only because of the previous tests with healthy subjects, but also because the thickness of the Wi-Shoe insole used for mid-project validation was still not optimized.
The data acquired from the mid-project testing, but also from the early prototypes, were used for preliminary algorithms validation. Special attention was paid to the step detection algorithm, since practically almost all parameters depend on accurate step detection. Summarizing the results of this algorithms validation phase, all algorithms and formulas have been validated at least from a functionality point of view. Preliminary filtering of the data, for correcting the hysteresis effect of the force sensors, was also introduced after this phase.
After the delivery of the final Wi-Shoe prototype version, this was also fully tested through this WP, in order also to validate the system and algorithms. Ten adult volunteers participated in the experiments. The golden standard against which Wi-Shoe measurements were compared is the professional force-plates system available in CERTH. The Vicon motion capture system was also used to calculate step length and gait speed. Additionally, the Tekscan HR Mat was used to capture the person’s balance (force distribution between the two feet).
The volunteers where initially trained on the use of the Wi-Shoe system and were asked to wear the Wi-Shoe and familiarize with it. They were then asked to stand on the Tekscan HR Mat, in order to measure the pressure distribution between the two feet. They were also asked to stand with both feet on a force plate, in order to accurately measure their weight. Finally, the volunteers were asked to walk on the corridor, making sure that they would also step on a force place while walking normally. At least two steps with the right foot and two steps with the left foot where required, before concluding the test. During the whole test duration, the users would also wear the Wi-Shoe and data were contemporarily recorder by both the Wi-Shoe and the golden standard systems. Apart from collecting Wi-Shoe data and using them for the validation, the tests allowed also testing the communications between the Wi-Shoe, the Lite App and the Professional Software. During the tests, data was recorded using the Lite App and was transmitted to the Professional software, as it would normally happen in real conditions. No communication problems were detected. The Bluetooth connection between the Wi-Shoe and the Lite App can easily operate with no problems, even when the devices are about 10-meters apart. The validation tests allowed a direct comparison between the Wi-Shoe and the force plates measurements, especially in terms of VGRF, which is the main parameter on which several other calculations are based. Regarding weight measurement of all subjects, Wi-Shoe proved to be really accurate, as expected. Of course, the most interesting comparison was the one between dynamic measurements. The differences between the VGRF curve calculated using the Wi-Shoe and the ones calculated using the force plate were very small. The subjects’ weight distribution between the two feet, in a static position was also measured with the help of the Tekscan HR Mat system. This additional test was performed with 6 of the participating volunteers, as an additional verification system for Wi-Shoe performance. The subjects were asked to stand on the Mat in a comfortable position, wearing also the Wi-Shoe. As expected, based also on the force plates testing, Wi-Shoe performance in terms of static load measurement was excellent. As earlier stated, the Vicon motion capture system was used to calculate step length and gait speed. Wi-Shoe algorithms for gait speed and step length were also used with Wi-Shoe collected data. The calculation of those spatio-temporal parameters was not fully validated earlier, so these results were important for the full system validation. According to the obtained results the accuracy in measuring the spatio-temporal parameters is in the order of 1.5-3%. Moreover, collected data were also used to complete the algorithms validation. The step detection algorithm detected correctly all stance and balance phases.
The final Wi-Shoe prototype was also used for field testing with the help of the end-users. The system was used by both APOLLON and ANIMUS, in their own facilities. The prototype used for this testing was the one prepared and used also in the full-scale lab validations. The scope of this testing was to allow the end-users to familiarise with the Wi-Shoe and the mobile Application, as well as to help them with the use of the Professional software. The calibration device and App was also presented to them and they were asked to do a full calibration procedure by themselves. The whole experience was important for preparing the end-users for the demonstration phase.
In ANIMUS, after a short presentation of the Wi-Shoe system and App, the responsible doctor asked three patients, that had already provided their consent, to wear the shoes and move around the premises. The doctor was using the App to setup and start the acquisition. A questionnaire was then used to collect the feedback of both the doctor and the patients. A second doctor of ANIMUS was also asked to participate in the study, by simply using the Application and answering the questionnaire. Both doctors were generally capable of performing all the required operations. Regarding the patients, they were asked to evaluate the prototype from a comfort point of view, as previously done also for the mid-project testing prototype. The same questionnaire as before was used. The results, even though based on a very small sample of patients, are much better with respect to the mid-project testing. This was expected, since the prototype was significantly improved in terms of comfort, thickness and flexibility. Regarding the Professional software, the two ANIMUS doctors were introduced to its functionalities and were driven through the various screens. Specific comments were received regarding the possibility of changing various colours and texts in the interface. The calibration device and App were also introduced to the ANIMUS doctors. They were both asked to do a full calibration of one of the shoes, following the on-screen instructions. The procedure was found by both of them to be simple and intuitive.
Similar to the testing in ANIMUS, the system was also tested by APOLLON end-users in Cyprus, mainly in terms of comfort and software friendliness. CyRIC explained the use of the App to the club’s manager. Two athletes were also invited to wear the Wi-Shoe prototype and perform some basic training exercises, as well as walking. The team manager was using the App to setup and start the acquisition. A questionnaire was then used to collect the feedback of both the manager and the athletes. The manager found the Application very easy to use. Regarding the two athletes, they were asked to evaluate the prototype from a comfort point of view. The results are better with respect to the mid-project testing, even though a bit lower values were recorded, with respect to the answers of the ANIMUS patients. This is probably related to the fact that athletes are used to wear very comfortable, often custom-made, shoes while exercising. As in the ANIMUS case, the Professional software and the calibration device and App were also introduced to the club’s manager. Positive feedback was received.
WP6 - Demonstration of the Wi-Shoe system
WP6 dealt with system demonstration. The main objective was to demonstrate the system to the participating SMEs and end-users and to explain its functionality. The system was demonstrated with the help of the two end-users, ANIMUS and APOLLON. During the demonstration, all bugs encountered in the software were corrected.
Minor upgrades in the prototypes were required before actually starting the demonstration in both sites. The first improvement that was necessary was the integration of a miniature power off switch on the sole of both Wi-Shoe versions. Even though the power consumption of the Wi-Shoe has been significantly reduced with ECM v3, it was still more practical to have the possibility to completely deactivate the system when it is not used. This was especially useful for the demonstration phase. As a second improvement, wireless charging was also implemented in this final, field version of the Wi-Shoe prototypes. This was a feature planned since the project beginning, but it was impractical to integrate in previous versions of the prototypes. At this stage though, wireless charging was a significant advantage and simplified a lot the use of the system for the end-users. In order to charge the shoes’ battery, the user only has to turn them on (using the abovementioned switch) and place them on the charging pad.
Regarding the actual demonstration, the Wi-Shoe demonstration with rehabilitation patients took place in ANIMUS. Shoes of sizes 42-45 were available for this demonstration, based on the Botero model. In total, seven hip fracture and knee surgery patients participated in this demonstration. The demonstration consisted in a short training session, were the patient and his/her doctor were introduced to the Wi-Shoe and the way to use the shoes and software Application. Then, the patient would wear the shoes and normally walk in a straight line, in order to examine the VGRF curve data and verify that everything is working properly. At that point and, if the patient and doctor were confident to have understood the Wi-Shoe functionality, they were asked to do some data acquisition sessions and upload the data to the server (Professional software). In order to evaluate also the system’s friendliness, after those first tests, a pair of Wi-Shoes was given to the volunteers for using them by themselves for a week in their rooms. They were asked to do at least one session per day and upload the data on the server. After the test, they filled-in a questionnaire, with the help of the Wi-Shoe researchers, in order to get their feedback. The questionnaire covered both Wi-Shoe comfort and Lite App usability issues. The prototypes used, especially in terms of comfort, are identical to the ones used during the WP5 field tests. In fact, all seven volunteers found the shoes very comfortable. Regarding the Lite App friendliness evaluation, a significant improvement, also with respect to WP5 tests, was the fact that the Bluetooth pairing procedure, between the shoes and the mobile App was simplified. All users found the application very intuitive.
The Wi-Shoe was also evaluated with the help of professional athletes from the APOLLON women’s volleyball team. Shoes of sizes 41-43 were available for this demonstration, based on the Activity model (sports shoe). The demonstration consisted in a short training session, were the athletes were introduced to the Wi-Shoe and the way to use the shoes and software Application. Then, the athletes would wear the shoes and normally walk in a straight line, in order to examine the VGRF curve data and verify that everything is working properly. At that point and, if the athletes were confident to have understood the Wi-Shoe functionality, they were asked to do some data acquisition sessions and upload the data to the server (Professional software).
In order to evaluate also the system’s friendliness, after those first tests, a pair of Wi-Shoes was given to each of the two volunteers for using them by themselves for a month, during various activities (short walks, longer walks, running). Data were also collected during volleyball training sessions. They were then asked to upload the data on the server after each test. After the test, the athletes filled-in a questionnaire, with the help of the Wi-Shoe researchers, in order to get their feedback. The questionnaire covered both Wi-Shoe comfort and Lite App usability issues.
As in the ANIMUS case, the athletes were asked to evaluate the prototype’s comfort, as well as the friendliness of the Lite App. The shoes were generally found to be comfortable enough. The software was also judged as intuitive.
From the positive feedback received during the demonstration phase, as well as from the previous, full testing sessions of the Wi-Shoe system (D5.1) it is clear that the Wi-Shoe has achieved its goal of being an easy to use, non-intrusive system. Of course, specific things will be improved after the project, in order to produce the market version of the Wi-Shoe, including:
• Addition of an extra, soft layer over the other Wi-Shoe insole layers, in order to improve comfort
• Continuous improvement of the Lite App, especially in terms of simplification of the Bluetooth pairing procedure
• Improvement of the Professional software, especially in terms of automated advice and comments to the user and the expert
• Sensors permanently fixed in the insole, in order to increase robustness.
Data collected during the demonstration phase were also analysed for further algorithms improvement.
WP7 - Dissemination and Exploitation
The objectives of WP7 were mainly related to the dissemination of project results and the preparation for their exploitation. Additionally, through WP7, training of the SMEs was organised. The results of WP7 include the project website, the various publications, the project dissemination material (logo, brochures, presentations, posters, video), the dedicated workshop that was organised and, of course, the Interim and Final plans for use and dissemination of knowledge.
Regarding the training activities, their aim was to allow the commercial partners of the project to understand all details related to the Wi-Shoe production, assembly and use, as well as the science behind the algorithms. A training session was organised for the Wi-Shoe SMEs and end-users in ANIMUS premises. The training session included presentations by the researchers and a lot of interaction with the SMEs and end-users, in order to explain all details and respond to various questions. A live demonstration of the system was also organised.
Additionally, a “Manufacturing and assembly manual" was prepared, in order to facilitate results uptake by the SMEs. A “System operation manual" has also been prepared, describing the use of the Wi-Shoe Lite App and Professional software. Furthermore, a document was delivered, as an attachment to the operation manual, regarding the mathematical algorithms underlying the application software.
Regarding the project results dissemination, several activities took place. Dissemination activities included the project presentation in the following events:
• The 4th Biochemistry & Exercise Physiology conference, held on 24-26/10/2014 in Trikala, Greece by CERTH
• The Mechatronics, Integronics And Adaptronics - Smart Specialisation Conference, held on 13-15th of May 2015 in Bucharest, Romania by INCDMTM
• The International Neurology and rehabilitation Meeting (INeReM), held this year in Istanbul, TURKEY, in the period 4th - 6th of June by a poster prepared mainly by INCDMTM and CyRIC
• The icSPORTS 2015 congress, held in Lisbon, Portugal, during 15 - 17 November 2015 by CyRIC
Publications were also made in the following magazines/journals/newspapers:
• Horizon magazine, funded by the European Commission
• The Romanian Review Precision Mechanics, Optics & Mechatronics
• #DisruptCyprus electronic magazine
• “Erevna” newspaper, Greece
• “The Cyprus weekly” newspaper
Two different project brochures were prepared for use in the various dissemination activities. The first one was an initial project introduction. The second one was prepared for use in the latest dissemination events and presents more information. In order to present the project in an easy to comprehend way, also for the general audience, a video has also been prepared by CyRIC. The video is available on the website. A project presentation, open to the public, has also been prepared and has been made available through the Wi-Shoe website. It has been used for presenting the project to possible users of the technology (either through web-based seminars/discussions or through face to face meetings).
As a final dissemination event, a dedicated workshop was organised. The workshop was used to present the project results to various stakeholders and interested members of the general audience. Of course, researchers from the scientific community were invited and participated in the event.
Regarding the exploitation of project results, after an initial patent search, the SMEs proceeded with a detailed analysis of the patentability of the Wi-Shoe system. The exploitation plan was also developed. In principle, all four SMEs have co-ownership of all results that are of direct interest to them, based on their activities. A detailed business and marketing plan has been prepared by the SMEs, with the help of the RTDs and especially CyRIC. The targeted markets of Wi-Shoe are the Medical and Rehabilitation sectors –and more particularly the segments that use gait monitoring - and the Sports Sector. Because of the professional nature of the product, Wi-Shoe is targeting as potential customers hospitals & rehabilitation clinics, physiotherapists and sport medicine doctors rather than the end-users (patients and athletes) themselves. Initial focus will be on the European market. Nevertheless, the US and rest of the world markets will follow.
WP8 - Consortium Management
The scope of WP8 was to coordinate communication between partners and towards the commission and to make sure that the project reaches its objectives. IPR issues were also handled through this work package. Additionally, ethical issues and approvals were obtained through this WP, in order to be able to perform the system validation and demonstration with the help of the volunteers.
Regarding the exploitation of the project results, no changes were made to the initial Exploitation plan presented in the DoW and the Consortium Agreement which was acceptable by SME partners and includes all clauses with regards to Joint Ownership as stated within FP7/IP Guide.
All publications were first submitted to the Coordinator and IPR Manager for review. The Coordinator and IPR Manager also presented the publications to the SMEs for approval. In this way, no IPR sensitive issues were published.
Ethical aspects have also been dealt with through this task. Because of the need to involve volunteers, all ethical issues have been carefully examined. Informed consent forms have been developed for both end-user institutions and will be used with all subjects participating in the project as volunteers. Since the Wi-Shoe research is one of minimal risk, an approval from legal national bodies was not necessary. Nevertheless, the Ethics Committee of ANIMUS reviewed and approved the Protocol and Informed Consent Forms to be used by both organizations (ANIMUS and APOLLON) and issued the Ethical Clearance documents.
Regarding the project management, all objectives and milestones have been reached. Agendas, Minutes and Action plans for each meeting were prepared on-time and uploaded in the project management platform. Six consortium meetings have been organized since the project beginning (kick-off, 6M, 12M, 15M, 18M and 24M meetings). An Exploitation meeting also took place. Several Skype teleconferences have also been held for which minutes are available as well. A review meeting took place on M12 and was combined with the 12M consortium meeting.
Regarding communication management, the Coordinator has been in direct contact with the project officer either by email or phone and communicated when necessary to either get assistance or discuss any pending issues. For communication between partners the following tools were used: Skype, Email, Teleconference and the project management Platform Basecamp.
Potential Impact:
The targeted markets of Wi-Shoe are the Medical and Rehabilitation sectors –and more particularly the segments that use gait monitoring - and the Sports Sector. The list below, summarises possible user sub-categories for the Wi-Shoe system.
• Diabetic foot patients
• Patients suffering from: Lumbar spinal pains and bearing joints of the legs, Algofunctional Decompensated Gonarthrosis, Peripheral neuromotor lesions, Motor deficits due to paralysis of a hemi-body and central neuromotor diseases (e.g. stroke), Gait disorders related to ageing
• Patients recovering from fractures
• Patients suffering from lower limb osteoarthritis
• Patients recovering from hip/ knee/ ankle arthroplasty
• Parkinson’s disease patients
• Patients using a prosthesis
• Patients recovering from ankle/hip fusion surgery
• Patients affected by Pes cavus or Hallux Valgus
• Spinal cord injury recovering patients
• Patients suffering from fibromyalgia
• Completely healthy athletes for improving their performance
• Athletes recovering from injury through a gait rehabilitation/ training program.
Large amounts of money are spent every year for gait parameters and EE monitoring, but even so, it is not possible to use gait monitoring with all those patients for whom that would be beneficial. The fact that currently available systems require a controlled environment and an expert’s presence, in addition to the fact that their cost is several thousands of Euros, leads to their limited use. Adopting the Wi-Shoe solution which does not have any of these limitations, gait and energy expenditure analyses would be performed as often as required, in order to better assist patient recovery, earlier diseases diagnosis and sport performance improvement.
Wi-Shoe impact in the targeted sectors is multi-fold. Current cost for gait and EE monitoring is a large portion of the total cost of the rehabilitation procedure for patients requiring such monitoring. For professional athletes, it is an expense that only the richest clubs can afford. Firstly, the initial investment is high, since the cheapest gait monitoring system costs about 10.5k Euros and does not offer any EE monitoring possibility. A combination of this system with a professional EE monitoring system would require another 36k Euros. In addition, currently available systems and procedures require the subject to be at the hospital, clinic or training facility for the test. Furthermore, these gait monitoring systems require frequent calibration and the preparation for the test is quite laborious, since the subject has to wear all the necessary equipment. All these procedures lead to specialized personnel man hours spent for the system setup, calibration and control during the test. The use of the Wi-Shoe system is much simpler, since for the subject it is just a pair of shoes that he/she needs to wear.
The Wi-Shoe system does not require frequent calibration and most importantly, it can be used at home or wherever the subject prefers in everyday activities. The Wi-Shoe cost is expected to be significantly lower with respect to systems of comparable capabilities and accuracy and so it will be possible for the clinic or club to have several systems available for the subjects to use. Less time for the patient spent at the hospital, means lower cost for the clinic and the patient. Additionally, the subjects benefit from a continuous monitoring throughout their activities and not just during the few minutes at the hospital or training facility. Real-time monitoring means more data for the analysis, higher precision in the gait parameters calculation and increased possibility in detecting problematic situations that may not be detected during a conventional monitoring session.
Furthermore, the Wi-Shoe system allows remote monitoring of the subjects, without the need for continuous expert intervention. In this way, Wi-Shoe improves and supports the monitored subject’s sense of independence, which is of major psychological importance, especially in the case of elder people. The lack of cables running on the subject’s legs is of major importance for this advanced sense of independence. Increased sense of independence means better life quality as well. Because of the reduced number of clinic visits needed with the Wi-Shoe approach, the patient can spend more time at home, while simultaneously being monitored by an expert. In addition, the use of the Wi-Shoe system will allow resources optimization for clinics and hospitals, which has a direct impact on practically everybody. The doctors, for example, currently following patients during gait monitoring sessions, with Wi-Shoe will be available for other tasks inside the clinic. Thus, doctors or other experts will be used in more efficient way, reducing waiting.
In order to be able to quantify the potential impact of Wi-Shoe, focus was put on selected end-user categories: stoke patients, diabetes patients, the elderly and professional athletes.
Stroke is a common condition, especially for the elderly. The number of stroke patients in Europe is continuously raising and the annual cost becomes more and more difficult to deal with for patient families and for hospitals. After a stroke the patient needs continuous monitoring, treatment and help. Stroke patients are among the possible Wi-Shoe users, since they could benefit from the possibility to use the system at home, after release from the hospital. People that have suffered and survived a stroke in the EU are estimated at about 7.000.000. Additionally, 1.100.000 new stroke events are registered each year, with this number continuously raising, especially due to the growth of the over-65 population. The number of stroke events in Europe is projected to rise from 1.1 million to 1.5 million per year by 2025, largely due to the ageing population.
Another important subsector that is directly targeted by the Wi-Shoe system is the Diabetes patients sector and their monitoring. Diabetic patients often suffer from diabetic neuropathy. A patient suffering from this medical condition cannot feel parts of their body (dysesthesia) and most commonly the feet. Since the diabetics have dry skin that can very easily be wounded, if a patient during walking exercises more pressure to a foot then this area has a high probability of developing an open wound. Because of the dysesthesia, the patient will not be able to feel the wound and this can lead to extreme conditions, since diabetic patient wounds are very difficult to heal. Doctors usually ask patients to self-examine their feet every day in order to find possible open wounds and they will subscribe them special custom made boots that help them balance their weight distribution and thus avoiding further foot damage. Of course, clinics that have a gait monitoring system can examine the patient’s weight distribution before a bad distribution leads to the actual problem. Wi-Shoe in this case would be extremely useful because the medical team could detect in advance the incorrect weight (force) distribution and thus completely avoiding the problem. There are about 60 million people with diabetes in the European region, or about 10.3% of men and 9.6% of women aged 25 years and over. Prevalence of diabetes is increasing among all ages in the European region, mostly due to increases in overweight and obesity, unhealthy diet and physical inactivity.
Another area of high interest for Wi-Shoe is related to aging and elderly care. Aging leads to increases in gait variability which may explain the large incidence of falls in the elderly. Body weight support training may be utilized to improve gait and minimize falls. However, before initiating rehabilitation protocols, baseline studies are needed to identify the effect of body weight support on elderly gait variability. These can be made using the Wi-Shoe system. According to EUROSTAT, the proportion of the total European population older than 65 is set to increase from 16.1% in 2000 to 27.5% by 2050, while the proportion of the population aged over 80 years (3.6% in 2000) is expected to reach 10% by 2050. Thus, more than 100.000.000 people in the EU will belong to this category by 2020.
Regarding professional athletes in the EU and considering particularly data about football, basketball and volleyball players, those are about 690.000. The use of WI-Shoe for athletes will allow detecting problematic body posture conditions on time, thus leading to performance increase and less injuries. The fact that the athlete does not have to do anything particular, other than wearing the Wi-Shoe, facilitates the procedure and makes it possible for the teams to make the tests on the field, without having to visit a clinic. Additionally, the use of the Wi-Shoe can be very beneficial for recovering athletes. The Wi-Shoe can be used to monitor on a continuous basis the athlete’s applied weight distribution, balance and other important gait related parameters. This, combined with the athlete’s dedicated effort for quick recovery, can lead to an optimal recovery time. It is also important to highlight the benefits of Wi-Shoe for athletes that wish to improve their running efficiency. Any displacement that elevates, depresses or moves the centre of mass beyond normal maximum excursion limits wastes energy. Additionally, any abrupt or irregular movement will waste energy even when that movement does not exceed the normal maximum displacement limits of the centre of mass. A successful long-distance runner intuitively takes advantage of these principles. Wi-Shoe measures Centre of Mass (COM) vertical displacement, as well as Energy Expenditure, Gait speed, Stride frequency, Step length and other parameters, in order to provide the necessary information for avoiding waste of energy and improving running efficiency.
Wi-Shoe accomplished dissemination activities:
The project was presented in the following occasions:
• The 4th Biochemistry & Exercise Physiology conference, held on 24-26/10/2014 in Trikala, Greece by CERTH
The Wi-Shoe project and initial approach has been presented in the 4th Biochemistry and Exercise Physiology conference that was held on 2014 October 24-26 in Trikala, Greece. Dr Giannis Giakas of CERTH presented the paper.
• The Mechatronics, Integronics And Adaptronics - Smart Specialisation Conference, held on 13-15th of May 2015 in Bucharest, Romania by INCDMTM
The Wi-Shoe system was presented by Dr Mihai Margaritescu of INCDMTM in the MECHATRONICS, INTEGRONICS AND ADAPTRONICS - SMART SPECIALISATION Conference, that was held in Bucharest, Romania at the 13-15th of May 2015 in the ROMEXPO Exhibition Centre. It was an opportunity to present the Wi-Shoe project to researchers, to members of the Chamber of Commerce of Bucharest and to the general public
• The International Neurology and rehabilitation Meeting (INeReM), held this year in Istanbul, TURKEY, in the period 4th - 6th of June by a poster prepared mainly by INCDMTM and CyRIC
A Wi-Shoe short paper and a poster presentation has been accepted in the INeREM meeting in Istanbul. This has been a first opportunity to present the project approach and preliminary results in the medical sector. The International Neurology and rehabilitation Meeting (INeReM) was held in Istanbul, Turkey, in the period 4th - 6th of June 2015. Wi-Shoe consortium presented a poster. The abstract was also published in the proceedings.
• The icSPORTS 2015 congress, held in Lisbon, Portugal, during 15 - 17 November 2015 by CyRIC
The congress, held in Lisbon, Portugal, during 15 - 17 November 2015 was an excellent chance to present the Wi-Shoe applicability in the sports field to a very qualified audience to many possible system users. This was the last conference presentation during project lifetime and the most detailed one in terms of results that could be shared with the audience.
Both an oral presentation and a poster were used to present Wi-Shoe by Dr Alessandro Giusti from CyRIC. Wi-Shoe was also included in the conference proceedings and was listed in R&D sponsors of the conference
Publications were also made in the following magazines/journals/newspapers:
• Horizon magazine, funded by the European Commission
The Wi-Shoe project was one of the three EU-funded projects included in the article entitled "Wireless ‘smart trainers’ give real-time advice" in the Horizon Research & Innovation Magazine (http://horizon-magazine.eu/article/wireless-smart-trainers-give-real-time-advice_en.html).
• The Romanian Review Precision Mechanics, Optics & Mechatronics
An article on Wi-Shoe has been published in the journal towards the end of the project. The article is entitled: “Gait Parameters and Energy Expenditure Assessment with the novel wearable Wi-Shoe System”.
• #DisruptCyprus electronic magazine
An article regarding the completion of the Wi-Shoe validation phase has been published in the #DisruptCyprus electronic magazine and website (http://www.disruptcyprus.com/innovation/63-news-innovation/526-cyric-and-its-partners-develop-a-smart-wireless-shoe-insole-for-medical-and-sport-applications).
• “Erevna” newspaper, Greece
An article was published in the “H EREVNA” local Greek newspaper regarding the successful Wi-Shoe workshop that was organized towards the end of the project. The article is in Greek and targeted mainly the Thessaly community. Generic project information about the main results is also included in this publication.
• “The Cyprus weekly” newspaper
An article was also published at the English language, CYPRUS WEEKLY newspaper on December 2015.
Apart from the previous activities, two different project brochures were prepared. Those are available for download through the project website: http://www.wishoe.eu/index.php/results. A video has also been prepared by CyRIC and is available on the website.
As a final dissemination event, a dedicated workshop was organised. Presentations were made by all project RTDs, as well as by PMED, as a representative of the SMEs. The workshop took place on December 11th 2015 in Trikala, Greece. It was used to present the project results to various stakeholders and interested members of the general audience. Of course, researchers from the scientific community were invited and participated in the event.
Wi-Shoe results exploitation:
Because of the professional nature of the product, Wi-Shoe is targeting as potential customers hospitals & rehabilitation clinics, physiotherapists and sport medicine doctors rather than the end-users (patients and athletes) themselves.
A business plan has been prepared by the project SMEs, taking into consideration the costs associated to Wi-Shoe, such as production and manufacturing costs, operational expenses and marketing costs. Operational expenses cover Insurance, Accounting and Legal expenses as well as various other expenses such as utilities, equipment, service and maintenance. The main output of the financial analysis made, based on the Financial Indexes, is that Wi-Shoe is an efficient and very attractive investment.
The calibration device was also studied as an independent product. The scope of the calibration device is to provide the Wi-Shoe users with an easy way to check that the system sensors are working properly (within specifications) and also with a way of correcting the possible errors. The device could be sold as product but the SME partners have also considered the possibility of offering the calibration of the Wi-Shoe as a service.
The Exploitation Plan is in full accordance with the DoW and the Consortium Agreement was signed by all partners before the project start. There have been no recorded objections or apparent deviations by any partner against the Exploitation plan of the DoW.
List of Websites:
www.wishoe.eu
Gait parameters monitoring and energetic expenditure calculation is of high importance for patients recovering from diseases that affect movement, such as stroke or for patients in the rehabilitation phase after a surgery. The same applies to professional athletes either (a) in the phase of recovery from a lower limb injury or (b) performing a sport requiring very precise body posture and/or movement control, like baseball or triple jump.
The Wi-Shoe project developed a completely non-intrusive wearable shoe-based system used for measuring kinematic gait parameters and energetic expenditure during various activities. The Wi-Shoe system integrates miniature sensors in a custom designed shoe sole. Different types of shoes can be made based on novel shoe sole designs. During the project, two different shoes were developed; a casual, everyday shoe and a sports shoe. Wi-Shoe answers the actual need of the healthcare, rehabilitation and sport sectors for a person-centric product that will allow continuous monitoring of the subject without the need for an expert’s intervention, promoting the role of “home as care environment”.
Data from the Wi-Shoe are wirelessly sent to a nearby smartphone for evaluation of the subject's condition and gait performance, as well as for real-time warnings generation. Data can also be forwarded to a Professional, cloud-based version of the Wi-Shoe software for full data analysis. The system offers also historical analysis of results.
Wi-Shoe novelty lies on the fact that it is the first time that such an integrated approach for measuring both kinematic gait parameters and energetic expenditure during various activities is presented. Measurements accuracy is also significantly higher, compared to most available market solutions in the same target price range. A lower cost version of the Wi-Shoe has also been developed, for applications that do not require increased precision in the measurements. Furthermore, the use of the Wi-Shoe system is much simpler with respect to all currently available solutions, since for the subject it is just a pair of shoes that he/she needs to wear. The Wi-Shoe does not require frequent calibration and most importantly, it can be used at home or wherever the subject prefers in everyday activities. An easy to use calibration device for the Wi-Shoe has also been prepared. A dedicated application is available for guiding the users through the calibration procedure. In addition, the Wi-Shoe allows remote monitoring of the subjects, without the need for continuous expert intervention. In this way, Wi-Shoe improves and supports the monitored subject’s sense of independence, which is of major psychological importance.
Project Context and Objectives:
The aim of the Wi-Shoe project has been to develop a completely non-intrusive wearable shoe-based system used for measuring kinematic gait parameters and energetic expenditure during various activities. Focus was put on rehabilitation patients and athletes that wish to improve their walking/running efficiency.
The Wi-Shoe system integrates miniature sensors in a custom designed shoe sole. Different types of shoes can be made based on the novel shoe sole designs prepared. During the project, two different shoes were developed, based on existing models offered by the consortium partner Podartis: a casual, everyday shoe and a sports shoe. As a first step in the project, a study was made to identify kinematic gait parameters that need to be monitored for all possible end-user categories. Calculation methods for all parameters have been studied. Preliminary experiments were conducted for understanding the maximum dimensions and weight that a shoe can have for normal walking. This allowed for a maximum preliminary system sizing. An end-user survey was also conducted to identify the most suitable specifications from a user perspective. Survey results were used for the preparation of the technical specifications. Based on these activities, the technical requirements were prepared. These included high level requirements, as well as specific requirements for the main hardware & software components. A preliminary concept drawing of the sole was prepared in order to estimate available space for the electronics.
After this phase, the shoe electronics were prepared, including the data acquisition and transmission module. A preliminary prototype was first developed for testing & integration purposes. Various force measurement technologies were also tested and the most appropriate ones for Wi-Shoe were selected. Finally, the developed electronics were tested in order to correct possible flaws and prepare for the next versions of the prototypes. The system electronics and the battery are small enough to fit in a special compartment of the sole. The battery can last for at least 6 hours of continuous operation and it can be charged wirelessly at any time, using any Qi-compatible charger.
In parallel, the Wi-Shoe insoles and shoes were designed, developed and tested. This process required several versions of the prototypes to be designed. The Wi-Shoe insole design was the most crucial task, since it was decided to integrate all main system sensors within it. The next step was the selection of the appropriate shoes to be modified in order to be able to integrate the Wi-Shoe ECM. As explained before, it was decided to proceed with the use of two different, existing Podartis models.
Software was also developed in parallel to the electronics. Wi-Shoe answers the actual need of the healthcare, rehabilitation and sport sectors for a person-centric product that will allow continuous monitoring of the subject without the need for an expert’s intervention, promoting the role of “home as care environment”. Data from the Wi-shoe are wirelessly sent to a nearby smartphone for evaluation of the subject's condition and gait performance, as well as for real-time warnings generation. The, so called, Wi-Shoe Lite App, is responsible for acquiring the data generated from the Wi-Shoe and performing basic calculations in real-time, in order to inform the user about critical conditions. During the project, the application has been used with hip fracture rehabilitation patients, in order to help them train on the weight that they need to apply on each foot, in order to speed-up the rehabilitation process. For the athletes, near-real-time information can be provided, such as average speed, distance travelled, energy consumed etc. the Lite App includes a history section, where results from previous sessions are available, in order to allow progress monitoring. Data from the Lite App can also be forwarded to a Professional, cloud-based version of the Wi-Shoe software for full data analysis.
The Wi-Shoe Professional software can be used by experts (medical doctors, physiotherapists, sport medicine experts etc.) for a detailed analysis of the data collected using the Wi-Shoe. It is a friendly software, which is used for: a) managing the data files received from the various users of the Lite App, b) storing the datasets in a database, c) performing the data processing operations to obtain the gait parameters and energy expenditure values, d) providing the expert user with an interface accessible from any common web browser, e) managing the data flow between the Lite App and the server and between the server and the user. Specific parameters calculated through the Professional software include: Vertical Ground Reaction Force, Walking cycle, Cadence, Gait speed, Step length, Centre of Mass vertical displacement, Symmetry ratios, Standing balance/ Centre of Pressure position, Walk ratio and Energy Expenditure.
Wi-Shoe novelty lies on the fact that it is the first time that such an integrated approach for measuring both kinematic gait parameters and energetic expenditure during various activities is presented. Measurements accuracy is also significantly higher, compared to most available market solutions in the same target price range. The final Wi-Shoe prototype version, before actually being delivered for the demonstration, was fully tested, in order to validate the system and algorithms. Both static and dynamic performance of the Wi-Shoe system was evaluated in comparison with professional, “golden standard”, systems with excellent results. Wi-Shoe algorithms were also validated again, using this final prototype.
It should be stressed out that the use of the Wi-Shoe system is much simpler with respect to all currently available solutions, since for the subject it is just a pair of shoes that he/she needs to wear. The usability and friendliness of the software, as well as the comfort of the shoes have been validated by the volunteer users of the Wi-Shoe prototypes. In addition, the Wi-Shoe does not require frequent calibration and most importantly, it can be used at home or wherever the subject prefers in everyday activities. An easy to use calibration device for the Wi-Shoe has also been prepared. The scope of the calibration device is to provide the Wi-Shoe users with an easy way to check that the system sensors are working properly (within specifications) and also with a way of correcting the possible errors. A “quick verification” procedure is also foreseen. This will allow the user to quickly verify that the system is working properly, meaning within the specified accuracy limits, without the need to go through the calibration protocol. The calibration device is controlled through a friendly Android App. This is the User Interface for the calibration device. The user uses the App to store the calibration values in the Wi-Shoe electronics board inside the sole. It also guides the user through the calibration protocol and provides useful information for the device use.
The Wi-Shoe system has been validated and demonstrated with the help of rehabilitation patients from ANIMUS in Greece and with the help of athletes of the Apollon Limassol women’s volleyball team. The demonstration consisted in a short training session, were the patient/athlete and his/her doctor/coach were introduced to the Wi-Shoe and the way to use the shoes and software Application. Then, the subject would wear the shoes and normally walk in a straight line, in order to examine the VGRF curve data and verify that everything is working properly. At that point and, if the subject and doctor/coach were confident to have understood the Wi-Shoe functionality, they were asked to do some data acquisition sessions and upload the data to the server (Professional software).
In order to evaluate also the system’s friendliness, after those first tests, a pair of Wi-Shoes was given to the volunteers for using them by themselves for a prolonged period. They were asked to do at least one session per day and upload the data on the server. After the test, they filled-in a questionnaire, with the help of the Wi-Shoe researchers, in order to get their feedback. The questionnaire covered both Wi-Shoe comfort and Lite App usability issues. Excellent results were obtained.
The Wi-Shoe system presents important benefits for the particular case of rehabilitation patients. Focus, during the project, was put on patients recovering from hip/knee fracture. A hip fracture can present complications due to being immobilized. The goal of rehabilitation after hip fracture surgery is to help the patient begin moving as quickly as possible to avoid the serious complications that can happen with being immobilized in bed. Recovering patients have to use a walking aid, such as a walker or crutches, after surgery. The amount of weight to bear when standing or walking depends on the type of procedure they had. Usually, the amount of weight put on the fractured hip starts from very low levels (for example 10%) and progressively increases with time, until the rehabilitation phase has been completed. Currently, therapists evaluate the amount of weight put on the hip just by watching the patients and their gait. A balance is also used in order to help patients train on the weight that they need to apply on each foot. This procedure can be significantly improved through the use of the Wi-Shoe system. Both therapy at the clinic and at home can be better performed and monitored, facilitating both the therapist and the patient and leading to a quicker recovery.
One of the main Wi-Shoe features is the possibility to measure weight distribution per foot and, obviously, the total weight applied on each foot. Thus, the therapists using Wi-Shoe will be able to monitor in real time and with high precision the actual weight applied. The system is also configurable, so as to provide warnings to the user, when the applied weight exceeds a pre-defined threshold. Furthermore, the Wi-Shoe system can be used by the patient, as a normal shoe, for performing gait training exercises on various surfaces or while going up and down the stairs. In the same time, the system measures all gait related parameters and provides a valuable insight on the patient’s gait. In this way, the therapists will be able to provide specific indications to the patients, in order to improve his/her gait and accelerate the rehabilitation process. Finally, the Wi-Shoe system facilitates a much safer and controlled rehabilitation at home. The patient does not have to rely on his/her own instinct about how much weight to apply on each foot and whether his/her balance and gait are correct.
Regarding the use of Wi-Shoe by professional athletes, the benefits in this case cover two aspects: a) Athletes recovering from an injury and b) Athletes that wish to improve their running efficiency and body posture. The first case is similar to the rehabilitation patients case. Focusing on athletic performance, any displacement that elevates, depresses or moves the centre of mass beyond normal maximum excursion limits wastes energy. Additionally, any abrupt or irregular movement will waste energy even when that movement does not exceed the normal maximum displacement limits of the centre of mass. A successful long-distance runner intuitively takes advantage of these principles. By contrast, the unsuccessful runner lumbers from side to side and lurches up and down in a vicious spiral of exhaustion followed by increased energy expenditure. Wi-Shoe measures Centre of Mass (COM) vertical displacement, as well as Energy Expenditure, Gait speed, Stride frequency, Step length and other parameters, in order to provide the necessary information for avoiding waste of energy and improving running efficiency. Furthermore, the use of the Wi-Shoe system allows detecting problematic body posture conditions on time, thus leading to performance increase and less injuries. The fact that the athlete does not have to do anything particular, other than wearing the Wi-Shoe, facilitates the procedure and makes it possible for the teams to make the tests on the field, without having to visit a clinic.
The following list summarises the main project objectives:
• To improve competitiveness of the participating SMEs through the development and validation of an innovative gait and EE monitoring system
• To enhance, by experimentation, scientific understanding on the way that shoe dimensions affect a person’s mobility
• To develop detail specifications of Wi-Shoe mechanical, electrical and electronic components
• To test the Wi-Shoe system according to the latest standards, to ensure safety, reliability and performance
• To develop the Wi-Shoe App for the web and for smartphones.
• To develop a calibration device for Wi-Shoe
• To demonstrate the functionality of the Wi-Shoe system under real conditions
• To prepare publications and to participate in conferences & trade fairs for the presentation of the Wi-Shoe
• To develop an exploitation plan
Project Results:
The Wi-Shoe main result is an integrated, shoe-based system for measuring kinematic gait parameters and energy expenditure while walking. This system is composed of various parts and modules. Through the process of achieving this main output, several other results were delivered by the consortium partners. They are analysed below in relation with the project work packages (WPs) through which they were delivered.
WP1 - Specification of Wi-Shoe functional and technical requirements and identification of the target sector
The most important output of this WP is the specification of requirements for the Wi-Shoe system. A knowledge base has also been created with the key parameters to measure for each Wi-Shoe end-user category.
The key concept of the Wi-Shoe system is the possibility to analyse data and calculate necessary parameters that allow monitoring subject progress, correct possible errors or detect possible critical conditions. The specific parameters that should be determined with the Wi-Shoe system were defined through this WP and include: Vertical Ground Reaction Force, Walking cycle, Cadence, Gait speed, Step length, Centre of Mass vertical displacement, Plantar pressure distribution, Symmetry ratios, Standing balance, Walk ratio, Energy Expenditure. However, for each end-user category, not all parameters are important. Thus, a study was conducted to identify the most important parameters both for all the pathologies affecting normal walking and for athletes improving running efficiency or recovering after an injury. Almost all pathologies may have a general characterization of the degree of impaired walking only by measuring the spatial parameters (gait speed, step length) and temporal parameters (duration of each phase of the walking cycle) and comparing them with the values of healthy subjects from the same category of age, gender, weight and height. For a more specific characterization for certain pathologies, especially in orthopaedics, it is necessary to study the shape and the maximum values of Vertical Ground Reaction Force curve and Center of Mass vertical displacement. Unilateral pathologies such as stroke, trauma, fracture, use of prosthesis could be more specifically evaluated by means of symmetry parameters: temporal asymmetry and spatial asymmetry. The Energy Expenditure (EE) parameter is also important for a complete characterization of the pathological gait. Study of previous research results on athletes published in scientific publications showed that aside from clinical applications, gait analysis is used in professional sports training to optimize and improve athletic performance. Gait analysis is commonly used in sports biomechanics to help athletes run more efficiently. The Energy Expenditure (EE) parameter is also important for a complete characterization of the athlete’s performance. Regarding the methodology used in the Wi-Shoe system for the calculation of the step length and the gait speed, preliminary research and experiments have also taken place during WP1.
Additionally, one of the aims of WP1 has been to define by experimentation the maximum dimensions (height, width, weight) that the shoe can have in order for the subject to normally walk around. Preliminary experiments were carried out with the help of healthy subjects and patients. The way that the Wi-Shoe components dimensions and weight may affect the subject’s mobility was studied. The experiments were carried out using an older prototype available by partner INCDMTM. Moreover, the gait of patients suffering from osteoarthritis of lower limbs compared to healthy subjects was studied using the same prototype. The experiments showed that gait is not affected, at least in a significant way, by the shoe’s dimensions and weight, as long as those are within reasonable limits. Additionally, a preliminary 3D drawing of the sole was prepared in order to evaluate the available space for the electronics in the Wi-Shoe sole.
As a part of the refinement of the Wi-Shoe concept and the definition of functional and technical requirements, a preliminary study was also made about the power requirements of a Wi-Shoe unit. The objective was to assess the technical feasibility of a solution for supplying power to the proposed system considering the amount of force sensors as well as the design and functional constraints. A preliminary component search was conducted targeting those components with greater weight in terms of power consumption. It was evident that the sensors and the acquisition electronics are the most power-hungry elements of the system representing around 75% of the total energy required. Once the power demanding elements were identified and classified, the power subsystem was defined including specific measures and strategies to reduce the overall power consumption such as on-demand selective switching of modules. More than ten battery technologies available in the market were analysed paying special attention to energy density and performance. Given the space constraints and the significant power required by the circuits and sensors, it was concluded that a rechargeable battery was necessary. Wireless power charging was identified as the most suitable mechanism to charge the battery since it simplifies a lot the process to the end user. The technology is mature and the cost is relatively low. The incorporation of an energy harvesting mechanism to extend battery life was also studied with a focus on piezoelectric transducers. However, market search and literature review revealed that there is currently no cost-effective way of integrating energy harvesting in a system such as the Wi-Shoe.
Furthermore, an additional aim for WP1 has been to conduct a market research to identify new products on the market. Since technology progresses fast, new products become available on the market and new technologies have been presented, thus these needed to be examined before actually starting the Wi-Shoe design. Part of WP1 was devoted to the market research and update of the state of the art. Similar research activities have also been examined. From the research conducted, it is evident that new solutions were introduced since the Wi-Shoe proposal was submitted. A few research projects have also been working on areas similar or complementary to the Wi-Shoe. Most of the available solutions today are addressing the general public and fall under the “fitness” category. Nevertheless, especially through the ongoing research projects, it is expected that several hi-end solutions will be soon available on the market. The most interesting fact that came out through this market and state-of-the-art update is that the market continues to grow for “smart shoe” solutions towards a much lighter system as compared to Wi-shoe. Such systems can therefore assist in a certain way the marketing and promotion of Wi-Shoe System that is much more advanced, both scientifically and technologically thus boosting the sector potentials. From the research it is also evident that the Wi-Shoe is a novel product and the only shoe-based system with advanced features aiming at professional use by both the medical experts and the professional athletes.
An end-user survey has also been conducted. A primary goal for the Wi-Shoe project is to create a new product, with strong market potential. For this purpose, it was particularly important for the technical specifications to meet the requirements of end-users and experts and in the same time to be accessible to a wide category of users. Two questionnaires were prepared and used to get the opinion of different types of end-users (rehabilitation clinics, sports clinics). The results were then analysed and the conclusions drawn from this analysis were used to prepare the technical specifications. Survey results led to a better understanding of the methods used by the end-users and of the gait parameters presenting the main interest for them. Additional information was obtained, such as price expectations and market volume, as well as system priorities from an end-user perspective.
Based on the output of all previous WP1 tasks, the requirements for all Wi-Shoe components were prepared. Those include both hardware and software components. The main focus was the definition of all main system components and their sizing. High-level system specifications also had to be prepared. All those have been defined after taking into consideration all results from WP1 tests, including research, analysis, user and SME needs. Regarding high-level requirements, those derive directly from the user needs, as well as from the experience and needs of the participating SMEs. They include the system target battery life, sampling frequencies, transmission frequency, maximum acceptable system weight and price, target sole height, shoe sizes, maximum dimensions of sensing elements and number of accelerometer axes.
For the main system hardware components, those derive mainly from the application needs, but they are also a consequence of the abovementioned high-level requirements. The specifications prepared cover the force sensors, the inertial measurements, the data transmission module, the data acquisition and pre-processing module and the power module. Dimensions were also specified for key components, such as the force sensors and the battery. Regarding software requirements, the specifications prepared include technology and User Interface related parameters for both software applications (Lite and Professional). The necessary parameters to be presented in each software version have been specified. Finally, the exact use of the Wi-Shoe in the pilots was defined, in order to better specify the demo requirements.
WP2 - Design & Development of the Electromechanical components module (ECM)
The aim of this WP has been the design and development of the Wi-Shoe electronics. The calibration device was also developed through this WP. Additionally, several force measurement technologies were tested, in order to identify the most appropriate ones for use in the Wi-Shoe. The most important results of WP2 were, of course, the prototypes of the ECM (v1) and the calibration device.
Initially, the data acquisition module was designed. The data acquisition process is governed by the microcontroller that acts as the brain of the ECM, triggering sensor acquisition, receiving and storing the data and transmitting it through the data transmission module. There are two types of sensors in the ECM according to their output: analog sensors and digital sensors. The analog sensors include the force sensors, which could be up to 20 in a single shoe. Force sensors must be measured by an appropriate circuitry to convert the voltage values into a digital format. The digital sensors include the inertial sensors, namely the accelerometer and the gyroscope. The inertial sensors are responsible for providing measurements of acceleration applied to the board as well as orientation in the three axes. Configuration and control commands as well as data delivery to the microcontroller is done via serial interface (SPI).
Data transmission was also studied in WP2. The data transmission module is intended to provide the ECM with a way for exchanging commands and data with an external device such as a smartphone or a computer. The primary communication channel is done by an RF wireless link based on the Bluetooth standard. Despite the fact that Bluetooth version 4.0 was initially pointed to meet the requirements of the Wi-Shoe applications, later analysis have concluded that the 2.1 version is more convenient because of its wider compatibility, easier integration and higher throughput. As secondary communication channel, a wired USB interface has also been included in order to facilitate firmware development and testing. A first prototype was developed and tested.
In parallel, an external memory expansion module was developed. The external memory expansion module basically consists in a Flash memory with SPI interface that allows storing sensor data for up to 6 minutes. Data stored in this memory could be uploaded to a computer or smartphone via Bluetooth or USB interface.
The Wi-Shoe calibration device was also designed and developed in WP2. It is used to calibrate the sensors that are integrated in the Wi-Shoe insole. The detailed design of this device has been prepared. The design includes the device mechanics, electronics and user interface. The calibration device has been designed as a vertical stand with a specially designed hand wheel for quick and precise adjustment of calibration points. The device uses a high accuracy digital force gauge as a reference system for the determination of the compression force exercised on the Wi-Shoe insole sensors. The force gauge is mounted on the mechanical stand and, through its monitor, allows the user to see precisely how much force is applied on the sensor under calibration. The actual data reading from the sensors, as well as the storage of the calibration values on the insole EEPROM, is handled by an ECM that is attached on the base of the insole. After reviewing the drawing and deciding on the bottom plate size, the consortium proceeded with the manufacturing of the complete calibration device. It is made of stainless and coated mild steel and some parts have also been polished for aesthetical reasons. A “quick verification” procedure is also foreseen. This allows the user to quickly verify that the system is working properly, meaning within the specified accuracy limits, without the need to go through the calibration protocol. It is based on the use of a custom tip of the calibration device that allows applying force simultaneously to all force sensors.
The user interface to the calibration device is a mobile application for Android smartphones and tablets (Calibration App). This approach enhances the user experience, while it simultaneously reduces the manufacturing cost of the calibration device for Wi-Shoe SMEs and as a consequence for end users. The first version of the Calibration App has been developed through WP2.
A survey was also carried out by contacting several sensor manufacturers, requesting for miniature sensors. After several enquiries, the sensors were selected with price and dimensions being key factors for this choice. The first samples received were tested in the lab to evaluate their performance. Various force measurement technologies have been tested in WP2. In order to be able to compare the most expensive sensor measurements to the measurements of cheaper technologies during walking, an experimental setup had to be prepared. For this reason, the first prototype of the Wi-Shoe insole bottom layer was used. The insole was positioned inside a Podartis shoe to be used for normal walking on a treadmill. The comparison tests showed that cheaper sensors can measure relatively high forces with an acceptable accuracy, but their output is noisy when forces are low. For this reason, it was decided to keep investigating the possibility of using low cost sensors in the Wi-Shoe.
Finally, all developments were tested. This was basically a parallel process to the development. The outputs were a) the updated drawings and prototype of ECM v1, b) the firmware version that was used for the mid-project testing and other tests prior to the actual field demonstration and c) the corrections and approach to reach ECM v2. All hardware flaws and software bugs identified during these testing activities were corrected. The calibration device developed was also tested. The calibration device is quite simple in its operation and its design is based on verified concepts, followed by similar calibrators. Nevertheless, testing was necessary to verify that the device operates according to the specifications and that it is capable of applying the necessary load accurately to the sensors under calibration. The use of the calibration device, in combination with the calibration application and the first available ECM v1 prototype was also tested, mainly from a general functionality and ergonomic point of view. In fact, the calibration device does not directly interact with the application, while the connection of the ECM with the App is based on wireless, Bluetooth communication. The tests confirmed the simplicity in the use of the system.
WP3 - Design & Development of the Wi-Shoe shoe and sole
The main output of WP3 was, of course, the first version of the Wi-Shoe shoe prototype, which was also tested from a mechanical, flexibility and anatomical point of view. Nevertheless, designing and developing the Wi-Shoe insoles and shoes was not that straightforward. In fact, three different versions of the Wi-Shoe insole had to be prepared (initial version, mid-project validation version and final version).
The Wi-Shoe insole design was the most crucial task, since it was decided to integrate all main system sensors within it. Initially, the sensor positions were selected, in order to cover with sensors the most important parts of the foot. Because of the size of the selected sensors, it was expected that up to 18-19 sensors might be possible to be integrated in the Wi-Shoe insole, depending on the exact shape of the selected shoe insole. The sensing area should be large enough to allow an accurate estimate of the spatial coordinates of the center of pressure and the vertical ground reaction force, which are relevant variables to assess the gait biomechanics. For the aforementioned reason, it was decided that the area that is covered by the sensors should be more than the 50% of the total insole area. In order to decide the positions of the load cell sensors plantar pressure distribution during the stance phase of walking in healthy male participants was studied, using an in-shoe plantar pressure analysis system. The highest peak pressures were obtained under the heel, the first metatarsal and the big toe, while the lowest peak pressures were found under the mid-foot. These areas should definitely be covered by sensors in the Wi-Shoe insole. In order to be able to visually present the selected positions, a sample insole available was used to create a CAD drawing. The Wi-Shoe shoes cover the whole range from 37 to 46 EU sizes. At this stage though, the design started with the worst case scenario assumption that less sensors will be used in smaller shoe sizes. For this reason, 37 and a 46 size insoles were initially designed, in order to estimate the number of sensors that could be placed in each insole and their position.
After designing the first Wi-Shoe insole, using a testing, post-operation shoe provided by Podartis, it was necessary to proceed with the design of the insoles that were used for the mid-project validation, as well as for those to be used during the final validation phase. The first step towards the adaptation of the first Wi-Shoe insole to the actual models selected for the trials was the preparation of the 3D CAD drawing of the top insole layer for those models. This allowed getting the exact shape and dimensions for the Wi-Shoe insole in order for it to fit in these shoes, but it also set the design limitations for all insole layers. This top layer had to be as flat as possible at the bottom part, in order to allow easy interfacing with the next layers and it also needed to be as thin as possible, in order to minimize the final Wi-Shoe insole dimensions. Of course, user comfort was also taken into consideration. The 3D CAD drawings were prepared for all Wi-Shoe insole layers.
Since the final designs for the insoles to be used in the final prototypes is meant for use with version-2 electronics (ECM v2), an additional version of the insole (for use in the mid-project testing phase) was also prepared. The insoles designed for mid-project testing are based on the same, existing, PODA models.
Apart from the design, an objective of this task was to deliver the sole and shoe prototypes that were used for the field validation. Initially, a first prototype of the Wi-Shoe insole was prepared using rapid prototyping. It was used for the evaluation of the sensors performance, but also for the selection of the appropriate materials for the insole layer that is positioned on top of the force sensors. Especially for this layer, experiments were conducted using possibly appropriate materials. Insoles were developed using flexible composite materials.
After the delivery of the design of the final insole drawings, the final insoles were produced. Furthermore, through this WP, the insole prototypes for the mid-project validation were produced. Those include a rectangular compartment to allow the use of this insole prototype in combination with ECM v1. The shoes were also produced. The shoes used for the Wi-Shoe validation trials are based on existing Podartis models. This was important in order to guarantee timely delivery of the prototypes, without the need of designing from scratch all shoe features. Using existing models, conformity to standards is also guaranteed. The two selected models are the Podartis Activity and Botero. The first one is an athletic shoe used for athletes training, but also for everyday use. Botero is a casual shoe, suitable for rehabilitation, for patients suffering from diabetes, but also for everyday use. In order to be able to accommodate the Wi-Shoe ECM electronics, the sole of both models had to be appropriately modified. During this stage of the project, only ECM v1 was available, which is a quite large board with respect to the final ECM dimensions. For this reason, it was decided to proceed with the appropriate modification of the sole of just one model. The Activity model has been selected for this purpose, since it is a wider shoe with a thicker sole, which can easily accommodate ECM v1. An appropriate casing has been designed and developed for ECM v1 using rapid prototyping and a corresponding pocket has also been prepared in the Activity No.46 which is the shoe selected for the mid-project testing.
After the delivery of the modified shoes and mid-project Wi-Shoe insole, the already developed ECM v1 module was integrated in the Wi-Shoe sole. The ECM electronics have been placed inside the custom casing, together with the system battery, while the sensors were also connected on the interface board. All these were integrated inside one Wi-Shoe Activity outsole and insole. The same applies for the second shoe of the pair. After the integration, the developed calibration App was used for quickly testing the system and debugging possible issues. Some simple errors in the ECM firmware code were fixed at this stage. The use of the tests at this stage was mainly related to the evaluation of the signals acquired and of the Bluetooth connection quality from inside the shoe. No problems in signal reception were encountered. The calibration device was also used to test the signal acquisition at loaded conditions. Tests were made with loads of 100, 200, 300, 400 and 500 N applied on various sensors. The tests were successful.
Furthermore, through WP3, Static load, dynamic load, flexibility and footwear tests were conducted on the prototypes. The aim of the static test was to study the behaviour of the Wi-Shoe insole, under static load. The Wi-Shoe calibration device was used for this test. All sensors responded quite consistently in terms of static load application. After having obtained the calibration curves, the “quick verification” plate was mounted on the calibration device and was used to apply 80kg of load on the complete, integrated Wi-Shoe insole. The output of the sensors was recorded by the ECM Electronics and was send to a nearby cell phone.
A dynamic test was also performed to study the response of the sensors in the Wi-Shoe insole to impact loads. The Wi-Shoe calibration device was used for this test as well. The force gauge output was connected to a computer (RS-232 serial protocol) and was used to compare the applied, input (reference) load to the actual force measured by the sensor under test, in dynamic conditions. A short script was also prepared in order to be able to automatically issue commands to the force gauge on the calibration device and acquire the readings in same frequency as the ECM readings are made. Finally, the output of a single sensor, positioned inside the Wi-Shoe insole, was compared to the force gauge reference load which was applied on it in a dynamic way. The load applied varied from zero to about 50 kg, following a random curve. The dynamic response of the sensors was very good and followed almost precisely the reference force applied.
The flexibility of the Wi-Shoe prototype was also tested. It has to be stressed out that the WP3 version of the insole was meant for use in the mid-project testing and not for the actual field tests. For this reason, flexibility was not the major priority. To perform the flexibility test, the rear foot area was bended towards the forefoot area. This was repeated for a hundred times. No breaks or cracks were found after the test on any of the Wi-Shoe insole layers or on the box with the electronics. As a conclusion, even though the flexibility of the Wi-shoe prototype was generally acceptable for normal walking, it was necessary to increase the bending ability of Wi-Shoe for the field tests.
Regarding the materials used, the shoes selected for use in the Wi-Shoe trials are based on existing, market-available models. These models comply to CEN/TC 309 “Footwear” standard. Both the Activity and the Botero shoes are compliant to this standard and to all related EU and Italian National regulations in order to be able to be marketed. Since the Wi-Shoe system does not affect the materials used or the manufacturing process, the Wi-Shoe is also compliant to the standard and will be able to be certified before going to production. Since the Wi-Shoe includes also electronic components, those will also have to be certified for conformity to EU regulations. The Wi-Shoe ECM v1 was based on the use of off-the-shelf components, all of which are compliant to EC regulations. The ECM v2 & v3 followed the same principle. Regarding the sensors, those are also off-the-shelf components. Thus, the Wi-Shoe board is, in principle, compliant with the RoHS 2 directive. It will be necessary though to get formal certification before marketing the product.
The comfort of the Wi-Shoe prototype was also examined with the help of healthy volunteers. In order to be able to assess the Wi-Shoe prototype comfort, a questionnaire based on the findings of the Mundermann research team from the University of Calgary has been prepared. Based on the survey conducted, the shoe prototype is not very comfortable in the forefoot. This is something expected, because the thickness of the Wi-Shoe insole used for mid-project validation was still not optimized.
WP4 - Analysis Software Development
The main objective of WP4 has been to deliver the system software. The main results of this WP are the Lite App and the Professional software. The professional software incorporates also the gait analysis and energy expenditure algorithms prepared.
Initially, the mathematical algorithms to be used for the development of the Lite and Professional Software Applications were prepared, following the technical specifications of the Wi-Shoe System (WP2). Temporal parameters based on force measurements, as well as stride length, gait speed and centre of mass are the first categories of parameters which have to be calculated. The algorithms for these parameters have been prepared and simulations to test the functionality of the most complicated of them were also made. Algorithms and methodologies for symmetry ratios, standing balance parameters and their graphical representations - mainly used in neurologic pathologies – were also prepared. Energy expenditure (EE) is an important parameter for the Wi-Shoe project. The methodology used estimates the EE due to muscles movement, which perform mechanical work on the body centre of mass (COM), swing the limbs in relation to the COM and support the body weight. There are several non-invasive methods for estimating the total work performed by the muscles during locomotion. The approach selected is to separate the total work into external and internal work, using the Koenig theorem. The EE is calculated as the sum of the vertical direction external power, the advance direction external power and the internal power.
The Wi-Shoe Lite App was then developed. This is a software application for Android mobile devices and is part of the Wi-Shoe tool kit. Running in a portable device, such as a smartphone, it allows the user to perform gait analysis sessions and rehabilitation exercises, through a simple graphical interface (GUI). After analysing the functional and non-functional requirements of the Lite App, as well as different architectures for its implementation, the App’s GUI, software modules and services were designed and implemented. GUI mock-ups were prepared and shared with the project consortium for feedback. This iterative process led to a first consolidated version of the GUI. The implementation of the data exchange services with the cloud application was done in parallel to GUI design. Finally, the data flow and the data exchange protocol between the App and the ECMs was consolidated. Once all these interfaces with external elements were defined, the development of the main functional modules of the app started.
The interaction of the user with the Lite app is limited to clicking on a few buttons to log in, start/stop the session, connect to ECMs over Bluetooth, visualize results of previous sessions and configure few settings. Despite the apparent simplicity of the interface, the Lite application implements several key operations and non-trivial functionalities that are transparent to the user. On one hand, the application acts as a gateway between the ECMs embedded in the shoes and the cloud application (Professional software), and is also in charge of commanding the ECMs, handling the sensor data received, pre-process this data, format it in a way that is intelligible by the cloud application and transmit it in packages after user request. This is done by a set of modules and services that rely on two different wireless communication interfaces: Bluetooth for the communication with the ECMs and 3G for the communication with the cloud application through RESTful web services. The Lite app also features the option to enable user tracking by means of GPS plus Cell ID methods to get the distance walked at the end of the session, as well as to identify the location where a critical situation might have occurred (for future Wi-Shoe applications). On the other hand, besides gathering and transmitting sensor data obtained in gait sessions for later analysis by the Professional, cloud software, the Lite application features a specific mode for rehabilitation exercises which provides real time feedback about how well the user is performing. This is based on real-time step detection and maximum VGRF calculation per step and foot which is continuously compared with thresholds established by the expert for each patient. When the patient is not performing the exercise as expected, the Lite app warns the user in real time by using colours, sounds and/or vibration to let him/her immediately correct the gait. A score is calculated for every session, to allow for a more effective monitoring of the patient’s progress during the rehabilitation period.
The Wi-Shoe Professional software was also developed and delivered through WP4. This is a software application for Linux and Windows servers. It allows experts and physicians to manage their subjects (patients, athletes) portfolio and assess their condition and progress by analysing gait parameters and energy expenditure. The software implements the data storage, data processing and data visualization layers of the Wi-Shoe system. It complements the other elements of the Wi-Shoe system, namely the ECMs inside the shoe soles and the Lite application for personal handset devices, by providing:
• Long term and scalable data storage both for sensor and user data
• Back-end services to support the internal functionalities, the front-end as well as the Lite application functionalities, such us retrieving user profile and managing file transactions between the handheld device and the server.
• The processing engine to obtain relevant gait parameters from sensor data.
After defining the software architecture and consolidating a GUI design with the help of the end-users, the logical interfaces between the various modules were prepared. The software is made up of the following modules: the Wi-Shoe Data Service (WSDS), the Algorithm Module, the Database Module and the Wi-Shoe Web Application (WSWA). An important sub-module of the WSDS is the task executor. The software could receive sensor data files from diverse Wi-Shoe users simultaneously or at a rate higher than the task processing rate. This bottleneck situation was solved using a sub-module that allows the software to handle concurrent incoming tasks using priority queues and manage these queues so that all data files can be processed and stored without compromising the overall system performance and response time. Regarding the Algorithm Module, simulated data had to be used to test and verify the first complete code implementation since the prototypes were not fully operative yet. Finally, the GUI mock-ups were transformed into dynamic web pages using standard web technologies and languages such as HTML, JavaScript and Ajax. The resulting web interface includes rich navigation features.
As part of the software development methodology, tests were regularly carried out during the implementations of the software functionalities. In fact, every interface, function and back-end service was tested from a lower level first (unit test) to a higher level (integration test) - at the last stages of WP5. A special version of the Lite app was delivered for the mid-project integration tests, by adapting specific modules as well as the interface to facilitate the execution the tests.
Once the shoe prototypes were ready, the complete workflow involving all key functions and interactions between all actors (ECM, Lite app, professional software, patient user, expert user) could be tested. Several updates were made and various issues were solved, leading to the delivery of stable software versions. A software solution was also implemented with respect to the calibration values storage. It consists in preloading in the mobile device a file including the calibration values of all insoles, instead of receiving the particular set of values from the insole.
Tests during the development phase only covered a limited range of scenarios. In order to assure the quality of the code, the applications were made available to the consortium for testing them in various scenarios, as part of WP5 and WP6 activities. This allowed detecting and fixing bugs, as well as receiving feedback and suggestions for improving the tool.
WP5 - System Integration and Validation
WP5 dealt with system integration and validation. This was a key technical work package, which focused on the step-by-step integration and testing of all Wi-Shoe developments, as well as on the upgrade of all components, in order to be able to use the system for the final system demonstration. An important output of this WP were the conclusions after the mid-project testing phase. The final output was, of course, the field version of the Wi-Shoe prototypes. Several hardware and software upgrades were necessary, in order to develop these prototypes. The whole Wi-Shoe system was integrated and tested through this WP. The algorithms and the system were also validated through WP5, by comparison to currently used, professional gait analysis systems.
The first important, integrated prototype delivered was the one used for mid-project experimentation. The Wi-Shoe insoles in these shoes included 19 sensors and an ECM v1 in each shoe. These prototypes were used also as a reference for experimenting on the use of cheaper, alternative force sensors. The calibration device and software, as well as the Lite App was also integrated in the approach.
Once a flexible version of the shoe cabling (FPC) became available, this was also integrated into the Wi-Shoe insole. The mechanical design defined the shape of the circuit and the exact position of sensors and was then translated in a circuit layout in which pads and copper traces were routed from each sensor to the end of a cable extension. The FPC v1 was designed to accommodate up to 19 sensors and to be compatible with the ECM v1. The integrated system (FPC v1 + ECM v1) was used for full tests in Cyprus, in order also to decide about the possibility to use cheaper sensors in selected positions. For these tests, a new, integrated prototype was developed. Different sensor technologies were combined in the same insole, in order to be able to directly compare their measurements. Since there is no ECM capable of measuring simultaneously more than 19 sensors, 2 ECMs were used on the same foot. The Podartis Teradiab shoe was used for these tests.
After the conclusion of the mid-project testing phase, several developments and upgrades were necessary, in order to be able to produce the final Wi-Shoe prototypes that were used in the field demonstrations. Those upgrades included:
- The upgrade of the ECM, in order to be able to read also cheaper sensors’ output.
- The final insole design, considering the final number of sensors used and their positioning.
- Better sensor versions.
- Various software upgrades.
The upgrade of the ECM was necessary for a) correcting all issues encountered with ECM v1, b) integrating the circuit for using also different, cheaper force sensors and c) reducing the size of the board. The ECM v2 was used in combination with both types of force sensors for various tests and it was then further improved in order to deliver the final, ECM v3. Regarding the upgrade of the Wi-Shoe insole, this was produces in accordance with the final selected sensor configuration. For the bottom layer, a new, improved material was used. New, upgraded sensors were also used. The FPC v2 was also produced, based on the final sensors configuration. Two FPCs were designed, one for the 41-43 size range and one for the 44-46 range. They are compatible with both the Activity and the Botero shoes. This approach reduced production cost. The FPCs can be manually trimmed to fit the actual shoe. The design of the FPC v2 is highly versatile. The Lite App, Calibration App and the Professional software were also upgraded, following the results of the mid-project testing. Regarding the final prototypes integration, the Botero and Activity shoes of sizes 41 to 46 were used.
An important task of this WP has also been the, so called, mid-project testing of the Wi-Shoe system. The scope of the mid-project testing was to test all initial project developments in an integrated way, in order to produce the final version of the Wi-Shoe system that was then used for actual validation tests. An important aspect of this testing phase was the definition of the final force sensors configuration inside the Wi-Shoe insole. Apart from the accurate force sensors that have always been considered as the backbone sensors of the Wi-Shoe insole, cheaper sensors have also been studied as a low cost alternative. During the mid-project testing phase, those sensors were further examined, both independently and in combination with actual Wi-Shoe electronics. Additionally, the FPC v1 has been used in combination with ECM v1, in order to verify its properties and deciding whether this approach can be viable also for the final system prototypes. Data collected during the mid-project testing phase were also used for an initial validation of the Wi-Shoe algorithms. Finally, the Wi-Shoe was also examined by the end-users from an ergonomics point of view, as an indication towards the development of the field prototypes.
The first experiments conducted were with the first integrated prototype that included 19 sensors. Those first, reference tests were conducted with the help of an adult male, wearing the no.46 prototype prepared. The acquired data were analysed, in order to measure the contribution of each sensor in the measurements. By examining all data collected during these experiments, it was noticed that usually force is mainly applied to specific parts of the insole. This was an information to consider regarding the possibility of completely removing those sensors (for cost reduction) or substituting them with lower cost sensors.
The next tests regarded the possibility of using cheaper force sensors. After testing the sensors independently and given the fact that those sensors are meant for use in a lower cost version of the system, it was concluded that their performance is acceptable. In principle though, those sensors should be used where forces are generally lower and contribute by a smaller percentage to the total VGRF.
Once the FPC v1 was delivered, this was also tested in combination with force sensors and ECM v1. Communication between the ECM and the Lite App was also tested during these tests. Through these experiments, FPC functionality was confirmed in real walking conditions. It was decided that the FPC approach will be used also in the final prototypes for the field demonstration. As a next step, the Teradiab prototype was tested with more accurate and lower accuracy (cheaper) sensors. As a conclusion, the use of low cost sensors was confirmed as possible for the Wi-Shoe lower cost version. The positions in which the Flexiforce sensors are used affects the system’s overall performance in different ways. In general, though, forces measured in specific insole positions were constantly very low, which meant that at least 2-3 sensors could be removed, in order to lower system cost, without affecting overall performance.
During the mid-project testing phase, comfort testing was made using also the help of volunteer patients of ANIMUS. All patients were recovering from a hip surgery. The results were not far from what was observed with the healthy volunteers (WP3). The results are normal and expected, not only because of the previous tests with healthy subjects, but also because the thickness of the Wi-Shoe insole used for mid-project validation was still not optimized.
The data acquired from the mid-project testing, but also from the early prototypes, were used for preliminary algorithms validation. Special attention was paid to the step detection algorithm, since practically almost all parameters depend on accurate step detection. Summarizing the results of this algorithms validation phase, all algorithms and formulas have been validated at least from a functionality point of view. Preliminary filtering of the data, for correcting the hysteresis effect of the force sensors, was also introduced after this phase.
After the delivery of the final Wi-Shoe prototype version, this was also fully tested through this WP, in order also to validate the system and algorithms. Ten adult volunteers participated in the experiments. The golden standard against which Wi-Shoe measurements were compared is the professional force-plates system available in CERTH. The Vicon motion capture system was also used to calculate step length and gait speed. Additionally, the Tekscan HR Mat was used to capture the person’s balance (force distribution between the two feet).
The volunteers where initially trained on the use of the Wi-Shoe system and were asked to wear the Wi-Shoe and familiarize with it. They were then asked to stand on the Tekscan HR Mat, in order to measure the pressure distribution between the two feet. They were also asked to stand with both feet on a force plate, in order to accurately measure their weight. Finally, the volunteers were asked to walk on the corridor, making sure that they would also step on a force place while walking normally. At least two steps with the right foot and two steps with the left foot where required, before concluding the test. During the whole test duration, the users would also wear the Wi-Shoe and data were contemporarily recorder by both the Wi-Shoe and the golden standard systems. Apart from collecting Wi-Shoe data and using them for the validation, the tests allowed also testing the communications between the Wi-Shoe, the Lite App and the Professional Software. During the tests, data was recorded using the Lite App and was transmitted to the Professional software, as it would normally happen in real conditions. No communication problems were detected. The Bluetooth connection between the Wi-Shoe and the Lite App can easily operate with no problems, even when the devices are about 10-meters apart. The validation tests allowed a direct comparison between the Wi-Shoe and the force plates measurements, especially in terms of VGRF, which is the main parameter on which several other calculations are based. Regarding weight measurement of all subjects, Wi-Shoe proved to be really accurate, as expected. Of course, the most interesting comparison was the one between dynamic measurements. The differences between the VGRF curve calculated using the Wi-Shoe and the ones calculated using the force plate were very small. The subjects’ weight distribution between the two feet, in a static position was also measured with the help of the Tekscan HR Mat system. This additional test was performed with 6 of the participating volunteers, as an additional verification system for Wi-Shoe performance. The subjects were asked to stand on the Mat in a comfortable position, wearing also the Wi-Shoe. As expected, based also on the force plates testing, Wi-Shoe performance in terms of static load measurement was excellent. As earlier stated, the Vicon motion capture system was used to calculate step length and gait speed. Wi-Shoe algorithms for gait speed and step length were also used with Wi-Shoe collected data. The calculation of those spatio-temporal parameters was not fully validated earlier, so these results were important for the full system validation. According to the obtained results the accuracy in measuring the spatio-temporal parameters is in the order of 1.5-3%. Moreover, collected data were also used to complete the algorithms validation. The step detection algorithm detected correctly all stance and balance phases.
The final Wi-Shoe prototype was also used for field testing with the help of the end-users. The system was used by both APOLLON and ANIMUS, in their own facilities. The prototype used for this testing was the one prepared and used also in the full-scale lab validations. The scope of this testing was to allow the end-users to familiarise with the Wi-Shoe and the mobile Application, as well as to help them with the use of the Professional software. The calibration device and App was also presented to them and they were asked to do a full calibration procedure by themselves. The whole experience was important for preparing the end-users for the demonstration phase.
In ANIMUS, after a short presentation of the Wi-Shoe system and App, the responsible doctor asked three patients, that had already provided their consent, to wear the shoes and move around the premises. The doctor was using the App to setup and start the acquisition. A questionnaire was then used to collect the feedback of both the doctor and the patients. A second doctor of ANIMUS was also asked to participate in the study, by simply using the Application and answering the questionnaire. Both doctors were generally capable of performing all the required operations. Regarding the patients, they were asked to evaluate the prototype from a comfort point of view, as previously done also for the mid-project testing prototype. The same questionnaire as before was used. The results, even though based on a very small sample of patients, are much better with respect to the mid-project testing. This was expected, since the prototype was significantly improved in terms of comfort, thickness and flexibility. Regarding the Professional software, the two ANIMUS doctors were introduced to its functionalities and were driven through the various screens. Specific comments were received regarding the possibility of changing various colours and texts in the interface. The calibration device and App were also introduced to the ANIMUS doctors. They were both asked to do a full calibration of one of the shoes, following the on-screen instructions. The procedure was found by both of them to be simple and intuitive.
Similar to the testing in ANIMUS, the system was also tested by APOLLON end-users in Cyprus, mainly in terms of comfort and software friendliness. CyRIC explained the use of the App to the club’s manager. Two athletes were also invited to wear the Wi-Shoe prototype and perform some basic training exercises, as well as walking. The team manager was using the App to setup and start the acquisition. A questionnaire was then used to collect the feedback of both the manager and the athletes. The manager found the Application very easy to use. Regarding the two athletes, they were asked to evaluate the prototype from a comfort point of view. The results are better with respect to the mid-project testing, even though a bit lower values were recorded, with respect to the answers of the ANIMUS patients. This is probably related to the fact that athletes are used to wear very comfortable, often custom-made, shoes while exercising. As in the ANIMUS case, the Professional software and the calibration device and App were also introduced to the club’s manager. Positive feedback was received.
WP6 - Demonstration of the Wi-Shoe system
WP6 dealt with system demonstration. The main objective was to demonstrate the system to the participating SMEs and end-users and to explain its functionality. The system was demonstrated with the help of the two end-users, ANIMUS and APOLLON. During the demonstration, all bugs encountered in the software were corrected.
Minor upgrades in the prototypes were required before actually starting the demonstration in both sites. The first improvement that was necessary was the integration of a miniature power off switch on the sole of both Wi-Shoe versions. Even though the power consumption of the Wi-Shoe has been significantly reduced with ECM v3, it was still more practical to have the possibility to completely deactivate the system when it is not used. This was especially useful for the demonstration phase. As a second improvement, wireless charging was also implemented in this final, field version of the Wi-Shoe prototypes. This was a feature planned since the project beginning, but it was impractical to integrate in previous versions of the prototypes. At this stage though, wireless charging was a significant advantage and simplified a lot the use of the system for the end-users. In order to charge the shoes’ battery, the user only has to turn them on (using the abovementioned switch) and place them on the charging pad.
Regarding the actual demonstration, the Wi-Shoe demonstration with rehabilitation patients took place in ANIMUS. Shoes of sizes 42-45 were available for this demonstration, based on the Botero model. In total, seven hip fracture and knee surgery patients participated in this demonstration. The demonstration consisted in a short training session, were the patient and his/her doctor were introduced to the Wi-Shoe and the way to use the shoes and software Application. Then, the patient would wear the shoes and normally walk in a straight line, in order to examine the VGRF curve data and verify that everything is working properly. At that point and, if the patient and doctor were confident to have understood the Wi-Shoe functionality, they were asked to do some data acquisition sessions and upload the data to the server (Professional software). In order to evaluate also the system’s friendliness, after those first tests, a pair of Wi-Shoes was given to the volunteers for using them by themselves for a week in their rooms. They were asked to do at least one session per day and upload the data on the server. After the test, they filled-in a questionnaire, with the help of the Wi-Shoe researchers, in order to get their feedback. The questionnaire covered both Wi-Shoe comfort and Lite App usability issues. The prototypes used, especially in terms of comfort, are identical to the ones used during the WP5 field tests. In fact, all seven volunteers found the shoes very comfortable. Regarding the Lite App friendliness evaluation, a significant improvement, also with respect to WP5 tests, was the fact that the Bluetooth pairing procedure, between the shoes and the mobile App was simplified. All users found the application very intuitive.
The Wi-Shoe was also evaluated with the help of professional athletes from the APOLLON women’s volleyball team. Shoes of sizes 41-43 were available for this demonstration, based on the Activity model (sports shoe). The demonstration consisted in a short training session, were the athletes were introduced to the Wi-Shoe and the way to use the shoes and software Application. Then, the athletes would wear the shoes and normally walk in a straight line, in order to examine the VGRF curve data and verify that everything is working properly. At that point and, if the athletes were confident to have understood the Wi-Shoe functionality, they were asked to do some data acquisition sessions and upload the data to the server (Professional software).
In order to evaluate also the system’s friendliness, after those first tests, a pair of Wi-Shoes was given to each of the two volunteers for using them by themselves for a month, during various activities (short walks, longer walks, running). Data were also collected during volleyball training sessions. They were then asked to upload the data on the server after each test. After the test, the athletes filled-in a questionnaire, with the help of the Wi-Shoe researchers, in order to get their feedback. The questionnaire covered both Wi-Shoe comfort and Lite App usability issues.
As in the ANIMUS case, the athletes were asked to evaluate the prototype’s comfort, as well as the friendliness of the Lite App. The shoes were generally found to be comfortable enough. The software was also judged as intuitive.
From the positive feedback received during the demonstration phase, as well as from the previous, full testing sessions of the Wi-Shoe system (D5.1) it is clear that the Wi-Shoe has achieved its goal of being an easy to use, non-intrusive system. Of course, specific things will be improved after the project, in order to produce the market version of the Wi-Shoe, including:
• Addition of an extra, soft layer over the other Wi-Shoe insole layers, in order to improve comfort
• Continuous improvement of the Lite App, especially in terms of simplification of the Bluetooth pairing procedure
• Improvement of the Professional software, especially in terms of automated advice and comments to the user and the expert
• Sensors permanently fixed in the insole, in order to increase robustness.
Data collected during the demonstration phase were also analysed for further algorithms improvement.
WP7 - Dissemination and Exploitation
The objectives of WP7 were mainly related to the dissemination of project results and the preparation for their exploitation. Additionally, through WP7, training of the SMEs was organised. The results of WP7 include the project website, the various publications, the project dissemination material (logo, brochures, presentations, posters, video), the dedicated workshop that was organised and, of course, the Interim and Final plans for use and dissemination of knowledge.
Regarding the training activities, their aim was to allow the commercial partners of the project to understand all details related to the Wi-Shoe production, assembly and use, as well as the science behind the algorithms. A training session was organised for the Wi-Shoe SMEs and end-users in ANIMUS premises. The training session included presentations by the researchers and a lot of interaction with the SMEs and end-users, in order to explain all details and respond to various questions. A live demonstration of the system was also organised.
Additionally, a “Manufacturing and assembly manual" was prepared, in order to facilitate results uptake by the SMEs. A “System operation manual" has also been prepared, describing the use of the Wi-Shoe Lite App and Professional software. Furthermore, a document was delivered, as an attachment to the operation manual, regarding the mathematical algorithms underlying the application software.
Regarding the project results dissemination, several activities took place. Dissemination activities included the project presentation in the following events:
• The 4th Biochemistry & Exercise Physiology conference, held on 24-26/10/2014 in Trikala, Greece by CERTH
• The Mechatronics, Integronics And Adaptronics - Smart Specialisation Conference, held on 13-15th of May 2015 in Bucharest, Romania by INCDMTM
• The International Neurology and rehabilitation Meeting (INeReM), held this year in Istanbul, TURKEY, in the period 4th - 6th of June by a poster prepared mainly by INCDMTM and CyRIC
• The icSPORTS 2015 congress, held in Lisbon, Portugal, during 15 - 17 November 2015 by CyRIC
Publications were also made in the following magazines/journals/newspapers:
• Horizon magazine, funded by the European Commission
• The Romanian Review Precision Mechanics, Optics & Mechatronics
• #DisruptCyprus electronic magazine
• “Erevna” newspaper, Greece
• “The Cyprus weekly” newspaper
Two different project brochures were prepared for use in the various dissemination activities. The first one was an initial project introduction. The second one was prepared for use in the latest dissemination events and presents more information. In order to present the project in an easy to comprehend way, also for the general audience, a video has also been prepared by CyRIC. The video is available on the website. A project presentation, open to the public, has also been prepared and has been made available through the Wi-Shoe website. It has been used for presenting the project to possible users of the technology (either through web-based seminars/discussions or through face to face meetings).
As a final dissemination event, a dedicated workshop was organised. The workshop was used to present the project results to various stakeholders and interested members of the general audience. Of course, researchers from the scientific community were invited and participated in the event.
Regarding the exploitation of project results, after an initial patent search, the SMEs proceeded with a detailed analysis of the patentability of the Wi-Shoe system. The exploitation plan was also developed. In principle, all four SMEs have co-ownership of all results that are of direct interest to them, based on their activities. A detailed business and marketing plan has been prepared by the SMEs, with the help of the RTDs and especially CyRIC. The targeted markets of Wi-Shoe are the Medical and Rehabilitation sectors –and more particularly the segments that use gait monitoring - and the Sports Sector. Because of the professional nature of the product, Wi-Shoe is targeting as potential customers hospitals & rehabilitation clinics, physiotherapists and sport medicine doctors rather than the end-users (patients and athletes) themselves. Initial focus will be on the European market. Nevertheless, the US and rest of the world markets will follow.
WP8 - Consortium Management
The scope of WP8 was to coordinate communication between partners and towards the commission and to make sure that the project reaches its objectives. IPR issues were also handled through this work package. Additionally, ethical issues and approvals were obtained through this WP, in order to be able to perform the system validation and demonstration with the help of the volunteers.
Regarding the exploitation of the project results, no changes were made to the initial Exploitation plan presented in the DoW and the Consortium Agreement which was acceptable by SME partners and includes all clauses with regards to Joint Ownership as stated within FP7/IP Guide.
All publications were first submitted to the Coordinator and IPR Manager for review. The Coordinator and IPR Manager also presented the publications to the SMEs for approval. In this way, no IPR sensitive issues were published.
Ethical aspects have also been dealt with through this task. Because of the need to involve volunteers, all ethical issues have been carefully examined. Informed consent forms have been developed for both end-user institutions and will be used with all subjects participating in the project as volunteers. Since the Wi-Shoe research is one of minimal risk, an approval from legal national bodies was not necessary. Nevertheless, the Ethics Committee of ANIMUS reviewed and approved the Protocol and Informed Consent Forms to be used by both organizations (ANIMUS and APOLLON) and issued the Ethical Clearance documents.
Regarding the project management, all objectives and milestones have been reached. Agendas, Minutes and Action plans for each meeting were prepared on-time and uploaded in the project management platform. Six consortium meetings have been organized since the project beginning (kick-off, 6M, 12M, 15M, 18M and 24M meetings). An Exploitation meeting also took place. Several Skype teleconferences have also been held for which minutes are available as well. A review meeting took place on M12 and was combined with the 12M consortium meeting.
Regarding communication management, the Coordinator has been in direct contact with the project officer either by email or phone and communicated when necessary to either get assistance or discuss any pending issues. For communication between partners the following tools were used: Skype, Email, Teleconference and the project management Platform Basecamp.
Potential Impact:
The targeted markets of Wi-Shoe are the Medical and Rehabilitation sectors –and more particularly the segments that use gait monitoring - and the Sports Sector. The list below, summarises possible user sub-categories for the Wi-Shoe system.
• Diabetic foot patients
• Patients suffering from: Lumbar spinal pains and bearing joints of the legs, Algofunctional Decompensated Gonarthrosis, Peripheral neuromotor lesions, Motor deficits due to paralysis of a hemi-body and central neuromotor diseases (e.g. stroke), Gait disorders related to ageing
• Patients recovering from fractures
• Patients suffering from lower limb osteoarthritis
• Patients recovering from hip/ knee/ ankle arthroplasty
• Parkinson’s disease patients
• Patients using a prosthesis
• Patients recovering from ankle/hip fusion surgery
• Patients affected by Pes cavus or Hallux Valgus
• Spinal cord injury recovering patients
• Patients suffering from fibromyalgia
• Completely healthy athletes for improving their performance
• Athletes recovering from injury through a gait rehabilitation/ training program.
Large amounts of money are spent every year for gait parameters and EE monitoring, but even so, it is not possible to use gait monitoring with all those patients for whom that would be beneficial. The fact that currently available systems require a controlled environment and an expert’s presence, in addition to the fact that their cost is several thousands of Euros, leads to their limited use. Adopting the Wi-Shoe solution which does not have any of these limitations, gait and energy expenditure analyses would be performed as often as required, in order to better assist patient recovery, earlier diseases diagnosis and sport performance improvement.
Wi-Shoe impact in the targeted sectors is multi-fold. Current cost for gait and EE monitoring is a large portion of the total cost of the rehabilitation procedure for patients requiring such monitoring. For professional athletes, it is an expense that only the richest clubs can afford. Firstly, the initial investment is high, since the cheapest gait monitoring system costs about 10.5k Euros and does not offer any EE monitoring possibility. A combination of this system with a professional EE monitoring system would require another 36k Euros. In addition, currently available systems and procedures require the subject to be at the hospital, clinic or training facility for the test. Furthermore, these gait monitoring systems require frequent calibration and the preparation for the test is quite laborious, since the subject has to wear all the necessary equipment. All these procedures lead to specialized personnel man hours spent for the system setup, calibration and control during the test. The use of the Wi-Shoe system is much simpler, since for the subject it is just a pair of shoes that he/she needs to wear.
The Wi-Shoe system does not require frequent calibration and most importantly, it can be used at home or wherever the subject prefers in everyday activities. The Wi-Shoe cost is expected to be significantly lower with respect to systems of comparable capabilities and accuracy and so it will be possible for the clinic or club to have several systems available for the subjects to use. Less time for the patient spent at the hospital, means lower cost for the clinic and the patient. Additionally, the subjects benefit from a continuous monitoring throughout their activities and not just during the few minutes at the hospital or training facility. Real-time monitoring means more data for the analysis, higher precision in the gait parameters calculation and increased possibility in detecting problematic situations that may not be detected during a conventional monitoring session.
Furthermore, the Wi-Shoe system allows remote monitoring of the subjects, without the need for continuous expert intervention. In this way, Wi-Shoe improves and supports the monitored subject’s sense of independence, which is of major psychological importance, especially in the case of elder people. The lack of cables running on the subject’s legs is of major importance for this advanced sense of independence. Increased sense of independence means better life quality as well. Because of the reduced number of clinic visits needed with the Wi-Shoe approach, the patient can spend more time at home, while simultaneously being monitored by an expert. In addition, the use of the Wi-Shoe system will allow resources optimization for clinics and hospitals, which has a direct impact on practically everybody. The doctors, for example, currently following patients during gait monitoring sessions, with Wi-Shoe will be available for other tasks inside the clinic. Thus, doctors or other experts will be used in more efficient way, reducing waiting.
In order to be able to quantify the potential impact of Wi-Shoe, focus was put on selected end-user categories: stoke patients, diabetes patients, the elderly and professional athletes.
Stroke is a common condition, especially for the elderly. The number of stroke patients in Europe is continuously raising and the annual cost becomes more and more difficult to deal with for patient families and for hospitals. After a stroke the patient needs continuous monitoring, treatment and help. Stroke patients are among the possible Wi-Shoe users, since they could benefit from the possibility to use the system at home, after release from the hospital. People that have suffered and survived a stroke in the EU are estimated at about 7.000.000. Additionally, 1.100.000 new stroke events are registered each year, with this number continuously raising, especially due to the growth of the over-65 population. The number of stroke events in Europe is projected to rise from 1.1 million to 1.5 million per year by 2025, largely due to the ageing population.
Another important subsector that is directly targeted by the Wi-Shoe system is the Diabetes patients sector and their monitoring. Diabetic patients often suffer from diabetic neuropathy. A patient suffering from this medical condition cannot feel parts of their body (dysesthesia) and most commonly the feet. Since the diabetics have dry skin that can very easily be wounded, if a patient during walking exercises more pressure to a foot then this area has a high probability of developing an open wound. Because of the dysesthesia, the patient will not be able to feel the wound and this can lead to extreme conditions, since diabetic patient wounds are very difficult to heal. Doctors usually ask patients to self-examine their feet every day in order to find possible open wounds and they will subscribe them special custom made boots that help them balance their weight distribution and thus avoiding further foot damage. Of course, clinics that have a gait monitoring system can examine the patient’s weight distribution before a bad distribution leads to the actual problem. Wi-Shoe in this case would be extremely useful because the medical team could detect in advance the incorrect weight (force) distribution and thus completely avoiding the problem. There are about 60 million people with diabetes in the European region, or about 10.3% of men and 9.6% of women aged 25 years and over. Prevalence of diabetes is increasing among all ages in the European region, mostly due to increases in overweight and obesity, unhealthy diet and physical inactivity.
Another area of high interest for Wi-Shoe is related to aging and elderly care. Aging leads to increases in gait variability which may explain the large incidence of falls in the elderly. Body weight support training may be utilized to improve gait and minimize falls. However, before initiating rehabilitation protocols, baseline studies are needed to identify the effect of body weight support on elderly gait variability. These can be made using the Wi-Shoe system. According to EUROSTAT, the proportion of the total European population older than 65 is set to increase from 16.1% in 2000 to 27.5% by 2050, while the proportion of the population aged over 80 years (3.6% in 2000) is expected to reach 10% by 2050. Thus, more than 100.000.000 people in the EU will belong to this category by 2020.
Regarding professional athletes in the EU and considering particularly data about football, basketball and volleyball players, those are about 690.000. The use of WI-Shoe for athletes will allow detecting problematic body posture conditions on time, thus leading to performance increase and less injuries. The fact that the athlete does not have to do anything particular, other than wearing the Wi-Shoe, facilitates the procedure and makes it possible for the teams to make the tests on the field, without having to visit a clinic. Additionally, the use of the Wi-Shoe can be very beneficial for recovering athletes. The Wi-Shoe can be used to monitor on a continuous basis the athlete’s applied weight distribution, balance and other important gait related parameters. This, combined with the athlete’s dedicated effort for quick recovery, can lead to an optimal recovery time. It is also important to highlight the benefits of Wi-Shoe for athletes that wish to improve their running efficiency. Any displacement that elevates, depresses or moves the centre of mass beyond normal maximum excursion limits wastes energy. Additionally, any abrupt or irregular movement will waste energy even when that movement does not exceed the normal maximum displacement limits of the centre of mass. A successful long-distance runner intuitively takes advantage of these principles. Wi-Shoe measures Centre of Mass (COM) vertical displacement, as well as Energy Expenditure, Gait speed, Stride frequency, Step length and other parameters, in order to provide the necessary information for avoiding waste of energy and improving running efficiency.
Wi-Shoe accomplished dissemination activities:
The project was presented in the following occasions:
• The 4th Biochemistry & Exercise Physiology conference, held on 24-26/10/2014 in Trikala, Greece by CERTH
The Wi-Shoe project and initial approach has been presented in the 4th Biochemistry and Exercise Physiology conference that was held on 2014 October 24-26 in Trikala, Greece. Dr Giannis Giakas of CERTH presented the paper.
• The Mechatronics, Integronics And Adaptronics - Smart Specialisation Conference, held on 13-15th of May 2015 in Bucharest, Romania by INCDMTM
The Wi-Shoe system was presented by Dr Mihai Margaritescu of INCDMTM in the MECHATRONICS, INTEGRONICS AND ADAPTRONICS - SMART SPECIALISATION Conference, that was held in Bucharest, Romania at the 13-15th of May 2015 in the ROMEXPO Exhibition Centre. It was an opportunity to present the Wi-Shoe project to researchers, to members of the Chamber of Commerce of Bucharest and to the general public
• The International Neurology and rehabilitation Meeting (INeReM), held this year in Istanbul, TURKEY, in the period 4th - 6th of June by a poster prepared mainly by INCDMTM and CyRIC
A Wi-Shoe short paper and a poster presentation has been accepted in the INeREM meeting in Istanbul. This has been a first opportunity to present the project approach and preliminary results in the medical sector. The International Neurology and rehabilitation Meeting (INeReM) was held in Istanbul, Turkey, in the period 4th - 6th of June 2015. Wi-Shoe consortium presented a poster. The abstract was also published in the proceedings.
• The icSPORTS 2015 congress, held in Lisbon, Portugal, during 15 - 17 November 2015 by CyRIC
The congress, held in Lisbon, Portugal, during 15 - 17 November 2015 was an excellent chance to present the Wi-Shoe applicability in the sports field to a very qualified audience to many possible system users. This was the last conference presentation during project lifetime and the most detailed one in terms of results that could be shared with the audience.
Both an oral presentation and a poster were used to present Wi-Shoe by Dr Alessandro Giusti from CyRIC. Wi-Shoe was also included in the conference proceedings and was listed in R&D sponsors of the conference
Publications were also made in the following magazines/journals/newspapers:
• Horizon magazine, funded by the European Commission
The Wi-Shoe project was one of the three EU-funded projects included in the article entitled "Wireless ‘smart trainers’ give real-time advice" in the Horizon Research & Innovation Magazine (http://horizon-magazine.eu/article/wireless-smart-trainers-give-real-time-advice_en.html).
• The Romanian Review Precision Mechanics, Optics & Mechatronics
An article on Wi-Shoe has been published in the journal towards the end of the project. The article is entitled: “Gait Parameters and Energy Expenditure Assessment with the novel wearable Wi-Shoe System”.
• #DisruptCyprus electronic magazine
An article regarding the completion of the Wi-Shoe validation phase has been published in the #DisruptCyprus electronic magazine and website (http://www.disruptcyprus.com/innovation/63-news-innovation/526-cyric-and-its-partners-develop-a-smart-wireless-shoe-insole-for-medical-and-sport-applications).
• “Erevna” newspaper, Greece
An article was published in the “H EREVNA” local Greek newspaper regarding the successful Wi-Shoe workshop that was organized towards the end of the project. The article is in Greek and targeted mainly the Thessaly community. Generic project information about the main results is also included in this publication.
• “The Cyprus weekly” newspaper
An article was also published at the English language, CYPRUS WEEKLY newspaper on December 2015.
Apart from the previous activities, two different project brochures were prepared. Those are available for download through the project website: http://www.wishoe.eu/index.php/results. A video has also been prepared by CyRIC and is available on the website.
As a final dissemination event, a dedicated workshop was organised. Presentations were made by all project RTDs, as well as by PMED, as a representative of the SMEs. The workshop took place on December 11th 2015 in Trikala, Greece. It was used to present the project results to various stakeholders and interested members of the general audience. Of course, researchers from the scientific community were invited and participated in the event.
Wi-Shoe results exploitation:
Because of the professional nature of the product, Wi-Shoe is targeting as potential customers hospitals & rehabilitation clinics, physiotherapists and sport medicine doctors rather than the end-users (patients and athletes) themselves.
A business plan has been prepared by the project SMEs, taking into consideration the costs associated to Wi-Shoe, such as production and manufacturing costs, operational expenses and marketing costs. Operational expenses cover Insurance, Accounting and Legal expenses as well as various other expenses such as utilities, equipment, service and maintenance. The main output of the financial analysis made, based on the Financial Indexes, is that Wi-Shoe is an efficient and very attractive investment.
The calibration device was also studied as an independent product. The scope of the calibration device is to provide the Wi-Shoe users with an easy way to check that the system sensors are working properly (within specifications) and also with a way of correcting the possible errors. The device could be sold as product but the SME partners have also considered the possibility of offering the calibration of the Wi-Shoe as a service.
The Exploitation Plan is in full accordance with the DoW and the Consortium Agreement was signed by all partners before the project start. There have been no recorded objections or apparent deviations by any partner against the Exploitation plan of the DoW.
List of Websites:
www.wishoe.eu
