European Commission logo
English English
CORDIS - EU research results

Medical remote monitoring of clothes (MERMOTH)

Final Report Summary - MERMOTH (Medical remote monitoring of clothes)

The demand for portable monitors has drastically increased, thanks to miniaturised technologies. On the other hand, overspending due to increasing demands from ageing demographics has caused European governments to impose spending cuts in the healthcare sector.

The continuous remote monitoring of some vital signals from patients is a new health care concept. It aims at providing the clinical study markets and academic laboratories with instrumented clothes that can monitor patient's health. In that research project, the design of the fabric is one of the most critical issues, since it could be manufactured as a woven, or a knitted product. Since comfort is an important parameter for a 24-hour a day monitoring, the design of the fabric appears to be a key for the positioning of the sensors and the actuators within the final product.

The main objective of MERMOTH was to develop a comfortable, wearable monitoring unit, which will be based on a 'wearable interface':
- it is implemented by integrated smart sensors, advanced signal processing techniques and new telecommunication systems on a textile platform.
- a parallel data management will be designed and tested in order to provide the first two markets with a whole prototype unit for extensive testing.

The outcomes of MERMOTH are presented by:
- a product: wearable equipment for the first two emerging markets (academic research, chemical drug trials);
- a service: a monitoring service for the second application and, possibly, a renting service for both applications where a dedicated company is in charge of the manufacturing.
The added value of MERMOTH are clearly greater when seen as an integrated whole, especially for the clinical trials of drugs.

As an alternative for conventional gel electrodes, knitted stainless steel electrodes were developed by the consortium for the measurement of ECG. The advantage of such ECG electrodes is their non-irritating character (in contrast to the gel electrodes) and the possibility of integration in a cloth. Three ECG electrodes have been knitted in the suit during the knitting process. Two electrodes are used for the measurement itself and the last one as reference electrode.

The use of six or seven pattern bars in a crochet machine allows transferring easily conductive yarns from left to right and from bottom to the top of fabrics without interruption. This technology was considered as the first technology to be tested in the frame of the respiratory sensor. The new sensor is made of a copper yarn, crocheted in a polyester belt, providing an adjustable stretch due to the addition of rubber yarns. The conductive yarns will form a sinusoid. The width and the height of the sinusoid are optimised in order to detect easily short variation of conductivity.

The raw signal from the sensors is pre-processed in the garment and/or in the PDA: The pre-processed digital data is transferred from the garment to a mobile receiver. For the prototype development, it was chosen to link a PDA to the garment via a wire connection.

The data transfer from the PDA to the PC platform is via a short range RF link. This means allows to have a real time transfer or to download the data after the end of the recording session. Moreover, the patient or his environment may use the PDA as an event marking recorder.

The modules for power consumption optimisation, communication and data pre-processing have been tested. In the frame of the project, all the technology is based on commercial systems, with the autonomy suited to the system needs. It ensures:
- medical signal acquisition, and possibly event detection;
- information and communication management;
- power consumption: apart from chasing for power savings, a specific management unit is developed to reduce energy consumption;
- miniaturisation: all technology choices are addressed to maximise the potential reduction of circuit size and costs.

Some tests were performed to compare the metrological aspects of the MERMOTH sensors to a reference medical Monitor. The 'gold standard' which was used is a Datascope Passport 2. In these comparison tests, the patient is equipped with the MERMOTH garment and with the original sensors of Datascope: sticking ECG electrodes, 'Respiratory impedence plethysmograph' (RIP) and skin temperature.
The MERMOTH system has been tested on a wide variety of patients: age, sex, size.
It proved to collect and process pertinent and accurate physiological data in various situations: at rest, walking, running.

The results were:
- the sensors and the whole MERMOTH system deliver valuable and easy to read information on the patient's physiological data and behaviour;
- the ergonomic aspects are appreciated by the patients, it is comfortable to wear during several hours; the total duration of tests on patients reaches nearly 22 hours;
- the stretch qualities of the garment allow dressing people in a range of 2 or 3 sizes with the same garment;
- it is washable and easy to maintain.

The innovation within the MERMOTH project was in 3 directions:
- the architecture of a wearable health care system, which consists of the fabric, the switchboxes, including electrodes and the wiring and their respective organisation within a suit to meet comfort objectives and quality of the collected signals within at least a 24-hour full autonomy for the patient.
- the power distribution, which is dependent of the type of sensors implemented 'on board'. The data which are gathered on body temperature, ECG signals, blood pressure, breathe frequencies, acceleration for the monitoring of falls lead to a quantity of data processed per day which in turn leads to an autonomous life time which may vary over the day.
- the industrial aspects, of the new services provided by this intelligent suit being ubiquitous (availability of date, anywhere, anyhow), being user friendly (can -fit several types of patients), being cost acceptable (meaning a minimal cost of ownership, investment, operation and maintenance costs) which in turn lead to manufacturing costs as a function of the produced volume of smart suit per year.