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Miniaturized smart system for light stimulation and monitoring of wound healing

Periodic Reporting for period 1 - MEDILIGHT (Miniaturized smart system for light stimulation and monitoring of wound healing)

Reporting period: 2015-02-01 to 2016-07-31

Chronic wounds represent a significant burden to patients, health care professionals and health care systems affecting over 40 million patients and creating costs of approximately 40 billion € annually. The goal of the project is fabrication of a medical device for professional chronic wound care. The primary application areas for the MEDILIGHT device will be diabetic foot ulcers (DFU) and venous leg ulcers (VLU). The uniqueness of the MEDILIGHT device in the market lies in the fact that it will also fight infections very likely present in chronic wounds in addition to its anticipated effect on the various healing stages of cleansing, granulation and epidermisation. The MEDILIGHT device, based on photobiomodulation principles, will use recently proven therapeutic effects of visible light to enhance the self-healing process and monitor the status and history of the wound during therapy. Light exposure in the red part of the spectrum (620-750nm) induces proliferation of keratinocytes and fibroblasts in deeper layers of the skin. The blue part of the spectrum (450–495nm) is known to have antibacterial, anti-inflammatory effects predominantly acting at the surface layers of the skin. In order to be compliant with hygiene requirements the system will consist of two parts: 1. a wound dressing with blue and red LEDs integrated into that and co-integrated temperature and oximetry sensors. These sensors will monitor the temperature and the blood oxygen at the wound area, thereby providing vital information on the current status of the healing process. The sensor data will be interfaced/communicated to a smart platform equipped with URGO’s expert system in order to be evaluated and loop back an individualized light therapy for the patient. The photonic and sensor part of the dressing will be detachable and re-usable and only the wound dressing itself will be disposable. 2. a flexible and compliant electronic module for multiple use containing a microcontroller, data processing unit, a rechargeable battery and a data transmission unit. The electronic module will be re-usable and optimized for functionality and user comfort, taking into account the type of patient disease (DFU or VLU), the wound size and localization. Furthermore, the electronic module will be manufactured with conventional, high MRL surface mount PCB assembly processes. The detailed effects of separate blue and red irradiations will be deeply investigated and light-exposure schemes will be developed and will be backed by in-vitro and in-vivo animal studies. Results will be used to develop smart algorithms and implement those into respective programs in an expert platform which will loop feedback back to the photonic band aid device.
The work performed from M1-18 is split thematically into the work packages and covers both the workplan defined to the initially proposed technology approach followed up to M12 and the modified plan followed after M12 as described in the approved techical amendment.

WP1 - Requirements and specifications
Definition of patient and users need in advanced wound care
- Diabetic foot ulcers as priority 1
- Venous leg ulcers as priority 2
Quantitative and qualitative requirement and specifications
- Treatment efficiency on wound healing and bacteria
- Safety, autonomy and no pain for the patient
- Compatible with offloading boots and/or compression therapy bandages

WP2 - Optical Elements and Sensors
Research on highly transparent, mechanically flexible and cost-effective plastic waveguides
Design, fabrication and optimization of incoupling nanostructures for large area waveguides
Design, fabrication and testing of homogenizing outcoupling microstructures
Fabrication of flexible large area waveguides with in- and homogenizing outcoupling structures
Design, printing and testing of temperature sensors on flexible plastic films (waveguides)
Research on nanoporous layers as optical claddings for large area flexible waveguides
Development of two alternative illumination concepts (fibers and LED foil)
Research on suitable LEDs
Development of various LED board designs (optical domain)
Proposal of different diffusor designs
Measuring of optical power and light distribution of all possible candidates
Measuring of optical power and light distribution of the final assembly with wound dressing
Optimization for best possible optical efficiency and illumination homogeneity
Simulations and optimizations on prismatic diffusors
Delivery of two illumination system designs with and without spacer between LEDs and diffusor

WP3-Electronic Module design, miniaturization, fabrication, and encasement
A. Connector development (initial waveguide approach)
Mechanical fixture to clamp the waveguide as well as the waveguide for the printed electronics
Fixed in-coupling alignment
- Connector element developed and presented at M9

B. Electronic module development (digital unit)
Electronic system concept developed
Suitable components and evaluation board selected for the development
Breadboards designed and fabricated
System concept evaluated and validated
- Main board presented and functionality demonstrated
- RS232 Driver breadboard designed, fabricated and functionality demonstrated
- Digital temperature sensor breadboard designed, fabricated and functionality demonstrated
- Digital photo sensor breadboard designed, fabricated and functionality demonstrated
- Pulse Oximeter breadboard designed, fabricated and functionality demonstrated
- LED driver module (Des577R1 - for waveguide approach) breadboard designed, fabricated and functionality demonstrated

C. Illumination system development
Concept for the illumination system developed
Suitable components selected
Various breadboards designed, fabricated and tested
Illumination system concept evaluated and validated
- Des602R1 breadboard designed, fabricated and tested
- Des602R2 breadboard designed, fabricated and tested
- Des602R3 breadboard designed, fabricated and tested
- Des602R4 breadboard designed, fabricated and tested
- Des602R5 breadboard designed, fabricated and tested
- Des602R6 breadboard designed, fabricated and tested
- 50 LEDs driving capability test breadboard designed, fabricated and tested
- LED driver test breadboard designed, fabricated and tested

WP4 - Data processing and light stimulation scheme
A. Test Application Software
Software drivers and associated test applications have been developed for the various sensors and protocols used on the MEDILIGHT system.
A demo application has also been developed for the microcontroller and also for a PC to interactively control the intensity of the red and blue LEDs, monitor the
The results acquired in the project so far are in line with the ambitious goals to develop a smart photonic band aid and therefore advance the state-of-the-art in the therapy of chronic wounds in a remarkable extent. Without the use of light therapy, the SOTA suggests the use of pharmaceuticals (local and systemic antibiotics) and wound dressing in contact with the wound, of course without any intelligence inside. With the use of light therapy, very bulky stationary therapeutic equipment is used with a size of 50cmx50cmx80cm only in hospitals by expert personnel to evaluate the progress of healing. Other photodynamic methods are based on the use of gels and their therapeutic actions under light interactions. The Bluetouch product from Philips (Blue LED light) is recommended for back pain release and is not appropriate for wounds. Also it has been tried against psoriasis. The MEDILIGHT product, after the change of the technical approach, is built on a foil with assembled LEDs which in turn will be integrated directly in the wound dressing. Patents will be applied for the wound dressing designs. Its therapeutic effect underlies on the photobiomodulatory effect of blue and red visible light on chronic wounds. In comparison with other products in the market, it strives to make a significant differentiation in the market by addressing all healing stages for chronic wounds including the cases of severe infections that may be present by wounds. The intelligence added in such photonic band aids will contribute very positively to the flexibility of personal care. The socio-economical impact of MEDILIGHT product for the treatment of chronic wounds remains very high.