Wearable Organic Integrated Sensors for Healthcare: Smart Dressings, A Step Change in Wound Management

Chronic wounds are those that fail to heal in an orderly and timely (typically three months) manner. Examples of chronic wounds include diabetic foot ulcers, pressure ulcers and venous leg ulcers. The incidence of chronic wounds is increasing as a result of lifestyle changes and the ageing population. For example, ~552 million people worldwide are estimated to have diabetes mellitus in 2030. Up to an estimated 25% of these patients will develop diabetic foot ulcers in their lifetime; half of these ulcers will be infected and 20% will undergo amputation of their lower limb. The annual economic impact of chronic wounds, which includes nursing time and dressing materials, on the global economy is estimated to be ~£20 billion by 2030.

A common practise in wound management is to cover wounds with suitable dressings to facilitate the healing process. Standard dressings, however, do not provide insights into the status of the wound underneath. Thus, dressings are often changed to examine and assess the wound. This in turn hampers the process of normal wound healing and cause stress and pain to patients. The assessment process also consumes a significant amount of nursing time and dressing materials, which contributes to spiralling medical costs in wound care. In addition, current treatment methods do not use physical or chemical feedback to modify or adjust the treatment based on wound's condition, and hence have limited success.

It has been proposed to embed sensors in dressings to enable clinicians and nurses to make effective diagnostic and therapeutic wound management decisions without changing wound dressings; therefore improving patient comfort. Existing sensors, however, do not satisfy the operational (e.g. sensitivity, specificity) and physical (e.g. flexibility) characteristics required for embedding them in dressings. This project will develop a sensor system to overcome these limitations.

The proposed sensor system will consist of a small laser that will emit light of different colour based on the concentration of a biomarker of interest in the fluid interface at the wound surface. The change in the colour of emitted light will be measured by waving a mobile device (e.g. phone, tablet) over the dressing containing the sensor system. The captured data will be transmitted to healthcare professionals, processed, stored to keep a record of wound history, and used for diagnostics and therapeutics.

The proposed project will benefit patients by effective diagnostics and treatment of chronic wounds. The information on wound condition will permit timely identification of hard to heal wounds and will also be used to create a feedback loop for fully optimised treatments tailored to individual patients. For example, the rate of release of anti-inflammatory drugs will be tailored based on wound condition. This is critical in terms of chronic wound management, where it has been shown that the longer the delay in administering appropriate treatment, the more difficult a wound is to heal.

The project will contribute towards scientific advances in 'Disruptive Technologies for Sensing and Analysis', 'Advanced Materials', 'Future Manufacturing Technologies' and 'Medical Device Design and Innovation'. The field of 'Disruptive Technologies for Sensing and Analysis' will advance because the proposal will result in highly sensitive, specific, flexible, integrated and robust sensors. The small footprint of photonic crystal sensors also implies that multianalyte arrays can be embedded in dressings to permit multiplexed and high resolution imaging of biomarkers in wound exudate. The proposal will find new applications of 2D- and nano-materials in sensors and hence progress the field of 'Advanced Materials'. The proposal will advance 'Manufacturing Technologies' by developing integrated nano-, micro- and macro-manufacturing techniques (such as self-assembly) to realise sensors that are mass producible. The proposal will result in dressings with embedded sensors that will permit monitoring and personalised treatment of chronic wounds.

Exploitation of the developed research will be pursued; any patentable IP will be protected through the University based Knowledge-Exchange team. Results from the sensors embedded in wound dressings during this project will form the basis of further funding applications towards a commercial product for example via 'Horizon 2020', 'NIHR's i2i Programme' and 'Innovate UK Grants' with industrial collaborators. Ultimately, the most likely commercialisation route will be through licensing to an established wound management company (e.g. Smith and Nephew). The commercialisation and exploitation of proposed sensor system embedded in dressings will lead to economic benefits to wound management companies.

The project will train two PDRAs in conducting world class academic research in an interdisciplinary research topic. Another key impact of the project is, therefore, to produce highly trained and versatile personnel who will be able to contribute to the UK and global knowledge based economy. The project will permit the investigator to embark on her ambitious programme of research on revolutionary sensor systems for healthcare, accelerate her career trajectory and position her as a leader in this area.

The sensors developed during the proposed programme will benefit patients suffering from chronic wounds who will receive treatments that are not only timely, but is also personalised and where possible patient delivered. This in turn will result in improved healing of wounds, enhanced patient quality of life and reduced care delivery costs. The information provided by the proposed sensor system on wound condition without changing dressings implies that nursing and clinicians' time will be reduced. This is in addition to a decrease in the overall cost of dressing materials. The rapid healing of wounds will also reduce number of hospitalisations, which are currently required to treat infected wounds. The ultimate efficacy of dressings with proposed sensor system in facilitating wound healing will result in reduced wound management costs.