Single sensor, pressure and temperature mapping device for the prevention of diabetic foot re-ulceration

Abstract

The aim of this study was to develop and validate a single-sensor, in-shoe pressure and temperature measuring device. This PhD study, sought to determine whether the specifically designed and innovative, device is effective in reducing re-ulceration in a high-risk diabetic population, when compared with the local current standard diabetic foot care management. To date diabetic foot care management consists of relying on visual observation and clinical experience to detect signs of ulceration and later design an appropriate treatment plan. This study sought to establish whether this innovative device could be used as a cost-effective alternative to the standard costly in-shoe measurement systems which can be used in a clinical setting to evaluate pressure areas of interest at risk of ulceration. Furthermore, it sought to determine whether the orthoses currently prescribed are indeed offering the intended reduction of plantar pressure to prevent re-ulceration. The research comprised of 3 main phases. Phase one consisted of a detailed systematic review relating to the validity and reliability of in-shoe systems that are able to measure pressure and temperature simultaneously. It sought to identify studies that utilize in shoe pressure and temperature systems as an identification technique for peak plantar pressures and raised skin temperatures in the diabetic high-risk foot at risk of ulceration. It also consisted of 2 local scoping studies which explored the local biomechanical and offloading management of the diabetic high-risk foot. In the second phase, an innovative, single sensor pressure and temperature mapping measurement device was developed and validated against a commercial, gold standard, in-shoe system. This device was used to validate effectiveness of pressure reduction in previously ulcerated sites in the high-risk foot. Once attained, this device was expected to offer a low-cost and easy to use system to be used in a clinical setting. The third and final stage (Stage III) of this dissertation, comprised of recruiting participants living with type II diabetes mellitus with a history of ulceration and who had been prescribed standard hospital orthoses. These orthoses were assessed to determine whether they were reducing the peak plantar pressures by the recommended 30% reduction. Furthermore, this stage sought to develop a clinical protocol for the use of the innovative, single sensor temperature and pressure mapping device to possibly replace the current expensive and time-consuming commercial in-shoe pressure and temperature measuring devices. Findings of this PhD research highlighted that the biomechanical management of the high-risk diabetic foot consists of simple assessment of pedal range of motion and foot deformities. Furthermore, technology to assist the clinician in determining the effectiveness of prescribed offloading devices, through identification of in-shoe peak plantar pressures, in view of ulcer and re-ulceration prevention, is not available in local health care services. Results further showed that local clinicians deem the use of such technology as too expensive and time consuming to use in their busy clinical schedule and thus, clinicians tend to base their treatment plan on clinical experience and visual observation. Quality assessment of 17 studies relating to the validity and reliability of in-shoe pressure and in-shoe temperature devices being developed in view of diabetic foot ulcer prevention, demonstrated low quality of evidence. This highlighted the need for further improvement, reliability testing and clinical validations of in-shoe pressure and in-shoe temperature measuring devices. An innovative, single sensor, in-shoe pressure and temperature measuring device, that is able to read pressure and temperature simultaneously, was developed and validated, on healthy participants, under both static and dynamic laboratory conditions. Results of both the static and dynamic validation studies showed high correlation results between the innovative device and the FScan® and Flir® thermal camera which served as reference standard for in-shoe pressure assessment and temperature assessment respectively. Lastly, clinical validation of the innovative, single sensor, in-shoe pressure and temperature measuring device, was confirmed in a clinical trial that involved the diabetic high-risk population. Results of the clinical trial demonstrated that participants who were monitored for peak plantar pressures and skin temperature with the innovative, single sensor, in-shoe pressure and temperature measuring device together with receiving the current standard diabetic foot care management, fared better in terms of presenting with less cases of re-ulceration, compared to the control group who only received the current standard diabetic foot care management. These results highlight the need for change and improvement in the current diabetic foot care management plan if better outcomes in terms of ulceration and re-ulceration prevention are to be attained. The introduction of diagnostic technology in clinical care, such as the innovative, single sensor, in-shoe pressure and temperature device, to monitor in-shoe plantar pressures and in-shoe temperature of the diabetic high-risk foot, is expected to bring about a change in the way that both patients and health care system could holistically benefit.