Diabetic Foot Ulcers.

What is a DFU?

Diabetic foot ulcers (DFUs) are a severe complication of diabetes mellitus (DM). They often result from lesions in the plantar tissue that can go unnoticed following the damage to the peripheral nervous system and subsequent loss of foot sensation, termed as diabetic peripheral neuropathy (DPN).

What impact do DFUs have?

According to the International Diabetes Federation (IDF), DM cases drastically rose in the past years, the number of adults affected by this disease reaching at least 463 million in 2019 compared to 108 million in 1980. Moreover, the number of cases is expected to reach 600 million by 2035.

DM currently affects 60 million European adults, half of which have developed DPN. It has been estimated around 50% of DPN patients will develop DFUs[1] in the following years, which can result in amputations 25% of the time with a 5-year mortality rate of 40%[2].

Costs of DFUs.

Diabetic foot complications not only affect the patient and their family's quality of life but also have a serious detrimental economic burden, specifically for those in low-income countries where the cost of treating a diabetic foot problem can be equivalent to 5.7 years of their annual income [6]. Current solutions focus on cure rather than prevention, involving frequent visits to the doctor for diabetic foot assessment which can be costly. The NHS in England has reported the total diabetic foot care cost to be around £935 million or £7,800 per patient for a year for a DFU and £16,900 per amputated wound [5].

The use of telemedicine to self-manage and ultimately prevent DFUs can, however, be extremely cost-effective [7] [8], due to the reduction in ulcer recurrences and fewer screening devices [7]. Taking this into account, Path Feel can provide a much-needed framework for effective management and prevention of DFUs [9].

Detection and Intervention.

Due to difficulty healing, amputations, and cost, the best solution for a DFU is prevention. Path Feel will revolutionize DFU prevalence through personalized medicine, integrated care, and diagnostics. Path Feel detects elevated plantar pressure and temperature and provides haptic feedback in response. This facilitates behavioral change through visual alerts, ultimately preventing DFUs whilst improving mobility. Real-time pressure and temperature data, and activity levels are analyzed through a smartphone application. This information is then passed on to healthcare professionals (HCPs) for review through a graded alarm system so that at-risk patients can be prioritized. This information is displayed on a sleek and easy-to-navigate online dashboard, called Path Insight. Thus, the proposed system is a self-monitoring tool that provides real-time personalized analysis on plantar pressure and temperature, activity levels, education, and haptic intervention to not only prevent foot ulceration but also reduce the need for frequent visits to the clinic.

Compliance.

Self-management of DM via remote monitoring of plantar temperature has shown to be efficacious in detecting future DFUs, therefore reducing its incidence. However, adherence to prevention practices through high patient compliance are pivotal in producing effective outcomes. Lavery et al. (2007) indicates compliance with temperature checking resulted in a reduction in DFUs, suggesting that incorporation of a regime involving self-monitoring of plantar temperature would empower self-management of condition; 80% of patients in the trial who developed DFUs did not adhere to the protocol[59]. Unfortunately, many DM patients are limited in assessing their foot conditions, especially whilst using dermal thermometers, as they have visual impairment, obesity or limited joint mobility (as reviewed in Lavery et al. 2007)[59]. Therefore, a telemedicine diagnostic tool such as Path Feel would be ideal. The use of a smartphone application alongside Path Feel can bridge the gap between patient behaviours and the healthcare system, and mitigate risk [55].

Conclusion.

DFUs are a devastating complication of diabetes, and early detection of ulcer development is vital in reducing further complications. Personalised alerts to both user and clinician will aim to ensure that appropriate action is taken to reduce DFU risk. Intervention is key to minimise DFU damage, and continuous pressure and temperature monitoring can implement this. Path Feel aims to aid DM patients take control of their foot care, and avoid the devastating effect a DFU can have on daily life.

The white paper aims to investigate even further the feasibility of using pressure and temperature measurements of the sole of the foot to predict formation of DFUs and the benefits of using Path Feel.