Evaluation of Humidity FBG Sensors for Diabetic Foot Monitoring

Abstract

Complications affecting the lower limbs are considered as the most common debilitating manifestations of Type 2 Diabetes (T2D), accounting for significant preventable morbidity and mortality by predisposing the foot to neuropathy, infections, and ulcerations, which could lead to lower extremity amputations. Effective management of the diabetic foot (DF) is critical to prevent the formation of ulcers, as the disease increases their susceptibility to infection, due to compromised/impaired sweat gland function causing dry, crack-prone skin. This study presents the design and development of novel humidity sensors for diabetic foot care, using Fiber Bragg Grating (FBG) sensors. To determine optimal suitability for insole incorporation, the sensors were integrated into various materials, including Dragon skin 10 and agar/chitosan mixtures at concentrations of 1:1, 1:3, and 3:1, respectively to evaluate sensitivity and responsiveness/recovery characteristics to humidity changes. Experimental findings demonstrated that agar/chitosan mixtures at 1:3 and 1:1 concentration are optimal for monitoring humidity changes due to their rapid response and recovery. This underscores the potential of these sensors to enhance wound management in the DF by improving moisture control, hence aiding in accelerating the healing processes toward the prevention of limb loss.

Keywords: Humidity Sensors, Biomedical Sensors, Skin Hydration, Diabetic Foot.