Novel plantar pressure measurement protocol and design of machine learning based sensorized shoe for special diabetic footwear

Diabetes is a chronic condition characterized by elevated blood glucose levels, resulting from insufficient insulin production or ineffective insulin utilization. According to the World Health Organization (WHO), the prevalence of diabetes mellitus is steadily increasing, and in 2021, with 6.7 million deaths, it ranked as the ninth leading cause of global mortality. Diabetes is also responsible for approximately 60% of non-traumatic lower limb amputations, mainly due to infectious ulcerative events in the foot known as diabetic foot, linked to both vascular and sensory and motor neuropathy complications, typical peripheral complications of the condition, exacerbated by concurrent traumas. Diabetic foot ulcers represent a widespread and serious consequence of long-term and poorly managed diabetes. Among the approximately 537 million individuals worldwide with diabetes, 19% to 34% will develop an ulceration during their lifetime. Notably, around 20% of those developing an ulceration may require lower-extremity amputation, either minor or major, and 10% are at risk of mortality within one year of the initial diagnosis of diabetic foot ulcer. A significant mechanical factor contributing to diabetic foot is increased plantar pressure, often resulting from unnoticed mechanical trauma and altered lower extremity mechanics. The most common site for foot lesions and ulcers in diabetic foot is the plantar region of the metatarsal heads where pressure is highest. The use of appropriate footwear among diabetics and those with diabetic foot problems has been well documented to play a vital role in the prevention and treatment of established foot disease. The aim of this thesis is to develop technologies supporting the preventive phase of the disease by qualifying footwears that manages better the diabetic foot and prevents its development. Additionally, it aims to provide indicators through wearable technology that allow careful monitoring of the progression of the pathology. A wide experimental campaign of plantar pressure measurements was conducted, highlighting how mechanical characteristics of footwear influence plantar pressure values. Footwears with different sole rigidities were considered, and it was found that shoes with mechanically stiff properties help to develop lower plantar pressures than those with more flexible soles. This was possible to highlight with an innovative measurement protocol and an analysis that takes into account walking speed and the subject's body mass index. Furthermore, a prototype of a wearable device that assesses the main parameters of walking and the physical condition of the subject has been developed, aiding in the management and progression of the disease.