Development of a Self-Powered Piezo-Resistive Smart Insole Equipped with Low-Power BLE Connectivity for Remote Gait Monitoring

• DOI: 10.3390/s21134539
• Publication Date: 2021-07-02T01:55:52Z
• Authors: Roberto de Fazio; Elisa Perrone; Ramiro Velázquez; Massimo De Vittorio; Paolo Visconti
• Keywords: Arduino; Piezoresistive effect

The evolution of low power electronics and the availability new smart materials are opening frontiers to develop wearable systems for medical applications, lifestyle monitoring, performance detection. This paper presents development realization a novel insole monitoring plantar pressure distribution gait parameters; indeed, it includes piezoresistive sensing matrix based on Velostat layer transducing applied into an electric signal. At first, accurate complete characterization Velostat-based sensors is reported as function sizes, support material, trend. testing low-cost reliable sandwich structure discussed. last interfaced with conditioning processing section Arduino Lilypad board analog multiplexer acquiring data. 3-axis capacitive accelerometer detecting parameters (swing time stance phase time) featuring walking. A Bluetooth Low Energy (BLE) 5.0 module included transmitting in real-time acquired data toward PC, tablet or smartphone, displaying them using custom Processing® application. Moreover, equipped piezoelectric harvesting scavenging energy from onfield tests indicate that walking speed higher than 1 ms−1, device’s requirements (i.e., P¯=5.84 mW) was fulfilled. However, more 9 days autonomy guaranteed by integrated 380-mAh Lipo battery total absence contributions section.