Wearable Foot Pressure Sensing System for Fallen Arch Analysis

Abstract

The main purpose of this research is to distinguish the extent of fallen arch by analyzing the center of foot pressure when people are walking. Fallen arch is often called the flatfoot. There are two types of flatfoot, the rigid flatfoot and the acquired flatfoot. The rigid flatfoot is because of bones formation, and people often get rigid flatfoot when they are young. The acquired flatfoot occurs usually on adults because of the walking postures, shoe types, weight and so on. Since these reasons, it is possible that we can improve or prevent the acquired flatfoot through wearing orthotic insoles or changing the walking posture. That’s the reason why our research is focusing on the acquired flatfoot. In this research, we develop a wearable foot pressure sensing system, consist of wireless Bluetooth transmit module and sensing insoles. The wireless Bluetooth transmit module helps to accomplish our measuring system as a wearable device. The sampling rate of wireless Bluetooth transmit module is one thousand samples per second. As a result, we can get a very detailed track on the walking motions. The sensing insoles are made of triboelectric nanogenerator (TENG) technology. The working principle of TENG is based on the coupling of triboelectric effect and electrostatic induction. Depending on the property of triboelectric generation of different materials and through continuous contact and separation, there is an electrostatic induction and current flow between the triboelectric layers and the electrodes, thus causing the potential difference. By detecting the potential differences, we can get the signals of pressure, so we can calculate the center of foot pressure and compare with the standard to check which walking posture we can apply to improve the fallen arch and find out where the center of foot pressure should be placed. Using this system, we can get the real-time foot pressure information and collect the information anytime and anywhere, accomplishing the smart medical.