The Use of Custom-Made Pressure Sensor-Equipped Footpad for Lower Extremity Lymphedema Patient

Abstract

The arch plays the role of buffering the impact and stress caused by the body. Flat-footed people do not have a normal arch when standing or walking, due to the tissues holding the joints in the foot together (called tendons) are loose. Injuries may occur as no arch to reduce the impact force, as their foot has complete or near-complete contact with the ground. Lymphedema patient have arch collapse. The purpose of this study was to explore the effect of using textures and arch insoles on improving the pressure distribution and balance of patient. The aim of this study is to develop an intelligent system that integrates current modern technology to analyze the plantar pressure of patient, to investigate the changes of plantar pressure with different motions, and finally to investigate patient' plantar pressure under different situations. Our ultimate goal is to develop a customized plantar pressure system for different people, time, and needs. When the occurrence of an unexpected event, the system can detect and report it immediately, allowing caregivers to act on time so to minimize harmful effects. The contribution of this study may also be suited for people with different special needs (e.g., stroke, flatfoot, dementia, and lack of mobility at walking). A commercially available foot pressure analysis system could cost from 10,000 to 20,000 and is therefore an unaffordable private device for lymphedema patient . In this study, the cost of self-made plantar sense of foot shoes costs only a few hundred dollars. Under the supervision of the physician, self-made foot test insole according to patient foot shape and plantar pressure distribution will be made for patient through a 3-D printer. The goal is to balance the plantar foot pressure by alleviating excessive foot pressure that might lead to foot lesions or nerve and musculoskeletal damage, which may reduce the occurrence of ulceration and subsequent amputation risk. To collect the data of human plantar pressure data, for each foot, six piezoresistive force sensors were embedded into an insole (12 sensors for both feet). These sensors were linked with an Arduino, a family of single-board microcontrollers, was used to input, process, and output data between the piezoresistive force sensors and the computer. A 3D printer was used to generate different shapes of an insole (Textured insole and arch insole) to investigate the effect of the shapes on plantar pressure. The study has been approved by the IRB (The Institutional Review Board / Ethics Committee) on National Taiwan University Hospital (IRB Case Number: 201805068RIN).