Wearable wireless inertial sensors for estimation of gait parameters and its integration with portable harness ambulatory system for rehabilitation

There is a growing demand for quantifying the performance and efficacy of rehabilitation programs. Researchers are advocating home based rehabilitation devices and continuous monitoring of patients status in real time through wearable sensors. This paper investigates the use of inertial measurement sensors for recording the dynamic gait status. In order to facilitate long term recording and minimal interface of recording devices, these MEMS sensors are advantageous in many ways over the conventional laboratory methods. Portable Harness Ambulatory System (PHAS) can be effectively used in home environments with minimal assistance for gait rehabilitation. This paper addresses the stages of mechatronic integration of a prototype of PHAS with an aim for early gait rehabilitation of elderly and stroke survivors without fear of falling. Sensors modules comprised of accelerometer and gyroscope were developed. X-bee wireless communication protocol is used for transmitting the gait data for computer storage. Gait experiments with wireless sensor modules attached to shoulder, wrist, thigh and ankle joints of normal human subjects were conducted for slow and fast walking speed. The inertial measurement sensors provide information on the range of motion, gait speed, and orientation. Experimental results prove that sensor modules were successfully able to acquire and record the gait information wirelessly. These sensor modules can also be integrated in the PHAS prototype. The paper outlines the results of initial research and discusses possible alternatives.