Characterizing an Exoskeleton Device for Human Leg Muscle Rehabilitation
Publication Date
1-1-2023
Document Type
Conference Proceeding
Publication Title
2023 29th International Conference on Mechatronics and Machine Vision in Practice, M2VIP 2023
DOI
10.1109/M2VIP58386.2023.10413386
Abstract
Stroke patients often suffer from disabilities and are unable to walk freely. This project was initiated to design and develop an exoskeleton device for leg muscle rehabilitation, without any external human assistance, at San Jose State University. The initial device, called Assistive Bionic Joint (ABJ), consists of movable brackets designed to be mounted on the patient's leg, around the knee, incorporating four fluidic muscles (two are mounted on the thighs and the remaining two on the calves). A few limitations were identified, and in the second design, additional fluidic muscles solely around the thigh were incorporated to increase the range of the ABJ. In the current project, the previous setup is further improved by redesigning the top part of the bracket that utilizes five fluidic muscles to minimize the reaction and operation time of the device. The central control system is based on a microcontroller (Arduino Uno) which receives input signals from EMG sensors on the patient's leg. The EMG sensors are activated by electrical impulses of the muscle's movement when the patient intends to move. These noisy signals require further processing to achieve a high signal-To-noise ratio and activate the central control system. A control box was designed to house the Arduino-based circuit. The system implements a relay capable of electrically controlling the current flow to the actuators (assisted by solenoids) responsible for determining the airflow direction. The calibration of the rotary encoder mounted at the joint of the two brackets of the exoskeleton was accomplished to obtain correct results on the brace rotation velocity and displacement. EMG sensors were found sensitive to the mounting positions along the leg muscles. The new ABJ design gave an improved time of operation as compared to design 1 and design 2 (1.773 seconds vs 3.673/3.164 seconds) and made for an increased range of displacement (36.5 degrees). The following sections include details on this project's various design and experimental aspects.
Keywords
assistive joint, exoskeleton device, rehabilitation, sensors
Department
Mechanical Engineering
Recommended Citation
Sahana Chowlur, Rishit Agrawal, Sohail H. Zaidi, and Vimal Viswanathan. "Characterizing an Exoskeleton Device for Human Leg Muscle Rehabilitation" 2023 29th International Conference on Mechatronics and Machine Vision in Practice, M2VIP 2023 (2023). https://doi.org/10.1109/M2VIP58386.2023.10413386
