Utilisation de signaux électromyographiques pour le contrôle d'un bras robotique pour les usagers de fauteuils roulants motorisés

Abstract

High level spinal cord injury individuals do not have the capacity to use their arms, but they still have a control of several muscles depending on the level of injury. The Canadian corporation Kinova has developped a 7 degrees of freedom robotic arm, JACO, meant to be mounted on a motorised wheelchair in order to help spinal cord injury victims in their everyday’s life. JACO can be used to grab objects or open doors only using a simple joystick. However, some poeople don’t have enough musclar capacities to use this joystick, and therefore, can not use the robotics arm. The goal of this project is to adapt the use of JACO to spinal cord injury individuals using electromyographic (EMG) signals from four muscles of the neck and shoulders. EMG signal acquisition is performed using preamplified and filtered Delsys electrodes in real time at a sampling frequency of 2KHz. These electrodes are placed on 4 muscles : trapezius and sternocleidomastoid. These muscles were chosen because of their relation to elementary movements such as shoulder elevation for trapeziuses and head rotation for sternocleidomastoids. The Teager-Keiser energy (TKE) operator is used in order to determine if a muscular onset is performed, and each motion of the person can be linked to an action of the arm. A calibration was done for each muscle in order to set a personalised detection threshold for onset detection. Finally, a real time predictive filter has been added in order to increase the sensitivity of the system. The result of the project was the complete achievement of a prototype controling a robotic arm using EMG signals of the user. The validity of the system was then tested in a study including 10 healthy individuals. This project represent a step towards technical assistance brought to spinal cord injury persons and the improvement of their living conditions.

Date	1 Oct 2013
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Rachid Aissaoui (Supervisor)