[5A7] Design and development of an exoskeleton prototype arm utilising electromyography

J Gornall, B Mandia, L Downing and R Saatchi
Sheffield Hallam University, UK 

Individuals who lack or have significant difficulties utilising their arms and hands may benefit from having an exoskeletal arm to gain some independence in their daily lives. This paper outlines the design and implementation of a prototype electro-mechanical arm. The mechanisms utilise cable-drawn pulleys to provide controlled-angle three degrees of freedom (DOF) for index, middle and ring and the shoulder. The elbow has a single DOF. The aim was to build a prototype wearable prosthetic mechanism for the whole arm that could perform some basics daily tasks.

Furthermore, it was intended that the prosthetic mechanisms assist with some physiotherapy activities, which might be helpful for individuals with muscle degenerative diseases. The arm was controlled by either utilising electromyography (EMG) signals recorded by placing sensors on the arm or by utilising a joystick interface. The actuation of its DC motors was programmed to reflect the user's muscle activities and to allow the user to control the modules smoothly and accurately. A graphical 3D animation was implemented in MATLAB© Simulink© to demonstrate the arm’s operation, while the hardware was interfaced through LabVIEW©. The components were designed in Solidworks and 3D printed.

The prosthetic mechanism was able to lift objects up to 2 kg. The mechanism provided accurate position control for moving objects and physiotherapy. The basic daily activity of drinking was achieved; however, this required development.