Mechanical design of a biologically inspired prosthetic hand, the touch hand 3.

Abstract

The Touch hand 3 was developed to improve on the mechanical and mechatronic design of the Touch hand 2. A basic prototype hand was rapidly developed using 3D CAD software and 3D printing and tested on an amputee. The improvements in the final design included an improved finger actuation system utilizing mechanical linkages, an improved Electromyography (EMG) operated control system, four micro-linear servo-motors, modular fingers, hinges and chassis. The final design was designed such that the hand can be easily interchanged between a fully mechatronic system and full mechanically operated system using the same generic parts including the chassis, finger and wrist components. The hands were both tested with the Yale Open Hand test, a test used to assess robotic grippers. The Southampton Hand Assessment Procedure (SHAP), a test usually used to assess the effectiveness of upper limb prostheses, was also carried out on both versions of the hand. The hands were also tested with a hand dynamometer to assess their grip strength. The hand were compared to current hands on the market and their strength and weaknesses analysed.