Improved Kinematics for Upper Limbs Prostheses

Abstract

Gripping an object remains the main weakness of most modern prostheses even though they offer a greater degree of freedom than ever before. By examining the kinematics of gripping on healthy limbs and comparing them with the prostheses kinematics we can determine the restrictions of the prosthesis and propose solutions to eliminate them. The aim of the study was to find the differences in grasping an object between a healthy hand and with prosthesis. Creating a virtual model of the prosthesis and healthy hand allowed for the identification of limitations in the function of the prosthesis. Using the videographic method the difference in kinematics during the grasping motion of two different objects was investigated. Based on different trajectories, two model variants are constructed in the ADAMS/View software. A control strategy system in the program ADAMS is proposed to correct the kinematic limitations of the prosthesis and mimic the kinematics of a healthy hand. By improving the prosthesis kinematics, its function can more closely imitate a healthy human limb.