Control of Finger Stiffness in Hand Prostheses

Abstract

The objective of this research is to improve the performance of hand prostheses by controlling finger stiffness in comercially available prostheses, finger stiffness cannot be modulated yet, stiffness may be helpful to stabilize a grasp and enhance the performance of a prosthesis. For instance, stiffness partially determines finger response to a perturbation. For a given displacement, the orientation of the restoring force varies with stiffness. Moreover, stiffness is the inverse of compliance: for a given external force, a low finger stiffness would result in a large finger displacement while a high stiffness results in a small displacement. In order to establish guidelines for the design of a prosthesis with compliant fingers, a theoretical study of human finger stiffness has been initiated. We want to investigate the range of endpoint stiffness in human finger.