Design of an anthropomorphic underactuated hand prosthesis with passive-adaptive grasping capabilities

Abstract

This paper presents the design and mechanical features of a functional self-adaptive, multi fingered prosthetic hand that improves upon current prosthetic hands. Commercially available hand prostheses, though functional, have limitations such as weight, as result of vast numbers of parts, intricate mechanisms requiring constant maintenance as well as the extremely high cost to the user. The hands design discussed is based on an underactuated 15 degree-of-freedom, 1-degree-of-actuation configuration, fully capable of performing activities of daily living. Each finger is fully independent from each other and is designed to adapt to objects of any geometry while possessing the ability of pick up smaller objects through pinching, by means of a position adjustable thumb. The system provides safe and reliable grasping without the need for feed back sensors, multiple servos, or any type of data processing. The design is focused towards providing upper limb amputees with the option of a prosthetic hand that is cosmetically appealing, functionally comparable with other prosthesis of its type, while decreases cost and weight issues by using an approach that eliminates the need for complex electrical systems, circuitry, and multiple servomotors while decreasing the number of parts and cost of manufacturing.