Development of a low-cost high-impact resistant compliant myoelectric prosthetic hand

Repeated mechanical failure due to accidental impact and lack of sensory feedback are one of the main reasons why people with upper-limb amputations abandon commercially-available prosthetic hands. To address this problem, this thesis presents the design and evaluation of a compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant and the integration of electromyographic (EMG) motor control and sensory substitution. The mechanism of our design replaces both the rigid input and coupler links with a monolithic compliant bone, and replaces the follower link with three layers of pre-stressed spring steel. This design behaves like a conventional four-bar linkage but adds lateral compliance and eliminates a pin joint, which is a main site of failure on impact. We introduce the fabrication process of the compliant finger and palm that enables the 3-D printed low-cost prosthetic hand to be impact resistant. This fabrication process and hand design enables the development of the prosthetic hand to be low-cost, light-weight, and easy to assemble and reproducible. Results from free-end and fixed-end impact tests show that, compared to those made with a conventional four-bar linkage, fingers made with our design absorb up to 11 % more energy on impact with no mechanical failure. Also our hand showed that it has grasping performance comparable to commercially-available hands. We also evaluate the sensorimotor capabilites of our hand with a subject with a transradial amputation. We show that using contact reflexes and sensory substitution, when compared to standard myoelectric prostheses that lack these features, improves grasping of delicate objects like an eggshell and a cup of water both with and without visual feedback. Our hand is easily integrated into standard sockets, facilitating long-term testing of sensorimotor capabilities.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Choi, Kyung Yun

Contributors dc:contributor

• Bretl, Timothy Wolfe

• Robotic hand
• Myoelectric hand
• Prosthetic hand
• Compliant mechanism
• Soft robotics
• Manufacturing
• Fabrication
• 3D printing
• Additive manufacturing
• Low-cost
• Open source
• Sensory feedback
• Design

Statement dc:rights

• Copyright 2017 Kyung Yun Choi

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/97463

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/97463