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

Choi, Kyung Yun

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https://hdl.handle.net/2142/97463 Copy

Description

Title

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

Author(s)

Choi, Kyung Yun

Issue Date

2017-04-28

Director of Research (if dissertation) or Advisor (if thesis)

Bretl, Timothy Wolfe

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

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

Abstract

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.

Graduation Semester

2017-05

Type of Resource

text

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

Copyright and License Information

Copyright 2017 Kyung Yun Choi

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