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

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

Choi, Kyung Yun ; Bretl ; Timothy Wolfe

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

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/97463/CHOI-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

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.