Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint

Hand rehabilitation robots were developed to assist in rehabilitation procedures conducted by rehabilitation professionals. However, current hand rehabilitation robots are mostly made from heavy and rigid structures that caused discomfort and fitting issues to the patients. McKibben actuator is a ty...

Full description

Saved in:

Bibliographic Details
Main Author:	Sii, Zhi Ying
Format:	Thesis
Language:	English
Published:	2021
Subjects:	TK Electrical engineering Electronics Nuclear engineering
Online Access:	http://eprints.utm.my/id/eprint/101702/1/SiiZhiYingMSKE2021.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.101702
record_format	uketd_dc
spelling	my-utm-ep.1017022023-07-03T07:54:02Z Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint 2021 Sii, Zhi Ying TK Electrical engineering. Electronics Nuclear engineering Hand rehabilitation robots were developed to assist in rehabilitation procedures conducted by rehabilitation professionals. However, current hand rehabilitation robots are mostly made from heavy and rigid structures that caused discomfort and fitting issues to the patients. McKibben actuator is a type of soft actuator that could be used in hand rehabilitation robots for its flexibility and light weight. However, it has a limited contraction ratio for the required range of motion for finger flexion. In this thesis, a pulley mechanism is proposed to improve McKibben actuator’s contraction ratio while providing the required contraction force. A double groove pulley made of a hybrid of gear and pulley is proposed to enhance McKibben’s actuator contraction ratio. Various pulley ratio was studied to find optimum contraction ratio and its relation to contraction force. A pulley ratio of 1:4 increases the contraction ratio from 19.85 % to 76.67 % but reduces the contraction force from 42.68 N to 9.69 N. Hence, pulley ratio of 1:2 was implemented to the McKibben linear actuator based on its optimized 39.72 % contraction ratio and 20 N contraction force for the soft splint application. Next, an adjustable finger size soft splint with fixed wrist motion was developed. It consists of three parts, namely pulley-based McKibben actuator, wrist component, and McKibben ring actuators. The wrist component was designed with an adjustable strap buckle while the finger insertion part utilized the elasticity of McKibben ring actuator during contraction to fit a wide range of sizes. The size range for wrist and hand circumference is 12 cm - 21.6 cm and 15.8 cm - 22.3 cm respectively, which fit 90 % of Malaysian young adults. The soft splint was tested on two healthy subjects. At 400 kPa supply pressure, the bending angle of the finger joints achieved was [71.8°, 72.8°, 18.70] for Metacarpophalangeal, Proximal Interphalangeal and Distal Interphalangeal respectively. The range of motion achieved by the soft splint is lower than the functional range of motion, but higher compared to other research works. The subjects were able to grasp and lift objects of different shapes including a box, cylinder, and irregular shape under 250 g while wearing the soft splint. The developed soft splint with adjustable McKibben ring actuators and pulley-based McKibben linear actuator could initiate finger motion and assist object grasping for a possible clinical hand rehabilitation assessment. 2021 Thesis http://eprints.utm.my/id/eprint/101702/ http://eprints.utm.my/id/eprint/101702/1/SiiZhiYingMSKE2021.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:149101 masters Universiti Teknologi Malaysia, Faculty of Engineering - School of Electrical Engineering Faculty of Engineering - School of Electrical Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TK Electrical engineering Electronics Nuclear engineering
spellingShingle	TK Electrical engineering Electronics Nuclear engineering Sii, Zhi Ying Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint
description	Hand rehabilitation robots were developed to assist in rehabilitation procedures conducted by rehabilitation professionals. However, current hand rehabilitation robots are mostly made from heavy and rigid structures that caused discomfort and fitting issues to the patients. McKibben actuator is a type of soft actuator that could be used in hand rehabilitation robots for its flexibility and light weight. However, it has a limited contraction ratio for the required range of motion for finger flexion. In this thesis, a pulley mechanism is proposed to improve McKibben actuator’s contraction ratio while providing the required contraction force. A double groove pulley made of a hybrid of gear and pulley is proposed to enhance McKibben’s actuator contraction ratio. Various pulley ratio was studied to find optimum contraction ratio and its relation to contraction force. A pulley ratio of 1:4 increases the contraction ratio from 19.85 % to 76.67 % but reduces the contraction force from 42.68 N to 9.69 N. Hence, pulley ratio of 1:2 was implemented to the McKibben linear actuator based on its optimized 39.72 % contraction ratio and 20 N contraction force for the soft splint application. Next, an adjustable finger size soft splint with fixed wrist motion was developed. It consists of three parts, namely pulley-based McKibben actuator, wrist component, and McKibben ring actuators. The wrist component was designed with an adjustable strap buckle while the finger insertion part utilized the elasticity of McKibben ring actuator during contraction to fit a wide range of sizes. The size range for wrist and hand circumference is 12 cm - 21.6 cm and 15.8 cm - 22.3 cm respectively, which fit 90 % of Malaysian young adults. The soft splint was tested on two healthy subjects. At 400 kPa supply pressure, the bending angle of the finger joints achieved was [71.8°, 72.8°, 18.70] for Metacarpophalangeal, Proximal Interphalangeal and Distal Interphalangeal respectively. The range of motion achieved by the soft splint is lower than the functional range of motion, but higher compared to other research works. The subjects were able to grasp and lift objects of different shapes including a box, cylinder, and irregular shape under 250 g while wearing the soft splint. The developed soft splint with adjustable McKibben ring actuators and pulley-based McKibben linear actuator could initiate finger motion and assist object grasping for a possible clinical hand rehabilitation assessment.
format	Thesis
qualification_level	Master's degree
author	Sii, Zhi Ying
author_facet	Sii, Zhi Ying
author_sort	Sii, Zhi Ying
title	Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint
title_short	Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint
title_full	Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint
title_fullStr	Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint
title_full_unstemmed	Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint
title_sort	pulley-based mckibben actuator mechanism for adjustable soft hand rehabilitation splint
granting_institution	Universiti Teknologi Malaysia, Faculty of Engineering - School of Electrical Engineering
granting_department	Faculty of Engineering - School of Electrical Engineering
publishDate	2021
url	http://eprints.utm.my/id/eprint/101702/1/SiiZhiYingMSKE2021.pdf
_version_	1776100751559360512

Pulley-based McKibben actuator mechanism for adjustable soft hand rehabilitation splint

Similar Items