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Utilizing Community Data and Laboratory Testing to Raise the Quality of Wheelchair Casters

Fried, John J (2022) Utilizing Community Data and Laboratory Testing to Raise the Quality of Wheelchair Casters. Master's Thesis, University of Pittsburgh. (Unpublished)

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Wheelchairs are pivotal for the mobility of people with spinal cord injuries and similar diagnoses. According to the World Health Organization, 75 million people need a wheelchair for mobility, access to education, employment, and social engagement. Despite the importance of wheelchairs in the everyday lives of their users, the growing research evidence on field evaluation of wheelchairs and laboratory-based testing has shown that manual and power wheelchairs suffer frequent failures in both high-income and less-resourced settings. The majority of wheelchair failures are suffered by the casters which poses a risk for the wheelchair to tip and the user to fall out of the wheelchair and get injured. To raise wheelchair caster quality, the ISO 7176-32 testing standard was developed. The standard incorporates shocks and environmental factors that affect caster quality. The standard has been validated to reproduce community failures in the laboratory.

The purpose of this thesis is to build further on this validation work and improve caster design, quality, and reliability. Chapter 1 provides background information regarding the need for quality wheelchairs and the current prevalence of caster failure experienced by users. The wheelchair standards research that has preceded and informed the work in this thesis is also detailed. Chapter 2 demonstrates the utilization of ISO 7176-32 and additional large data sets from the community for test validation. Analysis of the data found that tilt-in-space wheelchairs experienced nearly double the rate of high-risk failures as their ultralight counterparts. The study correlates the time-to-failure of wheelchair casters between community and laboratory settings and informs testing dosage specifically for tilt-in-space wheelchair casters. Chapter 3 focuses on caster design improvements by leveraging the testing capabilities of ISO 7176-32. Caster bearings and plastic bushings were tested until failures according to ISO 7176-32 and bushings were found to be more durable and cost-effective than bearings. Chapter 4 summarizes important conclusions of these chapters and the thesis, as well as the future work required to continue this research. Overall, this thesis highlights how laboratory testing can replicate community outcomes to increase device quality and performance, and ultimately improve user safety and independence.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Fried, John Jjjf70@pitt.edujjf700000-0002-5601-4853
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Thesis AdvisorMhatre, Anand Aanand.mhatre@pitt.eduaam1080000-0001-6179-3727
Committee ChairMhatre, Anand Aanand.mhatre@pitt.eduaam1080000-0001-6179-3727
Committee MemberPearlman, Jonathan Ljpearlman@pitt.edujlp460000-0003-0830-9136
Committee MemberSchmeler, Mark Rschmeler@pitt.eduschmeler0000-0001-8173-5452
Committee MemberBrienza, David Mdbrienza@pitt.edudbrienza0000-0001-6335-2925
Date: 9 September 2022
Date Type: Publication
Defense Date: 27 May 2022
Approval Date: 9 September 2022
Submission Date: 22 July 2022
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 55
Institution: University of Pittsburgh
Schools and Programs: School of Health and Rehabilitation Sciences > Rehabilitation Science and Technology
Degree: MS - Master of Science
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: Manual Wheelchair, Tilt-in-space, Ultralightweight, Caster, Standards, Repair, Time-to-failure, Failure, Breakdown, Environment, Corrosion, Thermoplastic, Bushing, Bearing, Durability, Cost-effectiveness
Date Deposited: 09 Sep 2022 15:14
Last Modified: 09 Sep 2022 15:14


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