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Developing product quality standards for wheelchairs used in less-resourced environments

MHATRE, Anand
MARTIN, Daniel
MCCAMBRIDGE, Matt
REESE, Norman
SULLIVAN, Mark
SCHOENDORFER, Don
WUNDERLICH, Eric
RUSHMAN, Chris
MAHILO, Dave
PEARLMAN, Jon
2017

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Background: Premature failures of wheelchairs in less-resourced environments (LREs) may be because of shortcomings in product regulation and quality standards. The standards published by the International Organization for Standardization (ISO) specify wheelchair tests for durability, safety and performance, but their applicability to products used in the rugged conditions of LREs is unclear. Because of this, wheelchair-related guidelines published by the World Health Organization recommended developing more rigorous durability tests for wheelchairs.


Objectives: This study was performed to identify the additional tests needed for LREs.


Methods: First, a literature review of the development of ISO test standards, wheelchair standards testing studies and wheelchair evaluations in LREs was performed. Second, expert advice from members of the Standards Working Group of the International Society of Wheelchair Professionals (ISWP) was compiled and reviewed.


Results: A total of 35 articles were included in the literature review. Participation from LREs was not observed in the ISO standards development. As per wheelchair testing study evidence, wheelchair models delivered in LREs did not meet the minimum standards requirement. Multiple part failures and repairs were observed with reviewed field evaluation studies. ISWP experts noted that several testing factors responsible for premature failures with wheelchair parts are not included in the standards and accordingly provided advice for additional test development.


Conclusion: The study findings indicate the need to develop a wide range of tests, with specific tests for measuring corrosion resistance of the entire wheelchair, rolling resistance of castors and rear wheels, and durability of whole wheelchair and castor assemblies.

Development of wheelchair caster testing equipment and preliminary testing of caster models

MHATRE, Anand
OTT, Joseph
PEARLMAN, Jonathan
2017

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Background: Because of the adverse environmental conditions present in less-resourced environments (LREs), the World Health Organization (WHO) has recommended that specialised wheelchair test methods may need to be developed to support product quality standards in these environments. A group of experts identified caster test methods as a high priority because of their common failure in LREs, and the insufficiency of existing test methods described in the International Organization for Standardization (ISO) Wheelchair Testing Standards (ISO 7176).


Objectives: To develop and demonstrate the feasibility of a caster system test method.


Method: Background literature and expert opinions were collected to identify existing caster test methods, caster failures common in LREs and environmental conditions present in LREs. Several conceptual designs for the caster testing method were developed, and through an iterative process using expert feedback, a final concept and a design were developed and a prototype was fabricated. Feasibility tests were conducted by testing a series of caster systems from wheelchairs used in LREs, and failure modes were recorded and compared to anecdotal reports about field failures.


Results: The new caster testing system was developed and it provides the flexibility to expose caster systems to typical conditions in LREs. Caster failures such as stem bolt fractures, fork fractures, bearing failures and tire cracking occurred during testing trials and are consistent with field failures.


Conclusion: The new caster test system has the capability to incorporate necessary test factors that degrade caster quality in LREs. Future work includes developing and validating a testing protocol that results in failure modes common during wheelchair use in LRE.

Quantitative Exploratory Evaluation of the Frequency, Causes and Consequences of Rehabilitation Wheelchair Breakdowns delivered at a Paediatric Clinic in Mexico

TORO, M L
GARCIA, Y
OJEDA, A M
DAUSEY, D J
PEARLMAN, J
2012

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Purpose: The United Nations Convention on the Rights of Persons with Disabilities recognises assistive technology such as wheelchairs (WCs) as a tool for social inclusion for this population. In less resourced settings, organisations lack information about effective models of WC service provision. The goal of this study was to investigate the lifespan of WCs and whether they provided reliable mobility, at one clinic in Mexico.

 

Methods: Caregivers of children, who had requested replacements for their WCs from a clinic in Mexico, were interviewed in Spanish. Among others, the questions pertained to repairs/modifications, adverse events and WC usage characteristics. The owners exchanged their WCs for new ones at the clinic, and the maintenance status of each returned WC was evaluated using the WC Assessment Checklist (WAC).

 

Results: Twenty-three donated WCs, used by children aged 3 to 14 years for an average of 19 months, were evaluated. Brakes (n=18), seat and back-sling upholstery (n=11 and 7 respectively), and armrests (n=14) were the components that failed most frequently. A total of 26 adverse events due to WC failure were reported. Adverse events were significantly associated with poor WAC scores (rs=-0.544, p=0.007).

 

Conclusions: Poor WC reliability, associated with adverse events which could undermine social engagement, indicates the need for a stronger WC and for regular maintenance. For instance, brake failures which were most often associated with adjustment issues, could have been resolved with maintenance, while seat and back-sling upholstery and armrest failures suggest that the WC may not be appropriate for the environment. Future work should investigate the robustness of these WCs using standardised methods (ISO 7176), as well as the impact of maintenance interventions on WC reliability.

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