Future-proof toilet design: A user-centred mixed-methods investigation

The toilet is a product that supports one of the most basic human functions. Its independent use marks one of the first milestones in every human life and maintaining this independence is a profound imperative throughout the ageing process. The primary aims of this thesis are to determine the effect of toilet seat height on the success of a toilet design for older Australians and to determine the effect of additional supportive surfaces on the success of a toilet design. The research was conducted with thirty-one Australians aged 62 to 89 years and involved user-centred mixed methods comprising semi-structured interview, anthropometric measurement, user-controlled fitting trial, design evaluation and motion trials. The findings of the semi-structured interview, presented in Chapter 4, demonstrate the extent to which toilet height is an issue to participants and other factors affecting the usability of the toilet. The evaluations of an unfamiliar armrest design are analysed using appraisal theories of response, indicating complex relationships between design and identity. The integrated findings of participants’ toilet height choices, including upper and lower acceptable limits, show that the mean preferred seated pan height was 398 mm (SD=8, n=31), close to standard height. Mean preferred transfer pan height was 421mm (SD=40, n=31), correlations to popliteal heights are explored. Participant reasoning for their choices and seat pressure mat recordings for all conditions are presented. Summarised biomechanical analysis of transfer motion trials is also reported. Integration of findings led to the development of design proposals with one developed in a subsequent study. This employed both laboratory focussed and codesign approaches to refine design details for a range of supportive bathroom accessories that were aligned with user needs and motivations. These designs have been accepted for commercialisation by the industry partner. For this group of older Australians, the success of a toilet design is affected by the task for which it is being evaluated, whether seated use or transfer. The preferred seated height finding aligns with current standard toilet height. The higher preferred transfer height aligns with research that higher seats reduce the effort to rise.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2018

Author dc:creator

• Sweatman, Peter

• Toilet design

Statement dc:rights

• open access
• CC BY-NC-ND 3.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by-nc-nd/3.0/au/

Language dc:language

EN

Identifier

https://doi.org/10.26190/unsworks/3792

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/63348