Design of a low-cost, reconfigurable, standing wheelchair with easy and stable sit-stand-sit transition capability.

ABSTRACT

PURPOSE: Assistive devices like Standing Wheelchairs (SWC) have remained out of reach of the economically underprivileged even before the pandemic-induced financial downturn, and more so now. This paper describes the mechanical design of a manual user-actuated SWC that is cost-effective (equivalent of USD 210 in India, ex-factory) and has special features that minimise user effort and accommodates varying body weights (50-110 kg) and dimensions (1.52-1.83 m height). METHODS: The design includes a six-bar mechanism and spring balancing to optimise user effort during operation. The optimised gas spring incorporates adjustability to minimise each user's force for sit-stand-sit transitions. The handle shape is ergonomically designed using kinematic analysis to provide convenient gripping positions for actuation. The design has been customised based on parametric studies to suit varying body weights. RESULTS: Overall, the SWC design provides standing functionality with ease of operation, safety locks, customisability, affordability, outdoor mobility and is aesthetically pleasing. CONCLUSIONS: Customisability and the low cost of the device would enhance the accessibility of the SWC to a larger group of eligible users.Implications for rehabilitationManual user-operated standing wheelchair design using a six-bar mechanismSpring balancing used to reduce user effort to self-lift to the standing positionKinematic analysis used to determine convenient handle location for user easeCustomisability for wide range of users to ensure correct posture, optimal effortDesign refined through multiple iterations using inputs from users and cliniciansDesign commercialised at an affordable cost, making it accessible to a larger population.