Colloquia

Summary

This thesis details the second stage of the Op Ooghoogte project. The “Op Ooghoogte” project aims to create a standing wheelchair add-on for paraplegic individuals with spinal cord injuries (T10-L3) to improve social engagement. Existing products are challenging to transport, heavy, and expensive, and they need improvements in physical ergonomics. The original design in the “Op Ooghoogte” project, the STODLA-1, incorporated a gas spring lifting mechanism. The problem with this concept was that it could not be manufactured due to the required gas spring not being available in retail, and it would be problematic to get in a neutral sitting position when accidentally engaged.

The research in this thesis introduces STODLA-2, an enhanced design featuring a pulley-based system to improve functionality, stability, and user autonomy. The study was conducted on the target group's upper body strength and core stability, addressing a notable gap in connecting core strength with upper extremity force production to guide the redesign process. User tests were developed and approved to evaluate the impaired user’s pulling strength, the seated manoeuvring of weight, and the identification of points of contact for the user’s feeling of safety. Due to time constraints, practical tests could not be conducted. Instead, relevant biomechanical studies on upper extremity force production in paraplegic individuals were used to approximate user capabilities.

Drawing from the insights of the literature, a revised set of requirements was established to steer the development of STODLA-2. The updated system consists of a four-pulley lifting mechanism, a unidirectional locking feature, a harness, and a cart structure designed for load-bearing and prototyping. A functional prototype was constructed, and its essential lifting and locking functions were successfully demonstrated.

Although STODLA-2 is not currently market-ready, its renewed lifting system and added stability have the potential for a lighter, more ergonomic, more transportable, and cost-effective alternative to current standing assistance devices. STODLA-2 may fill a gap in assistive technology for wheelchair users participating in social activities if further improved.