(Georgia Institute of Technology, 2020-12-06)
Misch, Jacob P.
The current manual wheelchair design process lacks consistent and objective connection to performance-based metrics. The goal of this research was to empirically assess over-ground manual wheelchair performances and identify important design trade-offs through the use of a robotic apparatus with a novel cyclic propulsion control method. This research had four specific aims: 1) to design, implement, and validate torque-based propulsion to emulate the intermittent human propulsion cycle with an existing robotic wheelchair tester, 2) to investigate the influence of incremental mass additions to the wheelchair frame on over-ground propulsion characteristics, 3) to demonstrably improve the performance of a representative high-strength lightweight wheelchair by leveraging existing component-level test results, and 4) to characterize the mechanical performances of representative folding and rigid ultra-lightweight wheelchair frames. The outcomes of this research include an objective, repeatable, and validated test method to assess over-ground performances of manual wheelchairs in realistic contexts of use, as well as insight on the mechanics of the system that were previously under-studied or confounded by variabilities within human subject testing. Controlled propulsion tests are used to identify differences between wheelchair configurations. The outcome variable of propulsion cost represents the energetic requirements of propelling each chair a given distance and has direct relevance to manufacturers, clinicians, and wheelchair users alike. Ultimately, these outcomes will inform clinicians and manufacturers about how configuration choices influence propulsive efforts, which can be used in turn to improve their classification techniques and existing design processes. This knowledge will additionally empower wheelchair users to make informed choices during the wheelchair selection process based on objective mechanical performance metrics.
(Georgia Institute of Technology, 2020-04-27)
Ryan, Caitlin Olivia
Currently ergonomics is not a term frequently associated with infant and toddler products. Many of these products on the market like highchairs, rockers and bouncers aren’t designed using anthropometric data on infants and toddlers. The project focused on gather anthropometric data from children between 0-36 months of age as well as aggregating historic data and utilize the measurements to design an ergonomic rocker that would transition or “grow” with a child from infant to toddler. This takes into account not only the objective size of the infants and toddlers but also designing for the differing use cases for each the infant and the toddler user. The infant users are still developing much of their muscle tone and require a rocker to support their feet in long sitting in a semi-reclined position. While toddlers require a rocker that facilitates upright short sitting as well as independent ingress and egress to accommodate their high activity levels. These disparate needs are not currently being met by similar products on the market leading to a shorted life cycle of the product. Anthropometric data was collected on 55 children and used in tandem with knowledge gained from parent surveys, parent interviews and interacting with children to design a new rocker. The prototype was evaluated by both parents and children to make necessary improvements to the design. The final prototype utilized all the information gathered throughout the entire project resulting in an ergonomic adjustable infant -to-toddler rocker.