Organizational Unit:

Rehabilitation Engineering and Applied Research Lab (REAR Lab)

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https://hdl.handle.net/1853/71920

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Organizational Unit

School of Industrial Design

Organizational Unit

George W. Woodruff School of Mechanical Engineering

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Now showing 1 - 10 of 32

Wheelchair in-seat monitoring design considerations

(Georgia Institute of Technology, 2022-10) Sprigle, Stephen ; Sonenblum, Sharon Eve ; Deshpande, Yogesh ; Jordan, Kathleen

Wheelchair in-seat activity trackers are developed to monitor and provide feedback about the pressure redistributing movements of wheelchair users, including weight shifts and other postural shifts that redistribute buttocks pressures. From a design perspective, in-seat activity trackers reflect myriad design decisions that impact performance, function, and usability. Many, if not all, of these decisions involve interconnections across system components, and can have significant impact on tracker operation and user-experience. Technology developers will have to manage many benefits and trade-offs that accompany design of each subsystem. Two documents were created based upon real-world use of in-seat trackers to briefly identify design criteria and constraints that should be considered.
Procedure to categorize wheelchair cushion performance using compliant buttock models

(Georgia Institute of Technology, 2022-09) Sprigle, Stephen ; Deshpande, Yogesh

Purpose: Wheelchair cushion prescription often seeks to address tissue integrity in addition to other clinical indicators. Because hundreds of wheelchair cushion models are available, a benefit would result if cushions were classified in a more valid manner to help guide selection by clinicians and users. The objective of this research was to develop an approach to evaluate and classify wheelchair cushion performance with respect to pressure redistribution. Materials and methods: Two anatomically-based buttock models were designed consisting of an elastomeric shell that models overall buttock form and a rigid substructure that abstracts load-bearing aspects of the skeleton. Model shapes were based upon elliptical and trigonometric equations, respectively. Two performance parameters were defined, pressure magnitude and pressure redistribution. The pressure magnitude parameter compared internal pressure values of the test cushion to a flat foam reference material, resulting in three classifications, superior, comparable, and inferior. Surface sensors were used to distinguish cushions with high, moderate or low pressure redistribution performance. Ten wheelchair cushions were evaluated by both models using two loads that represent a range of body weights expected for 41–43 cm wide cushions. Results and Conclusion: A classification matrix is proposed using both models and performance parameters. Two cushions met criteria for the highest level of performance, and one cushion was deemed to have inadequate performance for therapeutic value. The proposed method has a sensitivity to discern differences, compatibility with different sized cushions, and a versatility in classification. As such, it stands as an improvement over existing classification approaches.
The Design of a Family of Parametric Anatomically-Based Compliant Buttock Models to Evaluate Wheelchair Cushion Performance - Fabrication Package

(Georgia Institute of Technology, 2022-07) Deshpande, Yogesh ; Sprigle, Stephen

The evaluation of wheelchair cushion performance is of interest to a variety of stakeholders. Over the years, several buttocks models have been used to evaluate wheelchair cushion performance. These vary in design and purpose, and can be generally classified as either rigid or compliant. To date, published studies using buttock models have been limited to using a single size model. Thus, they were designed to evaluate one size of cushions. A need exists to define a series of models that can be used to evaluate cushions of varying sizes. The objective of this project was to develop a family of compliant buttock models that are based upon the anatomical parameters of persons with varying body sizes. This paper will detail the designs, describe the anatomical basis for the design and provide the rationale for the design decisions. Supplemental material includes greater detail; the full CAD files and model fabrication instructions are available in an open access repository for persons who wish to fabricate the models.
Mechanical performance characterization of manual wheelchairs using robotic wheelchair operator with intermittent torque-based propulsion

(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.
Designing an Ergonomic Infant-to-Toddler Rocker Based on Anthropometric Data

(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.
Using Anthropometric Measurements to Design Ergonomic Infant and Toddler Gear

(Georgia Institute of Technology, 2019-12-05) Pardue, Emily Louisa

Infants grow so quickly that gear can have a shockingly short life span. Parents often do a quick calculation before purchases: divide the cost by how many months it will be used. Thus, products that are meant to “grow-with-me” or last for multiple infant stages are extremely desirable. Infant-to-toddler rockers are an example of this type of product. However, the researchers have found that the current infant-to-toddler rocker models on the market could be improved. The goal of this project was to use anthropometric data of children to design an ergonomic infant-to-toddler rocker. Anthropometric data was collected on 58 children in order to properly size a new design for a rocker which lasts from 0 to 36 months old. Researchers also found based on parent interviews, a survey, and child interactions, that the needs of infants are very different from the needs of toddlers. Infants are still developing muscle tone, and it is important for them to be supported in a semi-reclined position. Toddlers are extremely active and need a device which allows them to ingress and egress independently. Concepts were developed, and prototypes built to demonstrate the new concepts. These prototypes were then tested with parents and children to gather feedback and improve designs. The final design is an ergonomic rocker which adjusts in size and recline angle to serve the infants that need to be secure and reclined, as well as the ambulatory toddlers.
System design of an activity tracker to encourage behavioral change among those at risk of pressure ulcers

(Georgia Institute of Technology, 2019-04-24) Obrien, John James

The Wheelchair In-Seat Activity Tracker (WiSAT) is a sensor-based activity tracker aimed at encouraging in-seat movement among wheelchair users who are at risk of pressure ulcers. Pressure ulcers tend to form in the buttocks or thighs of a wheelchair user due to a lack of pressure redistribution in that part of the body. Pressure ulcers are a serious risk to many wheelchair users due to a plethora of harmful side-effects, such as infection, hospitalization, and long recovery times. However, in-seat movements, such as weight shifts, have been linked with the occurrence of pressure ulcers. WiSAT began as a research tool that enabled researchers to monitor the in-seat activity of wheelchair users during their daily lives through sensor-based reporting, as opposed to relying solely on the self-reporting of research participants. Through the efforts described in this thesis, WiSAT was transformed from a research tool into a consumer product. Specifically, this thesis describes the design, development, and integration of WiSAT’s subsystem through four specific aims: 1. Design and evaluation of a user-interface based upon principles of Health Behavioral Change Theory. 2. Coupling of the Hardware and Smartphone App Subsystems 3. Preparation of the Algorithm Subsystem 4. Integration of the WiSAT Subsystems through Multi-layered Architecture for the WiSAT Smartphone App
Encourage sedentary workers' active seating through product design

(Georgia Institute of Technology, 2018-07-31) Ni, Chenan

The purpose of this project is to design a perturbation system for encouraging active sitting. This product would improve the physical environment within which the sedentary workers work and reduce their incidence of musculoskeletal discomfort. Specifically, the sedentary workers would be able to slightly shift postures without being disturbed by the device through an intervention, therefore, encouraging in-seat movement.
User specific assistive technology: Hand mounted switch control platform design

(Georgia Institute of Technology, 2018-04-27) Yuan, Xiuxiu

The purpose of this project is to design a platform for user specific assistive technology. This platform would allow occupational therapists to design and deliver highly customizable hand mounted switch controls for persons with severe disabilities using rapid prototyping tools. Specifically, occupational therapists would be able to adjust a pre-designed model through an intuitive user interface therefore change the design to meet users’ unique needs. The study first conducted literature review about assistive technology and rapid prototyping, then used participatory approach and human centered design methodology, engaged three occupational therapists to design and develop the platform through workshops and interviews. The aims of this project including designing the switch device, platform user interface and system packaging, and evaluating the designs with the occupational therapists. Findings, limitations and future work were discussed in the end.
Assistive Technology Outcomes Measure (ATOM) v2.0

(Georgia Institute of Technology, 2018) Sprigle, Stephen ; Harris, Frances