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Rehabilitation Engineering and Applied Research Lab (REAR Lab)

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Now showing 1 - 10 of 13
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    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.
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    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.
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    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
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    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.
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    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.
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    Aiding lower-limb amputees in traversing uneven terrain through product design
    (Georgia Institute of Technology, 2015-08-21) Husack, Mark
    The majority of lower-limb amputations are not caused by trauma or cancer, but rather by vascular diseases brought on by Type 2 Diabetes. Many of these patients must have a limb amputated because they have led a sedentary lifestyle and maintained a poor diet for much of their lives. Having a limb amputated can be a wake-up call to these patients, giving them the motivation to change their lifestyle and become more physically active. However, many of these lower-limb amputees are on Medicare or Medicaid and are only covered for their basic walking needs. Due to the high out-of-pocket costs of specialized prostheses needed to perform specific physical activities, it can be more difficult for them to achieve that lifestyle change. This study aims to design a device that will aid lower-limb amputees in traversing uneven terrain with the intent of facilitating outdoor activities.
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    A smartphone application that informs weight shifting behavior to promote tissue health
    (Georgia Institute of Technology, 2015-08-18) Cheng, Philip
    One of the most persistent problems affecting wheelchair users is pressure ulcers. These are ulcers that wheelchair users develop in areas of constant pressure or interruption of blood flow to a localized area. Approximately one- third of patients who suffer from spinal cord injuries develop pressure ulcers, and it is a very expensive consequence for these people. Pressure relief exercises can help, but a high percentage of wheelchair users do not perform them enough. Activity trackers today have the ability to sync with smartphone applications to monitor physical activity. The following study uses weight shifting behavior to help wheelchair users. By studying principles of usability engineering and user interface design, the researcher will design a smartphone application that pairs with a weight shift monitoring system to help promote tissue health. The application will illustrate information for the user to make them aware of their behavior and engage them in pressure relief exercises.
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    Height adjustable wheelchair seat design
    (Georgia Institute of Technology, 2011-07-08) Li, Yiran
    Full time wheelchair users are at a height disadvantage during many function activities, such as transferring or reaching. Retrieving objects from the ground or a higher shelf while seated in the wheelchair can be both difficult and unsafe. Lateral transfers between surfaces at different heights can be difficult and unsafe. Sit-to-stand transfers are made simpler with a higher seat. This research project seeks to assist reach and transfers by designing a system to raise and lower a wheelchair seat over a 4'' range. The project included several needs assessment: 1) by conducting interviews and surveys, identify design needs from different stakeholder groups; 2) analysis of stakeholder groups' feedback and synthesis into design criteria; and 3) creation of design concepts for the adjustable height wheelchair seat; 4) evaluation of the design by setting up heuristic evaluation criteria and perform user testing; 5) design revision design based on user's performance and feedback. The design process included fabricating and testing of various concepts, validating design through user testing, and addresses technology transfer of the device.
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    Design and analysis of an inertial properties measurement device for manual wheelchairs
    (Georgia Institute of Technology, 2010-07-07) Eicholtz, Matthew R.
    The dynamics of rigid body motion are dependent on the inertial properties of the body - that is, the mass and moment of inertia. For complex systems, it may be necessary to derive these results empirically. Such is the case for manual wheelchairs, which can be modeled as a rigid body frame connected to four wheels. While 3D modeling software is capable of estimating inertial parameters, modeling inaccuracies and ill-defined material properties may introduce significant errors in this estimation technique and necessitate experimental measurements. To that end, this thesis discusses the design of a device called the iMachine that empirically determines the mass, location of the center of mass, and moment of inertia about the vertical (yaw) axis passing through the center of mass of the wheelchair. The iMachine is a spring-loaded rotating platform that freely oscillates about an axis passing through its center due to an initial angular velocity. The mass and location of the center of mass can be determined using a static analysis of a triangular configuration of load cells. An optical encoder records the dynamic angular displacement of the platform, and the natural frequency of free vibration is calculated using several techniques. Finally, the moment of inertia is determined from the natural frequency of the system. In this thesis, test results are presented for the calibration of the load cells and spring rate. In addition, objects with known mass properties were tested and comparisons are made between the analytical and empirical inertia results. In general, the mass measurement of the test object had greater than 99% accuracy. The average relative error for the x and y-coordinates of the center of mass was 0.891% and 1.99%, respectively. For the moment of inertia, a relationship was established between relative error and the ratio of the test object inertia to the inertia of the system. The results suggest that 95% accuracy can be achieved if the test object accounts for at least 25% of the total inertia of the system. Finally, the moment of inertia of a manual wheelchair is determined using the device (I = 1.213 kg-m²), and conclusions are made regarding the reliability and validity of results. The results of this project will feed into energy calculations for the Anatomical Model Propulsion System (AMPS), a wheelchair-propelling robot used to measure the mechanical efficiency of manual wheelchairs.
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    Tweel (TM) technology tires for wheelchairs and instrumentation for measuring everyday wheeled mobility
    (Georgia Institute of Technology, 2007-04-04) Meruani, Azeem
    This thesis is focused on two aspects related to wheeled mobility: 1) Evaluating the impact of a new tire design on powered mobility, and 2) Instrumentation that permits better monitoring and assessment of wheeled mobility in everyday use. The Tweel technology tires developed by Michelin USA are comprised of an outer polyurethane ring supported by polyurethane fins instead of metal spokes, which allow the tire to deflect under pressure. As a wheelchair tire they offer a potential breakthrough as they have deflection properties similar to a pneumatic tire while maintaining the low maintenance of a solid foam-core tire. A study was conducted to compare the Tweel technology tires to standard solid foam-core tires for vibration transmission, traction and overall life span. The Tweel technology tires failed produce any significant difference in vibration transmitted to the user compared to solid foam-core tires. Additionally, the Tweel technology tires showed significant signs of deterioration after a month long field trial, thus indicating a short life span. However, Tweel technology tires provided better traction on both dry and wet concrete. Overall, Tweel technology tires have to be re-engineered to provide better damping properties, leading to lower vibrational levels transmitted to the user. The second section this thesis addressed the need to develop a methodology of measuring mobility in everyday usage. This section is part of a greater ongoing research project at CATEA (Center for Assistive Technology and Environmental Access) aimed at understanding everyday wheelchair usage. Methodology was developed to measure bouts of mobility that characterize wheelchair usage; which includes the number of starts, stops, turns and distance traveled through the day. Three different technologies which included, Accelerometer unit on the rim of the drive wheel, Gyro-Accelerometer unit on the frame of the chair and Reed switches, were tested. Testing included various criteria for accuracy, durability and compatibility for measuring bouts of everyday wheeled mobility. Although a single technology could not be used to measure all aspects of mobility, the Accelerometer unit on the rim met the design criteria for measuring starts stops and distance, while the Gyro-Accelerometer unit met the requirements for measuring turns.