Development and Validation of a Caster Data Logger for Quantitative Measurement of Electric Powered Wheelchair Usage

Electric powered wheelchairs (EPWs) are an important form of mobility for many persons with disabilities. However, little quantitative data exists on how much people use their EPWs in real-world environments. Previous devices have been successful at measuring EPW usage, but they have been limited by the size or the battery life of the device. This study describes the design, development, and validation of caster data logger (CDL) suitable for long-term collection of EPW usage data in real-world environments. Also included in this study is a description of EPW usage data collected during and after the National Veterans' Wheelchair Games (NVWG). Several device concepts for logging EPW usage were evaluated. A caster data logger concept was chosen and functional prototypes were fabricated. The prototypes were subjected to a variety of bench tests before being deemed suitable for field use. 10 CDLs were constructed of data collection at the NVWG. At the NVWG, subjects who used an EPW as their primary means of mobility were recruited for this study. In 5 days at the games the participants (n=5) traveled a distance of 7751 ± 3439m per day, while traveling 3397±1300 m (n = 4) per day during 5 days the following week. The results were limited due to small sample size; however, they could provide useful pilot data for future studies.Overall, the CDL showed potential as a useful tool for measuring EPW usage. Future development should focus making the device easier for researchers and clinicians to use

Design and Development of Assistive Robots for Close Interaction with People with Disabilities

People with mobility and manipulation impairments wish to live and perform tasks as independently as possible; however, for many tasks, compensatory technology does not exist, to do so. Assistive robots have the potential to address this need. This work describes various aspects of the development of three novel assistive robots: the Personal Mobility and Manipulation Appliance (PerMMA), the Robotic Assisted Transfer Device (RATD), and the Mobility Enhancement Robotic Wheelchair (MEBot). PerMMA integrates mobility with advanced bi-manual manipulation to assist people with both upper and lower extremity impairments. The RATD is a wheelchair mounted robotic arm that can lift higher payloads and its primary aim is to assist caregivers of people who cannot independently transfer from their electric powered wheelchair to other surfaces such as a shower bench or toilet. MEBot is a wheeled robot that has highly reconfigurable kinematics, which allow it to negotiate challenging terrain, such as steep ramps, gravel, or stairs. A risk analysis was performed on all three robots which included a Fault Tree Analysis (FTA) and a Failure Mode Effect Analysis (FMEA) to identify potential risks and inform strategies to mitigate them. Identified risks or PerMMA include dropping sharp or hot objects. Critical risks identified for RATD included tip over, crush hazard, and getting stranded mid-transfer, and risks for MEBot include getting stranded on obstacles and tip over. Lastly, several critical factors, such as early involvement of people with disabilities, to guide future assistive robot design are presented