System to Apply Continuous Forces to People Walking; Assistive Devices Should Make Lives Easier, Not Better: Highlighting Voices from Disabled People on Assistive Devices

My technical and STS research topics investigated the development and usage of assistive technologies for disabled people. Assistive technologies include walkers, wheelchairs, or insulin pumps, that help support activities of daily living for those with uneven gait patterns or other disabilities. My technical project focuses on developing a system to apply assistive forces to reduce the metabolic demand of walking for those with uneven gait patterns, such as those with cerebral palsy or the elderly. My STS research examines the dialogue within the disabled community regarding the usage of assistive devices and the relationship between disabled people and technologies as a reflection of society.

The primary goal of my technical work was to design and build a system to apply assistive forces to people walking overground and evaluate changes to their gait in healthy populations. Walking requires one to expend large amounts of energy, especially for certain clinical populations such as individuals with cerebral palsy. Previous studies have found applying assistive forces decreased the metabolic demand of walking, however, these studies were performed on treadmills that do not accurately represent overground walking. For my technical work, I designed a system with my team to apply assistive forces to people walking across the 10 m lab space in the Motion Analysis and Motor Performance Lab (MAMP) at UVA. The system we designed was composed of a motor and spool attached to a wall, a load cell to measure output force, and a pulley to ensure frictionless transfer of linear forward force to the person walking. A frictionless exercise belt was attached to the person’s pelvis and a rope pulled the person forwards towards the wall as the motor applied a constant pulling force of about 5% or 10% of the person’s body weight (BW). We designed a custom proportional integral (PI) controller in MATLAB to ensure the force was being applied constantly throughout the person’s gait cycle. There was a significant increase in step length with 10 % BW and an increasing trend of stride length, which is consistent with previous research in assistive forces. The motor was capable of applying a constant force profile with a 10 lb weight. However, there were increased variabilities when applied to a person walking. These limitations are most likely due to the slow motor response time within the current system. We initially wanted to measure energy expenditure, however, due to limitations with the motor we were using, we focused on gait changes such as spatio-temporal parameters and gait kinematics examined from motion capture data.

My STS research analyzes the intertwined relationship between assistive technologies and disabled people. I specifically focused on highlighting various voices within the disabled community that have differing opinions regarding the role of assistive technologies in their lives. Some of these influential voices include Ashley Shew, Katherine Ott, and Hugh Herr. My research also examined the role of assistive technology as an intrinsic system designed for individuals with disabilities that directly respond to society’s viewpoints on disability. Additionally, I wanted to share familiar experiences of disabled people from the UVA community by conducting a personal interview with a current UVA undergraduate student to recognize their experiences with disability on grounds. I argue that assistive technologies should not be designed to make the lives of disabled people better, but rather help disabled people live their lives easier. While this may be a subtle distinction, this clarifies the narrative surrounding disabilities and assistive technologies, such that disabled people are not disadvantaged if they choose to live without specific assistive technologies. Assistive technologies have provided many people with a way of integrating into society and gaining independence in their daily lives. However, they should not be glorified and viewed as a method of getting rid of disabilities entirely. Future research should focus on promoting knowledge and education of disabled communities such that their experiences are normalized rather than shamed.

Working on both of these projects at the same time throughout the year bolstered my understanding for the disabled community when discussing assistive technologies. Throughout my technical project, I became more cognizant of the impact I would have through the development of my design and was encouraged to take a more realistic approach when choosing research goals and outcome measures we wanted to achieve. I realized that performing research to improve assistive technology had a direct impact on disabled people and can influence their interactions with society. While the goal of my technical project would be to help disabled people have greater independence through walking, I now understand that this goal is harder to attain not only through technological barriers, but also societal ones. As a researcher and engineer, I must be congnizant that my future innovations are intertwined with how they will directly impact the users and the society around them. My technical project does not live in a void with only one specific user, but rather can have greater implications on how disabled communities already interact with the world. While I hope that my design brings forth greater innovations that leads to the betterment of people’s lives, I now have a greater and deeper understanding of the daily struggles and journeys disabled people live with everyday, independent of their technologies. Disabled people’s lives are not greatly improved by technology, but rather my goal as a biomedical engineer would be to ensure I can help make their lives easier.

School of Engineering and Applied Science

Bachelor of Science in Biomedical Engineering

Technical Advisor: Shawn Russell

STS Advisor: Joshua Earle

Technical Team Members: Thomas Brown