Pneumatically Actuated Soft Wearable Exoskeleton for Upper Limb Motion Rehabilitation; Limitations to the Access of Wearable Robotics

For my technical project, myself and a group of five other mechanical engineering students designed a pneumatically actuated soft wearable exoskeleton for upper limb motion and rehabilitation. The target audience for this device is patients who lack shoulder mobility following a stroke. In this project, we aimed to achieve maximum range of motion for two motions of the shoulder: flexion/extension and abduction/adduction. In order to achieve our goals, there were three main objectives. The first objective was mechanical design. This was achieved primarily using Computer Aided Design to create a shoulder brace that permitted effective actuation methods. The final design included a large lever on the shoulder to run the actuators through, a shoulder brace, and a second connector piece on the opposite shoulder. The second objective was actuation. To achieve actuation, we utilized McKibben (artificial) muscles. These are bladder-like tubular structures that contract when air is pumped into them. We used two muscles to emulate the trapezius and bicep muscles which are primarily used to lift the arm up. The first muscle was connected from the elbow area and ran through the shoulder lever on the right arm. The second muscle was connected to the left shoulder and ran through the same shoulder lever. Each muscle was connected to a 12 volt pump that would fill the muscles with air allowing for contraction. Finally, the third objective was control. The pump was connected to an Arduino and double relay system and was controlled by a joystick. When the joystick was pressed in one direction, the relays would switch, allowing the pump to release air and fill up the muscles. When pressed in the opposite direction, the relays would switch to the opposite direction causing air to release through a solenoid with an airflow valve controlling the rate of release. After all three objectives were achieved, we created a working shoulder rehabilitation exoskeleton that allowed for approximately 90 degrees of motion in the abduction/adduction direction and 45 degrees of motion in the flexion/extension direction.

For my STS research paper, I explored the limitations in access to wearable robotics, particularly in the United States. Additionally, I looked at a variety of factors that cause the inevitable limited access that many users face when looking into rehabilitation options. Wearable robotics, a field that encompasses devices like exoskeletons, robotics prosthetics, and assistive devices, has the potential to revolutionize healthcare, rehabilitation, and mobility for individuals with disabilities. This technology can improve quality of life by enhancing physical capabilities and independence. However, despite the significant promise of wearable robotics, access to these devices remains restricted for many individuals. High price, geographical disparities, and restrictive insurance policies present substantial barriers to widespread adoption amongst those in need. The accessibility of rehabilitation robotics is deeply shaped by the social construction of these technologies. The interests of manufacturers, healthcare providers, insurance companies, policymakers, and users all influence the development, distribution, and adoption of these devices. While the potential for rehabilitation robotics to transform the lives of people with disabilities or chronic conditions is immense, the high cost, geographical constraints, and limitations of insurance policies continue to prevent widespread access and adoption. These barriers are not merely technical challenges but are shaped by the competing priorities and interests of different social groups. For rehabilitation technologies to become truly accessible, there must be a shift in how these technologies are viewed and prioritized by all relevant stakeholders, with a focus on making them affordable and accessible to those who need them most.

The connection between my STS research paper and technical project is clear and evident. Both papers explore how to find a mainstream solution to the issue of rehabilitation robotics. As explored in my STS research paper, the average annual cost for patients with similar disabilities to a stroke can be north of $100,000. Additionally, geographical constraints cause a variety of issues for individuals seeking care particularly in rural regions. Finally, insurance companies often view medical robotics as “too experimental” in nature and often do not give approval to entrepreneurs to bring their product to market. In my technical project, one of the main goals was to create a cheap and widely accessible option for stroke patients in need of shoulder rehabilitation. We had a budget of $1200 to achieve this goal and, although our final design is not market ready, we found ourselves way below that budget. The final product is usable by, at worst, the patient in need and one helper. Additionally, the product can be used at home in comparison to most current rehabilitation robotics that require a trip to the local hospital or clinic. Our product struggles to address the insurance company issue that is highlighted in my STS paper, but certainly addresses the other two issues in a significant way. My technical project potentially can serve as a baseline for future engineers to create a more comprehensive full arm rehabilitation device that can serve for full shoulder range of motion as well as elbow and wrist motion. I hope to see future students, engineers, and entrepreneurs continue to solve this issue of at-home, low cost rehabilitation robotics.

School of Engineering and Applied Science
Bachelor of Science in Aerospace Engineering
Technical Advisor: Sarah Sun
STS Advisor: Joshua Earle
Technical Team Members: Kaitlin Cole, Jahnavi Dave, Joshua Lim, Jackson Spain, Courtney Wilks