Through UW’s BME Design Course, I’ve had the opportunity to design a prosthetic ankle for someone with a trans-tibial amputation. Our client’s ultimate goal is to break weightlifting paralympic records. Our design team developed a one DOF ankle that biomimetically assists him with a squatting exercise through semi-active torque modulation. The graphs show inconsistencies in ankle moment throughout the squat movement. His prosthesis is on his right ankle. Using our prototype, our client can keep his balance, as shown by the decrease in variance of the torque trajectories shown in the plots below. The blue and red lines in the plots below should converge after he has trained with it for the summer. The convergence would indicate whole-body force generation symmetry. We’ve added dynamic control of force return using sensors, actuators, and a microcontroller. The user controls the entire device via a Bluetooth app on their smartphone.

Our project received an Honorable Mention for the Tong Biomedical Design award and 3rd place in the UW campus-wide Tech B2B Innovation Program.

My teammate Hannah received her Master’s after further device tuning and more subject trials!

Mrazsko, H. X., Dekarske, J. T., and Adamczyk, P. G. (June 26, 2020). “Design of a Variable Stiffness Pneumatic Ankle Prosthesis With Self-Recharging for Weightlifting Exercise.” ASME. J. Med. Devices. September 2020; 14(3): 034501. https://doi.org/10.1115/1.4047493