A Novel Assistive Device for Lower Limb Prostheses

We have generated two prototypes that work together to improve the usability and accessibility of the pin-locking suspension system for lower-limb prostheses. We aim to address the needs of a patient population with limited hand dexterity and related issues such as vision impairment. Accordingly, the designs were created with a focus on ease of use, durability, and full compatibility with pin-lock systems currently used in the market. Our system consists of a device called PinAlign that mitigates the problem of pin misalignment, as well as a lever-like release mechanism called ReleaseAssist that eases pin disengagement and doffing. The mechanism of the PinAlign has been built to withstand forces well above those present in normal gait without the pin detaching. Specifically, we aim to achieve a force failure point during swing phase at least as high as existing pin lock systems, which fail at close to 580 N of force. To test the mechanical performance of our designs, we will conduct static tests to measure the failure point of the PinAlign under suspension and load-bearing forces experienced during gait. ReleaseAssist will be tested by evaluating its ability to push in the release button with the leg under different loads. Finally, to rate the performance of our design in the criterion of ease of use, the system incorporating both components will be evaluated through timed donning/doffing, measurements of the number of unsuccessful donning attempts, and a user questionnaire issued to amputee participants.