Senior Design: Pressure Sensing Technology for Transtibial Prosthetics

This two-semester biomedical engineering capstone project is dedicated to solving a critical, persistent clinical challenge: the prevention of pressure injuries (ulcers, sores, and tissue breakdown) in individuals with transtibial (below-the-knee) amputations. Our initial ethnographic research identified a significant unmet clinical need stemming from the subjective nature of prosthetic socket fitting. Current clinical practice relies heavily on intermittent, costly, and often bulky pressure measurement systems, or simple trial-and-error based on patient comfort and visible skin redness. This lack of objective, real-time quantitative data leaves prosthetists without the necessary tools to make precise adjustments, leading to long-term patient discomfort, reduced mobility, and frequent, costly follow-up appointments.

Our team has begun to design a non-invasive, diagnostic solution: a Pressure Sensing Matrix. The core concept involves integrating sensors that can be incorporated into the prosthetic interface, specifically as a Prosthetic Sock. This approach ensures the sensor system causes minimal interference with the limb-socket fit while providing pressure mapping. In the current prototype phase, we are prioritizing data accuracy and rapid clinical use over wireless functionality. Our goal is that the sensor array is connected to a dedicated Data Acquisition (DAQ) system via a wired connection, which allows the prosthetist to view live visual pressure during sitting, standing, and required activities. This immediate, objective feedback is designed to guide the clinician in making precise adjustments, ultimately optimizing load distribution and mitigating localized pressure hotspots responsible for tissue damage.

As the Team Lead for this six-person project, I have guided the team from the Concept Generation and Requirements Definition phases into active Prototyping. This includes hands-on work with sensor selection, material testing, and the initial integration of sensors into fabric substrates. Our next steps involve rigorous Verification and Validation (V&V). We will conduct benchtop testing to verify the system's accuracy, durability, and biocompatibility, followed by crucial Clinical Validation under an IRB-approved protocol. This final stage will demonstrate the device's efficacy by showing its ability to objectively improve socket fit and enhance patient safety compared to existing subjective assessment methods.