A compact system to assist clinician-guided offloading of high-pressure diabetic foot regions. Automatically detects high-pressure regions associated with ulcer risk and relieves pressure in real time.
Over 537 million people worldwide live with diabetes, expected to reach 643 million by 2030. The epidemic shows no sign of slowing.
Diabetes damages nerves, preventing patients from detecting pain or pressure. 19% to 34% of people with diabetes develop a foot ulcer during their lifetime.
Orthon's goal: a compact, wearable system that automatically detects foot ulcer hotspots and relieves pressure — no clinical visit needed.
The pressure sensing insole continuously maps plantar pressure across the foot. Sensors flag the forefoot when readings exceed 40% of total forefoot pressure, and the heel when readings exceed 60% of total heel pressure — divided by sensor count.
A custom PCB microcontroller runs: Low-pass Moving Average pressure filtering, Pressure Mapping by Inverse Distance Weighting (O(h²) error), Descending-Priority Greedy Selector for high-pressure spots, and closed-loop Module PI Control.
Offloading modules receive the control signal and physically raise or lower their TPU platform via a Nitinol lock ring mechanism. Each pressure spike triggers a corresponding rise in offloading distance — the actuator drops to redistribute load.
Pressure relief is fed back to the patient in real time. Orthon successfully demonstrates real-time closed-loop pressure offloading at both the forefoot and heel — validating full system feasibility without physician intervention.
Magnetorheological Fluid (MRF) consists of iron filings suspended in a lubricating compressible oil. Its stiffness responds dynamically to applied magnetic fields — becoming fully rigid under activation and soft when deactivated.
The Nitinol Lock Ring Module uses a flexible nitinol-embedded TPU and ASA snap ring. When power is applied the lock ring expands, allowing the platform to fall into a spring-supported offloading state — transitioning from 15mm to 12mm height.
| Requirement | Description | Status |
|---|---|---|
| Pressure Offloading | Offload plantar pressure by 30–50% at flagged zones | Validated ✓ |
| Structural Integrity | Withstand 800–1200 kPa of plantar pressure during normal gait | Validated ✓ |
| Form Factor | All components fit within a 20 mm height constraint inside the insole | Validated ✓ |
| Gait Detection | Identify heel strike, midstance, and toe liftoff phases of gait cycle | Validated ✓ |
| Adaptive Support | Transition between offloading and rigid support states dynamically | Validated ✓ |
| Threshold Algorithm | Flag forefoot at >40% total forefoot pressure; heel at >60% total heel pressure, divided by sensor count | Implemented ✓ |
Completed literature review, competitive analysis, and SolidWorks designs for Nitinol module. Full electronics flow diagram developed. FEA pressure distribution simulations characterize module behavior. All requirements documented and reviewed with clinical advisor Dr. Elhaddad.
Full assembly of insole prototype with Nitinol lock ring modules and custom PCB. Bench testing confirmed real-time closed-loop pressure offloading at forefoot and heel. Each excess pressure spike produces a corresponding rise in offloading distance. System feasibility validated across recorded tests.
Transition to a compact, fully wearable device. Miniaturize all electronics into the insole form factor with no external components required.
Develop Virtual Twin software. Conduct trials with diabetes and post-surgical cohorts. Evaluate regulatory pathway toward Class II device classification.
Orthon successfully demonstrates real-time closed-loop pressure offloading at both the forefoot and heel across all recorded tests.
Results validate the full system architecture — sensing, processing, and actuation all working in concert within the insole form factor.
Dr. Alyssa Taylor, Dr. Sean Collignon, Nagarjun Bhat, Greg Hainline, and the DIB Staff for their guidance and support throughout this project.
University of California, San Diego · BENG 207 Medical Device Design 1 · Winter 2026
The Orthon team presented at UCSD's Bioengineering Design Day 2026, demonstrating real-time closed-loop pressure offloading to faculty, clinicians, and fellow students.
The team with the Orthon poster and live prototype demonstration setup.
Demonstrating real-time pressure mapping and module offloading to attendees and judges.
Team M2 at the poster session, Spring 2026.