Introduction
At Hodgson Group, we are continuing to modernize prosthetic care through our ongoing partnership with Simon Fraser University’s (SFU) Additive Manufacturing Laboratory. Our latest research, recently published in the journal Biosensors and Bioelectronics, details a “sensing-to-fabrication” workflow that uses real-time 3D pressure mapping to optimize prosthetic socket design. By integrating wearable sensors with advanced 3D-printed lattice structures, we can now customize a socket’s mechanical properties to match a patient’s specific movement patterns.
Link: https://www.sciencedirect.com/science/article/pii/S0956566326001922?via%3Dihub
Methods
Our digital workflow replaces traditional manual methods with a data-driven approach:
- Wearable Sensing: We utilized a liner embedded with 3D-printed, origami-inspired capacitive sensors to capture dynamic pressure at the limb-socket interface.
- Activity Testing: A volunteer with a transfemoral amputation performed activities including standing, walking on flat ground, and descending ramps while data was recorded.
- Advanced Materials: The system was fabricated using TPU NinjaTek Cheetah (95A) for structural elements and NinjaTek Eel (90A) for the flexible dielectric sensor components.
- Density-Graded Infill: We processed pressure data to create a 3D map that dictated the density of internal lattice structures, focusing on Gyroid, Diamond, and Neovius designs.
Results
The performance data highlighted why personalized design is so critical:
- Peak Forces: The study identified ramp descent as the most demanding activity, with peak pressures reaching up to 7500 kPa.
- Energy Absorption: Finite Element Analysis (FEA) showed that our density-graded Gyroid structure absorbed 1600% more energy during standing and 1290% more energy during walking compared to standard solid infills.
- Optimized Comfort: The Gyroid design was identified as the most efficient at redistributing loads and providing mechanical cushioning among the tested geometries.
Discussion
By using 3D pressure mapping as a direct design input, we can strategically cushion high-pressure zones that often lead to complications like pain or skin ulcers. This research addresses the need for a reproducible, patient-specific workflow that moves away from reliance on manual expertise toward a more data-driven approach. While this study is a preliminary proof-of-concept, the results demonstrate a significant potential for creating more functional and comfortable prostheses.
Conclusion
The collaboration between Hodgson Orthopedic Group and SFU has established a new standard in flexible and adaptive prosthetic technology. By combining 3D pressure mapping with field-driven design, we have created a pathway for more comfortable and functional 3D-printed prosthetic sockets. We look forward to extending this system to other amputation levels and exploring its use in broader clinical and biomechanical research.
