This study aims to enhance hygiene and structural performance in additively manufactured (AM) below-knee prosthetic sockets by optimizing ventilation and structural integrity through advanced design methodologies, including topology optimization (TO) and design for additive manufacturing (DfAM).
A transtibial prosthetic socket was digitally modeled from image data of the residual limb of an amputee and fabricated using acrylonitrile butadiene styrene (ABS) material using fused deposition modeling. TO and DfAM rules were applied to achieve the multi-objective design of ventilation, weight reduction and structural integrity by introducing geometric discontinuities. The level of this achievement was evaluated through finite element analysis (FEA) and mechanical testing using a novel lobe bending test.
This study found that TO significantly reduced stress concentrations and improved the strength-to-weight ratio of the socket. Mechanical testing revealed a critical failure load of 918.5 N, validated by FEA, which indicated peak stresses of 37.91 MPa. A 5 mm thick socket with circular discontinuities demonstrated enhanced ventilation and mechanical resilience.
The focus on ABS material and specific socket designs may limit the generalizability of findings to other materials and designs.
The optimized socket design provides a cost-effective, high-performance solution for improving comfort and durability in below-knee prosthetic sockets within AM applications.
This research introduces innovative testing methods, including the lobe bending test and uses advanced optimization techniques, addressing challenges in ventilation and mechanical performance. The insights gained are valuable for future prosthetic socket design advancements.
