An Open-Source Topology Optimization Framework for ISO 10328-Compliant, Image-Driven Prosthetic Foot Design

Prosthetic foot design remains relatively rudimentary, as high-strength materials such as metals and carbon-fiber composites limit fabrication methods and design freedom. Conventional approaches rely on size optimization of simple geometries, which do not fully capture anatomical boundaries or natural force transmission through the foot. Here, we adopt an initial design domain derived from the side profile of an actual human leg, providing a more anatomically consistent and patient-specific basis for topology optimization. We present a fully automated, open-source framework for prosthetic foot design that incorporates ISO 10328 boundary conditions to ensure reliability. Topology optimization is used to determine the optimal material distribution, followed by geometry smoothing for 3D printing. A key outcome is a universal design curve obtained through nondimensionalization: ${\mathrm{CEL}}_f/F^2$ , linking material stiffness, foot size, and patient weight. This enables direct design selection without rerunning optimization for each patient, cutting out design time and cost. Overall, the framework provides a fast, scalable approach to personalized prosthetic design.