Design, structural analysis and manufacture of transtibial prosthetic sockets with 3D printing

This project will cover how to design, validate and manufacture prostheses with 3D printing; specifically, transtibial prosthetic sockets. The project starts with a research on 3D printing and its applications, as well as 3D printing types and materials. Besides, the project covers a complete research on prostheses and its classification. Then, the project is focused specifically on transtibial prostheses, and its components and types are described. All components except the socket are available in the market as standard parts, and they just need to be properly selected to satisfy patients’ requirements. On the other hand, the socket must be completely designed and customized for each patient. For this reason, manufacturing prosthetic sockets with 3D printing technology brings a huge variety of advantages, which are carefully described in this project. Afterwards, a study of human movements and stump critical anatomical areas has been done. In addition, a kinematic and dynamic analysis of the human leg and socket has been carried out. With these specifications, an initial prosthetic socket has been designed with a CAD software chosen. When the initial socket has been designed, a validation and geometry iteration phase has been carried out. The suitable 3D printing material has been chosen, and a Finite Elements Analysis has been done with Ansys software. The maximum loads during a human gait cycle calculated in the dynamic analysis have been applied in the FE analysis. The objective of the FE analysis is to prove the maximum equivalent stress and deformations that the prosthetic socket can support without failure based on the ultimate strength of the material chosen. Geometry and thickness modifications of the socket have been needed to obtain the desired safety factor. After all these steps, the final socket has been designed, validated and 3D printed successfully. Finally, results obtained have been compared to traditional socket characteristics. A business case of prosthetic sockets manufacturing with 3D printing versus traditional manufacturing has been developed and a list of potential next steps has been defined.