HuMotech Enables Real-Time Testing and Assessment of Prosthetic Designs

"Ansys Mechanical tools have greatly improved the accuracy of our finite element analysis (FEA) simulations and the efficiency of our computer-aided engineering workflow, enabling us to improve our product’s performance. In the past, we spent a lot of time working around the limitations of our FEA tools, but working with Ansys simulation software is empowering — we’re always impressed with its breadth of features, robustness and ease of use."

— Josh Caputo, President / CEO HuMoTech

Introduction

Designing and prescribing lower-limb prostheses is hindered by uncertainty in both research and clinical settings. Researchers struggle with the high cost and time requirements of prototyping, with no way to pre-test specific parameters. Prosthetists and patients cannot efficiently “test drive” prosthetic devices, which may result in higher costs and less than ideal quality of life. HuMoTech’s emulation solution tackles all these challenges.

Challenges

In the development of a robotic prosthesis, mechanical FEA is not optional — it is imperative. In our design work, we often face open-ended requirements, such as maximizing or minimizing a part’s stiffness or weight. Users’ hopes and dreams for prosthetics are constantly pushing the boundaries of what is possible. Simulation is the only method that cuts through the high cost of trial-and-error learning.

Engineering Solution

HuMoTech’s engineers used the following features of Ansys Mechanical to overcome their challenges:

• Full assembly simulations considering preloads to allow for more realistic results.
• Mesh control and refinement to speed up simulation time.
• Contact definitions to improve realistic stresses between parts. This has been especially useful for parts with large elastic deformations.
• Fatigue analysis to improve estimates of the lifetime of system components and inform users when parts should be serviced.

Benefits

• 25% weight reduction of the prosthesis end-effector, which allows our device to more accurately emulate a wider range of prosthetic devices.
• Increased productivity when setting up and running simulations, allowing us to do more thorough analyses.
• Higher confidence that parts will be robust in the harshest conditions over years of use.