Emulator helps iteration of prosthetic lower leg

Stanford University mechanical engineers used the emulator to develop a ‘tripod foot’ that responds to rough terrain by actively shifting pressure between three different contact points.

Graduate student Vincent Chiu, postdoctoral researcher Alexandra Voloshina and Steven Collins, an associate professor of mechanical engineering and a member of Stanford Bio-X describe the construction and first tests of their prosthetic emulator in a paper published in IEEE Transactions on Biomedical Engineering.

“Prosthetic emulators allow us to try lots of different designs without the overhead of new hardware,” said Collins. “Basically, we can try any kind of crazy design ideas we might have and see how people respond to them.”

To make rougher terrain more manageable for lower leg prosthetics, the team looked at a tripod with a rear-facing heel and two forward-facing toes. Outfitted with position sensors and motors, the foot could adjust its orientation to respond to varying terrain, much as someone with an intact foot could move their toes and flex their ankles to compensate while walking over rough ground.