A Control Method for Transtibial Prostheses with Bilateral Leg Data

Micro-controlled lower limb prosthetic devices typically employ onboard sensors on the amputated side of the user's body to generate control patterns. However, balanced ambulation in a healthy subject requires synchronized neural control to facilitate appropriate positioning and orientation of both limbs. Building upon this idea, this study introduces a control architecture that utilizes information acquired from both limbs using only two inertial measurement units (one placed on the left shank, and one placed on the right thigh) to generate the control commands for a transtibial prosthesis prototype clamped to a table-top. Multiple trials were performed with a healthy subject walking on level ground at different speeds and undertaking an obstacle avoidance task. The results of the experiments suggest that incorporating data from each side provides comprehensive information about the limb's positions and orientations, thereby enabling a controller that can handle actuation timing and assist in precise prosthesis control through an understanding of the user's gait states.