Ambulation Control System Design for a Hybrid Knee Prosthesis

Area of Science:

• Biomedical Engineering
• Rehabilitation Engineering
• Prosthetics and Orthotics

Background:

• Transfemoral amputees require prosthetic knees to restore ambulation.
• Passive knees offer limited functionality, while active knees provide more powered assistance.
• Semi-active prosthetic devices aim to balance power usage and functionality.

Purpose of the Study:

• To develop and evaluate an ambulation control system for a lightweight Hybrid Knee prosthesis.
• To enable powered assistance for stair climbing while utilizing passive modes for other activities.
• To assess the accuracy of an intent recognition system for predicting active vs. passive control.

Main Methods:

• Development of a hybrid knee prosthesis control system.
• Implementation of an ambulation control strategy switching between powered and passive modes.
• Design and testing of an offline and online intent recognition system.
• Evaluation with one able-bodied user and one individual with transfemoral amputation.

Main Results:

• The hybrid knee system is designed for powered stair climbing and passive operation during level walking, inclines, and stair descent.
• Preliminary results demonstrate low error rates in predicting user intent for active or passive control.
• Successful intent recognition was shown in both able-bodied and transfemoral amputee participants.

Conclusions:

• The developed ambulation control system shows promise for enhancing prosthetic knee functionality.
• The hybrid approach offers a potential solution for energy-efficient prosthetic ambulation.
• Accurate intent recognition is crucial for seamless transitions between powered and passive prosthetic knee modes.