A Primarily-Passive Knee Prosthesis with Powered Stance and Swing Assistance

Area of Science:

• Biomedical Engineering
• Rehabilitation Engineering
• Prosthetics and Orthotics

Background:

• Microprocessor-controlled knee prostheses (MPKs) offer advanced functionality for individuals with transfemoral amputation.
• Current MPKs primarily provide passive behavior, with limited powered assistance capabilities.
• There is a need for prosthetic devices that combine robust passive functionality with active powered support.

Purpose of the Study:

• To describe a novel knee prosthesis integrating passive and powered behaviors.
• To introduce an electronically-selectable two-speed transmission enabling dual-mode functionality.
• To present a control system managing adaptive torque for various gait phases and activities of daily living (ADLs).

Main Methods:

• Development of a unique electronically-selectable two-speed transmission.
• Implementation of a control system with six adaptive states for gait phase management.
• Experimental evaluation on an individual with transfemoral amputation comparing performance to a commercial MPK.

Main Results:

• The novel prosthesis demonstrated passive behavior comparable or superior to a state-of-the-art MPK.
• The device successfully provided powered stance and swing assistance.
• The integrated system effectively managed adaptive torque behaviors across different gait states.

Conclusions:

• The described knee prosthesis successfully combines advanced passive functionality with powered assistance.
• The dual-mode capability and adaptive control system offer a promising advancement for transfemoral amputees.
• This technology has the potential to improve mobility and quality of life for prosthetic users.