Robotic prosthesis that maintains flexion posture.

Area of Science:

• Biomedical Engineering
• Robotics
• Rehabilitation Technology

Background:

• Lower limb amputations are increasing, with above-knee amputations being the most common type.
• Current above-knee prostheses with artificial knee and ankle joints cater to various activity levels, primarily focusing on walking.
• Existing prosthetic knee joints lack specific designs for stabilizing the standing action, particularly when the knee is slightly flexed.

Purpose of the Study:

• To develop a robotic prosthesis that provides stability during both normal walking and standing.
• To address the unmet need for assistive devices that support the standing action after amputation.
• To create a prosthetic knee joint capable of reproducing natural flexion-extension motion.

Main Methods:

• Development of a robotic prosthesis incorporating a ratchet mechanism for the knee joint.
• Electronic control of the ratchet mechanism's claw movement using a finite state machine and state transition model.
• Evaluation of the developed robotic prosthesis through a walking experiment with a healthy participant.

Main Results:

• The developed robotic prosthesis successfully reproduced the knee's flexion-extension motion.
• The electronic control system, based on a finite state machine, was implemented for the ratchet mechanism.
• Experimental results demonstrated the effectiveness of the robotic prosthesis in providing stability during walking.

Conclusions:

• The developed robotic prosthesis offers enhanced stability for both standing and walking.
• The integration of a ratchet mechanism and electronic control presents a promising approach for advanced prosthetic knee joints.
• This study lays the groundwork for future assistive devices designed for a wider range of everyday activities beyond walking.