Research and Development of the Intelligently-Controlled Prosthetic Ankle Joint

Abstract

The purpose of this study is to develop a prosthetic ankle joint intelligently controlled by specially designed linear MR (Magneto-Rheological) brake. MR fluid changes its rheology depending on the intension of an applied magnetic field. The brake using MR fluid (we call it MR brake) has a simple structure and can control its braking force with a low voltage. Prosthesis users often tumble because they don't have dorsiflexor , so that we propose putting MR brake taking the place of dorsiflexion. We hope that prosthesis users can walk more naturally and smoothly by use of developed intelligent prosthetic ankle joint with MR brake. We developed a prototype of it and evaluated it with walking experiments before. But there were some problems with the prototype in terms of hardware and experimental environments. Therefore we have developed a 2nd prototype of the intelligent prosthetic ankle joint with the MR brake, which was improved considering previous problems, and then we have carried out the walking experimental evaluation of it.

Biomechanical analysis of ramp ambulation of transtibial amputees with an adaptive ankle foot system

“…The underlying assumption of these new prosthetic ankles is that gait on stairs and on ramps could already be improved by modifying the ankle angle through motors [3][4][5] or springs [6].…”

Composite active disturbance rejection robust control for a prototype of an active damping artificial ankle prosthesis

“…is the state of the electromechanical system. For all the three stages, x a = q and x b = d dt q where q was defined in (2). Indeed, we identify the states as x a = q sw and x b = dq sw dt for this stage where q sw represents the states evolution during the swinging.…”

“…These devices have been improved in the search of emulating the basic movements concerning gait cycle, standing as well as sitting tasks. Many functional devices have been introduced in the context of robotics technologies for ankle prosthesis (see [1][2][3][4][5], among others).…”

Experimental evaluation of an assistive knee brace with magnetorheological actuator

“…Jonsdottir et al further studied the parameters of this MR brake [11]. Li et al developed an MR brake used in prosthetic ankle joint to make the user walk smoothly [12]; but more work is needed to put this system into practical use.…”