User‐adaptive control of a magnetorheological prosthetic knee

Abstract

A magnetorheological knee prosthesis is presented that automatically adapts knee damping to the gait of the amputee using only local sensing of knee force, torque, and position. To assess the clinical effects of the user-adaptive knee prosthesis, kinematic gait data were collected on four unilateral trans-femoral amputees. Using the user-adaptive knee and a conventional, non-adaptive knee, gait kinematics were evaluated on both affected and unaffected sides. Results were compared to the kinematics of 12 age, weight and height matched normals. We find that the useradaptive knee successfully controls early stance damping, enabling amputee to undergo biologically-realistic, early stance knee flexion. These results indicate that a useradaptive control scheme and local mechanical sensing are all that is required for amputees to walk with an increased level of biological realism compared to mechanically passive prosthetic systems.

Conception, design and development of a low-cost intelligent prosthesis for one-sided transfemoral amputees

“…Most of the recent developments in gait control for above-knee prosthesis are based on instrumented shoes coupled to the prosthesis, as reported by Bar et al (1983), Herr and Wilkenfeld (2003) and Kapti and Yucenur (2006). Compared to our approach, which is based on the echo control, when the load sensors are installed on the prosthesis foot, there are limitations for cyclic and symmetric patterns and the use for only unilateral amputees.…”

“…By utilizing specific programs and sensor information, these prostheses may result in a more natural gait (Aaron et al, 2006;Sup et al, 2008;Herr and Wilkenfeld, 2003;Johansson et al, 2005;Kahle et al, 2008;Kapti and Yucenur, 2006;Laferrier and Gailey, 2010). The main differences in the design of these prostheses are in their damping systems because an adequate damping allows for fast transitions in stride velocity, which increases the autonomy of the amputee.…”

Biomechanical conceptual design of a passive transfemoral prosthesis

“…• controlled by means of internal, intrinsically passive, actuators -These prostheses use external power to adapt their dynamics to different gait pattern. For example, in [2] and [3], the dynamical behavior of the prosthesis during walking relies on the control of a magnetorheological damper, which produces the required breaking torque for the knee joint.…”

Adapting to change : influence if a microprocessor-controlled prosthetic knee on gait adaptations

“…3,6 In most commercially available NMPKs early stance knee flexion is not possible. [7][8][9][10] Allowing early stance prosthetic knee flexion would require high knee damping. This high level of damping would restrict prosthetic knee flexion later on in the gait cycle when the knee has to be sufficiently flexed for forward progression of the swing leg.…”