Biomechanics and Implant Design

Biography

Biography: Ann M Simon

Abstract

Lower limb amputation affects an individual’s ability to efficiently perform activities of daily living. For individuals with high levels of amputation, such as a trans-femoral amputation, this impact can be much greater since they must rely on a mechanical substitute for their knee and ankle joints. Powered prosthetic legs are an emerging category of devices that are becoming commercially available but their control needs to be further refined for clinical viability. This talk will highlight several of the advances we have made to provide users with natural, intuitive, and robust control of a powered prosthesis. For example, we developed a new user-modulated control strategy that enables improved control of powered knee-ankle prosthesis during sit-to-stand movements. Allowing transfemoral amputees more control over the timing and rate of knee and ankle power generation enabled standing and sitting with their weight distributed more equally between limbs. To provide seamless transitions between weight-bearing activities, we created an ambulation mode intent recognition system that incorporates neural information in combination with mechanical sensors. Electromyographic (EMG) signals, or muscle activity patterns, have been used for decades to control upper limb prostheses and, for lower limb applications, can provide data on how a person intends to use their device (e.g., whether the individual intends to walk or climb stairs).The successful implementation of these control strategies is an exciting step towards providing improved control of a powered prosthesis, potentially making ambulation and other activities of daily living easier for trans-femoral amputees.