residual limb volume

People wearing a lower leg prosthesis often experience discomfort or pain during the day because of changes in socket fit. To solve this problem, we created a motor-actuated prosthetic socket that automatically maintains socket fit by continuous adjustment of the socket size. A proportional-integral (PI) control system is implemented to adjust socket size based on data collected from an inductive sensor embedded within the socket wall. The sensed distance is representative of limb-to-socket distance. Experiments on participants with transtibial limb amputation verify that the system properly maintains and responds to a change in set point to maintain socket fit. read more