An Easy-to-Use Socket-Suspension System Monitor for Lower Limb Amputees

摘要

Prosthetic sockets and the related suspension systems play key roles in functional restoration for individuals with limb loss; a good fit of the socket-suspension systems (SSSs) is critical to avoid unexpected skin breakdown. However, maintaining a good fit between the limb and SSS is challenging due to daily volume changes in the residual limb. In clinical practice, the fit of the SSS is monitored only through haptic feedback from the user. While important, this subjective feedback is often unreliable and inaccurate. Several automatic SSS monitoring approaches have been proposed, but widespread adoption has been limited by related high costs and difficulty of use. To address these issues, we designed a wearable SSS monitor that can be adopted for any SSS using liners without requiring permanent modifications of the SSS. Using a tiny magnetic disk as a marker, we were able to monitor the relative displacement between the residual limb (represented by the liner) and the prosthetic socket along the proximal-distal direction using field orientation measurement sensors. We conducted bench tests to validate the high accuracy of the wearable SSS monitor and demonstrated the capability of tracking SSS fit changes during locomotion without permanent modification of the SSS.