A pressure and shear sensing liner for prosthetic sockets

Interface pressures are closely related to the comfort and fit of a lower-limb prosthetic socket and clinicians and researchers are interested in monitoring these loads. In particular, shear stresses at the socket/liner interface are indicative of important fit characteristics but are difficult to measure in situ. We have developed an elastomeric liner with sixteen integrated pressure and shear sensors, along with necessary wiring and data acquisition electronics. The sensors measure three-axis pressures using optical emitter/detector pairs coupled with transparent and opaque elastomeric layers. The liner has similar properties to those typically used in clinical practice. The system was tested on a single amputee subject during several sit/stand/walk cycles.