Self-powered device for tibiofemoral force measurement in knee implant

摘要

A self-powered device that can be embedded within the knee implant to measure tibiofemoral forces is presented. This device can be used intraoperatively during the knee surgery or postoperatively through the implant lifetime. The twofold use of piezoceramic elements simultaneously as force sensors and power harvesters makes the device small enough to fit into the tibial component without increasing its thickness excessively. In this paper, we present the custom-designed tibial component developed to accommodate the double-function piezoceramics. In addition, we quantify experimentally the mean electric power harvested by these elements during one cycle of a simulated human walking. The power conditioning circuits and radiofrequency link needed for the function of this device is briefly addressed and will be fully discussed in a later paper.