Mechanical Testing of Synthetic Femurs: Measurement of the Spatial Orientation by Real-Time Video Tracking

In this paper a real-time video tracking system that allows an accurate measurement of the spatial positioning of the femur in the testing rig is presented. The developed method relies on drawing patterns of optical markers on two different femur surfaces and on tracking them in real-time by means of two video acquisition systems. A dedicated object tracking software has been developed to perform linear regression of points positioned along two reference lines and to provide the actual angle in either of two different femoral planes. Preliminary results reported in this study have shown that the spatial orientation of the femur in the testing device may significantly affect either the deflection of the femoral head and the strain distribution in the diaphysis.