Annu Int Conf IEEE Eng Med Biol Soc. 2015 Aug;2015:2737-40. doi: 10.1109/EMBC.2015.7318958.
Malposition of the acetabular and femoral component has long been recognized as an important cause of dislocation after total hip replacement (THR) surgeries. In order to help surgeons improve the positioning accuracy of the components, a visual-aided system for THR surgeries that could estimate orientation and depth of femoral component is proposed. The sensors are fixed inside the femoral prosthesis trial and checkerboard patterns are printed on the internal surface of the acetabular prosthesis trial. An extended Kalman filter is designed to fuse the data from inertial sensors and the magnetometer orientation estimation. A novel image processing algorithm for depth estimation is developed. The algorithms have been evaluated under the simulation with rotation quaternion and translation vector and the experimental results shows that the root mean square error (RMSE) of the orientation estimation is less then 0.05 degree and the RMSE for depth estimation is 1mm. Finally, the femoral head is displayed in 3D graphics in real time to help surgeons with the component positioning.
髋臼和股骨组件位置不当长期以来一直被认为是全髋关节置换（THR）手术后脱位的一个重要原因。为了帮助外科医生提高组件的定位精度，提出了一种用于THR手术的视觉辅助系统，该系统可以估计股骨组件的方向和深度。传感器固定在股骨假体试验件内部，棋盘格图案印在髋臼假体试验件的内表面。设计了一种扩展卡尔曼滤波器来融合来自惯性传感器的数据和磁力计方向估计。开发了一种用于深度估计的新型图像处理算法。这些算法在使用旋转四元数和平移向量的模拟下进行了评估，实验结果表明方向估计的均方根误差（RMSE）小于0.05度，深度估计的RMSE为1毫米。最后，股骨头以3D图形实时显示，以帮助外科医生进行组件定位。
