Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive N.W., Calgary, AB, T2N 1N4, Canada.
Department of Mechanics and Robotics, University of Duisburg-Essen, Forsthausweg 2, 47057, Duisburg, Germany.
Med Biol Eng Comput. 2023 Jul;61(7):1783-1793. doi: 10.1007/s11517-023-02813-2. Epub 2023 Mar 14.
Highspeed Biplanar Videoradiography (HSBV) permits recording of 3D bone movements with sub-millimeter precision. 2D-3D registrations are performed to quantify bone movements, providing a series of affine transformation matrices (ATMs). These registrations may result in alignment errors that produce inaccurate kinematics. Smoothing techniques can be applied to the ATMs to reduce these inaccuracies. Which techniques are best for this application remain unknown. The purpose of this study was to investigate the performance of six smoothing techniques on ATMs obtained from HSBV. Performance was assessed by measuring the accuracy of three reference finite helical axis (rFHA) measures during a turntable rotation: orientation, dispersion, and rotation speed difference (RSD = rFHA RS-turntable RS). A 3D printed femur and tibia were mounted to the turntable and rotations recorded with HSBV. The rFHA was calculated for the bones using each smoothing technique and ranked using a Friedman test. The relative percent change to the unsmoothed data was reported. A spline filter with outlier removal (SPOUT) was ranked the best technique, producing the most accurate RSDs for the femur (-79.64%) and tibia (-70.59%). SPOUT was the top performing smoothing technique. Further investigations using SPOUT are required for in-vivo human movements.
高速双平面影像（HSBV）可记录具有亚毫米精度的 3D 骨骼运动。通过二维到三维配准来量化骨骼运动，提供一系列仿射变换矩阵（ATMs）。这些配准可能会导致对齐误差，从而产生不准确的运动学。可以将平滑技术应用于 ATMs 以减少这些不准确性。哪种技术最适合这种应用仍然未知。本研究的目的是研究六种平滑技术在 HSBV 获得的 ATMs 上的性能。通过测量在转台旋转过程中三个参考有限螺旋轴（rFHA）测量的准确性来评估性能：方位，分散度和转速差（RSD=rFHA RS-转台 RS）。将 3D 打印的股骨和胫骨安装到转台上，并使用 HSBV 记录旋转。使用每种平滑技术为骨骼计算 rFHA，并使用 Friedman 检验对其进行排名。报告相对于未平滑数据的相对百分比变化。带有异常值去除的样条滤波器（SPOUT）的排名最高，为股骨（-79.64％）和胫骨（-70.59％）产生最准确的 RSD。SPOUT 是表现最佳的平滑技术。需要进一步使用 SPOUT 对体内人体运动进行研究。
