Dumas R, Cheze L
Université de Lyon, F-69622, Lyon, France.
J Biomech. 2009 Sep 18;42(13):2214-7. doi: 10.1016/j.jbiomech.2009.06.006. Epub 2009 Jul 28.
Several compensation methods estimate bone pose from a cluster of skin-mounted makers, each influenced by soft tissue artifact (STA). In this study, linear 3D interpolation and approximation methods (affine mapping, Kriging and radial basis function (RBF)) and the conventional singular value decomposition (SVD) method were examined to determine their suitability for STA compensation. The ability of these four methods to estimate knee angles and displacements was compared using simulated gait data with and without added STA. The knee angle and the displacement estimates of all four methods were similar with root-mean-square errors (RMSEs) near 1.5 degrees and 4mm, respectively. The 3D interpolation and approximation methods were more complicated to implement than the conventional SVD method. However, these non-standard methods provided additional geometric (homothety, stretch) and time functions that model the deformation of the cluster of markers. This additional information may be useful to model and compensate the STA.
有几种补偿方法可从一组贴在皮肤上的标记点估计骨骼姿态，每个标记点都受软组织伪影（STA）影响。在本研究中，对线性三维插值和逼近方法（仿射映射、克里金法和径向基函数（RBF））以及传统的奇异值分解（SVD）方法进行了研究，以确定它们对STA补偿的适用性。使用添加和未添加STA的模拟步态数据，比较了这四种方法估计膝关节角度和位移的能力。所有四种方法的膝关节角度和位移估计值相似，均方根误差（RMSE）分别接近1.5度和4毫米。三维插值和逼近方法比传统SVD方法实施起来更复杂。然而，这些非标准方法提供了额外的几何（相似性、拉伸）和时间函数，可对标记点簇的变形进行建模。这些额外信息可能有助于对STA进行建模和补偿。
