A Joint-Constraint Model-Based System for Reconstructing Total Knee Motion
A Joint-Constraint Model-Based System for Reconstructing Total Knee Motion
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DOI：
10.1109/tbme.2013.2278780
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发表时间：
2014-01-01
影响因子：
4.6
通讯作者：
Sun, Yung-Nien
中科院分区：
文献类型：
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作者：
Chen, Hsin-Chen;Wu, Chia-Hsing;Sun, Yung-Nien
了解膝关节运动是研究膝关节疾病原因的必要条件。本文提出了一种基于关节约束模型的二维三维配准系统，用于全膝关节运动重建。所提出的模型包含骨几何形状和关节机制，首先从多姿态磁共振进化图像构建。然后，将模型的骨段分层地注册到记录膝关节活动的给定单平面透视视频的每一帧。使用改进的倒角匹配算法迭代优化骨骼姿势，以产生最适合底层透视图像的模拟x线片。与传统的配准方法不同，本文提出的股胫和髌股关节模型在配准过程中适当地保持了股骨、胫骨和髌骨之间的关节。因此，我们可以获得一系列记录的膝关节姿势，显示平滑和合理的生理运动模式。该系统还提供关节空间插值，以密集地生成运动动画的中间姿态。通过计算机仿真、动物尸体和活体膝关节试验验证了该方法的有效性。股骨、胫骨和髌骨的靶位平均配准误差小于1.5 mm。特别是，在动物尸体评估中实现了小的面外配准误差[小于1毫米（平移）和2度（旋转）]。
Comprehending knee motion is an essential requirement for studying the causes of knee disorders. In this paper, we propose a new 2-D-3-D registration system based on joint-constraint model for reconstructing total knee motion. The proposed model that contains bone geometries and an articulated joint mechanism is first constructed from multipostural magnetic resonancevolumetric images. Then, the bone segments of the model are hierarchically registered to each frame of the given single-plane fluoroscopic video that records the knee activity. The bone posture is iteratively optimized using a modified chamfer matching algorithm to yield the simulated radiograph which is the best fit to the underlying fluoroscopic image. Unlike conventional registration methods computing posture parameters for each bone independently, the proposed femorotibial and patellofemoral joint models properly maintain the articulations between femur, tibia, and patella during the registration processes. As a result, we can obtain a sequence of registered knee postures showing smooth and reasonable physiologic patterns of motion. The proposed system also provides joint-space interpolation to densely generate intermediate postures for motion animation. The effectiveness of the proposed method was validated by computer simulation, animal cadaver, and in vivo knee testing. The mean target registration errors for femur, tibia, and patella were less than 1.5 mm. In particular, small out-of-plane registration errors [less than 1 mm (translation) and 2 degrees (rotation)] were achieved in animal cadaver assessments.