Measurement of Soft Tissue Artifacts in Human Motion Analysis

• Main Authors: Po-Yuan Chen, 陳柏元
• Other Authors: Tung-Wu Lu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/09419246859853494386

碩士 === 國立臺灣大學 === 醫學工程學研究所 === 96 === The human motion analysis is essential for assessing musculoskeletal & joint disease or injury. Infrared stereophotogrammetry is currently the most common non-invasive method for the measurement of human motion. It is to determinate the spatial position and to get the understanding human body extremity section movements. Soft tissue artifacts (STA) are the most important errors in this method. If the STA are not able to be handled effectively, it will further create the deviation of the definition of the extremity section coordinates systems. The new method used the three dimension models (reconstructed from serial computer tomography images or the computer-aided design model) to register with two-dimensional (2D) fluoroscopic images during motion. Motion data of the markers on the extremity were also measured simultaneously using the motion analysis system. With the exact 3D position and orientation of the bones during motion, the STA can be determined using coordinates transformation of the skin markers. Hence, the purposes of this study were to quantify the STA, and to obtain the errors of the joint angles and moment. The angle calculated by fore-arm coordinates system was not sensitive during pronation/supination motion. It can’t totally exhibit the true motion and it will cause huge errors when we analyzed the upper-limb motion. Therefore, it can provide a set of markers to avoid soft tissue artifact. In addition, there are large errors in joint angles and moments in the sagittal plane. In this study, we utilized complete lower-limb free body analysis that will be more faultless than previous study which only used the ground reaction force and the knee joint axis to calculate the joint moment. In the future, the method we develop will be adopted in other joint components and be extended in studying various kinds of diseases. Furthermore, we can study the compensation methods and the effects of coordinate system definition by soft tissue artifact.