Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, T6G 2B7, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, T6G 2V2, Canada.
Department of Pediatrics, University of Alberta, Edmonton, Alberta, T6G 1C9, Canada.
Med Eng Phys. 2024 Sep;131:104221. doi: 10.1016/j.medengphy.2024.104221. Epub 2024 Aug 5.
Tracking the position and orientation of a two-dimensional (2D) ultrasound scanner to reconstruct a 3D volume is common, and its accuracy is important. In this study, a specific miniaturized electromagnetic (EM) tracking system was selected and integrated with a 2D ultrasound scanner, which was aimed to capture hip displacement in children with cerebral palsy. The objective of this study was to determine the optimum configuration, including the distance between the EM source and sensor, to provide maximum accuracy. The scanning volume was aimed to be 320 mm × 320 mm × 76 mm. The accuracy of the EM tracking was evaluated by comparing its tracking with those from a motion capture camera system. A static experiment showed that a warm-up time of 20 min was needed. The EM system provided the highest precision of 0.07 mm and 0.01° when the distance between the EM source and sensor was 0.65 m. Within the testing volume, the maximum position and rotational errors were 2.31 mm and 1.48°, respectively. The maximum error of measuring hip displacement on the 3D hip phantom study was 4 %. Based on the test results, the tested EM system was suitable for 3D ultrasound imaging of pediatric hips to assess hip displacement when optimal configuration was used.
跟踪二维 (2D) 超声扫描仪的位置和方向以重建 3D 体积是常见的，其准确性很重要。在这项研究中，选择了一种特定的小型电磁 (EM) 跟踪系统，并将其与 2D 超声扫描仪集成，旨在捕获脑瘫儿童的臀部位移。本研究的目的是确定最佳配置，包括 EM 源和传感器之间的距离，以提供最大的准确性。扫描体积的目标是 320mm×320mm×76mm。通过比较 EM 跟踪与运动捕捉相机系统的跟踪，评估 EM 跟踪的准确性。静态实验表明，需要预热 20 分钟。当 EM 源和传感器之间的距离为 0.65m 时，EM 系统提供了最高的精度，为 0.07mm 和 0.01°。在测试体积内，最大位置和旋转误差分别为 2.31mm 和 1.48°。在 3D 髋部模型研究中，测量髋部位移的最大误差为 4%。基于测试结果，当使用最佳配置时，所测试的 EM 系统适用于儿科髋关节的 3D 超声成像，以评估髋部位移。
