Legget M E, Martin R W, Sheehan F H, Bashein G, Bolson E L, Li X N, Leotta D, Otto C M
Department of Medicine, University of Washington, Seattle 98195-6422, USA.
J Am Soc Echocardiogr. 1996 May-Jun;9(3):266-73. doi: 10.1016/s0894-7317(96)90139-x.
Three-dimensional (3D) reconstruction from a single esophageal scanning position requires a stable relationship between the probe and the heart. The purpose of this study was to examine the movement of a transesophageal echocardiographic probe during 3D image acquisition. A new dual-axis multiplane probe was used that includes a miniature (6 x 6 x 9 mm) magnetic sensor in the tip. The sensor identifies the probe's 3D position and 3D orientation in space with respect to the location of a magnetic field generator placed beneath the subject. In vivo 3D scanning was performed in five anesthetized, ventilated dogs, with positional determinations acquired every 66 msec. Probe movement was estimated by computing the deviations of each x, y, and z position and orientation determination, compared with the average values during each 3D scan or cardiac cycle. Ten 3D scans were analyzed, involving 263 cardiac cycles and 2328 determinations. The range and SD of the translational movement of the transducer were 2.3 and 0.8 mm, 1.7 and 0.5 mm, and 2.4 and 0.7 mm in x, y, and z directions, respectively, during 3D scanning. Translational movement was more dominant than was rotational movement. Misregistration of three-dimensional reconstructions may be due to subtle probe movement. The ability to monitor probe movement may be helpful in optimizing 3D data sets.
从单一食管扫描位置进行三维（3D）重建需要探头与心脏之间保持稳定关系。本研究的目的是检查经食管超声心动图探头在三维图像采集过程中的移动情况。使用了一种新型双轴多平面探头，其尖端包含一个微型（6×6×9毫米）磁传感器。该传感器可根据置于受试者下方的磁场发生器的位置，识别探头在空间中的三维位置和三维方向。对五只麻醉、通气的犬进行了体内三维扫描，每66毫秒获取一次位置测定值。通过计算每次三维扫描或心动周期中每个x、y和z位置及方向测定值与平均值的偏差，估计探头移动情况。分析了十次三维扫描，涉及263个心动周期和2328次测定。在三维扫描过程中，换能器在x、y和z方向上平移运动的范围和标准差分别为2.3和0.8毫米、1.7和0.5毫米以及2.4和0.7毫米。平移运动比旋转运动更显著。三维重建的配准错误可能是由于探头的细微移动所致。监测探头移动的能力可能有助于优化三维数据集。
