Meyer S A, Wolf P D
Department of Biomedical Engineering, Duke University, Durham, NC 27708-0281, USA.
IEEE Trans Biomed Eng. 1997 Nov;44(11):1061-7. doi: 10.1109/10.641333.
This paper describes a technique for tracking the three-dimensional (3-D) position of a cardiac catheter using sonomicrometry and the mathematical method of multidimensional scaling (MDS). Sonomicrometry is used to measure the distances between ultrasonic transceivers. MDS is then used to calculate the 3-D coordinates of the ultrasonic transceiver locations, including the catheter tip, from the measured distances. Feasibility of catheter tracking was initially studied using simulated data from a geometric model in which the actual coordinates of all transceivers were known. The method was then shown to be feasible in vivo by tracking a catheter-mounted piezoelectric transducer using seven reference crystals sewn to the epicardial surface of a sheep heart. Simulation results indicate that a catheter can be tracked with a root-mean-square (rms) error of 1.51 +/- 0.05 mm and an average-distance error of e = 1.06 +/- 0.27 mm using 12 reference points. In vivo results showed acceptable stress values (G < 0.05) for 95% of the data samples with an average-distance error of e = 0.52 +/- 0.66 mm. These simulation and experimental results show that sonomicrometry and MDS can be used to accurately localize the 3-D position and track the motion of a catheter tip within the heart.
本文介绍了一种使用超声心动图测量法和多维标度法（MDS）的数学方法来跟踪心脏导管三维（3-D）位置的技术。超声心动图测量法用于测量超声收发器之间的距离。然后使用MDS根据测量的距离计算超声收发器位置（包括导管尖端）的三维坐标。导管跟踪的可行性最初使用来自几何模型的模拟数据进行研究，该模型中所有收发器的实际坐标是已知的。然后通过使用七个缝合在羊心脏心外膜表面的参考晶体跟踪安装在导管上的压电换能器，证明该方法在体内是可行的。模拟结果表明，使用12个参考点时，导管跟踪的均方根（rms）误差为1.51 +/- 0.05 mm，平均距离误差为e = 1.06 +/- 0.27 mm。体内结果显示，95%的数据样本的应力值可接受（G < 0.05），平均距离误差为e = 0.52 +/- 0.66 mm。这些模拟和实验结果表明，超声心动图测量法和MDS可用于准确确定心脏内导管尖端的三维位置并跟踪其运动。
