Barak C, Leviatan Y, Inbar G F, Hoekstein K N
Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa.
Med Biol Eng Comput. 1992 Sep;30(5):473-80. doi: 10.1007/BF02457824.
Using the electrical impedance measurement technique to investigate stroke volume estimation, three models of the ventricle were simulated. A four-electrode impedance catheter was used; two electrodes to set up an electric field in the model and the other two to measure the potential difference. A new approach, itself an application of the quasi-static case of a method used to solve electromagnetic field problems, was used to solve the electric field in the model. The behaviour of the estimation is examined with respect to the electrode configuration on the catheter and to catheter location with respect to the ventricle walls. Cardiac stroke volume estimation was found to be robust to catheter location generating a 10 per cent error for an offset of 40 per cent of the catheter from the chamber axis and rotation of 20 degrees with respect to the axis. The electrode configuration has a dominant effect on the sensitivity and accuracy of the estimation. Certain configurations gave high accuracy, whereas in others high sensitivity was found with lower accuracy. This led to the conclusion that the electrode configuration should be carefully chosen according to the desired criteria.
使用电阻抗测量技术来研究每搏输出量估计，模拟了三种心室模型。使用了四电极阻抗导管；两个电极在模型中建立电场，另外两个电极测量电位差。采用了一种新方法，该方法本身是用于解决电磁场问题的一种方法的准静态情况的应用，来求解模型中的电场。针对导管上的电极配置以及导管相对于心室壁的位置，研究了估计行为。发现心脏每搏输出量估计对导管位置具有鲁棒性，当导管偏离腔室轴线40%且相对于轴线旋转20度时，产生10%的误差。电极配置对估计的灵敏度和准确性有主要影响。某些配置具有高精度，而在其他配置中则发现高灵敏度但准确性较低。由此得出结论，应根据期望的标准仔细选择电极配置。
