动态躯干—左心室模型的初步研究

A Preliminary Study of the Dynamic Torso-Left Ventricular Model

为研究心室变化对心脏磁场的影响,本文利用健康人彩色多普勒成像提取一个心动周期的左心室图像数据,建立了一个动态的磁场边界元模型。文中基于该模型研究了电流偶极子在左心室舒张期220 ms和320 ms时刻所产生的心脏磁场数据,结果显示当偶极子位于左心室腔内时,220 ms时刻的磁场强度大于320 ms时刻的磁场强度;当偶极子位于左心室腔外(心肌中)时,磁场强度相对前者的变化小,且320ms时刻的磁场强度略小于220ms时刻的磁场强度。此外文中仿真了健康人的整个心动周期的心脏磁场,并与实测的心脏磁场数据进行了对比,仿真结果显示仿真的心脏磁场的强度整体上小于实测磁场。这说明了利用彩色多普勒成像数据分别对左心室舒张初期和舒张末期的心脏磁场进行建模仿真能获得更多的特征信息。

In order to study the influence of ventricular changes on the heart magnetic field, this paper established a dynamic magnetic field boundary element model using a healthy human color Doppler imaging to extract the left ventricular image data of a cardiac cycle. In this paper, we studied the cardiac magnetic field data generated by the current dipole at left 220 ms and 320 ms based this model. The results showed that the dipole in the left ventricle the intensity of the magnetic field at 220 ms is greater than intensity of the magnetic field at 320 ms;when the dipole out the left ventricle(in the myocardium) the intensity of the magnetic field is smaller than the former, and the intensity of the magnetic field at 320 ms is slightly smaller than intensity of the magnetic field at 220 ms. In addition,we simulated a whole heart cycle of the healthy people’s heart magnetic field and compared with the SQUID magnetic field data. The simulation results show that the intensity of the simulated cardiac magnetic field is less than the SQUID magnetic field. It indicates that more characteristic information can be obtained by modeling and simulating the cardiac magnetic field at the left ventricular initial-diastolic and end-diastolic respectively by using color Doppler four-dimensional imaging data.