Center for Devices and Radiological Health, FDA, Silver Spring, MD, USA.
Phys Med Biol. 2010 Dec 7;55(23):7253-61. doi: 10.1088/0031-9155/55/23/005. Epub 2010 Nov 16.
The objective of this study was to develop a numerical solver to calculate the magneto-hydrodynamic (MHD) signal produced by a moving conductive liquid, i.e. blood flow in the great vessels of the heart, in a static magnetic field. We believe that this MHD signal is able to non-invasively characterize cardiac blood flow in order to supplement the present non-invasive techniques for the assessment of heart failure conditions. The MHD signal can be recorded on the electrocardiogram (ECG) while the subject is exposed to a strong static magnetic field. The MHD signal can only be measured indirectly as a combination of the heart's electrical signal and the MHD signal. The MHD signal itself is caused by induced electrical currents in the blood due to the moving of the blood in the magnetic field. To characterize and eventually optimize MHD measurements, we developed a MHD solver based on a finite element code. This code was validated against literature, experimental and analytical data. The validation of the MHD solver shows good agreement with all three reference values. Future studies will include the calculation of the MHD signals for anatomical models. We will vary the orientation of the static magnetic field to determine an optimized location for the measurement of the MHD blood flow signal.
本研究的目的是开发一种数值求解器，以计算在静态磁场中运动的导电液体（即心脏大血管中的血流）产生的磁流体动力学（MHD）信号。我们相信，这种 MHD 信号能够无创地对心脏血流进行特征描述，以补充目前用于评估心力衰竭状况的无创技术。当受检者暴露于强静磁场时，可以在心电图（ECG）上记录 MHD 信号。MHD 信号只能作为心脏电信号和 MHD 信号的组合间接测量。MHD 信号本身是由于血液在磁场中的移动而在血液中感应出的电流引起的。为了对 MHD 测量进行特征描述并最终进行优化，我们基于有限元代码开发了一种 MHD 求解器。该代码经过文献、实验和分析数据的验证。MHD 求解器的验证结果与所有三个参考值吻合良好。未来的研究将包括对解剖模型的 MHD 信号进行计算。我们将改变静磁场的方向，以确定测量 MHD 血流信号的最佳位置。
