并引入膜电位的全局偏导数判别湍流的抑制效果。计算机仿真结果表明:恒定电场法抑制湍流的时间小于50 ms
周期场法需历时200 ms
但两种方法电场的实际作用时间无显著差异; 尽管周期场法产生的总热能是恒定电场法的2.3倍
但周期场法一个周期产生的热能仅为恒定电场法的一半。因此
恒定电场法具有消除湍流快、总热能低的特点
但周期场法由于电场断续式地施加
更有利于减小热的持续积累对心肌的损伤。
Abstract
Aiming at the myocardial cell membrane oscillation induced by phase-2 early afterdepolarization(EAD)due to voltage oscillation
two turbulence control methods based on constant and periodic electrical fields were presented and compared. A 2-dimensional tissue including 400×400 cells was developed based on the LR91 model. By increasing the time constant of K
+
current gating variable and the maximum conductance of Ca
2+
current by 4 and 2 times respectively
an EAD region with 20×20 cells was created in the center of the tissue model. The cross field method was used to induce spiral wave
which was degraded to turbulence due to EAD. The defibrillation model was created
by introducing an electric field term in the reaction-diffusion equation. The inhibition efficiency was evaluated by using an introduced global partial derivative. Computer simulation results showed that the constant and periodic electric fields required 50 ms and 200 ms to eliminate the turbulence
respectively
but their actual delivery time has no significant difference. The total thermal energy produced by the periodic field was 2.3 times that by the constant field
while the heat produced within one period by the periodic field was half of that by constant field method. Therefore
the constant electric field method is characterized by faster turbulence elimination and less thermal energy consumption
while the periodic method can bring less damage to cardiac muscle because of its intermittent delivery nature.
关键词
Keywords
references
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