Hyatt Christopher J, Zemlin Christian W, Smith Rebecca M, Matiukas Arvydas, Pertsov Arkady M, Bernus Olivier
Department of Pharmacology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA.
Opt Express. 2008 Sep 1;16(18):13758-72. doi: 10.1364/oe.16.013758.
The development of voltage-sensitive dyes has revolutionized cardiac electrophysiology and made optical imaging of cardiac electrical activity possible. Photon diffusion models coupled to electrical excitation models have been successful in qualitatively predicting the shape of the optical action potential and its dependence on subsurface electrical wave orientation. However, the accuracy of the diffusion equation in the visible range, especially for thin tissue preparations, remains unclear. Here, we compare diffusion and Monte Carlo (MC) based models and we investigate the role of tissue thickness. All computational results are compared to experimental data obtained from intact guinea pig hearts. We show that the subsurface volume contributing to the epi-fluorescence signal extends deeper in the tissue when using MC models, resulting in longer optical upstroke durations which are in better agreement with experiments. The optical upstroke morphology, however, strongly correlates to the subsurface propagation direction independent of the model and is consistent with our experimental observations.
电压敏感染料的发展彻底改变了心脏电生理学，并使心脏电活动的光学成像成为可能。与电兴奋模型相结合的光子扩散模型已成功地定性预测了光学动作电位的形状及其对表面下电波方向的依赖性。然而，扩散方程在可见光范围内的准确性，特别是对于薄组织标本，仍不清楚。在这里，我们比较了基于扩散和蒙特卡罗（MC）的模型，并研究了组织厚度的作用。所有计算结果都与从完整豚鼠心脏获得的实验数据进行了比较。我们表明，使用MC模型时，对表面荧光信号有贡献的表面下体积在组织中延伸得更深，导致光学上升持续时间更长，这与实验结果更吻合。然而，光学上升形态与表面下传播方向密切相关，与模型无关，并且与我们的实验观察结果一致。
