Multisite interstitial stimulation for cardiac micro-impedance measurements.
Multisite interstitial stimulation for cardiac micro-impedance measurements.
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用于心脏微阻抗测量的多部位间质刺激。
DOI：
10.1109/iembs.2006.260244
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Barr,RogerC
中科院分区：
文献类型：
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作者：
Pollard,AndrewE;Barr,RogerC
在理论上，使用近距离电极注入和移除的间质电流不会穿过膜，而细胞内和间质电位的平衡发生在远离电极的地方。因此，多点间质刺激应引起中心记录的间质电势差，这取决于细胞内和间质微阻抗，允许独立测量。我们测试了在包含Luo-Rudy Dynamic(LRD)膜方程的模型中，使用细间距和宽间距的多点刺激模拟来完成此类测量的可行性。使用二维模型，用为一组模拟规定的各向同性间质和细胞内微阻抗，以及用包括沿纤维和跨纤维的不等比(细胞内/间质)的各向异性微阻抗，为另一组模拟规定测试数据(Delaphi0)。然后，通过在考虑了广泛可能的微阻抗的被动双稳态模拟(Delaphi0)中对差值和间隙电势差进行统计比较来获得微阻抗测量。我们的发现表明，开发用于实施多部位刺激程序的微型制造设备将有助于作为心脏电生理研究的一个组成部分的常规测量
On theoretical grounds, interstitial current injected and removed using electrodes in close proximity does not cross the membrane, while equilibration of intracellular and interstitial potentials occurs distant from electrodes widely separated. Multisite interstitial stimulation should therefore give rise to interstitial potential differences recorded centrally that depend on intracellular and interstitial micro-impedances, allowing independent measurement. We tested the feasibility of completing such measurements using simulations of multisite stimulation with fine and wide spacing in models that included Luo-Rudy dynamic (LRd) membrane equations. Using two-dimensional models, test data (deltaphi0) were generated with isotropic interstitial and intracellular micro-impedances prescribed for one set of simulations, and with anisotropic micro-impedances including unequal ratios (intracellular/interstitial) along and across fibers prescribed for another set of simulations. Micro-impedance measurements were then obtained by making statistical comparisons between deltaphi0values and interstitial potential differences from passive bidomain simulations (Deltaphi0) in which a wide range of possible micro-impedances were considered. Our findings suggest development of microfabricated devices to implement the multisite stimulation procedure would facilitate routine measurement as a component of cardiac electrophysiologic study