Department of Electrical and Computer Engineering, Tufts University, Medford, MA 02155, USA.
J Neural Eng. 2011 Jun;8(3):036017. doi: 10.1088/1741-2560/8/3/036017. Epub 2011 May 4.
Standard bioelectric field models assume that the tissue is purely resistive and frequency independent, and that capacitance, induction, and propagation effects can be neglected. However, real tissue properties are frequency dependent, and tissue capacitance can be important for problems involving short stimulation pulses. A straightforward interpolation scheme is introduced here that can account for frequency-dependent effects, while reducing runtime over a direct computation by several orders of magnitude. The exact Helmholtz solution is compared to several approximate field solutions and is used to study neural stimulation. Results show that frequency-independent tissue capacitance always acts to attenuate the stimulation pulse, thereby increasing firing thresholds, while the dispersion effects introduced by frequency-dependent capacitance may decrease firing thresholds.
标准的生物电场模型假设组织是纯电阻且频率无关的，并且可以忽略电容、感应和传播效应。然而，实际组织的性质是频率相关的，对于涉及短刺激脉冲的问题，组织电容可能很重要。这里引入了一种直接的插值方案，可以考虑频率相关的影响，同时将运行时间减少几个数量级。将精确的亥姆霍兹解与几个近似场解进行了比较，并用于研究神经刺激。结果表明，频率无关的组织电容总是会衰减刺激脉冲，从而增加激发阈值，而频率相关的电容引起的色散效应可能会降低激发阈值。
