Stasiunas Antanas, Verikas Antanas, Miliauskas Rimvydas, Stasiuniene Natalija, Bacauskiene Marija
Department of Applied Electronics, Kaunas University of Technology, LT-51368 Kaunas, Lithuania.
Med Eng Phys. 2008 Mar;30(2):171-81. doi: 10.1016/j.medengphy.2007.03.002. Epub 2007 Apr 19.
We designed a non-linear functional model of the outer hair cell (OHC) functioning in the filtering system of the cochlea and then isolated from it two second-order structures, one employing the mechanism of the somatic motility and the other the hair bundle motion of the OHC. The investigation of these circuits showed that the main mechanism increasing the sensitivity and frequency selectivity of the filtering system is the somatic motility. The mechanism of the active hair bundle motion appeared less suitable for realization of the band-pass filtering structures due to the dependence of the sensitivity, natural frequency and selectivity on the signal intensity. We combined three second-order filtering structures employing the mechanism of the somatic motility and the lateral inhibition to form a parallel-type filtering channel of the sixth order with the frequency characteristics of the Butterworth-type and Gaussian-type. The investigation of these channels showed that the Gaussian-type channel has the advantage over the Butterworth-type channel. It is more suitable for realization of a filter bank with common lateral circuits and has less distorted frequency characteristic in the nonlinear mode.
我们设计了一种在外毛细胞（OHC）在耳蜗滤波系统中发挥作用的非线性功能模型，然后从中分离出两个二阶结构，一个采用体细胞运动机制，另一个采用OHC的毛束运动机制。对这些电路的研究表明，提高滤波系统灵敏度和频率选择性的主要机制是体细胞运动。由于灵敏度、固有频率和选择性对信号强度的依赖性，主动毛束运动机制似乎不太适合实现带通滤波结构。我们将采用体细胞运动机制和侧向抑制的三个二阶滤波结构组合起来，形成一个具有巴特沃斯型和高斯型频率特性的六阶并联型滤波通道。对这些通道的研究表明，高斯型通道优于巴特沃斯型通道。它更适合于实现具有公共侧向电路的滤波器组，并且在非线性模式下频率特性失真较小。
