Jolly C N, Spelman F A, Clopton B M
Center for Bioengineering, University of Washington, Seattle 89195-7962, USA.
IEEE Trans Biomed Eng. 1996 Aug;43(8):857-65. doi: 10.1109/10.508549.
Cochlear implants are electrically driven in monopolar, bipolar, or common ground mode. Ideally, a quadrupolar mode is created with three colinear electrodes, where the outer poles are half the inverse polarity value of the center electrode. The resulting field is highly focused. Models of point sources show that the quadrupolar paradigm offers a greater choice of parameters to shape the field. Simulation with a lumped-parameter model of the cochlea confirms the focusing action of the quadrupole in the layers of the inner ear. Field measurements in saline solution and in the scala tympani of guinea pigs show that focusing occurs with the quadrupolar mode. It is conceivable that quadrupolar stimulation will affect the pitch place coding, reduce channel interaction and limit facial or tactile stimulation induced by current spread.
人工耳蜗以单极、双极或共地模式进行电驱动。理想情况下，通过三个共线电极创建四极模式，其中外极的反极性值是中心电极的一半。由此产生的场高度聚焦。点源模型表明，四极模式提供了更多塑造场的参数选择。用耳蜗的集总参数模型进行模拟，证实了四极在内耳各层中的聚焦作用。在盐溶液和豚鼠鼓阶中的场测量表明，四极模式会产生聚焦。可以想象，四极刺激将影响音调位置编码，减少通道相互作用，并限制电流扩散引起的面部或触觉刺激。
