整合電極-電解液層和電流操控機制於方向性電極並將其應用於腦深層電刺激

Abstract

本論文之主要目的在利用一個有關被刺激組織的體積量化方法以改良神經刺激於腦深層電刺激之中，腦部區域像是STN，。並使用電流操控技術控制在組織中引起刺激的範圍。於此篇論文中，應用了新型單顆、雙顆、三顆電極的電流操控技術在腦深層電刺激上，而電流操控技術在人工電子耳已使用多時。以有限元素方法建立模型以模擬人類腦中神經組織，並給予其模型刺激，可利用數學方程式計算在組織中引起刺激的範圍，以便於計算在模型當中模擬腦深層電刺激所產生的有效刺激範圍。此外，加入整合法拉第效應的電極-組織層，一併計算於腦深層電刺激模型當中。於此，有效刺激範圍可計算出有無法拉第效應的電極-組織層結果分別出此層的功用。更甚於此，將原本環狀電極分成四片電極，帶有方向性的電極可引起有方向性特地的刺激範圍，藉由數學公式的推導計算，可控制有效刺激範圍於特定方向中。

The objective of this paper is to develop a quantitative understanding about the shape and the volume of tissue activated (VTA) and stimulation site by deep brain stimulation (DBS). In the deep brain area, like subthalamic nucleus (STN), the DBS stimulation using current steering scheme to control VTA. In this paper, novel monopolar, bipolar, and tripolar current steering configurations are applied to deep brain stimulation. Current steering configuration has been used in cochlear implant and DBS systems. Finite element models (FEM) of deep brain stimulation are used to study the VTA for current steering configurations. Additionally, faradaic reaction is incorporated in the electrode-tissue interface in the DBS model. The VTA is calculated from a DBS model with or without faradaic reaction incorporated in the electrode-tissue interface. Furthermore, The DBS used directional electrodes to control the directional property of VTA. The conventional each ring electrode is replaced by directional electrodes, each directional electrode has four parts of electrode. The results show that the VTA exhibits directional property. The DBS given stimulate parameter; by mathematic formula can compute VTA in brain model. It can generate a valid stimulated region on compute the simulating DBS.