Koole P, Holsheimer J, Struijk J J, Verloop A J
Department of Electrical Engineering, University of Twente, Enschede, The Netherlands.
IEEE Trans Rehabil Eng. 1997 Mar;5(1):40-50. doi: 10.1109/86.559348.
The recruitment characteristics of fascicle-selective nerve stimulation by a multigroove electrode have been investigated both theoretically and in acute experiments. A three-dimensional (3-D) volume conductor model of fascicles in a multigroove device and a model of myelinated nerve fiber stimulation were used to calculate threshold stimuli of nerve fibers in these fascicles. After their exposition, fascicles from rat sciatic nerve were positioned in different grooves of appropriate sizes and stimulated separately. The device appeared to be suitable for fascicle-selective stimulation, because both computer simulations and acute animal experiments showed that crosstalk between neighboring fascicles is not a problem, even when monopolar stimulation was used. The threshold stimulus was lower for a small fascicle than for a large one. When the amount of (conducting) medium between contact and perineurium or its conductivity was reduced, threshold stimuli were lower. Moreover, simulations predict that the slopes of recruitment curves are smaller and inverse recruitment order is less pronounced. Simulations also showed that a small contact is preferable to a large on, because a small contact gives a slightly smaller slope of the recruitment curve. Both experimentally and theoretically a significantly smaller slope of recruitment curves was obtained by stimulation with a cathode and an anode at opposite sides of the fascicle, driven by two current sources giving simultaneous pulses with different, but linearly dependent amplitudes.
通过多槽电极进行束状选择性神经刺激的募集特性已在理论和急性实验中进行了研究。使用多槽装置中束状结构的三维（3-D）容积导体模型和有髓神经纤维刺激模型来计算这些束状结构中神经纤维的阈刺激。在暴露后，将大鼠坐骨神经的束状结构放置在适当尺寸的不同槽中并分别进行刺激。该装置似乎适用于束状选择性刺激，因为计算机模拟和急性动物实验均表明，即使使用单极刺激，相邻束状结构之间的串扰也不是问题。小束状结构的阈刺激低于大束状结构。当接触点与神经束膜之间的（传导）介质量或其电导率降低时，阈刺激会降低。此外，模拟预测募集曲线的斜率较小且反向募集顺序不太明显。模拟还表明，小接触点比大接触点更可取，因为小接触点给出的募集曲线斜率略小。通过在束状结构的相对两侧用阴极和阳极进行刺激，由两个电流源驱动，同时给出不同但线性相关幅度的脉冲，在实验和理论上均获得了明显更小的募集曲线斜率。
