Ren C, Tarjan P P, Popović D B
Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33124, USA.
IEEE Trans Biomed Eng. 1995 Sep;42(9):918-25. doi: 10.1109/10.412658.
A novel coil design for inductive electromagnetic stimulation of neural cells has been simulated and experimentally tested. This coil improves the focal effect of a magnetic stimulator, and it reduces its inductance, hence the efficiency of the system is improved. The basic structure of the device is derived from the popular "Slinky" toy. The actual device is formed by winding different numbers of loops forming a helical coil on a half torus. The loops are bunched at the axis of the torus. The coil, due to its geometry, generates a unique distribution of eddy currents in nearby tissues which is favorable compared to a solenoid type stimulator. This renders the Slinky coil more selective than conventional coils used for magnetic stimulation. The distribution of eddy currents was analyzed using Matlab, following Faraday's Law of Induction. Improved focality permits the current through the coil to be reduced for the same effect. In addition, the reduced inductance of the Slinky coil decreases the power requirement; thus, the improved efficiency of the system may allow the generation of bursts of pulses, and expand the utilization of the system to possible functional activation of certain neuro-muscular structures when peripheral nerves are stimulated.
一种用于感应式电磁刺激神经细胞的新型线圈设计已通过模拟和实验测试。该线圈提高了磁刺激器的聚焦效果，并降低了其电感，从而提高了系统效率。该装置的基本结构源自流行的“弹簧圈”玩具。实际装置是通过在半圆环上缠绕不同数量的线圈形成螺旋线圈而成。这些线圈在圆环的轴线上聚集。由于其几何形状，该线圈在附近组织中产生独特的涡流分布，与螺线管式刺激器相比更具优势。这使得弹簧圈线圈比用于磁刺激的传统线圈更具选择性。根据法拉第电磁感应定律，使用Matlab分析了涡流分布。改进的聚焦效果使得在产生相同效果时可以减少通过线圈的电流。此外，弹簧圈线圈电感的降低减少了功率需求；因此，系统效率的提高可能允许产生脉冲串，并在刺激外周神经时将系统的应用扩展到对某些神经肌肉结构的可能功能激活。
