Neural Signal Blocking Based on Spike Trapping Principle: Effect of Electrode and Pulse Parameters

Electrical stimulation of nerves to treat neurological disorders has been extensively studied. In this paper, a proactive blocking method, spike trapping, is introduced, which was previously referred to as the "antimissile strategy". Acute experiments on sciatic nerve-gastrocnemius muscle preparations of bullfrogs were performed to explore the parameters of this blocking method, including the size, spacing, and placement of the electrodes, as well as the widths of the cathodic triangular pulses used to trap the evoked neural signals. The block threshold voltage decreased with increasing electrode spacing and for larger diameter when the tripolar platinum wire electrodes were placed longitudinally on the same side of the sciatic nerve. However, there was no statistically significant difference between the minimum pulse widths which requires achieving nerve block with different electrode spacing or size. Placing bipolar electrodes of asymmetrical shape and size on the opposite sides across the nerve, the block threshold and the minimum pulse width both decreased first and then increased as a function of increasing anode width. Whether the electrodes is placed longitudinally along the nerve with tripolar configuration or transversely across the nerve with bipolar configuration, the nerve conduction can be instantaneously blocked without undesired excitation using the spike trapping strategy.