A Novel Waveform for No-Onset Nerve Block Combining Direct Current and Kilohertz Frequency Alternating Current.

Kilohertz frequency alternating current (KHFAC) has been shown to produce a fast acting, reversible nerve block. The principal drawback to this technique is a short, but intense burst of firing at the initiation of the KHFAC which is referred to as the "onset response". The "onset response" can be eliminated by the use of a second electrode which delivers direct current (DC) briefly during the onset duration. However, the DC cannot be delivered for a sufficiently long time to suppress the onset without causing damage to the nerve. High surface area electrodes have been developed which can be used to deliver DC for long enough to eliminate the onset without causing damage. Furthermore, instead of using multiple electrodes to create a no onset block, the DC and KHFAC are combined in novel waveform which can be output on a single monopolar electrode. This novel waveform has been demonstrated to prevent onset in both simulation and in an in vivo rat sciatic nerve model.