We conclude that both sinusoidal and square waveforms at frequencies of 20 kHz or higher would be optimal.

For 10 and 20 kHz, carbon black coating significantly reduced the charge required for nerve block. Electrodes with carbon black coatings gave significantly lower block thresholds and reduced onset responses across all blocking frequencies. Electrode comparisons were performed only in-vivo. Onset parameters were affected by blocking frequency but not by waveform shape. When converted to charge per cycle, square waveforms required the maximum charge per phase, and triangular waveforms the least. Block thresholds were significantly different between waveforms lowest for the square waveform and highest for triangular waveform. Resultsįor the majority of parameters, in-vivo testing and simulations showed similar results: Block thresholds increased linearly with frequency for all three waveforms. In-vivo results were compared with computational modeling conducted using the NEURON simulation environment using a nerve membrane model modified for stimulation in the kilohertz frequency range. We determined the minimum amplitude that could completely block motor nerve conduction (block threshold), and measured properties of the onset response, which is a transient period of nerve activation at the start of block. Bare platinum electrodes were compared with carbon black coated electrodes. Three blocking waveforms were delivered (sinusoidal, square and triangular) at 6 frequencies (10–60 kHz). Bipolar electrodes were used to electrically block motor nerve impulses in the sciatic nerve, as measured using force output from the gastrocnemius muscle. Materials and methodsĪcute in-vivo experiments were performed on 12 rats.

We determined the effects of waveform shape using two types of electrodes. It is not clearly known how the waveform shape affects block outcomes, and if waveform effects are frequency dependent. KiloHertz frequency alternating current waveforms produce conduction block in peripheral nerves.

Bipolar square wave