Fig. 2

Left: In-vivo experimental setup. A bipolar electrode was placed on the proximal portion of the sciatic nerve to elicit twitches from the gastrocnemius muscle. A second bipolar electrode was placed distally on the nerve. The block electrode was placed between the two stimulating electrodes on the sciatic nerve. The gastrocnemius tendon was attached to a force transducer to record muscle twitches. The blocking waveforms (12 samples per cycle) were delivered from a data acquisition device via an isolated amplifier. The voltage across a 100 Ω series resistor was recorded using an oscilloscope in order to measure peak current at BT. Right: The voltage across a series resistor (100 Ω) in the return path was measured on a high-impedance oscilloscope. Examples are at BT for 20 kHz