Effect of stimulus pulsewidth on spatial selectivity of neural stimulation
The objective of this study was to determine the effect of stimulus pulsewidth (PW) on selective activation of peripheral nerve fibers. Computer simulations using a cable model of a mammalian myelinated nerve fiber indicated that shorter PWs increased the difference between the threshold currents of fibers lying at different distances from an electrode. Experiments conducted in a cat model revealed that shorter PWs generated larger torques before spillover, and created a larger range of currents over which the torque was a monotonically increasing function of the stimulus current amplitude. Thus, shorter PWs allowed more spatially selective stimulation of nerve fibers.