The effect of the delay time betvveen pulses on conduction velocity distribution histograms in double pulse method

The first and the second compound action potentials (CAP1 ,CAP2) arisen from the double stimulation of the nerve on the same polnt were recorded using the suction techniçue. The changes in CAP2 signals were observed as the delay time between two stimuli was reduced. İn order to obtaln the CAP fiber diameter distribution histograms, a model developed in our previous work was applied to CAP1 and CAP2 recordings. The changes in CAP2 histograms were compared to CAP1 histograms’ as the delay times got shorter. As inter-stimu/i delay time gets shorter, significant difference betvveen CAP1 and CAP2 histograms appears at 3.4th ms after CAP1. Although double pulse stimulation techniçue is essential for determining the refractor period duration, it is unsatisfactory for deducing vvhole nerve activity, since the late phase of CAP1 interferes into early phase of CAP2 as the delay time gets shorter.