A Microcomputer System Computing Statistical Quantities from Intervals between Nerve Impulses with Different Heights

To compute the statistical characteristics of impulses recorded externally in nerve fibers, a microcomputer system was made up by utilizing two computer kits (MOTOROLA MEK-6800 DII). Two computers were connected with the stimulator, A/D converter, pulse counter, peak discriminator, and some additional electronic circuits. The combined system could measure the interval of impulses with different heights. The one microcomputer controlled the input gate of another microcomputer, and could give rise to the adjusted stimulus waveform, i.e. the train of sinusoidal waveform with several time intervals. Another one was the data processing one and had 8.5 Kbyte RAMs. This computed statistical properties as post stimulus time (PST) histogram, interval histogram, and cross-correlation histogram from the measured intervals. The microcomputer system was used in analyzing the impulses recorded in the mechanoreceptor nerve fibers on crayfish first antenna.