Patent ID: 7321847

Claim:
A digital signal averager for averaging a plurality of data scans, wherein each of said data scans comprises an analog signal waveform converted to digital signal data and said averaging comprises summing said digital signal data with digital signal data from previous scans said analog signal waveform being substantially repeatable with respect to the time of a trigger signal, said digital signal averager comprising: (a) means for generating a plurality of timing pulses; (b) an analog-to-digital converter for converting an analog signal to digital signal data in response to a first subset of said plurality of timing pulses; (c) means for summing said digital signal data produced during a first data scan with said digital signal data produced during at least one other scan in response to a second subset of said timing pulses, wherein, each datum of said first scan is summed with the datum of each of said at least one other scan that corresponds to substantially the same phase of said analog signal waveform, and wherein said summing causes a noise waveform to be added to said analog signal waveform, said noise waveform being substantially repeatable and in phase with said second subset of said timing pulses; and (d) means for generating a time delay between said trigger signal and the beginning of said second subset of said timing pulses, wherein said time delay is variable from one scan to another, so that said time delay generated for said at least one other data scan is substantially different from said time delay generated for said first data scan, whereby the relative phase between said noise waveform and said analog signal waveform during said at least one other scan is substantially different from said relative phase during said first scan; and (e) wherein said means for summing said digital signal data comprises means for compensating for said time delay differences, whereby each said datum of said first scan is summed with said datum of each of said at least one other scan that corresponds to substantially the same phase of said analog signal waveform as said datum of said first scan, whereby said substantially repeatable noise waveform is reduced in said summed digital signal data.