Computer-assisted evaluation of the smooth-muscle electromyogram of the corpora cavernosa by fast Fourier transformation.

Abstract

The aim of our study was to investigate analogous and digital recording of corpus cavernosum EMGs (CC-EMGs) in normal men according to criteria that were recently agreed upon in an international consensus workshop. CC-EMGs were analogously and digitally registered from 37 normal subjects. Power spectra in the frequency domain were determined via fast Fourier transformation (FFT). Thirty-one of men showed identical or at least very similar electrical activity patterns in the analogous and digital registration. Needle penetration artifacts (investigated in 18 subjects) were found in 17/18 CC-EMGs during the first 20 min. Power spectra show a maximum of power at a frequency of 0.3 Hz with more than 90% of the power located between 0 and 5 Hz. Registration of CC-EMGs in normal men resulted in interindividually reproducible recordings. Age hardly affected CC-EMGs. Computer-assisted evaluation by FFT after elimination of artifacts was feasible. Thus, interpretation of the CC-EMG signals by a computer-aided expert system seems to be promising for clinical routine, in particular with respect to an increase in objectivity and a decrease in time needed for interpretation.