Many trials to get informations from arterial waveforms have been done. But it was not so simple as expected because of normally fluctuating characteristics of arterial waveform due to respiration, extracardiac neuro-humoral control, etc. By using power spctral analysis we can figure out powers of these extrinsic contribting factors as well as contours of individual pulse wave by harmonic analysis. The purpose of this study is to compare the results of power spectral analysis and some basic parameters of arterial waveform before and after anesthesia to establish the basic changes during halothane anesthesia. The analog informations, obtained from patients undergoing operation with radial artery cannulated for continuous monitoring, was obtained from analog output of the Cardiocap monitor. It was transformed to digital information by A/D converter and saved to IBM compatible computer with mathcoprocessor. The data was processed offline by the signal analysis software DADiSP version 1.05 with the same computer. Results of mean arterial pressure, heart rate, dp/dt, low frequency peak, high frequency peak and harmonic pulse contour analysis were compared before and after anesthesia. We could conclude that halothane anesthesia diminishes all powers of harmonic components of arterial wave and powers of extrinsic components that affect low frequency area.
Anesthesia* ; Arterial Pressure ; Chromonar ; Halothane* ; Heart Rate ; Humans ; Radial Artery ; Respiration