title: Automated measurement and frequency analysis of the pneumocardiogram.
abstract: The flow pneumocardiogram (PnCG), ie, measurement of cardiogenic gas movement in and out of the lung during apnea, was transduced by an in-line, high-gain pneumotachograph. A portion of the differentiated PnCG, the dPn/dt IJ wave, has been shown previously to correlate closely with left ventricular function. A simple analog device was designed and tested to measure the dPn/dt IJ amplitude on a practical beat-to-beat basis. Frequency-power spectral analysis showed the PnCG to be a low frequency phenomenon with the systolic component in the 9-to-10-Hz range. Appropriate band-pass filtering of the PnCG and its applicability as an intraoperative monitoring device are presented.
mesh_terms: D000703:Analog-Digital Conversion; D000769:Anesthesia, Inhalation / Q000379:methods*; D000818:Animals; D003626:Data Display; D004285:Dogs; D006334:Heart Function Tests / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008722:Methods; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D009200:Myocardial Contraction; D009862:Online Systems; D012119:Respiration