Spectral analysis of digital pulse plethysmograms during autonomic nervous system changes

Spectral analysis of physiologic waveforms provides a window into the autonomic nervous system. Although electrocardiograms (EKG) and arterial blood pressure waveforms (ABP) have been analyzed extensively in this manner, the authors' objective was to determine if similar information could be extracted from digital pulse plethysmograms (DPP). DPP spectral analysis during application of known autonomic stimuli (hypoxemia, phenyleprine, general anesthesia) resulted in the anticipated changes in autonomic spectra. DPP may provide autonomic information regarding the peripheral circulation which is not available in EKG, and less invasive than ABP.