Magnitude Variation of Arterial Blood Pressure Measured Using Holo–Hilbert Spectral Analysis

Arterial blood pressure (ABP) is one of the most crucial cardiovascular indicators in clinical practice. Hilbert–Huang transform (HHT) has been performed on ABP signals and resulted in ABP variability. The instantaneous P-wave interval variation had been further examined with baroreflex sensitivity. However, the instantaneous magnitude variation of ABP signal is still unclear with the pulse pressure (PP) variability. In 2016, Holo–Hilbert spectral analysis (HHSA) extended the HHT method for identifying the amplitude-modulated (AM) characteristics of signals. This method was applied to investigate the magnitude variation of ABP signal during different respiratory manipulations in this study. The results indicated that the AM parts were moderately correlated with PP series and corresponding respiratory patterns. The [Formula: see text]-values on PP series are [Formula: see text], and [Formula: see text] for spontaneous breathing, six-cycle breathing, and hyperventilation, respectively. The values on respiratory patterns are [Formula: see text], and [Formula: see text] for spontaneous breathing, six-cycle breathing, and hyperventilation, respectively. This study concludes that ABP signal with HHSA presents the corresponding PP series, the respiratory-related activities, and the respiratory effect on PP variability. This is the first demonstration of the magnitude variation of ABP signal and further research in this area is warranted.