In this paper, we present a novel idea for analyzing blood circulation that is viewed as an electrical-driving, mechanical-pumping mechanism. Considering the electrocardiogram (ECG) and blood pressure wave (BPW) as the input and output signals of the system, we aim to quantify the spectral behavior of blood circulation from the viewpoint of resonance. First, the power spectrum of the ECG coincides well with that of the BPW for healthy subjects, but deviates significantly from the BPW’s for vascular patients. Second, bispectral analysis demonstrates a strong phase coupling between ECG and BPW in healthy subjects and a weaker coupling for subjects with vascular problems. Third, the transfer function for healthy subjects exhibits a flatter magnitude than that for patients. In addition, we propose a resonance circuit model of the spectral domain to represent blood circulation. The quality factor also exhibits better resonance characteristics for the healthy group than for the patient group.
