System analysis of blood circulation based on coherence power transfer: From electrical driving to mechanical vibration

Abstract

We analyze blood circulation based on the basis of the system viewpoint and coherence power transfer from electrical energy (ECG) to mechanical power (blood pressure wave). The coherent oscillation between the driving signal and the vibration of the cardiovascular system is investigated by coherence function and the perturbations of the system are found. In addition, we develop a mathematical equation to describe the phenomenon. The average peak coherence value S for the first live harmonics is utilized as an index to quantify the power coherence effect. The evaluated p-value (< 0.01) reveals that the distinction of power coherence between the healthy subjects and cardiovascular patients is significant. Consequently, we conclude that if the S approaches a value close to one, the output is almost completely attributed to input and fewer perturbation signals influence the system: therefore, the cardiovascular system stays in a better condition. Conversely, if S approaches a value less than one, larger perturbations will worsen the cardiovascular system condition.