Research of heart failure based on heart model and S1 complexity

Abstract

To study the internal and external characteristics of heart failure, a lumped-parameter cardiovascular simulation model is designed to analyze the internal characteristics, and a method is proposed that uses the complexity of the first heart sound (S1) amplitude sequence to analyze the external characteristics. State variable method is used to establish the mathematical expression of the cardiovascular model which includes three sub-models: systemic circulation sub-model, pulmonary circulation sub-model and heart sub-model. Based on this model the heart physiological feature is studied, especially under heart failure. Then, the complexity of S1 amplitude sequence is analyzed based on multiscale base-scale entropy algorithm. Simulation experiment shows that, one of the internal characteristics of heart failure is the reduction of myocardial elasticity coefficient, and one of the external characteristics is the reduction of the complexity of S1 amplitude sequence. Simulation result being in accord with clinical data indicates that the proposed approach has feasibility and practicability in heart failure diagnosis.