Dynamic modeling and simulation of the human cardiovascular system with PDA

2022 ◽  
Vol 71 ◽  
pp. 103151
Author(s):  
Estela Ortiz-Rangel ◽  
Gerardo Vicente Guerrero-Ramírez ◽  
Carlos Daniel García-Beltrán ◽  
Marcela Guerrero-Lara ◽  
Manuel Adam-Medina ◽  
...  
2000 ◽  
Vol 39 (02) ◽  
pp. 118-121 ◽  
Author(s):  
S. Akselrod ◽  
S. Eyal

Abstract:A simple nonlinear beat-to-beat model of the human cardiovascular system has been studied. The model, introduced by DeBoer et al. was a simplified linearized version. We present a modified model which allows to investigate the nonlinear dynamics of the cardiovascular system. We found that an increase in the -sympathetic gain, via a Hopf bifurcation, leads to sustained oscillations both in heart rate and blood pressure variables at about 0.1 Hz (Mayer waves). Similar oscillations were observed when increasing the -sympathetic gain or decreasing the vagal gain. Further changes of the gains, even beyond reasonable physiological values, did not reveal another bifurcation. The dynamics observed were thus either fixed point or limit cycle. Introducing respiration into the model showed entrainment between the respiration frequency and the Mayer waves.


2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Guoping Wang ◽  
Bao Rong ◽  
Ling Tao ◽  
Xiaoting Rui

Efficient, precise dynamic modeling and control of complex underwater towed systems has become a research focus in the field of multibody dynamics. In this paper, based on finite segment model of cable, by defining the new state vectors and deducing the new transfer equations of underwater towed systems, a new highly efficient method for dynamic modeling and simulation of underwater towed systems is presented and the pay-out/reel-in process of towed cable is studied. The computational efficiency and numerical stability of the proposed method are discussed. When using the method to study the dynamics of underwater towed systems, it avoids the global dynamic equations of system, and simplifies solving procedure. Irrespective of the degree of freedom of underwater towed system, the matrices involved in the proposed method are always very small, which greatly improve the computational efficiency and avoids the computing difficulties caused by too high matrix orders for complex underwater towed systems. Formulations of the method as well as numerical simulations are given to validate the proposed method.


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