Using a Human Cardiopulmonary Model to Study and Predict Normal and Diseased Ventricular Mechanics, Septal Interaction, and Atrio-Ventricular Blood Flow Patterns

Abstract

We upgraded our human cardiopulmonary (CP) model with additional data that enables it to more accurately simulate normal physiology. We then tested its ability to explain human disease by changing two parameter values that decrease ventricular compliance, and found that it could predict many of the hemodynamic, gas exchange, and autonomic abnormalities found in patients with left ventricular diastolic dysfunction (LVDD). The newly incorporated information includes high-fidelity pressure tracings simultaneously recorded from the RV and LV of a normal human in a cardiac catheterization laboratory, Doppler echocardiographic inlet flow velocity patterns, measures of right and left ventricular impedance, and atrial volumes. The revised cardiovascular section details the hemodynamics of a normal subject to the extent that it can now explain the effects of septal compliance on ventricular interaction, the differences in left and right ventricular pressure development, and venous blood gas mixing in the right atrium. The model can isolate the highly interrelated features of normal and abnormal physiology, and simultaneously demonstrate their interaction in a manner that would be very difficult or impossible using an intact organism. It may therefore help physicians and scientists understand, diagnose, and improve their treatment of complicated cardiovascular and pulmonary diseases. It could also simulate the hemodynamic and respiratory effects of ventricular and pulmonary assist devices, and thus help with their development.

Automation of a portable extracorporeal circulatory support system with adaptive fuzzy controllers

“…Brawany [61] described a cardiovascular model with malfunctions and included the effect of different drugs. Luo et al [46] created a cardiopulmonary to study and predict normal and diseased ventricular mechanics.…”

“…The heart was com- posed of a four compartment element with the corresponding valves represented as diodes [43][44][45][46][47][48][49][50][51]. The relation of pressure (P), volume (V) and flow (Q) was used in relation to the neighbor component considering resistance (R), compliance (C) and inductance (L) elements.…”

Modeling the Cardiovascular-Respiratory Control System: Data, Model Analysis, and Parameter Estimation

“…Examples of models at various levels of detail include Heldt et al (2002) and Magosso and Ursino (2004). The combined cardio-respiratory model developed in a series of papers in Lu et al (2001Lu et al ( , 2004 and Luo et al (2007) reflect the interaction of such design factors. This model includes detailed cardiovascular and respiratory components.…”

Unique parameter identification for cardiac diagnosis in critical care using minimal data sets

“…Lumped parameter models (LPM) are a common approach to minimizing complexity in the cardiovascular system [12][13][14][15][16] but there are still many parameters involved. Thus typically, only small subsets of the parameter set can be identified (e.g.…”

“…A common method of modelling the CVS is by a series of elastic chambers connected by resistors with a time varying elastance. This approach has been well developed and validated in the literature [12][13][14][15][16] so it serves as a good starting point to test the methods and concepts in this paper. The specific baseline model structure considered is a six chamber cardiovascular model including ventricular interaction and inertial effects that has been previously developed [16] and validated in clinical animal trials [21][22][23][24].…”