A comparison of overall mathematical models of the cardiovascular system for simulating response to orthostatic...

Area of Science:

• Physiology
• Biomedical Engineering
• Mathematical Modeling

Background:

• Numerous cardiovascular system (CVS) models exist, but few comprehensively model the heart, vasculature, and control elements.
• Existing models vary in complexity and are often stimulus-specific, with limited reported accuracy across diverse stimuli.
• The ability of mathematical models to accurately simulate responses to a wide range of orthostatic stresses has not been well-established.

Purpose of the Study:

• To examine and compare the performance of three distinct mathematical models of the CVS.
• To assess the models' accuracy in simulating short-term orthostatic responses to lower body negative pressure (LBNP), head-up tilt, and blood loss.
• To validate model responses against available experimental data for orthostatic stress simulations.

Main Methods:

• Evaluation of three mathematical models: Croston and Fitzjerrell's (C), Jaron et al.'s (J), and Pullen's (P).
• Simulation of cardiovascular responses to orthostatic stresses including lower body negative pressure (LBNP), head-up tilt, and simulated blood loss.
• Comparison of simulated short-term orthostatic responses with existing experimental data.

Main Results:

• Model C was used to study lower body negative pressure (LBNP) and head-up tilt responses.
• Model J was employed for simulating +Gz response.
• Model P was utilized for simulating response to blood loss. (Note: Specific quantitative results comparing models to data are not detailed in the abstract).

Conclusions:

• The study provides an examination of three mathematical models for cardiovascular system (CVS) simulation under orthostatic stress.
• Comparison of model responses to experimental data is crucial for validating their predictive capabilities.
• Further research is needed to establish the accuracy and limitations of these models across various physiological challenges.