A New Cardiovascular Mock Loop Driven by Novel Active Capacitance in Normal and Abnormal Conditions.

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Simulation

Background:

• Hybrid mock circulatory loops (hMCL) are vital for studying cardiovascular diseases (CVD) due to their flexibility and control.
• Existing hMCLs have limitations in fully replicating complex cardiovascular dynamics and autoregulation.
• Investigating CVD mechanisms requires advanced simulation tools that accurately model physiological responses.

Purpose of the Study:

• To introduce a novel hMCL design and control strategy.
• To develop a new left ventricle volume-elastance (LVVE) equation integrating the Frank-Starling mechanism (FSM) and left ventricle contractility (LVC).
• To enhance the physiological fidelity of hMCL simulations for various cardiovascular conditions.

Main Methods:

• Developed a novel LVVE equation linking left ventricular volume (LVV) and LVC dynamically.
• Implemented discrete feedback linearization for real-time proportional valve control.
• Achieved FSM emulation by tracking reference LVV values without predefined functions.
• Validated the hMCL through numerical simulations and comparison with existing research.

Main Results:

• The integrated LVVE equation accurately replicated FSM responses under conditions like aortic stenosis (AS), systemic vascular resistance (SVR), and heart rate (HR) variations.
• The hMCL demonstrated enhanced physiological fidelity in simulating normal and abnormal cardiovascular states.
• Increasing HR was shown to enhance LVC and maintain physiological pressures, correlating with decreased LVV, aligning with human data and FSM principles.
• Stability proofs for the discrete closed-loop hMCL were established.

Conclusions:

• The novel hMCL with integrated LVVE significantly advances physiological simulation capabilities.
• This approach enhances the study of complex cardiovascular dynamics and diseases.
• The hMCL provides a versatile platform for investigating critical cardiovascular scenarios with improved accuracy.