A computer controlled mock circulatory system for mono- and biventricular assist device testing

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology

Background:

• In vitro testing of heart assist devices is crucial for clinical application and training.
• Accurately reproducing the complex interactions between assist devices, the ventricle, and the circulatory network remains a challenge.

Purpose of the Study:

• To develop and validate a mock circulatory system for comprehensive in vitro testing of heart assist devices.
• To analyze the working point on the pressure-volume (p-v) plane, reflecting device-ventricle-circulation interactions.

Main Methods:

• A closed-loop mock circulatory system simulating systemic and pulmonary circulation was created.
• Arterial trees were modeled using adjustable windkessels, and the heart's Starling's law was simulated with a variable elastance model.
• Software controlled and monitored circulatory parameters, enabling simulation of physiological, pathological, and assist device-assisted conditions.

Main Results:

• The system successfully demonstrated behavior under preload and afterload variations.
• Physiological, pathological (altered end-systolic pressure-volume relationship - ESPVR), and left ventricular assist device (LVAD) assisted conditions were accurately reproduced.
• The impact of assist device control strategies on ventricular work cycles and hemodynamic variables was evaluated on the p-v plane.

Conclusions:

• The developed mock circulatory system provides a valuable platform for evaluating heart assist devices and their effects on ventricular energetics.
• Further improvements are needed, particularly in modeling the aorta, to accommodate devices like the intra-aortic balloon pump (IABP).