Cardiovascular modelling for medical device testing

The cardiorespiratory model reproduces human physiology with a high level of fidelity. It is a lumped parameter model including a representation of atria, ventricles, pulmonary and systemic circulations, autonomic controls, metabolic peripheral control, ventilation and gas exchange in tissues and lungs.

The simulator is developed in LabVIEW language and is organized in several modules:

• - Physiological model: this is the internal core representing the circulation as described above. It reproduces flow and pressure profiles in the heart and in the vessels.
• - Diseases: this module consists in a set of parameters values to be fed into the physiological model for the representation of one or multiple diseases with different levels of severity. These diseases were validated using the ACCF/AHA medical guidelines so to make sure the output (cardiac output, wedge pressure, arterial pressure etc.) was in the correct range.
• - Therapies: this modules permits to simulate the effects of pharmacological and device therapies.
• - Self-tuning module: this module automatically tunes the simulator to a patient’s specific condition. The user inserts patient’s data and a recursive algorithm tunes the simulator to the desired hemodynamic condition.
• - Exercise module: it reproduces exercise physiology both in healthy and heart failure conditions in terms of chronotropic and inotropic response, vasodilation, increase in ventilation.

The laboratory of cardiac surgery is also equipped with a “hybrid” simulator (HS), developed in cooperation with the Nalecz Institute of Biocybernetics and Biomedical Engineering of the Polish Academy of Sciences. This is an innovative type of simulators that combines computer modeling and mock loop connected each other in LabVIEW real time. This simulator is largely used in the pre-clinical test of medical devices as: ventricular assist devices, vascular grafts, heart valves, total artificial hearts etc.