In-silico modeling of a total aritificial heart

Sammanfattning

The total artificial heart is a mechanical circulatory support device used to replace the native heart in patients with severe heart failure while awaiting heart transplantation, with the potential to eventually serve as an alternative to transplantation. Current total artificial hearts are primarily designed for male patients, while female patients may require miniaturized devices. However, the development and testing of full-scale and miniaturized total artificial hearts is mechanically complex, costly and time-consuming. Lumped parameter modeling uses electrical analogies to simulate cardiovascular hemodynamics and interactions with medical devices. In this project, lumped parameter models of a total artificial heart were developed in MATLAB/Simulink, using rigid and compliance-based chamber formulations together with mechanical valve modeling. Two compliance-based models, A and B, were developed using different initialization strategies and chamber calibration. The rigid formulation became unstable in closed-loop cases, whereas the compliance-based models A and B achieved stable operation in both open- and closed-loop configurations. Patient-coupled simulations with both compliance models revealed strong sensitivity to calibration and initialization conditions. A simplified miniaturization study suggested that increased heart rate may partially compensate for reduced pump dimensions in a miniaturized total artificial heart. The obtained models proved useful for the analysis of qualitative hemodynamic trends, and set the basis towards more robust cardiovascular simulations of a total artificial heart.