Development of a high-fidelity biorobotic cardiovascular in vitro simulator

Abstract

The complex motion of the beating heart is accomplished by the spatial arrangement of contracting cardiomyocytes with varying orientation across transmural layers, which is difficult to imitate in organic or synthetic models. The anatomical details of intracardiac structures (such as papillary muscles, chordae tendineae, ventricular trabeculae, valves, moderator bands) are highly complex and challenging to replicate using current manufacturing methods. In this thesis, I propose a biorobotic hybrid heart that preserves organic intracardiac structures and mimics cardiac motion by replicating the cardiac myofiber architecture of the left ventricle. The heart model is composed of organic endocardial tissue from a preserved explanted heart with intact intracardiac structures and an active synthetic myocardium that drives the motion of the heart. The active soft tissue mimic is then coupled to the organic endocardial tissue in a helical fashion to achieve the complex three-dimensional fiber architecture. The resulting biorobotic hybrid heart simulates the contractile motion of the native heart with a faithful representation of endocardial tissue anatomy.

This heart model is connected to a mock circulatory loop to represent the human circulatory system where pulsatile flow, and hemodynamic parameters such as flow and pressure in the heart and vasculature are recapitulated using our biorobotic heart as the active pump. Additional cardiac parameters such as heart contractility, heart rate, flow resistance and compliance can be adjusted to recreate physiological and pathological hemodynamics. We demonstrate a biorobotic cardiovascular in vitro simulator that recapitulates internal cardiac structures, ventricular motion and hemodynamics. We then mimic a pathological condition (acute mitral regurgitation) with the heart model and demonstrate various interventions (such as surgical repair, replacement and minimally invasive repair procedure) with collaborating cardiac surgeons. Overall, the biorobotic cardiovascular in vitro simulator may be used as a high-fidelity cardiovascular benchtop model for the development of intracardiac devices, thus reducing the overall number of animals used in preclinical and regulatory testing.