Experimental validation of a cardiac simulator for in vitro evaluation of prosthetic heart valves

Abstract

ObjectiveThis work describes the experimental validation of a cardiac simulator for three heart rates (60, 80 and 100 beats per minute), under physiological conditions, as a suitable environment for prosthetic heart valves testing in the mitral or aortic position.MethodsIn the experiment, an aortic bileaflet mechanical valve and a mitral bioprosthesis were employed in the left ventricular model. A test fluid of 47.6% by volume of glycerin solution in water at 36.5ºC was used as blood analogue fluid. A supervisory control and data acquisition system implemented previously in LabVIEW was applied to induce the ventricular operation and to acquire the ventricular signals. The parameters of the left ventricular model operation were based on in vivo and in vitro data. The waves of ventricular and systemic pressures, aortic flow, stroke volume, among others, were acquired while manual adjustments in the arterial impedance model were also established.ResultsThe acquired waves showed good results concerning some in vivo data and requirements from the ISO 5840 standard.ConclusionThe experimental validation was performed, allowing, in future studies, characterizing the hydrodynamic performance of prosthetic heart valves.

In Vitro Hydrodynamic Evaluation of a Scaffold for Heart Valve Tissue Engineering

“…The LVM was established for a heart rate of 60 bpm with a systolic duration of 400 ms , a stroke volume of 70 mL, and an end‐diastolic volume of 120 mL. The aortic pressure (AoP) was increased successively, until it reached the range of 80–120 mm Hg , as shown in Fig. B.…”

In Vitro 2D PIV Measurements and Related Aperture Areas of Tricuspid Bioprosthetic Mitral Valves at the beginning of Diastole

“…Two stented mitral bioprostheses of bovine pericardium a 31 mm diameter) and an aortic bileaflet mechanical valve (27 mm diameter; CarboMedics) were used in the cardiac simulator at Escola Politécnica of the University of Sao Paulo in Brazil. The instrumentation, control and data acquisition (DAQ) module were described previously (13).…”

“…The phase-locked PIV measurements at the beginning of diastole were only possible by the synchrony established between the cardiac simulator and the PIV system, using a digital trigger (TTL, 5 Vdc) (10, 13). The trigger for the beginning of diastole (Td) was established from the control of the LVM (actuated by a servomotor with an encoder), for the same silicone membrane deflection (see Fig.…”

Model-based management of cardiovascular failure: Where medicine and control systems converge

“…In particular, such measures could be linked to responses to therapy using either pharmacodynamics (PD) style models [27][28][29], as done in areas such as glycemic control [14,[30][31][32][33][34], sedation management [35][36][37], and anaesthesia [38][39][40], or to statistical models or receiver operating characteristic curves, as frequently used in medicine [41][42][43]. Computational fluid dynamics (CFD) models can also facilitate complex surgical treatment like valve replacement [44,45]. In either case, there is the complete link from measurements to effective metrics for making personalised, patient-specific decisions, all of which defines an automated, feedback controlled control system.…”