The hemodynamic performance of artificial aortic valves (AVs) and the probability for structural valve deterioration can be linked to the valve kinematics. Comparability among different studies is limited because of variations in the experimental setups and physiologic boundary conditions. This study presents results of kinematic measurements of bioprosthetic and mechanical AVs that were tested in an identical experimental setting such that they can be directly compared with each other. The kinematics of AVs is typically presented in the form of the geometric orifice area and its temporal evolution. These parameters cannot capture asynchronous leaflet motion and out-of-plane leaflet velocity. In this work, each leaflet was tracked individually for a more detailed understanding of the leaflet kinematics, asynchronous leaflet motion, and leaflet tip velocities. A bioprosthetic valve, Edwards INTUITY (EINT), and two mechanical valves, Medtronic ADVANTAGE (MADV) and a Lapeyre-Triflo FURTIVA (TFUR), were tested in a compliant model of the aortic root in a physiologic flow loop. TFUR and MADV opened alike with maximum leaflet tip velocities of 0.77 and 0.66 m/s, respectively. The opening of EINT showed significantly higher local in-plane leaflet velocities of more than 2 m/s. EINT and TFUR exhibited similar early and slow closure. MADV closed significantly later with increased velocity. TFUR had a median maximum leaflet tip velocity of 0.39 m/s during valve closure and that of MADV was 0.83 m/s, whereas EINT exhibited a median maximum local in-plane leaflet velocity of 0.37 m/s. EINT experienced leaflet fluttering during systole with a flapping frequency of 36 Hz.

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Aortic valve disease is one of the leading forms of complications in the cardiovascular system. The failing native aortic valve is routinely surgically replaced with a bioprosthesis. However, insufficient durability of bioprosthetic heart valves often requires reintervention. Valve degradation can be assessed by an analysis of the blood flow characteristics downstream of the valve. This is cost and labor intensive using clinical methodologies and is performed infrequently. The integration of consumer smartphones and implantable blood flow sensors into the data acquisition chain facilitates remote management of patients that is not limited by access to clinical facilities. This article describes the characteristics of an implantable magnetic blood flow sensor which was optimized for small size and low power consumption to allow for batteryless operation. The data is wirelessly transmitted to the patient's smartphone for in-depth processing. Tests using three different experimental setups confirmed that wireless and batteryless blood flow recording using a magnetic flow meter technique is feasible and that the sensor system is capable of monitoring the characteristic flow downstream of the valve.