Title: IN VITRO 3D HIGH SPEED PIV MEASUREMENTS BEHIND AN AORTIC ARTIFICIAL HEART VALVE
Abstract: Worldwide are performed approximately 225,000 heart valve operation procedures. Various heart valve types have different efficiency, beside others, mostly given by the quality of the flow in all regions across the valve. For the visualization of the flow we employed Stereo High Speed Particle Image Velocimetry (SHSPIV). The monitored flow field was in located past an artificial aortic heart valve. The valve was fixed into an elastic transparent aorta, which was inserted in the modified Vivitro mock loop. SHSPIV measurements show the time evolution of the flow behind a bileaflet valve. A Nd:YLF high-repetition-rate double-cavity laser was combined with a high framerate CMOS cameras which was gained the detailed acquisition of the time-dependent flow structure behind the valve. As expected, the results showed at different time steps showed a low degree of turbulence, symmetric and homogenous flow behavior. In this study a commercially available Vivitro mock-up (VIVITRO SYSTEM INC., Canada) was modified to introduce a new flexible silicone mock aorta. A bileaflet aortic heart valve was fixed in a mock aorta The major aim of the study was to visualize the flow behind the leaflets. The flow behind a bileaflet prosthetic aortic heart valve (PHV) was visualized in the central region of the ascending mock aorta up to 40 mm distal from the valve plane. Typical 3-jet stream flow is observed. The 3rd velocity component is smaller compared to in plane components, however, it reveals the information about secondary flow.