Comparison of in vitro flows past a mechanical heart valve in anatomical and axisymmetric aorta models

Use of 3D anatomical models in mock circulatory loops for cardiac medical device testing

“…11,25,36,38,45,54,63,64,[67][68][69][70]73 In these cases, ventricular blood flow was simulated either as a generic sinusoidal waveform or using pulsatile pumps that could change the stroke volume, heart rate and systolediastole ratio. More sophisticated MCLs considered either part 12,[16][17][18][19]22,23,[30][31][32][33][34][35]46,48,52,60,61,65,66,74 or all the cardiovascular system 13,14,29,39,40,49,50,53,75 by including compliance chambers and variable resistances or, in few cases, by simulating it computationally.…”

“…It is a rapid and low-cost process that enables the generation of complex geometries in materials such as liquid photosensitive resins and polymers. Typical applications of rigid 3D models are the investigation of a pathology, 12 the surgical planning, 13,14 and students' training. 15,16 When a rigid model is connected to a MCL, it can be used to characterize flow patterns in the considered anatomy.…”

“…This is particularly useful when testing MDs such as ventricular assist devices (VAD) 17,18 or valves. 12,19 However, rigid materials can only replicate the geometry of the anatomical site of interest, lacking the representation of its mechanical properties. To reproduce cardiac/vessel's wall stiffness and to assure a correct representation of both pressures and volumes in the considered 3D model, a compliant material is needed.…”

Hydrodynamic Noise of Pulsating Jets through Bileaflet Mechanical Mitral Valve

“…Therefore, the fine structure of blood flow through the mechanical heart valves is investigated in the laboratory with the help of miniature sensors and complexes for detecting the movement of labelled particles with an increased spatial and temporal resolution [18,19]. Several complex experimental setups that were used for hemodynamic and hydrodynamic studies have been described in the literature [20][21][22].…”

Fluid dynamics and blood damage in the dilated ascending aorta after mechanical prosthetic valve implantation: an in vitro study

“…The cumulative effect at the N-th time step, t N , on a particle released at X 0 at the beginning of the systole is estimated by the summation: where, as above stated, a, b and C are empirically determined constants. We used the values a = 0.785, b = 2.416 and C = 3.62•10 -5 proposed by Giersiepen et al (1990) for haemolysis, and the values a = 1.3198, b = 0.6256 and C = 1•10 -5 proposed by Nobili et al (2008) for the estimation of the platelet activation (in both cases the numeric values of the constants hold for shear stresses measured in Pa and time intervals in seconds); X 0 , t = 1 2 ( 1 X 0 , t − 2 X 0 , t ) is the maximum shear stress on the blood cell, while σ 1 (X 0 ,t) and σ 2 (X 0 ,t) indicate, respectively, the maximum and minimum principal stress (Haya and Tavoularis 2017) at the location experienced at the time t by the fluid particle, initially released in X 0 and d s0 is the initial mechanical dose (we assumed d s0 = 0).…”