TY - JOUR
T1 - The hemodynamics of the Berlin pulsatile VAD and the role of its MHV configuration
AU - Avrahami, Idit
AU - Rosenfeld, Moshe
AU - Einav, Shmuel
N1 - Funding Information:
This research was partially supported by a grant from G.I.F., the German-Israeli Foundation for Scientific Research and Development and by the Fritz Brann Fellowship, the Israel Science Foundation, the Joseph Drown Foundation, and the Berman Trust.
PY - 2006/9
Y1 - 2006/9
N2 - The 3D flow in a model of the Berlin ventricular assist device (VAD) chamber with monoleaflet valves placed in S-shape conduits was simulated numerically. The blood flow dynamics were described in terms of flow patterns, velocity, pressure, and shear stress. The hemodynamic properties and the VAD's potential risk for thrombosis were evaluated in terms of mixing and washout properties, and global estimations of platelet level of activation (LOA). In order to evaluate the role of valves on the flow in the chamber, the flow in a model with bileaflet valves in straight conduits was simulated and compared with the original case. The results showed that in both models a large rotating flow was developed in the chamber during filling. This vortex filled the entire chamber and moved constantly up to the peak ejection phase, resulting in relatively low shear stress (up to 0.4 Pa) and no lasting stagnation regions. Significant shear stresses were found near the valves with higher values near the outlet valve in both models. The configuration of valves and conduits had a large effect on VAD washout and mixing properties, with advantage to the bileaflet model. However, since the bileaflet valves exhibited higher shear stresses, higher LOA were found for the bileaflet model.
AB - The 3D flow in a model of the Berlin ventricular assist device (VAD) chamber with monoleaflet valves placed in S-shape conduits was simulated numerically. The blood flow dynamics were described in terms of flow patterns, velocity, pressure, and shear stress. The hemodynamic properties and the VAD's potential risk for thrombosis were evaluated in terms of mixing and washout properties, and global estimations of platelet level of activation (LOA). In order to evaluate the role of valves on the flow in the chamber, the flow in a model with bileaflet valves in straight conduits was simulated and compared with the original case. The results showed that in both models a large rotating flow was developed in the chamber during filling. This vortex filled the entire chamber and moved constantly up to the peak ejection phase, resulting in relatively low shear stress (up to 0.4 Pa) and no lasting stagnation regions. Significant shear stresses were found near the valves with higher values near the outlet valve in both models. The configuration of valves and conduits had a large effect on VAD washout and mixing properties, with advantage to the bileaflet model. However, since the bileaflet valves exhibited higher shear stresses, higher LOA were found for the bileaflet model.
KW - Computational fluid dynamics
KW - Mechanical heart valves
KW - Mixing and washout properties
KW - Platelet level of activation
KW - Pulsatile VAD
KW - Ventricular assist device
UR - http://www.scopus.com/inward/record.url?scp=33749011474&partnerID=8YFLogxK
U2 - 10.1007/s10439-006-9149-x
DO - 10.1007/s10439-006-9149-x
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C2 - 16838127
AN - SCOPUS:33749011474
SN - 0090-6964
VL - 34
SP - 1373
EP - 1388
JO - Annals of Biomedical Engineering
JF - Annals of Biomedical Engineering
IS - 9
ER -