Computational and Experimental Evaluation of the Fluid Dynamics and Hemocompatibility of the CentriMag Blood Pump

Zhang, Juntao; Gellman, Barry; Koert, Andrew; Dasse, Kurt A.; Gilbert, Richard J.; Griffith, Bartley P.; Wu, Zhongjun J.

doi:10.1111/j.1525-1594.2006.00203.x

Cited by 141 publications

(119 citation statements)

References 14 publications

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“…The magnetic flux signals were then recorded with the pump working under the actual operating conditions and later calibrated using the curve to reveal the actual impeller positions. Two of the VADs in this study have been analyzed by our group before [39,43], however, the models and calculations presented were all redone to ensure consistency between the devices.…”

Section: Methodsmentioning

confidence: 99%

A Quantitative Comparison of Mechanical Blood Damage Parameters in Rotary Ventricular Assist Devices: Shear Stress, Exposure Time and Hemolysis Index

Fraser

Zhang

Taşkın

et al. 2012

Journal of Biomechanical Engineering

Self Cite

299

378

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Ventricular assist devices (VADs) have already helped many patients with heart failure but have the potential to assist more patients if current problems with blood damage (hemolysis, platelet activation, thrombosis and emboli, and destruction of the von Willebrand factor (vWf)) can be eliminated. A step towards this goal is better understanding of the relationships between shear stress, exposure time, and blood damage and, from there, the development of numerical models for the different types of blood damage to enable the design of improved VADs. In this study, computational fluid dynamics (CFD) was used to calculate the hemodynamics in three clinical VADs and two investigational VADs and the shear stress, residence time, and hemolysis were investigated. A new scalar transport model for hemolysis was developed. The results were compared with in vitro measurements of the pressure head in each VAD and the hemolysis index in two VADs. A comparative analysis of the blood damage related fluid dynamic parameters and hemolysis index was performed among the VADs. Compared to the centrifugal VADs, the axial VADs had: higher mean scalar shear stress (sss); a wider range of sss, with larger maxima and larger percentage volumes at both low and high sss; and longer residence times at very high sss. The hemolysis predictions were in agreement with the experiments and showed that the axial VADs had a higher hemolysis index. The increased hemolysis in axial VADs compared to centrifugal VADs is a direct result of their higher shear stresses and longer residence times. Since platelet activation and destruction of the vWf also require high shear stresses, the flow conditions inside axial VADs are likely to result in more of these types of blood damage compared with centrifugal VADs.

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Section: Methodsmentioning

confidence: 99%

A Quantitative Comparison of Mechanical Blood Damage Parameters in Rotary Ventricular Assist Devices: Shear Stress, Exposure Time and Hemolysis Index

Fraser

Zhang

Taşkın

et al. 2012

Journal of Biomechanical Engineering

Self Cite

299

378

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“…40 These levels are well within the range of shear stress reported for the CentriMag centrifugal pump. 41 In fact, the CentriMag pump has been shown to significantly reduce high-molecular-weight vWF after 3 hours in a recirculating in vitro test loop. 42 Centrifugal and roller pumps generate flow by different mechanisms.…”

Section: Discussionmentioning

confidence: 99%

Roller and Centrifugal Pumps

et al. 2015

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Centrifugal pumps are increasingly used for extracorporeal membrane oxygenation (ECMO) rather than roller pumps. However, shear forces induced by these types of continuousflow pumps are associated with acquired von Willebrand factor deficiency and bleeding complications. This study was undertaken to compare adverse bleeding complications with the use of centrifugal and roller pumps in patients on prolonged ECMO support. The records of all adult ECMO patients from June 2002 to 2013 were retrospectively reviewed using the University of Michigan Health System database and the Extracorporeal Life Support Organization registry, focusing on patients supported for at least 5 days. Ninety-five ECMO patients met criteria for inclusion (48 roller vs. 47 centrifugal pump). Indications included pulmonary (79%), cardiac (15%), and extracorporeal cardiopulmonary resuscitation (6%), without significant difference between the two groups. Despite lower heparin anticoagulation (10.9 vs. 13.7 IU/kg/hr) with centrifugal pumps, there was a higher incidence of nonsurgical bleeding (gastrointestinal, pulmonary, and neurological) in centrifugal pump patients (26.1 vs. 9.0 events/1,000 patient-days, p = 0.024). In conclusion, in our historical comparison, despite reduced anticoagulation, ECMO support using centrifugal pumps was associated with a higher incidence of nonsurgical bleeding. The mechanisms behind this are multifactorial and require further investigation.

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“…Shear stress and zones of stagnation and recirculation are associated with suboptimal fl ow which result in activation of red blood cells, white blood cells and platelets [8][9][10] . The damage is most prominent in a low-fl ow highresistance setting.…”

Section: Mecc Equipmentmentioning

confidence: 99%