Abstract
Rotodynamic blood pumps (also known as rotary or continuous flow blood pumps) are commonly evaluated in vitro under steady flow conditions. However, when these devices are used clinically as ventricular assist devices (VADs), the flow is pulsatile due to the contribution of the native heart. This study investigated the influence of this unsteady flow upon the internal hemodynamics of a centrifugal blood pump. The flow field within the median axial plane of the flow path was visualized with particle image velocimetry (PIV) using a transparent replica of the Levacor VAD. The replica was inserted in a dynamic cardiovascular simulator that synchronized the image acquisition to the cardiac cycle. As compared to steady flow, pulsatile conditions produced periodic, transient recirculation regions within the impeller and separation in the outlet diffuser. Dimensional analysis revealed that the flow characteristics could be uniquely described by the non-dimensional flow coefficient (Φ) and its time derivative (\(\dot{\Phi }\)), thereby eliminating impeller speed from the experimental matrix. Four regimes within the Φ–\(\dot{\Phi }\) plane were found to classify the flow patterns, well-attached or disturbed. These results and methods can be generalized to provide insights for both design and operation of rotodynamic blood pumps for safety and efficacy.
Similar content being viewed by others
References
Amacher, R., G. Ochsner, and M. Schmid Daners. Synchronized pulsatile speed control of turbodynamic left ventricular assist devices: review and prospects. Artif. Organs. 2014. doi:10.1111/aor.12253. [Epub ahead of print].
Amin, D. V., J. F. Antaki, P. Litwak, D. Thomas, Z. Wu, Y. C. Yu, S. Choi, J. R. Boston, and B. P. Griffith. Controller for an axial-flow blood pump. Biomed. Instrum. Technol. 31(5):483–487, 1997.
Antaki, J. F., O. Ghattas, G. W. Burgreen, and B. He. Computational flow optimization of rotary blood pump components. Artif. Organs 19(7):608–615, 1995.
Antaki, J. F., C. G. Diao, F. J. Shu, J. C. Wu, R. Zhao, and M. V. Kameneva. Microhaemodynamics within the blade tip clearance of a centrifugal turbodynamic blood pump. Proc. Inst. Mech. Eng. H. 222(4):573–581, 2008.
Arvand, A., N. Hahn, M. Hormes, M. Akdis, M. Martin, and H. Reul. Comparison of hydraulic and hemolytic properties of different impeller designs of an implantable rotary blood pump by computational fluid dynamics. Artif. Organs 28(10):892–898, 2004.
Burgreen, G. W., and J. F. Antaki. CFD-based design optimization of a three-dimensional rotary blood pumps. In: Proc 6th Symp on Multidisciplinary Analysis and Optimization; Bellevue, WA, 1996.
Burgreen, G. W., J. F. Antaki, Z. J. Wu, and A. J. Holmes. Computational fluid dynamics as a development tool for rotary blood pumps. Artif. Organs 25(5):336–340, 2001.
Busemann, A. Das Förderhöhenverhältnis Radialer Kreiselpumpen mit logarithmisch-spiraligen Schaufeln. ZAMM 8:372–374, 1928.
Chiu, W. C., M. J. Slepian, and D. Bluestein. Thrombus formation patterns in the HeartMate II ventricular assist device: clinical observations can be predicted by numerical simulations. ASAIO J. 60(2):237–240, 2014. doi:10.1097/MAT.0000000000000034.
Day, S. W., and J. C. McDaniel. PIV measurements of flow in a centrifugal blood pump: steady flow. J. Biomed. Eng. 127:244–253, 2005.
Day, S. W., and J. C. McDaniel. PIV measurements of flow in a centrifugal blood pump: time-varying flow. J. Biomed. Eng. 127:254–263, 2005.
Deutsch, S., J. M. Tarbell, K. B. Manning, G. Rosenberg, and A. A. Fontaine. Experimental fluid mechanics of pulsatile artificial blood pumps. Annu. Rev. Fluid Mech. 38:65–86, 2006.
Hariharan, P., M. Giarra, V. Reddy, S. W. Day, K. Manning, S. Deutsch, S. F. C. Stewart, M. R. Myers, M. Berman, G. W. Burgreen, E. G. Paterson, and R. A. Malinauskas. Multilaboratory particle image velocimetry analysis of the FDA benchmark nozzle model to support validation of computational fluid dynamics simulations. J. Biomech. Eng. 133(4):041002, 2011. doi:10.1115/1.4003440.
Hetzer, R., M. Loebe, E. V. Potapov, Y. Weng, B. Stiller, E. Hennig, V. Alexi-Meskishvili, and P. E. Lange. Circulatory support with pneumatic paracorporeal ventricular assist device in infants and children. Ann. Thorac. Surg. 66:1498–1506, 1998.
Jahren, S. E., G. Ochsner, F. Shu, R. Amacher, J. F. Antaki, and S. Vandenberghe. Analysis of pressure head-flow loops of pulsatile rotodynamic blood pumps. Artif. Organs. Jul 25 2013. doi:10.1111/aor.12139.
Kirklin, J. K., D. C. Natftel, R. L. Kormos, L. W. Stevenson, F. D. Pagani, M. A. Miller, J. T. Baldwin, and J. B. Young. Fifth INTERMACS annual report: risk factor analysis from more than 6,000 mechanical circulatory support patients. J. Heart Lung Transp. 32(2):141–156, 2013.
Pirbodaghi, T., S. Axiak, A. Weber, T. Gempp, and S. Vandenberghe. Pulsatile control of rotary blood pumps: does the modulation waveform matter? J. Thorac. Cardiovasc. Surg. 144(4):970–977, 2012.
Shepard, D. G. Principles of turbomachinery. McMillan, 1956. ISBN 0-471-85546-4.
Shu, F. Flow physics of indeterminate origin nozzle jets and passive control of sprays. PhD thesis, Purdue University, West Lafayette, IN, 2005.
Shu, F., S. Vandenberghe, and J. F. Antaki. The importance of dQ/dt on the flow field in a turbodynamic pump with pulsatile flow. Artif. Organs 33(9):757–762, 2009.
Starling, R. C., N. Moazami, S. C. Silvestry, G. Ewald, J. G. Rogers, C. A. Milano, J. E. Rame, M. A. Acker, E. H. Blackstone, J. Ehrlinger, L. Thuita, M. M. Mountis, E. G. Soltesz, B. W. Lytle, and N. G. Smedira. Unexpected abrupt increase in left ventricular assist device thrombosis. N. Engl. J. Med. 370(1):33–40, 2014. doi:10.1056/NEJMoa1313385.
Stewart, S. F. C., E. G. Paterson, G. W. Burgreen, P. Hariheren, M. Giarra, V. Reddy, S. W. Day, K. B. Manning, S. Deutrch, M. R. Berman, M. R. Myers, and R. A. Malinauska. Assessment of CFD performance in simulations of an idealized medical device: results of FDA’s first computational interlaboratory study. Cardiovasc. Eng. Technol. 3(2):139–160, 2012.
Tsukiya, T., Y. Taenaka, E. Tatsumi, and H. Takano. Visualization study of the transient flow in the centrifugal blood pump impeller. ASAIO J. 48(4):431–436, 2002.
Vandenberghe, S., P. Segers, J. F. Antaki, B. Meyns, and P. R. Verdonck. Hemodynamic modes of ventricular assist with a rotary blood pump: continuous, pulsatile, and failure. ASAIO J. 51(6):711–718, 2005.
Wu, Z. J., J. F. Antaki, G. W. Burgreen, K. C. Butler, D. C. Thomas, and B. P. Griffith. Fluid dynamic characterization of operating conditions for continuous flow blood pumps. ASAIO J. 45(5):442–449, 1999.
Wu, Z. J., J. F. Antaki, W. R. Wagner, T. A. Snyder, B. E. Paden, and H. S. Borovetz. Elimination of adverse leakage flow in a miniature pediatric centrifugal blood pump by computational fluid dynamics-based design optimization. ASAIO J. 51(5):636–643, 2005.
Wu, Z. J., R. K. Gottlieb, G. B. Burgreen, J. A. Holmes, D. C. Borzelleca, M. V. Kameneva, B. P. Griffith, and J. F. Antaki. Investigation of fluid dynamics within a miniature mixed flow blood pump. Exp. Fluids 31(6):615–629, 2001.
Acknowledgments
The authors would like to thank WorldHeart Corporation for providing the transparent pump. This project was supported in part through NIH Grant R01 HL089456.
Conflict of interest
The authors have no conflict of interest in this research.
Ethical Standards
No human or animal experiments were involved in this work.
Author information
Authors and Affiliations
Corresponding author
Additional information
Associate Editor Ajit P. Yoganathan oversaw the review of this article.
Rights and permissions
About this article
Cite this article
Shu, F., Vandenberghe, S., Brackett, J. et al. Classification of Unsteady Flow Patterns in a Rotodynamic Blood Pump: Introduction of Non-Dimensional Regime Map. Cardiovasc Eng Tech 6, 230–241 (2015). https://doi.org/10.1007/s13239-015-0231-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13239-015-0231-0