Thousands of pediatric patients suffering from cardiomyopathy or single ventricular physiologies secondary to debilitating heart defects may benefit from long-term mechanical circulatory support due to the limited number of donor hearts available. This article presents the initial design of a fully implantable centrifugal pediatric ventricular assist device (PVAD) for 2 to 12 year olds. Conventional pump design equations, including a nondimensional scaling approach, enabled performance estimations of smaller scale versions (25 mm and 35 mm impeller diameters) of our adult support VAD. Based on this estimated performance, a computational model of the PVAD with a 35 mm impeller diameter was generated. Employing computational fluid dynamics (CFD) software, the flow paths through the PVAD and overall performance were analyzed for steady state flow conditions. The numerical simulations involved flow rates of 2 to 5 LPM for rotational speeds of 2750 to 3250 RPM and incorporated a k-ε fluid turbulence model with a logarithmic wall function to characterize near-wall flow conditions. The CFD results indicated best efficiency points ranging from 25% to 28%, which correlate well with typical values of blood pumps. The results further demonstrated that the pump could deliver 2 to 5 LPM at 70 to 95 mmHg for desired physiologic conditions in resting 2 to 12 year olds. Scalar stress levels remained below 300 Pa, thereby signifying potentially low levels of hemolysis. Several flow regions in the pump exhibited signs of vortices, retrograde flow, and stagnation points, which require optimization and further study. This CFD model represents a reasonable starting point for future model enhancements, leading to prototype manufacturing and experimental validation.
EmmanouilidesG.C., AllenH.D., RiemenschneiderT.A., GutgesellH.P.Moss and Adams: Heart disease in infants, children, and adolescents including the fetus and young adult.5th Ed, Vol II, Baltimore: Williams & Wilkins, 1995.
2.
GutgesellH.G., MatherneG.P.University of Virginia Medical Center. Department of Pediatrics. Personal Interview. March 2001.
3.
DuncanB.W.Mechanical support for cardiac and respiratory failure in pediatric patients.New York: Marcel Dekker Incorporated, 2001.
4.
NoraJ.J., BergK., NoraA.U.Cardiovascular diseases: Genetics, epidemiology, and prevention.Oxford: Oxford University Press Incorporated, 1991.
WarneckeH., BerdjisF., HennigE., LangeP., SchmittD., HummelM., HetzerR.Mechanical left ventricular support as a bridge to cardiac transplantation in childhood. Eur J Cardiothorac Surg1991; 5: 330–3.
7.
CostaR.J., ChardR.B., NunnG.R., CartmillT.B.Ventricular assist devices in pediatric cardiac surgery. Ann Thorac Surg1995; 60(suppl): S536–8.
AllaireP.E., KimH.C., MaslenE.H., OslenD.B., BearnsonG.B.Prototype continuous flow ventricular assist device supported on magnetic bearings. Artif Organs1996; 20: 582–90.
14.
HiltonE.F., AllaireP.E., BalohM.J., MaslenE.H., BearnsonG.B., KhanwilkarP., OlsenD.B.Magnetic suspension controls for a new continuous flow ventricular assist device. Proceedings of the American Society of Artificial Internal Organs; 1997 May 1-3; Atlanta, GA.
15.
KhanwilkarP., OlsenD.B., BearnsonG.B., AllaireP.E., MaslenE.H., FlankR., LongJ.Using hybrid magnetic bearings to completely suspend the impeller of a ventricular assist device. Artif Organs1996; 20: 597–604.
16.
BurgeenG.W., AntakiJ.F., WuZ.J., HolmesA.J.Computational fluid dyanmics as a development tool for rotary blood pumps. Artif Organs2001; 25: 336–40.
17.
MasuzawaT., TsukiyaT., EndoS., TatsumiE., TaenakaY., TakanoH., YamaneT., NishidaM., AsztalosB., MiyazoeY., ItoK., SawairiT., KonishiY.Development of design methods for a centrifugal blood pump with a fluid dynamic approach: Results in hemolysis tests. Artif Organs1999; 23: 757–61.
18.
MiyazoeY., SawairiT., ItoK., KonishiY., YamaneT., NishidaM., AsztalosB., MasuzawaT., TsukiyaT., EndoS., TaenakaY.Computational fluid dyanmics to establish the design process of a centrifugal blood pump: Second report. Artif Organs1999; 23: 762–8.
19.
QianY., BertramC.Computational fluid dynamics analysis of hydrodynamic bearings of the VentrAssist Rotary blood pump. Artif Organs2000; 24: 488–91.
20.
SprayT.Demographics of heart failure in the pediatric population. 48th Annual ASAIO Conference, New York, June 2001.
21.
SramekB.B., HraskaV.Normal values of hemodynamic parameters for neonatal and pediatric patients. 5th Brazilian Congress of Critical Care Medicine, 1998.
22.
KarassikI.J., KrutzschW.C., FraserW.H., MessinaJ.P.Pump Handbook, 2nd Edition. New York: McGraw-Hill Book Company, 1986.
23.
StepanoffA.J.Centrifugal and axial flow pumps, 2nd Edition. New York: Krieger Publishing Company, 1957.
24.
DayS.W., McDanielJ.C., WoodH.G., AllaireP.E., LandrotN., CurtasA.Particle image velocimetry measurements of blood velocity in a continuous flow ventricular assist device. ASAIO J2001; 47: 406–11.
SmithW.A., AllaireP., AntakiJ., ButlerK.C., KinkT., LoreeH., ReulH., VeresJ.The collected non-dimensional performance of rotary dynamic blood pumps. Draft 8 Feb 99. Personal Communication with Paul Allaire in March 2001.
27.
AndersonJ.B., WoodH.G., AllaireP.E., McDanielJ.C., OlsenD.B., BearnsonG.Numerical studies of blood shear and washing in a continuous flow ventricular assist device. ASAIO J2000; 46: 486–94.
28.
AndersonJ.B., WoodH.G., AllaireP.E., BearnsonG., KhanwilkarP.Computational flow study of the continuous flow ventricular assist device, prototype #3 blood pump. Artif Organs2000; 24: 377–85.
29.
LemirePP, DaySW, McDanielJC, WoodHG. A quantitative oil dot streak method for measuring near-wall shear stresses applied to the Heartquest maglev LVAD. Proceedings of the ASME International Mechanical Engineering Congress and Exposition. Advances in Bioengineering, vol. 54. November 17-22, 2002 New Orleans, LA.
30.
BludszuweitC.Model for general mechanical blood damage prediction. Artif Organs1995; 19: 583–9.
31.
AllaireP.E., WoodH.G., AwadR.S., OlsenD.B.Blood flow in a continuous flow ventricular assist device. Artif Organs1999; 23: 769–73.
32.
TakiuraK., MasuzawaT., EndoS.Development of design methods of a centrifugal blood pump with in vitro tests, flow visualization, and computational fluid dynamics: result in hemolysis tests. Artif Organs1998; 22: 393–8.
33.
HuangC.R., FabisiakW.A rheological equation characterizing both the time dependent and the steady state viscosity of whole human blood. AIChE Symposium Series1978; 19–21.
34.
WellR.E., MerrillE.W.Shear rate dependence of viscosity of whole blood and plasma. Science1961; 133: 763–4.
35.
BerneR.M., LevyM.N.Physiology, 4th Edition. St. Louis: Mosby Incorporated, 1998.
36.
ApelJ., NeudelF., ReulH.Computational fluid dynamics and experimental validation of a microaxial blood pump. ASAIO J2001; 47: 552–8.
PaulR., ApelJ., KlausS., SchugnerF., SchwindkeP., ReulH.Shear stress related blood damage in laminar couette flow. Artif Organs2003; 27: 517–29.
42.
LemireP.P., DayS.W., McDanielJ.C., WoodH.G.The application of quantitative oil streaking to the HeartQuest LVAD. November 2002. 9th Congress of the International Society for Rotary Blood Pumps.
