Computational design and experimental performance testing of an axial-flow pediatric ventricular assist device.
The Virginia Artificial Heart Institute continues to design and develop an axial-flow pediatric ventricular assist device (PVAD) for infants and children in the United States. Our research team has created a database to track potential PVAD candidates at the University of Virginia Children's Hospital. The findings of this database aided with need assessment and design optimization of the PVAD. A numerical analysis of the optimized PVAD1 design (PVAD2 model) was also completed using computational fluid dynamics (CFD) to predict pressure-flow performance, fluid force estimations, and blood damage levels in the flow domain. Based on the PVAD2 model and after alterations to accommodate manufacturing, a plastic prototype for experimental flow testing was constructed via rapid prototyping techniques or stereolithography. CFD predictions demonstrated a pressure rise range of 36-118 mm Hg and axial fluid forces of 0.8-1.7 N for flows of 0.5-3 l/min over 7000-9000 rpm. Blood damage indices per CFD ranged from 0.24% to 0.35% for 200 massless and inert particles analyzed. Approximately 187 (93.5%) of the particles took less than 0.14 seconds to travel completely through the PVAD. The mean residence time was 0.105 seconds with a maximum time of 0.224 seconds. Additionally, in a water/glycerin blood analog solution, the plastic prototype produced pressure rises of 20-160 mm Hg for rotational speeds of 5960 +/- 18 rpm to 9975 +/- 31 rpm over flows from 0.5 to 4.5 l/min. The numerical results for the PVAD2 and the prototype hydraulic testing indicate an acceptable design for the pump, represent a significant step in the development phase of this device, and encourage manufacturing of a magnetically levitated prototype for animal experiments.
Throckmorton
Amy L
AL
Department of Biomedical Engineering, Virginia Artificial Heart Institute, University of Virginia, Charlottesville, VA, USA.
Lim
D Scott
DS
McCulloch
Michael A
MA
Jiang
Wei
W
Song
Xinwei
X
Allaire
Paul E
PE
Wood
Houston G
HG
Olsen
Don B
DB
D000293:Adolescent; D001775:Blood Circulation; D001794:Blood Pressure; D001830:Body Surface Area; D002648:Child; D002675:Child, Preschool; D019295:Computational Biology; D003198:Computer Simulation; D016208:Databases, Factual; D004867:Equipment Design; D005260:Female; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D006400:Hematocrit; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008280:Magnetics; D008297:Male; D009716:Numerical Analysis, Computer-Assisted; D012399:Rotation