Document Detail


Particle-image velocimetry study of a pediatric ventricular assist device.
MedLine Citation:
PMID:  20590282     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Particle-image velocimetry (PIV) was used to visualize the flow within an optically transparent pediatric ventricular assist device (PVAD) under development in our laboratory. The device studied is a diaphragm type pulsatile pump with an ejection volume of 30 ml per beating cycle intended for temporary cardiac assistance as a bridge to transplantation or recovery in children. Of particular interest was the identification of flow patterns, including regions of stagnation and/or strong turbulence that often promote thrombus formation and hemolysis, which can degrade the usefulness of such devices. For this purpose, phase-locked PIV measurements were performed in planes parallel to the diaphragm that drives the flow in the device. The test fluid was seeded with 10 microm polystyrene spheres, and the motion of these particles was used to determine the instantaneous flow velocity distribution in the illumination plane. These measurements revealed that flow velocities up to 1.0 m/s can occur within the PVAD. Phase-averaged velocity fields revealed the fixed vortices that drive the bulk flow within the device, though significant cycle-to-cycle variability was also quite apparent in the instantaneous velocity distributions, most notably during the filling phase. This cycle-to-cycle variability can generate strong turbulence that may contribute to greater hemolysis. Stagnation regions have also been observed between the input and output branches of the prototype, which can increase the likelihood of thrombus formation.
Authors:
E Ferrara; M Muramatsu; K T Christensen; I A Cestari
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of biomechanical engineering     Volume:  132     ISSN:  1528-8951     ISO Abbreviation:  J Biomech Eng     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-07-01     Completed Date:  2010-10-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7909584     Medline TA:  J Biomech Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  071004     Citation Subset:  IM    
Affiliation:
Optics Group, Physics Institute, University of São Paulo, São Paulo, SP Brazil. eferrara@if.usp.br
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MeSH Terms
Descriptor/Qualifier:
Child
Heart Ventricles
Heart-Assist Devices*
Hemolysis
Humans
Rheology / instrumentation*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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