Document Detail


Optimizing the response from a passively controlled biventricular assist device.
MedLine Citation:
PMID:  20633154     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Recent studies into rotary biventricular support have indicated that inadequate left/right flow balancing may lead to vascular congestion and/or ventricular suckdown. The implementation of a passive controller that automatically adjusts left/right flow during total and partial cardiac support would improve physiological interaction. This has encouraged the development of a biventricular assist device (BiVAD) prototype that achieves passive control of the two rotary pumps' hydraulic output by way of a nonrotating double pressure plate configuration, the hub, suspended between the ventricular assist device (VAD) impellers. Fluctuations in either the VAD's inlet or outlet pressure will cause the hub to translate, and in doing so, affect each pump's hydraulic outputs. In order to achieve partial support, the floating assembly needed to respond to pathologic blood pressure signals while being insensitive to residual ventricular function. An incorporated mechanical spring-mass-damper assembly affects the passive response to optimize the dynamic interaction between the prototype and the supported cardiovascular system. It was found that increasing the damping from a medium to a high level was effective in filtering out the higher frequency ventricular pressure signals, reducing a modified amplitude ratio by up to 72%. A spring response was also identified as being inherent in the passive response and was characterized as being highly nonlinear at the extremes of the floating assembly's translation range. The results from this study introduce a new means of BiVAD control as well as the characterization of a fully passive mechanical physiological controller.
Authors:
Nicholas Richard Gaddum; Daniel L Timms; Mark John Pearcy
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Artificial organs     Volume:  34     ISSN:  1525-1594     ISO Abbreviation:  Artif Organs     Publication Date:  2010 May 
Date Detail:
Created Date:  2010-07-16     Completed Date:  2010-10-18     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7802778     Medline TA:  Artif Organs     Country:  United States    
Other Details:
Languages:  eng     Pagination:  393-401     Citation Subset:  IM    
Affiliation:
School of Engineering Systems and Medical Device Domain, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane, QLD 4059, Australia. nickgaddum@gmail.com
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MeSH Terms
Descriptor/Qualifier:
Computer Simulation
Equipment Design
Heart-Assist Devices*
Humans
Models, Cardiovascular

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


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