Document Detail

In vitro study of flow regulation for pulmonary insufficiency.
MedLine Citation:
PMID:  17408334     Owner:  NLM     Status:  MEDLINE    
Given the tolerance of the right heart circulation to mild regurgitation and gradient, we study the potential of using motionless devices to regulate the pulmonary circulation. In addition, we document the flow performance of two mechanical valves. A motionless diode, a nozzle, a mechanical bileaflet valve, and a tilting disk valve were tested in a pulmonary mock circulatory system over the normal human range of pulmonary vascular resistance (PVR). For the mechanical valves, regurgitant fractions (RFs) and transvalvular pressure gradients were found to be weak functions of PVR. On the low end of normal PVR, the bileaflet and tilting disk valves fluttered and would not fully close. Despite this anomaly, the regurgitant fraction of either valve did not change significantly. The values for RF and transvalvular gradient measured varied from 4 to 7% and 4 to 7 mm Hg, respectively, at 5 lpm for all tests. The diode valve was able to regulate flow with mild regurgitant fraction and trivial gradient but with values higher than either mechanical valve tested. Regurgitant fraction ranged from 2 to 17% in tests extending from PVR values of 1 to 4.5 mm Hg/lpm at 5 lpm and with concomitant increases in gradient up to 17 mm Hg. The regurgitant fraction for the nozzle increased from 2 to 23% over the range of PVR with gradients increasing to 18 mm Hg. The significant findings were: (1) the mechanical valves controlled regurgitation at normal physiological cardiac output and PVR even though they failed to close at some normal values of PVR and showed leaflet flutter; and (2) it may be possible to regulate the pulmonary circulation to tolerable levels using a motionless pulmonary valve device.
T A Camp; K C Stewart; R S Figliola; T McQuinn
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of biomechanical engineering     Volume:  129     ISSN:  0148-0731     ISO Abbreviation:  J Biomech Eng     Publication Date:  2007 Apr 
Date Detail:
Created Date:  2007-04-05     Completed Date:  2007-06-26     Revised Date:  2013-06-06    
Medline Journal Info:
Nlm Unique ID:  7909584     Medline TA:  J Biomech Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  284-8     Citation Subset:  IM    
Departments of Mechanical Engineering and Bioengineering, Clemson University, Clemson, SC 29631, USA.
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MeSH Terms
Blood Flow Velocity
Blood Pressure
Heart Valve Prosthesis*
Models, Cardiovascular*
Prosthesis Design
Pulmonary Valve / physiopathology*
Pulmonary Valve Insufficiency / physiopathology*
Grant Support

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