Document Detail


Effect of the sinus of valsalva on the closing motion of bileaflet prosthetic heart valves.
MedLine Citation:
PMID:  10816206     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Conventional bileaflet prosthetic mechanical heart valves close passively with backflow. Naturally, the valve has problems associated with closure, such as backflow, water hammer effect, and fracture of the leaflet. On the other hand, in the case of the natural aortic valve, the vortex flow in the sinus of Valsalva pushes the leaflet to close, and the valve starts the closing motion earlier than the prosthetic valve as the forward flow decelerates. This closing mechanism is thought to decrease backflow at valve closure. In this study, we propose a new bileaflet mechanical valve resembling a drawbridge in shape, and the prototype valve was designed so that the leaflet closes with the help of the vortex flow in the sinus. The test valve was made of aluminum alloy, and its closing motion was compared to that of the CarboMedics (CM) valve. Both valves were driven by a computer controlled hydraulic mock circulator and were photographed at 648 frames/s by a high speed charge-coupled device (CCD) camera. Each frame of the valve motion image was analyzed with a personal computer, and the opening angles were measured. The flow rate was set as 5.0 L/min. The system was pulsed with 70 bpm, and the systolic/diastolic ratio was 0.3. Glycerin water was used as the circulation fluid at room temperature, and polystyrene particles were used to visualize the streamline. The model of the sinus of Valsalva was made of transparent silicone rubber. As a result, high speed video analysis showed that the test valve started the closing motion 41 ms earlier than the CM valve, and streamline analysis showed that the test valve had a closing mechanism similar to the natural one with the effect of vortex flow. The structure of the test valve was thought to be effective for soft closure and could solve problems associated with closure.
Authors:
Y Ohta; Y Kikuta; T Shimooka; Y Mitamura; T Yuhta; T Dohi
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Artificial organs     Volume:  24     ISSN:  0160-564X     ISO Abbreviation:  Artif Organs     Publication Date:  2000 Apr 
Date Detail:
Created Date:  2000-06-13     Completed Date:  2000-06-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7802778     Medline TA:  Artif Organs     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  309-12     Citation Subset:  IM    
Affiliation:
Department of Mechanical Engineering, Toyo University, Kawagoe, Japan. yuji@eng.toyo.ac.jp
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MeSH Terms
Descriptor/Qualifier:
Alloys
Aluminum
Aortic Valve*
Blood Pressure
Heart Rate
Heart Valve Prosthesis*
Hemorheology
Humans
Image Processing, Computer-Assisted
Models, Anatomic
Movement
Prosthesis Design*
Prosthesis Failure
Regional Blood Flow
Silicone Elastomers
Sinus of Valsalva / physiology*
Video Recording
Chemical
Reg. No./Substance:
0/Alloys; 0/Silicone Elastomers; 7429-90-5/Aluminum

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


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