Abstract:
:This study was aimed at developing a physical model, supported by experimental observations, to describe the formation and growth of microbubbles seen in patients with mitral mechanical heart valves (MHV). This phenomenon, often referred to as high intensity transient signals (HITS), appears as bright, intense, high-velocity and persistent echoes detected by Doppler ultrasonography at the instant of closure. The long-term clinical implications of HITS has yet to be determined. However, there are reports of a certain degree of neurological disorder in patients with mitral MHV. The numerical analysis has shown the existence of a twofold process (1) nucleation and (2) microbubble growth as a result of cavitation. While mild growth of nuclei is governed by diffusion, explosive growth of microbubbles is controlled by pressure drop on the atrial side of mitral MHV. It was demonstrated that there exist limits on both microbubble size and regurgitant velocity, above which microbubbles grow explosively, and below which growth is almost nonexistent. Therefore, prevention of excessive pressure drops induced by high closing velocities related to the dynamics of closure of mitral MHV may offer design changes in the future generations of mechanical valves.
journal_name
Ann Biomed Engjournal_title
Annals of biomedical engineeringauthors
Rambod E,Beizaie M,Shusser M,Milo S,Gharib Mdoi
10.1114/1.231subject
Has Abstractpub_date
1999-11-01 00:00:00pages
774-92issue
6eissn
0090-6964issn
1573-9686journal_volume
27pub_type
杂志文章abstract::Rapid screening of biomarkers, with high specificity and accuracy, is critical for many point-of-care diagnostics. Microfluidics, the use of microscale channels to manipulate small liquid samples and carry reactions in parallel, offers tremendous opportunities to address fundamental questions in biology and provide a ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章,评审
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journal_title:Annals of biomedical engineering
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