TY - JOUR
T1 - Mechanisms of cavitation and the formation of stable bubbles on the Björk-Shiley Monostrut prosthetic heart valve
AU - Bachmann, Christopher
AU - Kini, Vinayak
AU - Deutsch, Steven
AU - Fontaine, Arnold A.
AU - Tarbell, John M.
PY - 2002/1
Y1 - 2002/1
N2 - Background and aims of the study: Transcranial Doppler studies performed on patients with the Björk-Shiley Monostrut mechanical heart valve have detected signals typical of gaseous emboli. Methods: In this study, a high-speed digital imaging system was used to examine the closure event of the Björk-Shiley Monostrut valve in vitro. Results: Observations support the hypothesis that cavitation occurs before the formation of stable gas bubbles. Bubble cavitation occurs at the instant of valve closure and lasts on the order of 0.3 ms. The rebounding motion of the occluder initiates the development of a vortex which induces vortex cavitation. Vortex cavitation begins ∼0.5 ms after impact of the occluder and the valve housing (∼0.2 ms after bubble cavitation has subsided), and lasts for ∼1 ms. The formation of stable bubbles occurs later, along the center of the vortex that persists throughout much of the first rebound. Conclusion: It is hypothesized that the low-pressure region at the center of the vortex contributes to the formation of stable bubbles by collecting expanded nuclei that arise from both bubble and vortex cavitation, and providing a low-pressure environment in which the nuclei combine and continue to grow.
AB - Background and aims of the study: Transcranial Doppler studies performed on patients with the Björk-Shiley Monostrut mechanical heart valve have detected signals typical of gaseous emboli. Methods: In this study, a high-speed digital imaging system was used to examine the closure event of the Björk-Shiley Monostrut valve in vitro. Results: Observations support the hypothesis that cavitation occurs before the formation of stable gas bubbles. Bubble cavitation occurs at the instant of valve closure and lasts on the order of 0.3 ms. The rebounding motion of the occluder initiates the development of a vortex which induces vortex cavitation. Vortex cavitation begins ∼0.5 ms after impact of the occluder and the valve housing (∼0.2 ms after bubble cavitation has subsided), and lasts for ∼1 ms. The formation of stable bubbles occurs later, along the center of the vortex that persists throughout much of the first rebound. Conclusion: It is hypothesized that the low-pressure region at the center of the vortex contributes to the formation of stable bubbles by collecting expanded nuclei that arise from both bubble and vortex cavitation, and providing a low-pressure environment in which the nuclei combine and continue to grow.
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M3 - Article
C2 - 11843495
AN - SCOPUS:0036357996
SN - 0966-8519
VL - 11
SP - 105
EP - 113
JO - Journal of Heart Valve Disease
JF - Journal of Heart Valve Disease
IS - 1
ER -