Turbulence Characteristics Downstream of Bileafiet Aortic Valve Prostheses  

Oleh:

Liu, J. S. ; Lu, P. C. ; Chu, S. H.

Jenis: Article from Bulletin/Magazine
Dalam koleksi: Journal of Biomechanical Engineering vol. 122 no. 2 (2000), page 118-124.
Topik: characteristic; turbulence; characteristics; downstream; bileaflet; aortic valve;

Ketersediaan

Perpustakaan Pusat (Semanggi) Nomor Panggil: JJ52.1 Non-tandon: 1 (dapat dipinjam: 0) Tandon: tidak ada

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Isi artikel

This study was focused on a series of in vitro tests on the turbulent flow characteristics of three bileaflet aortic valves : St. Jude Medical (SJM), CarboMedics (CM), and Edwards Tekna (modified Duromedics, DM). The flow fields of the valves were measured in a pulsatile flow model with a laser - Doppler anemometer (LDA) at the aortic sinus area downstream of the valves. The heart rate was set at 70 beats per minute, the cardiac output was maintained at 5 liters per minute, and the aortic pressure wave forms were kept within the physiological range. Cycle - resolved analysis was applied to obtain turbulence data, including mean velocity, Reynolds stresses, autocorrelation coefficients, energy spectral density functions, and turbulence scales. The Reynolds shear stresses of all three valves induced only minor damage to red blood cells, but directly damaged the platelets, increasing the possibility of thrombosis. The smallest turbulence length scale, which offers a more reliable estimate of the effects of turbulence on blood cell damage, was three times the size of red blood cells and five times the size of platelets. This suggests that there is more direct interaction with the blood cells, thus causing more damage.

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