PMID: 2095141Jan 1, 1990Paper

A comparative study of the shear stress induced in the leakage backflow produced by four types of heart valve prostheses

Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
Y A Haggag

Abstract

The clinical selection of a prosthetic heart valve requires the consideration of many factors. These include the pressure drop across the prosthesis, the amount of leakage backflow when the valve is closed as well as the associated shear stress within this flow for a particular valve design. Major emphasis has been placed upon the documentation of the pressure drop across prosthetic valves. Consideration of the shear stress induced in the leakage backflow associated with prosthetic valves, however, has received less attention. The purpose of this investigation, therefore, is to determine theoretically the extent of this particular shear stress for four types of currently used mechanical prosthetic cardiac valves. All valves have the same tissue annulus diameter of 27 mm. The leakage backflow is relatively small compared to the main forward flow through the orifice. However, it is important from the haemolysis point of view. The effect of the shear stress on the suspected occurrence of haemolysis is analysed by two theoretical approaches: (a) the laminar flow approach, and (b) the entry flow approach, and then compared with the findings of previous investigators dealing with the critical shear stresses which may damage the red b...Continue Reading

References

Feb 1, 1984·Journal of Biomechanical Engineering·H N Sabbah, P D Stein
Feb 1, 1984·Journal of Biomechanical Engineering·T KitamuraH Akashi
Nov 1, 1980·Journal of Biomechanical Engineering·T H ReifM C Huffstutler

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