International Research Fellowship Program: In Vivo Study of Turbulence in the Leakage Jets of Bileaflet Mechanical Heart Valves

Travis, Brandon R, Atlanta GA

Investigators

Abstract

0107348 Travis The International Research Fellow Awards Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will provide twenty-four months of support to Dr. Brandon R. Travis to do research with Dr. Hans Nygaard at the University of Aarhus in Denmark on an in vivo study of turbulence in the leakage jets of bileaflet mechanical heart valves. This project will quantify the velocity field and turbulence of the leakage of prosthetic heart valves after removing sources of error due to estimations in chamber geometry, assumptions of constant viscosity, and failure to remove cyclic variation from calculations of the turbulent stresses. Bileaflet prostheses will be implanted in the mitral position of 90 kg pigs. A high resolution ultrasound transducer positioned on the outer wall of the atrium will be used to measure the turbulent characteristics of the leakage jets immediately proximal to the valve pivots. These measurements will accurately quantify the turbulence created by the leakage of prostheses in vivo. The effects of pivot design, gap width, and exercise on leakage turbulence will be evaluated in the proposed experiments. Observations from these studies may be used to focus the efforts of valve designers on specific aspects of valve geometry, and the protocols developed in the proposed experiments may be used to predict the clinical success of prototype valve designs. The University of Aarhus has all the necessary facilities to carry out this work, as well as a staff experienced in the implantation of heart valve prostheses.