چكيده به لاتين
Abstract:
The use of cardiac assist devices is one of the common methods in treating patients who suffer from heart failure. Among all the various types of these devices, counterpulsation based extra-aortic device is preferred due to its advantages. The extra-aortic balloon, pumps the blood into circulatory system. In this paper, the balloon and the aorta are modeled during the usage of the assist device. The blood flow in the aorta and von Mises stress are investigated by fluid-structure interaction analysis. Three materials and seven thicknesses are considered for the balloon in one layered and three layered aorta models and the influences of each of these states on the mentioned parameters have been studied. By 1.5% incresase in the balloon’s thickness, von Mises stress on the balloon decreases by 28.35 to 38.99%. By investigating von Mises stress distribution across the aorta’s wall and the balloon, it was found that a disconnection happens at the location of material shift (different layers in three-layered aorta and the common boundary of the aorta and the balloon) which could be a decline or an increase according to material’s Young’s Modulus. Balloon’s inflation augments the blood velocity and increases von Mises stress. Increasing the balloon’s thickness and its Young’s Modulus, will decrease maximum von Mises stress at the time of maximum flow entering the aorta’s section and the time of balloon’s inflation but it will also decrease blood’s velocity.
Keywords: Exrtra-Aortic Balloon, Fluid-Structure Interaction Analysis, Heart Failure
