Hemodynamic Characteristics Device Test Development In Vitro

Blood is a kind of complex fluid, Blood flow in the body is a complex process, the intravascular hemodynamic characteristics has important practical significance, such as through research is vascular blood flow to a long period to judge whether the vascular anomalies. For a long time, for the test of hemodynamic characteristics in the human body has always been a research difficulties, in the human body directly testing intravascular hemodynamic parameters, program flow not only complex, and the experimental environment and condition is harsh and difficult to achieve. Through building system of extracorporeal circulation to simulate the blood flow can effectively within the vascular hemodynamic characteristics test. In vitro hemodynamic characteristics testing system has high maneuverability, high controllability, etc. It is widely used in modern biomedical research and clinical medical examination, etc.This paper developed a set of in vitro hemodynamic characteristics test equipment, including in vitro blood circulatory system and the dynamic testing system, we test and analyze the simulation of the endovascular hemodynamic characteristics, the rule of the test results with the real human body blood flow dynamics is consistent, verify the feasibility of in vitro hemodynamic characteristics test device.First of all, according to the three components elastic Chambers model constructed blood circulation system in vitro, powered by peristaltic pump device, 0.9% NaCl solution to simulate blood, silicone hose to simulate the transmission system of blood, the suction filter bottle to simulate blood storage room, set up the blood flow device in vitro, for the entire system to provide the continuous pulse simulated blood flow.Secondly, inlet pressure characteristic testing system is designed, with diffusion silicon pressure transmitter, high speed data acquisition card, computer, regulated power supply as the foundation of the system hardware;Data acquisition interface, the Visual C++ platform to collect and save the data; Based on the system, the error analysis show that the system reliability is higher.Again, a particle image velocimetry system, with CMOS camera, microscopic lens, depending on the light, computer hardware;Using "refer to white" illumination compensation algorithm to improve the image quality and precise calibration the pixels and the length of the relationship;Feature extraction is proposed based on color space conversion of particles and particle tracking velocimetry based on SIFT algorithm, by constructing scale space, locate feature points and feature points is generated descriptor finally calculate slope distance of the particle image for matching of the particles, the average speed of calculating the average speed of particles, the characterization of simulate the average speed of blood flow.Design the particle velocity measuring system based on Visual C++, the particle image for mapping to the same coordinate system, the test simulation of blood flow velocity distribution.Finally, analysis the hard glass material preparation of straight?curved?and Y type transparent rigid simulation vascular hemodynamic.Through dyeing line flow field display method to simulate the flow field in the blood vessels made a general understanding;Set the peristaltic pump speed in 60~120r/min(peristaltic pump speed characterization of cardiac cycle 1~0.5s), test respectively three simulated blood vessels of inlet pressure, average velocity and velocity distribution, the analysis of the effect of vascular shape on the flow characteristics.In this paper, a preliminary implementation of in vitro blood flow system preliminary simulation, hemodynamic characteristics test system is developed, the law of the test results accord with human body blood flow, at the same time, the results of numerical simulation was verified.