Study on Fluid Dynamic Characteristics of Turbulent Blood Flow

湍流血流的流体动力学特性研究

基本信息

批准号：
11650199
负责人：
TSUKIYA Tomonori
金额：
$ 1.41万
依托单位：
Research Institute of National Cardiovascular Center
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

The pressure - flow rate relationship in the ventricular assist system consisting of an artificial heart is helpful in order to diagnose and detect abnormal condition of the system, or to develop indirect measurement system which saves sensors for pressure and flow rate of the device being used. For example, we have developed the indirect flow rate measurement system using the power consumption of the driving motor of the centrifugal blood pump. This relationship, however, is subject to the physical properties of blood as well as the configuration of the system. The physical properties of flowing blood, or rheology of blood, is essential for such aims, but reports on physical properties of flowing blood under turbulent state, which is often observed in the mechanical assisting devices like artificial hearts, has hardly been investigated. The pressure drop across the circular pipe of turbulent flow was measured and compared between goat blood and a Newtonian fluid. Goat blood demonstrat … More ed slight decrease in the pressure drop than the Newtonian fluid, and the magnitude of the decrease in pressure drop was independent of blood cell concentration. The indirect measurement of flow rate of a centrifugal blood pump using motor power consumption was attempted, in which the effect of viscosity change on the accuracy was investigated. The centrifugal blood pump developed in our research institute was installed between the left apex and the descending aorta making a left heart bypass. The flow rate measured by this method has demonstrated sufficient accuracy for practical use when the viscosity is known. The extent of errors fluctuated with the change of hematocrit after in the course of time after surgical operation. The errors could be corrected by measuring the viscosity of the blood to the practically acceptable range by calibration data obtained with Newtonian fluids. The difference in pressure drop in turbulence due to Non-Newtonian properties, which was observed in the turbulent pipe flow, was found to have negligible effects in this measurement method of flow rate for the practical use. Less

由人造心脏组成的心室辅助系统中的压力 - 流速关系有助于诊断和检测系统的异常状况，或开发间接测量系统，从而为所使用的设备的压力和流量节省了传感器。例如，我们使用离心血泵的驱动电动机的功耗开发了间接流量测量系统。但是，这种关系符合血液的物理特性以及系统的配置。流动血液的物理特性或血液流变性对于此类目的至关重要，但是在湍流状态下流动血液的物理特性的报道几乎没有被研究在湍流状态下，这在人工心等机械辅助设备中经常观察到。测量了湍流圆形管道的压降，并在山羊血和牛顿流体之间进行了比较。山羊血液表明…与牛顿液相比，压降的压力下降略有下降，压降降低的幅度与血细胞浓度无关。尝试使用运动功率消耗对离心血泵的流量进行间接测量，其中研究了粘度变化对准确性的影响。在我们的研究所中开发的离心血泵是在左端和降主动脉之间安装的，这使左心旁路。通过这种方法测量的流速已表明在已知粘度时实际使用足够精度。手术手术后的时间后，随着血细胞比容的变化，误差的程度波动。可以通过用牛顿流体获得的校准数据来测量血液对实际上可接受的范围的粘度来纠正这些误差。发现在湍流流动中观察到的非牛顿特性引起的湍流压力下降的差异在这种实际使用的流量测量方法中具有可忽略不计的作用。较少的