Numerical Study Of Interventional Spiral Vascular Robot

Cardiovascular disease is a serious of diseases affecting human health. There aremany treatment method of Cardiovascular disease. The vascular robot is one of theimportant treatment, which swim accurately, flexibly running. Because of differentswim methods, and staying in different position, the interaction between robot andvascular external environment make the robot using effect affected. Therefore, it isvery necessary to study the flow characteristics of pulsation of blood, when thevascular robot swim in the blood. In this paper, based on the result of numericalsimulation, such as fluid-solid coupling and two phase of blood, make a deep study onthe homodynamic characteristics of the vascular robot into the vessel under dynamicboundary condition. This thesis research mainly in three aspects:In order to make the robot to realize the rapid push and stable rotary motion inblood, numerical simulation is carried out to optimize the thread parameters onvascular robot. The results show that：when the thread number is6; the screw angle is45°; β value is0.3, the axial force of the optimized model is4.69times than thatbefore, and the fluid resistance moment is only0.18times than it.Combined with the dynamic simulation method and fluid-structure couplingmethod, comparing the difference hemodynamic parameters between elastic vascularmodel and rigid vascular model. The results show that: in a heartbeat cycle, maximumdeformation of elastic vessels is the entrance of the vessel diameter2.4%; themaximum wall shear is7.95Pa; the range size of the pressure and the velocity issmaller than the solid model, but the velocity streamline is more disorder.For the real blood vessel build by3D medical imaging technology, is smaller insize and more complex. If the blood is treated as a single Newton fluid, the result ofnumerical simulation will be a big error. At the same time, the robot can be affectedby the mass particle, when it make rotary motion at high speed. Therefore, it isnecessary to consider the influence of red blood cell. In a other word, the blood isregarded as the blood plasma and red blood cells. Based on this hypothesis, thecharacteristic of the two-phase blood flow is studied using the Eulerian multiphase flow model, when the vascular robot is involved in the typical blood vessel, such asthe hardening vessel, bifurcation vessel, cured vessel. The results show that:Comparing the three different vessels, the wall sheer stress is maximum, and thevolume concentration of red blood cells is minimum, when the vascular robot swimnear the bent position.These studies provide valuable references for the detection of blood parametersand the diagnosis of vascular diseases, when the vascular robot swim in the humanbody in future.