| At present,patients with end-stage heart failure can be treated by implanting a blood pump when medicine fails.However,it is easy to cause blood compatibility problems when works.When studying the blood compatibility of the blood pump through experiments,there are problems such as inconvenience of blood cell extraction,complicated experiment and disturbance of external factors.Therefore,this project used orthogonal experiment to study the influence of processing texture on the surface morphology of blood pump,and to further study the influence of different surface morphology on the blood compatibility of blood pump,thus a theoretical basic can be provided for the improving of the process quality and clinical application of blood pump.First of all,the working principle and the structure of centrifugal blood pump were introduced,and a blood pump simulation model was established in Solid Works,the structure of blood pump which causes blood compatibility problems and the forming principle of processing texture were also elaborated.Then,the tool coordinate system in the process of machining was analyzed,and the surface topography of Tc4 titanium alloy used in heart pump was simulated according to the above tool coordinate system.Secondly,the integrity analysis of the inner surface of the centrifugal artificial blood pump hearth shell made of Tc4 titanium alloy was carried out.The orthogonal experiment planning of the surface processing texture stroke was carried out,and then the experiment was conducted after determining the path of the surface treatment.Through the design of the orthogonal experiment,the influence of different cutting dosage on the surface processing integrity was analyzed and with the further single factor experiments,the comparative experiments of the influence of different parameters on heart pump morphology such as variable cutting speed,cutting depth,cutting width,feed engagement were conducted.And then,white light interferometer were used to extract the surface morphology,thus,the processing parameters could be optimized with genetic algorithms.Thirdly,the influence of shear stress and exposure time on blood damage was analyzed.In order to simulate the process of blood flow and calculate the damage of blood pump to blood,the standard turbulence model and blood damage prediction model were used.After that,the blood pump flow field and the degree of destruction of blood cells were calculated according to the Lagrangian method,and the influence of surface morphology on the adhesion of blood cells was analyzed with the building of model of the influence of surface morphology on the adhesion of blood cells.Finally,a blood compatibility experiment platform for the inner surface morphology of heart pump was set up,and the destruction of blood cells and thrombosis of different surface texture obtained by orthogonal experiments were measured and analyzed under the condition of running or resting blood pump.And the influence of surface morphology on blood compatibility were further analyzed. |
PDF Full Text Request