Development of a low-priced artificial heart, valve with high valvular functions

第一年，从价格、机械强度、可加工性和加工后表面状况等方面选择了超硬铝材作为构建人工心脏瓣膜的材料。在计算机模拟和流动可视化研究中，在商用阀门的阀瓣远端和阀环周围观察到了滞止和涡流现象，开发的中心流动型拱形襟翼双叶阀获得了相对稳定的流态。采用溅射的方法在超硬铝皮瓣上沉积氧化铝，以提高其耐久性和血液相容性。反应溅射沉积的薄膜比常规溅射沉积的薄膜更光滑、更坚固。通过插入功能梯度材料，薄膜的耐久性和附着力提高了一倍。第二年，通过静态和动态流动试验，确定了基于流体动力学的阀门设计。襟翼由枢轴支撑并在关闭位置倾斜。该阀具有相对较大的小孔，以获得足够的二次流量。接触性凝血因子和血小板的激活。对溅射沉积氧化铝表面的附着力进行了检测。实验表明，氧化铝具有与生物材料一样良好的血液相容性。在过去的一年里，根据静态和动态流动测试以及流动可视化研究，确定了瓣的曲率、点滴位置和瓣的张开角度。最佳曲度为9%，枢轴位置为70%，张开角度为67度。阀环由不锈钢加工而成，表面镀有TiN。阀环也可以用钛加工而成。我们还开发了一种加速耐久测试系统，其速度是其他系统的三倍，同时也具有较低的水击压力。

In the first year ultra-duralumin was selected as a material to construct an artificial heart valve from the standpoints of price, mechanical strength, machanibility, and surface condition after machining. Stagnation and vortexes were observed in the regions distal to valve flaps and also around valve ring of commercially available valves in both computer simulation and flow visualization studies, Relatively stable flow pattern was obtained in the developed central flow-type bileaflet valve with arched flaps. Alumina was deposited on the ultra-duralumin flaps by sputtering to immprove durability and blood compatibility. Reactive sputtering deposited smoother and stronger membrane than conventional sputtering. By interposing functionally gradient material durability and adhesion of the film increased twice.In the second year valve design was determined based on fluid dynamics in both static and dynamic flow tests. The flaps are supported by pivots and inclined at the closed position. The valve has relatively large minor orifice to obtain enough secondary flow. Activation of contact coagulation factor and also platelet. Adhesion on the sputter-deposited alumina were examined. The experiments disclosed that the alumina has as good blood ompatibility as biomaterials.In the last year curvature of the flap, position of the pivol, and opening angle of the flap were determined based on static and dynamic flow tests and also flow visualization studies. The optimun curvature was 9%, pivot position 70%, and opening angle 67 degrees. The valve ring was machined from stainless steel and the surface was coated by TIN. The valve ring can also be machined from titanium. We also developed an accelerated endurance test system with the speed three times higher than other systems and also with lower water hammer pressure.