Application of titanium and titanium alloys in cardiovascular restoration materials.Such as nitinol memory alloy.
Examples of the application of titanium and titanium alloys in the human cardiovascular system include artificial heart valves, blood filters, cardiac pacemakers and artificial heart pumps, etc.
Medical titanium plates are used to make medical titanium meshes.
The main advantages are:
① High strength, good chemical stability, and excellent biocompatibility;
② Titanium is non-magnetic, and there are few artifacts in the MRI of the magnetic resonance spectrum;
③ The elasticity and shape recovery function of NiTi memory alloy is very suitable for medical applications.
NiTi alloy is martensitic at low temperature (near zero), and it can easily become a shape that is easy to be introduced into the human body. When the temperature rises to body temperature Reverse phase transition will occur at the time, so as to return to the original shape, and produce a larger restoring force to play a role in orthopedics and support. In recent years, the application of nitinol shape memory alloy in vascular stents has attracted much attention. However, NiTi alloys may dissolve Ni ions under physiological conditions, thereby inducing toxicity and inflammatory reactions. To this end, researchers have conducted a large number of surface modification studies on the alloy. The main methods include surface inert coating, surface oxidation, surface activation and surface grafting of macromolecules, etc. [33] Although they have different footholds, they are all different. It can effectively inhibit the dissolution of Ni ions and improve the corrosion resistance and biocompatibility of NiTi alloys.
According to relevant data [35], the incidence rate of adult rheumatic heart disease in my country is 2.34%～2.72%. According to the total population, there are about 1.9 million adult patients with rheumatic heart disease. There are about 250,000 patients who need artificial heart valve replacement surgery due to severe valve disease, but the actual amount of artificial heart valve is only 25,000. The domestic rate is about 30%. The annual demand for pacemakers is about 400,000. Practical The quantity is 20,000, and the domestic rate is only 1%, while the domestic rate of coronary stent products is relatively high, reaching about 50%.