Examples of applications of medical titanium rods in human cardiovascular are artificial heart valves, blood filters, cardiac pacemakers and artificial heart pumps.
The main advantages are:
① High strength, good chemical stability and excellent biocompatibility;
② Titanium is non-magnetic and rarely produces artifacts in the magnetic resonance spectrum MRI;
③ The elasticity and shape recovery function of NiTi memory alloy is very suitable for medical applications. NiTi alloy is in a martensite state at low temperatures (near zero degrees), and it is easy to change into a shape that is easy to introduce into the human body. When the temperature rises to body temperature There will be a reverse phase change, which will restore the original set shape, and generate a large restoring force for orthopedics and support. In recent years, the application of NiTi shape memory alloys in vascular stents has attracted much attention. However, NiTi alloy may dissolve Ni ions under physiological conditions, thereby inducing toxicity and inflammatory reactions. To this end, researchers conducted a large number of surface modification studies on the alloy, the main methods are surface inert coating, surface oxidation, surface activation, and surface grafting of macromolecules. Although the standpoints are different, they can effectively inhibit the elution of Ni ions and improve the corrosion resistance and biocompatibility of NiTi alloys. According to relevant information, the incidence of adult rheumatic heart disease in my country is 2.34% to 2.72%, which is estimated to be about 1.9 million adult rheumatic heart disease patients based on the total population. There are about 250,000 patients requiring artificial heart valve replacement surgery due to severe valve disease, but the actual artificial heart valve is only 25,000, and the domestic rate is about 30%. The annual demand for pacemakers is about 400,000, and the practical amount is The domestic production rate of 20,000 units is only 1%, while the domestic production rate of coronary stent products is relatively high, reaching about 50%.