Nitinol spool: an innovative force in the field of medical devices - an in-depth analysis using cardiac stents as an example

Nickel-titanium alloy, also known as Nitinol, is a binary alloy composed of nickel (Ni) and titanium (Ti). It has quickly become a research topic in the field of materials science since it was discovered to have a shape memory effect in the 1960s. Hotspot. Shape memory effect refers to the ability of a material to return to its original shape after deformation by heating, cooling, or removing stress. This characteristic enables nickel-titanium alloys to undergo significant reversible deformation when subjected to external forces and return to their original shape under specific conditions, thus giving it unique engineering application value.

In nickel-titanium alloys, the realization of this shape memory effect relies on its unique microstructure-the reversible transformation between the martensite phase and the austenite phase. At low temperatures, nickel-titanium alloys present a hard and brittle martensite phase; when the temperature rises to a certain critical value, the martensite phase transforms into a soft and tough austenite phase, accompanied by shape recovery. . This process not only gives the nickel-titanium alloy a unique shape memory ability, but also makes it have excellent superelasticity, that is, it can undergo a wide range of elastic deformation under stress without permanent deformation.

As an important tool for cardiac interventional treatment, the main function of cardiac stents is to support narrowed or occluded coronary arteries and restore normal blood flow, thereby relieving angina pectoris and preventing serious cardiovascular diseases such as myocardial infarction. Although traditional metal stents, such as stainless steel stents, can effectively support blood vessels, they have potential risks such as vascular restenosis and inflammatory reactions. The introduction of nickel-titanium alloy spool heart stents has solved these problems to a certain extent.

The nickel-titanium alloy heart stent, using its shape memory effect and superelasticity, can be easily sent into the body through a catheter after being compressed. Once it reaches the target location, through body temperature or external stimulation, the stent can quickly expand to the preset shape and fit tightly. Combined with blood vessel wall. This process not only reduces surgical trauma, but also ensures good contact between the stent and the vessel wall, reducing the risk of stent migration.

The material of the nickel-titanium alloy heart stent makes it have excellent biocompatibility and corrosion resistance, reducing the risk of foreign body reaction and thrombosis. In addition, due to its superelastic properties, stents are able to adapt to long-term physiological changes in blood vessels, such as contraction and expansion of blood vessel walls, thereby reducing the incidence of vessel restenosis.

Specific application of shape memory effect in cardiac stents
Personalized design: Nitinol heart stents can be personalized according to the patient's vascular anatomy and lesion characteristics, ensuring perfect fit between the stent and the blood vessel wall and reducing damage to healthy blood vessels.
Intelligent response: Utilizing the shape memory effect of nickel-titanium alloy, the stent can automatically adjust its shape according to changes in body temperature and blood flow velocity, maintaining continuous contact with the blood vessel wall, effectively preventing stent displacement and vessel restenosis.
Biocompatibility: The excellent biocompatibility of nickel-titanium alloy reduces the inflammatory reaction and thrombosis after stent implantation, and improves the quality of life and prognosis of patients.
Degradability: With the deepening of research, some nickel-titanium alloy heart stents also have a certain degree of degradability and can gradually degrade after completing the support task, avoiding the problem of long-term foreign bodies and providing future cardiac interventional treatments. New directions.