The Importance of Superelastic Nitinol Wire To Medicine


TThe very first manufactured pieces of superelastic nitinol wire were created in 1991 by the Raychem Corporation of Menlo Park, California. They were made to be included within a laparoscopic set of auto suture endoroticulators, a device that would allow sutures to be done inside the body, deep within tissues by literal remote control, without exposing the entire area to the air. This was only the first surgical breakthrough made with this amazing shape memory material. Since then, the inventions made possible with this memory metal have reached unprecedented levels of success within the application of microsurgical devices.

Want to learn more about superelastic nitinol wire and its use in the medical industry? Contact the experts at Component Supply Company today for a complete breakdown on its applications.

From catheters to super elastic needles, stents and other implantable structures, nitinol has become the material of choice when designing new microsurgical devices and instruments. With the same preferred attributes that stainless steel and titanium had in the past, nitinol wire and tubing has the necessary kink and crush resistance, flexibility, long life without fatigue, and outstanding super elasticity under pressure within the body, without degrading in the temperature range resident in a human body, that less invasive devices require.

Superelastic nitinol wire offers the best compromise between engineered plastics and traditional metals that today's technology can offer, at a reasonable manufacturing cost. It literally offers the highest level of deformity available in shape memory alloys, and still retain its original level of flexibility during use. The alloy is strengthened during processing through a combination of cold working, aging and annealing, at the same time making it unusable in most commercial applications because the processing also grants it a very narrow window of temperature tolerance before losing that elasticity. Thankfully, the temperature range found inside most mammals makes it the perfect tool for hundreds of uses, despite that flaw.

The best illustration of its inherent flexibility and durability as a memory wire within a medical device is its use in an atrial septal-defect occlusion device recently developed to seal holes in the atrial wall from the inside, without major surgery. The device is comprised of five nitinol wire loops that support webs of microporous polyurethane, like small umbrellas. The umbrellas are folded into two catheters, inserted and positioned to either side of the detected hole. A guide wire passes through the hole to position the umbrellas correctly, and then the umbrellas are passed through and joined together using a special torquing catheter. Once connected, they form a seal over the hole that will still allow pressure and blood to pass through it, stabilizing the wall once more.

Summary

With the advent of superelastic nitinol wire and its use in microsurgical devices, an entire new world has been opened up in medical technology. Being able to perform major surgery in a less invasive manner will save countless lives and minimize risk for the patient.