Laser cutting of stents and other medical devices

Abstract

A desired pattern may be cut into a stent preform by impinging a laser beam onto the stent preform. The laser beam is formed using a laser system comprising a resonator cavity for resonating laser radiation, a gain medium contained in the resonator cavity, a pump for periodically pumping the gain medium and an electro-optical modulator in communication with the resonator cavity. The laser system produces a radiation pulse for each pump period. Each radiation pulse is conditioned by suppressing at least a portion of the pulse. The pulse may also be modulated with an electro-optical modulator to produce a pulse train of ordered pulses of radiation. Each pulse train is output from the optical cavity as an output laser beam which is directed at the stent preform to cut a desired pattern in the stent preform.

Description

STATEMENT OF RELATED APPLICATIONS [0001] This application is a continuation of, and claims the benefit of priority to co-pending U.S. patent application Ser. No. 10 / 436,873, filed May 12, 2003 and entitled “Laser Cutting Of Stents And Other Medical Devices,” which is a continuation-in-part of U.S. application Ser. No. 09 / 681,192 filed Feb. 15, 2001. Both of the above-referenced prior applications are incorporated herein in their entireties by reference.BACKGROUND OF THE INVENTION [0002] A stent is a radially expandable endoprosthesis which is adapted to be implanted in a body lumen. Stents are typically used in the treatment of atherosclerotic stenosis in blood vessels and the like to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. They have also been implanted in urinary tracts and bile ducts and other bodily lumen. They may be self-expanding or expanded by an internal radial force, such as when mounted on a balloon. [0003] Delivery an...

AI Technical Summary

Benefits of technology

The present invention relates to a method of processing a stent preform by using a laser system to cut a desired pattern. The laser system produces a laser beam that is directed onto the stent preform and impinged onto it to create the desired pattern. The laser beam is generated by a resonator cavity that contains a gain medium and a pump for periodically pumping it. The laser system produces a radiation pulse for each pump period, which is then conditioned to produce a pulse train with a specific pattern. The conditioned pulse train is then directed onto the stent preform to create the desired pattern. The invention also includes an image processing head for use with a laser. The technical effects of the invention include improved precision and accuracy in stent patterning, reduced labor and production costs, and improved quality of stent manufacturing.

Problems solved by technology

The initial part of the pulse, labeled as A and the tail end of the pulse, labeled as C, produce heating and melting of materials such as metals causing recrystallization of the metal and microcracks and is not as effective in cutting as the more intense portion of the beam.

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