BACKGROUND OF THE INVENTION

The present invention generally relates to the field of guidewires. More particularly, the present invention relates to various embodiments of guidewires that are useful for advancing intraluminal devices such as stent delivery catheters, balloon dilatation catheters, atherectomy catheters, and the like, through a patient's body, such as through a patient's vasculature. This invention is also useful for electrophysiology catheters.

SUMMARY OF THE OF INVENTION

The present invention relates to a guidewire that is specifically designed for use in various minimally invasive vascular applications. Its foundation is a composite drawn filled tube that is constructed of a stainless steel sheath jacketing a nitinol core wire. The distal portion of the drawn filled tube is machined to remove the stainless steel sheath and expose the nitinol core wire. The distal end of the nitinol wire is the end which interacts with the patient and must be atraumatic, kink resistant, and flexible. However, nitinol is a super-elastic material providing good kink-resistance, but lacking pushability due to an inherently lower Young's modulus resulting in less support in delivering therapy or devices. A portion of the stainless steel sheath is left at the very distal end of the drawn filled tube to provide an atraumatic tip. Immediately proximal the tip, the bared nitinol can be heat treated, flattened in a cold work process, or shape-set to provide kink resistance and a desired degree of flexibility.

The proximal portion of the drawn filled tube is not machined, leaving stainless steel jacketing the nitinol core wire. Owing to its high yield strength and Young's modulus, stainless steel provides the guidewire with good pushability and torque transmission. Pushability and torque transmission are important to the proper functioning of a guidewire when navigating to a desired vascular site to deliver the intended diagnosis or therapeutic treatment.

These and other aspects of the present invention will become more apparent to those of ordinary skill in the art by reference to the following detailed description and the appended drawings.

