GUIDEWIRE WITH PORTIONS OF REDUCED STIFFNESS
A method and apparatus are disclosed for a guidewire that comprises an elongate member with a proximal and distal portion. The distal portion includes a distal curved portion, ending in a distal tip, and a tapered region that reduces the cross-section from a larger cross-section to a smaller cross-section. The elongate member further includes a plurality of flattened regions positioned at discrete locations along the elongate member. Each of the plurality of flattened regions are separated from one another by an unflattened region whereby when a force is exerted onto the guidewire, the guidewire undergoes bending at the plurality of flattened regions.
1 . A guidewire comprising:
an elongate member comprising:
a proximal portion;
a distal portion, the distal portion comprising:
a distal curved portion ending in a distal tip;
a tapered region, wherein the tapered region reduces a cross-section of the elongate member from a large cross-section to a small cross-section;
a plurality of flattened regions positioned at discrete locations along the elongate member; and,
wherein each of the plurality of flattened regions are separated from one another by an unflattened region;
whereby, when a force is exerted onto the guidewire, the guidewire undergoes bending at the plurality of flattened regions.
2 . The guidewire of claim 1 , wherein the elongate member is composed of nitinol.
3 . The guidewire of claim 1 , wherein the elongate member comprises a circular cross section.
4 . The guidewire of claim 1 , further comprising a radiopaque coil positioned along the distal portion.
5 . The guidewire of claim 4 wherein the radiopaque coil is held in place by a coil stopper.
6 . The guidewire of claim 1 , wherein the tapered region comprises a plurality of tapers, wherein the plurality of tapers are separated by at least one intermediate portion of constant diameter.
7 . The guidewire of of claim 6 , wherein the plurality of flattened regions comprises a proximal flattened region and a distal flattened region.
8 ) The guidewire of claim 7 , wherein the distal flattened region extends from the sharp distal tip and ends proximal to the curved distal portion.
9 . The guidewire of claim 1 , wherein the curved distal portion is J-shaped.
10 . The guidewire of claim 1 , wherein the curved distal portion is in a pigtail configuration.
11 . The guidewire of claim 1 , wherein the distal tip comprises an electrode configured to deliver energy to a target tissue.
12 . A guidewire comprising:
an elongate member having a first stiffness, the elongate member comprising:
a proximal portion;
a distal portion, the distal portion ending in a distal tip; and,
a plurality of regions of a second stiffness positioned at discrete locations along the elongate member and separated by a portion of the first stiffness;
wherein the second stiffness is less than that of the first stiffness;
whereby, when a force is exerted onto the guidewire, the guidewire undergoes bending at the plurality of regions of the second stiffness preventing kinking of the guidewire.
13 . The guidewire of claim 12 , wherein the distal portion comprises a distal curved portion, ending at the distal tip.
14 . The guidewire of claim 12 , wherein the distal portion comprises a tapered region, the tapered region tapering from a large cross-section to a small cross-section.
15 . The guidewire of claim 14 , wherein the tapered region comprises a plurality of tapered portions and wherein each of the plurality of tapered portions are separated from one another by an intermediate portion having a constant cross-section.
16 . The guidewire of claim 15 , wherein the plurality of tapered portions comprises a proximal tapered portion, a middle tapered portion, and a distal tapered portion.
17 . The guidewire of claim 12 , wherein the plurality of regions of the second stiffness comprises a plurality of flattened portions and wherein the portion of the first stiffness comprises an unflattened portion.
18 . The guidewire of claim 17 , wherein the plurality of flattened portions comprises a proximal flattened portion and a distal flattened portion.
19 . The guidewire of claim 18 , wherein the distal flattened portion extends from the distal tip and ends proximal to the curved distal region.
20 . A guidewire comprising:
an elongate member comprising:
a proximal portion;
a distal portion, the distal portion comprising:
a distal curved portion ending in a distal tip;
a plurality of broken portions; and,
an outer coil, wherein the outer coil wraps around the elongate member such that the elongate member forms a single piece;
whereby, when a force is exerted onto the guidewire, the guidewire undergoes bending at the plurality of broken portions, preventing kinking of the guidewire.