Guide wire having bending segment

Abstract

A guide wire including a continuous, unitary wire having a first segment, a second segment, and a third segment is shown and described. The third segment has a bending moment of inertia less than the bending moment of inertia of the first and second segments. The guide wire can be used to advance a medical device within a body lumen.

What is claimed:  
     
         1 . A guide wire structure for insertion into an interior space defined by a wall, the guide wire comprising a continuous, unitary wire comprising a first segment, a second segment, and a third segment disposed intermediate the first and second segments, wherein the third segment has a bending moment of inertia less than a bending moment of inertia of the first segment and less than a bending moment of inertia of the second segment.  
     
     
         2 . The guide wire structure of  claim 1  wherein the third segment has a cross-sectional area less than the cross sectional areas of the first segment and the second segment.  
     
     
         3 . The guide wire structure of  claim 1  wherein at least one of the first, second, and third segments have circular cross sections.  
     
     
         4 . The guide wire structure of  claim 1  wherein at least one of the first, second and third segments have non-circular cross-sections.  
     
     
         5 . The guide wire structure of  claim 1  wherein the wire is formed of Nitinol.  
     
     
         6 . The guide wire structure of  claim 1  further comprising an indicator associated with at least one of the segments for differentiating the segments.  
     
     
         7 . The guide wire structure of  claim 7  wherein the indicator comprises a visual indicator.  
     
     
         8 . The guide wire structure of  claim 7  wherein the indicator comprises a marking associated with at least one of the segments.  
     
     
         9 . The guide wire structure of  claim 1  comprising a sleeve encircling at least one of the first and second segments.  
     
     
         10 . The guide wire structure of  claim 1  comprising a sleeve encircling each of the first and second segments.  
     
     
         11 . The guide wire structure of  claim 1  comprising a sleeve encircling the first segment and a sleeve encircling the second segment, wherein the first and second sleeves are visually distinguishable.  
     
     
         12 . The guide wire structure of  claim 1  wherein the combined length of the first segment, the second segment, and the third segment is at least about 7 feet.  
     
     
         13 . The guide wire structure of  claim 1  wherein the combined length of the first segment, the second segment, and the third segment is between about 7 feet and about 25 feet.  
     
     
         14 . The guide wire structure of  claim 1  wherein the combined length of the first segment, the second segment, and the third segment is at least about 20 feet.  
     
     
         15 . The guide wire structure of  claim 1  wherein the first segment has a length of at least about 6 feet, and a generally circular cross-section having a diameter of between about 0.011 inch to about 0.035 inch.  
     
     
         16 . The guide wire structure of  claim 15  wherein the third segment has a diameter of between about 0.005 inch and about 0.010 inch.  
     
     
         17 . The guide wire structure of  claim 1  wherein the first segment has a length of at least about 6 feet, wherein the first segment has maximum cross-sectional dimension of no more than about 0.035 inch, and wherein the third segment has a maximum cross-sectional dimension of no more than about 0.010 inch.  
     
     
         18 . The guide wire structure of  claim 1  wherein the third segment is bent.  
     
     
         19 . The guide wire structure of  claim 1  wherein the third segment provides an elastic hinge.  
     
     
         20 . A guide wire structure comprising: 
 a first segment of a generally constant diameter;    a second segment of generally constant diameter;    a third segment having a generally constant diameter less than that of the first and second segment diameters;    a tapered segment of decreasing diameter extending from the first segment to the third segment; and    a tapered segment of decreasing diameter extending from the second segment to the third segment.    
     
     
         21 . A method of using a guide wire comprising the steps of: 
 providing a guide wire comprising a unitary wire having reduced bending moment of inertia at a position spaced from the ends of the guide wire;    providing a medical device having a channel;    bending the wire at the position of the reduced bending moment of inertia; and    inserting the bend in the wire into the channel of the medical device.    
     
     
         22 . The method of  claim 21  further comprising the step of passing the bend in the wire through a distal end of the medical device.  
     
     
         23 . The method of  claim 21  further comprising the step of advancing the medical device along the wire.