Balloon catheter with enhanced locatability

Abstract

A balloon catheter for insertion in a vessel includes a catheter shaft and an inflatable balloon attached to the catheter shaft. Markings along a longitudinal axis of the catheter are provided in an interior of the balloon, such as for measuring a distance within the vessel. A first distance separating a first marking from a second adjacent marking may be different from a second distance separating the second marking from the third adjacent marking. The markings may also be used for ensuring the proper position of the balloon and, in particular, the working surface thereof, relative to the treatment area.

1 . A balloon catheter comprising:
 an elongated, tubular shaft;   an inflatable balloon supported by the shaft and having an interior;   a plurality of first radiopaque markings proximal of the balloon; and   a plurality of second radiopaque markings within the interior of the balloon.   
     
     
         2 . The balloon catheter of  claim 1 , wherein the elongated tubular shaft comprises an inner tubular shaft, and the first radiopaque markings are provided on an outer tubular shaft coaxial with the inner tubular shaft. 
     
     
         3 . The balloon catheter of  claim 1 , wherein the first radiopaque markings are spaced equidistantly. 
     
     
         4 . The balloon catheter of  claim 1 , wherein the second radiopaque markings are spaced equidistantly. 
     
     
         5 . The balloon catheter of  claim 1 , wherein the first radiopaque markings are not spaced equidistantly. 
     
     
         6 . The balloon catheter of  claim 1 , wherein the second radiopaque markings are spaced equidistantly. 
     
     
         7 . The balloon catheter of  claim 1 , wherein the plurality of second radiopaque markings comprise at least three markings. 
     
     
         8 . The balloon catheter of  claim 1 , wherein the plurality of second radiopaque markings have a first distance between each of the second radiopaque markings and the first radiopaque markings have a second distance between each of the first radiopaque markings, wherein the first distance is less than the second distance. 
     
     
         9 . The balloon catheter of  claim 1 , wherein the plurality of first radiopaque markings have different spacings between adjacent pairs of markings. 
     
     
         10 . The balloon catheter of  claim 1 , wherein the plurality of second radiopaque markings have different spacings between adjacent pairs of markings. 
     
     
         11 . A balloon catheter, comprising:
 an elongated, tubular shaft;   an inflatable balloon supported by the shaft, the balloon including a working surface having a midpoint in an inflated condition;   at least one first radiopaque marking located on the balloon and corresponding to the location of one end of the working surface in the inflated condition; and   at least one second radiopaque marking located on the shaft and corresponding to the location of the midpoint of the working surface in the inflated condition, further including a third radiopaque marking corresponding to the other end of the working surface and located on the shaft.