Adjustable stylet

Abstract

An adjustable stylet includes a core wire having a portion surrounded by a compression member preferably comprised of a flat wire spring. Depending upon the configuration, compression or relaxation of the compression member in response to forces at the tip or handle of the stylet results in adjustments to the characteristics of the stylet. In a first embodiment, the stiffness of the stylet is adjustable. In a second embodiment, the length of the stylet is adjustable. In a third embodiment, both the stiffness and the length of the stylet are adjustable.

What is claimed is:  
     
         1 . An adjustable stylet for use within a lumen of an intravascular device comprising: a core wire having a blunt distal end and a proximal end and having an outer diameter of less than 0.020 inches and a relatively uniform beam strength over an axial length of said core wire; a compression member having a distal end operably secured to said core wire and a proximal end axially movable along said core wire, said compression member comprising a flat wire space wound around at least a portion of said core wire with a wide dimension of said flat wire oriented axially and an axial spacing between successive windings of said compression member; a handle operably mounted proximate said proximal end of said core wire, said handle axially movable to operably engage said proximal end of said compression member such that said axial spacing between at least a portion of said successive windings is adjusted by movement of said handle, whereby a stiffness of said stylet is adjusted by operation of said handle.  
     
     
         2 . The adjustable stylet of  claim 1  wherein said compression member is secured to said core wire proximate said blunt distal end of said core wire.  
     
     
         3 . The adjustable stylet of  claim 1  further comprising a rigid tube member operably positioned around said core wire between said proximal end of said compression member and said handle to transfer axial force applied by said handle to said compression member.  
     
     
         4 . The adjustable stylet of  claim 1  wherein said flat wire is a stainless steel wire having an aspect ratio of at least 2:1 and having a narrow cross-sectional dimension of less than 0.003 inches.  
     
     
         5 . The adjustable sylet of  claim 1  wherein said blunt end is comprised of a ball welded to said distal end of said core wire.  
     
     
         6 . The adjustable stylet of  claim 1  wherein said handle is slidable relative to said core member.  
     
     
         7 . The adjustable stylet of  claim 1  wherein said handle includes a handle member secured to said core wire proximate said proximal end and a moveable member operably engaged with said handle member such that said moveable member is axially moveable relative to said handle member within a distance determined by said handle member, said moveable member including a proximal portion extending distally beyond said handle member for operably engaging said proximal end of said compression member.  
     
     
         8 . The adjustable stylet of  claim 7  wherein said moveable member and said handle member include structure such that said moveable member is slidable relative to said handle member.  
     
     
         9 . The adjustable stylet of  claim 7  wherein said moveable member and said handle member include structure such that said moveable member is screwable relative to said handle member.  
     
     
         10 . The adjustable stylet of  claim 7  wherein at least one of said moveable member and said handle member includes structure to releasably position said moveable member relative to said handle member at multiple axial locations.  
     
     
         11 . The adjustable stylet of  claim 1  wherein said core wire comprises a wire having a uniform cross-sectional diameter.  
     
     
         12 . The adjustable stylet of  claim 1  wherein said core wire comprises a solid wire.  
     
     
         13 . The adjustable stylet of  claim 1  wherein said core wire comprises: a first core wire segment and a second core wire segment; and a length adjustment member secured between adjacent ends of said first and second core wire segments, said length adjustment member comprising a space wound wire with an axial spacing between successive windings of said length adjustment member such that an axial force applied to at least one end of said length adjustment member decreases said axial spacing between at least a portion of said successive windings of said length adjustment member.  
     
     
         14 . An adjustable stylet for use within a lumen of an intravascular device comprising: a first core wire and a second core wire, each core wire having an outer diameter of less than 0.020 inches and a relatively uniform beam strength over an axial length of said core wire; and a compression member secured between adjacent ends of said first and second core wires, said compression member comprising a space wound wire with an axial spacing between successive windings of said compression member such that an axial force applied to at least one end of said compression member decreases said axial spacing between at least a portion of said successive windings.  
     
     
         15 . The adjustable stylet of  claim 14  wherein said compression member is a flat stainless steel wire having an aspect ratio of at least 2:1 and having a narrow dimension of less than 0.003 inches.  
     
     
         16 . The adjustable stylet of  claim 14  wherein each of said adjacent ends of said first and second core wires are centerless ground and said compression member overlaps and is secured to said centerless ground portion of said adjacent ends.  
     
     
         17 . The adjustable stylet of  claim 14  further comprising a cover tube surrounding at least a portion of said compression member and secured at only one end to one of said first and second core wires.  
     
     
         18 . An adjustable stylet for use within a lumen of an intravascular device comprising: a core wire having a blunt distal end and a proximal end and having an outer diameter of less than 0.020 inches and a relatively uniform beam strength over an axial length of said core wire; compression means for adjusting a stiffness of said stylet, said compression means having a distal end operably secured to said core wire and a proximal end axially movable along said core wire; handle means for engaging said compression means to effect adjustment of said compression means, said handle means operably mounted proximate said proximal end of said core wire.  
     
     
         19 . The adjustable stylet of  claim 18  further comprising a rigid tube member operably positioned around said core wire between said proximal end of said compression means and said handle means to transfer axial force applied by said handle means to said compression means.  
     
     
         20 . The adjustable stylet of  claim 18  wherein said core wire comprises a solid wire having a uniform cross-sectional diameter.