Variable Stiffness Guidewire Systems

Abstract

A variable-stiffness guidewire system which comprises an elongated flexible guidewire. The guidewire has a body and a tensioning head coupled to the body. The tensioning head is slidably moveable with respect to a guidewire collar coupled to the body via a tensioning wire to adjust a stiffness of the guidewire. The guidewire includes one or more protrusions within a conduit of the guidewire collar which applies a frictional force to the tensioning wire to maintain the tensioning head a desired distance from the collar, thereby maintaining the desired stiffness in the guidewire. A tool can be utilized with the guidewire to engage the guidewire head and move the guidewire head a desired distance from the guidewire collar to achieve a desired stiffness.

What is claimed is: 
     
         1 . A variable-stiffness guidewire assembly comprising:
 an elongated flexible guidewire, the guidewire having a body having a proximal end and a distal end, the guidewire including a tensioning wire having a first end and a second end, the first end coupled to the distal end of the body, the guidewire including a tension head coupled to the second end of the tensioning wire, wherein the tensioning wire is longitudinally movable with respect to the body to adjust a stiffness of the guidewire, the guidewire including a collar located at the proximal end of the guidewire, the collar including at least one protrusion within which applies a frictional force onto the tensioning wire to maintain the tension head at a desired distance with respect to the guidewire; and   a tool configured to receive and secure the tensioning head and the collar within, the tool including a main body and an actuator in longitudinal communication with the main body, wherein the actuator is longitudinally moveable with respect to the main body to move the tensioning head a desired distance with respect to the collar to achieve a desired stiffness in the guidewire.   
     
     
         2 . The variable-stiffness guidewire assembly of  claim 1 , wherein the tensioning head is secured within the actuator with a pin vice. 
     
     
         3 . The variable-stiffness guidewire assembly of  claim 1 , wherein the collar is secured within the main body with a pin vice. 
     
     
         4 . The variable-stiffness guidewire assembly of  claim 1 , further comprising a stopping mechanism coupled to the main body and the actuator, wherein the stopping mechanism limits movement of the actuator with respect to the main body. 
     
     
         5 . The variable-stiffness guidewire assembly of  claim 1 , further comprising a flange extending from an outer surface of the actuator. 
     
     
         6 . The variable-stiffness guidewire assembly of  claim 1 , wherein the actuator further comprises a first end and a second end, the first end of the actuator facing the second end of the main body, the actuator includes a hollow cylindrical tube extending from the second end located in the main body, the cylindrical tube adapted to allow at least the tensioning head to pass therethrough to the actuator. 
     
     
         7 . A tool for use with a variable-stiffness guidewire, the tool comprising:
 a cylindrical main body having a first end and a second end, the main body having an aperture at the first end to receive a portion of a guidewire, the main body having a first securing feature to grasp a collar of the guidewire within; and   an actuator coupled to the main body at the second end and moveable along a longitudinal axis with respect to the main body between a non-extended position and an extended position, the actuator having a second securing feature to grasp a tension head of the guidewire within, wherein the tool increases stiffness of the guidewire by moving the actuator from the non-extended position to the extended position.   
     
     
         8 . The tool of  claim 7 , wherein the first and second securing features are pin vices. 
     
     
         9 . The tool of  claim 7 , further comprising a stopping mechanism coupled to the main body and the actuator, wherein the stopping mechanism limits movement of the actuator with respect to the main body. 
     
     
         10 . The tool of  claim 7 , further comprising a flange extending from an outer surface of the actuator. 
     
     
         11 . The tool of  claim 7 , wherein the actuator further comprises a first end and a second end, the first end of the actuator facing the second end of the main body, the actuator includes a hollow cylindrical tube extending from the second end located in the main body, the cylindrical tube adapted to allow at least the tensioning head to pass therethrough to the actuator. 
     
     
         12 . The tool of  claim 7 , wherein the first and second securing features are freely rotatable about the longitudinal axis.