Guidewire stop

Abstract

A user-actuatable guidewire stop is disclosed which can be used to stop and/or lock a medical device on a guidewire advanced through a body lumen. In one embodiment, the guidewire stop is configured as a coil spring having an inner lumen configured to slideably and rotationally receive the guidewire in an unlocked configuration, and to frictionally engage the guidewire in a locked configuration, wherein in the inside diameter of the coil spring in the locked configuration is smaller than the diameter in the unlocked configuration. A restraining member maintains the coil spring in the unlocked configuration during deployment and is removed at the interventional site causing the coil spring to collapse onto the guidewire. The guidewire stop can be employed with an embolic filter or another intravascular device.

1 . An actuatable guidewire stop configured to limit movement of an intravascular device relative to a guidewire, comprising:
 a coil spring having an inner lumen with a first diameter configured to slideably and rotationally receive the guidewire in an unlocked configuration, and frictionally engage the guidewire in a locked configuration, wherein in the locked configuration the inner lumen has a second diameter smaller than the first diameter.   
   
   
       2 . The guidewire stop of  claim 1 , wherein the inner lumen has the first diameter when a compression force is applied to the coil spring longitudinally, and the inner lumen has the second diameter without an external force being applied to the coil spring. 
   
   
       3 . The guidewire stop of  claim 1 , wherein the inner lumen has the first diameter when a radially outward force is applied to the coil spring, and the inner lumen has the second diameter without an external force being applied to the coil spring. 
   
   
       4 . The guidewire stop of  claim 3 , further comprising a restraining member configured to urge the coil spring into the unlocked configuration, wherein the coil spring assumes the locked configuration upon removal of the restraining member. 
   
   
       5 . The guidewire stop of  claim 4 , wherein the restraining member is a tubular member disposed between an inner surface of the coil spring and the section of the guidewire, with an inner diameter of the tubular restraining member being greater than an outside diameter of the section of the guidewire. 
   
   
       6 . The guidewire stop of  claim 4 , wherein the restraining member is disposed between adjacent turns of the coil spring, wherein the restraining member urges the adjacent turns apart so that the coil spring assumes the unlocked configuration, and wherein the coil spring assumes the locked configuration upon removal of the restraining member. 
   
   
       7 . The guidewire stop of  claim 6 , wherein the restraining member comprises a filament. 
   
   
       8 . The guidewire stop of  claim 4 , wherein the restraining member is disposed along turns of the coil spring and comprises at least one protrusion disposed on a turn of the coil spring and adapted for engagement with a corresponding recess of an adjacent turn of the coil spring, and wherein the protrusion interlocks with the corresponding recess to maintain the coil spring in the unlocked configuration. 
   
   
       9 . The guidewire stop of  claim 8 , wherein the recess has a predetermined undercut angle. 
   
   
       10 . The guidewire stop of  claim 1 , further comprising an actuator operatively coupled to a proximal portion of the coil spring for changing the coil spring from the unlocked configuration to the locked configuration. 
   
   
       11 . The guidewire stop of  claim 4 , further comprising an actuator operatively coupled to a proximal portion of the restraining member for proximally removing the restraining member from a space between the coil spring and the section of the guidewire to change the coil spring from the unlocked configuration to the locked configuration. 
   
   
       12 . The guidewire stop of  claim 4 , wherein the restraining member comprises a wire or filament disposed external to and in an axial direction of the coil spring, wherein the wire or filament is affixed to turns of the coil spring by a connection having a rated break point so as to maintain the coil spring in the unlocked configuration, and wherein removal of the wire or filament causes the coil spring to assume the locked configuration on the section of the guidewire. 
   
   
       13 . The guidewire stop of  claim 12 , wherein the wire or filament has a doubled-over configuration with respect to the coil spring. 
   
   
       14 . The guidewire stop of  claim 12 , wherein the wire or filament is affixed to the coil spring by a plurality of welding spots. 
   
   
       15 . The guidewire stop of  claim 12 , further comprising an actuator operatively coupled to a proximal portion of the wire or filament, wherein the actuator is adapted to break the connection between the wire or filament and turns of the coil spring. 
   
   
       16 . An actuatable guidewire stop configured to limit movement of an intravascular device relative to a guidewire, comprising:
 a tubular member having at least one resilient member formed in a peripheral opening thereof and exerting a radially inward bias force, the tubular member surrounding a section of the guidewire, and   a restraining member interposed between the tubular member and the section of the guidewire to maintain the guidewire stop in an unlocked configuration on the section of the guidewire,   wherein upon removal of the restraining member from a space between the tubular member and the section of the guidewire, the resilient member frictionally engages the section of the guidewire and locks the guidewire stop to the section of the guidewire.   
   
   
       17 . The guidewire stop of  claim 16 , wherein the resilient member is configured as a prong and formed integrally in a peripheral surface of the tubular member. 
   
   
       18 . An intravascular filter device, comprising:
 a filter frame disposed about a guidewire;   a filter membrane operatively coupled to the filter frame; and   a coil spring attached to the filter frame, said coil spring having an inner lumen with a first diameter configured to slideably and rotationally receive the guidewire in an unlocked configuration, and frictionally engage the guidewire in a locked configuration, wherein in the locked configuration the inner lumen has a second diameter smaller than the first diameter.   
   
   
       19 . A method for locking a guidewire stop onto a guidewire at a desired location along the length of the guidewire, comprising;
 advancing the guidewire stop configured as a coil spring having an inner lumen with a first diameter configured to slideably and rotationally receive the guidewire in an unlocked configuration to the desired location; and removing a restraining member which maintains the coil spring in the unlocked configuration, thereby causing the coil spring to frictionally engage the guidewire in a locked configuration and lock the guidewire stop on the guidewire, wherein in the locked configuration the inner lumen has a second diameter smaller than the first diameter.   
   
   
       20 . The method of  claim 19 , wherein the restraining member is operatively coupled to an actuator, and removing the restraining member comprises withdrawing the actuator and the restraining member from the body lumen.