Retrieval Basket with Releasable Tip

Abstract

A medical retrieval device is used to retrieve and/or fragment stones (and/or other objects) from the body of a patient. The device has a retrieval basket with a releasable tip. The tip release is designed to release in a controlled pre-determined manner and under a predetermined force before any other component of the device fails due to a force exerted on the basket.

1 . A medical device, comprising:
 a tubular sheath having a proximal end, a distal end, and a lumen;   a sidecar defining a guidewire lumen disposed about the distal end of the tubular sheath;   an elongate traction member disposed within the lumen of the tubular sheath; and   a basket comprising a plurality of wires, the plurality of wires each having a proximal end attached to a distal end of the elongate traction member and a distal end secured at a tip joint;   wherein at least one of the plurality of wires is released from the tip joint when a predetermined force is applied to the tip joint.   
   
   
       2 . The medical device of  claim 1 , further comprising an actuating mechanism coupled to a proximal end of the elongate traction member. 
   
   
       3 . The medical device of  claim 1 , wherein the elongate traction member is slidably disposed within the tubular sheath. 
   
   
       4 . The medical device of  claim 3 , wherein the basket is moveable from a first generally collapsed position when disposed within the tubular sheath to a second generally expanded position when the basket extends from the distal end of the tubular sheath. 
   
   
       5 . The medical device of  claim 4 , wherein when in the second generally expanded position a distal end of the basket is wider than a proximal end of the basket. 
   
   
       6 . The medical device of  claim 1 , wherein each of the plurality of wires are comprised of three filaments. 
   
   
       7 . The medical device of  claim 6 , wherein the three filaments are twisted together to form a cable. 
   
   
       8 . The medical device of  claim 7 , wherein the filaments comprise nickel titanium alloy. 
   
   
       9 . The medical device of  claim 1 , further comprising a reinforcement ring disposed about the distal end of the tubular sheath. 
   
   
       10 . The medical device of  claim 1 , wherein the distal joint is at least one of a weld joint, an over-molding joint, an adhesive joint, or a solder joint. 
   
   
       11 . A medical device, comprising:
 a tubular sheath having a proximal end, a distal end, and a lumen;   a handle attached to the proximal end of the tubular sheath;   an actuating mechanism; and   a basket comprising a plurality of wires, the plurality of wires each having a proximal end secured to the actuating mechanism and a distal end secured at a tip joint;   wherein at least one of the plurality of wires is released from the tip joint when a predetermined force is applied to the tip joint; and   the predetermined force is less than a force required to cause the failure of one of the plurality of wires, the proximal end of the basket, or the traction member.   
   
   
       12 . The medical device of  claim 11 , wherein the plurality of wires comprise four wires. 
   
   
       13 . The medical device of  claim 12  wherein each of the four wires comprises four bends. 
   
   
       14 . The medical device of  claim 11 , wherein the basket is moveable from a collapsed position within the lumen of the tubular sheath to an expandable position disposed outside the lumen of the tubular sheath for capturing objects in the body. 
   
   
       15 . The medical device of  claim 11 , wherein the tip joint is a tubular member including a lumen configured to receive and compress the distal ends of the plurality of wires. 
   
   
       16 . The medical device of  claim 15 , wherein the tubular member includes a sealed distal end. 
   
   
       17 . The medical device of  claim 16 , wherein the distal end of the tubular member comprises a spherico-conical shape. 
   
   
       18 . The medical device of  claim 11 , wherein the sheath and basket are dimensioned to fit within a working lumen of an endoscope. 
   
   
       19 . A medical device, comprising:
 a tubular sheath having a proximal end, a distal end, and a lumen;   a sidecar defining a guidewire lumen disposed about the distal end of the tubular sheath;   a handle attached to the proximal end of the tubular sheath and attached to a distal end of the handle;   an elongate traction member disposed within the lumen of the tubular sheath; and   a basket comprising a plurality of wires, the plurality of wires each having a proximal end attached to a distal end of the elongate traction member and a distal end secured at a tip joint;   wherein the basket is configured to be moveable from a first position within the tubular sheath to a second position distal the distal end of the tubular sheath.   
   
   
       20 . The medical device of  claim 19 , wherein at least one of the plurality of wires is released from the tip joint when a predetermined force is applied to the tip joint.