Flexible embolic device delivery system

Abstract

The present invention provides an embolic assembly delivery apparatus having superior flexibility characteristics at its distal end, that is, at the point of attachment of the embolic assembly to the delivery apparatus. It also provides a method of using the apparatus to deliver an embolic assembly to a target site in a patient's body.

1 . A device for releasing an embolic assembly at a target site in a vessel of a patient, comprising:
 a core wire comprising a first electrically-conductive substance that is at least partially fixedly encased in a first non-conductive substance and has a proximal and a distal end, its proximal end being connected to an electrical signal generator;   a flexible member having a proximal and a distal end, its proximal end being coupled to the distal end of the core wire;   an embolic assembly having a proximal and a distal end, its proximal end being operatively coupled to the distal end of the flexible member; and   an electrolytic detachment site located between the proximal end of the embolic assembly and a distal end of the first non-conductive substance,   wherein the flexible member comprises a first loop interlinked with a second loop, the first loop having a first and a second end, both of which are operatively coupled to the distal end of the core wire, a distal portion of which is optionally bare, and the second loop having a first and a second end, both of which are operatively coupled to the proximal end of the embolic assembly.   
   
   
       2 . The device of  claim 1 , wherein the first and second ends of the first loop are operatively coupled to a bare portion of the distal end of the core wire by a second electrically-conductive substance that is different from the first electrically-conductive substance, the second electrically-conductive substance having a proximal end fixedly coupled to the distal end of the bare portion of the core wire and a distal end that, along with the two ends of the first loop, is fixedly encased in a second non-conductive substance, which may be the same as, or different than, the first non-conductive substance. 
   
   
       3 . The device of  claim 2 , wherein the second electrically-conductive substance comprises an electrically conductive wire that is helically wound around the bare portion of the distal end of the core wire and the ends of the first loop. 
   
   
       4 . The device of  claim 2 , wherein the first electrically-conductive substance comprises stainless steel or nitinol, the first non-conductive substance comprises a first non-conductive polymer, the second electrically-conductive substance comprises a platinum-tungsten alloy, and the second non-conductive substance comprises a second non-conductive polymer which may be the same as, or different than, the first non-conductive polymer. 
   
   
       5 . A device for releasing an embolic assembly at a target site in a vessel of a patient, comprising:
 a core wire comprising a first electrically-conductive substance that is at least partially fixedly encased in a first non-conductive substance and has a proximal and a distal end, its proximal end being connected to an electrical signal generator;   a flexible member having a proximal and a distal end, its proximal end being coupled to the distal end of the core wire;   an embolic assembly having a proximal and a distal end, its proximal end being operatively coupled to the distal end of the flexible member; and   an electrolytic detachment site located between the proximal end of the embolic assembly and a distal end of the first non-conductive substance,   wherein the flexible member comprises a second wire and a third wire,
 the second wire comprising a second electrically-conductive substance which may be the same as, or different than, the first electrically-conductive substance, the second wire having a proximal end forming a first helical coil segment and a distal end forming a first loop segment, the first helical coil segment being fixedly coupled to the distal end of the core wire, and 
 the third wire comprising a third electrically-conductive substance which is different than the second electrically-conductive substance, the third wire having a proximal end forming a second loop segment interlinked with the first loop segment of the second wire, and a distal end forming a second helical coil segment that is fixedly encased in a second non-conductive substance with the proximal end of the embolic assembly. 
   
   
   
       6 . The device of  claim 5 , wherein the first and second conductive substances comprise stainless steel or nitinol, the first non-conductive substance comprises a first non-conductive polymer, the third conductive substance comprises a platinum-titanium alloy, and the second non-conductive substance comprises a second non-conductive polymer which may be the same as, or different than, the first non-conductive substance.