Pressure-sensitive flexible polymer bipolar electrode

Abstract

The present invention is directed to bipolar ablation systems. A bipolar electrode system for ablation therapy is disclosed, including a pressure-sensitive conducting composite layer and a pair of electrodes in electrical conductive contact or communication with the pressure-sensitive conducting composite layer. Energy (e.g., ablation energy) is delivered via the pressure-sensitive conductive composition when sufficient pressure is applied to transform the pressure-sensitive conductive composite to an electrical conductor. An electrically insulative flexible layer, which may include a passageway for a fill material is also disclosed. In some embodiments, the systems can also be used for targeted delivery of compounds, such as drugs, using a bipolar electrode.

1 .- 33 . (canceled) 
     
     
         34 . A catheter, comprising:
 a catheter shaft comprising a distal portion and a proximal portion; and   an electrode assembly coupled to the distal portion, the electrode assembly comprising
 an exterior configured to engage target tissue and configured to bend and conform to a compliant tissue wall of the target tissue, 
 first and second electrodes on the exterior; 
 first and second channeling members configured to be transformed from an insulator to a conductor in response to a respective applied pressure; 
 a pair of electrical wires in electrical contact with the first and second channeling members; 
   wherein the first channeling member is disposed radially inward of and in electrical communication with the first electrode and the second channeling member is disposed radially inward of and in electrical communication with the second electrode;   wherein the electrode assembly is configured to channel electrical energy with respect to a first portion of the exterior of the electrode assembly while not channeling electrical energy with respect to a second portion of the exterior of the electrode assembly when the first portion is in contact with the target tissue and the second portion is not in contact with the target tissue.   
     
     
         35 . The catheter of  claim 34  wherein at least one of said first and second channeling members comprise pressure-sensitive conductive composite (PSCC) layers. 
     
     
         36 . The catheter of  claim 34  wherein at least one of said first and second channeling members comprise a quantum tunneling composite member. 
     
     
         37 . The catheter of  claim 34 , wherein the electrode assembly is further configured to allow a fluid to exit from the electrode assembly between the first electrode and the second electrode. 
     
     
         38 . The catheter of  claim 34 , wherein the electrode assembly is further configured to allow a fluid to exit from the electrode assembly adjacent the first electrode and the second electrode. 
     
     
         39 . The catheter of  claim 34 , wherein the electrode assembly comprises a porous material such that a fluid may pass therethrough. 
     
     
         40 . The catheter of  claim 34 , wherein ablative energy from an ablative energy source coupled to the pair of electrical wires is channeled to the first portion of the exterior via a corresponding first portion of the first and second channeling members when sufficient pressure is applied thereto and thereby transform said corresponding first portion of the first and second channeling members into electrical conductors. 
     
     
         41 . The catheter of  claim 34  further comprising: an electrically insulative flexible layer adjacent the first and second channeling members. 
     
     
         42 . The catheter of  claim 41  further comprising: a sensor located in the electrically insulative flexible layer configured to monitor a temperature. 
     
     
         43 . The catheter of  claim 41  further comprising: a heat sink thermally coupled to one of the channeling members and the electrically insulative flexible layer. 
     
     
         44 . The catheter of  claim 34  wherein the first electrode comprises a circumferentially-extending ring of electrically-conductive material having a first outside surface, said second electrode comprises a circumferentially-extending ring of electrically-conductive material having a second outside surface, the exterior of the electrode assembly including the first and second outside surfaces. 
     
     
         45 . The catheter of  claim 34  wherein the first and second channel members comprises at least a first annular portion radially-inwardly of the first electrode and a second annular portion radially-inwardly of the second electrode, the first electrode being longitudinally offset from the second electrode. 
     
     
         46 . The catheter of  claim 34  further comprising a tip electrode at a distal end of the catheter shaft and located distal of the first and second electrodes, said catheter further comprising a further electrical wire coupled to the tip electrode. 
     
     
         47 . The catheter of  claim 34  wherein electrical energy at a first portion of at least one of the first and second electrodes in contact with the target tissue is channeled to at least one of the first and second wires via a corresponding first portion of the first and second channeling members when sufficient pressure is applied thereto and thereby transform said corresponding first portion of the first and second channeling members into electrical conductors. 
     
     
         48 . The catheter of  claim 46  wherein the electrical energy comprises electrical characteristics of the target tissue. 
     
     
         49 . A catheter, comprising:
 a catheter shaft comprising a distal portion and a proximal portion; and   an electrode assembly coupled to the distal portion including:
 first and second electrodes whose outside surfaces are configured to engage target tissue; 
 first and second channeling members disposed radially inward of said first and second electrodes, respectively, and configured as electrical insulators in an absence of a predetermined applied pressure and further configured as electrical conductors in a presence of the predetermined applied pressure; and 
 pair of electrical conducting wires in contact with the first and second channeling members and coupled to one of an ablative energy source and a measuring device; 
   said electrode assembly includes (i) a conductive zone corresponding to a portion of said outside surfaces of said first and second electrodes that are subject to said predetermined applied pressure when in contact with the target tissue and in which one of ablative energy and electrical energy corresponding to electrical characteristics of the target tissue are delivered and (ii) a complementary insulative zone where neither the ablative energy nor the electrical energy is delivered when said complementary insulative zone is not subject to said predetermined applied pressure when it is not in contact with the target tissue;   wherein one of (i) the ablative energy from the ablative energy source and (ii) the electrical energy corresponding to electrical characteristics of the target tissue is channeled through the conductive zone via a corresponding first portion of said first and second channeling members when the predetermined pressure is applied thereto to transform the corresponding first portion of said first and second channeling members into electrical conductors.   
     
     
         50 . The catheter of  claim 49  further comprising a tip electrode coupled with a further electrical conducting wire. 
     
     
         51 . The catheter of  claim 49  wherein said first and second channeling members comprises quantum tunneling composite members. 
     
     
         52 . A catheter, comprising:
 a catheter shaft comprising a distal portion and a proximal portion; and   an electrode assembly coupled to the distal portion including
 first and second electrodes having respective outside surfaces configured to engage target tissue; 
 first and second channeling members being arranged relative to said first and second electrodes, respectively; and 
 first and second electrical conducting wires extending to a proximal end of said catheter and are configured for connection to an electrical apparatus, wherein the first and second electrical wires are in contact with the first and second channeling members, respectively; 
   said first channeling member being configured to selectively couple said first electrical conducting wire to said first electrode when said outside surface of said first electrode experiences a predetermined pressure applied thereto and configured to not selectively couple said first electrical conducting wire to said first electrode when said outside surface of said first electrode does not experience said predetermined pressure applied thereto,   said second channeling member being configured to selectively couple said second electrical conducting wire to said second electrode when said outside surface of said second electrode experiences said predetermined pressure applied thereto and configured to not selectively couple said second electrical conducting wire to said second electrode when said outside surface of said second electrode does not experience said predetermined pressure applied thereto.   
     
     
         53 . The catheter of  claim 52  wherein said first and second channeling members are configured as electrical insulators in absence of the predetermined applied pressures and electrical conductors in the presence of the predetermined applied pressures.