Multi-electrode assembly for an implantable medical device

Abstract

A method, system, and apparatus are provided for an electrode assembly comprising a plurality of electrodes for use with an implantable medical device for conducting an electrical signal between the implantable medical device and a target tissue. The electrode assembly includes a helical member and first and second electrodes formed upon the helical member. The first and second electrodes are adapted to deliver the electrical signal. The electrode assembly also includes a first conductive element formed upon the helical member and operatively coupled to the first electrode. The electrode assembly also includes a second conductive element formed upon the helical member and operatively coupled to the second electrode.

1 . An electrode assembly for conducting a first electrical signal between an implantable medical device and a target tissue, comprising:
 a helical member;   a first electrode and a second electrode formed upon said helical member, said first and second electrodes to deliver said first electrical signal;   a first conductive element formed upon said helical member and operatively coupled to said first electrode, said first conductive element to carry said first electrical signal to said first electrode; and   a second conductive element formed upon said helical member and operatively coupled to said second electrode.   
   
   
       2 . The electrode assembly of  claim 1 , wherein said first and second conductive elements are conductive wires that are positioned in at least a partially parallel configuration along the length of at least a portion of said helical member. 
   
   
       3 . The electrode assembly of  claim 1 , further comprising a third electrode formed upon said helical member, wherein said first, second, and third electrodes form an electrode array. 
   
   
       4 . The electrode assembly of  claim 3 , wherein said first electrode is adapted to carry said first electrical signal, said second electrode is adapted to carry a second electrical signal different from said first electrical signal, and said third electrode is adapted to carry a third electrical signal different from said first and second electrical signals. 
   
   
       5 . The electrode assembly of  claim 1 , further comprising a first lead wire operatively coupled to said first conductive element and a second lead wire operatively coupled to said second conductive element. 
   
   
       6 . The electrode assembly of  claim 5 , further comprising a lead interface operatively coupled to said helical member, said first and second lead wires being operatively coupled to said first and second conductive elements via said lead interface. 
   
   
       7 . The electrode assembly of  claim 1 , wherein said first electrode and said second electrode comprise an electrode pair, and wherein said electrode pair is a sensing electrode adapted to sense electrical activity in a target tissue. 
   
   
       8 . The electrode assembly of  claim 1 , wherein said helical material comprises a material selected from the group consisting of siloxane polymers, polydimethylsiloxanes, silicone rubbers, polyurethane, polyether urethane, polyetherurethane urea, polyesterurethane, polyamide, polycarbonate, polyester, polypropylene, polyethylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polysulfone, cellulose acetate, polymethylmethacrylate, polyethylene, and polyvinylacetate, and said first and second electrodes comprises a material selected from the group consisting of platinum, iridium, and platinum/iridium alloys. 
   
   
       9 . The electrode assembly of  claim 1 , wherein said first conductive element comprises a first conductive strip and a first conductive interface, and said second conductive element comprises a second conductive strip and a second conductive interface. 
   
   
       10 . The electrode assembly of  claim 1 , wherein said helical member further comprises a at least a third electrode operatively coupled to a third conductive element. 
   
   
       11 . The electrode assembly of  claim 1 , wherein said helical member is capable of being wrapped around a nerve, wherein said first and second electrodes come into electrical contact with said nerve to deliver a stimulation signal in a cascading manner. 
   
   
       12 . The electrode assembly of  claim 1 , wherein said first electrical signal is delivered to said first and second electrodes, said helical member further comprises a third electrode operatively coupled to a third conductor, a fourth electrode operatively coupled to a fourth conductor, and wherein a second electrical signal is delivered to said third and fourth electrodes. 
   
   
       13 . The electrode assembly of  claim 1 , wherein said first electrode is located at a first position on the helical member and said second electrode is located at a second position on the helical member. 
   
   
       14 . A method for forming a helical electrode assembly for carrying an electrical signal associated with an implantable medical device, comprising:
 forming a first layer on a generally flat substrate;   forming a first conducting structure as a second layer upon said first layer, said first conducting structure comprising a first electrode and a first conductive strip operatively coupled to said first electrode;   forming a third, non-conductive layer above said first and second layers;   forming a second conducting structure as a fourth layer upon said third layer, said second conducting structure comprising a second electrode and a second conductive strip operatively coupled to said second electrode; and   forming said generally flat substrate into a helical structure.   
   
   
       15 . The method of  claim 14 , wherein forming said first and second conducting structures comprises:
 performing a photolithography process to imprint said first conducting structure upon said first layer and said second conducting structure upon said third layer; and   performing an etch process to control at least one dimension relating to each of said first and second conducting structures within respective predetermined tolerances.   
   
   
       16 . The method of  claim 15 , further comprising performing a chemical-mechanical polishing process. 
   
   
       17 . The method of  claim 14 , further comprising forming a fifth, non-conducting layer above said third and fourth layers, and forming a third conducting structure as a sixth layer upon said fifth layer, said third conducting structure comprising a third electrode and a third conductive strip operatively coupled to said third electrode, wherein forming said fifth layer comprises performing a deposition process. 
   
   
       18 . The method of  claim 14 , wherein forming said first and second conducting structures comprises:
 performing a metal deposition process to deposit a conductive material for forming said first and second conducting structures; and   performing an etch process to control at least one dimension relating to each of said first and second conducting structures within predetermined tolerances.   
   
   
       19 . The method of  claim 14 , wherein forming said first and second conducting structures comprises offsetting said first conducting structure from said second conducting structure such that said first and second electrodes are exposed on the surface of said electrode assembly. 
   
   
       20 . The method of  claim 14 , further comprising:
 forming a fifth, non-conducting layer above said third and fourth layers, and forming a third conducting structure as a sixth layer upon said fifth layer, said third conducting structure comprising a third electrode and a third conducting strip operatively coupled to said third electrode; and   forming a seventh non-conducting layer above said fifth and sixth layers, and forming a fourth conducting structure as an eighth layer upon said seventh layer, said fourth conducting structure comprising a fourth electrode and a fourth conducting strip operatively coupled to said fourth electrode.   
   
   
       21 . The method of  claim 14 , further comprising:
 forming a first connection pad on the surface of said electrode assembly, said first connection pad being electrically coupled to said first conductive strip; and   forming a second connection pad on the surface of said electrode assembly, said second connection pad being electrically coupled to said second conductive strip.   
   
   
       22 . The method of  claim 14 , further comprising:
 forming a first via to electrically couple said first conductive strip to said first electrode; and   forming a second via to electrically couple said second conductive strip to said second electrode.   
   
   
       23 . A method for forming a helical electrode assembly for carrying a signal associated with an implantable medical device, comprising:
 forming a first layer on a generally flat substrate;   forming a first conducting structure and a second conducting structure upon said first layer, said first conducting structure comprising a first electrode and a first conductive strip operatively coupled to said first electrode, and said second conducting structure comprising a second electrode and a second conducting strip operatively coupled to said second electrode;   forming a second, non-conductive layer such that said first and second conductive strips are substantially covered by said second layer and said first and second electrodes remain exposed; and   forming said generally flat substrate and first and second layers into a helical structure.   
   
   
       24 . An implantable medical system for providing a therapeutic electrical signal to a target tissue using a helical electrode assembly, comprising:
 an implantable medical device for generating a therapeutic electrical signal;   a lead assembly operatively coupled to said implantable medical device and adapted to carry said therapeutic electrical signal, said lead assembly comprising first and second lead elements; and   an electrode assembly operatively coupled to said lead assembly and adapted to deliver said therapeutic electrical signal to a target tissue, said electrode assembly comprising:
 a helical member; 
 a first electrode and a second electrode formed upon said helical member; 
 a first conductive element formed upon said helical member and operatively coupled to said first electrode and to said first lead element; and 
 a second conductive element formed upon said helical member and operatively coupled to said second electrode and to said second lead element.