Implantable electrode assembly having reverse electrode configuration

Abstract

Methods and apparatus for generating an electric field inside a patient include at least a first electrode and a second electrode on a common implantable substrate. Each of the electrodes has a respective proximal end and a respective distal end. Electrical energy can be applied that causes electrical current to flow simultaneously through the first and second electrodes preferentially from the proximal end of one electrode to the distal end of the other electrode.

1 . A method of generating an electric filed inside a patient, the method comprising:
 providing at least a first electrode and a second electrode on a common implantable substrate, wherein each of the first and second electrodes has a respective proximal end and a respective distal end, wherein the proximal end of the first electrode is positioned closer to the distal end of the second electrode than to the proximal end of the second electrode, wherein the proximal end of the second electrode is positioned closer to the distal end of the first electrode than to the proximal end of the first electrode;   implanting the implantable substrate inside the patient; and   applying electrical energy across the first and second electrodes to cause electrical current to flow simultaneously through the first and second electrodes preferentially from the proximal end of one electrode to the distal end of the other electrode.   
   
   
       2 . The method of  claim 1 , and further comprising:
 implanting the implantable electrode assembly such that each cathode electrode is coupled to at least one anode electrode via electrically conductive target tissue.   
   
   
       3 . The method  claim 2 , wherein the target tissue provides a generally uniform coupling along the lengths of the coupled electrodes. 
   
   
       4 . The method of  claim 1 , and further comprising:
 establishing a generally uniform current density substantially through the length of each electrode.   
   
   
       5 . The method of  claim 1 , wherein the step of applying electrical energy causes electrical current to flow preferentially from the proximal end of the first electrode to the distal end of the second electrode and preferentially from the distal end of the first electrode to the proximal end of the second electrode. 
   
   
       6 . An electrode assembly comprising:
 a generally flexible base having a first surface region and an axially spaced-apart second surface region; and   at least three generally parallel elongate electrode structures secured and axially aligned over a surface of the base, each electrode structure having a proximal end and a distal end;   wherein an outer pair of the electrode structures is electrically isolated from an inner electrode structure;   wherein the proximal ends of the outer pair of electrode structures and the distal end of the inner electrode structure are disposed on the first surface region of the vase, and the distal ends of the outer electrode structures and the proximal end of the inner electrode structure are disposed on the second surface region of the base that is separate from the surface region.   
   
   
       7 . The electrode assembly of  claim 6 , wherein the conductive lends electrically coupled to the outer electrode structures are electrically coupled to a first pole of an electrical signal generator, and the conductive lead electrically coupled to the inner electrode structure is electrically coupled to a second pole of the electrical generator. 
   
   
       8 . The electrode assembly of  claim 6 , wherein the base is adapted to be attachable to an outside surface of a blood vessel. 
   
   
       9 . The electrode assembly of  claim 6 , wherein the base includes a plurality of finger-type extensions for facilitating securing the base to target tissue. 
   
   
       10 . The electrode assembly of  claim 6 , wherein each electrode structure has a generally uniformly distributed impedance along its length. 
   
   
       11 . The electrode assembly of  claim 6 , wherein each electrode structure includes a coiled portion adapted to make contact with target tissue. 
   
   
       12 . The electrode assembly of  claim 6 , wherein the electrode structures are aligned to facilitate transmission of a generally uniformly distributed electric field through target tissue situated between the electrode structures. 
   
   
       13 . An electrode assembly adapted for implantation at an electrotherapy site in a patient, the electrode assembly comprising:
 a substrate; and   at least three elongate electrodes secured to the substrate and electrically coupled to the electrotherapy site, each electrode having a proximal end connected to an electrically conductive lead and a distal end not connected to a lead or other electrode;   wherein a generally uniform charge density is generated between an outer pair of the at least three electrodes and an inner electrode when an electrical current is applied to the electrodes.   
   
   
       14 . The electrode assembly of  claim 13 , wherein the proximal ends of the outer electrode structures and the distal end of the inner electrode structure are disposed on the first surface region of the base, and the distal ends of the outer electrode structures and the proximal end of the inner electrode structure are disposed on the second surface region of the base that is separate from the first surface region. 
   
   
       15 . The electrode assembly of  claim 14 , and further comprising:
 a remote electrotherapy signal generator circuit electrically coupled with the at least three electrodes and supplying electrotherapy signaling to the electrotherapy site via the at least three electrodes; and   wherein at least the outer pair of the electrodes is electrically coupled at the proximately situated region with a lead to s first pole of the electrotherapy signal generator, and an inner one of the electrodes is electrically coupled at the distally situated region with a lead to a second pole of the electrotherapy signal generator.   
   
   
       16 . The electrode assembly of  claim 14 , wherein the at least three electrodes include at least one anode and at least one cathode; and
 wherein the at least one cathode is electrically coupled with at least one corresponding lead at the proximally situated region, and the at least one anode is electrically coupled with at least one corresponding lead at the distally situated region.   
   
   
       17 . The electrode assembly of  claim 13 , wherein the at least three electrodes are situated generally coextensively. 
   
   
       18 . An electrotherapy arrangement implanted at an electrotherapy site, the electrotherapy arrangement comprising:
 an electrode assembly, including:   a substrate; and   at least three adjacent elongate electrodes secured to the substrate and electrically coupled to the electrotherapy site, wherein each electrode is situated such that proximal and distal ends of each successive adjacent electrode's ends are longitudinally opposing; and   an electrotherapy signal generator circuit electrically coupled with the at least three electrodes and applying electrotherapy signaling to the electrotherapy site via the at least two electrodes;   wherein the electrotherapy signaling generates an electric field through the electrotherapy site that is generally uniformly distributed along a longitudinal reference axis located in the electrotherapy site between an anode and a cathode of the at least three electrodes.   
   
   
       19 . The electrotherapy arrangement of clam  18 , wherein the electrotherapy signaling is adapted to stimulate baroreceptors. 
   
   
       20 . The electrotherapy arrangement of  claim 18 , wherein the electrotherapy signaling is adapted to stimulate at least one nerve. 
   
   
       21 . The electrotherapy arrangement of  claim 18 , wherein the electrotherapy signaling is adapted to stimulate muscle tissue. 
   
   
       22 . A method of generating an electric field inside a patient, the method comprising:
 providing at least a first electrode, a second electrode and a third electrode on a common implantable substrate, wherein each of the first, second and third electrodes has a respective proximal end and a respective distal end, wherein the proximal end of the first electrode is positioned closer to the distal end of the second electrode than to the distal end of the second electrode than to the proximal end of the second electrode, wherein the proximal end of the second electrode is positioned closer to the distal end of the first electrode than to the proximal end of the first electrode;   implanting the implantable substrate inside the patient; and   applying electrical energy across the first, second and third electrodes to cause electrical current to flow simultaneously through the first and second electrodes preferentially from the proximal end of one electrode to the distal end of the other electrode and across the third electrode preferentially from the proximal end of the third electrode to the distal end of the second electrode and from the distal end of the third electrode to the proximal end of the second electrode.   
   
   
       23 . The method of  claim 22 , and further comprising:
 implanting the implantable electrode assembly such that each cathode electrode is coupled to at least one anode electrode via electrically conductive target tissue.   
   
   
       24 . The method of  claim 23 , wherein the target tissue provides a generally uniform coupling along the lengths of the coupled electrodes. 
   
   
       25 . The method of  claim 22 , and further comprising:
 establishing a generally uniform current density substantially through the length of each electrode.   
   
   
       26 . An electrode assembly comprising:
 a first electrode having a first arcuate shape; and   a second electrode having a second arcuate shape; and   wherein the second electrode at least partially encircles the first electrode.   
   
   
       27 . The electrode assembly of  claim 26 , further comprising:
 a third electrode having a third arcuate shape; and   wherein the third electrode at least partially encircles the first and second electrodes.   
   
   
       28 . The electrode assembly of  claim 27 , wherein the second electrode is electrically insulated from the first and third electrodes. 
   
   
       29 . The electrode assembly of  claim 26 , wherein the first and third electrodes are electrically connected to one another. 
   
   
       30 . The electrode assembly of  claim 26 , wherein each electrode comprises a coil. 
   
   
       31 . The electrode assembly of  claim 26 , wherein each electrode is disposed on a common implantable substrate. 
   
   
       32 . The electrode assembly of  claim 26 , wherein one of the electrodes is electrically insulated from the other two electrodes. 
   
   
       33 . The electrode assembly of  claim 26 , wherein one of the electrodes is electrically connected to one of the other two electrodes. 
   
   
       34 . The electrode assembly of  claim 26 , wherein each electrode has a first end and a second end. 
   
   
       35 . The electrode assembly of  claim 26 , further comprising a lead electrically connected to a first end of the first electrode. 
   
   
       36 . The electrode assembly of  claim 26 , further comprising a lead electrically connected to a second end of the second electrode. 
   
   
       37 . The electrode assembly of  claim 26 , further comprising a lead electrically connected to a first end of the third electrode. 
   
   
       38 . The electrode assembly of  claim 26 , further comprising an electrotherapy signal generator electrically connected to at least the first electrode and the second electrode, and delivering an electrotherapy signal thereto. 
   
   
       39 . The electrode assembly of  claim 38 , wherein a generally uniform electric field is generated between the electrodes when the electrotherapy signal is delivered thereto. 
   
   
       40 . The electrode assembly of  claim 38 , wherein a generally uniform current density is generated in a tissue when the electrodes are placed in contact with the tissue and the electrotherapy signal is delivered to the electrodes. 
   
   
       41 . A method of generating an electric field inside a patient, the method comprising:
 electrically contacting a target tissue of the patient with a first electrode;   electrically contacting the target tissue along an arcuate path of a second electrode that least partially encircles the first electrode; and   applying electrical energy across the first and second electrodes to establish a generally uniform current density between the first and second electrodes.   
   
   
       42 . The method of  claim 41 , further comprising electrically connecting the first electrode and the second electrode to a signal source. 
   
   
       43 . The method of  claim 41 , wherein contacting the target tissue with the first electrode comprises contacting an exterior surface of a wall of a blood vessel with the first electrode. 
   
   
       44 . The method of  claim 41 , wherein the first electrode is fixed to a flexible substrate and the method comprises conforming the flexible substrate to the exterior surface of the wall of the blood vessel. 
   
   
       45 . The method of  claim 41 , further comprising delivering a signal to the wall of the blood vessel to cause a change in the patient. 
   
   
       46 . The method of  claim 45 , wherein the change comprises a change in blood pressure. 
   
   
       47 . The method of  claim 46 , wherein the change comprises a reduction in blood pressure. 
   
   
       48 . The method of  claim 45 , wherein the change comprises an increase in parasympathetic nervous system activity. 
   
   
       49 . The method of  claim 45 , wherein the change comprises a decrease in sympathetic system activity. 
   
   
       50 . The method of  claim 45 , wherein the change comprises a change in a radio of sympathetic nervous system activity to parasympathetic nervous system activity. 
   
   
       51 . The method of  claim 45 , wherein the change occurs in cells in the wall of the blood vessel. 
   
   
       52 . The method of  claim 45 , wherein the change occurs in nerve fibers in the wall of the blood vessel. 
   
   
       53 . The method of  claim 45 , wherein the change comprises a change in receptors in the wall of the blood vessel. 
   
   
       54 . The method of  claim 53 , wherein the change comprises a change in baroreceptors in the wall of the blood vessel.