System for nerve sensing and stimulation employing multi-electrode array

Abstract

A nerve stimulation system includes a pulse generator and implantable lead. The pulse generator includes a sensing module and a pace circuit. The lead has an electrode array near the distal end and a connector at the proximal end for connection to the pulse generator. Conductors in the lead electrically connect the electrode array with the sensing module and pace circuit. The electrode array includes a first pair of small electrodes and a large electrode close to each other. The small electrodes and large electrode are physically separated from each other by insulative spaces extending generally transversely to a longitudinal axis of the lead. When the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit only.

What is claimed is: 
     
         1 . A nerve stimulation system comprising:
 an implantable pulse generator comprising a sensing module and a pace circuit; and   an implantable lead comprising a distal end, an electrode array near the distal end, a proximal end including a lead connector end configured to couple the proximal end to the pulse generator, and conductors extending through the lead from the electrode array and caused to be in electrical communication with the sensing module and pace circuit when the proximal end is coupled to the pulse generator,   wherein the electrode array comprises at least a first pair of small electrodes and a large electrode in close proximity to each other, the small electrodes and large electrode physically separated from each other by non-conductive spaces extending generally transversely to a longitudinal axis of the lead,   wherein, when the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit, but not the sensing module.   
     
     
         2 . The system of  claim 1 , wherein the small electrodes and large electrode function together during stimulation as a single electrode. 
     
     
         3 . The system of  claim 1 , wherein the system is configured for spinal cord stimulation. 
     
     
         4 . The system of  claim 1 , wherein the first pair of small electrodes is distal or proximal of the large electrode. 
     
     
         5 . The system of  claim 1 , wherein the electrode array further comprises a second pair of small electrodes and the sensing module includes a first sensing amplifier and a second sensing amplifier, wherein, when the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are electrically coupled across the first sensing amplifier and the second pair of small electrodes are electrically coupled across the second sensing amplifier and in electrical communication with the pace circuit. 
     
     
         6 . The system of  claim 1 , wherein the first pair of small electrodes and the large electrode are each ring electrodes on a tubular body of the lead. 
     
     
         7 . The system of  claim 1 , wherein the first pair of small electrodes and the large electrode are each generally planar electrodes on a paddle of a paddle lead. 
     
     
         8 . The system of  claim 7 , wherein each small electrode of the first pair of small electrodes is segmented into sub-electrodes physically separated from each other by a non-conductive space extending generally parallel to a longitudinal axis of the lead. 
     
     
         9 . The system of  claim 1 , wherein a distal-proximal distance across a non-conductive space between the small electrodes is between approximately 0.05 mm and approximately 2 mm. 
     
     
         10 . The system of  claim 1 , wherein a distal-proximal distance across a non-conductive space between a small electrode and the large electrode is between approximately 0.02 mm and approximately 1 mm. 
     
     
         11 . A spinal cord stimulation system comprising:
 an implantable pulse generator; and   an implantable lead distally extending from the pulse generator and comprising a an electrode array near a distal end of the lead, the electrode array comprising a pair of small electrodes and a large electrode,   wherein the small electrodes are separated from each other by a non-conductive space generally transverse to a longitudinal axis of the lead and having a distal-proximal distance of between approximately 0.05 mm and approximately 2 mm,   wherein the large electrode is separated from a closest of the small electrodes by a non-conductive space generally transverse to a longitudinal axis of the lead and having a distal-proximal distance between approximately 0.02 mm and approximately 1 mm,   wherein the pulse generator causes the small electrodes to both sense and stimulate and the large electrode to only stimulate.   
     
     
         12 . The system of  claim 11 , wherein the small and large electrodes act as a single electrode during stimulation. 
     
     
         13 . The system of  claim 11 , wherein the small electrodes and the large electrode are each ring electrodes on a tubular body of the lead. 
     
     
         14 . The system of  claim 11 , wherein the small electrodes and the large electrode are each generally planar electrodes on a paddle of a paddle lead. 
     
     
         15 . The system of  claim 14 , wherein each small electrode is segmented into sub-electrodes physically separated from each other by a non-conductive space extending generally parallel to a longitudinal axis of the lead. 
     
     
         16 . The system of  claim 11 , wherein the distal-proximal distance across the non-conductive space between the small electrodes is approximately 0.2 mm. 
     
     
         17 . The system of  claim 11 , wherein the distal-proximal distance across the non-conductive space between the small electrode and the large electrode is approximately 0.1 mm. 
     
     
         18 . A spinal cord stimulation system comprising a lead supported electrode array and a pulse generator in electrical communication with the electrode array, wherein the electrode array comprises a first pair of small electrodes and a large electrode, the first pair of small electrodes acting as both sensing electrodes and stimulation electrodes, the large electrode only acting as a stimulation electrode. 
     
     
         19 . The system of  claim 18 , wherein the small electrodes and large electrode act as a single electrode when stimulating. 
     
     
         20 . The system of  claim 19 , wherein, when the small electrodes and large electrodes act as a single electrode when stimulating, the small electrodes and large electrode stimulate at exactly the same instance. 
     
     
         21 . The system of  claim 19 , wherein, when the small electrodes and large electrodes act as a single electrode when stimulating, the small electrodes and large electrode stimulate in at least one of the following ways: a) the stimulating is staggered across the small and large electrodes; or b) the stimulating is staged across the small and large electrodes. 
     
     
         22 . The system of  claim 19 , wherein, when the small electrodes and large electrodes act as a single electrode when stimulating, the small electrodes and large electrode stimulate such that the stimulating occurs in different patterns across the small and large electrodes. 
     
     
         23 . The system of  claim 22 , wherein, when the stimulating occurs in different patterns across the small and large electrodes, the stimulating occurs in at least one of the following patterns: a) distal to proximal in order; b) proximal to distal in order; or a most distal electrode followed by a most proximal electrode. 
     
     
         24 . The system of  claim 19 , wherein, when the small electrodes and large electrodes act as a single electrode when stimulating, the small electrodes and large electrode stimulate exactly same with respect to at least one of voltage or current. 
     
     
         25 . The system of  claim 19 , wherein, when the small electrodes and large electrodes act as a single electrode when stimulating, the small electrodes and large electrode stimulate differently with respect to at least one of voltage or current. 
     
     
         26 . The system of  claim 18 , wherein the small electrodes are separated from each other by a non-conductive space generally transverse to a longitudinal axis of the lead and having a distal-proximal distance of between approximately 0.05 mm and approximately 2 mm. 
     
     
         27 . The system of  claim 18 , wherein the large electrode is separated from a closest of the small electrodes by a non-conductive space generally transverse to a longitudinal axis of the lead and having a distal-proximal distance between approximately 0.02 mm and approximately 1 mm. 
     
     
         28 . The system of  claim 18 , wherein the small electrodes and the large electrode are each ring electrodes on a tubular body of the lead, or the small electrodes and the large electrode are each generally planar electrodes on a paddle of a paddle lead.