Systems and methods for delivering electric current for spinal cord stimulation

Abstract

Various system embodiments comprise a lead having a distal end and a proximal end. The distal end includes a plurality of electrodes. The lead is configured to be fed into a dorsal epidural space of a human to a desired region of a spinal column and to be fed laterally to at least partially encircle a spinal cord in the desired region to place at least one stimulation electrode in position to stimulate a dorsal nerve root and at least another stimulation electrode in position to stimulate a ventral nerve root. The desired region may include cervical vertebrae, thoracic vertebrae, or lumbar vertebrae. Some embodiments stimulate the spinal cord in the T1-T5 region.

We claim: 
     
         1 . A system comprising:
 a lead having a distal end and a proximal end including a plurality of electrodes, the lead being configured to steer into a dorsal epidural space of a human to a desired region of a spinal column and to at least partially encircle a spinal cord in the desired region to place at least one stimulation electrode of the plurality of electrodes in position to stimulate at least one of a dorsal nerve root and a ventral nerve root; and   a device coupled to the proximal end of the lead and configured to deliver stimulation pulses to stimulate at least one of the dorsal nerve root and the ventral nerve root.   
     
     
         2 . The system of  claim 1 , wherein the lead is a steerable stimulation lead configured to steer into a dorsal epidural space of a human to a desired region of a spinal column and to at least partially encircle a spinal cord in the desired region to place at least one stimulation electrode of the plurality of electrodes in position to stimulate at least one of a dorsal nerve root and a ventral nerve root. 
     
     
         3 . The system of  claim 2 , wherein the steerable stimulation lead comprises a pre-formed shape and comprises a shape memory material. 
     
     
         4 . The system of  claim 3 , further comprising a delivery catheter configured to deploy the steerable stimulation lead at the desired region, and wherein the steerable stimulation lead is configured to bias to the pre-formed shape after deployment from the delivery catheter. 
     
     
         5 . The system of  claim 2 , wherein the steerable stimulation lead is steerable in at least two directions. 
     
     
         6 . The system of  claim 2 , wherein the steerable stimulation lead comprises a lumen, and the lumen is configured to receive a steering tendon. 
     
     
         7 . The system of  claim 6 , further comprising the steering tendon, and wherein steerable stimulation lead is configured to steer the steerable stimulation lead. 
     
     
         8 . The system of  claim 1 , further comprising a steerable delivery catheter, and wherein the lead is configured to steer via the steerable delivery catheter. 
     
     
         9 . The system of  claim 8 , wherein the steerable delivery catheter is configured to deploy the lead at the desired region. 
     
     
         10 . The system of  claim 8 , wherein the steerable delivery catheter comprises a deflection area, a first steering tendon, a second steering tendon, a first anchor member, and a second anchor member, wherein the first steering tendon is attached to the first anchor member located at a distal portion of a distal end of the lead, and the second steering tendon is attached to the second anchor member located distal to the deflection area. 
     
     
         11 . The system of  claim 8 , wherein the steerable delivery catheter is steerable in at least two directions. 
     
     
         12 . A system comprising:
 a steerable lead having a distal end and a proximal end including a plurality of electrodes, the steerable stimulation lead having a pre-formed shape and being configured to steer into a dorsal epidural space of a human to a desired region of a spinal column and to at least partially encircle a spinal cord in the desired region to place at least one stimulation electrode of the plurality of electrodes in position to stimulate at least one of a dorsal nerve root and a ventral nerve root; and   a device coupled to the proximal end of the lead and configured to deliver stimulation pulses to stimulate at least one of the dorsal nerve root and the ventral nerve root.   
     
     
         13 . The system of  claim 12 , wherein the plurality of electrodes are configured to direct a directional stimulation field toward at least one of a dorsal nerve root and a ventral nerve root. 
     
     
         14 . The system of  claim 12 , further comprising a steerable delivery catheter, and wherein the steerable lead is configured to steer via the steerable delivery catheter. 
     
     
         15 . The system of  claim 14 , wherein the steerable delivery catheter is configured to deploy the steerable stimulation lead at the desired region. 
     
     
         16 . The system of  claim 12 , wherein the steerable lead comprises a distal tip, and the distal tip is biased to wrap around and maintain contact with the spinal column. 
     
     
         17 . A method for implanting a spinal cord stimulation lead, comprising:
 introducing the lead into a dorsal epidural space;   feeding the lead through the dorsal epidural space proximate to a desired vertebra;   steering at least one electrode operationally proximate to at least one of a dorsal nerve root to capture a portion of a dorsal nerve root with electrical stimulation delivered using the at least one electrode; and   steering at least another electrode operationally proximate to the ventral nerve root to capture at least a portion of a ventral nerve root with electrical stimulation delivered using the at least another electrode.   
     
     
         18 . The method of  claim 16 , wherein the lead comprises a distal end made with a material having shape memory comprising a predetermined shape. 
     
     
         19 . The method of  claim 18 , further comprising passing the distal end proximate to the dorsal nerve root and the ventral nerve root when the distal end is in a flexed position; and setting the position of the lead includes relaxing the distal end to allow the distal end to at least partially surround the spinal cord. 
     
     
         20 . The method of  claim 17 , further comprising feeding a steerable catheter through the dorsal epidural space and laterally past the desired vertebra and the dorsal nerve root to deliver the lead to the desired vertebra.