Transverse tripole neurostimulation lead, system and method
An implantable neurostimulation lead, method and system adapted for tripolar electric simulation and/or field steering. The neurostimulation lead is are adapted to provide an electrode array defining, for example, a plurality of electrode sets that may be used to provide tripolar stimulation and/or electric field steering.
1. An implantable electrode array adapted for epidural implantation for electrically stimulating the spinal cord, the electrode array comprising first, second and third longitudinally extending columns with each column including a plurality of stimulation electrodes spaced apart and the first and second columns being laterally spaced apart from the third column along opposite sides of the third column, the stimulation electrodes of the first and second columns having substantially similar center-to-center spacing of adjacent electrodes, and the stimulation electrodes of the third column having a center-to-center spacing of adjacent electrodes that is no greater than approximately one half of the center-to-center spacing of adjacent electrodes of the first and second columns, wherein the plurality of stimulation electrodes for the third column includes at least double the number of electrodes for either the first or second columns.
2. The implantable electrode array according to claim 1 in which the plurality of stimulation electrodes for the first and second columns includes the same number of electrodes.
3. The implantable electrode array according to claim 1 in which the stimulation electrodes of the first and second columns have equal longitudinal electrode length and each electrode of the first and second columns overlap laterally with two electrodes of the third column.
4. The implantable electrode array according to claim 1 in which the ratio of the number of stimulation electrodes of the third column relative to the number of electrodes of either the first or second columns is no more than approximately five.
5. The implantable electrode array according to claim 4 in which the ratio of the number of stimulation electrodes of the third column relative to the number of electrodes of either the first or second columns is an integer value.
6. The implantable electrode array according to claim 1 in which the ratio of the number of stimulation electrodes of the third column relative to the number of electrodes of either the first or second columns is an integer value.
7. The implantable electrode array according to claim 1 in which the plurality of electrodes for each of the first and second columns comprises four electrodes, and the plurality of electrodes for the third column comprises eight electrodes.
8. The implantable electrode array according to claim 1 in which each of the first, second and third columns form a generally parallel array.
9. The implantable electrode array of claim 1 further comprising instructions for use of the implantable electrode array, the instructions specifying use of the implantable electrode array consistent with the following steps:
implanting the implantable electrode array in the epidural space of a patient; and
programming the stimulation electrodes to create a tripole in which at least one electrode is active on each of the first, second and third columns.
10. The implantable electrode array of claim 1 further comprising a label or instructions for use with the implantable electrode array, the label or instructions describing use of the implantable electrode array to form a tripole stimulation pattern.