Flexible electrode
View Patent ↗An electrode array has a flexible body supporting a plurality of electrodes. Each electrode comprises an exposed connector pad at the upper end of the body, an exposed recording/stimulating pad at the lower end of the body, and a conductor located within the body and electrically connecting the connector pad and the recording/stimulating pad. In one embodiment the electrode array has an elongated recording/stimulating portion coiled or folded to distribute the exposed recording/stimulating pads in three dimensions. An implantation method employs an introducer with a helical portion to which an end of the flexible electrode is attached. The helical portion straightens to pass through a small-diameter cannula and then resumes its helical configuration to place the recording/stimulating portion of the attached electrode in a helix within the patient's tissues.
1. An apparatus comprising:
A flexible electrode body having an upper end an opposed lower end and defining a first opening and a second opening;
a shaped deformable introducer wire having an upper portion and an opposed lower portion, wherein the upper portion of the introducer wire is substantially straight and the lower portion of the introducer wire is configured as a helix, and wherein the electrode body has a relaxed configuration and is resiliently deformable to pass through a cannula and at least partially resume the relaxed configuration when placed within a patient's tissue;
a means for removably attaching the electrode to the introducer wire such that the introducer wire can embed the flexible electrode body in a three-dimensional configuration within the patient's tissue and can then be removed from the patient's tissue, leaving the electrode body in situ; and
at least one electrode, wherein the electrode comprises:
an electrode pad at the lower end of the electrode body,
a connector pad at the upper end of the electrode body, and
a conductor directly electrically connecting said electrode pad and said conductor pad, said conductor pad being enclosed within said body;
wherein the first opening body in said electrode body is positioned in registry with said electrode pad so as to expose said electrode pad to the patient's tissue, and wherein the second opening in said electrode body is positioned in registry with said connector pad so as to expose said connector pad for connection to external electronics.
2. The apparatus of claim 1 , wherein said electrode body comprises a first flexible sheet in contact with a second flexible sheet.
3. The apparatus of claim 2 , wherein at least one of the first sheet and the second sheet comprises polyimide.
4. The apparatus of claim 2 , wherein said conductor is interposed between portions of said first and second flexible sheets and wherein said conductor is encapsulated by the respective first and second flexible sheets.
5. The apparatus of claim 4 , wherein said electrode body has a cross-sectional thickness of from approximately 1 micron to approximately 10 microns.
6. The apparatus of claim 1 , wherein at least a portion of the electrode body has a helical shape.
7. The apparatus of claim 1 , wherein the at least one electrode comprises a first electrode and a second electrode.
8. The apparatus of claim 1 , wherein the at least one electrode comprises a plurality of electrodes.