Electrode
A device, system and method for the delivery of electrical stimulation for the treatment of acute or chronic pain and/or for the improvement of body function. There is described a neuromodulation electrode device including a substrate having a skin-facing surface and an electrode having at least one convex active surface projecting from the skin-facing surface of substrate for applying an electrical stimulation signal. A conductive gel layer having an electrode portion overlies the convex active surface(s) of the electrode. The substrate is formed of a conductive gel or the conductive gel layer further includes a substrate portion overlying the skin-facing surface of the substrate. The device further includes an isolating frame surrounding the perimeter of the electrode to provide electrical isolation between the electrode and the conductive gel substrate or from the substrate portion of the conductive gel layer.
1 . A neuromodulation electrode device comprising:
a substrate having a skin-facing surface;
an electrode having at least one convex active surface projecting from the skin-facing surface of substrate for applying an electrical stimulation signal; and
a conductive gel layer having an electrode portion overlying the convex active surface(s) of the electrode;
wherein the substrate is formed of a conductive gel or the conductive gel layer further comprises a substrate portion overlying and in contact with the skin-facing surface of the substrate and surrounding the electrode; and
wherein the device further comprises an isolating frame extending around the perimeter of the electrode when viewed in a direction perpendicular to the skin-facing surface, wherein:
the isolating frame is between the electrode and the substrate formed of conductive gel when viewed in the direction perpendicular to the skin-facing surface and spaces the electrode apart from the substrate formed of conductive gel such that the electrode is electrically isolated from the substrate formed of the conductive gel, or
the isolating frame is between the electrode and the substrate portion of the conductive gel layer when viewed in the direction perpendicular to the skin-facing surface and spaces the electrode apart from the substrate portion of the conductive gel layer such that the electrode is electrically isolated from the substrate portion of the conductive gel layer.
2 . The device according to claim 1 wherein the substrate is formed of conductive gel and further comprises a backing layer formed on the surface of the conductive gel substrate opposing the skin-facing surface.
3 . The device of claim 1 wherein the substrate is formed of a non-gel material and the conductive gel layer further comprises a substrate portion that overlies the substrate.
4 . The device of claim 3 wherein the electrode portion and substrate portion of the conductive gel layer are of uniform thickness.
5 . The device of claim 2 wherein the backing layer is formed of a self-supporting, pliable material, or wherein the substrate is formed of a non-gel material which is a self-supporting, pliable material.
6 . The device of claim 2 wherein the backing layer is formed of a thermos-formable or curable material, or wherein the substrate is formed of a non-gel material which is a thermo-formable or curable material.
7 . The device of claim 1 wherein the skin-facing surface of the substrate or the substrate portion of the conductive gel layer is adhesive.
8 . The device of claim 1 wherein the isolating frame has a width of between 2 and 20 mm.
9 . The device of claim 1 wherein the isolating frame is an isolating annulus comprising an isolating ring formed of a non-conductive material or an isolating gap.
10 . The device of claim 1 wherein the electrode has a single hemispherical stimulating surface with a circular cross-section.
11 . The device of claim 10 wherein the diameter of the electrode is between 2 and 12 mm.
12 . The device of claim 1 wherein the convex stimulating surface of the electrode projects between 3 to 6 mm beyond the skin-facing surface of the substrate.
13 . The device of claim 1 wherein the device comprises a plurality of electrodes mounted in an array or matrix on the substrate, each of the plurality of electrodes having a respective isolating frame.
14 . The device of claim 1 wherein the conductive gel layer or the conductive gel substrate is formed of a conductive hydrogel.
15 . A device of claim 1 wherein each of the electrodes and the conductive gel substrate/substrate portion of the conductive gel layer comprises a respective electrically conducting leads for connection to a power source so as to impart a first polarity to the electrode(s) and a second opposite polarity to the conductive gel substrate/substrate portion of the conductive gel layer.
16 . A neuromodulation system comprising one or more neuromodulation electrode devices of claim 1 and an external electric power supply.
17 . The system according to claim 16 wherein the electric power supply is adapted to generate a stimulating signal having a frequency of from 1 Hz to 10 kH and a current of up to 40 mA.
18 . A method for treating chronic or acute pain and/or improving body function comprising application of one or more neuromodulation electrode devices according to claim 1 to an area affected by the pain, and applying a stimulating signal in the range 1 to 10,000 Hz.
19 . The device according to claim 1 wherein the electrode portion of the conductive gel layer includes a concave surface facing the electrode and receiving the electrode therein and a convex surface opposing the concave surface and projecting from the substrate formed of the conductive gel or the substrate portion of the conductive gel layer.