Electrode configuration for an implantable electroacupuncture device

A self-contained implantable electroacupuncture device (IEAD) for treating a specified medical condition of a patient through application of electroacupuncture (EA) stimulation pulses applied substantially at or near a specified acupoint, comprising:

• a rigid, coin-shaped housing having a thickness of no greater than about 2.5 mm and a diameter no greater than about 25 mm;
• at least one cathodic electrode and at least one anodic electrode formed in a prescribed configuration as an integral part of at least one outside surface of the housing;
• stimulation circuitry residing inside the housing and electrically coupled to the at least one cathodic and at least one anodic electrodes, wherein the stimulation circuitry generates EA stimulation pulses that are delivered to body tissue through the at least one cathodic and at least one anodic electrodes in accordance with a prescribed stimulation regimen, wherein said stimulation regimen defines the duration and rate at which a stimulation session is applied to the patient, said stimulation regimen requiring that the stimulation session have a duration of T3 minutes, wherein T3 is at least 10 minutes, and a rate of occurrence of once every T4 minutes, wherein the ratio of T3/T4 is no greater than 0.05, and wherein during each stimulation session EA stimulation pulses having one or more specified widths and amplitudes are generated at one or more specified rates;
• and
• a coin-cell type primary battery residing inside the housing that provides the operating power for the stimulation circuitry, wherein the primary battery has an internal impedance that is greater than 5 ohms;
• wherein the IEAD is leadless and the IEAD housing is hermetically-sealed, and the coin-cell primary battery has sufficient capacity to power the operation of the IEAD in accordance with the prescribed stimulation regimen for at least two years without any further action needed on the part of the patient or other medical personnel;
• and
• wherein the at least one cathodic electrode is located on a top or bottom surface of the housing and positioned no closer than 5 mm from the closest edge of the nearest at least one anodic electrode, wherein at least one of the cathodic or anodic electrodes comprises an annular or circumscribing electrode that surrounds or encompasses the other at least one cathodic or anodic electrodes, and wherein the total surface area of the at least one cathodic electrode is no smaller than about 0.5 mm2, and wherein the positioning and surface area of the at least one cathodic electrode is selected to allow a desired current density to flow through the electrode surface area without causing electrode corrosion or current shunting.