Abstract: A technique for protecting an implantable drug administration device from damage caused by over filling. The protection is implemented using an automatic valve positioned between the puncturable sealing septum and the reservoir. This automatic valve is operated volumetrically by coupling the valve actuator to the diaphragm which separates the drug chamber from the fluid volume compensation chamber. When the diaphragm flexes to the maximum fill position, the valve actuator closes the automatic valve, thus prohibiting any further transfer to the reservoir.

Abstract: An implantable electrode system for establishing electrical contact with nerve tissue. The outer substrate of the electrode is a semi-rigid, body compatible, insulating material such as a chronically implantable polymer. The outer substrate is molded as a single structure having a central spine along the longitudinal axis of the electrode. A plurality of fingers extend orthogonally from the central spine, and are bent circularly about a radius of curvature approximating that of the nerve to be contacted. The fingers of the electrode are spread by the retractable channel of the insertion tool during the implant procedure. The retractable channel is placed over the selected nerve and a retraction knob on the handle of the insertion tool is moved in a proximal direction causing the electrode to be ejected on to the nerve. The handle of the insertion tool is curved to require a minimum of exposure of the nerve tissue.

Abstract: An insulated electrical lead for coupling the output of a neurological stimulator with the tissue to be stimulated. In most situations, the neurological stimulator is an implantable pulse generator and the tissue to be stimulated is the spinal cord, although other configurations are contemplated. The insulated electrical lead has a sealable connector at the proximal end which couples to the implantable pulse generator. The distal end contains a number of electrodes placed in close proximity to the tissue to be stimulated. A different conductor couples each of the electrodes to the proximal connector. The distal portion of the insulated lead has a deformable sigmoidal shape. The electrodes are spaced along the length of the deformable sigmoidal shape. This causes the electrodes to be displaced laterally so that specific neural tracts in the spinal cord are preferentially stimulated by various combinations of electrode polarity.

Abstract: An electrode for establishing electrical contact with nerve tissue. The electrode is chronically implantable. The outer substrate of the electrode is a semi-rigid, body compatible, insulating material such as a chronically implatable polymer. The outer substrate is molded as a single structure having a central spine along the longitudinal axis of the electrode. A plurality of fingers extend orthogonally from the central spine, and are bent circularly about a radius of curvature approximating that of the nerve to be contacted. Each of the plurality of fingers is of sufficient length to extend approximately one-half of the distance around the outer circumference of the nerve tissue. The plurality of fingers extend from the central spine in one of two opposite directions causing the electrode structure to encompass a hollow cylinder having an inside diameter the same as the nerve.

Abstract: An improved electrode for establishing electrical contact with a nerve of a patient. This electrical contact may be used to sense neural activity on the nerve or to artificially stimulate it to perform various medical treatments. The electrode has an outer cuff of an insulating material which is sutured around the nerve to be contacted. A drug impregnated layer of material is positioned inside of the outer cuff. This material is a polymeric matrix which permits the drug to leach out at a predetermined rate. The drug is a steroid such as dexamethasone sodium phosphate. The actual electrical contact is produced by metallic foil which is positioned on the surface of the drug impregnated layer of material which is located inside of the cuff. An insulated lead electrically couples the metallic foil to an electronic circuit located remote from the nerve. The leaching out of the drug serves to control irritation, swelling, and impedance of the nerve/electrode interface.