# US 7,610,098 B2 · Charge-integrating retinal prosthesis and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,098 B2 - Document ID: US7610098B2 - Status: Granted - Kind: B2 - Application number: 11/313,245 - Filed: 2005-12-20 - Published: 2007-06-21 - Granted: 2009-10-27 - Earliest claimed: 2005-12-20 - Assignees: IMI Intelligent Medical Implants AG - Inventors: George Y. McLean - Web page: https://patentgrep.com/patent/US7610098B2 ## CPC - A61F 2/14: Eye parts, e.g. lenses or corneal implants; Artificial eyes - A61F 2/1694: {Capsular bag spreaders therefor} - A61F 9/007: Methods or devices for eye surgery - A61N 1/36046: {of the eye} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract A retinal prosthesis that provides power control capabilities through the temporal integration of electrical charge is provided. The retinal prosthesis comprises at least one stimulating component, each stimulating component in turn comprising a photojunction element (e.g., a photodiode) in electrical communication with an electrode. A pulse generation circuit provides a reverse-bias signal and, from time to time, a pulsatile forward-bias signal to the photojunction element. During application of the reverse-bias signal, light incident upon the photojunction element causes electrical charge to be accumulated. Upon application of the pulsatile forward-bias signal, the accumulated electrical charge is injected via the electrode into retinal tissues, thereby stimulating the retina. By appropriately selecting the bias signal parameters, a sufficient amount of charge may be accumulated to ensure reaching stimulation thresholds. In this manner, control over stimulus currents may be improved while still retaining advantageous use of the eye's natural focusing and imaging capabilities. ## Claims ### Claim 1 A retinal prosthesis for stimulating a retina of an eye, comprising: at least one stimulating component, each stimulating component comprising: a photojunction element; and an electrode for electrical contact with tissues of the retina, the electrode being in electrical communication with the photojunction element via a first terminal of the photojunction element; and a pulse generation circuit, in electrical communication with a second terminal of the photojunction element, which provides a reverse-bias signal to the at least one photojunction element and which, from time to time, provides a pulsatile forward-bias signal to the at least one photojunction element, wherein the pulsatile forward-bias signal releases accumulated electrical charge into retinal tissues via said electrode to stimulate the retina. ### Claim 2 (depends on 1) The retinal prosthesis of claim 1, further comprising: an energy source in electrical communication with and providing power to the pulse generation circuit. ### Claim 3 (depends on 2) The retinal prosthesis of claim 2, the energy source further comprising a photovoltaic device. ### Claim 4 (depends on 3) The retinal prosthesis of claim 3, the photovoltaic device configured for intraocular implantation. ### Claim 5 (depends on 2) The retinal prosthesis of claim 2, the energy source further comprising a secondary inductive coil. ### Claim 6 (depends on 1) The retinal prosthesis of claim 1, further comprising: a plurality of stimulating components; and a common electrode in electrical communication with the pulse generation circuit and in electrical communication with the second terminal of each photojunction element of the plurality of stimulating components. ### Claim 7 (depends on 6) The retinal prosthesis of claim 6, further comprising: an insulating layer disposed over the common electrode to electrically insulate the common electrode from an environment surrounding the retinal prosthesis. ### Claim 8 (depends on 6) The retinal prosthesis of claim 6, wherein the pulse generation circuit comprises an extra-ocular pulse generation circuit, and further comprising: a conductive element, in electrical communication with the extra-ocular pulse generation circuit and the common electrode, for conveying the reverse-bias signal and the pulsatile forward-bias signal. ### Claim 9 (depends on 1) The retinal prosthesis of claim 1, wherein the photojunction element of each of the at least one stimulating component further comprises a photodiode. ### Claim 10 (depends on 1) The retinal prosthesis of claim 1, wherein the electrode of each of the at least one stimulating component is configured for implantation proximate to the retina. ### Claim 11 (depends on 1) The retinal prosthesis of claim 1, wherein the electrode of each of the at least one stimulating component further comprises an iridium oxide electrode. ### Claim 12 A retinal prosthesis for stimulating a retina of an eye, comprising: a plurality of photodiodes; a plurality of iridium oxide electrodes, configured for implantation proximate to the retina, each in electrical communication with, via a first terminal of, a uniquely corresponding one of the plurality of photodiodes; a common electrode in electrical communication with a second terminal of each of the plurality of photodiodes; and a pulse generation circuit, in electrical communication with the common electrode, which provides a reverse-bias signal to the plurality of photodiodes and which, from time to time, provides a pulsatile forward-bias signal to the plurality of photodiodes to release accumulated electrical charge into retinal tissues via said plurality of iridium oxide electrodes to stimulate the retina. ### Claim 13 (depends on 12) The retinal prosthesis of claim 12, further comprising: an energy source in electrical communication with and providing power to the pulse generation circuit. ### Claim 14 (depends on 13) The retinal prosthesis of claim 13, the energy source further comprising a photovoltaic device. ### Claim 15 (depends on 13) The retinal prosthesis of claim 13, the energy source further comprising a secondary inductive coil. ### Claim 16 (depends on 12) The retinal prosthesis of claim 12, further comprising: an insulating layer disposed over the common electrode to electrically insulate the common electrode from an environment surrounding the retinal prosthesis. ### Claim 17 A method for stimulating a retina of an eye in which a retinal prosthesis comprising a photojunction element has been implanted proximate to the retina, the retinal prosthesis further comprising an electrode in electrical communication with a first terminal of the photojunction element, the method comprising: applying a reverse-bias signal to the photojunction element; while the reverse-bias signal is applied to the photojunction element, accumulating electrical charge through photoconduction resulting from light incident upon the photojunction element; and from time to time, applying a pulsatile forward-bias signal to the photojunction element to establish electrical continuity in the photojunction, and thereby to inject the electrical charge into the retina via the electrode to provide a stimulus current. ### Claim 18 (depends on 17) The method of claim 17, further comprising: controlling amplitude of the stimulus current by varying the duration of the reverse-bias signal. ### Claim 19 (depends on 17) The method of claim 17, further comprising: controlling amplitude of the stimulus current by varying an amplitude of the pulsatile forward-bias signal. ### Claim 20 (depends on 17) The method of claim 17, further comprising: applying light, beyond ambient light, to the photojunction element. ### Claim 21 (depends on 20) The method of claim 20, further comprising applying infrared light to the photojunction element.