# US 8,771,238 B2 · Injection device comprising an optical sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,238 B2 - Document ID: US8771238B2 - Status: Granted - Kind: B2 - Application number: 13/461,415 - Filed: 2012-05-01 - Published: 2012-08-23 - Granted: 2014-07-08 - Earliest claimed: 2005-05-10 - Assignees: Novo Nordisk A/S - Applicants: Preben Mikael Nielsen; Bodo Von Munchow; Carsten Bitsch Pedersen; Per Molgaard Pedersen - Inventors: Preben Mikael Nielsen; Bodo Von Munchow; Carsten Bitsch Pedersen; Per Molgaard Pedersen - Web page: https://patentgrep.com/patent/US8771238B2 ## CPC - A61M 5/31525: {Dosing (burettes, pipettes B01L3/02)} - A61M 5/3155: {by rotational movement of dose setting member, e.g. during setting or filling of a syringe} - A61M 5/31556: {Accuracy improving means} - A61M 5/31568: {Means keeping track of the total dose administered, e.g. since the cartridge was inserted} - A61M 2205/3306: Optical measuring means - A61M 2205/6063: Optical identification systems - G01D 5/3473: {Circular or rotary encoders} - G01D 5/34792: {with only digital scales or both digital and incremental scales} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract The present invention relates to an injection device comprising an optically-based sensor for determining the position or setting of a dose setting member arranged to set a dose to be injected from the injection device. In particular, the present invention relates to an injection device comprising a rotatably mounted member having a plurality of optically coded paths arranged on an outer surface thereof. The rotatably mounted member is operatively connected to the dose setting member and is adapted to rotate with the dose setting member. ## Claims ### Claim 1 An arrangement for determining the position of a dose setting member adapted to set a dose of a medicament to be injected from an injection device, the arrangement comprising: a rotatably mounted member having a plurality of optically coded tracks arranged on an outer surface thereof adapted to set a dose of medicament to be injected from an injection device, a plurality of light generators each for generating a beam of light towards the rotatably mounted member, structure for guiding light beams from the plurality of light generators to the rotatably mounted member and structure for guiding light beams from the rotatably mounted member to a plurality of light sensitive elements or areas, a control circuit coupled to the plurality of light sensitive elements or areas to determine the position of the rotatably mounted member relative to the plurality of light sensitive elements or areas, and whereby the arrangement is structured to determine the position of a dose setting member relative to the plurality of light sensitive elements or areas. ### Claim 2 (depends on 1) The arrangement according to claim 1, wherein the structure for guiding light beams illuminate different areas of the optically coded tracks. ### Claim 3 (depends on 1) The arrangement according to any of claim 1, wherein six optically coded tracks paths are arranged on the outer surface of the rotatably mounted member. ### Claim 4 (depends on 1) The arrangement according to claim 1, wherein the optically coded tracks are provided by varying the optical properties along said tracks. ### Claim 5 (depends on 4) The arrangement according to claim 4, wherein the optical properties along the tracks paths are varied by varying an optical reflectivity or transparency of the outer surface of the rotatably mounted member. ### Claim 6 (depends on 1) The arrangement according to claim 1, wherein the rotatably mounted member is at least partly transparent. ### Claim 7 (depends on 6) The arrangement according to claim 6, further comprising a light emitter adapted to couple a beam of light into the rotatably mounted member. ### Claim 8 (depends on 7) The arrangement according to claim 7, further comprising a light detecting structure having a plurality of light sensitive areas, the light detecting structure being arranged to detect light escaping the outer surface of the rotatably mounted member. ### Claim 9 (depends on 8) The arrangement according to claim 8, wherein the number of light sensitive areas equals the number of optically coded tracks. ### Claim 10 (depends on 1) The arrangement according to claim 1, further comprising structure for guiding a plurality of guided light beams, each light beam being guided so as to be incident on one optically coded track path. ### Claim 11 (depends on 10) The arrangement according to claim 10, wherein the number of guided light beams equals the number of optically coded tracks paths. ### Claim 12 (depends on 10) The arrangement according to claim 10, further comprising a light detector, the light detector comprising a plurality of light sensitive elements. ### Claim 13 (depends on 12) The arrangement according to claim 12, wherein the number of light sensitive elements equals the number of optically coded tracks. ### Claim 14 (depends on 12) The arrangement according to claim 12, further comprising structure for guiding a plurality of light beams reflected from the optically coded tracks to the light-sensitive elements. ### Claim 15 (depends on 10) The arrangement according to claim 10, wherein the light guiding structure arranged to provide light beams to and from the optically coded tracks are arranged as through-going openings in a housing. ### Claim 16 (depends on 15) The arrangement according to claim 15, wherein the light guiding structure for guiding light to the optically coded tracks are arranged so that the light beams are incident onto the optically coded tracks in the range of 40-50 degrees. ### Claim 17 (depends on 15) The arrangement according to claim 15, wherein the light guiding structure for guiding light from the optically coded tracks-to the light sensitive elements are arranged so that the light beams leave the optically coded tracks in the range of 40-50 degrees. ### Claim 18 An arrangement for determining an amount of a medicament injected from an injection device, the arrangement comprising: a rotatably mounted member having a plurality of optically coded tracks arranged on an outer surface thereof, a plurality of light generators each for generating a beam of light towards the rotatably mounted member, structure for guiding light beams from the plurality of light generators to the rotatably mounted member and structure for guiding light beams from the rotatably mounted member to a plurality of light sensitive elements or areas, a control circuit coupled to the plurality of light sensitive elements or areas to determine the position of the rotatably mounted member relative to the plurality of light sensitive elements or areas, and whereby the arrangement is structured to determine an amount of a medicament injected from an injection device. ### Claim 19 (depends on 18) The arrangement according to claim 18, wherein the structure for guiding light beams illuminate different areas of the optically coded tracks. ### Claim 20 (depends on 18) The arrangement according to any of claim 18, wherein six optically coded tracks are arranged on the outer surface of the rotatably mounted member. ### Claim 21 (depends on 18) The arrangement according to claim 18, wherein the optically coded tracks are provided by varying the optical properties along said tracks. ### Claim 22 (depends on 21) The arrangement according to claim 21, wherein the optical properties along the tracks are varied by varying an optical reflectivity or transparency of the outer surface of the rotatably mounted member. ### Claim 23 (depends on 18) The arrangement according to claim 18, wherein the rotatably mounted member is at least partly transparent. ### Claim 24 (depends on 23) The arrangement according to claim 23, further comprising a light emitter adapted to couple a beam of light into the rotatably mounted member. ### Claim 25 (depends on 24) The arrangement according to claim 24, further comprising a light detecting structure having a plurality of light sensitive areas, the light detecting structure being arranged to detect light escaping the outer surface of the rotatably mounted member. ### Claim 26 (depends on 25) The arrangement according to claim 25, wherein the number of light sensitive areas equals the number of optically coded tracks. ### Claim 27 (depends on 18) The arrangement according to claim 18, further comprising structure for guiding a plurality of guided light beams, each light beam being guided so as to be incident on one optically coded path. ### Claim 28 (depends on 27) The arrangement according to claim 27, wherein the number of guided light beams equals the number of optically coded tracks. ### Claim 29 (depends on 27) The arrangement according to claim 27, further comprising a light detector, the light detector comprising a plurality of light sensitive elements. ### Claim 30 (depends on 29) The arrangement according to claim 29, wherein the number of light sensitive elements equals the number of optically coded tracks. ### Claim 31 (depends on 29) The arrangement according to claim 29, further comprising structure for guiding a plurality of light beams reflected from the optically coded tracks to the light sensitive elements. ### Claim 32 (depends on 27) The arrangement according to claim 27, wherein the light guiding structure arranged to provide light beams to and from the optically coded tracks are arranged as through-going openings in a housing. ### Claim 33 (depends on 32) The arrangement according to claim 32, wherein the light guiding structure for guiding light to the optically coded tracks are arranged so that the light beams are incident onto the optically coded tracks in the range of 40-50 degrees. ### Claim 34 (depends on 32) The arrangement according to claim 32, wherein the light guiding structure for guiding light from the optically coded tracks to the light sensitive elements are arranged so that the light beams leave the optically coded tracks in the range of 40-50 degrees.