# US 10,117,610 B2 · Method for spectrophotometric blood oxygenation monitoring > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,117,610 B2 - Document ID: US10117610B2 - Status: Granted - Kind: B2 - Application number: 15/283,883 - Filed: 2016-10-03 - Published: 2017-03-30 - Granted: 2018-11-06 - Earliest claimed: 2005-05-12 - Assignees: CAS Medical Systems, Inc. - Applicants: CAS Medical Systems, Inc. - Inventors: Paul B. Benni - Web page: https://patentgrep.com/patent/US10117610B2 ## CPC - A61B 5/14551: {for measuring blood gases} - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/0261: {using optical means, e.g. infrared light} - A61B 5/14546: {for measuring analytes not otherwise provided for, e.g. ions, cytochromes} - A61B 5/14552: {Details of sensors specially adapted therefor} - A61B 5/14553: {specially adapted for cerebral tissue} - A61B 5/1495: Calibrating or testing of in-vivo probes - A61B 5/6814: {Head} - G01N 21/359: using near infrared light - G01N 21/49: within a body or fluid - G01N 2021/3144: {for oxymetry} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract According to the present invention, a method and apparatus for non-invasively determining the blood oxygen saturation level within a subject's tissue is provided. The method comprises the steps of: a) providing a spectrophotometric sensor operable to transmit light into the subject's tissue, and to sense the light; b) detecting light after passage through the subject's tissue using the sensor, and producing initial signal data from the light sensed; c) calibrating the sensor to that particular subject using the initial signal data, thereby accounting for the specific physical characteristics of the particular subject's tissue being sensed; and d) using the calibrated sensor to determine the blood oxygen parameter value within the subject's tissue. ## Claims ### Claim 1 A method for non-invasively determining a blood oxygen parameter value of a subject's tissue, comprising: providing a spectrophotometric sensor having one or more transducers and a processor portion, each transducer including at least one light source and at least one light detector, and the processor portion including at least one processor; using the at least one processor to execute algorithmic instructions stored in a memory device, which instructions cause the at least one processor to: control the at least one light source to transmit light at one or more wavelengths of red light into the subject's tissue; control the at least one light detector to sense the transmitted red light after passage through the subject's tissue and produce initial signals representative of the sensed red light; receive and process the initial signals from the at least one light detector and produce first signal data from the initial signals; selectively alter the algorithmic instructions using the first signal data to account for the specific physical characteristics of the particular subject's tissue being sensed; and determine the blood oxygen parameter value within the subject's tissue using the selectively altered algorithmic instructions. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more wavelengths of red light include light wavelengths in the range of about 622 nm to 780 nm. ### Claim 3 (depends on 2) The method of claim 2, wherein the one or more wavelengths of red light include visible light wavelengths in the range of about 622 nm to 700 nm. ### Claim 4 (depends on 3) The method of claim 3, wherein the one or more wavelengths of red light include light at the wavelength of about 690 nm. ### Claim 5 (depends on 1) The method of claim 1, wherein the blood oxygen parameter value within the subject's tissue is determined using signals representative of light sensed by the at least one light detector subsequent to the sensing of the light used to produce the initial signals. ### Claim 6 (depends on 1) The method of claim 1, wherein the first signal data is attributable to non-pulsatile blood flow within the subject's tissue. ### Claim 7 (depends on 1) The method of claim 1, wherein the blood oxygen parameter is oxyhemoglobin. ### Claim 8 (depends on 1) The method of claim 1, wherein the blood oxygen parameter is deoxyhemoglobin. ### Claim 9 An apparatus for non-invasively determining a blood oxygen parameter value of a subject's tissue, comprising: at least one transducer having at least one light source and at least one light detector, wherein the transducer is configured to be applied to a tissue surface of the subject with the at least one light source positioned to transmit light into the subject's tissue and the at least one light detector positioned to sense the transmitted light after passage through the subject's tissue; and a processor portion having at least one processor in communication with a memory device storing algorithmic instructions, which instructions cause the at least one processor to selectively: control the at least one light source to transmit light at one or more wavelengths of red light into the subject's tissue; control the at least one light detector to sense the transmitted red light after passage through the subject's tissue and produce initial signals representative of the sensed red light; receive and process the initial signals from the at least one light detector and produce first signal data from the initial signals; alter the algorithmic instructions using the first signal data to account for the specific physical characteristics of the particular subject's tissue being sensed; and determine the blood oxygen parameter value within the subject's tissue using the selectively altered algorithmic instructions. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the one or more wavelengths of red light include light wavelengths in the range of about 622 nm to 780 nm. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the one or more wavelengths of red light include visible light wavelengths in the range of about 622 nm to 700 nm. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the one or more wavelengths of red light include light at the wavelength of about 690 nm. ### Claim 13 (depends on 9) The apparatus of claim 9, wherein the blood oxygen parameter value within the subject's tissue is determined using signals representative of light sensed by the at least one light detector subsequent to the sensing of the light used to produce the initial signals. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the blood oxygen parameter is oxyhemoglobin. ### Claim 15 (depends on 9) The method of claim 9, wherein the blood oxygen parameter is deoxyhemoglobin. ### Claim 16 (depends on 9) The apparatus of claim 9, wherein the at least one light source is configured to transmit light along a plurality of wavelengths into the subject's tissue.