# US 11,998,300 B2 · Optical method for gingivitis detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,998,300 B2 - Document ID: US11998300B2 - Status: Granted - Kind: B2 - Application number: 17/275,216 - Filed: 2019-09-04 - Published: 2022-02-24 - Granted: 2024-06-04 - Earliest claimed: 2018-09-11 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Olaf Thomas Johan Antonie Vermeulen - Web page: https://patentgrep.com/patent/US11998300B2 ## CPC - A61B 5/0088: {for oral or dental tissue} - G01N 21/314: {with comparison of measurements at specific and non-specific wavelengths (dual wavelength spectrometry G01J3/427)} - G01N 21/3151: {using two sources of radiation of different wavelengths (G01N21/33 - G01N21/39 take precedence)} - G01N 21/47: Scattering, i.e. diffuse reflection (G01N21/25, G01N21/41 take precedence {G01N21/55 takes precedence}) - G01N 21/4738: {Diffuse reflection (precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration), e.g. also for testing fluids, fibrous materials} - 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 A tissue inflammation detection system (600) including: a light emitter (602) configured to emit light towards tissue (604); at least one light detector (606) configured to detect diffuse reflective light from the tissue; and a controller (613) including a tissue inflammation detection unit (614) configured to analyze the detected diffuse reflective light in its spectral components. The tissue inflammation detection unit is configured to: determine a tissue contribution from a first wavelength region of a diffuse reflective spectroscopy signal where the diffuse reflective spectroscopy signal is dominated by tissue; extrapolate the tissue contribution to a second wavelength region where the diffuse reflective spectroscopy signal includes at least one detectable hemoglobin absorption feature; subtract the extrapolated tissue contribution from the diffuse reflectance signal; and determine the degree of tissue inflammation. ## Claims ### Claim 1 A system for detecting tissue inflammation, comprising: a light emitter configured to emit light towards tissue; at least one light detector configured to detect diffuse reflective light reflected from said tissue; and a controller comprising a tissue inflammation detection unit configured to analyze the detected diffuse reflective light in its spectral components, said tissue inflammation detection unit configured to: determine a tissue contribution from a first wavelength region of a diffuse reflective spectroscopy signal where the diffuse reflective spectroscopy signal is dominated by tissue; extrapolate the tissue contribution according to a predetermined wavelength-dependent function to a second wavelength region where the diffuse reflective spectroscopy signal comprises at least one detectable hemoglobin absorption feature; subtract the extrapolated tissue contribution from the diffuse reflective spectroscopy signal; and determine the degree of tissue inflammation. ### Claim 2 (depends on 1) The tissue inflammation detection system of claim 1, wherein said system is configured to detect gingivitis. ### Claim 3 (depends on 1) The tissue inflammation detection system of claim 1, wherein said tissue inflammation detection unit is configured to determine the tissue contribution at first and second wavelengths which are greater than 665 nm within the first wavelength region. ### Claim 4 (depends on 3) The tissue inflammation detection system of claim 3, wherein said tissue inflammation detection unit is configured to extrapolate the tissue contributions to third and fourth wavelengths within the second wavelength region, where the wavelengths in said second wavelength region are shorter than the wavelengths in said first wavelength region. ### Claim 5 (depends on 4) The tissue inflammation detection system of claim 4, wherein said second wavelength region is 400 nm to 600 nm. ### Claim 6 (depends on 1) The tissue inflammation detection system of claim 1, further comprising a diffuse reflective spectroscopy probe having a source-detector separation that is greater than 300 pm. ### Claim 7 (depends on 1) The tissue inflammation detection system of claim 1, wherein the at least one light detector is at least four wavelength-sensitive detectors, configured to detect diffuse reflective light at said at least first, second, and third wavelengths reflected from said tissue. ### Claim 8 A method for detecting tissue inflammation, comprising: determining, by a controller, a tissue contribution at least a first and second wavelengths within a first wavelength region of a diffuse reflective spectroscopy signal where the diffuse reflective spectroscopy signal is dominated by tissue; extrapolating, by the controller, the tissue contributions to at least a third and fourth wavelengths within a second wavelength region where the diffuse reflective spectroscopy signal comprises at least one detectable hemoglobin absorption feature; subtracting, by the controller, the extrapolated tissue contributions from the diffuse reflective spectroscopy signal at the at least third and fourth wavelengths to provide blood contributions at the at least third and fourth wavelengths; and determining, by the controller, the degree of tissue inflammation based on first and second blood contributions. ### Claim 9 (depends on 8) The method of claim 8, wherein the tissue inflammation is gingivitis. ### Claim 10 (depends on 8) The method of claim 8, further comprising the step of detecting, by four wavelength-sensitive detectors, diffuse reflective light at said at least first, second, third, and fourth wavelengths prior to the step of determining the tissue contributions. ### Claim 11 (depends on 8) The method of claim 8, wherein said first and second wavelengths are longer than said third and fourth wavelengths. ### Claim 12 (depends on 8) The method of claim 8, wherein the step of extrapolating the tissue contributions involves a predetermined wavelength-dependent function. ### Claim 13 (depends on 8) The method of claim 8, further comprising the step of emitting light towards tissue using at least four light sources emitting light at said first, second, third, and fourth wavelengths. ### Claim 14 (depends on 13) The method of claim 13, further comprising the step of detecting, by at least one detector, diffuse reflective light emitted by said at least four light sources.