# US 2025/0151973 A1 · A system and method for tissue analysis using remote ppg > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0151973 A1 - Document ID: US20250151973A1 - Status: Published application - Kind: A1 - Application number: 18/838,646 - Filed: 2023-02-15 - Published: 2025-05-15 - Earliest claimed: 2022-02-18 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Marco LAI; Bernardus Hendrikus Wilhelmus HENDRIKS - Web page: https://patentgrep.com/patent/US20250151973A1 ## CPC - A61B 1/00009: {of image signals during a use of endoscope} - A61B 5/0075: {by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy (A61B5/0071 takes precedence)} - A61B 1/042: {characterised by a proximal camera, e.g. a CCD camera} - A61B 1/05: characterised by the image sensor, e.g. camera, being in the distal end portion - A61B 5/0261: {using optical means, e.g. infrared light} - A61B 5/0295: using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography - A61B 5/6846: {specially adapted to be brought in contact with an internal body part, i.e. invasive} - G06T 7/0012: {Biomedical image inspection} - G06T 7/30: Determination of transform parameters for the alignment of images, i.e. image registration - G06T 7/60: Analysis of geometric attributes - G06T 2207/10036: Multispectral image; Hyperspectral image - G06T 2207/20: Special algorithmic details - G06T 2207/30101: Blood vessel; Artery; Vein; Vascular - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A PPG imaging system and method processes images to derive remote PPG signals. Images of a region of interest are received, and landmarks are identified in each of a set of the images. For pairs of images of the set, the landmarks between first and second images of the pair are paired, and the second image is deformed to match the landmarks in that second image with the landmarks in the first image thereby providing motion compensation. A remote PPG signal is obtained from a set of the motion-compensated images. ## Claims ### Claim 1 A processor for a PPG imaging system, for processing images to derive remote PPG signals, the processor being adapted to: receive images of a region of interest; identify landmarks in each of a set of the images; for pairs of images of the set: pair the landmarks between a first image of the pair and a second image of pair; and deform said second image of the pair to match the landmarks in that second image of the pair with the landmarks in the first image of the pair thereby providing motion compensation between said pair of images; and derive the set of remote PPG signals from a set of the motion-compensated images. ### Claim 2 (depends on 1) The processor of claim 1, wherein the processor is adapted to derive a set of remote PPG signals comprising a PPG perfusion map based on PPG amplitude levels obtained from the motion-compensated images at a set of image locations. ### Claim 3 (depends on 2) The processor of claim 2, wherein the processor is adapted to derive a set of remote PPG signals comprising a PPG delay map based on PPG relative delays between image locations. ### Claim 4 (depends on 1) The processor of claim 1, wherein the images comprise 2D camera images. ### Claim 5 (depends on 1) The processor of claim 1, wherein the images comprise hyperspectral camera images. ### Claim 6 (depends on 1) The processor of claim 1, wherein the landmarks comprise a pattern of a microvasculature visible at the surface of the region of interest. ### Claim 7 (depends on 6) The processor of claim 6, wherein the pattern of microvasculature is encoded as branch points and/or vessel lengths. ### Claim 8 (depends on 1) The processor of claim 1, wherein the landmarks comprise applied surgical features such as staples or sutures. ### Claim 9 (depends on 1) The processor of claim 1, adapted to deform the second image of the pair by using an algorithm that combines image registration and deformation, such as a Free Form Deformation algorithm or a Thin Plate Spines algorithm. ### Claim 10 (depends on 1) A system comprising a processor of claim 1, and an image camera for capturing the images of the region of interest. ### Claim 11 (depends on 10) The system of claim 10, further comprising an endoscope, wherein the image camera is mounted at a distal end of the endoscope or at the proximal end of the endoscope. ### Claim 12 A method for processing images to derive remote PPG signals, comprising: receiving images of a region of interest; identifying landmarks in each of a set of the images; for pairs of the images of the set: pairing the landmarks between a first image of the pair and a second image of the pair; and deforming said second image of the pair to match the landmarks in that second image of the pair with the landmarks in the first image of the pair thereby providing motion compensation between said first and second images; and deriving a remote PPG signal from a set of the motion-compensated images. ### Claim 13 (depends on 12) The method of claim 12, comprising: deriving a set of remote PPG signals as a PPG perfusion map based on PPG amplitude levels obtained from the images at a set of image locations; and/or deriving a set of remote PPG signals as a PPG delay map based on PPG relative delays between image locations. ### Claim 14 (depends on 12) A computer program comprising computer program code means which is adapted, when said program is run on a computer, to implement the method of claim 12. ### Claim 15 (depends on 14) A processor which is programed with the computer program of claim 14.