SYSTEM FOR CAMERA-BASED VITAL SIGN MEASUREMENT

• US 20150105670A1
• Filed: 06/11/2013
• Published: 04/16/2015
• Est. Priority Date: 06/12/2012
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Muehlsteff, Jens, Shan, Caifeng, Bresch, Erik, Tigges, Timo, Dubielczyk, Alexander
• Granted Patent: US 9,943,371 B2
• Time in Patent Office: Days
• US Class Current: 600/479
• CPC Class Codes: A61B 2090/3937 Visible markers
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1127 using markers
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/117 Identification of persons methods or arrangements for recognising patterns, e.g. fingerprints, G06F18/00, G06V40/00; identification of persons by analysing their voice or speech G10L17/00
• CPC Class Codes: A61B 5/441 Skin evaluation, e.g. for skin disorder diagnosis
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

The present invention relates to the measurement of vital signs such as a respiratory rate or a heart rate. In particular, a system (1) for determining a vital sign of a subject (100), comprising an imaging unit (2) for obtaining video data of the subject, a marker (10, 20, 60, 61) directly or indirectly attached to a body of the subject, wherein the marker comprises a graphical pattern (11, 21), an image processing unit (3) for detecting said marker in said video data, and an analysis unit (4) adapted to extract a vital sign parameter related to the vital sign of the subject from said video data and to determine the vital sign from said vital sign parameter. Further aspects of the invention relate to a device and a method for determining a vital sign of a subject and a computer program for carrying out said method.

Claims

1. A system for determining a vital sign of a subject comprising

an imaging unit for obtaining video data of the subject,

a marker attachable to a body of the subject, wherein the marker comprises a machine readable graphical pattern, and wherein the graphical pattern comprises encoded data,

an image processing unit for detecting said marker in said video data and for determining said encoded data from said graphical pattern, and

an analysis unit adapted to extract in dependence of the encoded data a vital sign parameter related to the vital sign of the subject from said video data and to determine the vital sign from said vital sign parameter.

2. The system according to claim 1,

wherein said vital sign parameter is a respiratory movement of the subject and

wherein said vital sign is a respiratory rate of the subject.

3. The system according to claim 1,

wherein said vital sign parameter is a temporal variation of a skin color of the subject and wherein said vital sign is a heart rate of the subject and/or a concentration of a substance in blood and/or tissue.

4. The system according to claim 1, the marker further comprising

an orientation indicator for indicating the orientation of the marker.

5. The system according to claim 1,

wherein the marker is arranged on a fabric that is adapted to contact the subject or a medical item that is adapted to contact the subject.

6. The system according to claim 1,

wherein the marker is adapted to at least partially cover a region of interest of the body of the subject which suits for deriving the vital sign.

7. The system according to claim 1,

wherein the marker is adapted to be positioned on or adjacent to the chest of the subject.

8. The system according to claim 1,

wherein the analysis unit is calibrated using a location and/or orientation of the marker.

9. The system according to claim 1, wherein the image processing unit is adapted to determine a measurement quality metric.

11. The system according to claim 1, further comprising

a second imaging unit for obtaining second video data of the subject,

a second image processing unit for detecting said marker in said second video data.

12. The system according to claim 11,

wherein said imaging unit comprises a filter for selectively transmitting light at a first wavelength, and

wherein said second imaging unit comprises a second filter for selectively transmitting light at a second wavelength.

10. (canceled)

13. A device for determining a vital sign of a subject comprising

an imaging unit for obtaining video data of the subject,

an image processing unit for detecting a marker in said video data, wherein said marker is attachable to a body of the subject, and, wherein the marker comprises a machine readable graphical pattern, and wherein the graphical pattern comprises encoded data and for determining said encoded data from said graphical pattern, and

an analysis unit adapted to extract in dependence of the encoded data a vital sign parameter related to the vital sign of the subject from said video data and to determine the vital sign from said vital sign parameter.

14. A method for determining a vital sign of a subject, comprising the steps of

step 1 attaching a marker to a body of the subject, wherein the marker comprises a machine readable graphical pattern and wherein the graphical pattern comprises encoded data.

step 2 obtaining video data of the subject,

step 3 detecting said marker in said video data and determining said encoded data from said graphical pattern,

step 4 extracting in dependence of the encoded data a vital sign parameter related to the vital sign of the subject from said video data, and

step 5 determining the vital sign from said vital sign parameter.

15. A computer program comprising program code means for causing a computer to carry out the steps 2-5 of the method as claimed in claim 14 when said computer program is carried out on the computer.