Differentiating among a plurality of subjects in a field-of-view based on vital signs

• US 9,218,668 B2
• Filed: 02/24/2014
• Issued: 12/22/2015
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Rocque, Mukul Julius
• Primary Examiner(s): ANSARI, TAHMINA N
• Application Number:
  US14/187,588
• Publication Number:
  US 20140241588A1
• Time in Patent Office: 666 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/20021 Dividing image into blocks, subimages or windows
• CPC Class Codes: G06T 2207/30076 Plethysmography
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/215 Motion-based segmentation
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G06V 40/15 Biometric patterns based on physiological signals, e.g. heartbeat, blood flow
• CPC Class Codes: G06V 40/20 Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16

Abstract

An apparatus for detecting different subjects on the basis of vital signs includes an image detection unit for detecting radiation from a field of view and for providing image data from the field of view. A detection unit defines image sections in the image data and detects movement patterns in each of the different image sections. An identification unit identifies vital signs in the different image section on the basis of the movement pattern. An analysis unit analyzes the image data and detects the different subjects in the field of view on the basis of a spatial separation of the image sections or of groups of image sections in which the vital signs are identified.

Claims

1. An apparatus for detecting different subjects on the basis of vital signs, comprising:

a camera configured to detect radiation from a field of view and provide image data from the field of view,

a detection unit that defines image sections in the image data and that detects movement patterns in the different image sections,

an identification unit that identifies vital signs in the different image section on the basis of the movement patterns, and

an analysis unit that

combines connected image sections in which vital signs are detected in a first group of image sections on the basis of a spectral parameter and a predefined threshold value of the movement patterns of the image sections,

combines connected image sections in which vital signs are detected which are separated from the first group of image sections into a second group of image sections on the basis of the spectral parameter and the predefined threshold of movement patterns of the image sections,

detects the different subjects in the field of view on the basis of the groups of image sections, the first group of image sections corresponding to a first subject and the second group corresponding to a second subject.

2. The apparatus as claimed in claim 1, wherein the movement patterns are determined on the basis of frame detection.

3. The apparatus as claimed in claim 1, wherein the identification unit is adapted to derive an alternating signal from the respective movement pattern for each of the image sections.

4. The apparatus as claimed in claim 3, wherein the identification unit comprises a frequency analysis device that analyses a frequency spectrum of the alternating signals in order to identify the vital signs.

5. The apparatus as claimed in claim 4, wherein the frequency analysis device is adapted to determine the spectral parameter on the basis of each of the alternating signals to identify the vital signs.

6. The apparatus as claimed in claim 5, wherein the frequency analysis device is adapted to determine a spectral energy of a predefined spectral range as the spectral parameter.

7. The apparatus as claimed in claim 1, wherein the first group of image sections is defined by selecting an initial image section on the basis of the spectral parameter and wherein image sections adjacent to the initial image section are selected as image sections of the first group on the basis the respective spectral parameter and the predefined threshold level.

8. The apparatus as claimed in claim 7, wherein the second group of image sections is defined by selecting an initial image section separated from the first group of image sections on the basis of the spectral parameter and wherein image sections adjacent to the initial image section are selected as connected image sections of the second group on the basis the respective spectral parameter and the predefined threshold level.

9. The apparatus as claimed in claim 7, wherein the image sections having the highest spectral parameter value are selected as the initial image sections.

10. A method for detecting different subjects on the basis of vital signs, comprising the steps of:

detecting radiation from a field of view and providing image data from the field of view;

defining image sections in the image data by dividing the field of view into sections;

detecting movement patterns in the image sections;

identifying a first group of connected image sections in which the detected movement pattern is indicative of a vital sign;

identify a second group of connected image sections in which the detected movement pattern is indicative of a vital sign, the second group of connected image sections being separated from the first group of connected image sections; and

identifying first and second subjects in the field of view on the basis of the first and second groups of connected image sections.

11. A computer readable non-transitory medium having instructions stored thereon which, when carried out on a computer, cause the computer to perform the method as claimed in claim 10.

12. The method as claimed in claim 10, further including:

outputting a vital sign of the first subject based on the movement pattern from the first group of connected image sections; and

outputting a vital sign of the second subject based on the movement pattern from the second group of connected image sections.

13. An apparatus for detecting different subjects on the basis of vital signs, comprising:

a camera configured to detect radiation from a field of view and provide image data from the field of view;

one or more processors configured to;

receive the image data from the camera,

subdivide the field of view into image sections,

detect movement patterns in the image sections,

based on the detected movement patterns, identifying vital signs in a plurality of the image sections,

combining image sections in which vital signs have been identified into a plurality of groups of image sections, each group including connected image sections in which the vital signs were identified, the groups being separated from each other, and

associating each group with a different one of the subjects to detect the different subjects.

14. The apparatus as claimed in claim 13, wherein the one or more processors is further configured to:

deriving an alternating signal from the motion pattern in each of the image sections;

analyzing a frequency spectrum of the alternating signals to identify the vital signs.

15. The apparatus as claimed in claim 14, wherein the one or more processors is further configured to identify a first of the subjects by:

identifying a first group of connected image sections based on the spectral parameter and a predefined threshold value, the first group corresponding to a first of the subjects.

16. The apparatus as claimed in claim 15, wherein the one or more processors is further configured to identify a second of the subjects by:

identifying a second group of connected image sections based on the spectral parameter and a predefined threshold value, the second group corresponding to a second of the subjects.

17. The apparatus as claimed in claim 15, wherein the one or more processors are configured to define the first group of connected image sections by:

selecting an initial image section based on the spectral parameter; and

selecting image sections adjacent to the initial image section based on the spectral parameter and the predefined threshold level.

18. The apparatus as claimed in claim 17, wherein the one or more processors are configured to select the initial image section by:

finding an initial image section with the highest value of the spectral parameter.

19. The apparatus as claimed in claim 17, wherein the one or more processors are configured to define the second group of connected image sections by:

selecting a second initial image section based on the spectral parameter; and

selecting image sections adjacent to the second initial image section based on the spectral parameter and the predefined threshold level.