System and method for using a video monitoring system to prevent and manage decubitus ulcers in patients

• US 20120026308A1
• Filed: 07/29/2010
• Published: 02/02/2012
• Est. Priority Date: 07/29/2010
• Status: Active Grant

• Current Assignee: Careview Communications Incorporated
• Original Assignee: Careview Communications Incorporated
• Inventors: Johnson, Steve Gail, Ecker, Stephen, Johnson, Kyle Brook, Clark, Matthew Cameron, Kuether, Richard Craig
• Granted Patent: US 8,675,059 B2
• Time in Patent Office: Days
• US Class Current: 348/77
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 2207/30201 Face
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 20/40 in video content extracting overlay text G06V20/62; video retrieval G06F16/70; processing of video elementary streams in video servers H04N21/234; processing of video elementary streams in video clients H04N21/44
• CPC Class Codes: G06V 20/44 Event detection
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 40/103 Static body considered as a whole, e.g. static pedestrian or occupant recognition
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A video monitoring system captures image frames of a patient in various positions. The captured image frames are analyzed by the system for changes in a patient'"'"'s position or movement, frames in which the system detects one or both of patient movement and repositioning are retained. The system analyzes an area of interest within each image frame that corresponds to an area in the camera'"'"'s view field with the patient. Sequential image frames are compared for motion, only frames without motion, where the patient is still, are analyzed. Analysis techniques include selecting a plurality of vertical positions in the area of interest, each vertical position corresponding to a part of the patient body indicative of the patient'"'"'s position, horizontally scanning values along the horizontal pixel row at each vertical position in the area of interest, finding an average value for each vertical position and identifying a patient interval of the horizontal pixel row having pixel values different from the average and a representative horizontal position of the patient interval for each vertical interval. Then, comparing those median horizontal positions from a current image frame to the representative horizontal positions from a previous image frame to determine a change in the patient'"'"'s position.

Claims

1. A method for using a video monitoring system to prevent and manage decubitus ulcers in patients, comprising:

receiving a first image frame containing the patient from a video camera;

describing a first patient position with regard to a pixel attribute at each of a plurality of vertical positions within the first image frame;

accessing a second patient position with regard to the pixel attribute at each of the plurality of vertical positions within a second image frame;

detecting a patient repositioning event between the second patient position and the first patient position;

associating information related to the patient repositioning event with the first image frame;

retaining the first image frame and the associated information; and

issuing an alert for the patient repositioning event.

2. The method recited in claim 1, further comprises:

identifying a plurality of vertical positions within an image frame.

3. The method recited in claim 2, wherein each of the plurality of vertical positions corresponding to a body part of the patient indicative of a patient position.

4. The method recited in claim 1, further compromises:

receiving a description of an area of interest within an image frame at the video monitoring system, said area of interest within the image frame corresponding to a portion of a camera view field containing a patient.

5. The method recited in claim 3, further compromises:

receiving a description of an area of interest within an image frame at the video monitoring system, said area of interest within the image frame corresponding to a portion of a camera view field containing a patient.

6. The method recited in claim 3, wherein describing the first patient position with regard to a pixel attribute at each of the plurality of vertical positions within the first image frame further comprises:

describing the first patient position within the first image frame as a first plurality of horizontal positions within the first image frame, for each of the plurality of vertical positions finding a single horizontal position representative of a position corresponding to the respective body part, comprising;

horizontally scanning pixel values for the pixel attribute along the horizontal pixel row in the first image frame;

finding a representative pixel value for the horizontal pixel row;

finding an interval of pixels for the horizontal pixel row having pixel values different from the representative pixel value;

identifying the interval of pixels as the patient; and

finding a single horizontal position within the interval of pixels representative of the patient position at the vertical position.

7. The method recited in claim 6, wherein detecting a patient repositioning event between the second patient position and the first patient position further comprises:

comparing each of the first plurality of horizontal positions describing the first patient position from the first image frame with a respective each of a second plurality of horizontal positions describing the second patient position from the second image frame.

8. The method recited in claim 5, wherein describing the first patient position with regard to the pixel attribute at each of the plurality of vertical positions within the first image frame further comprises:

describing the first patient position within the area of interest of the first image frame as a first plurality of horizontal positions within the area of interest of the first image frame, for each of the plurality of vertical positions within the area of interest finding a single horizontal position representative of a position corresponding to the respective body part, comprising;

horizontally scanning pixel values for the pixel attribute along the horizontal pixel row within the area of interest of the first image frame;

finding a representative pixel value for the horizontal pixel row;

finding an interval of pixels for the horizontal pixel row having pixel values different from the representative pixel value;

identifying the interval of pixels as the patient; and

finding a single horizontal position within the interval of pixels representative of the patient position at the vertical position.

9. The method recited in claim 3, wherein detecting a patient repositioning event between the second patient position and the first patient position further comprises:

deriving a first plurality of angular relationships describing the first patient position by finding an angular relationship between pairs of horizontal positions at the plurality of vertical positions; and

comparing each of the first plurality of angular relationships describing the first patient position from the first image frame with each of a second plurality of angular relationships describing the second patient position from the second image frame.

10. The method recited in claim 3, wherein detecting a patient repositioning event between the second patient position and the first patient position further comprises:

deriving a first plurality of angular relationships describing the first patient position by finding an angular relationship between pairs of horizontal positions at the plurality of vertical positions;

comparing each of the first plurality of angular relationships describing the first patient position with a library of unique body positions, each of the unique body position described by a unique set of angular relationships between pairs of horizontal positions at the plurality of vertical positions;

identifying a first unique patient body position from the library of unique body positions; and

comparing the first unique patient body position describing the first patient position from the first image frame with a second unique patient body position describing a second patient position from the second image frame.

11. The method recited in claim 10, wherein the pairs of horizontal positions are between adjacent vertical positions.

12. The method recited in claim 5, wherein detecting a patient repositioning event between the second patient position and the first patient position further comprises:

deriving a first plurality of angular relationships describing the first patient position by finding an angular relationship between pairs of horizontal positions within the area of interest at the plurality of vertical positions;

comparing each of the first plurality of angular relationships describing the first patient position with a library of unique body positions, each of the unique body positions described by a unique set of angular relationships between pairs of horizontal positions at the plurality of vertical positions;

identifying a first unique patient body position from the library of unique body positions; and

comparing the first unique patient body position describing the first patient position from the first image frame with a second unique patient body position describing the second patient position from the second image frame.

13. The method recited in claim 12, wherein the pairs of horizontal positions within the area of interest are between adjacent vertical positions.

14. The method recited in claim 1, wherein issuing an alert for the patient repositioning event further comprises:

transmitting the alert for the patient repositioning event to a remote location from the video camera; and

generating one of an audible alarm, a visual alarm, an audible message and a visual message at the remote location from the video camera.

15. The method recited in claim 14, further comprises:

escalating the alert for the patient repositioning event to a second remote location from the video camera by generating one of an audible alarm, a visual alarm, an audible message, a visual message, an email message and a text message invoked at the second remote location.

16. The method recited in claim 1, wherein issuing an alert for the patient repositioning event further comprises:

generating one of an audible alarm, a visual alarm, an audible message and a visual message locally to the video camera.

17. The method recited in claim 6, wherein detecting a patient repositioning event further comprises:

comparing each of the first plurality of horizontal positions describing the first patient position from the first image frame with each of a third plurality of horizontal positions describing a third patient position from a third image frame, wherein the third image frame immediately proceeds the first image frame;

detecting a change between the first plurality of horizontal positions and the third plurality of horizontal positions at the respective vertical positions;

receiving a fourth image frame based on detecting the change between the first plurality of horizontal positions and the third plurality of horizontal positions at the respective vertical positions;

describing a fourth patient position within the fourth image frame as a fourth plurality of horizontal positions within the fourth image frame, for each of the plurality of vertical positions finding a single horizontal position representative of a position corresponding to the respective body part, comprising;

horizontally scanning pixel values for the pixel attribute along the horizontal pixel row in the fourth image frame;

finding a representative pixel value for the horizontal pixel row;

finding an interval of pixels for the horizontal pixel row having pixel values different from the representative pixel value;

identifying the interval of pixels as the patient; and

finding a single horizontal position within the interval of pixels representative of the patient position at the vertical position; and

detecting a second patient repositioning event between the second patient position and the fourth patient position;

associating information related to the second patient repositioning event with the fourth image frame;

retaining the fourth image frame image frame and the associated information; and

issuing an alert for the second patient repositioning event.

18. The method recited in claim 1, further comprising:

associating information related to a plurality of patient repositioning events with a respective plurality of image frames;

retaining the plurality of image frames; and

creating a video history of the patient'"'"'s positions from the plurality of image frames.

19. The method recited in claim 10, further comprising:

receiving a patient schedule of compliant patient body positions, said patient schedule of compliant patient body positions comprising a plurality of compliant patient body positions and a corresponding plurality time intervals; and

comparing the first unique patient body position describing the first patient position to the patient schedule of compliant patient body positions.

20. The method recited in claim 1, wherein the pixel attribute is one of chrominance and luminance.

21. The method recited in claim 1, wherein the pixel attribute is luminance.

22. The method recited in claim 1, wherein the vertical positions are horizontal pixel rows and describing a first patient position with regard to a pixel attribute at each of the plurality of vertical positions within the first image frame further comprises:

scanning pixel values for the pixel attribute in the first image frame;

recognizing the regularly repeating pattern from the pixel values for the pixel attribute;

determining an orientation of the regularly repeating pattern on the bed linens; and

assessing the first patient position from the orientation of the regularly repeating pattern on the bed linens.

23. The method recited in claim 4, wherein the vertical positions are horizontal pixel rows and describing the first patient position with regard to the pixel attribute at each of the plurality of vertical positions within the first image frame further comprises:

subdividing the area of interest into a plurality of equal-sized pixel zones, each of the plurality of equal-sized pixel zones containing an equal number of pixels;

scanning pixel values for the pixel attribute in the area of interest of the first image frame;

assigning at least one patient pixel value;

determining a zone weight for each plurality of equal-sized pixel zones based on pixels contained in a respective zone having the at least one patient pixel value; and

summing the zone weights of the plurality of equal-sized pixel zones within the area of interest of the first image frame.

24. The method recited in claim 23, wherein assigning at least one patient pixel value further comprising:

deriving boundaries between areas of like pixel values;

grouping areas of like pixel values;

selecting one area as the patient, pixels in said one having the at least one patient pixel value.

25. The method recited in claim 24, wherein deriving boundaries between areas of like pixel values further comprising:

identifying elevated contrasts between adjacent pixels based on dissimilar pixel values between the adjacent pixels; and

forming contrast contours bounding areas of like pixel values.

26. The method recited in claim 23, wherein the second patient position is a second sum of zone weights of the plurality of equal-sized pixel zones within the area of interest of the first image frame and detecting a patient repositioning event between the second patient position and the first patient position further comprising:

finding a cumulative zone weight difference between the second sum of zone weights and the first sum of zone weights; and

comparing the cumulative zone weight difference to a threshold patient repositioning zone weight.

27. The method recited in claim 23, wherein the pixel attribute is one of chrominance and luminance.

28. The method recited in claim 4, wherein the vertical positions are horizontal pixel rows and describing the first patient position with regard to the pixel attribute at each of the plurality of vertical positions within the first image frame further comprises:

horizontally scanning pixel values for the pixel attribute in the area of interest of the first image frame;

deriving boundaries between areas of like pixel values;

grouping areas of like pixel values;

selecting a patient area having the at least one patient pixel value;

identifying a head-end of the patient area;

commencing at the head-end, scanning laterally across the patient area;

identifying at least one of a patient head, a patient neck and a patient shoulder within the patient area;

identifying features of the at least one of a patient head, a patient neck, and a patient shoulder within the patient area; and

assessing the first patient position from the features of the at least one of the patient head, the patient neck, and the patient shoulder.

29. The method recited in claim 28, wherein a patient head is identified and identifying features of the at least one of a patient head, a patient neck, and a patient shoulder within the patient area further comprises:

scanning pixel values for the pixel attribute at the patient head within the area interest of the first image frame;

identifying elevated contrasts between adjacent pixels based on dissimilar pixel values between the adjacent pixels;

forming contrast contours bounding areas of like pixel values; and

identifying one of a patient eye, a pair of patient eyes, a patient ear, a pair of patient ears and an orientation of a pair of patient shoulders.

30. The method recited in claim 28, wherein the pixel attribute is one of chrominance and luminance.

31. The method recited in claim 1, further comprising:

transmitting the first image frame to a remote location from the video camera; and

displaying the first image at the remote location.

32. The method recited in claim 1, wherein the patient is recumbent in one of a patient bed, gurney and medical apparatus in the first image frame.

33. The method recited in claim 1, wherein the patient is seated at a chair, wheelchair and medical apparatus in the first image frame.

34. A method for using a video monitoring system to prevent and manage decubitus ulcers in patients, comprising:

receiving a decubitus ulcer patient repositioning schedule at the video monitoring system, said patient repositioning schedule comprises a plurality of patient positions, each of the plurality of patient positions corresponding to patient position time interval;

receiving a first image frame from a surveillance camera, said image frame containing the patient in a current position;

monitoring an elapsed time in the current patient position;

identifying the current patient position in the decubitus ulcer patient repositioning schedule;

comparing the elapsed time and the patient position time interval from the decubitus ulcer patient repositioning schedule corresponding to the current patient position;

detecting a patient repositioning event based on the comparison;

associating information related to the patient repositioning event with the first image frame;

retaining the first image frame and the associated information; and

issuing an alert for the patient repositioning event.

35. The method recited in claim 34, further compromises:

receiving a description of an area of interest within an image frame at the video monitoring system, said area of interest within the image frame corresponding to a portion of a camera view field containing a patient.

36. The method recited in claim 34, wherein issuing an alert for the patient repositioning event further comprises:

transmitting the alert for the patient repositioning event to a remote location from the video camera; and

generating one of an audible alarm, a visual alarm, an audible message and a visual message at the remote location from the video camera.

37. The method recited in claim 36, further comprises:

escalating the alert for the patient repositioning event to a second remote location from the video camera by generating one of an audible alarm, a visual alarm, an audible message, a visual message, an email message and a text message invoked at the second remote location.

38. The method recited in claim 34, wherein issuing an alert for the patient repositioning event further comprises:

generating one of an audible alarm, a visual alarm, an audible message and a visual message locally to the video camera.

39. The method recited in claim 34, further comprising:

transmitting the first image frame to a remote location from the video camera; and

displaying the first image at the remote location.