MEASURING MULTIPLE PHYSIOLOGICAL PARAMETERS THROUGH BLIND SIGNAL PROCESSING OF VIDEO PARAMETERS

• US 20140275833A1
• Filed: 03/10/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Original Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Inventors: Vanderpohl, Irvin J. III
• Granted Patent: US 10,238,292 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/16 Devices for psychotechnics using teaching or educational appliances G09B1/00 - G09B7/00; Testing reaction times ; Devices for evaluating the psychological state
• CPC Class Codes: A61B 5/6891 Furniture
• CPC Class Codes: A61G 7/002 having adjustable mattress frame
• CPC Class Codes: A61G 7/05 Parts, details or accessories of beds devices for prevention against falling out A47C21/08, A47D7/00 ; mattresses A47C27/00

Abstract

A patient support system includes a patient support apparatus, a camera, and a controller. The controller is configured to receive image data from the camera and to determine at least one of pulmonary and circulatory characteristics of a patient supported on the patient support apparatus.

Claims

1. A patient support system comprising

a patient support apparatus,

a camera, and

a controller coupled to the patient support apparatus and to the camera, the controller configured to receive image data from the camera and to determine at least one of pulmonary and circulatory characteristics of a patient supported on the patient support apparatus.

2. The patient support system of claim 1, wherein the controller is configured to determine relative blood pressure value of a patient supported on the patient support apparatus based on image data from the camera.

3. The patient support system of claim 2, wherein the controller is configured to resolve color signals corresponding to a patient face and to a patient extremity based on image data from the camera, to determine blood volume pulse information corresponding to the patient face and to the patient extremity based on the color signal, and to determine a relative blood pressure value based on the blood volume pulse information corresponding to the patient face and to the patient extremity.

4. The patient support system of claim 3, wherein resolving color signals corresponding to the patient face and to the patient extremity includes determining which portion of the image data contains a patient face and which portion of the image data contains a patient extremity.

5. The patient support system of claim 4, wherein determining which portion of the image data contains a patient face and which portion of the image data contains a patient extremity includes detecting skin and performing gradient analysis to detect body edges.

6. The patient support system of claim 4, wherein the controller is configured to enhance the portions of the image data that contain the patient face and the patient extremity.

7. The patient support system of claim 6, wherein the controller is configured to enhance the portions of the image data that contain the patient face and the patient extremity by blob processing the portions of the image data to reshape the image using convex hulls of contours and filling the area into a closed shape.

8. The patient support system of claim 7, wherein the controller is configured to process the closed shape using blind signal processing.

9. The patient support system of claim 3, wherein determining blood volume pulse information corresponding to the patient face and to the patient extremity includes transforming the color signals into three independent source signals using independent component analysis.

10. The patient support system of claim 9, wherein the independent component analysis is based on the joint approximate diagonalization of elgenmatrices algorithm.

11. The patient support system of claim 9, wherein the controller is configured to order the three independent source signals by reviewing the power spectrum of the three independent source signals.

12. The patient support system of claim 11, wherein determining blood volume pulse information corresponding to the patient face and to the patient extremity includes selecting a signal of interest with the highest peak from the three independent source signals by determining the power spectrum of the three independent signals.

13. The patient support system of claim 12, wherein controller is configured to smooth the signal of interest using a five-point moving average filter and bandpass filter.

14. The patient support surface of claim 2, wherein determining relative blood pressure based on the blood volume pulse information includes comparing time differences between peak blood volume pulse information corresponding to the patient face and peak blood volume pulse information corresponding to the patient extremity.

16. The patient support system of claim 1, wherein the camera is coupled to the patient support apparatus.

15. The patient support surface of 2, wherein the controller is configured to determine actual blood pressure based on the relative blood pressure value.

17. A method of determining a circulatory patient characteristic corresponding to a patient supported on a patient support apparatus comprising

receiving image data from a camera,

determining blood volume pulse information based on the image data, and

determining a relative blood pressure value based on the blood volume pulse information corresponding to the patient face and to the patient extremity.

18. The method of claim 17, further comprising receiving an externally entered blood pressure value and determining an actual blood pressure value based on the externally entered blood pressure value and the relative blood pressure value.

19. The method of claim 17, wherein determining relative blood pressure based on the blood volume pulse information includes comparing time differences between peak blood volume pulse information corresponding to a patient face and peak blood volume pulse information corresponding to a patient extremity.

20. The method of claim 17, wherein the image data includes data corresponding to a patient face and to a patient extremity.