METHODS AND SYSTEMS FOR MEASURING DYNAMIC CHANGES IN THE PHYSIOLOGICAL PARAMETERS OF A SUBJECT

• US 20130296660A1
• Filed: 05/02/2012
• Published: 11/07/2013
• Est. Priority Date: 05/02/2012
• Status: Active Grant

• Current Assignee: Banna Biomedical Research Institute
• Original Assignee: Georgia Health Sciences University (University System of Georgia)
• Inventors: Tsien, Joseph Z., Li, Meng, Zhao, Fang, Qian, Yi
• Granted Patent: US 10,143,377 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/004 adapted for image acquisition of a particular organ or body part A61B5/0082 takes precedence; arrangements for optical scanning A61B5/0062
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0255 Recording instruments specially adapted therefor
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 2207/30076 Plethysmography
• CPC Class Codes: G06T 7/0016 involving temporal comparison

Abstract

Methods for remotely measuring or monitoring one or more physiological parameters in a subject, such as blood volume pulse, heart rate, respiratory wave, or respiration rate, are provided. The methods include capturing a series of images of the subject, and processing the images to obtain physiological parameters of interest. These methods can be used to analyze single channel signals, including signals obtained from active night vision cameras. As a result, these methods can be used to measure or monitor one or more physiological parameters in both daylight and low-light conditions. Also provided are methods of removing false positives. Systems for remotely measuring or monitoring one or more physiological parameters in a subject, as well as methods of using thereof, are also provided.

Claims

1. A method for measuring one or more physiological parameters in a subject comprising

capturing a sequence of single channel images of a subject;

establishing a region of interest for each of the one or more physiological parameters to be measured;

separating each region of interest into two or more subsets;

spatially averaging pixels in a first subset within each region of interest to yield a single observed time series over time; and

processing the single observed time series to obtain values for the one or more physiological parameters.

2. The method of claim 1, wherein the one or more physiological parameters are selected from the group consisting of blood volume pulse, heart rate, respiratory wave, respiration rate, and combinations thereof.

3. The method of claim 1, wherein more than one physiological parameter is measured simultaneously.

4. The method of claim 1, wherein the images are captured using an active night vision camera.

5. The method of claim 1, wherein the physiological parameter is heart rate, blood volume pulse, or combinations thereof, and the region of interest is an area of the skin of the subject.

6. The method of claim 1, wherein the physiological parameter is respiration rate, respiratory wave, or combinations thereof, and the region of interest is an area of the chest or abdomen of the subject.

7. The method of claim 1, further comprising detrending the single observed time series over time.

8. The method of claim 1, further comprising normalizing the single observed time series over time.

9. The method of claim 1, wherein processing the single observed time series comprises constructing an embedded matrix from a series of delay vectors.

10. The method of claim 9, wherein processing the single observed time series further comprises deconstructing the embedded matrix into its underlying independent components.

11. The method of claim 10, wherein the embedded matrix is deconstructed using independent component analysis.

12. The method of claim 10, wherein one of the underlying independent components is processed to obtain a physiological parameter using moving average filtering, multilayer autocorrelation, fast Fourier transformation, and combinations thereof.

13. The method of claim 1, further comprising

processing a second subset within each region of interest, and

comparing the physiological parameter obtained by processing the first subset within each region of interest and processing the second subset within each region of interest to remove false positives.

14. The method of claim 1, wherein the images are captured using an active night vision camera.

15. An apparatus for remotely measuring or monitoring one or more physiological parameters in a subject comprising

an image acquisition device which produces a single channel signal;

signal processing circuitry or a processor configured to process the single channel signals to obtain one or more physiological parameters.

16. The apparatus of claim 15, wherein the image acquisition device is an active night vision camera.

17. The apparatus of claim 15, wherein the image acquisition device is a photodetector.