System and method for extracting physiological information from remotely detected electromagnetic radiation

• US 10,575,764 B2
• Filed: 09/06/2017
• Issued: 03/03/2020
• Est. Priority Date: 08/06/2013
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: De Haan, Gerard
• Primary Examiner(s): Malamud, Deborah L
• Application Number:
  US15/696,813
• Publication Number:
  US 20170360340A1
• Time in Patent Office: 909 Days
• CPC Class Codes: A61B 2503/045 Newborns, e.g. premature baby monitoring
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence

Abstract

The present disclosure relates to a device and a method for extracting physiological information indicative of at least one health symptom from remotely detected electromagnetic radiation. The device comprises an interface for receiving a data stream comprising remotely detected image data representing an observed region comprising at least one subject of interest, wherein the image data comprises wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels representative of respective wavelength portions; an image processor for detecting channel signal strength information for at least two of the at least two color channels; and a data comparison unit for comparing detected channel signal strengths with respective reference values.

Claims

1. A photoplethysmographic monitoring system configured for extracting physiological information indicative of at least one health symptom from detected electromagnetic radiation, the photoplethysmographic monitoring system comprising:

one or more sensors configured to generate output signals conveying information related to skin radiation of a subject, the skin radiation information including wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels representative of respective wavelength portions, and the wavelength-dependent image information comprises a pulsating signal component; and

one or more processors configured by machine-readable instructions to;

receive the skin radiation information;

detect relative channel signal strength information for the at least two color channels, wherein the relative channel signal strength information corresponding to the at least two color channels is represented by color vectors, and the color vectors are moved along a path between minima and maxima corresponding to the pulsating signal component;

compare the color vectors'"'"' path with a reference vector path, wherein the reference vector path is obtained by monitoring healthy subjects;

determine blood composition-indicative information of the subject based on the comparison of the color vectors'"'"' path and the reference vector path; and

determine a level of serum bilirubin in the subject'"'"'s circulating blood based on signal strength fluctuations.

2. The photoplethysmographic monitoring system of claim 1, wherein the one or more processors are further configured to:

(i) determine a ratio of the at least two color channels,

(ii) compare the determined ratio with a reference ratio, the reference ratio obtained by monitoring the healthy subjects, and

(iii) determine blood composition-indicative information based on the comparison of the determined ratio and the reference ratio.

3. The photoplethysmographic monitoring system of claim 1, wherein the one or more sensors are disposed at a predetermined distance away from the subject, the predetermined distance being at least one decimeter.

4. The photoplethysmographic monitoring system of claim 1, wherein the at least two color channels are associated with a color model, the color model being based on a color model convention allocating respective wavelength portions to the at least two color channels, the color model is a color space based on a color space mapping convention, respective wavelength portions are assigned to respective axes of the color space, and the color space is an additive color space composed of three color channels.

5. The photoplethysmographic monitoring system of claim 1, wherein the one or more processors are further configured to determine:

(i) a level of bilirubin accumulated in the subject'"'"'s dermis based on constant or quasi-constant channel signal strengths, and

(ii) an estimate of a serum bilirubin level compared to a skin-bilirubin level.

6. The photoplethysmographic monitoring system of claim 1, wherein the one or more processors are further configured to:

determine relative channel signal strength information indicative of impending suffocation.

7. The photoplethysmographic monitoring system of claim 6, wherein the one or more processors are further configured to:

(i) determine oxygenation information based on a ratio of the detected channel signal strengths, the oxygenation information being indicative of a ratio of hemoglobin and oxyhemoglobin in the subject'"'"'s blood, and

(ii) output an alert signal responsive to the ratio exceeding a reference threshold.

8. The photoplethysmographic monitoring system of claim 1, wherein the one or more processors are further configured to:

detect at least one indicative skin portion of the subject based on the skin radiation information.

9. The photoplethysmographic monitoring system of claim 1, further comprising:

a treating radiation source configured to emit radiation in a particular wavelength range, wherein the treating radiation source is disposed such that the emitted radiation is directed to the subject, and the one or more processors are further configured to

control operation of the treating radiation source based on the determined blood composition-indicative information of the subject.

10. A method for extracting physiological information indicative of at least one health symptom from detected electromagnetic radiation with a photoplethysmographic monitoring system, the photoplethysmographic monitoring system comprising one or more sensors and one or more processors, the method comprising:

receiving, with the one or more sensors, skin radiation information of a subject, the skin radiation information including wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels representative of respective wavelength portions, and the wavelength-dependent image information comprises at least a pulsating signal component;

detecting, with the one or more processors, relative channel signal strength information for the at least two color channels, wherein the relative channel signal strength information corresponding to the at least two color channels is represented by color vectors, and wherein the color vectors are moved along a path between minima and maxima corresponding to the pulsating signal component;

comparing, with the one or more processors, the color vectors'"'"' path with a reference vector path, wherein the reference vector path is obtained by monitoring healthy subjects;

determining, with the one or more processors, blood composition-indicative information of the subject based on the comparison of the color vectors'"'"' path and the reference vector path; and

determining, with the one or more processors, a level of serum bilirubin in the subject'"'"'s circulating blood based on signal strength fluctuations.

11. The method of claim 10, further comprising:

(i) determining, with the one or more processors, a ratio of the at least two color channels;

(ii) comparing, with the one or more processors, the determined ratio with a reference ratio, the reference ratio obtained by monitoring the healthy subjects; and

(iii) determining, with the one or more processors, blood composition-indicative information based on the comparison of the determined ratio and the reference ratio.

12. The method of claim 10, wherein the one or more sensors are disposed at a predetermined distance away from the subject, the predetermined distance being at least one decimeter.

13. The method of claim 10, wherein the at least two color channels are associated with a color model, the color model being based on a color model convention allocating respective wavelength portions to the at least two color channels, the color model is a color space based on a color space mapping convention, respective wavelength portions are assigned to respective axes of the color space, and the color space is an additive color space composed of three color channels.

14. The method of claim 10, further comprising:

determining, with the one or more processors,

(i) a level of bilirubin accumulated in the subject'"'"'s dermis based on constant or quasi-constant channel signal strengths, and

(ii) (ii) an estimate of a serum bilirubin level compared to a skin-bilirubin level.

15. The method of claim 10, further comprising:

determining, with the one or more processors, relative channel signal strength information indicative of impending suffocation.

16. The method of claim 15, further comprising:

(i) determining, with the one or more processors, oxygenation information based on a ratio of the detected channel signal strengths, the oxygenation information being indicative of a ratio of hemoglobin and oxyhemoglobin in the subject'"'"'s blood; and

(ii) outputting an alert signal responsive to the ratio exceeding a reference threshold.

17. The method of claim 10, further comprising:

detecting, with the one or more processors, at least one indicative skin portion of the subject based on the skin radiation information.

18. The method of claim 10, further comprising:

(i) emitting, with a treating radiation source, radiation in a particular wavelength range, wherein the treating radiation source is disposed such that the emitted radiation is directed to the subject, and

(ii) controlling, with the one or more processors, operation of the treating radiation source based on the determined blood composition-indicative information of the subject.