Determining a presence of auto-fluorescent biological substances through an article

Patent metadata

Field	Value
Publication number	US-11389339-B2
Application number	US-201916542898-A
Country	US
Kind code	B2
Filing date	Aug 16, 2019
Priority date	Aug 16, 2019
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

Techniques are disclosed for detecting a presence of a biological substance through an article such as a diaper. For example, a detection system causes a light source to transmit light through the article. The light includes a peak wavelength that corresponds to an excitation wavelength of a biological substance that may be present in the article. The detection system detects a measurement of light intensity within a range of emission wavelengths of the biological substance. By comparing the measurement of light intensity to a threshold, the detection system identifies a presence of the biological substance on the article.

First claim

That which is claimed is:

1. A method comprising:
causing, at a first time, a first light source to transmit, through an article, light that includes a first peak wavelength that corresponds to a first excitation wavelength of a biological substance, the biological substance comprising multiple excitation wavelengths;
detecting a first measurement of light intensity within a first range of emission wavelengths of the biological substance;
causing, at a second time, a second light source to transmit, through the article, light that includes a second peak wavelength that corresponds to a second excitation wavelength of the biological substance, wherein the first peak wavelength is different from the second peak wavelength;
detecting a second measurement of light intensity within a second range of emission wavelengths of the biological substance; and
responsive to comparing a ratio of the first measurement of light intensity and the second measurement of light intensity against a threshold, identifying a presence of the biological substance on the article.

2. The method of claim 1 , wherein the first excitation wavelength is different from the second peak wavelength.

3. The method of claim 1 , wherein identifying the presence of the biological substance further comprises comparing the first measurement of light intensity to a first threshold and comparing the second measurement of light intensity to a second threshold.

4. The method of claim 1 , wherein identifying the presence of the biological substance further comprises calculating an additional ratio of the first measurement of light intensity to the second measurement of light intensity and comparing the additional ratio to an additional threshold.

5. The method of claim 1 , wherein the first excitation wavelength and the second excitation wavelength are between 405 and 720 nm.

6. The method of claim 1 , wherein the first range of emission wavelengths does not overlap with the second range of emission wavelengths, the first range of emission wavelengths is between 600-720 nm, and the second range of emission wavelengths is between 600-720 nm.

7. The method of claim 1 , wherein the first excitation wavelength is between 380 to 740 nm, the second excitation wavelength is between 380 to 740 nm, and the first range of emission wavelengths and the second range of emission wavelengths are between 600 and 720 nm.

8. The method of claim 1 , wherein the first range of emission wavelengths comprises at least one wavelength in common with the second range of emission wavelengths.

9. The method of claim 1 , further comprising:
obtaining a baseline measurement of light intensity, the baseline measurement of light intensity comprising a contribution of ambient light; and
removing, from the first measurement of light intensity and from the second measurement of light intensity, the baseline measurement of light intensity.

10. A method comprising:
causing a light source to transmit, through an article, light that includes a peak excitation wavelength that corresponds to an excitation wavelength of a biological substance;
detecting a measurement of light intensity within a first range of emission wavelengths of the biological substance, wherein the biological substance has multiple emission wavelengths and wherein the first range of emission wavelengths has a first peak emission wavelength;
detecting an additional measurement of light intensity within a second range of emission wavelengths of the biological substance, wherein the second range of emission wavelengths has a second peak emission wavelength that is different than the first peak emission wavelength; and
responsive to comparing the measurement of light intensity against a threshold and comparing the additional measurement of light intensity against an additional threshold, identifying a presence of the biological substance on the article.

11. The method of claim 10 , wherein the peak excitation wavelength is between 405 and 650 nm, the first range of emission wavelengths is either 620 to 640 nm or 650 to 710 nm, and the second range of emission wavelengths is either 620 to 640 nm or 650 to 710 nm.

12. The method of claim 10 , wherein the biological substance is a porphyrin.

13. A system comprising:
a first light source configured to emit light that includes a first peak wavelength that corresponds to a first excitation wavelength of a biological substance;
a second light source configured to emit light that includes a second peak wavelength that corresponds to a second excitation wavelength of the biological substance, wherein the first peak wavelength is different from the second peak wavelength;
a photodetector configured to measure an intensity of light within a range of emission wavelengths of the biological substance; and
a processor configured to perform operations comprising:
cause the first light source to transmit light through an article at a first time;
detect a first measurement of light intensity at the photodetector at a second time that is different from the first time;
cause the second light source to transmit light through the article at a third time different from the second time;
detect a second measurement of light intensity at the photodetector at a fourth time different from the third time; and
responsive to comparing a ratio of the first measurement of light intensity and the second measurement of light intensity against a threshold, identifying a presence of the biological substance on the article.

14. The system of claim 13 , further comprising:
a first light filter coupled to the first light source;
a second light filter coupled to the second light source; and
a third light filter coupled to the photodetector.

15. The system of claim 13 , wherein the first peak wavelength and the second peak wavelength are between 380 and 720 nm.

16. The system of claim 13 , wherein the range of emission wavelengths is either 620 to 640 nm or 650 to 710 nm.

17. The system of claim 13 , wherein the first excitation wavelength and the second excitation wavelength are between 380 to 740 nm and the range of emission wavelengths 600 to 720 nm.

18. The system of claim 13 , wherein identifying the presence of the biological substance further comprises:
comparing the first measurement of light intensity to a first threshold;
comparing the second measurement of light intensity to a second threshold; and
calculating an additional ratio of the first measurement of light intensity to the second measurement of light intensity and comparing the ratio to a third threshold.

19. The system of claim 13 , wherein the operations further comprise:
obtaining, from the photodetector, a baseline measurement of light intensity, the baseline measurement of light intensity comprising a contribution of ambient light; and
removing, from the first measurement of light intensity and from the second measurement of light intensity, the baseline measurement of light intensity.

20. The system of claim 13 , wherein the second measurement of light intensity and the first measurement of light intensity represent non-overlapping ranges of wavelengths.

21. The method of claim 10 , wherein the first range of emission wavelengths and second range of emission wavelengths are either 620 to 640 nm or 650 to 710 nm.

Assignees

• Verily Life Sciences Llc

Inventors

• Schiffer Brian

Classifications

• G01N21/6428

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title

• A61F13/42 Primary

  with wetness indicator or alarm · CPC title

• G01N21/6486

  Measuring fluorescence of biological material, e.g. DNA, RNA, cells (G01N21/6428 takes precedence) · CPC title

• A61F2013/8491

  including test methods · CPC title

• G01N2021/6421

  Measuring at two or more wavelengths · CPC title