APPARATUS AND METHOD FOR MEASURING AN ANALYTE SUCH AS BILIRUBIN, USING LIGHT

• US 20130057865A1
• Filed: 04/27/2011
• Published: 03/07/2013
• Est. Priority Date: 05/27/2010
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Meijer, Eduard Johannes, Kudavelly, Srinivas Rao
• Granted Patent: US 9,279,763 B2
• Time in Patent Office: Days
• US Class Current: 356/416
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: G01N 2021/3144 for oxymetry
• CPC Class Codes: G01N 2021/3148 using three or more wavelengths
• CPC Class Codes: G01N 2021/3177 Use of spatially separated filters in simultaneous way
• CPC Class Codes: G01N 2021/3181 using LEDs
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/49 within a body or fluid
• CPC Class Codes: G01N 2201/0627 Use of several LED's for spectral resolution
• CPC Class Codes: G01N 2201/0826 Fibre array at source, distributing

Abstract

An analyte measuring device (5) for monitoring, for example, levels of a tissue analyte (e.g., bilirubin), includes a number of narrow band light sources (10), each narrow band light source being structured to emit a spectrum of light covering a number of wavelengths, and a number of detector assemblies (15) configured to receive light reflected from the transcutaneous tissues of a subject. Each of the detector assemblies includes a filter (20) and a photodetector (25), each filter being structured to transmit a main transmission band and one or more transmission sidebands, wherein for each narrow band light source the spectrum thereof includes one or more wavelengths that fall within the transmission band of at least one of the filters, and wherein for each narrow band light source the spectrum thereof does not include any wavelengths that fall within the one or more transmission sidebands of any of the optical filters.

Claims

1. An analyte measuring device (5), comprising:

a number of narrow band light sources (10), each narrow band light source being structured to emit a spectrum of light covering a number of wavelengths; and

a number of detector assemblies (15) configured to receive light reflected from a subject, each of the detector assemblies including a filter (20) and a photodetector (25), each filter being structured to transmit a main transmission band and one or more transmission sidebands, wherein for each narrow band light source the spectrum thereof includes one or more wavelengths that fall within the transmission band of at least one of the filters, and wherein for each narrow band light source the spectrum thereof does not include any wavelengths that fall within the one or more transmission sidebands of any of the filters.

2. The measuring device according to claim 1, wherein the number of detector assemblies is a plurality of detector assemblies.

3. The measuring device according to claim 2, wherein the subject is a human and wherein the analyte is a tissue analyte.

4. The measuring device according to claim 3, wherein the tissue analyte is bilirubin, wherein the number of detector assemblies are configured to receive light reflected from transcutaneous tissues of the subject, and wherein the main transmission bands of the filters of the plurality of detector assemblies include a plurality of predetermined wavelengths required for determining one or both of a TCB level and a TSB level of the subject.

5. The measuring device according to claim 2, wherein the number of narrow band light sources is a plurality of narrow band light sources.

6. The measuring device according to claim 5, wherein each filter is centered at a predetermined wavelength of light and has a predetermined full-width at half maximum.

7. The measuring device according to claim 6, wherein the plurality of narrow band light sources includes a first narrow band light source comprising a cyan LED and a second narrow band light source comprising a green LED, and wherein the filters of the detector assemblies includes a first filter centered at 484.22 nm with a FWHM of 5.60714 nm, a second filter centered at 517.61 nm with a FWHM of 6.74956 nm, and a third filter centered at 564.19 nm with a FWHM of 7.35165 nm.

8. The measuring device according to claim 6, wherein each filter is an all-dielectric interference filter stack.

9. The measuring device according to claim 4, further comprising a controller (30) operatively coupled to the number of narrow band light sources and the number of detector assemblies, wherein each photodetector is structured to convert light received thereby to an electrical signal, and wherein the controller is adapted to determine one or both of a TCB level and a TSB level of the subject based on the electrical signal received from each photodetector.

10. The measuring device according to claim 1, wherein each photodetector is a photodiode.

11. The measuring device according to claim 4, wherein the number of detector assemblies is shielded from all light except the light reflected from the transcutaneous tissues of the subject.

13. The method according to claim 11, wherein the analyte is a tissue analyte of the subject, wherein the directing comprises directing light from the number of light sources toward the skin of the subject, and wherein in response to the directing, the reflected light is reflected by transcutaneous tissues of the subject.

14. The method according to claim 13, wherein the tissue analyte is bilirubin and the method is a method of estimating a bilirubin level of the subject, wherein the determining a measurement relating to the analyte comprises determining an estimated bilirubin level based on the filtered light associated with each filter

16. The method according to claim 14, wherein the number of filters is a plurality of filters, and wherein the main transmission bands of the filters include a plurality of predetermined wavelengths required for determining one or both of a TCB level and a TSB level of the subject.

21. The method according to claim 14, further comprising converting each filtered light to an electrical signal, wherein the determining an estimated bilirubin level comprises determining one or both of a TCB level and a TSB level of the subject based on the electrical signal associated with each filtered light.

12. A method of measuring an analyte of a subject, comprising:

directing light from a number of light sources (10) toward the subject, each light source emitting a spectrum of light covering a number of wavelengths, wherein in response to the directing, reflected light is reflected by the subject;

filtering the reflected light using a number of filters (20), each filter being structured to transmit a main transmission band and one or more transmission sidebands, wherein for each light source the spectrum thereof includes one or more wavelengths that fall within the transmission band of at least one of the filters, and wherein for each light source the spectrum thereof does not include any wavelengths that fall within the one or more transmission sidebands of any of the filters, the filtering producing a filtered light associated with each filter; and

determining a measurement relating to the analyte based on the filtered light associated with each filter.

15. The method according to claim 12, wherein the number of filters is a plurality of filters.

17. The method according to claim 15, wherein the number of sources is a plurality of light sources.

18. The method according to claim 17, wherein each filter is centered at a predetermined wavelength of light and has a predetermined full-width at half maximum.

19. The method according to claim 18, wherein the plurality of light sources includes a first light source emitting cyan light and a second light source emitting green light, and wherein the filters include a first filter centered at 484.22 nm with a FWHM of 5.60714 nm, a second filter centered at 517.61 nm with a FWHM of 6.74956 nm, and a third filter centered at 564.19 nm with a FWHM of 7.35165 nm.

20. The method according to claim 18, wherein each filter is an all-dielectric interference filter stack.

22. The method according to claim 12, further comprising shielding the number of filters from all light except the reflected light.