Transmission fluorometer

• US 8,594,758 B2
• Filed: 07/12/2012
• Issued: 11/26/2013
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: William Paseman
• Original Assignee: William Paseman
• Inventors: Paseman, Sabrina K., Paseman, William G.
• Primary Examiner(s): Perkey, W B
• Application Number:
  US13/547,906
• Publication Number:
  US 20120277555A1
• Time in Patent Office: 502 Days
• Field of Search: 600/322
• US Class Current: 600/322
• 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 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• 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 5/6825 Hand

Abstract

This disclosure relates generally to a system and method for noninvasive, non-destructive fluorescent measurement. More specifically, the disclosure provides a non-invasive metrology system and method to monitor levels of fluorescent chemicals in the blood. A major application for the invention is field-based non-invasive blood testing for micro-nutrient deficiency and diseases resulting from it, such as Iron deficient anemia. The invention may help reduce or eliminate the need for blood drawing, sending the sample to a blood lab and having to wait for a result.

Claims

1. A non-invasive measurement system for determining ratios of concentrations of at least two analytes in a sample area, the system comprising:

a light source configured to provide an output spectrum which excites the at least two analytes at each of a plurality of discrete locations within a sample area;

an image sensing assembly capable of sensing the intensity and wavelength of fluoresced light emitted by the at least two analytes upon excitation by the light source at each of the plurality of discrete locations within the sample area; and

a computer system linked to the image sensing assembly, the computer system comprising computer readable code for computing and providing as output the ratio of the concentration of one analyte relative to the concentration of at least another analyte for each of the plurality of discrete locations within the sample area.

2. The system of claim 1, further comprising receiving optics positioned relative to the light source so as to receive the fluoresced light, the receiving optics being coupled to the image sensing assembly.

3. The system of claim 1, wherein the output comprises a graphical representation of the sample area.

4. The system of claim 1, wherein the image sensing assembly comprises a charge coupled device array.

5. The system of claim 1, further comprising at least two filters, each filter corresponding to an emission wavelength of one of the at least two analytes.

6. The system of claim 5, wherein the at least two filters are arranged so that the filters may be successively placed between the light source and the image sensing assembly.

7. The system of claim 1, wherein the light source comprises an LED, laser diode or monochromator.

8. The system of claim 1, wherein the light source emits a wavelength chosen from the ranges of about 346 to about 370 nm, about 390 to about 400 nm and about 420 to about 430 nm.

9. The system of claim 1, wherein the light sources emits wavelengths that excite micro-nutrients.

10. The system of claim 2, further comprising a source-receiver assembly configured to maintain optical alignment between the light source and the receiving optics, whereby the sample is pinched between the light source and the receiving optics.

11. The system of claim 2, further comprising a sample holding device configured to hold the sample in a source-receiver assembly between the light source and the receiving optics.

12. The system of claim 11, wherein the sample holding device is configured to pinch a sample to a thickness consistent with measurements at wavelengths chosen from the ranges of about 346 to about 370 nm, about 390 to about 400 nm and about 420 to about 430 nm.

13. The system of claim 10, wherein the source-receiver assembly is configured to receive feedback from the computer to support automatic control of the light source.

14. The system of claim 1, wherein the computer readable code comprises instructions for employing absorption-based analyte identification algorithms to detect non-fluorescing analytes.

15. The system of claim 1, wherein the computer readable code comprises instructions for employing analyte identification algorithm to detect fluorescing analytes.

16. The system of claim 1, wherein the light source comprises multiple LEDs, each LED emitting light over a different range of wavelengths.

17. The system of claim 2, wherein the receiving optics are positioned at an angle of about 180°

relative to the light source.

18. The system of claim 2, wherein the receiving optics are positioned at an angle of greater than 90°

relative to the light source.

19. The system of claim 1, wherein the computer readable code comprises instructions for computing the ratios of heights of multiple emission peaks to determine the ratio of the concentration of one analyte to the concentration of another analyte.

20. The system of claim 1, wherein the computer readable code comprises instructions for computing the ratio of one set of excitation and emission peaks to the ratio of another set of excitation and emission peaks to determine the ratio of the concentration of one analyte to the concentration of another analyte.

21. The system of claim 1, wherein the image sensing assembly is further capable of sensing an unabsorbed portion of the output spectrum provided by the light source.

22. A method for employing the non-invasive system of claim 1, the method comprising:

pinching the sample area into a space between the light source and the image sensing assembly;

applying power to the light source, wherein the power level of the light source is set to a level that causes the image sensing assembly to produce an output;

transmitting the output of the image sensing assembly to the computer system; and

running the at least one program in the computer system.

23. The method of claim 22 wherein the sample area comprises in vivo skin.

24. The method of claim 23 wherein the sample area is the webbing between a patient'"'"'s thumb and forefinger.

25. A method for employing the non-invasive system of claim 10, the method comprising:

applying the source-receiver assembly to the sample area whereby the sample area is pinched between the light source and the receiving optics;

applying power to the light source, wherein the power level of the light source is set to a level that causes the image sensing assembly to produce an output;

transmitting the output of the image sensing assembly to the computer system; and

running the at least one program in the computer system.

26. The method of claim 25 wherein the sample area comprises in vivo skin.

27. The method of claim 26 wherein the sample area is the webbing between a patient'"'"'s thumb and forefinger.

28. The method of claim 22 wherein the sample area is on the patient'"'"'s ear.

29. The method of claim 26 wherein the sample area is on the patient'"'"'s ear.