Fiber Optic Sensor Device for Measuring Chromophoric Compounds in Biological Fluid

• US 20080212918A1
• Filed: 02/28/2008
• Published: 09/04/2008
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Babin, Steven M.
• Granted Patent: US 7,508,999 B2
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: G01N 2021/7736 exposed, cladding free
• CPC Class Codes: G01N 2021/7759 Dipstick; Test strip
• CPC Class Codes: G01N 2021/7773 Reflection
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements

Abstract

A fiber optic sensor device for detecting the presence of a chromophoric compound in a biological fluid is disclosed. The fiber optic sensor device includes at least one fiber optic member having an unclad portion, the fiber optic member having a proximal end and a distal end for transmitting light energy of a determinable wavelength, a light source means for generating light energy of determinable wavelength, said light source means operatively associated with a measuring means such that said light energy passes through said measuring means and said fiber optic member to the biological fluid, and measuring means operatively associated with said fiber optic member and said light source, for measuring the difference between said light energy generated by said light source and light reflected from the distal end of the fiber optic member, wherein the difference is related to the light absorbed by the chromophoric compound and indicative of the concentration of the chromophoric compound present in the biological fluid.

Claims

1. A fiber optic sensor device for detecting the presence of a chromophoric compound in a biological fluid is provided comprising:

at least one fiber optic member having an unclad portion, the fiber optic member having a proximal end and a distal end for transmitting light energy of a determinable wavelength,

a light source means for generating light energy of determinable wavelength, said light source means operatively associated with a measuring means such that said light energy passes through said measuring means and said fiber optic member to the biological fluid, and

measuring means operatively associated with said fiber optic member and said light source, for measuring the difference between said light energy generated by said light source and light reflected from the distal end of the fiber optic member, wherein the difference is related to the light absorbed by the chromophoric compound and indicative of the concentration of the chromophoric compound present in the biological fluid.

2. The fiber optic sensor device of claim 1, wherein the chromophoric compound is selected from the group consisting of bilirubin, theophylline and cortisol.

3. The fiber optic sensor device of claim 1, wherein the biological fluid is selected from the group consisting of blood, saliva, sweat, amniotic fluid, urine and tears.

4. The fiber optic sensor device of claim 1, wherein the chromophoric compound is bilirubin or theophylline and the biological fluid is blood.

5. The fiber optic sensor device of claim 1, wherein the light source means is selected from the group consisting of an argon laser, blue laser, tunable laser and light emitting diode.

6. The fiber optic sensor device of claim 1, wherein the measuring means comprises a directional coupler operatively associated with one or more light meters.

7. The fiber optic sensor device of claim 1, wherein a mirror coating is plated at the distal end of the fiber optic member.

8. The fiber optic sensor device of claim 1, wherein the fiber optic member comprises a cladded portion at the proximal end of the fiber optic member and an unclad portion at the distal end of the fiber optic member.

9. The fiber optic sensor device of claim 1, wherein interaction of the chromophoric compound with the light is interactive with an evanescent wave form of the input light.

10. A method for detecting the presence of a chromophoric compound in a biological fluid of a subject, the method comprising the steps of:

(a) providing a fiber optic sensor device comprising;

at least one fiber optic member having an unclad portion, the fiber optic member having a proximal end and a distal end for transmitting light energy of a determinable wavelength,

a light source means for generating light energy of determinable wavelength, said light source means operatively associated with a measuring means such that said light energy passes through said measuring means and said fiber optic member to the biological fluid, and

measuring means operatively associated with said fiber optic member and said light source, for measuring the difference between said light energy generated by said light source and light reflected from the distal end of the fiber optic member, said reflected light being related to the light absorbed by the chromophoric compound;

(b) exposing the fiber optic member having an unclad portion of the fiber optic sensor device to an environment containing the biological fluid, and

(c) measuring the difference between said light energy generated by said light source of the fiber optic sensor device and the light reflected from the distal end of the fiber optic member, said measurement being indicative of the concentration of the chromophoric compound present in the biological fluid.

11. The method of claim 10, wherein the chromophoric compound is selected from the group consisting of bilirubin, theophylline and cortisol.

12. The method of claim 10, wherein the biological fluid is selected from the group consisting of blood, saliva, sweat, amniotic fluid, urine and tears.

13. The method of claim 10, wherein the chromophoric compound is bilirubin or theophylline and the biological fluid is blood.

14. The method of claim 10, wherein the light source means is selected from the group consisting of an argon laser, blue laser, tunable laser, and light emitting diode.

15. The method of claim 10, wherein the measuring means comprises a directional coupler operatively associated with one or more light meters.

16. The method of claim 10, wherein a mirror coating is plated at the distal end of the fiber optic member.

17. The method of claim 10, wherein the fiber optic member comprises a cladded portion at the proximal end of the fiber optic member and an unclad portion at the distal end of the fiber optic member.

18. The method of claim 10, wherein interaction of the chromophoric compound with the light is interactive with an evanescent wave form of the input light.

19. The method of claim 10, wherein the step of exposing the fiber optic member to an environment containing the biological fluid comprises inserting the unclad portion of the fiber optic member into the bloodstream of the subject.

20. The method of claim 10, wherein the wherein the step of exposing the fiber optic member to an environment containing the biological fluid comprises contacting the amniotic sac of the subject with the unclad portion of the fiber optic member.