EQUILIBRIUM NON-CONSUMING FLUORESCENCE SENSOR FOR REAL TIME INTRAVASCULAR GLUCOSE MEASUREMENT

• US 20090018418A1
• Filed: 05/09/2008
• Published: 01/15/2009
• Est. Priority Date: 05/10/2007
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: GluMetrics, Inc.
• Inventors: Markle, William, Markle, David R.
• Granted Patent: US 8,738,107 B2
• Time in Patent Office: Days
• US Class Current: 600/317
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/14735 comprising an immobilised reagent

Abstract

Embodiments of the present invention relates to analyte sensors. In particular, the preferred embodiments of the present invention relate to non-consuming intravascular glucose sensors based on fluorescence chemistry.

Claims

1. An intravascular sensor for determining an analyte concentration in blood comprising:

an optical fiber comprising a sensor chemistry portion capable of insertion into a blood vessel, the sensor chemistry portion comprising;

an analyte binding molecule capable of binding an analyte; and

a fluorophore associated with the analyte binding molecule, the fluorophore having a first fluorescence when the analyte binding molecule is not bound to the analyte and a second fluorescence when the analyte binding molecule is bound to the analyte;

a light source; and

a detector.

2. The sensor of claim 1, wherein the first fluorescence is a first fluorescence intensity and the second fluorescence is a second fluorescence intensity.

3. The sensor of claim 1, wherein the first fluorescence is a first fluorescence lifetime and the second fluorescence is a second fluorescence lifetime.

4. The sensor of claim 1, wherein the analyte is glucose.

5. The sensor of claim 1, further comprising an optical fiber.

6. The sensor of claim 1, wherein the light source is a laser.

7. The sensor of claim 1, wherein the light source is a light emitting diode.

8. The sensor of claim 1, wherein the sensor chemistry portion further comprises a hydrogel that substantially immobilizes the analyte binding molecule and the fluorophore and is permeable to the analyte.

9. The sensor of claim 1, wherein the sensor chemistry portion further comprises a membrane wherein the analyte binding molecule and the fluorophore are substantially retained within a volume at least partially enclosed by the membrane.

12. A method for determining the glucose concentration in blood comprising:

providing the sensor of claim 1;

inserting the sensor into a blood vessel;

irradiating the fluorophore with an excitation signal;

detecting a fluorescence emission from the fluorophore; and

determining the concentration of glucose.

13. The method of claim 12, wherein the excitation signal is a pulse of light.

14. The method of claim 13, further comprising measuring the decay of the fluorescence emission over time;

and

calculating a fluorescence lifetime.

15. The method of claim 12, wherein the excitation signal is frequency modulated.

16. The method of claim 15, further comprising measuring the phase shift between the fluorescence emission and the excitation signal.

17. The method of claim 16, further comprising calculating a fluorescence lifetime.

18. The method of claim 15, further comprising measuring a modulation ratio;

and

calculating a fluorescence lifetime.

19. The method of claim 12, further comprising measuring the fluorescence intensity of the fluorescence emission.

10. An intravascular sensor for determining an analyte concentration in blood comprising:

a sensor chemistry portion capable of insertion into a blood vessel, the sensor chemistry portion comprising;

an analyte binding molecule capable of binding an analyte; and

a fluorophore associated with the analyte binding molecule, the fluorophore having a first fluorescence intensity when the analyte binding molecule is not bound to the analyte and a second fluorescence intensity when the analyte binding molecule is bound to the analyte;

a light source; and

a detector.

11. An intravascular sensor for determining an analyte concentration in blood comprising:

a sensor chemistry portion capable of insertion into a blood vessel, the sensor chemistry portion comprising;

an analyte binding molecule capable of binding an analyte; and

a fluorophore associated with the analyte binding molecule, the fluorophore having a first fluorescence lifetime when the analyte binding molecule is not bound to the analyte and a second fluorescence lifetime when the analyte binding molecule is bound to the analyte;

a light source; and

a detector.

21. A method for determining the glucose concentration in blood comprising:

providing the sensor of claim 11;

inserting the sensor into a blood vessel;

irradiating the fluorophore with an excitation signal;

detecting a fluorescence emission from the fluorophore; and

determining the concentration of glucose.

20. An intravascular sensor for determining an analyte concentration in blood, comprising an optical fiber comprising a sensor chemistry portion disposed along a distal region of the optical fiber, wherein the sensor chemistry portion is sized and physiologically compatible with residing in a blood vessel, wherein the sensor chemistry portion is selected from equilibrium fluorescence chemistry or lifetime chemistry.