Optical systems and methods for ratiometric measurement of blood glucose concentration

• US 9,839,378 B2
• Filed: 08/07/2014
• Issued: 12/12/2017
• Est. Priority Date: 02/06/2007
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Markle, David R., Wessling, Ritchie A., Kolehmainen, Donald J.
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Fardanesh, Marjan
• Application Number:
  US14/454,568
• Publication Number:
  US 20140350364A1
• Time in Patent Office: 1,223 Days
• Field of Search: None
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: G01N 21/6428 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 Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters

Abstract

Novel optical devices, methods and systems relating to the detection of glucose, and more particularly to real-time glucose monitoring, are disclosed herein. More particularly, various hardware and methodological means are disclosed for ratiometric correction of optical glucose measurements for artifacts of optical systems.

Claims

1. An optical device for determining blood glucose concentration, comprising:

at least one excitation light source that emits at least one excitation light signal;

a fiber optic sensor optically coupled to the at least one excitation light source and comprising an indicator system comprising a fluorophore operably coupled to a glucose binding moiety, wherein upon absorption of at least a portion of the at least one excitation light signal, the indicator system emits at least a first emission light signal and a second emission light signal, wherein the first and second emission light signals are each related to glucose concentration, and wherein a ratio of the first and second emission light signals is glucose insensitive and the ratio is related to pH levels; and

a detector system operably coupled to at least the sensor, wherein the detector system is adapted to detect the first and second emission light signals.

2. The optical device of claim 1, wherein the detector system further comprises a microspectrometer adapted to detect the emission light signals.

3. The optical device of claim 1, wherein the detector system further comprises at least two light detectors adapted to detect the first and second emission light signals.

4. The optical device of claim 1, further comprising a data processing device in communication with the detector system, wherein the data processing device determines the blood glucose concentration substantially corrected for artifacts of the optical device unrelated to the blood glucose concentration by performing a ratiometric analysis of the emission light signals.

5. The optical device of claim 4, wherein the data processing device further determines the pH levels using the ratio of the first emission light signal and the second emission light signal.

6. The optical device of claim 1, wherein the first emission light signal is produced from an acid form of the fluorophore and the second light signal is produced from the base form of the fluorophore.

7. The optical device of claim 1, wherein the at least one excitation light source includes a first excitation light source that emits a first excitation light signal and a second excitation light source that emits a second excitation light signal.

8. The optical device of claim 7, wherein the second excitation light signal is at a different wavelength than the first excitation light signal.

9. The optical device of claim 7, wherein the first emission light signal is produced from an acid form of the fluorophore and the second light signal is produced from the base form of the fluorophore.

10. The optical device of claim 9, wherein the optical device further comprises a first interference filter between the first excitation light source and the fiber optic sensor.

11. The optical device of claim 10, wherein the first interference filter ensures that the first excitation light source excites only the acid form of the fluorophore.

12. The optical device of claim 9, wherein the optical device further comprises a second interference filter between the second excitation light source and the fiber optic sensor.

13. The optical device of claim 1, wherein the fluorophore is HPTS-TriCys-MA.

14. The optical device of claim 1, wherein the indicator system comprises a second fluorophore.