SYSTEM AND/OR METHOD FOR GLUCOSE SENSOR CALIBRATION

• US 20120108933A1
• Filed: 09/21/2011
• Published: 05/03/2012
• Est. Priority Date: 10/28/2010
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Liang, Bradley, Cooper, Kenneth W., Gautham, Raghavendhar, Shah, Rajiv, Nogueira, Keith
• Granted Patent: US 9,402,569 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives

Abstract

The subject matter disclosed herein relates to systems, methods and/or devices for calibrating sensor data to be used in estimating a blood glucose concentration. A relationship between sensor signal values and reference readings may be used to estimate a relationship between sensor signal values and measurements of blood glucose concentration.

Claims

1. A method comprising:

obtaining a sequence of blood glucose reference measurements from a patient; and

deriving a non-linear mapping between sensor signal values and measurements of blood glucose concentration in said patient based, at least in part, on temporal pairings of at least some of said blood glucose reference measurements with said sensor signal values.

2. The method of claim 1, wherein said deriving said non-linear mapping further comprises deriving a piece-wise function comprising at least one linear portion and at least one non-linear portion.

3. The method of claim 2, wherein said non-linear portion is derived according to a polynomial expression.

4. The method of claim 3, and further comprising determining coefficients of terms in said polynomial expression based, at least in part, on said temporal pairings.

5. The method of claim 2, wherein said non-linear portion is derived according to an exponential expression.

6. The method of claim 5, and further comprising determining parameters of said exponential expression based, at least in part, on said temporal pairings.

7. The method of claim 2, and further comprising, for values in said non-linear portion, obtaining a measurement of blood glucose concentration by applying an offset to a function defining said linear portion.

8. The method of claim 1, wherein said non-linear mapping comprises a cubic function, and wherein said deriving said non-linear mapping further comprises determining coefficients of said cubic function.

9. An apparatus comprising:

a sensor to generate signal values responsive to a blood glucose concentration in a body; and

a special purpose computing apparatus to;

obtain a sequence of blood glucose reference measurements taken from said body; and

derive a non-linear mapping between said signal values and measurements of blood glucose concentration in said body based, at least in part, on temporal pairings of at least some of said blood glucose reference measurements with said signal values.

10. The apparatus of claim 9, wherein said non-linear mapping is derived by deriving a piece-wise function comprising at least one linear portion and at least one non-linear portion.

11. The apparatus of claim 10, wherein said special purpose computing apparatus to further obtaining a measurement of blood glucose concentration by applying an offset to a function defining said linear portion for values in said non-linear portion.

12. The apparatus of claim 9, wherein said non-linear mapping comprises a cubic function, and wherein said non-linear mapping is derived, at least in part, by determining coefficients of said cubic function.

13. An article comprising:

a non-transitory storage medium having machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to;

obtain a sequence of blood glucose reference measurements taken from a body; and

derive a non-linear mapping between sensor signal values and measurements of blood glucose concentration in said body based, at least in part, on temporal pairings of at least some of said blood glucose reference measurements with said sensor signal values.

14. The article of claim 13, wherein said non-linear mapping is derived by deriving a piece-wise function comprising at least one linear portion and at least one non-linear portion.

15. The article of claim 14, wherein said instructions are further executable by said special purpose computing apparatus to obtain a measurement of blood glucose concentration by applying an offset to a function defining said linear portion for values in said non-linear portion.

16. The article of claim 13, wherein said non-linear mapping comprises a cubic function, and wherein said non-linear mapping is derived, at least in part, by determining coefficients of said cubic function.

17. An apparatus comprising:

means for obtaining a sequence of blood glucose reference measurements from a body; and

means for deriving a non-linear mapping between sensor signal values and measurements of blood glucose concentration in said body based, at least in part, on temporal pairings of at least some of said blood glucose reference measurements with said sensor signal values.

18. The apparatus of claim 17, wherein said means for deriving said non-linear mapping further comprises means for deriving a piece-wise function comprising at least one linear portion and at least one non-linear portion.

19. The apparatus of claim 18, wherein said non-linear portion is derived according to an exponential expression.

20. The apparatus of claim 19, and further comprising means for determining parameters of said exponential expression based, at least in part, on said temporal pairings.