Monitoring of physiological analytes

• US 20070142721A1
• Filed: 01/30/2007
• Published: 06/21/2007
• Est. Priority Date: 05/13/1998
• Status: Active Grant

• Current Assignee: LifeScan IP Holdings, LLC
• Original Assignee: Bret Berner, Chia-Ming Chiang, Janan Jona, Janet Tamada, Michael Garrison, Michael Tierney, Russell Potts
• Inventors: Berner, Bret, Chiang, Chia-Ming, Jona, Janan, Tamada, Janet, Garrison, Michael, Tierney, Michael, Potts, Russell
• Granted Patent: US 7,873,399 B2
• Time in Patent Office: Days
• US Class Current: 600/347
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150091 by electricity
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61N 1/30 Apparatus for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body, or cataphoresis
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

Methods and devices are provided for measuring the concentration of target chemical analytes present in a biological system. Device configuration and/or measurement techniques are employed in order to reduce the effect of interfering species on sensor sensitivity. One important application of the invention involves a method and device for monitoring blood glucose values.

Claims

1. A monitoring system for measuring an amount or concentration of an analyte present in one or more samples in a biological system, the monitoring system comprising:

a sampling device for providing one or more samples comprising said analyte, wherein said sampling device comprises one or more microneedles or microfine cannulas;

a sensing device adapted to obtain a measurement signal from the analyte in each of said samples, said measurement signal specifically related to the analyte amount or concentration in the biological system; and

one or microprocessors in operative communication with said sensing device, wherein said one or more microprocessors comprise programming to control (i) operating said sensing device to provide said measurement signals, (ii) applying one or more processes for selectively favoring analyte-specific signal components over other signal components due to interfering species, said processes selected from the group consisting of (a) a differential signal process which subtracts non-analyte signal components from the measurement signal, (b) a selective detection process which is performed during sensing, (c) a purge step that is performed before and/or after said obtaining, wherein said purge step substantially removes residual signal components from the sensing device, and (d) any combinations thereof, and (iii) repeating steps (i) and (ii) at least once over time.

2. The monitoring system of claim 1, wherein said one or more microprocessors are in operative communication with said sampling device and said one or more microprocessors further comprise programming to control operating said sampling device.

3. The monitoring system of claim 1, wherein said sampling device further comprises one or more collection reservoirs.

4. The monitoring system of claim 3, wherein said one or more collection reservoirs comprise miniaturized etched, ablated or molded flow paths.

5. The monitoring system of claim 1, wherein the analyte is glucose.

6. The monitoring system of claim 1, wherein said sensing device comprises a sensing electrode.

7. The monitoring system of claim 6, wherein said sensing electrode is in operative contact with at least one of said one or more collection reservoirs.

8. A monitoring system for measuring an amount or concentration of an analyte present in one or more samples in a biological system, the monitoring system comprising:

a sampling device for providing one or more samples comprising said analyte, wherein said samples are provided using iontophoresis;

a sensing device adapted to obtain a measurement signal from the analyte in each of said samples, said measurement signal specifically related to the analyte amount or concentration in the biological system; and

one or microprocessors in operative communication with said sensing device, wherein said one or more microprocessors comprise programming to control (i) operating said sampling device (ii) operating said sensing device to provide said measurement signals, (iii) applying one or more processes for selectively favoring analyte-specific signal components over other signal components due to interfering species, said processes selected from the group consisting of (a) a differential signal process which subtracts non-analyte signal components from the measurement signal, (b) a selective detection process which is performed during sensing, (c) a purge step that is performed before and/or after said obtaining, wherein said purge step substantially removes residual signal components from the sensing device, and (d) any combinations thereof, and (iv) repeating steps (i) through (iii) at least once over time.

9. The monitoring system of claim 8, wherein the sampling device also comprises microneedles for pretreatment of the sample site.

10. The monitoring system of claim 8, further comprising a laser for pretreatment of the sample site.

11. The monitoring system of claim 8, wherein said sampling device further comprises one or more collection reservoirs.

12. The monitoring system of claim 11, wherein said one or more collection reservoirs comprise miniaturized etched, ablated or molded flow paths.

13. The monitoring system of claim 8, wherein the analyte is glucose.

14. The monitoring system of claim 8, wherein said sensing device comprises a sensing electrode.

15. The monitoring system of claim 14, wherein said sensing electrode is in operative contact with at least one of said one or more collection reservoirs.

16. A method for measuring an amount or concentration of an analyte present in one or more samples in a biological system, the method comprising:

pre-treating a sample site to enhance permeability of the sample site;

providing one or more samples comprising said analyte from the sample site, wherein said samples are provided using iontophoresis;

sensing each of said one or more samples with a sensor device;

obtaining respective measurement signals from the analyte in each of said samples based on said sensing, said measurement signals specifically related to the analyte amount or concentration in the biological system; and

providing one or microprocessors in operative communication with said sensor device, wherein said one or more microprocessors comprise programming to control (i) operating said sensing device to provide said measurement signals, (ii) applying one or more processes for selectively favoring analyte-specific signal components over other signal components due to interfering species, said processes selected from the group consisting of (a) a differential signal process which subtracts non-analyte signal components from the measurement signal, (b) a selective detection process which is performed during the sensing, (c) a purge performed before and/or after said obtaining, wherein said purge substantially removes residual signal components from the sensor device, and (d) any combinations thereof, and (iii) repeating steps (i) and (ii) at least once over time.

17. The method of claim 16, wherein said pre-treating is performed with a laser.

18. The method of claim 16, wherein said pre-treating is performed with a plurality of micro-needles 19. The monitoring system of claim 16, wherein the analyte is glucose.