Accuracy of Continuous Glucose Sensors

Abstract

A method, apparatus, and a kit are capable of improving accuracy of CGS devices using dynamic outputs of continuous glucose sensors.

Description

CROSS-REFERENCE TO RELATED PUBLICATIONS[0001]This US patent application claims priority under 35 U.S.C. 119(e) from co-pending U.S. provisional application Ser. No. 60 / 713,203 filed Aug. 31, 2005, and Ser. No. 60 / 815,191 filed Jun. 20, 2006, the subject matter of each being incorporated herein by reference in its entirety. The subject matter of each one of the publications and the US provisional application in APPENDIX A attached herewith is incorporated herein by reference in their entirety.TECHNICAL FIELD OF THE INVENTION[0002]The present invention relates to the art of glucose monitoring, and more particularly to methods and systems for continuous glucose monitoring.BACKGROUND OF THE INVENTION[0003]Existing evidence, such as “National Diabetes Fact Sheet” by American Diabetes Association, indicates that currently approximately 18.2 million people in the U.S. have diabetes; and diabetes is the sixth-leading cause of death in the U.S. One in three Americans born in the year 2000 wi...

AI Technical Summary

Benefits of technology

The present invention improves the accuracy and reliability of CGS by calibrating CGS sensors or remedying errors due to physiological time lag or a combination thereof. The invention provides methods for improving accuracy of CGS by calibrating CGS at a first time and changing the CGS calibration at a second time based upon a dynamically monitored CGS value, a rate of CGS change, and a predetermined criterion. The invention also provides a computer-readable medium and a system for treating a disease associated with blood glucose. The technical effects of the invention include improved accuracy and reliability of CGS, dynamic calibration for CGS, and improved disease treatment.

Problems solved by technology

Most contemporary continuous glucose sensors (hereafter CGS), however, yield blood glucose (hereafter BG) estimates by sampling interstitial glucose (hereafter IG) in interstitial fluid, rather than BG due to the difficulty in directly measuring BG in artery or blood vessels.

As a result, although CGS technology has made dramatic strides, the development of accurate and reliable CGS devices continues to face numerous challenges in terms of calibration, sensitivity, stability, and physiological time lag between blood and interstitial glucose concentrations.

The physiological time lag and gradients are changing dynamically with time, with BG levels, and across subjects; and the direct frequent in vivo sampling of IG is extremely difficult.

Consequently, the evaluation of engineering performance of CGS is left with a central problem: separating the portion of BG / CGS error due to calibration, sensor noise, and BG / IG gradient.

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