Biosensor Cross-Calibration via Background Current Subtraction

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Solution Overview

Problem

Continuous glucose monitoring (CGM) systems face challenges with inconsistent readings and background artifacts immediately after sensor insertion, requiring a run-in time for stabilization, and have limited operational lifetimes of around 14 days, with a need to extend wear time and improve accuracy.

Innovation Solution

A cross-calibration method involving a first biosensor already inserted into the subject is used to calibrate a second biosensor by measuring currents, predicting and subtracting background currents, and applying correction factors based on historical data to achieve accurate glucose values without relying on blood analyte measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a run-in time is required for sensor stabilization after insertion, then measurement reliability is improved, but loss of time increases

Engineering Contradiction:

Improvemeasurement reliabilityVSAvoidrun-in time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary calibration actions during the run-in period by continuously comparing measurements from the first sensor with reference measurements from a second sensor. This preliminary calibration establishes correction factors that can be applied to subsequent measurements, effectively preparing the system for reliable operation without requiring a separate calibration step after the run-in period.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by continuously monitoring the difference between measurements from the first sensor and reference measurements from the second sensor during the run-in period. This feedback is used to dynamically adjust and refine correction factors, ensuring that the calibration adapts to actual sensor behavior and improves measurement reliability over time.

Inventive Principle:

Principle #23Feedback

2Productivity

If sensor wear time is extended beyond traditional limits, then productivity is improved, but measurement precision deteriorates due to drift and artifacts

Engineering Contradiction:

Improvesensor wear timeVSAvoidmeasurement accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system continuously compares measurements from the first sensor with reference measurements from the second sensor throughout the extended wear period. This ongoing feedback allows the system to detect and correct for sensor drift and background artifacts that develop over time, maintaining measurement precision even as the sensor remains in use for extended periods beyond traditional 14-day limits.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts correction factors based on changing sensor characteristics over time. By monitoring measurement differences and updating calibration parameters continuously, the system adapts to parameter changes in sensor performance, enabling extended wear time while compensating for drift through real-time parameter adjustments.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If cross-calibration is performed without blood analyte measurements, then ease of operation is improved, but measurement precision may be affected

Engineering Contradiction:

Improvecalibration simplicityVSAvoidcalibration accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system uses a second sensor as an intermediary reference device to perform cross-calibration without requiring direct blood analyte measurements. The second sensor provides reference measurements that serve as a mediator between the first sensor and ground truth, enabling calibration to proceed through sensor-to-sensor comparison rather than requiring invasive blood sampling, thus improving ease of operation while maintaining precision through the intermediary reference.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method enables reliable and extended glucose monitoring by stabilizing sensor readings and improving accuracy, potentially extending sensor wear time beyond 30 days with reduced need for blood calibrations.

Implementation Method 1

measuring a first current from a first biosensor and measuring a second current from a second biosensor

Methodology Applied

Scientific EffectElectrochemical measurement:

Data Source

PatentUS20230027609A1Systems and methods for biosensor cross-calibration

Publication Date: 2023.01.26 KONAMITE LTD

AI summary

Embodiments provide for methods, systems, apparatus and computer readable media for calibrating an analyte sensor upon insertion into tissue of a subject based at least in part on parameters obtained from another analyte sensor already calibrated and previously inserted into the tissue of the subject. As an example, a method may include predicting a background current associated with the newly inserted sensor, subtracting the background current from a current measured by the newly inserted sensor, and converting the subtracted current to a glucose value, the converting based at least in part on the parameters obtained from the previously inserted analyte sensor. In this way, the newly inserted sensor may be calibrated without relying on actual blood-based analyte measurements, and accuracy and sensitivity of the newly inserted sensor may be improved.