Analyte Sensor Impedance Measurement for Drift Compensation
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Solution Overview
Problem
Existing analyte sensors face challenges in maintaining accuracy and detecting damage or faults due to in vivo drift and interference, necessitating frequent blood glucose meter calibrations, which are inconvenient and costly.
Innovation Solution
The use of impedance measurements to calibrate and compensate for sensor drift, detect membrane damage, and reduce the need for in vivo calibrations by determining impedance values through electronic measurements, allowing for factory calibration and real-time sensitivity adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If impedance measurements are used to calibrate and compensate for sensor drift, then sensor accuracy is improved and reliance on blood glucose meter calibrations is reduced, but device complexity increases due to additional electronic measurement circuits
Solution Approach 1:
The measurement circuit is designed to perform multiple functions: it measures both the analytical signal from the sensor and the impedance of the sensor membrane. By making the measurement circuit multi-functional, the patent avoids adding separate dedicated impedance measurement circuits, thereby improving sensor accuracy through impedance-based drift compensation while minimizing the increase in device complexity
Solution Approach 2:
The sensor system performs self-calibration and self-diagnosis by using its own impedance characteristics to detect drift and membrane damage. The system automatically adjusts sensitivity parameters based on measured impedance values without requiring external calibration equipment or manual intervention, thereby improving measurement precision while keeping the device architecture relatively simple
2Reliability
If impedance measurements are used to detect membrane damage, then reliability is improved by identifying damaged sensors, but manufacturing precision requirements increase for the electronic measurement circuits
Solution Approach 1:
The system performs preliminary impedance measurements during manufacturing to identify sensors with defective membranes before they reach the customer. By conducting these measurements in advance, the patent ensures that only reliable sensors are deployed, improving overall system reliability while allowing for standard manufacturing tolerances in the electronic circuits since the measurement process itself is well-established
Solution Approach 2:
The measurement circuit continuously monitors sensor impedance and provides feedback about membrane health status. This feedback mechanism enables real-time detection of membrane damage through impedance changes, improving reliability by allowing the system to identify and flag damaged sensors while using standard electronic measurement techniques that do not require ultra-precise manufacturing
3Productivity
If factory calibration is implemented using impedance determination, then productivity is improved by reducing the need for in vivo calibrations, but measurement precision requirements increase for the calibration process
Solution Approach 1:
The patent performs comprehensive sensor calibration and characterization during factory manufacturing using impedance measurements. By completing the calibration process in advance at the factory, the system eliminates or reduces the need for subsequent in-vivo calibrations by patients, thereby improving productivity and convenience. The use of impedance-based methods during manufacturing provides sufficiently precise calibration data to maintain accurate measurements throughout the sensor's operational life
Solution Approach 2:
The impedance measurement process creates a digital copy or model of the sensor's electrical characteristics during manufacturing. This electrical fingerprint is stored and used to track and compensate for sensor behavior changes over time, enabling factory calibration to remain effective throughout the sensor's lifespan without requiring repeated high-precision calibration events
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 approach enhances sensor accuracy and reduces the reliance on blood glucose meter calibrations, improving performance and reducing manufacturing costs by identifying and removing damaged sensors, and enabling real-time sensitivity adjustments.
Implementation Method 1
determining an impedance of the analyte sensor based on the measured current flow
Data Source
AI summary
Various examples described herein are directed to systems and methods for determining an analyte concentration using an analyte sensor. A method may comprise disconnecting an analyte sensor from a measurement circuit and reconnecting the analyte sensor to the measurement circuit after an accumulation period. The method may comprise receiving a signal from the analyte sensor. The signal may be indicative of an amount of charge accumulated on the analyte sensor during the accumulation period. The method may also comprise determining an estimated analyte concentration level based on the received signal.