Biosensor Underfill Detection Using Variable Excitation Amplitude
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Solution Overview
Problem
Conventional biosensors face challenges in accurately and precisely detecting underfilled samples, leading to inaccurate analyte concentration measurements due to additional components increasing manufacturing costs and introducing variability, as well as delayed detection of underfill conditions.
Innovation Solution
A biosensor with an underfill detection system that applies a test excitation signal with varying amplitudes to determine if the sample is sufficient for analysis, comparing the output signals with underfill thresholds to generate an error signal when the sample is insufficient, prompting the user to add more fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional indicator electrodes are added to detect underfill conditions, then underfill detection capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The working electrode performs dual functions: it serves as the primary sensor for analyte detection and simultaneously acts as an indicator electrode for underfill detection by monitoring current flow during a preliminary voltage application phase before the actual measurement begins
Solution Approach 2:
The system uses its own working electrode and electrical circuitry to perform self-diagnosis for underfill detection, eliminating the need for separate indicator electrodes and their associated manufacturing complexity
2Reliability
If conventional underfill detection systems with separate indicator electrodes are used, then underfill detection is achieved, but manufacturing precision decreases due to introduced variability
Solution Approach 1:
The invention merges the working electrode and indicator electrode functions into a single electrode structure, eliminating the variability introduced by manufacturing separate indicator electrodes and their connections, thereby improving measurement accuracy while maintaining underfill detection capability
3Device complexity
If sample analysis proceeds without underfill detection, then device simplicity is maintained, but measurement accuracy deteriorates due to insufficient sample volume
Solution Approach 1:
The system performs a preliminary voltage application phase before the actual analyte measurement to detect underfill conditions, allowing early identification of insufficient sample volume and preventing inaccurate measurements while maintaining overall system simplicity
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 the accuracy and precision of biosensor readings by early detection of underfill conditions, reducing waste and improving measurement reliability.
Implementation Method 1
The analyte typically undergoes an oxidation/reduction or redox reaction when an excitation signal is applied to the sample
Implementation Method 2
An enzyme or similar species may be added to the sample to enhance the redox reaction
Data Source
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AI summary
A biosensor has an underfill detection system that determines whether a sample of a biological fluid is large enough for an analysis of one or more analytes. The underfill detection system applies an excitation signal to the sample, which generates an output signal in response to the excitation signal. The underfill detection system switches the amplitude of the excitation signal. The transition of the excitation signal to a different amplitude changes the output signal when the sample is not large enough for an accurate and/or precise analysis. The underfill detection system measures and compares the output signal with one or more underfill thresholds to determine whether an underfill condition exists.