Time Domain Impedance Detection for Rapid Pathogen Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting viable microorganisms in liquid media are labor-intensive, time-consuming, and costly, requiring manual handling and complex instrumentation to measure impedance over a wide range of frequencies, which limits their speed and efficiency in identifying pathogens.
Innovation Solution
A method involving the application of electrical pulses across electrodes in a liquid-containing sample to generate initial electrical response signals within short time windows, allowing for rapid detection of microorganism proliferation by analyzing changes in electrical properties before steady-state conditions are reached, using a time domain impedance detection system with DC pulses and curve-fitting equations to determine the presence of pathogens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency domain impedance sensing methods are used to detect viable microorganisms, then measurement precision is improved, but device complexity and loss of time increase due to requiring complex instrumentation and manual handling over wide frequency ranges
Solution Approach 1:
The patent changes the measurement parameter from frequency domain (multiple frequencies) to time domain (single pulse duration measurement). By measuring the duration of the electrical response signal after applying a single DC pulse, the system achieves accurate pathogen detection without requiring complex multi-frequency instrumentation, thus reducing device complexity while maintaining detection precision
Solution Approach 2:
The patent extracts only the essential measurement information (response signal duration) from the complex frequency domain analysis. By focusing on a single time-domain parameter rather than analyzing impedance across wide frequency ranges, the system simplifies the measurement process and reduces instrumentation requirements while preserving detection accuracy
2Measurement precision
If traditional culture methods are used to identify pathogens, then measurement precision is improved, but loss of time increases due to requiring 12-72 hours or longer for culture results
Solution Approach 1:
The patent replaces the biological culture system (which requires days for microorganism proliferation) with an electrical detection system. By measuring changes in electrical response signal duration caused by pathogen presence in the liquid media, the system achieves rapid pathogen identification within minutes while maintaining accuracy, eliminating the time-consuming culture step
3Measurement precision
If manual handling and complex instrumentation are used for impedance measurement, then measurement precision is improved, but productivity decreases due to labor-intensive procedures
Solution Approach 1:
The patent employs automated electronic systems that perform measurements and analysis without manual intervention. The system automatically applies DC pulses, detects response signals, measures duration parameters, and identifies pathogens present in liquid media, enabling high-throughput sample analysis while maintaining measurement precision and eliminating labor-intensive procedures
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 enables faster, simpler, and less expensive detection of viable microorganisms, reducing the time required for pathogen identification and improving the efficiency of sample analysis compared to traditional frequency domain impedance sensing methods.
Implementation Method 1
In the presence of an AC electric field, a viable (intact) bacterial cell membrane becomes polarized, leading to the buildup of charges across the membrane such that viable microbial cells behave like electrical capacitors.
Implementation Method 2
Application of alternating current (AC) electrical signals to liquid suspensions provides a basis for detecting the presence of microorganisms
Data Source
Figure 1A~1C
Figure 2
Figure 3A
AI summary
A system and method for rapid detection of viable microorganisms (e.g., pathogens) in liquid media suspensions utilizes at least two electrodes in electrical communication with a suspension (e.g., liquid media possibly containing microorganisms). Electrical response to an electrical pulse in a short initial time window (e.g., no longer than a time required to attain 95% (or another threshold percentage) of a steady state electrical response value after a change in state of the pulse) permits bulk electrical response of the suspension between the electrodes to be determined before electrical response signals are dominated by double layer formation at surfaces of the electrodes. Pulse application and detection of electrical response to a change in state of a pulse may be repeated over time, with changes in such response being useful to detect microorganism proliferation in a bulk suspension.