Microbial Particle Concentration Measurement via Fluorescence Attenuation Slope
Solution Overview
Problem
Existing methods for measuring microbial particle concentration in fluids are inaccurate due to the influence of non-microbial particles, as they cannot distinguish between microbial and non-microbial particles based on fluorescence attenuation rates.
Innovation Solution
A microbial particle measuring apparatus that irradiates a fluid with light of a predetermined wavelength, selectively receives fluorescence, and calculates the concentration of microbial particles by analyzing the attenuation rate of fluorescence intensity in specific time periods where the slope of the signal waveform is smaller than a predetermined value, using substances like tryptophan and tyrosine as indices to minimize interference from other particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fluorescence intensity difference is measured between immediately after irradiation and after predetermined time, then microbial particle concentration can be calculated, but measurement accuracy deteriorates due to interference from non-microbial particles
Solution Approach 1:
The patent segments the fluorescence attenuation process into two distinct time periods: a first period with rapid attenuation (slope smaller than predetermined value) corresponding to microbial particles, and a second period with slower attenuation corresponding to non-microbial particles. By analyzing only the first period, the method isolates microbial particle signals from background interference.
Solution Approach 2:
The patent performs preliminary identification of the time period characteristic of microbial particles by detecting when the fluorescence attenuation slope becomes smaller than a predetermined value. This preliminary action establishes the measurement window before non-microbial particle interference becomes significant, enabling accurate microbial particle concentration calculation.
2Measurement precision
If continuous light irradiation is applied for predetermined time, then fluorescence fading of microbial particles can be detected, but measurement precision deteriorates due to simultaneous fluorescence emission from non-microbial particles
Solution Approach 1:
The patent dynamically adjusts the measurement approach by continuously monitoring the attenuation slope and identifying transition points between different attenuation phases. Instead of using a fixed time window, the system adapts the measurement period based on the actual fluorescence decay characteristics observed in real-time, optimizing the signal-to-noise ratio.
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 allows for accurate determination of microbial particle concentration by isolating the attenuation due to microbial particles, reducing interference from non-microbial particles and enhancing measurement precision.
Implementation Method 1
a light emitter configured to irradiate a fluid with light of a predetermined wavelength
Implementation Method 2
a fluorescence receiver configured to selectively receive fluorescence emitted from particles contained in the fluid and output a signal having a magnitude corresponding to intensity of the fluorescence
Data Source
AI summary
A microbial particle measuring apparatus includes: a light emitter configured to irradiate a fluid with light of a predetermined wavelength over a predetermined measurement time; a fluorescence receiver configured to selectively receive fluorescence emitted from particles contained in the fluid and output a signal having a magnitude corresponding to intensity of the fluorescence; a signal acquisition unit configured to obtain the signal output from the fluorescence receiver at regular intervals over the measurement time; and a determiner configured to calculate a slope of waveform of the signal obtained by the signal acquisition unit, and determine a concentration of microbial particles contained in the fluid using an attenuation amount of fluorescence intensity generated in a time period in which the slope in the measurement time is smaller than a predetermined value as an amount of attenuation derived from the microbial particles.