Fluorescence Sensor Ultrasonic Standing Wave Microalgae Measurement
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Solution Overview
Problem
Existing fluorescence sensors for measuring microalgae face challenges with low measurement accuracy and high lower limits due to fluorescence intensity being affected by pigments both in the algae and dissolved in water, especially when algal density is low, leading to increased noise and reduced signal clarity.
Innovation Solution
A fluorescence sensor system that includes an ultrasonic control unit to form nodes and antinodes of ultrasonic standing waves in the measurement region, allowing for controlled algal density adjustment and signal processing to isolate the fluorescence signal from noise, thereby enhancing measurement accuracy and lowering the detection limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fluorescence measurement is performed in a conventional manner without ultrasonic wave control, then the measurement process is simple, but measurement accuracy is low and measurement lower limit is high due to noise from dissolved pigments
Solution Approach 1:
The patent applies ultrasonic vibration to create standing waves in the measurement region. The ultrasonic wave generator produces mechanical vibrations that form nodes and antinodes, causing microalgae to concentrate at nodes while dissolved pigments remain distributed. This physical separation enables the fluorescence signal to originate predominantly from microalgae, significantly improving measurement accuracy while maintaining a relatively simple system configuration.
Solution Approach 2:
The measurement process is segmented into distinct phases: ultrasonic wave generation, node/antinode formation, fluorescence measurement at nodes, and signal processing. By segmenting the measurement process and performing measurements specifically at node regions where microalgae concentrate, the system achieves high measurement accuracy. The signal processing unit further segments the total fluorescence signal into microalgae-specific signal and dissolved pigment noise through mathematical operations.
2Measurement precision
If algal density in measurement region is low, then the measurement region represents natural conditions better, but measurement noise from dissolved pigments exceeds measurement signal from algae pigments
Solution Approach 1:
Ultrasonic standing waves create regions of high concentration (nodes) and low concentration (antinodes) of microalgae. Even when the overall algal density in the measurement region is low, the nodes provide localized areas where microalgae are sufficiently concentrated to generate a strong fluorescence signal that exceeds the noise from dissolved pigments, improving the signal-to-noise ratio.
Solution Approach 2:
The ultrasonic wave generator performs preliminary action by pre-concentrating microalgae at node positions before fluorescence measurement. This preliminary concentration ensures that when measurement occurs, the microalgae are already positioned to maximize signal strength, allowing accurate measurement even when overall algal density is low.
3Measurement precision
If ultrasonic standing wave is formed to concentrate microalgae at nodes, then fluorescence signal from microalgae is enhanced, but dissolved pigments are excluded from measurement
Solution Approach 1:
The ultrasonic standing wave creates a stable pattern of nodes and antinodes that continuously concentrates microalgae at nodes. This mechanical vibration method provides continuous enhancement of the fluorescence signal from microalgae while simultaneously excluding dissolved pigments from the measurement region, achieving both signal enhancement and noise reduction simultaneously.
Solution Approach 2:
The ultrasonic standing wave acts as an intermediary that mediates between the microalgae and the measurement system. It facilitates the separation of microalgae from dissolved pigments by creating physical concentration zones, allowing the measurement system to selectively measure microalgae fluorescence while excluding dissolved pigment interference.
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
The system achieves high measurement accuracy and a lower detection limit by isolating the fluorescence signal from noise, effectively improving the measurement of microalgae density even at low concentrations.
Implementation Method 1
an algae control unit configured to form a node and an antinode of an ultrasonic standing wave in the measurement region to control an algal density
Implementation Method 2
a fluorescence measurement unit including a light emitter configured to irradiate excitation light onto a measurement region and a detector configured to measure fluorescence emitted from the measurement region
Implementation Method 3
measuring total fluorescence intensity emitted by irradiating excitation light in a state in which there is no ultrasonic wave in a measurement region, measuring noise fluorescence intensity by forming a node of an ultrasonic standing wave in the measurement region, and calculating an algal density using signal fluorescence intensity which is a result of subtracting the noise fluorescence intensity from the total fluorescence intensity
Data Source
AI summary
The present invention relates to a fluorescence sensor for measuring microalgae and a method of operating the same. The fluorescence sensor for measuring the microalgae includes a fluorescence measurement unit including a light emitter configured to irradiate excitation light onto a measurement region and a detector configured to measure fluorescence emitted from the measurement region, an algae control unit configured to form a node and an antinode of an ultrasonic standing wave in the measurement region to control an algal density, and a signal processing unit configured to calculate the algal density using fluorescence intensity signals according to an operation mode of the algae control unit.