Fluid Particle Detection Using Dual Polarization Fluorescence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting and characterizing fluid-borne particles using time-resolved laser-induced fluorescence are limited in their ability to provide detailed measurements, often resulting in false classification due to limited distinction between biological and non-biological particles based solely on fluorescence decay rates.
Innovation Solution
A measurement device and method utilizing a combination of fluid and light path geometries, ultrafast detectors, and acquisition electronics to acquire spectrally and timely resolved fluorescence responses from fluid-borne particles with laser pulses of different polarizations, separated by a short delay, allowing for improved characterization of individual particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time-resolved fluorescence measurement is used to distinguish biological and non-biological particles, then particle classification is achieved, but measurement precision is limited due to reliance on fluorescence decay rates alone
Solution Approach 1:
The patent transitions from single-dimensional fluorescence decay rate measurement to multi-dimensional characterization by incorporating polarization dimensions. Two linearly polarized laser pulses excite particles, and the emitted fluorescence is collected at multiple polarization angles (0°, 45°, 90°, 135°), creating additional measurement dimensions that reveal molecular orientation and chemical composition information beyond what decay rates alone can provide.
Solution Approach 2:
The patent changes the measurement parameters from solely temporal (fluorescence decay rate) to include spatial/polarization parameters. By measuring fluorescence intensity at different polarization angles and analyzing the anisotropy decay, the system extracts additional parameters (orientation angles, molecular alignment) that improve classification precision and reduce false counts.
2Measurement precision
If multiple measurement parameters are used to characterize particles, then identification accuracy improves, but device complexity increases
Solution Approach 1:
The patent segments the fluorescence measurement into multiple independent polarization channel measurements. Each channel (0°, 45°, 90°, 135°) is measured separately using beam splitters and polarizing beam splitters, allowing complex polarization state analysis to be broken down into simpler, independent measurement paths that can be processed individually.
Solution Approach 2:
The optical system uses universal components that serve multiple functions: beam splitters direct light to different detectors while also enabling polarization separation; photomultiplier tubes detect fluorescence intensity while the timing system captures decay kinetics; the same laser source provides both temporal and polarization measurement capabilities through its polarized output.
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 provides a reliable and cost-effective means for detailed detection and characterization of fluid-borne particles, reducing false classification rates by offering more detailed fluorescence response measurements and better identification of chemical composition.
Implementation Method 1
detecting and/or characterizing fluid-borne particles using laser-induced fluorescence of said particles
Implementation Method 2
a laser for emitting pulses of polarized laser light
Implementation Method 3
a first optical mirror located opposite the laser on the other side of the measurement volume for reflecting pulses of laser light emitted by the laser after they have crossed the measurement volume
Implementation Method 4
for rotating the polarization of the light of the pulses from the first direction of polarization to the second direction of polarization
Implementation Method 5
providing time-resolved information about fluorescent light at at least one wavelength emitted by particles
Implementation Method 6
an optical spectrometer for providing time-resolved information about fluorescent light at at least one wavelength
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Measurennent device for the detection and/or characterization of fluid-borne particles (9), the measurement device comprising means (1, 10) for producing a flow of fluid along a fluid flow path, a laser (2) positioned for emitting pulses of laser light polarized in a first direction of polarization, in a measurement volume of the fluid flow path, each pulse having a pulse duration, means (3) for directing pulses of laser light polarized in a second direction of polarization in the measurement volume, wherein the second direction of polarization is different from the first direction of polarization, a first optical spectrometer for capturing fluorescent light emitted by individual fluid-borne particles (9) in the measurement volume and measuring intensity of the captured fluorescent light at at least one determined wavelength at a sampling rate of at least three samples per pulse duration, wherein the means (3) for directing are configured such that they direct a pulse of laser light polarized in the second direction of polarization in the measurement volume each time a pulse of laser light emitted by the laser (2) and polarized in the first direction has crossed the measurement volume, the time delay between the moment of crossing the measurement volume by the pulse emitted by the laser and the moment of crossing the measurement volume by the pulse directed by the means (3) for directing is longer than the pulse duration and shorter than a travel time of the fluid in the measurement volume. Measurement method for the detection and/or characterization of fluid-borne particles (9) using the measurement device of the invention.