Viable Particle Counter Autofluorescence Raman Interference
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Solution Overview
Problem
The detection of viable particles in dialysis fluid using autofluorescence methods is hindered by the interference of Raman-scattered light, making it difficult to accurately determine the presence or absence of viable particles due to wavelength overlap between autofluorescence and Raman-scattered light.
Innovation Solution
A viable particle counter that irradiates a dialysis fluid with a specific wavelength laser light, utilizing optical separators like long-pass or band-pass filters and dichroic mirrors to differentiate and reduce Raman-scattered light, allowing for the accurate detection and counting of autofluorescence from viable particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultraviolet light is radiated to detect autofluorescence from viable particles in dialysis fluid, then viable particle detection is enabled, but Raman-scattered light interferes with the measurement
Solution Approach 1:
The optical detection system is segmented into multiple detection channels: one for detecting autofluorescence signal and another for detecting Raman-scattered light signal. By separating the detection of these two signals, the system can distinguish viable particles from Raman scattering interference, thereby improving measurement precision while accounting for the harmful Raman scattered light.
Solution Approach 2:
The patent introduces an intermediary measurement approach by detecting Raman-scattered light as a separate signal that serves as a reference or indicator of interference. This intermediary signal allows the system to identify and compensate for Raman scattering effects, enabling accurate viable particle detection despite the presence of Raman-scattered light interference.
2Measurement precision
If the wavelength band of autofluorescence is selected using a filter, then specific autofluorescence detection is improved, but Raman-scattered light with the same wavelength still interferes
Solution Approach 1:
The detection system is divided into separate channels: one channel uses optical filters to select the autofluorescence wavelength band, while another channel detects the Raman-scattered light signal. This segmentation allows the system to maintain high specificity for autofluorescence detection while simultaneously monitoring and distinguishing Raman scattering interference, resolving the wavelength overlap problem.
Solution Approach 2:
The system employs feedback by using the detected Raman-scattered light signal as a reference to adjust or compensate for interference in the autofluorescence detection channel. By continuously monitoring the Raman signal and using it to correct or subtract interference from the autofluorescence measurement, the system maintains high detection specificity even when wavelength bands overlap.
3Measurement precision
If dual detection of scattered light and autofluorescence is performed, then viable particle identification is improved, but device complexity increases
Solution Approach 1:
The detection system is segmented into functionally independent modules: a scattered light detection module and an autofluorescence detection module. Each module is optimized for its specific detection task, which simplifies the design and operation of each individual module while achieving high overall identification accuracy through their combined use.
Solution Approach 2:
The patent implements a multi-functional detection system where a single integrated device performs both scattered light detection and autofluorescence detection. This universal approach allows one device to accomplish multiple detection functions, improving viable particle identification accuracy without proportionally increasing device complexity, as the system shares common components such as the light source and sample chamber.
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 high-accuracy counting of viable particles by isolating autofluorescence from Raman-scattered light, improving the precision of viable particle detection in real-time monitoring of dialysis fluids.
Implementation Method 1
a phenomenon that, when a light with a predetermined wavelength is first radiated to a given substance, an energy state that this substance has is excited (the substance absorbs the radiated light), and thereafter the substance emits extra energy to the outside as fluorescence at the time of returning to a ground state from the excited state
Implementation Method 2
a Raman-scattered light by the water is also detected in addition to the autofluorescence. This is because the radiated ultraviolet ray is scattered by the water (Raman scattering) when the ultraviolet ray is radiated to the water
Implementation Method 3
utilizing optical separators like long-pass or band-pass filters and dichroic mirrors to differentiate and reduce Raman-scattered light
Data Source
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AI summary
There is provided an art capable of detecting viable particles in a liquid and counting the number of the viable particles even if there is an influence of a Raman-scattered light by water. There are provided: a light emitting means (10) which radiates a light with a predetermined wavelength toward a liquid containing a detection target; an autofluorescence selecting optical means (70) which reduces transmission of a Raman-scattered light emitted from the liquid out of lights emitted due to an interaction of the target or the liquid with the light radiated from the light emitting means (10) and transmits an autofluorescence emitted from the target; and a viable particle determining means (2) which determines whether or not the target contained in the liquid is a viable particle, based on a light obtained after the Raman-scattered light is reduced by the autofluorescence selecting optical means (70), and the light emitting means (10) radiates the light with the predetermined wavelength that causes the autofluorescence and the Raman-scattered light to be different in peak wavelength.