Apparatus for counting viable particles in liquid in real time, dialysis fluid monitoring system and purified water monitoring system using the apparatus, and method of counting viable particles in liquid in real time
Inventors
ICHIJYO, Kazuo • SEKIMOTO, Kazuma • SEKIGAWA, Kousei • KIMOTO, YUKIHIRO • Kosaka, Takayuki
Assignees
Publication Number
US-9267845-B2
Publication Date
2016-02-23
Expiration Date
2032-11-28
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Abstract
A viable particle counting apparatus 77 includes devices 10, 70, 2. The device 10 radiates a light with a predetermined wavelength toward a liquid containing a detection target. The device 70 reduces a Raman-scattered light emitted from the liquid out of lights emitted due to an interaction of the light radiated by the device 10 with the target or the liquid and selects an autofluorescence light emitted from the target. The device 2 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 device 70. The device 10 radiates the light with a wavelength that causes the autofluorescence light and the Raman-scattered light to be different in peak wavelength.
Core Innovation
The invention relates to a viable particle counting apparatus configured to detect viable particles existing in a liquid in real time. The apparatus includes a light emitting element that radiates light with a predetermined wavelength toward a liquid containing a detection target. The apparatus further includes an optical filter which reduces transmission of Raman-scattered light emitted from the liquid but transmits autofluorescence light emitted from the target, and a determining device to decide whether the target contained in the liquid is a viable particle based on the light obtained after reduction of Raman-scattered light.
The core innovation addresses the problem posed by the difficulty in distinguishing autofluorescence light from Raman-scattered light when ultraviolet light is radiated to water containing viable particles. Raman-scattered light overlaps with autofluorescence light in wavelength, making it challenging to detect only viable particles using autofluorescence as an index. Additionally, conventional methods for detecting viable particles in dialysis fluids or purified water require lengthy cultivation, chemical treatments, or indirect measures that cannot provide real-time results during processes such as blood dialysis or water purification.
The invention solves this by selecting the wavelength of the radiated light so that the peak wavelengths of the autofluorescence light and Raman-scattered light differ. This enables use of optical filters such as long-pass or band-pass filters to selectively reduce Raman-scattered light transmission while transmitting autofluorescence light. Consequently, based on the transmitted autofluorescence light, it is possible in real time to accurately determine the presence and count viable particles in liquids such as dialysis fluid or purified water, improving upon the problems of conventional methods.
Claims Coverage
The patent includes 15 claims with 2 independent apparatus claims, an independent system claim for dialysis fluid monitoring, an independent system claim for purified water monitoring, and an independent method claim. The main inventive features focus on aspects of the viable particle counting apparatus, light management to distinguish autofluorescence from Raman scattering, and systems incorporating the apparatus.
Wavelength selection for autofluorescence and Raman scattered light separation
A viable particle counting apparatus comprising a light emitting element radiating light toward a liquid where the light wavelength causes the peak wavelengths of autofluorescence light and Raman scattered light to differ, enabling clear separation.
Optical filtering to reduce Raman-scattered light while transmitting autofluorescence light
Use of an optical filter that reduces transmission of Raman-scattered light emitted from the liquid but transmits autofluorescence light emitted by viable particles, facilitating accurate detection.
Use of dichroic mirror and dual light receiving arrangement with threshold determination
Incorporation of a dichroic mirror reflecting scattered light and transmitting autofluorescence and Raman-scattered light, with first and second light receiving devices outputting signals compared against thresholds to determine viable particle presence based on simultaneous signal detection, alongside a light shielding device preventing extraneous light intrusion.
Predetermined light wavelength and filter cutoff selection
Radiating light with wavelength between 375 nm and 420 nm and employing an optical filter with cutoff wavelength between 450 nm and 490 nm to optimize separation of autofluorescence from Raman scattering.
Use in dialysis fluid monitoring system with fluid distribution and branching
An apparatus integrated with a distributing device distributing dialysis fluid and a dividing device branching off part of the fluid for detection, using autofluorescence light to determine presence of viable particles in dialysis fluid before human administration.
Use in purified water monitoring with branching and real-time determination
An apparatus integrated with a dividing device branching off water undergoing or having undergone purification, radiating light of predetermined wavelength, reducing Raman-scattered light, and determining viable particles based on autofluorescence light emitted due to light interaction with the target.
Optimized wavelength and filter cutoff for purified water monitoring
Radiating light with wavelength between 375 nm and 450 nm and employing an optical filter with cutoff wavelength between 450 nm and 600 nm for purified water applications to improve viable particle detection accuracy.
Dialysis fluid monitoring system incorporating viable particle counting apparatus
A system for supplying dialysis fluid to multiple subjects including monitoring apparatuses and a viable particle counting apparatus as part of either the supply or monitoring apparatuses, incorporating distributing and dividing devices, light emission, optical filtering, and determination devices to detect viable particles in dialysis fluids, coupled with a notifying device.
Multiple apparatuses installed in dialysis monitoring apparatuses
Provision of viable particle counting apparatus in each dialysis monitoring apparatus within the dialysis fluid monitoring system for per-subject monitoring.
Purified water monitoring system with purification stages and distribution reservoirs
A system with a purifying device implementing multiple purification treatments, water delivery device, and at least one viable particle counting apparatus installed between purification stage basins and distribution reservoirs, including dividing device, light emitting element, optical filtering, and determination device to detect viable particles, alongside notification capability.
Integration with chemical injection and system control for purification
The purified water monitoring system further includes chemical supplying, injecting, amount control devices, and a system controlling apparatus that instructs chemical injection amount adjustment based on determination results from the viable particle counting apparatus.
Viable particle counting method with wavelength selection and optical filtering
A method including radiating light with predetermined wavelength separating autofluorescence peak from Raman scattered peak, reducing Raman scattered light transmission and transmitting autofluorescence light, and determining viable particle presence based on the filtered light.
Reflecting and transmitting scattered and autofluorescence light steps for determination
Method including reflecting scattered light and transmitting light containing autofluorescence and Raman scattered light, with determination based on transmitted light after filtering.
Simultaneous dual signal receiving with threshold comparison and light shielding for accurate determination
Receiving first and second signals from transmitted and reflected lights, outputting detection signals when second signal exceeds threshold, preventing extraneous light with shielding, and determining viable particle presence when both signals received simultaneously and surpass thresholds.
Specified wavelength and filter cutoff ranges for method steps
Using radiation light wavelength between 375 nm and 420 nm and optical filter cutoff wavelength between 450 nm and 490 nm during the method.
The claims collectively cover an apparatus and methods for counting viable particles in liquids by selecting radiation wavelengths that distinguish autofluorescence from Raman scattering, using optical filters and dichroic mirrors for light separation, processing dual light signals with threshold-based determination, and incorporating these in dialysis fluid and purified water monitoring systems with notification capabilities.
Stated Advantages
Improved counting accuracy of viable particles by reducing interference from Raman-scattered light while efficiently detecting autofluorescence light emitted by viable particles.
Capability to detect and count viable particles in liquids in real time, enabling rapid determination of contamination.
Enables real-time monitoring during processes such as blood dialysis and water purification, allowing for immediate measures to reduce patient or human body exposure to viable particles.
Reduces the need for lengthy cultivation or chemical treatment methods that delay detection results.
Allows size measurement of viable particles by using intensities of scattered and autofluorescence light signals.
Enables integration into dialysis fluid and purified water systems for automated monitoring and control, including chlorine injection adjustment based on viable particle presence.
Documented Applications
Counting viable particles in dialysis fluid administered to the human body during blood dialysis or blood filtration.
Dialysis fluid monitoring system for multiple patients incorporating viable particle counting to detect contamination in real time.
Monitoring purified water in water purification plants, including during stages of water purification and in distribution reservoirs.
Purified water monitoring system with multiple viable particle counting apparatuses to enable real-time adjustment of sterilizing chemical (chlorine) injection.
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