# US 10,481,064 B2 · Ballast water monitoring device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,064 B2 - Document ID: US10481064B2 - Status: Granted - Kind: B2 - Application number: 15/755,782 - Filed: 2016-08-10 - Published: 2019-01-31 - Granted: 2019-11-19 - Earliest claimed: 2015-08-28 - Assignees: Chelsea Technologies Group Ltd - Applicants: Chelsea Technologies Group Ltd - Inventors: Kevin Oxborough; John Attridge; David Andrewes - Web page: https://patentgrep.com/patent/US10481064B2 ## CPC - G01N 15/06: Investigating concentration of particle suspensions (by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10) - B63J 4/002: {for treating ballast water} - C02F 1/00: Treatment of water, waste water, or sewage (C02F3/00 - C02F9/00 take precedence) - C02F 1/008: {Control or steering systems not provided for elsewhere in subclass C02F} - G01N 1/38: Diluting, dispersing or mixing samples - G01N 21/6408: {with measurement of decay time, time resolved fluorescence} - G01N 21/6486: {Measuring fluorescence of biological material, e.g. DNA, RNA, cells (G01N21/6428 takes precedence)} - G01N 33/1826: {Organic contamination in water} - C02F 2103/008: {Originating from marine vessels, ships and boats, e.g. bilge water or ballast water} - C02F 2209/001: Upstream control, i.e. monitoring for predictive control - C02F 2209/36: Biological material, e.g. enzymes or ATP - C02F 2303/04: Disinfection - G01N 15/075: by optical means - G01N 2001/2064: {using a by-pass loop} - G01N 2001/386: {Other diluting or mixing processes} - G01N 2021/635: {Photosynthetic material analysis, e.g. chrorophyll} - G01N 2021/6419: {Excitation at two or more wavelengths} - G01N 2021/6478: {Special lenses} - G01N 2021/6482: {Sample cells, cuvettes} - G01N 2201/0627: Use of several LED's for spectral resolution - G01N 2201/0631: Homogeneising elements - G01N 2201/0638: Refractive parts - G01N 2201/064: Stray light conditioning - G01N 2201/0696: Pulsed - Y02A 20/20: Controlling water pollution; Waste water treatment - Y02W 10/37: using solar energy - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B63J: AUXILIARIES ON VESSELS - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract A ballast water monitoring device and a method for detecting live phytoplankton are disclosed. The device comprises a chamber for receiving a sample, at least one light source to emit light towards the sample, a light detector to receive light from the sample and generate a light signal, and a controller. The controller is configured to control the at least one light source to emit a single pulse of light, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and perform an action if the calculated variable fluorescence is greater than the predetermined reference limit. ## Claims ### Claim 1 A ballast water monitoring device for detecting live phytoplankton, the device comprising: a chamber for receiving a sample; at least one light source to emit light towards the sample; a light detector to receive light from the sample and generate a light signal; and a controller configured to: control the at least one light source to emit a single pulse of light with a duration of up to 450 μs, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and perform an action when the calculated variable fluorescence is greater than the predetermined reference limit. ### Claim 2 (depends on 1) The ballast water monitoring device of claim 1, comprising a plurality of light sources, wherein each light source is associated with a different wavelength. ### Claim 3 (depends on 1) The ballast water monitoring device of claim 1, further comprising an indicator, for indicating to the user that the variable fluorescence exceeds the predetermined reference limit, wherein performing an action comprises activating the indicator. ### Claim 4 (depends on 1) The ballast water monitoring device according to claim 1, wherein the pulse of light has a duration of greater than 100 μs, or greater than 200 μs, or greater than 300 μs, or between 350 μs and 450 μs, or between 390 μs and 410 μs. ### Claim 5 (depends on 1) The ballast water monitoring device according to claim 1, wherein the pulse of light has a duration of about 400 μs. ### Claim 6 (depends on 1) The ballast water monitoring device according to claim 1, wherein the controller is configured to measure the variable fluorescence by measuring the intensity of the received light at intervals of between 0.1 μs and 10 μs, or between 0.2 and 8 μs, or between 0.5 and 5 μs, or between 0.8 and 3 μs. ### Claim 7 (depends on 1) The ballast water monitoring device according to claim 1, wherein the controller is configured to measure the variable fluorescence by measuring the intensity of the received light at about 1 μs intervals. ### Claim 8 (depends on 1) The ballast water monitoring device according to claim 1, wherein the at least one light source is configured to emit light having a wavelength of one of about 450 nm, 470 nm, 530 nm and 624 nm, wherein when there are a plurality of light sources, the plurality of light sources are configured to emit light having wavelengths of at least two of about 450 nm, 470 nm, 530 nm and 624 nm simultaneously. ### Claim 9 (depends on 1) The ballast water monitoring device according to claim 1, wherein the chamber comprises an inlet and an outlet, through which water can continuously flow, wherein the chamber comprises a removable blocking member for blocking the inlet or the outlet to allow a discrete sample to be measured, wherein at least one valve arranged in the inlet or the outlet to block the inlet or the outlet to allow a discrete sample to be measured and wherein the blocking member comprises a stirrer for stirring the sample. ### Claim 10 (depends on 1) The ballast water monitoring device according to claim 1, further comprising a plurality of lenses configured to generate a uniform light field directed into the chamber, wherein at least one of the plurality of lenses is an achromatic doublet lens, wherein the plurality of lenses comprise an array of plano-convex lenses positioned directly in front of the plurality of light sources and wherein when the plurality of lenses comprise an array of plano-convex lenses positioned directly in front of the plurality of light sources, the plurality of lenses comprise a shortpass filter placed in front of the array of plano-convex lenses. ### Claim 11 (depends on 1) The ballast water monitoring device according to claim 1, wherein the controller is configured to estimate a minimal fluorescence [F0] of the sample using regression analysis, and subtract that value from the maximal fluorescence [Fm] to provide Fv, wherein the controller is configured to estimate F0 of the sample using regression analysis of a first part of the generated light signal, estimate Fm of the sample using regression analysis of a second part of the generated light signal, and subtract F0 from Fm to provide Fv. ### Claim 12 (depends on 1) The ballast water monitoring device according to claim 1, wherein the controller is further configured to repeat the steps of: controlling the at least one light source to emit a single pulse of light; and calculating the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, and the controller being further configured to: average the calculated variable fluorescence over the number of repetitions; and perform the action when the average calculated variable fluorescence is greater than the predetermined reference limit. ### Claim 13 (depends on 1) The ballast water monitoring device according to claim 1, wherein the ballast water monitoring device further comprises a stirrer for stirring the sample, wherein the stirrer is arranged to pass through a side wall of the chamber. ### Claim 14 A system comprising: a ballast water treatment system; and a ballast water monitoring device comprising: a chamber for receiving a sample; at least one light source to emit light towards the sample; a light detector to receive light from the sample and generate a light signal; and a controller configured to: control the at least one light source to emit a single pulse of light with a duration of up to 450 μs, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and when the calculated variable fluorescence is greater than the predetermined reference limit the ballast water monitoring device controls the ballast water treatment system to eliminate live phytoplankton cells. ### Claim 15 A method of determining whether live phytoplankton are present in a sample, the method comprising: generating a pulse of light with a duration of up to 450 μs and directing it towards the sample; receiving a light from the sample in response to receiving the pulse of light, and generating a light signal; calculating the variable fluorescence [Fv] of the sample in response to receiving the pulse of light at time intervals less than the duration of the pulse of light; comparing the calculated variable fluorescence to a predetermined reference limit; and performing an action when the calculated variable fluorescence exceeds the predetermined reference limit. ### Claim 16 (depends on 15) The method of claim 15, wherein generating the pulse of light comprises activating a plurality of light sources, wherein performing the action comprises indicating that the variable fluorescence exceeds the predetermined reference limit and wherein the performing the action comprises controlling a means for exterminating live phytoplankton cells. ### Claim 17 (depends on 15) The method according to claim 15, wherein the pulse of light has a duration of greater than 200 μs, or greater than 300 μs, or between 350 μs and 450 μs, or between 390 μs and 410 μs, or about 400 μs; and the method comprising calculating the variable fluorescence by measuring the intensity of the generated light signal at intervals of between 0.1 μs and 10 μs, or between 0.2 and 8 μs, or between 0.5 and 5 μs, or between 0.8 and 3 μs. ### Claim 18 (depends on 15) The method of according to claim 15, wherein the pulse of light comprises light having a wavelength of one of about 450 nm, 470 nm, 530 nm and 624 nm, wherein when a plurality of light sources are activated, the pulse of light comprises light having wavelengths of at least two of about 450 nm, 470 nm, 530 nm and 624 nm. ### Claim 19 (depends on 15) The method according to claim 15, comprising generating a uniform light field and directing it into a chamber in which the sample is contained. ### Claim 20 (depends on 15) The method according to claim 15, comprising estimating a minimal fluorescence [F0] of the sample using regression analysis, and subtracting that value from the maximal fluorescence [Fm] to provide Fv, wherein estimating F0 of the sample using regression analysis of a first part of the generated light signal, estimating Fm of the sample using regression analysis of a second part of the generated light signal, and subtracting F0 from Fm to provide Fv.