US3864551A - Coincidence correction circuit - Google Patents
Coincidence correction circuit Download PDFInfo
- Publication number
- US3864551A US3864551A US447530A US44753074A US3864551A US 3864551 A US3864551 A US 3864551A US 447530 A US447530 A US 447530A US 44753074 A US44753074 A US 44753074A US 3864551 A US3864551 A US 3864551A
- Authority
- US
- United States
- Prior art keywords
- pulses
- gate
- memory
- operative
- correction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000012937 correction Methods 0.000 title claims abstract description 48
- 239000002245 particle Substances 0.000 claims abstract description 74
- 230000004044 response Effects 0.000 claims description 23
- 239000007788 liquid Substances 0.000 claims description 17
- 238000010790 dilution Methods 0.000 claims description 7
- 239000012895 dilution Substances 0.000 claims description 7
- 230000001960 triggered effect Effects 0.000 claims description 6
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 210000004027 cell Anatomy 0.000 description 14
- 230000000875 corresponding effect Effects 0.000 description 7
- 239000012530 fluid Substances 0.000 description 3
- 210000000601 blood cell Anatomy 0.000 description 2
- 238000004820 blood count Methods 0.000 description 2
- 239000013256 coordination polymer Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 210000003743 erythrocyte Anatomy 0.000 description 2
- 210000000265 leukocyte Anatomy 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 230000003190 augmentative effect Effects 0.000 description 1
- 210000001772 blood platelet Anatomy 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K21/00—Details of pulse counters or frequency dividers
- H03K21/02—Input circuits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/10—Investigating individual particles
- G01N15/1031—Investigating individual particles by measuring electrical or magnetic effects
- G01N15/12—Investigating individual particles by measuring electrical or magnetic effects by observing changes in resistance or impedance across apertures when traversed by individual particles, e.g. by using the Coulter principle
- G01N15/131—Details
- G01N15/132—Circuits
Definitions
- a coincidence correction circuit provide correction which is substantially in conformity with the actual error which arises in a particle counting system and which provides effectively continuous correction for such error to produce a corrected count throughout the entire counting range.
- a correction pulse is added to the accumulating measured particle count to correct the count in accordance with the statistically determined actual nature of the accumulating error.
- FIG. 1 is a schematic representation of a particle counting system in which the invention is useful
- FIG. 2 is a block diagram representation of a coincidence correction circuit according to the invention.
- FIG. 3 is a block diagram representation of a typical implementation of the circuitry of FIG. 2.
- FIG. 1 A particle counting system in which the invention is useful is shown diagrammatically in FIG. 1 and which itself is the subject of US. Pat. No. 27,902.
- This system includes a conductivity cell or transducer I0 having a metering aperture and electrodes therein for providing electrical pulses on output line 12 corresponding and in response to particles passing through the aperture thereof.
- Particle-containing liquid is drawn from a sample container into cell 10 via an input tube 14 and exits through a-tube 16 which terminates in a waste vessel 18 to which is also coupled to pump 20.
- Pump 20 provides a negative pressure for drawing sample liquid through cell 10 for analysis during a counting run.
- the output pulses from cell 10 are applied to an amplifier 22, the output of which is coupled to logic circuitry 24 which processes the received pulses to provide an output signal to a count display 26 which visually indicates the particle count for a given quantity of sample liquid.
- the sample quantity being analyzed is determined by volume metering means 28 which senses a known quantity of sample liquid flowing through tube 16 and provides electrical start and stop signals to logic circuitry 24 to define a counting interval within which a particle count is accumulated for display.
- Appropriate controls 30 are coupled to logic circuitry 24 for operation thereof.
- the passage of a particle through the metering aperture of conductivity cell 10 alters the impedance of the fluid path within the cell, causing the provision of a cor responding'electrical pulse which is then processed for accumulating a particle count.
- two or more particles can simultaneously pass through the metering aperture, giving rise to the production of a single pulse which erroneously denotes the passage of a single particle.
- the error occasioned by such multiple particle passages is termed coincidence error and produces a lower than true count.
- the coincidence error is statistically predictable for known aperture sizes and concentrations of sample liquid and the correction is required at predetermined counts of a sequence of measured counts.
- the present invention provides the circuitry for augmenting the measured count throughout a counting run by addition of correction pulses necessary to provide a corrected output count actually representative of the true count.
- the novel circuitry is shown in FIG. 2 and includes first and second multivibrators 32 and 34, each of which receive the electrical pulses representative of measured particle count.
- Multivibrator 32 provides output pulses as a clock signal to an address register 36 and also provides its output pulses as one input of OR gate 38, the output of which gate is the corrected count.
- the output pulses from multivibrator 34 are applied as one input to NAND gates 40 and 42, the outputs of which are applied to respective inputs of OR gate 38.
- Address register 36 has its output lines coupled to the inputs of a read-only memory 44, the output of which is coupled to a multiplexer 46 which provides first and second output signals to gates 40 and 42 respectively.
- a control signal is applied from a suitable source to an input of gate 40 and via an inverter 48 to an input of gate .42.
- the multivibrators 32 and 34 typically are one shot multivibrators, multivibrator 32 being triggered on the trailing edge of an input pulse while multivibrator 34 is triggered on leading edge of the input pulse. As a result, a predetermined time delay is provided between the respective output pulses from the multivibrators sufficient to permit signal processing for providing correction data.
- the address register 36 provides an output code corresponding to the number of clock pulses applied thereto and which code addresses a read-only memory 44 which has stored therein data representative of the coincidence points of a correction chart at which additional pulses are to be added to a measured count.
- memory 44 provides an output code to multiplexer 46 which produces an output signal to gate 40 or 42 to cause an additional pulse to be added to the measured count for correction.
- the read-only memory 44 can have stored therein correction data for different needed corrections. For example, memory 44 can store correction data for multiple sets of data. Only one NAND gate 40 or 42 is operative in accordance with the value of the control signal applied thereto depending upon the type of particles, say red cells or white cells, being counted.
- pulses provided by a particle counting system transducer and of a number representative of measured particle count are applied to multivibrator 32 which provides corresponding output pulses to OR gate 38 which, in turn, provides output pulses for subsequent processing and display.
- the input pulses are also applied to multivibrator 34 which provides corresponding pulses to an input of NAND gates 40- and 42.
- a control signal is applied to one or the other of gates 40 and 42 to enable a selected one of these gates in accordance with the type of blood cells being counted. For example, during a red blood cell counting run an enabling signal can be applied to gate 40 while gate 42 is enabled during a white blood cell counting run.
- control signal is a logic level applied to gate 40 and the inverse of which is applied to gate 42.
- a control input of logic level one will provide a one level'to gate 40 and a zero level to gate 42.
- a control level of zero will pro-' vide a zero level at gate 40 and a one level at gate 42.
- Address register 36 is operative in response to the clock pulses provided by multivibrator 32, and which in turn is representative of the input pulses to provide a parallel output code to sequentially address memory 44 in accordance with successive values of the received particle count.
- the memory provides an output code to multiplexer 46 which in turn provides an output signal to gates 40 and 42.
- the enabled one of gates 40 or 42 upon receipt of a signal from multiplexer 46 and multivibrator 34, provides an output pulse to OR gate 38 which provides a correction pulse for addition to the then count.
- Read-only memory 44 is typically a semiconductor memory programmed in accordance with the corrections needed for a particular aperture size and sample liquid dilution and which in the illustrated embodiment -has stored data for both red cell and white cell coincidence correction.
- the multiplexer 46 will decode the memory output codes provided for both red cell and white cell coincidence correction, but, as described above, only the intended correction information is employed as determined by the enablement of gate 40 or 42 depending upon whether red or white cells are being counted.
- novel circuitry is typically implemented in integrated circuit form and with the read-only memory programmed in accordance with the configuration of a particular metering aperture employed in the transducer ofa particle counting system and the dilution ratios of the sample liquid.
- FIG. 3 A preferred implementation of the novel circuit is shown in FIG. 3 wherein the address register 36 is comprised of three integrated circuit binary counters 50, 52 and 54, such as Texas Instrument type 7493 counters.
- the clock signal from multivibrator 32 is applied to the clock input of counter 50 and the D output is coupled to the clock input of counter 52 while the D output thereof is, in turn, coupled to the input of counter 54.
- the A and B outputs of counter 50 are coupled to the respective control inputs of multiplexing gates 56 and 58 which gates comprise the multiplexer 46 of FIG. 2.
- Gates 56 and 58 are typically Texas Instruments type 74153 multiplexers.
- the C and D outputs of counter 50 are applied as inputs to read-only memory 44 while the four outputs of counter 52 and the A and B outputs of counter 54 are also applied as inputs to memory 44.
- the invention provides correction for coincidence error in accordance with the actual error accumulating throughout a particle counting run and on an effectively continuous basis.
- the invention in actual implementation may take a variety of forms to suit specific constructional and operational requirements without departing from the spirit and true scope of the invention. Accordingly, it is not intended to limit the invention by what has been particularly shown and described, except as indicated in the appended claims.
- a particle counting system including a transducer having an aperture through which particlecontaining liquid is caused to flow and means for generating electrical pulses in response to particles passing through said aperture, circuitry for providing correction for the coincident passage of multiple particles through said aperture, said circuitry comprising:
- memory means containing data representing predetermined particle counts at which correction is to occur; address means operative in response to said first pulses to address said memory means to cause the provision of parallel output codes therefrom;
- multiplexer means operative in response to said parallel output codes to provide at least one gating signal
- first gate means operative in response to said at least one gating signal and to said second pulses to provide a correction pulse
- second gate means operative in response to said first pulses and said correction pulse to provide output pulses representative of a corrected particle count.
- first pulse and second pulse providing means each include a multivibrator operative to provide an output pulse in response to a corresponding input pulse thereto.
- said memory means includes a read-only memory programmed with said data representing predetermined particle counts at which correction is to occur for a particularly configured metering aperture and dilution ratio of the partical-containing liquid.
- said address means includes an address register providing successive address codes in response to successive first pulses for addressing said read-only memory in accordance with the number of first pulses received.
- said first gate means includes a NAND gate coupled to said multiplexer means and to said second pulse providing means;
- said second gate means includes an OR gate coupled to said NAND gate and to said first pulse providing means.
- said memory means is a read-only memory containing data representative of said predetermined particle counts for different types of particles
- said first gate means includes first and second NAND gates operative to receive said second pulses and gating signals from said multiplexer means;
- enabling means coupled to said NAND gates and operative to enable a selected one thereof in accordance with the type of particles being counted.
- said memory means is a read-only memory containing data representative of said predetermined particle counts for different types of particles
- said multiplexer means is operative-in response to said output codes from said read-only memory to provide at least one gating signal for each of said different types of particles; and said first gate means includes first and second gates operative to receive respective ones of said gating signals and said second pulses; and
- enabling means coupled to said first and second gates and operative to enable a selected one thereof in accordance with the type of particles being counted.
- said second gate means includes an OR gate coupled to said first and second gates and to said first pulse providing means.
- said enabling means includes:
- inverter means coupling said source to said second gate.
- said memory means includes a read-only memory programmed with said data representing predetermined particle counts at which correction is to occur, said data being statistically determined in accordance with the dilution ratio of the particle-containing liquid and the transducer aperture size.
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- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Biological Materials (AREA)
- Measurement Of Radiation (AREA)
Priority Applications (11)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US447530A US3864551A (en) | 1974-03-01 | 1974-03-01 | Coincidence correction circuit |
ZA00750616A ZA75616B (en) | 1974-03-01 | 1975-01-29 | Coincidence correction circuit |
AU78082/75A AU482988B2 (en) | 1974-03-01 | 1975-02-11 | Coincidence correction circuit |
DE2505837A DE2505837C3 (de) | 1974-03-01 | 1975-02-12 | Koinzidenz-Korrekturschaltung J. T. Baker, Chemical Co, Phillips- |
GB608675A GB1468332A (en) | 1974-03-01 | 1975-02-13 | Particle counting system including a coincidence correction circuit |
JP1754875A JPS5639417B2 (xx) | 1974-03-01 | 1975-02-13 | |
CA220,075A CA1013434A (en) | 1974-03-01 | 1975-02-13 | Coincidence correction circuit |
BE153764A BE826007A (fr) | 1974-03-01 | 1975-02-26 | Circuit de correction des erreurs de coincidence dans un dispositif de comptage de particules |
ES435131A ES435131A1 (es) | 1974-03-01 | 1975-02-27 | Sistema de conteo de particulas suspendidas en un liquido. |
NLAANVRAGE7502387,A NL168333C (nl) | 1974-03-01 | 1975-02-28 | Inrichting voor het tellen van deeltjes. |
FR7506453A FR2262835B1 (xx) | 1974-03-01 | 1975-02-28 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US447530A US3864551A (en) | 1974-03-01 | 1974-03-01 | Coincidence correction circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
US3864551A true US3864551A (en) | 1975-02-04 |
Family
ID=23776728
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US447530A Expired - Lifetime US3864551A (en) | 1974-03-01 | 1974-03-01 | Coincidence correction circuit |
Country Status (10)
Country | Link |
---|---|
US (1) | US3864551A (xx) |
JP (1) | JPS5639417B2 (xx) |
BE (1) | BE826007A (xx) |
CA (1) | CA1013434A (xx) |
DE (1) | DE2505837C3 (xx) |
ES (1) | ES435131A1 (xx) |
FR (1) | FR2262835B1 (xx) |
GB (1) | GB1468332A (xx) |
NL (1) | NL168333C (xx) |
ZA (1) | ZA75616B (xx) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3938038A (en) * | 1974-07-01 | 1976-02-10 | Coulter Electronics, Inc. | Method and apparatus for providing primary coincidence correction during particle analysis |
US3944791A (en) * | 1974-07-10 | 1976-03-16 | General Science Corporation | Platelet count correction circuit |
US3978727A (en) * | 1973-11-09 | 1976-09-07 | Griverus Tor L B | Method and device for correcting the output signal from a digital transducer for measuring a physical magnitude or variable |
US4042808A (en) * | 1975-08-11 | 1977-08-16 | Angel Engineering Corporation | Particle count correction |
US4366372A (en) * | 1979-06-01 | 1982-12-28 | Innovative Design, Inc. | Apparatus and method for counting repetitive marks on a running web |
US4414678A (en) * | 1975-10-25 | 1983-11-08 | Dr. Johannes Heidenhain Gmbh | Electronic up-down conting system with directional discriminator |
US4447883A (en) * | 1981-05-26 | 1984-05-08 | Technicon Instruments Corporation | Coincidence-error correcting apparatus and method |
US20080315860A1 (en) * | 2007-06-19 | 2008-12-25 | Jean-Marc Reymond | Device and method for counting elementary particles emitted by a fluid in a conduit |
US20090219529A1 (en) * | 2006-05-05 | 2009-09-03 | Parsum Gmbh | Method and apparatus for determining the particles contained in a particle stream |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5598333A (en) * | 1979-01-22 | 1980-07-26 | Toa Medical Electronics Co Ltd | Particle counting device |
JPS59125931U (ja) * | 1983-02-10 | 1984-08-24 | 近藤 祐二 | 洋服の肩パツド |
JPS60314U (ja) * | 1983-06-15 | 1985-01-05 | 岩崎産業株式会社 | 成形肩パツト |
JPS61113806A (ja) * | 1984-11-07 | 1986-05-31 | 丸善工業株式会社 | 肩当パツトの製造方法 |
JPS62170507A (ja) * | 1986-01-22 | 1987-07-27 | 北岸 茂 | 肩当パツトの製造方法 |
JPS63115027U (xx) * | 1987-01-14 | 1988-07-25 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3209130A (en) * | 1962-04-30 | 1965-09-28 | Westinghouse Electric Corp | Digital measuring device |
US3686665A (en) * | 1969-12-31 | 1972-08-22 | Leeds & Northrup Co | Digital function generator |
-
1974
- 1974-03-01 US US447530A patent/US3864551A/en not_active Expired - Lifetime
-
1975
- 1975-01-29 ZA ZA00750616A patent/ZA75616B/xx unknown
- 1975-02-12 DE DE2505837A patent/DE2505837C3/de not_active Expired
- 1975-02-13 GB GB608675A patent/GB1468332A/en not_active Expired
- 1975-02-13 CA CA220,075A patent/CA1013434A/en not_active Expired
- 1975-02-13 JP JP1754875A patent/JPS5639417B2/ja not_active Expired
- 1975-02-26 BE BE153764A patent/BE826007A/xx not_active IP Right Cessation
- 1975-02-27 ES ES435131A patent/ES435131A1/es not_active Expired
- 1975-02-28 FR FR7506453A patent/FR2262835B1/fr not_active Expired
- 1975-02-28 NL NLAANVRAGE7502387,A patent/NL168333C/xx active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3209130A (en) * | 1962-04-30 | 1965-09-28 | Westinghouse Electric Corp | Digital measuring device |
US3686665A (en) * | 1969-12-31 | 1972-08-22 | Leeds & Northrup Co | Digital function generator |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3978727A (en) * | 1973-11-09 | 1976-09-07 | Griverus Tor L B | Method and device for correcting the output signal from a digital transducer for measuring a physical magnitude or variable |
US3938038A (en) * | 1974-07-01 | 1976-02-10 | Coulter Electronics, Inc. | Method and apparatus for providing primary coincidence correction during particle analysis |
US3944791A (en) * | 1974-07-10 | 1976-03-16 | General Science Corporation | Platelet count correction circuit |
US4042808A (en) * | 1975-08-11 | 1977-08-16 | Angel Engineering Corporation | Particle count correction |
US4414678A (en) * | 1975-10-25 | 1983-11-08 | Dr. Johannes Heidenhain Gmbh | Electronic up-down conting system with directional discriminator |
US4366372A (en) * | 1979-06-01 | 1982-12-28 | Innovative Design, Inc. | Apparatus and method for counting repetitive marks on a running web |
US4447883A (en) * | 1981-05-26 | 1984-05-08 | Technicon Instruments Corporation | Coincidence-error correcting apparatus and method |
US20090219529A1 (en) * | 2006-05-05 | 2009-09-03 | Parsum Gmbh | Method and apparatus for determining the particles contained in a particle stream |
US8345236B2 (en) * | 2006-05-05 | 2013-01-01 | Parsum Gmbh | Method and apparatus for determining the particles contained in a particle stream |
US20080315860A1 (en) * | 2007-06-19 | 2008-12-25 | Jean-Marc Reymond | Device and method for counting elementary particles emitted by a fluid in a conduit |
US7821248B2 (en) * | 2007-06-19 | 2010-10-26 | Commissariat A L'energie Atomique | Device and method for counting elementary particles emitted by a fluid in a conduit |
Also Published As
Publication number | Publication date |
---|---|
BE826007A (fr) | 1975-06-16 |
NL7502387A (nl) | 1975-09-03 |
FR2262835A1 (xx) | 1975-09-26 |
GB1468332A (en) | 1977-03-23 |
CA1013434A (en) | 1977-07-05 |
AU7808275A (en) | 1976-08-12 |
JPS5639417B2 (xx) | 1981-09-12 |
JPS50120880A (xx) | 1975-09-22 |
DE2505837C3 (de) | 1979-07-26 |
FR2262835B1 (xx) | 1979-06-08 |
NL168333C (nl) | 1982-03-16 |
DE2505837A1 (de) | 1975-09-25 |
DE2505837B2 (de) | 1978-11-16 |
ZA75616B (en) | 1976-01-28 |
NL168333B (nl) | 1981-10-16 |
ES435131A1 (es) | 1977-02-01 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BAKER INSTRUMENTS CORPORATION 100 CASCADE DRIVE, A Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:J.T. BAKER CHEMICAL COMPANY, A CORP. OF NJ;REEL/FRAME:004142/0945 Effective date: 19830413 |