US3827805A - System for controlling centrifugal forces to produce cellular monolayers - Google Patents
System for controlling centrifugal forces to produce cellular monolayers Download PDFInfo
- Publication number
- US3827805A US3827805A US00363434A US36343473A US3827805A US 3827805 A US3827805 A US 3827805A US 00363434 A US00363434 A US 00363434A US 36343473 A US36343473 A US 36343473A US 3827805 A US3827805 A US 3827805A
- Authority
- US
- United States
- Prior art keywords
- light detector
- light
- motor
- source
- scattered
- 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
- 230000001413 cellular effect Effects 0.000 title description 3
- 239000000758 substrate Substances 0.000 claims description 20
- 239000006285 cell suspension Substances 0.000 claims description 17
- 238000009987 spinning Methods 0.000 claims description 8
- 210000004369 blood Anatomy 0.000 description 22
- 239000008280 blood Substances 0.000 description 22
- 210000004027 cell Anatomy 0.000 description 15
- 210000000601 blood cell Anatomy 0.000 description 5
- 210000000265 leukocyte Anatomy 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 239000002356 single layer Substances 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000007480 spreading Effects 0.000 description 2
- 238000003892 spreading Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 210000003743 erythrocyte Anatomy 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005534 hematocrit Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 210000005259 peripheral blood Anatomy 0.000 description 1
- 239000011886 peripheral blood Substances 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/2813—Producing thin layers of samples on a substrate, e.g. smearing, spinning-on
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/2813—Producing thin layers of samples on a substrate, e.g. smearing, spinning-on
- G01N2001/2846—Cytocentrifuge method
Definitions
- ABSTRACT A control system for a slide centrifuge includes a source of light imaged through the slide. A direct light detector and a scattered light detector detect the light. The ratio of the outputs of the two detectors is a signal which is proportional to the spacing of the cells on the slide. The centrifuge motor is stopped when equality occurs between this ratio signal and a decaying signal.
- This invention relates to control systems for cell smear slide centrifuges, and more particularly to a control system which stops the spinning after an optimum time period which produces a good monolayer of cells.
- Spinning the microscope slides wetted with blood is an effective method for preparing a monolayer blood smear which can be automatically processed. Because there is a variation of blood properties, the spin time must be changed in order to produce the best quality blood smears.
- the copending application of our coworkers, Ser. No. 363,433, filed May 24, 1973, Blood Smeared Slide Centrifuge discloses a centrifuge in which the spin time is adjusted in accordance with the percent hematocrit of the blood.
- the spreading apart of the blood cells is monitored as the spin proceeds and the centrifuge motor is stopped at a favorable moment determined by cell spreading and by elapsed time. In this way, the control of the spin is automatically adapted to the blood sample.
- a source of light is imaged through the blood-wetted slide.
- the ratio of the outputs of a direct light detector and a scattered light red cells For such blood samples, the best compromise is obtained at spin times giving closer packed cells than for low red blood cell content samples. Because of this, the ratio of direct light and scattered light is compared to an exponentially decaying signal. At the time there is an equality between the ratio signal and the exponentially decaying signal, the centrifuge motor is stopped. In this manner, a good monolayer blood smear is obtained without damage to the blood cells which might otherwise be caused by too long a spin time.
- This apparatus may be used to make smears from cell suspensions other than blood.
- FIG. 1 shows the basic principle of monitoring the ratio of the direct light to the scattered light
- FIG. 2 is a top view of the platen in the preferred embodiment
- FIG. 3 is a side view of the preferred embodiment
- FIG. 4 depicts a modification of the invention
- FIGS. 5A and 58 together show the circuitry for producing the signal which stops the motor.
- FIG. 6 shows the motor driver circuit
- the output of the direct light detector 16 represents the clear area between the cells within the illuminated area of the slide, but this output has other components.
- the output of the direct light detector 16 is influenced by a dirty optical system, or by the intensity of the light source 1 l.
- the output of the scattered light detector 18 is representative of the cumulative area of, and therefore the number of, blood cells within the illuminated area of the slide.
- the output of scattered light detector 18 is also influenced by other components, such as dirt in the optical system or by the intensity of the light source 11. Cancellation of the undesirable signal components is obtained by using the ratio between the direct light detector output and the scattered light detector output to represent the blood cell spacing.
- the outputs of the two detectors are shown applied to the ratio computation circuit 19 which will subsequently be described in more detail with reference to FIGS. 5A and 5B.
- FIGS. 2 and 3 show the preferred arrangement of the detectors and light source in relation to the platen 20.
- the light from the source 11 is imaged through two holes 21 in the platen. These two holes provide a large area which can be sampled by the light.
- As the platen spins two wide arcs centered on the spin center are illuminated. The sampling of a large area such as this prevents small anomalies in the smear from having an unduly large control effect.
- As the platen rotates light is intermittently incident upon the detectors l6 and 18. This intermittent action provides a chopper effect and the chopped signals can be precisely processed by the electronics, even if ambient light leaks into the detector, and even if the detector preamplifiers have a DC drift.
- This chopper action also produces an electrical signal of a frequency determined by the spin speed. This electrical signal is available in the electronics system and can be used for spin speed control if desired.
- the centrifuge is mounted in a housing which has a lid 22 for access to the platen.
- the lid 22 is hinged at 23.
- the light source 11 is mounted in a recess in the lid and light passes through the pinhole 24 onto the platen.
- the detectors 16 and 18 are also mounted in the lid. This arrangement provides a convenient and practical mounting for the detectors, light source and lens on the same rigid structure, thereby maintaining a good alignment between them. Also, by mounting the optics on the lid, opening the lid affords easy access for cleaning.
- the light source 11 is a continuously visible light emitting diode.
- FIG. 4 shows a modification in which light from a collimated source 28 is directed through the hole 29 in the hollow motor shaft 30.
- a portion of the light beam passes directly through the slide 13 and the blood smear. This light is reflected by beamsplitter 32 to the direct light detector 33. Some of the scattered light passes through the beamsplitter 32 to the scattered light detector 34. Light passing directly through the slide 13, the blood smear, and the beamsplitter 32 is obstructed by the direct light stop 35.
- FIGS. A and 5B show the circuitry for stopping the centrifuge motor at the correct time.
- the photo cells 16 and 18 intercept the direct and scattered light.
- the signals from these two detectors are amplified by the preamplifiers 36 and 37. Further amplification is provided by tuned AC amplifiers 62 and 63 which are tuned to the frequency at which the light is intermittently incident upon the detectors by reason of the light-chopping action.
- the amplified signals are rectified in the rectifiers 38 and 39 and are filtered in the low pass filters 40 and 41 to produce a signal D proportional to the instantaneous direct light and a signal S proportional to the instantaneous scattered light.
- a compensation for the scattered light not due to the blood smear is applied through the resistor 42.
- the circuitry produces a signal which stops the centrifuge motor when the ratio D/S equals a decaying threshold. signal.
- the decaying threshold signal Ae is empirically adjusted to give a good slide appearance for various blood types.
- Resistor 45 is used to set the time constant T and a scale factor adjustment in the multiplier 46 has the effect of adjusting the factor A. It is a feature of the invention that once having set up the system, no further adjustment is needed, even when widely different blood types are to be smeared.
- a threshold voltage generator including transistor 43, capacitor 44, and resistor 45 produces the decaying threshold signal. .T he time constant T of the decaying threshold signal is the product of resistance 45 and capacitance 44.
- the decaying threshold signal is applied to the multiplier 46.
- the decaying threshold signal is multiplied by the output of the scattered light detector.
- the product is applied to the comparator 47 where it is compared to the output of the direct light detector. When the two levels become equal,
- the comparator changes from the motor run state to the motor stop state. Therefore, the comparator produces a stop signal when The flip-flop 48 is set when the start button 49 is depressed. This applies a positive potential to transistor 52 which starts the centrifuge motor.
- the inverter 50 provides a 200-millisecond delay interlock. This prevents the light monitor circuit from turning the motor off during the first 200 milliseconds, thereby allowing time for the blood film to form and the sensors to detect the proper light levels.
- the NOR circuit 51 resets the flip-flop 48, thereby stopping the centrifuge motor.
- a potentiometer 53 in the emitter circuit of output transistor 52 allows the level of the output to the motor driver to be adjusted to control motor speed.
- FIG. 6 shows the motor drive circuit.
- the input to this circuit comes from the control circuit of FIG. 5.
- the input is applied to the non-inverting input of amplifier 54 whose output drives the DC motor 55 via the power amplifying transistors 58 and 59.
- a feedback signal proportional to motor speed and substantially independent of motor current is formed at the inverting input of amplifier 54.
- Amplifier 54 has a high gain to differential input signals so that the input has to be almost exactly matched by the feedback signal, causing the motor speed to be controlled by the input signal.
- the potential from the motor input to ground consists primarily of back EMF which is directly proportional to motor speed and iR drop due to current flow through the various resistive portions of the motor circuit.
- Motor current flows through resistor 62, generating a potential drop across this resistor directly proportional to the 1R drop in the motor circuit.
- Amplifier 56 with its two associated resistors produces an output signal directly proportional to the negative of the iR drop in the motor circuit.
- Resistors 57, 60, and 61 combine the output of amplifier 56 and the potential applied to the motor circuits so that the feedback signal applied to amplifier 54 is independent of motor current and has a convenient scale factor relating motor speed and feedback potential.
- the input to the circuit of FIG. 6 goes positive. This turns on transistor 58 to provide a high potential surge that brings the motor 55 up to a desired speed in a short period of time.
- the back EMF of the motor is used as a feedback signal proportional to actual motor speed.
- This motor speed signal is applied in a feedback loop which controls the motor spin speed.
- the transistor 59 is turned on. This applies a reverse polarity current to the motor 55 to bring the motor to a stop in a short period of time.
- the system of this invention automatically controls spin time of the centrifuge.
- the spin time is manually changed. It will be appreciated that in many instances it will be desirable to provide both types of control.
- an automatic timing system as disclosed in this invention with a manual override by which the spin time can be manually set.
- a control system for a centrifuge for spinning transparent substrates wetted with cell suspensions comprising:
- a direct light detector positioned to detect light transmitted from said source directly through said transparent substrate
- a scattered light detector positioned to detect light from said source which is scattered by the cell suspension covering said transparent substrate
- a control system for a centrifuge for spinning transparent substrates wetted with cell suspensions comprising:
- a direct light detector positioned to detect light transmitted from said source directly through said transparent substrate
- a scattered light detector positioned to detect light from said source which is scattered by the cell suspension covering said transparent substrate
- a platen having holes therein, said transparent substrate being positioned on said platen over said holes, said light source being directed through said holes so that light is intermittently incident upon said detectors as said platen rotates.
- a housing for said centrifuge having a lid to provide access to said centrifuge, said light source, said direct light detector and said scattered light detector being mounted on said lid.
- an amplifier for the output of said scattered light detector tuned to the frequency at which light is intermittently incident upon said scattered light detector.
- said means for stopping said motor including a comparator, the output of said direct light detector and the output of said multiplier being applied to said comparator, said comparator producing a signal which stops said motor when the output of said direct light detector equals the product of said scattered light detector and said exponentially decaying potential.
- control system includes:
- variable resistance for adjusting the decay rate of said potential to correspond to the class of cell suspension on the slide.
- a hollow shaft for driving said platen from said motor, said light source being directed through the hole in said hollow shaft and through said slide to said detectors.
Landscapes
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Centrifugal Separators (AREA)
- Investigating Or Analysing Biological Materials (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Priority Applications (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US00363434A US3827805A (en) | 1973-05-24 | 1973-05-24 | System for controlling centrifugal forces to produce cellular monolayers |
ES423084A ES423084A1 (es) | 1973-05-24 | 1974-02-09 | Sistema controlador de fuerzas centrifugas para producir capas monomoleculares. |
CA194,159A CA1021436A (en) | 1973-05-24 | 1974-03-05 | Control system for a blood smeared slide centrifuge |
DE2423203A DE2423203A1 (de) | 1973-05-24 | 1974-05-14 | Vorrichtung zum einstellen und regeln von zentrifugen |
JP49057227A JPS5846696B2 (ja) | 1973-05-24 | 1974-05-21 | 細胞懸濁液でぬれた透明基板を回転させる遠心機の制御装置 |
IT23082/74A IT1012741B (it) | 1973-05-24 | 1974-05-22 | Sistema di controllo delle forze centrifughe per la produzione di monostrati cellulari |
CH707974A CH587681A5 (es) | 1973-05-24 | 1974-05-22 | |
GB2277774A GB1466766A (en) | 1973-05-24 | 1974-05-22 | Control systems for cell smear slide centrifuges |
FR7417876A FR2230418B1 (es) | 1973-05-24 | 1974-05-22 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US00363434A US3827805A (en) | 1973-05-24 | 1973-05-24 | System for controlling centrifugal forces to produce cellular monolayers |
Publications (1)
Publication Number | Publication Date |
---|---|
US3827805A true US3827805A (en) | 1974-08-06 |
Family
ID=23430199
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00363434A Expired - Lifetime US3827805A (en) | 1973-05-24 | 1973-05-24 | System for controlling centrifugal forces to produce cellular monolayers |
Country Status (9)
Country | Link |
---|---|
US (1) | US3827805A (es) |
JP (1) | JPS5846696B2 (es) |
CA (1) | CA1021436A (es) |
CH (1) | CH587681A5 (es) |
DE (1) | DE2423203A1 (es) |
ES (1) | ES423084A1 (es) |
FR (1) | FR2230418B1 (es) |
GB (1) | GB1466766A (es) |
IT (1) | IT1012741B (es) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4084902A (en) * | 1976-07-26 | 1978-04-18 | Green James E | Method and apparatus for producing a suspension of biological cells on a substrate |
US4129381A (en) * | 1976-10-28 | 1978-12-12 | Miles Laboratories, Inc. | Apparatus and method for preparing a particle suspension |
US4183973A (en) * | 1978-04-12 | 1980-01-15 | Corning Glass Works | Control system for a slide centrifuge |
US4248174A (en) * | 1979-03-19 | 1981-02-03 | Corning Glass Works | Control system for a slide centrifuge |
US4586190A (en) * | 1982-11-19 | 1986-04-29 | Shimadzu Corporation | Blood cell discriminator and counter utilizing transmitted and scattered light |
US4684252A (en) * | 1982-12-01 | 1987-08-04 | Hitachi, Ltd. | Automated analyzing apparatus |
US20050070020A1 (en) * | 2003-09-30 | 2005-03-31 | Trudee Klautky | Automated cytological sample classification |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56129960A (en) * | 1980-03-14 | 1981-10-12 | Toshiba Corp | Input and output test device for computer |
JPS61142542A (ja) * | 1985-10-21 | 1986-06-30 | Canon Inc | 記録媒体 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3572890A (en) * | 1968-11-18 | 1971-03-30 | Atomic Energy Commission | Microscope slide and spinner |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1184352A (en) * | 1966-04-12 | 1970-03-18 | Beckman Instruments Inc | Cell Identification and Selection System for Centrifuge Apparatus |
-
1973
- 1973-05-24 US US00363434A patent/US3827805A/en not_active Expired - Lifetime
-
1974
- 1974-02-09 ES ES423084A patent/ES423084A1/es not_active Expired
- 1974-03-05 CA CA194,159A patent/CA1021436A/en not_active Expired
- 1974-05-14 DE DE2423203A patent/DE2423203A1/de not_active Withdrawn
- 1974-05-21 JP JP49057227A patent/JPS5846696B2/ja not_active Expired
- 1974-05-22 GB GB2277774A patent/GB1466766A/en not_active Expired
- 1974-05-22 FR FR7417876A patent/FR2230418B1/fr not_active Expired
- 1974-05-22 CH CH707974A patent/CH587681A5/xx not_active IP Right Cessation
- 1974-05-22 IT IT23082/74A patent/IT1012741B/it active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3572890A (en) * | 1968-11-18 | 1971-03-30 | Atomic Energy Commission | Microscope slide and spinner |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4084902A (en) * | 1976-07-26 | 1978-04-18 | Green James E | Method and apparatus for producing a suspension of biological cells on a substrate |
US4129381A (en) * | 1976-10-28 | 1978-12-12 | Miles Laboratories, Inc. | Apparatus and method for preparing a particle suspension |
US4183973A (en) * | 1978-04-12 | 1980-01-15 | Corning Glass Works | Control system for a slide centrifuge |
US4248174A (en) * | 1979-03-19 | 1981-02-03 | Corning Glass Works | Control system for a slide centrifuge |
US4586190A (en) * | 1982-11-19 | 1986-04-29 | Shimadzu Corporation | Blood cell discriminator and counter utilizing transmitted and scattered light |
US4684252A (en) * | 1982-12-01 | 1987-08-04 | Hitachi, Ltd. | Automated analyzing apparatus |
US20050070020A1 (en) * | 2003-09-30 | 2005-03-31 | Trudee Klautky | Automated cytological sample classification |
EP1668338A2 (en) * | 2003-09-30 | 2006-06-14 | Cytyc Corporation | Automated cytological sample classification |
EP1668338A4 (en) * | 2003-09-30 | 2008-11-19 | Cytyc Corp | AUTOMATIC CLASSIFICATION OF CYTOLOGICAL SAMPLES |
AU2004278730B2 (en) * | 2003-09-30 | 2009-10-01 | Cytyc Corporation | Automated cytological sample classification |
US7803624B2 (en) * | 2003-09-30 | 2010-09-28 | Cytyc Corporation | Automated cytological sample classification |
Also Published As
Publication number | Publication date |
---|---|
GB1466766A (en) | 1977-03-09 |
FR2230418B1 (es) | 1978-01-27 |
DE2423203A1 (de) | 1974-12-12 |
JPS5020821A (es) | 1975-03-05 |
CA1021436A (en) | 1977-11-22 |
FR2230418A1 (es) | 1974-12-20 |
ES423084A1 (es) | 1976-05-16 |
CH587681A5 (es) | 1977-05-13 |
JPS5846696B2 (ja) | 1983-10-18 |
IT1012741B (it) | 1977-03-10 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CIBA CORNING DIAGNOSTICS CORP., MEDFIELD, MASSACHU Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CORNING GLASS WORKS, A BUSINESS CORP. OF NEW YORK;REEL/FRAME:004480/0063 Effective date: 19851115 |
|
AS | Assignment |
Owner name: CIBA CORNING DIAGNOSTICS CORP., MEDFIELD, MASSACHU Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CORNING GLASS WORKS;REEL/FRAME:004483/0427 Effective date: 19851105 |