JPH0324626B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention and Description of the Prior Art The present invention relates to an apparatus for classifying microparticles in a fluid, and in particular to an apparatus for classifying microparticles in a fluid, and in particular, a device that vibrates a jet of liquid containing particles to generate waves on the surface of the jet and The invention relates to a device in which the droplets are separated into particles, then classified according to particle characteristics and collected downstream.

Devices of the type described above may be referred to as flow cytometry and classification systems and are used for rapid analysis of blood cells and other biological cells in medical research and diagnostics. When a suitable high-frequency vibration is applied to a jet of liquid (sample) containing minute particles such as blood cells or other biological cells, the jet breaks up into minute parts containing particles. By "drip" is meant a minute portion of the particle-containing liquid that has been disrupted in this manner. Devices are known for vibrating a jet of liquid containing particles in this way, splitting this jet into droplets, and separating and classifying these droplets according to the characteristics of the particles they contain.
U.S. Patent No. 4038556, U.S. Patent No. 3963606, U.S. Patent No.
No. 3710933 and No. 3380584, “SCIENCE”
Vol. 198, published October 14, 1977, pp. 149-157, etc.

US Pat. No. 4,038,556 discloses a method and apparatus for simultaneously optically measuring several properties of each particle of a group of microparticles suspended in a liquid.

U.S. Pat. No. 3,963,606 discloses an apparatus for separating particles in a liquid according to predetermined characteristics, the electrical delay being adjusted to be equal to the time it takes the particles to exit a jet-forming hole and reach the point of breakup. A particle separation device is disclosed.

US Pat. No. 3,710,933 discloses an apparatus for automatically analyzing and classifying microparticles suspended in a liquid based on preselected predetermined characteristics.

US Pat. No. 3,380,584 discloses a particle separator in which an acoustic coupling driver is driven by an electric pulse to vibrate a particle-containing fluid.

"SCIENCE" Vol. 198, pp 149-157 discloses a flow type cell measuring device. This device measures the fluorescence from biological cells in a fluid stream at the intersection with a laser beam, and selects the drip containing the cells of interest from the fluid stream. The present invention may be better understood with reference to these patents and publications.

An important problem with the use of cell sorting devices that vibrate the jet to break it into drops is that the point at which the jet breaks into drops varies and is not constant. If the precise instant of division relative to the detection point changes, the device becomes less of a cell sorter and more of a water or saline solution containing unknown cells. That is, if the splitting point changes, an undesirable result will occur in that undesirable particles will be sorted. Such changes in the breakup point are often due to mechanical coupling coefficient changes such as air bubbles entering the flow chamber or partial blockage of the jet orifice. Also, it is not feasible to observe the break-up point of the jet during cell sorting using a strobe light source due to optical interferences such as the presence of undesired light. For this reason, current classifiers require monitors.

SUMMARY OF THE INVENTION It is an object of the present invention to measure changes in the amplitude of the waves at a point on the jet surface prior to the point of drop breakup of the suspension jet in a drop generator and to indicate when such changes occur. It is to do so.

Another object of the present invention is to automatically inhibit the classification operation of a particle analysis and classification device when a significant change in drop breakup point occurs.

Yet another object of the invention is to use the information obtained from changes in wave amplitude at a point on the surface of the jet to restore the wave amplitude level at that point to its original state.

Other objects will become apparent upon reading the following detailed description of the invention.

The jet of liquid containing suspended microparticles oscillates at a suitable frequency to generate the drip. This frequency is typically 20-40KC depending on the diameter of the jet orifice,
For example, for a 76 micron orifice, 32KC, 50
40KC for a ~60 micron orifice.
Small vibrations are applied to the jet stream by a piezoelectric crystal at the injection port. This vibration creates undulations or standing waves on the surface of the jet that grow as the jet progresses and eventually break up into drops downstream. The amplitude of the wave at any point along the jet is a function of the distance from the point of drop breakup to this point, as demonstrated by Richard Gee of the Stanford Research Institute at Stanford University. Sweet paper SEL−64−004
(March 1964). In the present invention, the amplitude of waves at a fixed point is monitored. A change in this vibration at this one point represents a change in the splitting point. The laser beam used as the irradiation source in the optical cell sorting device disclosed in the above-mentioned US patent is utilized as the focused light source in the monitoring device of the present invention. The inspection laser beam impinges on a fixed point on the jet and is scattered to produce a lobe pattern of scattered light perpendicular to the jet in the same plane as the laser beam. As is known, this scattered laser light is modulated by the surface waves of the jet. This modulation is therefore an undesirable phenomenon when measuring cellular light scattering and is usually removed in the instrument. In the present invention, a photodiode is placed within the laser light scattering plane to detect such modulation. The output of this photodiode is converted to a voltage, and this voltage is used to (1) visually or audibly notify the operator that a change has occurred in the point at which the jet breaks up into drops; (2) the jet (3) to automatically control the strength of the vibration applied to the jet to return the amplitude of the wave at the monitoring point to its original amplitude; and (3) to automatically deactivate the device. Any one or any combination of these features may be used in practicing the invention.

If necessary, a second inspection laser beam may be used in addition to the inspection laser beam.
The wave amplitude of the jet can be monitored at a point close to the drop breakup point using a focused light source. In this case, since the wave motion at this point is large, the signal obtained from this point will be large. The photodiode is then carefully positioned to receive light scattered or reflected from the jet.

One feature of the invention is a classification disabling circuit that includes a rapid change detector responsive to a rectified output having a DC level proportional to the modulation rate of a focused light beam (e.g., a laser beam) modulated by waves on the surface of the jet. Our goal is to provide the following. The change detector controls a relay driver latch mechanism that inhibits the classification operation of the particle analyzer when a significant change in the amplitude of the jet waves occurs. The circuit is provided with an operator reset device and an alarm device so that the type of change can be indicated based on the output from the change detector, if desired.

Another feature of the present invention is to provide an automatic gain control (AGC) loop system that uses a piezoelectric crystal to vary the strength of the vibrations imparted to the jet when the waves of the jet vary slowly.
The rectified output described above is used as the control voltage of the AGC loop. This loop system controls the power supplied to the piezoelectric crystal. As a result, precise amplitude correction of the waves on the surface of the jet can be obtained.
Initial setting of the drip splitting point can be performed by controlling the AGC system to inhibit operation.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Identical parts in each figure are designated by the same reference numerals.

The block diagram of FIG. 1 is divided into two parts by dashed lines 10. The components of the system to the left of the dashed line are those commonly present in a known type of particle analysis and classification system, referred to as a flow cytometry classification system. An example of such a known classification system is the TPS and EPICS series of devices manufactured and sold by Coulter Electronics of the United States. Of the various components of the particle analysis and classification apparatus, only those necessary for explaining the operation of the present invention are shown in the figure. The components to the right of the dashed line 10 constitute parts according to the invention, which can be added to and combined with known particle analysis and classification devices to achieve the object of the invention. As will become clear below, an automatic gain control (AGC) section and a classification disabling section including a relay driver latch mechanism are inserted in two places in the normal signal path of the particle analysis and classification system.

First, a known particle analysis and classification system shown to the left of dashed line 10 will be briefly described. The device comprises first means for generating a jet, which in this example comprises a flow chamber 12 into which a salt solution (typically 13p.sig) is injected under pressure and a microjet orifice 14 (for the purpose of the system). (having a diameter of 50 μm to 200 μm depending on the size) to form a jet 16 of liquid. A sample (a suspension of microparticles such as blood cells or biological cells) is injected into flow chamber 12 via tube 18 . Below the injection port 14 and above (in front of) the drip splitting point, the jet 16 is connected to a light source or a radiation source 2.
0 (typically a laser beam), and the optical response (typically scattered light and fluorescence) of the microparticles in the sample is similarly detected by a sensor system 22 in front of and above the splitting point.

At a position above the radiation source 20, the flow chamber 12 includes a single vibration means or a second means for controlling the position of the splitting point, in this example a piezoelectric crystal assembly 2.
4, which causes the chamber 12 to vibrate at a high frequency. The frequency at which the chamber 12 vibrates depends on the selected diameter of the orifice 14 and is typically between 20 and 40 KC. These vibrations create small waves on the surface of the jet 16, which propagate due to the well-known surface tension effect until they reach the breakup point 26.
The jet is split into drips 28. Figure 9 shows how this regularly vibrated jet breaks up.
The exact distance from the nozzle of injection port 14 to breakup point 26 is inversely proportional to the amplitude of the initial wave. The magnitude of this wave is proportional to the amplitude of the signal voltage applied to the piezoelectric crystal if the mechanical coupling coefficient of the system is kept constant. Unfortunately, however, there are several factors that cause changes in this mechanical coupling coefficient, and these factors are difficult to eliminate. These factors include partial blockage of the jet orifice 14 by debris such as air bubbles and cell debris trapped in the fluid in the flow chamber 12.

The piezoelectric crystal is driven by a power amplifier 30.
This power amplifier 30 takes its input signal from a frequency generator 32 via a variable potentiometer 34, so that the power amplifier 30 uses the potentiometer 34 to
The amplitude of the signal supplied to 4 can be varied,
Therefore, the regular dividing point 26 can be changed. Potentiometer 34 acts as a source of coarse correction for the power amplifier driving crystal 24. Line 36 represents the normal connection from potentiometer 34 to power amplifier 30 in the absence of the components of the present invention. The system of the present invention incorporates a switch 59, which does not exist in conventional systems, for the purpose described below.

A classification logic circuit 38 is connected to the sensor 22;
In this circuit, signals obtained from a detector (not shown but forming part of sensor 22) are applied to a set of reference circuits to determine whether particles producing these signals should be captured or not. . If the particle should be captured, the classification delay device 40 delays the decision until the particle reaches the splitting point from the detection point. A classification pulse is then formed by a classification pulse forming circuit 41, amplified by a power amplifier 43, and applied as a voltage to the jet at the point at which the droplet containing the desired particle breaks up from the jet. Due to this applied voltage, the drip breaks up in a charged state. These drops pass through a strong constant electric field, and the charged drops are deflected horizontally as they travel downward through this field. The charged drops therefore travel a different path than the uncharged drops and fall into different collection vessels, thereby achieving a physical sorting or separation of the particles. A typical classification rate for this process is 4000 particles/second. Additionally, U.S. Patent No. 3380584
The issue describes a method of charging the downstream part of a particle-containing jet for separation and collection, and "CLINICAL CHEMISTRY" vol.19, No.8,
A 1973 article by Furets, Bonner, Sweet, and Hertzenberg describes a method for applying a voltage to the upstream portion of a jet for the same purpose.

Such systems are known in the art, and the present invention does not claim this conventional method and apparatus for analyzing and classifying small particles, which are described in the aforementioned US patents and publications.

The present invention detects changes in the droplet break-up point by using the relationship between the amplitude of waves on the surface of the jet at an arbitrary fixed point and the position of the droplet break-up point.
As mentioned above, the amplitude of the wave increases as it approaches the splitting point. An increase in the amplitude of the wave at any given point along the jet indicates that the splitting point is getting closer, and a decrease in the amplitude indicates that the splitting point is moving farther away. The apparatus of the present invention monitors the location of the splitting point and performs any one of three effects: (1) Changes in the splitting point are reported visually by a meter or audibly by an alarm. (2) Prohibit classification processing and sound an alarm when a rapid change occurs in the splitting point. (3) When the change in the splitting point is small and slow, the splitting point is automatically and quickly returned to its original position using an automatic gain control loop.

The system components to the right of the dashed line 10 in the block diagram of FIG. jet stream 16
A detection device including a photodiode or detector 44 for detecting the light scattered by the photodiode or detector 44 is provided. FIG. 10 shows an enlarged view of the non-electronic components of the system component to the left of the dashed line 10 in the block diagram of FIG. This scattered light has two components: a DC component that is proportional to the size of the jet 16 and the power of the light beam 20 (e.g. a laser), and a DC component that is proportional to the size of the jet 16 and the power of the light beam 20 (e.g. a laser); Proportional to the wave and the power of the inspection light beam 20 (laser)
It has an AC component. Diode 44 operates in current mode, ie, is terminated with low impedance, to produce a linear optical power-current relationship and reduce the effects of diode capacitance for maximum bandwidth. Photodiode 44 is coupled to a split point controller that includes an operational amplifier 46 . This amplifier 46 operates as an impedance conversion amplifier and linearly converts the current from diode 44 into a voltage. The output from this amplifier 46 is connected to an AC path including an AC amplifier 48 and a DC path including a DC amplifier 50.
Split into DC paths.

The AC path is the basic information used to implement the present invention,
That is, it includes the amplitude of waves on the jet. Since the amplitude of the wave signal generated by the photodiode detector 44 is small, this signal is amplified by an AC amplifier 48 with an amplification factor of about 10 ³ . To improve the signal-to-noise ratio of this AC path, the bandwidth of the AC amplifier is limited to the range of frequencies of the drive signal provided to the piezoelectric crystal 24.

Since the size of the jet 16 remains constant during the sample particle test run and rarely changes, the DC
The component is proportional to the size of jet 16 and the power of laser 20, and changes in the DC level of the path including DC amplifier 50 can be considered as changes in laser power. The signal from the DC path controls the gain of voltage-controlled gain amplifier 52 in the AC path to normalize the AC path signal with respect to laser power, resulting in the need to recalibrate the system each time the power of laser 20 changes. Make sure there are no. The output of the DC path can also be used in another way to remove the effects of changes in laser power from the measured distance from the detection point 21 to the splitting point 26.

The AC signal from the voltage control amplifier 52 is passed through the rectifier 5
4 (preferably a full-wave rectifier) to be proportional to the amplitude of the waves on the jet 16 and at the detection point 21.
A DC signal is generated on lead wire 56 that is proportional to the distance from to split point 26. FIG. 8 shows details of an example of a suitable full-wave rectifier that can be used for this purpose.

The present invention uses the DC voltage on lead 56 in three ways. The simplest use is to drive the modulation rate meter 58 to provide a visual indication of the location of the split point 26 of the jet 16. By properly calibrating, such a meter 58 can be used to manually adjust the reference setting means or adjustable potentiometer 34, and the AGC system described below can be implemented using the regular connection line 36 of known analytical classifiers. Bypassing allows the split point 26 to be manually set. The meter 58 is always connected so that it can be used at all times.

DC voltage on lead 56 (output of rectifier 54)
is used as the control voltage for the automatic gain control (AGC) loop, which finely corrects the power amplifier 30 that energizes the piezoelectric crystal transistor 24 via the connection line 60 to finely correct the drift of the splitting point 26. can be done. This AGC
Of course, when the loop is used, the regular connection line 36 is disconnected by the switch 59. this
The AGC loop has an output terminal 65, an input terminal 69, and a control terminal 71, and the voltage on the lead wire 56 is supplied via the lead wire 66.
An amplifier 64 is provided, which is configured similar to the circuit of voltage controlled gain amplifier 52 as shown in FIG. A suitable double pole single throw switch 59 is connected between leads 36 and 37. When it is necessary to initialize the particle analysis and classification system to a specific drip delay time, switch 59 disconnects the AGC loop from the system. After the proper delay time is set, the AGC system 64 is activated to maintain the desired split point. Before driving AGC, output terminal V ₀
(lead wire 37) voltage with potentiometer 67
The amplitude is adjusted to be the same as that of the voltage on the regular connection line 36 using the zero meter 68, and after that, the switch 59 is turned on to switch the control of the power amplifier 30 to the AGC system. From the above, the splitting point control device includes amplifiers 46, 48, 50 and 52, rectifier 54,
The detection device includes a control device 64 and a reference setting means 34, and the detection device includes such a split point control device and a detector 44.

Another method of monitoring the break-up point 26 of the jet 16 is with a system that includes a rapid change detector 70 that is supplied with a rectified output voltage on the lead 56. The output 80 of the rapid change detector 70 is zero when the detector is supplied with a DC signal (when the position of the split point 26 is constant);
It changes from zero when there is a "rapid" change in the position of . The polarity of the change in the output of rapid change detector 70 represents an increase or decrease in the current output signal from rectifier 54. The output from this detector 70 can drive an alarm circuit 72 to alert an operator to changes in the splitting point. This same output also activates a relay system comprising driver latch mechanism 76, thereby controlling connection 78 to automatically disable the classification system portion of the particle analysis and classification system. Operator reset 74 is for manually resetting driver latch mechanism 76. The alarm 72 may also be capable of indicating the type of breakpoint change (polarity) based on the polarity of the output from the detector 70.

FIG. 2 shows an example of a possible electrical circuit for rapid change detector 70. FIG. Both an audio alarm 72 and a visual alarm 71 are shown in FIG.
Changes in the signal on lead 56 are coupled to amplifier 70 via capacitor C ₁ . This AC signal is amplified and supplied to lead wire 80. When the signal on lead wire 56 is a constant DC value, lead wire 80 is at approximately zero potential. Lead 80 is connected to two comparators 77 and 79 which detect the polarity of the change in the signal on lead 80 from zero potential. At this time, a small guard band is used in consideration of the offset of the amplifier. When the signal on lead 80 changes, the corresponding comparator detects the change and switches states. This switching is done by latch 81.
is detected and latched. The output of latch 81 disables the NAND gate in gate circuit 78, cutting off the classification signal. This output of latch 81 also drives visual alarm 71 and audio alarm 72. The values of capacitor C ₁ and resistor R ₁ are chosen for their speed of change, and resistors R ₁ and R ₂ are chosen for their sensitivity to change.

FIG. 4 shows the circuit of the impedance transforming preamplifier of FIGS. 1 and 3. Figure 5 shows the first and third
The circuit of the AC amplifier 48 shown in the figure is shown. Figure 6 is the first
and the circuit of the DC amplifier 50 of FIG. 3. 7th
The figure shows the circuit of the voltage controlled gain amplifier 52 of FIGS. 1 and 3. FIG. 8 shows the circuit of the full wave rectifier 58 of FIGS. 1 and 3.

To further explain FIGS. 11 to 14,
The figure shows in detail the position of the photodiode detector 44, which is located in the scattering plane and in the Y-Z plane, in particular radially relative to the jet axis 104 and The scattering surface (X-Y plane) is shown in the figure.
Only one of the scattered rays is shown. Especially the first
As shown in FIG. 2, the laser beam 20 is generally twice the width of the jet 16, and its intensity distribution is Gaussian. Additionally, the laser beam 20 itself is generally elliptical in shape with a major axis and a minor axis, with the major axis located within the scattering surface 108 and perpendicular to the jet axis 104 and with its minor axis located within the jet axis 104. is focused parallel to. In FIG. 12, the central axis 110 of the laser beam is the axis 10 of the jet 16.
It is shown that it intersects with 4. A portion of the inspection laser beam 20 is transmitted to the jet 16 at the detection point 21.
The remaining portion of the laser beam collides with the jet 16 and passes through without colliding with the jet 16. This portion of the laser beam that does not collide with the jet 16 and passes without colliding with it is referred to as "direct" light or non-colliding light. The impinging light generates scattered light having a lobe pattern, and the scattered light includes reflected light, diffracted light, and refracted light, all of which originate from the jet 16, and it is mainly the diffracted light that is detected by the photodiode 44. be. A more detailed description of the light scattering technology used in particle size flow systems can be found in the Flow
"Cytometry And Sorting", edited by Melamud, Mulanney and Mendelsohn, published by John Willey and Sons (1979), Chapter 5. Next, as shown in FIGS. 13 and 14, the detection point 21 is located upstream of the drip splitting point 26,
In this position, the surface waves of the jet 16 have a substantially round shape when viewed from the side, and therefore act as a weak positive or negative lens. As a result, the light rays incident on the surface of the jet 16 and scattered by the jet are slightly converged and diverged along the vertical axis (Z-axis). This effect is the first
Although only the refracted light of the scattered light is shown in FIGS. 3 and 14, the effect is the same for reflected light and diffracted light.

As mentioned above, the photodiode 44 and the light source 20 can be moved to a position close to the droplet breakup point 26, that is, a position where the wave motion is large, but the jet 1
It is impossible to approach the splitting point 26 beyond a position where the amplitude of the wave of the jet 16 disappears, that is, a position where the output signal from the photodiode 44 is no longer proportional to the amplitude of the wave of the jet 16. The portion of the jet 16 in which such amplitude information is lost is referred to herein as the breakup region, and the entire portion of the jet 16 upstream of the actual breakup point 26 is referred to as the continuous flow portion of the jet.

The various components and their values shown in FIGS. 2-8 are merely examples, and other equivalent circuit elements and values may be used to achieve the desired results.

Various modifications and changes can be made to the present invention. For example, DC path 50 may be omitted in a simplified embodiment of the invention since it is AC path 48 that contains the basic information regarding the amplitude of the waves on the jet.

Although the present invention has been described above with reference to specific embodiments to the extent that those skilled in the art can realize it, the present invention is not limited thereto, and can be realized in various forms as described in the claims. It's something you get.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electrical circuit embodying the present invention coupled to a known particle analysis and classification system;
Figure 2 is an electrical circuit diagram of the rapid change detector, relay driver latch mechanism, and alarm circuit of the circuit diagram in Figure 1. Figure 3 shows the signal obtained from the photodiode proportional to the modulation of the light beam by the surface waves of the jet. Figures 4 to 8 are detailed circuit diagrams showing the electric circuit of the block shown in Figure 3; Figure 9 is an enlarged side view showing the pattern of jet splitting; FIG. 10 shows the non-electrical components and detector 44 to the left of dashed line 10 in the block diagram of FIG.
11 is a diagram showing the laser light scattered from the surface of the jet 16 and detected by the detector 44 of the apparatus shown in FIGS. 1 and 10, and FIG.
The figure shows the first part of the laser beam that impinges on the detection point of the jet.
Figure 13 shows the light rays in the X-Y scattering plane in Figure 1 (the dashed line indicates the minimum diameter of the jet), and Figure 13 shows the Y-ray in Figure 11 of the laser beam colliding with the detection point of the jet when the diameter is at its maximum. Diagram showing rays in the Z plane, 14th
The figure shows the rays of the laser beam in the YZ plane of FIG. 11 that collide with the detection point of the jet when the diameter is the minimum. 12...flow chamber, 14...injection port, 16...
Jet stream, 18... Sample injection tube, 20... Light beam, 21
...Detection point, 26...Drip splitting point, 28...Drip, 22
...sensor system, 24 ... piezoelectric crystal, 30 ... power amplifier, 32 ... frequency generator, 34 ... potentiometer, 36 ... regular connection line, 38 ... classification decision logic circuit, 40 ... classification delay element, 41 ... short pulse formation Circuit, 43... Power amplifier, 44... Photodiode, 46... Impedance conversion amplifier, 48
...AC amplifier, 50...DC amplifier, 52...voltage control gain amplifier, 54...rectifier, 37, 56, 60,
66, 80... Lead wire, 58... Modulation rate meter, 59...
Double pole single throw switch, 64...AGC amplifier, 67...
Potentiometer, 68...Zero indicator, 70...Rapid change detector, 72...Alarm circuit, 74...Operator reset, 76...Relay driver latch mechanism,
78...Connection part.

Claims (1)

[Claims] 1. Generate a jet of liquid in which particles are suspended, vibrate the jet to generate waves on the surface of the jet, split the jet into droplets in the splitting region, and analyze the particles. In the method of classification and downstream collection,
A particle analysis and classification method, characterized in that waves on the surface of the jet are detected at a position before the splitting point where the jet splits into droplets, and vibrations given to the jet are controlled as a function of the amplitude of the waves at the position. . 2. In the method described in claim 1,
A particle analysis and classification method characterized in that the detection of waves on the surface of the jet includes detecting the amplitude of waves on the surface of a continuous flow portion of the jet at the detection position before the splitting region of the jet. 3. In the method described in claim 1,
A particle analysis and classification method characterized in that detecting waves on the surface of the jet generates an output proportional to the amplitude of the waves of the jet at the detection position. 4. In the method according to claim 1, 2, or 3, the detection of waves on the surface of the jet includes detecting the amplitude of waves on the surface of a continuous flow portion of the jet, and this detection is performed before the breakup region of the jet. A particle analysis and classification method characterized in that the particle analysis and classification method is achieved by light scattered in the relevant part of the particle. 5. A particle analysis and classification method according to any one of claims 1 to 4, wherein the detection position is fixed. 6. In the method according to any one of claims 1 to 4, the jet is inspected by irradiating the jet with a concentrated light beam at the detection position before the splitting point where the jet splits into drips. , extract a DC signal proportional to the amplitude of waves on the surface of the jet at the detection position from the light scattered by the jet, and use the DC signal to determine the amplitude of the vibration from the expected level of the amplitude. A particle analysis and classification method characterized by controlling according to deviation. 7. In the method according to any one of claims 1 to 4, the amplitude of the wave at the detection position is determined by adjusting the intensity of the vibration applied to the jet flow in response to a change in the amplitude of the wave at the detection position. A particle analysis and classification method, characterized in that the drift of the splitting point is prevented by automatically controlling the splitting point in the direction of returning it to its original state. 8 A jet of liquid from a liquid in which particles are suspended 1
6 and said jet stream 16;
a vibration device 24 for vibrating the jet to generate waves on the surface of the jet to break the jet into droplets at its breakup region; a second means for controlling the position of a splitting point 26 of the jet; a light irradiation device 20 for irradiating a portion with a light beam; a detection device coupled to the second means 24 that contains light scattered by a portion of the jet 16; Detection devices 44, 46 that respond to the light from the light irradiation device 20 and provide the second means with an output that is a function of the amplitude of the wave of a portion of the jet or an output that depends on the magnitude of the detected scattered light. ,48,5
A particle analysis and classification device characterized in that 0, 52, 54, 64 and 34 are provided. 9. In the device according to claim 8,
A particle analysis and classification device in which the output of the detection device is proportional to the wave amplitude of a portion of the jet. 10. The particle analysis and classification apparatus according to claim 8, wherein the light beam is irradiated onto the jet at a position 21 before the splitting region of the jet. 11. A particle analysis and classification device according to any one of claims 8 to 9, wherein the second means includes the vibration device 24. 12. A particle analysis and classification device according to any one of claims 8 to 9, characterized in that the vibration device 24 is a single device. 13. A particle analysis and classification device according to any one of claims 8 to 9, wherein the vibration device 24 is located above the light irradiation device 20. 14. In the device according to any one of claims 8 to 9, the light beam 20
A particle analysis and classification device characterized in that the particle is injected only into the continuous flow portion of No. 6. 15. In the device according to any one of claims 8 to 9, the light beam 20
6. A particle analysis and classification device characterized in that it strikes the jet only at a position before the splitting region of No. 6. 16. The device according to any one of claims 8 to 9, comprising: a detector 44 responsive to light from the light irradiation device 20 that includes light scattered by the jet 16; an input terminal coupled to said detector and said second
means 24 having an output terminal coupled to said second
a break-up point control device 46,4 for providing means with an output proportional to the amplitude of the waves in the portion of said jet;
8, 50, 52, 54, 64, and 34. 17. The apparatus according to any one of claims 8 to 9, wherein the detection device includes a detector 44 responsive to light from the light irradiation device 20 including light scattered by the jet 16; reference setting means 34 for supplying a reference signal with an amplitude proportional to the predetermined split point position of the jet; an output terminal 65 coupled to said second means 24; an input terminal 69 coupled to said reference setting means; and said detection control terminal 7 coupled to the
and a control device 64 for generating an output signal proportional to the amplitude of the waves in the examined portion of the jet.