JPS63100351A - Particle counting device - Google Patents

Abstract

PURPOSE:To measure blood platelets which are smaller in diameter than other blood cells with high accuracy by providing a multichannel analyzer which analyzes the output obtained by time pulse height conversion after discriminating the pulse heights of electric signals from photomultipliers of system A and B. CONSTITUTION:The light from the light source 1 of the system A passes through a part close to the sample injection flow passage 3 of a cell 4 and light from the light source 1' of the system B passes through a part distant from the flow passage 3 of the cell 4. The light from the light source 1 is incident on a photomultiplier 6 and the light from the light source 1' is incident on a photomultipler 6'. Scattered light beams incident on the photomultipliers 6 and 6' are converted by amplifiers 7 and 7' into pulses, which are supplied to pulse height discriminators 8 and 9. Signals passed through the discriminators 8 and 9 are supplied to a time pulse height converter 10, which outputs the time difference as a pulse signal by regarding the signal passed through the photomultiplier 6 as a start signal and the signal passed through the photomultiplier 6' as a stop signal; and the pulse signal is supplied to the multichannel analyzer 11 to measure blood platelets which are smaller in diameter than other blood cells with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a particle counting device, and in particular, it is capable of increasing the simultaneous counting of many types of particles in a sample containing a large number of particles with different diameters and the simultaneous counting of particles with small diameters. The present invention relates to a particle counting device suitable for counting with high sensitivity.

[Conventional technology]

A conventional particle counting device, as shown in FIG. 7, has a light source 1.
Slit 2. Sample injection channel 3. Cell 4, shielding plate 5.
Hotful 6. Amplifier 7. Wave height discriminator 8, 13, 14. It consists of counters 12, 15, and 16. The sample containing particles with different diameters is diluted to a certain ratio with physiological saline, and then passed through the sample injection channel 3 to the cell 4.
As shown in FIG. 8, the particles pass one by one at a constant speed. Light of a specific wavelength from the light source 1 enters the cell 4 perpendicularly, hits particles within the cell 4, and is scattered. The scattered light enters the photomultiplier 6 and is detected. The light that travels straight without hitting the particles is blocked by the shielding plate 5. The light incident on the photomultiplier 6 is converted into an electric signal, and the electric signal is further converted into a pulse in the amplifier 7, and the height of the pulse is proportional to the magnitude of the electric signal. Finally, there is a correlation between the height of the pulse and the diameter of the particle, and by dividing the pulse height and counting the number of pulses per certain period of time, the number of particles for each diameter in the sample can be calculated.

The pulses are input to wave height discriminators 8, 13.14, and only pulses with heights within a certain range pass through the wave height discriminators 8, 13, 14, and the number of particles is counted by counters 12, 15, 16, respectively. . In the case of a blood cell counter, the sample is blood, and the pulse height discriminators 8, 13, 14 are for platelets, red blood cells, and white blood cells, respectively, and the pulse height discriminators 8, 13, 14 are set at a height that allows the pulse to pass according to the diameter of each. It is set to . Counter 12 for the number of white blood cells, red blood cells, and platelets
, 15 and 16, respectively, by counting the number of pulses that have passed through the pulse height discriminator 8, 13, and 14.

White blood cells (diameter 10-20 μm2 7000 pieces/IIE
II3) Red blood cells (diameter 6-10 μm2 5 million pieces/
mn5), platelets (diameter 2-4 μm, number 200,000/m
++') There is a significant difference in both the diameters and the number of pieces.

When measuring with a blood cell counter, the particle size of red blood cells is constant and the number is large, so measurement is easy.

Although the number of white blood cells is small, their particle size is large, so they are easy to measure. However, since platelets have a smaller diameter than white blood cells and red blood cells, the scattered light is small and the height of the pulse output from the amplifier 7 is also small, making them susceptible to noise. However, noise was generated due to the passage of coexisting red blood cells and white blood cells, making it difficult to accurately count platelets. 1. As a publicly known example, JP-A-60-20
There is a publication No. 9147.

[Problem that the invention seeks to solve]

In the conventional particle counting device described above, it is difficult to simultaneously count large diameter particles and small diameter particles in a sample containing two different types of particles.

In particular, in a blood cell counter in a particle counting device, - The blood sample is of three types: white blood cells, red blood cells, and platelets, and there are large differences in the number and diameter of particles.

In a blood cell counter, blood is diluted to a certain ratio with physiological saline, and then passed through a cell at a certain flow rate. Light of a certain wavelength is incident on the cell from a light source, and the scattered light is detected with a photomultiplier. With this mechanism, it is easy to count red blood cells and white blood cells because their diameter is larger than that of platelets, but platelets have an extremely small scattered light intensity of about 1720. There are also nozzles generated by electrical and optical systems, and if the intensity of the scattered light is small, it becomes difficult to distinguish between signal and noise, making accurate platelet counting difficult.

The purpose of the present invention is to accurately count the number of particles for each diameter, even in samples containing many particles with different diameters, not only large diameter particles but also small particles that are difficult to count accurately due to the influence of other particles. An object of the present invention is to provide a particle counting device capable of counting particles.

[Means for solving problems]

The above purpose is A, which consists of a light source, a slit, a shielding plate, a photomultiplier, an amplifier, and a wave height discriminator.

Two B series are provided, the light from the A series optical system is incident on the side of the cell closer to the sample injection channel, and the light from the B series optical system is configured to be incident on the side of the cell farther from the sample injection channel;
The electric signal from the A-series bottom terminal is passed through an amplifier,
Time to convert the time difference of each signal into signal height by inputting the signal whose wave height was discriminated by the wave height discriminator and the signal whose wave height was discriminated by the wave height discriminator after passing the electric signal from the B-series photomultiplier through an amplifier. This is achieved by a configuration that includes a wave height converter and a multichannel analyzer that analyzes the height of one output of the time wave height converter.

[Effect] After a predetermined time after detecting particles with A-series photomul
Particles are detected by a series of photomultiples, so each detected signal is converted into a pulse and input as a start pulse and a stop pulse to a time-to-wave height converter, and the output is a pulse with a height proportional to the time difference between the start pulse and stop pulse. The output from the time-to-wave height converter was analyzed using a multi-channel analyzer, with the horizontal axis representing the pulse height and the number of pulses (time difference), and the vertical axis representing the number of pulses. If the object is noise, it will be distributed with random time differences, but the signal of scattered light from particles will have a peak at a certain time lag, so this removes the influence of noise and enables highly accurate measurement of platelets. Become.

〔Example〕

Hereinafter, the present invention will be explained in detail using the embodiment shown in FIGS. 1 and 2 and FIGS. 3 to 6. FIG. 1 is a schematic diagram showing an embodiment of the particle counting device of the present invention.

In Fig. 1, 1 and 1' are light sources, 2 and 2' are slits, 3 is a sample injection channel, 4 is a cell, 5 and 5' are shielding plates, 6 and 6' are photomultipliers, and 7 and 7' are amplifier, 8,9,1
3.14 is a pulse height discriminator, and light source 1. Slit 2. Shielding plate 5. Homatru6. Amplifier 7. Wave height discriminator 8, 13.14
indicates A series, light source 1', slit 2'.

Shielding plate 5', photofluid 6', amplifier 7', wave height discriminator 9
indicates the B series, and there are two series. The light from the A series light source 1 passes through the part near the sample injection channel 3 of the cell 4, and the light from the B series light source 1' passes through the cell 4. It is arranged to pass through a portion remote from the sample injection channel 3. Cell 4 is made of glass and is elongated and has a square cross section.
Blood serving as a sample flows into the sample injection channel 3 at the bottom of the cell 4 and flows toward the top at a constant flow rate. Light from an A-series light source 1 passes through a slit 2 and enters a cell 4 perpendicularly, and the light that enters the cell 4 is scattered by white blood cells, red blood cells, and platelets in the blood and detected by an indicator 6. The unscattered light continues straight and is blocked by the shielding plate 5. The same is true for the B series, where the light from the light source 1' passes through the slit 2' and enters the cell 4 at different positions perpendicularly, is scattered by white blood cells, red blood cells, and platelets in the blood, and is detected by the photomultiplier 6'. The unscattered light continues straight and is blocked by the shielding plate 5'. Photomaru6,6'
The scattered light incident on each of them is converted into electric signals 17 and 17' as shown in FIG. 2, and further converted into pulses by amplifiers 7 and 7', respectively. The height of the converted pulse is then proportional to the magnitude of the electrical signal 17.17'.

By the way, the electric signal 17 from the photomaru 6 is shown in FIG.
It has a waveform as shown, and is input to amplifier 7.
The amplifier 7 has a certain level of 18 or less (in this embodiment, 0.
Electrical signals below 1 V) are cut off as noise. Then, the electric signal 17 is input to the amplifier 7, and after a certain period of time Δtc ('100 nsec in this embodiment) has passed since the electric signal 17 exceeds the certain detection level 18.
is converted into a pulse 19 having a voltage of . The same applies to the electric signal 17' from the photomultiplex 6'.

Next, the electric signal from the photomultiplier 6 is sent to a wave height discriminator 8.13.
．． 14, and the pulse height discriminator 8 is for white blood cells and is 6.0 to 9.
．． Ov, the wave height discriminator 13 is for red blood cells and is 4.0 to 5. O.V.
, the pulse height discriminator 14 is set to 0.2 to 0.5 V for platelets, and only pulses having magnitudes within these ranges pass through the respective pulse height discriminators 8, 13.14. The pulses passing through the pulse height discriminators 13 and 14 are respectively counted by counters 15 and 16 to measure the number of red blood cells and white blood cells.

The scattered light incident on the photomultiplier 6' is converted into an electric signal, and then the electric signal 17' is converted into a pulse in the amplifier 7', and the height of the converted pulse is proportional to the magnitude of the electric signal 17'. This pulse is input to the pulse height discriminator 9. The pulse height discriminator 9 is set to 10.2 to 0.5 V for platelets, and only pulses having a magnitude within this range are detected by the pulse height discriminator 9.
pass through.

The pulses that have passed through the pulse height discriminators 8 and 9 for platelet measurement are
The signal is input to the time pulse height converter 10, and the time pulse height converter 10 treats the signal that has passed through the photomul 6 as a start signal, the signal that has passed through the photomul 6' as a stop signal, and outputs the time difference between the start and stop as a pulse signal. do. This pulse signal is input to a multi-channel analyzer 11 (abbreviated as MCA). MCAl1
Now, the horizontal axis shows the start pulse 20 and the stop pulse 21.
The vertical axis represents the number of pulses. When detecting particles with Photomul 6', there is already a shift in Δ in terms of time and quantity compared to Photomul 6, so the peak is Δ
It will appear at a location with a difference of only a second. The total number of pulses at this peak is counted and determined as the number of platelets.

This makes it possible to prevent random noise that can be a problem when counting platelets.

According to the above-described embodiment of the present invention, in a sample containing particles having different diameters from white blood cells, red blood cells, and platelets, it is possible to measure platelets with a smaller diameter than other blood cells with high precision, in addition to white blood cells and red blood cells. Table 1 (next page) shows the results showing the reproducibility when measuring healthy human blood as a sample.

〔Effect of the invention〕

As explained above, according to the present invention, white blood cells.

A sample containing red blood cells, platelets, and particles of different diameters.
This method has the advantage that, along with white blood cells and red blood cells, platelets, which are smaller in diameter than other blood cells, can be measured with high precision.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the particle counting device of the present invention, FIG. 2 is a schematic diagram of the electric circuit and pulse waveform of FIG. 1, and FIG.
The figure is a waveform diagram of the electrical output of the photomultiplier and the pulse signal of the amplifier in figure 2, figure 4 is a time chart of the pulse output of the pulse height discriminators 8 and 9 in figure 2, and figure 5 is the waveform diagram of the pulse signal of the pulse height discriminator 8 and 9 in figure 2. FIG. 6 is a waveform diagram of the output pulse of the time waveform converter, FIG. 6 is a diagram showing the MCA output of FIG. 2, and FIG. 7 is a schematic diagram of a conventional particle counting device. 1.1'...Light source, 2,2'...Slit, 3...
・Sample injection flow path, 4...Cell, 5, 5'...Shielding plate, 6゜6'...Photometer, 7,7'...Amplifier, 8,9゜13.14... Wave height discriminator, 10... Time pulse height converter, 11... MCA, 12, 15, 16.
··counter.

Claims (1)

[Claims] 1. A particle counting device in which a light source, a slit, a cell, a shielding plate, and a photomultiplier are installed in a straight line, and is equipped with an amplifier, a pulse height discriminator, and a counter, wherein the light source, the slit, the shielding plate,
The series consisting of a photomultiplier, an amplifier, and a pulse height discriminator consists of an A series and a B series, and the light from the A series light source is incident on the side of the cell near the sample injection channel, and the light from the B series light source is incident on the side of the cell near the sample injection channel. The cell is configured so that the light is incident on the side farther from the sample injection flow path, and the electric signal from the A-series photomultiply is passed through an amplifier, and the signal from the B-series photomultiplier is differentiated by a pulse height discriminator. Input the electrical signal and the signal that has been subjected to pulse height discrimination by a pulse height discriminator via an amplifier,
1. A particle counting device comprising: a time-to-wave-height converter that converts the time lag of each signal into a signal height; and a multi-channel analyzer to analyze the height of the output of the time-to-wave-height converter.