JPH03150446A - Particle analyzing device - Google Patents

Abstract

PURPOSE:To device signal processing and to make a measurement with high accuracy by providing a detecting means which obtain plural pulse signals from an optical signal obtained by an optical detector, an arithmetic means which interpolates the pulse signals, etc. CONSTITUTION:In a signal processing system, the output of the optical detector 10 is connected to an amplifier 11, a high speed peak holding circuit 12, an A/D converter 13, a memory 14, an arithmetic processing part 15 and a data processing part 16 in order. The output of the memory 14 is connected to the optical detector 10. A scan is made with the the light beams in a direction intersecting the flow of the particle to be inspected in the fluid and the peak values of the pulse signals obtained by photodetecting the optical signals by the photodetector 10 are calculated respectively, and the maximum peak value and area integral value of the signal corresponding to one particle to be inspected are calculated from the electric signal obtained by interpolating the peak values to obtain information on the particle to be inspected. Consequently, a signal obtained when no pulse signal is inputted is considered to perform the highly accurate measurement.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is used in a flow cytometer or the like to irradiate scanning light onto test particles in a fluid, and receive the optical signal with a photodetector to detect the target particles. The present invention relates to a particle analysis device that obtains information on detected particles.

[Conventional technology] A flow cytometer is a cell suspension solution that flows at high speed.
In other words, it is a device that irradiates a sample liquid with, for example, a laser beam, detects a photoelectric signal from the scattered light, and elucidates the properties and structure of cells, and is used in fields such as cytochemistry, immunology, hematology, oncology, and genetics. used in

In conventional particle analysis devices used in flow cytometers and the like, the central part of the flow cell has a diameter of, for example, 200 μm
Laser light or other irradiation light is irradiated on test particles such as blood cells wrapped in sheath fluid and passing through a flow section with a minute rectangular cross section of 00 μm, and the resulting forward and side scattered light is measured. Optical signals determine the shape and shape of the particles being tested.
It is possible to obtain particle properties such as size and refractive index. In addition, for test particles that can be stained with fluorescent agents, important information for analyzing the test particles can be obtained by detecting the fluorescence of the test particles from side scattering light in a direction almost perpendicular to the irradiation light. can be found.

Conventionally, this type of apparatus obtains information from a test particle by detecting forward scattered light caused by the test particle crossing a fixed irradiation light beam using a photodetector. However, the position of the test particles in the flow section varies in the direction perpendicular to the flow, which deviates from the intensity distribution of the irradiation light beam, and the amount of light irradiating the test particles changes depending on the position of the test particles. The intensity is not constant and measurement tends to include errors.

Although this drawback can be compensated to a considerable extent by adopting the sheath flow method, delicate adjustment operations are essential to accurately align the center of the flow section and the center of the intensity distribution of the irradiated light beam in advance. Therefore, this adjustment operation is unnecessary,
Furthermore, in order to prevent variations in the position of the test particles in the direction perpendicular to the flow from affecting the scattered light intensity,
A particle analysis device as shown in Fig. 3, which scans an irradiated light beam in a direction perpendicular to the flow of particles to be detected using an acousto-optic device (AOD) and performs similar detection, was developed in Japanese Patent Laid-Open No. 63-195.
This is proposed in Publication No. 2.

In FIG. 3, a laser beam emitted from a laser light source 1 is scanned by an acousto-optic element 2, and irradiates one test particle flowing through a flow cell 3 while scanning it multiple times.
The scattered light is measured by a photodetector 4.

FIG. 4 shows a part of the signal processing system in this case. They are sequentially connected to the data processing section 8.

In the circuit shown in FIG. 4, the scattered light from the test particle is converted into an electrical signal by the photodetector 4, and further amplified by the amplifier 5. A pulse signal as shown in is obtained.

In the peak hold circuit 6, as shown in FIG. 5 fb), the maximum peak value M of all pulse signals for one test particle
1 is calculated, converted into a digital value by the A/D converter 7, and then transmitted to the data processing unit 8, where arithmetic processing is performed to obtain information on the particle to be detected.

Further, FIG. 6 shows another signal processing system, in which the output of the photodetector 4 is connected to an amplifier 5, an integrating circuit 9, an A/D converter 7, and a data processing section 8 in this order.

In FIG. 6, the pulse signal detected by the photodetector 4 and amplified by the amplifier 5 is calculated by the integrating circuit 9, and the integrated value of the whole pulse signal is calculated by the integrating circuit 9. After converting it into a digital value, it is transmitted to the data processing unit 8, where arithmetic processing is performed to obtain information on the particle to be detected.

[Problems to be Solved by the Invention] However, in the conventional signal processing described above, since the obtained pulse signal is directly processed, there is a risk that the integral value may include a large error, and the irradiated light Since the number of beam scans is limited, the maximum peak value Ml of the pulse signal does not necessarily match the peak value of the amount of scattered light obtained from the center of the actual particle to be inspected. Therefore,
There is a risk that the calculated peak value will be smaller than the actual peak value of the amount of scattered light, and there is a risk that the measured value will contain a large error due to both causes.

An object of the present invention is to eliminate the drawbacks of the conventional example described above, scan a light beam in a direction intersecting the flow of particles to be examined, and
The object of the present invention is to provide a particle analysis device that enables highly accurate measurements by devising signal processing.

[Means for Solving the Problems] In order to achieve the above object, in the particle analysis device according to the present invention, a light beam is scanned across test particles in a fluid in a direction intersecting the flow. In a particle analyzer that receives optical signals with a photodetector and obtains information about the particles to be detected, 1
a detection means for obtaining a plurality of pulse signals from an optical signal obtained by the photodetector based on sample particles; and interpolation of the pulse signal by obtaining the individual peak values of the pulse signals obtained by the detection means. It is characterized by having a first calculation means for processing, and a second calculation means for calculating the maximum peak value and/or area integral value of the signal processed by the first calculation means. It is.

[For use] A particle analysis device having the above configuration scans a light beam on the particles to be detected in a fluid in a direction intersecting the flow, and receives the optical signal with a photodetector to generate a pulse signal. The maximum peak value and area integral value of the signal for one test particle are calculated from the electrical signals interpolated using these peak values to obtain information about the test particle.

[Example] The present invention will be explained in detail based on the example illustrated in FIGS. 1 and 2.

FIG. 1 shows a signal processing system, in which the output of a photodetector 10 is transmitted to an amplifier 11. High-speed peak hold circuit 12, A/D converter 1
3, the memory 14, the arithmetic processing section 15, and the data processing section 16 are connected in this order. Further, the output of the memory 14 is connected to the photodetector 10.

Scattered light of a laser beam emitted from a laser light source (not shown) by the test particles is converted into an electrical signal by a photodetector 10 and amplified by an amplifier 11. This laser beam is scanned in the direction perpendicular to the flow of the sample particles, and since it scans one sample particle in the horizontal direction, the amplifier 1
1, a pulse signal as shown in FIG. 5 (al) similar to the conventional example is outputted and input to the high speed peak hold circuit 12. As shown in FIG. 2(a), the peak values PO1Pl, ..., Pn are all calculated for each pulse signal and converted into digital values by the A/D converter 13. After that, the pulse signal is sequentially stored in the memory 14. When it is detected that the pulse signal continuously shows the O value and the pulse signal of the scattered light by one test particle has ended, the pulse signal is stored in the memory 14. All the peak values PO1Pl, ..., Pn are output to the arithmetic processing section, and as shown in Fig. 2(b), interpolation processing of the pulse signal is performed from all the peak values PO1PI, ..., Pn. Since the number of times the laser beam scans one test particle is finite, it is inevitable that there will be a no-signal period in which no pulse signal is input. Interpolation processing is performed on the assumption that the pulse signal obtained when

When the laser beam is irradiated to the center of the sample particle,
The maximum peak value Ml can be obtained from the amount of scattered light, but since the number of scans is finite, the probability that this maximum peak value M1 will match the peak value of the pulse signal is low, but the maximum peak value of the continuous value signal after interpolation processing is With the value M2, the probability of matching becomes high. In addition, when calculating the area integral value from multiple pulse signals before interpolation processing, for example, even if one pulse signal contains an error, that error will have a large effect on the area integral value. When the pulse signal becomes a smooth continuous value, the error is eliminated, and the obtained area integral value is transmitted to the data processing section 16 for arithmetic processing to obtain highly accurate information.

[Advantageous Effects of the Invention 1] As explained above, the particle analysis device according to the present invention irradiates test particles in a fluid with a light beam that scans in a direction perpendicular to the flow, receives the optical signal, and obtains an optical signal. Calculate the peak value of each pulse signal for each pulse signal, use these peak values to perform interpolation processing on all signals for one test particle, and then calculate the maximum peak value and area integral value of all signals. Since the calculation takes into account the signal that should be obtained during the time when the pulse signal is not manually generated, highly accurate measurements can be made.

[Brief explanation of the drawing]

1 and 2 of the drawings show an embodiment of the particle analysis apparatus according to the present invention, FIG. 1 is a configuration diagram of a signal processing system, and FIG. 2 (at
fb) is an explanatory diagram of signal processing, Fig. 3 is a block diagram of a particle analysis device, Figs. 4 and 6 are block diagrams of a conventional signal processing system, and Fig. 5 (al fb) is a block diagram of a conventional example. FIG. 2 is an explanatory diagram of signal processing of FIG. 10 is a photodetector, 11 is an amplifier, 13 is an A/D converter, 16 is a data processing section, 12 is a high-speed peak hold circuit, 14 is a memory, and 15 is an arithmetic processing section.

Claims (1)

[Claims] 1. In a particle analyzer that scans a light beam across a sample particle in a fluid in a direction intersecting the flow, a photodetector receives the resulting optical signal and obtains information about the sample particle. a detection means for obtaining a plurality of pulse signals from an optical signal obtained by the photodetector based on the detection means; and a detection means for obtaining a peak value of each of the pulse signals obtained by the detection means and performing interpolation processing on the pulse signals. a maximum peak value and/or of a signal processed by the first calculation means;
and second calculation means for calculating an area integral value.