JPH09257689A - Particle analyzer - Google Patents

Abstract

(57) Abstract: In a particle analyzer for taking a static image of particles suspended in a flowing liquid and analyzing the particles, when an abnormality is detected in a particle detection system, the operator can be promptly notified of the error. Notify an abnormality. SOLUTION: A sample is caused to flow in a flow cell 100, passage of particles is detected by a laser beam 10, a pulse lamp 1 is caused to emit light based on the detection, and a still image of particles is displayed on a TV.
An image is taken by the camera 8 and image processing is performed. Particle number analysis unit 40
The distribution of the particle detection signal intensities obtained by the photodetector circuit 22 is taken, and from the result, if there is an abnormality in the particle detection system,
Notify the operator of the equipment abnormality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle analyzer for analyzing a particle by flowing a sample solution containing a particle component such as blood or urine into a flat sheath flow, taking an image of the particle, and analyzing the particle.

[0002]

2. Description of the Related Art Conventionally, in order to examine cells in blood or cells and particles in urine, a method of observing cells and particles smear-stained on a slide glass through a microscope has been used. However, with this method, it takes time to prepare the sample, the area of the smear is limited, so many cells and particles cannot be observed, and it is necessary to move the microscope stage to find the particles. There is a problem that becomes.

On the other hand, several attempts have been made to photograph particles in a continuously flowing sample liquid and analyze the particles from particle images. For example, Japanese Patent Application Laid-Open No. Sho 57-500995,
63-94156 and JP-A-4-72544 are known.

In Japanese Patent Laid-Open Publication No. Sho 57-500995, a still image of particles of a measurement sample is obtained by flowing a measurement sample through a channel, periodically emitting a strobe in an imaging area, and photographing the image with a CCD camera. The strobe emits light periodically in synchronization with the operation of the CCD camera. Since the light emission time of the strobe is short, a still image can be obtained even when particles are continuously flowing. Further, the CCD camera can capture 30 still images per second.

In Japanese Patent Application Laid-Open No. 63-94156, an optical system for detecting particles is provided upstream of a still image capturing area in addition to an optical system for capturing a still image. When a particle traverses, the flash lamp is turned on just after the time that the particle reaches the imaging area to obtain a still image of the particle. According to this method, the flash lamp does not periodically emit light but emits light only when passage of particles is detected, so that a particle image can be efficiently obtained. Also,
There is no need to perform meaningless image processing for a sample sample having a low concentration.

Since this method can process very efficiently when the particle concentration of the measurement sample is low, it is possible to increase the amount of measurement sample, shorten the measurement time, and improve the measurement accuracy.

[0007]

The present invention has a particle detection means for detecting particles passing through a still image capturing area of a particle or the upstream thereof, and means for shooting a still image of a particle by turning on a pulse light source only when the particle passes. In the particle analyzer,
The pulse light source does not turn on unless the particle detection signal intensity obtained by the particle detection means is higher than a predetermined value. Generally, the particle detecting means includes a semiconductor laser that is a detection light source that emits laser light as detection light, a collimator lens that makes the laser light from the semiconductor laser a parallel light flux, a cylindrical lens that aggregates the laser light flux from the collimator lens, and a flow cell. It is composed of a particle detection unit or the like that receives scattered light emitted when particles cross the light flux of the semiconductor laser irradiated to the upstream position.

Since the laser beam having a predetermined value is irradiated to the position upstream of the flow cell, the particle detection section should be able to obtain the particle detection signal intensity which is sufficient for the detected particles. However, there is a case where an abnormality occurs in the semiconductor laser that is the particle detection light source, and the laser light having a predetermined value located upstream of the flow cell is not irradiated. As a result, as for the particle detection signal, the signal intensity sufficient for the detected particles cannot be obtained, the pulse light source does not turn on, and a sufficient particle still image cannot be obtained. In the particle analysis device, the particle measurement accuracy is determined by the number of particles that have undergone image processing, and thus there is a problem that the measurement accuracy deteriorates.

In the particle analyzer, the distance between the particle detection optical system and the particle static image capturing area is mechanically determined, so that the flow velocity of the measurement sample is constant, and therefore the particle detection optical system inevitably detects particles. The time it takes for the particles to pass through the still image capture area after detection is known. (Hereinafter, this time will be referred to as delay time.) If the pulse lamp is turned on after the delay time has elapsed, the particle still image is displayed on a predetermined image display unit. However, if the optical path consisting of a collimator lens that collimates the laser light from the semiconductor laser that is the particle detection light source into a parallel light flux and a cylindrical lens that aggregates the laser light flux from the collimator lens, etc. The pulse light source is turned on in the area before and after reaching the particle still image capturing area that should originally pass, and particles detected by the particle detection optical system are not imaged, resulting in wasteful image processing. As a result, problems such as deterioration of image processing efficiency occur.

[0010]

The present invention provides a method for solving the problem that an abnormality occurs in the particle detection system and a sufficient particle still image cannot be obtained, and a particle analysis apparatus using the solution is provided. It is provided.

When a sample solution containing a particle component is caused to flow in a flow cell, and an optical system for particle detection which is continuously lit at a position upstream of the sample solution flowing in the flow cell detects particles passing through the flow cell, the flow cell is detected. Consider a particle analyzer that classifies particles by illuminating an optical system that illuminates an image capturing area inside, capturing a still image of particles detected by the image capturing device, and performing image analysis on the captured particle still image.

A semiconductor laser which is a particle detecting light source is generally driven by an auto power control circuit. Since the optical output of the laser diode changes easily due to changes in ambient temperature, the auto power control circuit detects the monitor light flowing through the photodiode so that a constant optical output can be obtained even if the temperature changes. It is a circuit having a function of feeding back the current for driving. By constantly observing the current that drives this laser diode and confirming that the fluctuation rate of the drive current is within the specifications by comparing with the initial value, the light amount of the semiconductor laser described above is output normally. You can easily check whether or not.

Before the operator starts the measurement,
Ask the control particles to flow. If there is no abnormality in the particle detection optical system, the particle detection signal obtained by the particle detection unit has a certain distribution of signal intensity. If the distribution is not within the specifications, the optical path is made up of a semiconductor laser that is the detection light source, a collimator lens that makes the laser light from the semiconductor laser a parallel light flux, and a cylindrical lens that aggregates the laser light flux from the collimator lens. It can be found that an abnormality has occurred. Here, as described above, since the light amount of the semiconductor laser which is the particle detection light source is constantly observed, when this alarm is not generated, the collimator lens which makes the laser light from the semiconductor laser a parallel light flux, It can be found that an abnormality has occurred in the optical path formed by the cylindrical lens that aggregates the laser beams from the collimator lens.

As described above, when the sample solution containing the particle component is flown into the flow cell, and the particle detection optical system lit at a position upstream of the sample solution flowing in the flow cell detects particles passing through the flow cell. , The optical system that illuminates the imaging area in the flow cell is turned on, a still image of the particles detected by the imaging device is captured, and the particle analysis device that classifies the particles by analyzing the captured still image of the particles If the semiconductor laser, which is the power source for particle detection of the detection optical system, has a function of detecting an abnormality and a function of obtaining the distribution of the particle detection signal intensity, the following effects occur.

When there is an abnormality in the semiconductor laser that is the particle detection power source of the particle detection optical system, the current for driving the laser diode is constantly observed, so that the operator can be immediately notified of the abnormality.

Further, by allowing adjustment particles to flow before starting the measurement, a detection light source that emits laser light as detection light, a collimator lens, from the distribution of the particle detection signal intensity obtained at the particle detection unit, An abnormality in the optical path that guides the laser light to the upstream position of the flow cell can be detected by using a cylindrical lens or the like. Here, as described above, since the semiconductor laser that is the particle detection power source is constantly observed,
With a detection light source that emits laser light, a collimator lens, a cylindrical lens, etc., it is possible to detect whether there is an abnormality in the optical path that guides the laser light to a position upstream of the flow cell.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a particle analysis apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the overall structure of a particle analysis device.

The particle analysis apparatus comprises a flow cell 100 to which a sample liquid in which particles are suspended is supplied, and an image pickup means 10.
1, particle analysis means 102, and particle detection means 103.

The flow cell 100 flows a dyed urine sample, a blood sample, or the like very flatly with a sheath liquid (clean liquid containing no particles) as an outer layer. Flow cell 100
Has two inlets, one containing sample liquid and the other containing sheath liquid. A sample liquid supply means supplies a constant amount of sample liquid to the sample liquid inlet. A constant flow rate of sheath liquid is supplied to the sheath liquid inlet by the sheath liquid supply means. The sample liquid flow 110 is the image capturing means 10.
A laminar flow in which the sheath liquid encloses the sample liquid is formed in a direction that is extremely flat in the direction perpendicular to the optical axis 1 of 1 (microscope optical axis), and passes through the center of the flow cell 100 at a constant speed. The flow velocity of the sample liquid flow 110 is controlled according to the conditions set in the central control processing unit 29.

The image pickup means 101 has a function as a microscope, and includes a flash lamp 1 as a pulse light source, a flash lamp 1a for causing the flash lamp 1 to emit light, a field lens 2 for collimating a pulse light flux from the flash lamp 1, and a field. Microscope condenser lens 3 for focusing the parallel pulsed light flux 10 from the lens 2 on the sample liquid flow 110 in the flow cell 100.
The image of the image forming position 6 projected through the microscope objective lens 5 and the projection lens 7 which collects the pulsed light flux irradiated on the sample liquid flow 110 in 0 and forms the image at the image forming position 6 is captured by the interlace method It has a TV camera 8 for converting it into an image data signal which is a signal, a field stop 11 and an aperture stop 12 for limiting the width of the pulsed light flux. As the TV camera 8, a CCD camera or the like having a small afterimage is generally used.

The particle analysis means 102 converts the image data signal transferred from the TV camera 8 into a digital signal A.
An image memory 25 that stores data based on signals from the D converter 24 and the AD converter 24 at a predetermined address, an image processing control circuit 26 that controls writing and reading of data in the image memory 25, and an image memory 25 A feature extraction circuit 27 and an identification circuit 28 that perform image processing based on signals to classify and count the number of particles, a particle number analysis unit 40 that determines the number of particles in the sample solution, shooting conditions of the TV camera 8 and sample solution flow of the flow cell 100 Conditions, control of the image processing control circuit 26, storage of the image processing result from the identification circuit 28, exchange of data with the particle number analysis unit 40, and display unit 5.
It has a central control unit 29 for displaying 0.

The particle detecting means 103 includes a semiconductor laser 15 which is a detection light source for emitting a laser beam as a detection beam, a collimator lens 16 for converting the laser beam from the semiconductor laser 15 into a parallel laser beam 14, and a laser from the collimator lens 16. The cylindrical lens 17 that focuses only one direction of the light flux, the reflecting mirror 18 that reflects the light flux from the cylindrical lens 17, the laser condenser is provided between the microscope condenser lens 3 and the flow cell 100, and the laser light flux is sampled from the reflecting mirror 18. A micro-reflecting mirror 19 that guides to a close position on the upstream side of the image capturing area on the stream 110, a microscope objective lens 5 that collects the scattered light of the laser light flux by the particles, and reflects the scattered light that is collected by the microscope objective lens 5. The beam splitter 20 that causes the beam to be scattered and the scattered light from the beam splitter 20
1 includes a photodetector circuit 22 that receives light via 1 and outputs an electric signal based on its intensity, and a flash lamp lighting control circuit 23 that operates the flash lamp drive circuit 1a based on the electric signal from the photodetector circuit 22. The microscope objective lens 5 is also used as the image pickup means 101.

The basic operation of the particle analyzer will be described with reference to FIG.

The semiconductor laser 15 is caused to emit light when the measurement sample passes through the flow cell 100, and the particles in the sample are observed to pass through the detection region. The laser light flux from the semiconductor laser 15 is focused by the collimator lens 16 into the parallel laser light flux 14, and is focused by the cylindrical lens 17 in only one direction. This laser beam is reflected by the reflecting mirror 18 and the minute reflecting mirror 19 and the flow cell 1
The sample liquid flow 110 in 00 is irradiated. This irradiation position is a particle detection position where the laser beam is focused by the cylindrical lens 17, and is a position on the sample liquid flow 110 which is close to the upstream side of the particle static image capturing area.

When the particles to be measured cross the laser light flux, the laser light flux is scattered, and this scattered light is reflected by the beam splitter 20, received by the photodetector circuit 22, and converted into an electric signal. The particle detection signal is affected by the optical refractive index of the particle, absorption, size, the internal state of the particle, scattered light detection conditions, and the like.

Further, when the photodetection circuit 22 discriminates the detected electric signal from the detected electric signal of the particles to be image-processed, it is sent to the flash lamp lighting control circuit 23 and the particle number analyzing section 40. In the flash lamp lighting control circuit 23, the distance between the particle detection position and the image capturing area is set so that the flash lamp 1 emits light and images when particles reach a predetermined position in the particle still image capturing area of the TV camera 8. Then, after a predetermined delay time determined by the flow rate of the sample solution, the sample solution is sent to the flash lamp drive circuit 1a. The flash lamp lighting control circuit 23 sends a light emission ready signal at the same time as the detection signal, and controls the light emission timing of the flash lamp based on the timing of the interlace feel signal.

The particle analysis means 102 operates as follows. The image data signal output from the TV camera 8 is AD
The image data is converted into a digital signal by the converter 24 and the data based on the digital signal is controlled by the image processing control circuit 26.
5 is stored at a predetermined address. The data stored in the image memory 25 is read out by the image processing control circuit 26, input to the feature extraction circuit 27 and the identification circuit 28 for image processing, and the result is stored in the central control unit 29. To be done. What is stored is the particle classification result and the particle identification feature parameter data used for the particle classification. The particle classification and identification processing is automatically performed by a normal pattern recognition processing. Based on the image processing result and the measurement condition, and the image processed image information based on the particle detection signal from the central control unit 29, the photo detection circuit 22 and the control signal from the image processing control circuit 26, the final particle Summarize the image classification and identification results.

Next, a description will be given of the operation when an abnormality occurs in the particle detecting means 103 with reference to the flow charts of FIGS. 1 and 2.

Before starting the measurement, the measurement is carried out using the adjustment particles prepared in advance. The particle detection signal of the adjusting particles is obtained by the photodetection circuit 22, and the particle detection signal is sent to the particle number analysis unit 40. The particle number analysis unit 40 counts the number of particles and measures the particle detection signal intensity. Particle number analysis unit 40
It is determined whether the particle detection signal intensity distribution of the pseudo sample measured in step 2 is within specifications. If the particle detection signal intensity distribution is out of specifications, the operator is warned that the particle detection means 103 is abnormal. This time,
It is confirmed whether the light quantity of the semiconductor laser 15 is normally output. Generally, the semiconductor laser 15 is driven by an auto power control circuit (hereinafter referred to as an APC circuit). Since this APC circuit easily changes the light output of the laser diode due to fluctuations in the ambient temperature, the laser light is detected by the monitor light flowing through the photodiode so that a constant light output can be obtained even if the temperature changes. This is a circuit having a function of feeding back to the driving current. By comparing the current flowing through the laser diode with the initial value and confirming that the rate of change is within specifications, it is easy to confirm whether the light amount of the semiconductor laser 15 described above is normally output. I can. When it is confirmed that the light amount of the semiconductor laser 15 is normally output, the laser light from the semiconductor laser 15 is converted into a parallel laser beam 14
Between the collimator lens 16, the cylindrical lens 17 that focuses only one direction of the laser beam from the collimator lens 16, the reflecting mirror 18 that reflects the beam from the cylindrical lens 17, the microscope condenser lens 3, and the flow cell 100. A micro-reflecting mirror 19 for guiding a laser beam from a reflecting mirror 18 to a close position upstream of an image capturing area on a sample liquid flow 110; a microscope objective lens 5 for collecting scattered light of the laser beam by particles; Abnormality in the optical path formed by the beam splitter 20 that reflects the scattered light condensed by the objective lens 5, and the photodetector circuit 22 that receives the scattered light from the beam splitter 20 through the diaphragm 21 and outputs an electric signal based on the intensity thereof. Has occurred. With this, it is possible to find out which part of the particle detecting means 103 is abnormal at an early stage.

[0031]

According to the present invention, it is possible to find out which part of the particle detection system has an abnormality, so that the following advantages occur.

Before the measurement is started, the particles for adjustment are allowed to flow, and the function of taking the distribution of the particle detection signal intensity obtained in the particle detection section has a function of detecting a light source that emits laser light as detection light, With a meter lens, a cylindrical lens, etc., it is possible to detect an abnormality in the optical path that guides the laser light to a position upstream of the flow cell. Further, the laser light is guided to the upstream position of the flow cell by the detection light source that emits the laser light as the detection light, the collimator lens, the cylindrical lens, etc., because it has the function of constantly observing the drive current of the semiconductor laser that is the detection light source. It can detect which of the optical paths is abnormal. As a result, the operator can be promptly notified of the abnormality of the device.

[Brief description of drawings]

FIG. 1 is a block diagram of a particle analysis device.

FIG. 2 is a flowchart when an optical system for particle detection is abnormal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flash lamp, 8 ... TV camera, 22 ... Photodetection circuit, 40 ... Particle number analysis part, 100 ... Flow cell.

Claims (2)

[Claims] 1. When a sample liquid containing a particle component is caused to flow in a flow cell and an optical system for particle detection which is turned on at a position upstream of the sample liquid flowing in the flow cell detects particles passing through the flow cell. , The optical system that illuminates the imaging area in the flow cell with a certain delay is turned on, and a still image of the particle detected by the particle detection optical system is captured, and the captured particle still image is analyzed by the image analysis unit In the particle analysis device that classifies the above, the drive current of the semiconductor laser that is the light source for particle detection of the above-mentioned optical system for particle detection is constantly observed, and an abnormality in the light amount of the light source for particle detection is found by the change rate of the drive current. , A particle analysis device having control means for issuing a warning to an operator. 2. A measuring sample according to claim 1, wherein an adjustment sample is flown before the measurement is started, and the signal intensity of the particle detection signal obtained by the particle detection unit of the particle detection means is observed. If not satisfied, it is judged that there is an abnormality in the particle detection light source of the particle detection optical system, or that there is an abnormality in the optical path until the light flux of the particle detection light source reaches the particle detection unit, and the operator is warned. A particle analysis device having a control means for emitting the.