JPS6252254B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspended particle detection device that can detect particles such as blood cells suspended in a suspension with high accuracy.

[Conventional technology]

Conventionally, in devices that automatically analyze various parameters related to blood cells suspended in physiological saline, etc., when measuring the number of red blood cells, white blood cells, etc. in a unit volume, the amount of blood cell suspension is aspirated. It was necessary to accurately determine the number of blood cells and convert it to the number of blood cells in raw blood.
For this reason, in the past, (1) the mercury in the U-shaped tube was brought into an unbalanced state, and when the mercury returned to a balanced state, the sample was suctioned by the mercury's own weight;
A device that generates a counting start signal and a counting end signal by creating a switch effect by contacting mercury with electrodes installed at appropriate locations on the tube. A device is used that assumes that the number of blood cells is constant and converts it from the number of blood cells per unit time. However, the former method had drawbacks such as poor contact with the electrodes due to oxidation, etc., and mercury, which is a pollutant, must be handled with care. In addition to mercury, there are other light-shielding liquids that can be used for optical detection using air pressure equivalent to its own weight, but the surface of the liquid is physically unstable due to surface tension and other factors. However, it has drawbacks such as being easily affected by dirt on the surface and vibration of the device. On the other hand, in the latter method, if the fine pores of the detector become clogged or dirty,
The flow velocity was no longer constant, and it was necessary to increase accuracy by lining up multiple detectors or rely on other compensation methods, making it difficult to call it an accurate measurement method.

Furthermore, Japanese Patent Publication No. 38-21547 describes a fluid measuring device in which the measuring device is driven by changes in the volume of fluid communicated with a plunger during the measuring time, thereby aspirating a fixed amount of sample. has been done. In FIG. 5 of this publication, a flexible diaphragm or thin film 182 is used as a device for transmitting fluid pressure, and a mechanical switch 9 is used to start and stop counting.
8,100 is shown.

FIG. 6 of this publication also shows a device for transmitting fluid pressure in which the inlet of a tubular member 74 is closed by a plug 242 made of an elastic rubber-like material.

[Problem that the invention seeks to solve]

However, in the device shown in FIG. 5 of the above publication, due to deterioration of the diaphragm or thin film 182, the diaphragm or thin film 182 may stop moving even if it accurately follows a certain amount of movement of the plunger. There is a problem that sometimes quantitative errors occur. In addition, mechanical switches make it difficult to perform delicate quantification, and the reproducibility of quantification is poor.
There is also the problem of deterioration of the switch.

Furthermore, in the device shown in FIG. 6 of the above publication,
A problem with the shape of the plug 242 is that air leaks from the gap between the plug 242 and the rod 246, which tends to cause quantitative errors. If an attempt is made to minimize this gap, the movement of the rod 246 will not be smooth.

The present invention was made in view of the above points, and the driving force is transmitted in this order to gas, bellows, solid piston, and sample, and the sample sucked through the micropores can be accurately quantified, and suspended particles can be accurately quantified. An object of the present invention is to provide a suspended particle detection device that can detect particles with high precision and operate stably.

[Means and actions for solving problems]

The suspended particle detection device of the present invention will be described with reference to the drawings.
is installed such that the lower part of this detector is immersed in the particle suspension in the sample chamber 1, and the upper part of this detector 7 is connected to a vacuum source via a valve 12, so that the inside of the sample chamber 1 and the detection Particle detection electrode 1 inside the container 7
1 and 10 respectively, and on the other hand, a piston drive chamber 13 is arranged above the detector so as to be always filled with a relatively high viscosity liquid 16 such as oil,
A tubular metering section 22 equipped with optical position detection devices 20 and 21 is connected to the top of this piston drive chamber, and the upper end of this tubular metering section is switchably connected to a vacuum source and a positive pressure source via a switching valve 23. A bellows 14 that expands and contracts by the positive pressure source and vacuum source is fixed to the upper part of the piston drive chamber 13, and the bellows 14 is penetrated so that the upper part moves up and down inside the tubular metering part 22 and the lower part moves inside the detector 7. A rod-shaped piston 15 is fixed to the lower part of the bellows so as to move up and down, and a packing 17 is provided around the rod-shaped piston between the piston drive chamber 13 and the detector 7.

In the device of the present invention, the rod-shaped piston 15 is fixed by passing through the bellows 14, and the bellows 14 is contracted by the vacuum source 24, thereby driving the rod-shaped piston 15 and generating negative pressure in the detector 7. I'm letting you do it. Also, the optical position detection devices 20, 21
This creates the start/stop signal for counting. The liquid inside the detector 7 is O-ring packing 17
and the liquid (oil) 16 in the piston drive chamber 13
sealed by.

The present invention can solve the problems of the apparatus described in the above-mentioned publication by having the structure and production as described above.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1 and 2 show an embodiment of the suspended particle detection device of the present invention. 1 is a particle suspension;
For example, in a sample chamber for containing a suspension of blood cells, a suspension of blood cells 2 is introduced into the sample chamber 1 from a sample introduction port 4 via a valve 3, and a valve 6 is introduced from a sample discharge port 5. It is discharged through. Reference numeral 7 denotes a detector having a fine hole 8 at its lower part that is large enough to allow one blood cell to pass through. Blood cell detection electrodes 10 and 11 are provided inside and outside. These electrodes 10 and 11 have fine holes 8
Blood cells passing through the blood cell are detected based on the difference in impedance between the fluid and the blood cell. Further, the upper part of the detector 7 is connected via a valve 12 to a waste liquid chamber and a vacuum source (not shown). On the other hand, detector 7
A piston drive chamber 13 is arranged on the upper side. A rod-shaped piston 15 driven by a bellows 14 protrudes inside the detector 7, and a piston drive chamber 13 housing the bellows 14 is filled with a liquid 16 such as relatively high viscosity oil. In order to prevent this liquid 16 from flowing into the inside of the detector 7, an O-ring packing 17 is provided around the rod-shaped piston between the piston drive chamber 13 and the detector 7. This liquid 16 serves to eliminate quantitative errors. That is, when there is no liquid 16, air leaks into the detector 7 through the gap between the packing 17 and the piston 15, which tends to cause a quantitative error. This liquid 16 is replenished from a replenishment tank 19 connected to the piston drive chamber 13 via a communication hole 18. At the top of the piston drive chamber 13, an optical position detection device 20,
A tubular metering section 22 having a tube 21 is connected thereto, and gas pressure such as air pressure is introduced into the bellows 14 through the metering section 22 . That is, the upper end of the metering section 22 is connected to a vacuum source 24 and a positive pressure source 25 via a switching valve 23 so as to be switchable. The piston 15 passes through the bellows 14 to reach the metering portion 22, and is configured such that the upper end of the piston is detected by optical position detection devices 20 and 21. The piston 15 is fixed to the lower part of the bellows 14 by screwing or the like.

In the suspended particle detection apparatus configured as described above, first, the valve 3 is opened and the blood cell suspension 2, which is a liquid to be measured, is introduced into the sample chamber 1. Next, suction pressure from the vacuum source 24 is introduced into the bellows 14, the bellows 14 is contracted from the state shown in FIG. 1 to the state shown in FIG. 2, and the piston 15 is raised. When the upper end of the piston 15 passes the lower optical position sensing device 21, a start signal is generated, and when the upper end of the piston 15 passes the upper optical position sensing device 20, a stop signal is generated. . Various parameters related to blood cells are measured using a gate signal between the start signal and the stop signal, and are taken as measured values per predetermined volume. As the piston 15 rises, the volume of the piston 15 protruding into the inside of the detector 7 becomes smaller, and the blood cell suspension is introduced into the inside of the detector 7 through the fine holes 8 by the amount of the decrease in the piston volume. Note that after opening the valve 12 in the detector 7 in advance and aspirating the sample, the valve 12
Keep it closed. On the other hand, the piston drive chamber 13
Due to the volume change of the bellows 14 inside, the replenishment tank 19
The liquid automatically flows into the piston drive chamber 13 through the communication hole 18 and fills it. After the measurement has been completed, the sample is discharged from the sample discharge port 5 through the valve 6, and the valve 6 is kept closed. Then bellows 14
At the same time, the valve 12 is opened to drain excess liquid inside the detector 7 into a waste liquid chamber (not shown).
to be discharged. The bellows 14 is expanded by positive pressure to the state shown in FIG. 1, and the upper end of the piston 15 is positioned at the center of the lower optical position detection device 21, thereby completing preparations for starting the next measurement.

FIG. 3 shows an example in which the suspended particle detection device of the present invention is used in an automatic blood analyzer. 26 is a suction pipe for aspirating a blood sample, and is connected to the blood storage container 2.
A predetermined amount of blood 28 contained in 7 is aspirated. 3
0 is a liquid processing device, and blood is processed in this liquid processing device 3.
The sample is diluted approximately 50,000 times as a sample for red blood cell counting, and approximately 500 times as a sample for white blood cell counting, and diluted, stirred, and lysed by adding a hemolytic agent to destroy red blood cells so that only white blood cells remain. , pretreatment such as addition of reagents is performed. Reference numeral 31 denotes a suspended particle detection device of the present invention, which detects blood cells based on the difference in impedance from the blood cell suspension, and sends a signal to the next detection circuit 33 through a line 32. On the other hand, the signal from the quantitative unit of the suspended particle detection device 31 is sent to the gate signal generation circuit 35 through the line 34, and the gate signal is sent to the detection circuit 33 or the next signal processing circuit 36. Signal processing circuit 36
Based on the blood cell signal regulated by the gate signal, the number of red blood cells, white blood cells, platelets, or blood cell signals is proportional to the particle size. From the calculation results with the colorimetric measurement results, MCH (mean corpuscular hemoglobin content),
Parameters related to blood cells such as MCHC (mean corpuscular hemoglobin concentration) are processed as analysis results. In this way, just by aspirating blood, it is possible to automatically dilute blood, dispense reagents, and perform calculation measurements, eliminating the drawbacks of liquid metering units and achieving higher accuracy. Analysis can be performed.

〔Effect of the invention〕

Since the present invention is configured as described above, the driving force is transmitted to the gas, the bellows, the solid piston, and the sample in this order, and the sample sucked through the micropores is quantified. In this case, the liquid to be measured is quantified using a solid piston that does not change its shape, which is extremely effective in terms of reproducibility and accuracy. Since it absorbs unreasonable force applied to the detection hole due to mechanical fluctuations or clogging, stable operation can be achieved. Furthermore, the action of the liquid in the piston drive chamber has the effect of preventing leakage that would cause a quantitative error, and also preventing vibration of the bellows.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the suspended particle detection device of the present invention. Figure 1 is a cross-sectional view of the bellows in an extended state, and Figure 2 is a cross-sectional view of the bellows in a contracted state. The explanatory diagram, FIG. 3, is a systematic explanatory diagram of an automatic blood analyzer equipped with the suspended particle detection device of the present invention. 1...sample chamber, 2...blood cell suspension, 3...
...Valve, 4...Sample inlet, 5...Sample outlet, 6
...Valve, 7...Detector, 8...Minor hole, 10,1
DESCRIPTION OF SYMBOLS 1... Blood cell detection electrode, 12... Valve, 13... Piston drive chamber, 14... Bellows, 15...
... Rod-shaped piston, 16 ... Liquid, 17 ... Packing, 18 ... Communication hole, 19 ... Replenishment tank, 20,
21... Optical position detection device, 22... Quantification unit,
23...Switching valve, 24...Vacuum source, 25...Positive pressure source, 26...Suction pipe, 27...Blood storage container, 28...Blood, 30...Liquid processing device, 31
...Suspended particle detection device, 32...Railway, 33...
Detection circuit, 34...Line, 35...Signal generation circuit, 36...Signal processing circuit.

Claims (1)

[Claims] 1. A detector with micropores in its lower part is provided such that the lower part of the detector is immersed in the particle suspension in the sample chamber, the upper part of the detector is connected via a valve to a vacuum source, and the Particle detection electrodes are provided inside the sample chamber and inside the detector, while a piston-driven chamber is placed above the detector so as to be constantly filled with a liquid such as oil with relatively high viscosity.
A tubular metering section equipped with an optical position detection device is connected to the top of this piston drive chamber, and the upper end of this tubular metering section is connected to a vacuum source and a positive pressure source via a switching valve so that the piston drive chamber can be switched freely. A bellows that is expanded and contracted by the positive pressure source and vacuum source is fixed to the upper part of the inside, and a rod-shaped piston is inserted into the lower part of the bellows so that the upper part moves up and down inside the tubular metering section and the lower part moves up and down inside the detector. What is claimed is: 1. A suspended particle detection device, characterized in that the device is fixed and provided with packing around a rod-shaped piston between a piston drive chamber and a detector.