JPH0622204Y2 - Particle detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a particle detector applied to a particle analyzer or the like.

[Conventional technology]

In a conventional particle detector that detects a particle in a sample by immersing a pair of electrodes in a sample of an electrolyte solution in which particles are suspended, a high-frequency current is passed between the electrodes. There are a high-frequency current and a direct current at the same time, and a direct current.

Examples include Japanese Utility Model Publication No. 45-30950, Japanese Patent Application Laid-Open No. 60-82942, and Japanese Utility Model Publication No. 51-112393. Of these, the former two are such that the distance between the electrodes is reduced and a sample of an electrolyte solution in which particles are suspended is allowed to flow in the gap. However, in the former two particle detectors that bring the electrodes close to each other, the volume of the gap needs to be small enough to detect particles, so that the current density on the electrode surface becomes very high. As a result, there is a problem that a slight change due to dirt on the electrode surface easily affects the current, and the stability of particle detection sensitivity is poor.

On the other hand, the latter latter is one in which electrodes are provided in the sample of the electrolyte solution inside and outside the electrically insulating tubular container having fine pores. A specific example is shown in FIG. That is, this particle detector is an explanatory view when a high frequency current and a direct current are simultaneously applied to a particle detector for a direct current and used. In the figure, 100 is a tubular container of a particle detector, and 101 is a fine hole. The electrodes 102 and 103 are arranged so as to be immersed in the sample 104 of the electrolyte solution inside and outside the tubular container 100. 105 and 106 are electrodes 10
A power source for supplying a high-frequency current and a direct current through 2 and 103, respectively, and 107 is a fluid circuit for flowing the sample 104 together with particles suspended in the liquid through the fine holes 101. The detection circuit 108 detects changes in the high frequency current and the direct current generated when the particles pass through the fine holes 101 to detect the particles.

The detection sensitivity of this particle detector changes when the fine holes 101 become dirty.

Therefore, conventionally, a cleaning pipe for cleaning the fine holes 101 is provided.

For example, in (a) Japanese Patent Laid-Open No. 58-129349, a pipe for removing clogging is arranged with the nozzle facing the pores, and the suction force or the discharge force (air or liquid) is applied to the nozzle. Discharge)
To remove the clogging of the pores. (b) No. 61-34460 of Japanese Utility Model Publication No. 61-34460 discloses a nozzle for injecting a cleaning liquid toward pores.

Further, in (c) JP-A-61-159134, a suction pipe and a washing pipe are arranged toward the pores, and after the measurement, a diluent is supplied from the washing pipe and suction is performed from the suction pipe. It is described to clean the back side of the holes. However, (c) is intended to prevent the particles from returning to the first place, and is not intended to remove the clogging of the pores.

[Problems to be solved by the device]

In each of (a) to (c), since a pipe for cleaning is provided separately from the electrode, the structure is complicated and the cost is high.

Therefore, an object of the present invention is to provide a particle detector capable of cleaning fine holes with a simple structure.

[Means for Solving the Problems]

The particle detector of the present invention comprises a first container for containing a sample of an electrolyte solution in which particles are suspended, a second container in communication with the first container through fine holes, the first container and the second container.
And a pair of electrodes, each of which is provided in the inside of the container and at least one of which is formed by a cleaning pipe having a tip facing the fine hole.

[Action]

According to the configuration of the present invention, when a voltage is applied between the electrodes, a current flows through the micropores, and when particles pass through the micropores at that time, the detection signal appears between the electrodes, so that the particles can be detected. In this case, since at least one of the electrodes is formed of a cleaning pipe with its tip facing the fine hole, the fine hole can be washed by blowing a washing liquid from the electrode. Therefore, the micropores can be cleaned with a simple structure, and good detection sensitivity can be maintained.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. That is, this particle detector is used in the first container 1
And a second container 2 and a pair of electrodes 14 and 20.

The first container 1 and the second container 2 are a pair of containers that contain a sample 62 of an electrolyte solution in which particles are suspended, and they communicate with each other through micropores 11. The first container 1 and the second container 2 are made of a relatively transparent resinous material having a cavity for containing the sample 62 therein. As a material, polymethylpentene or the like, which is excellent in electrical insulation and chemical resistance and has a low dielectric constant, is suitable. The cavity of the first container 1 has an upper opening and a lower funnel shape, which is continuous with the nipple N ₄ . A lid 5 is sealed and fitted into the upper opening by an O-ring 6. The lid 5 has nipples N _{1 to} N ₃
Is installed. Further, a small hole 38 communicating with the second container 2 is formed in the lower side portion.

The second container 2 is a connecting part 3 for connecting to the first container 1.
2 is projected. A lateral hole 63 is provided inside the second container 2.
And the vertical hole 64 are provided so as to communicate with each other, and these form a cavity. An opening is formed on the side of the lateral hole 63 opposite to the first container 1, and a plug 22 is sealed by an O-ring 23 and fitted into this opening. First container 1 with lateral hole 63
The side is tapered, and a recess 13 for storing pellets having a step with a thread groove is provided at the tip thereof as shown in FIG. 2, and the tip of the recess 13 further comprises the first container 1
The small hole 13a communicating with the small hole 38 of FIG.

FIG. 2 is an enlarged sectional view of a portion of the fine hole 11. A disc-shaped pellet 12 made of ruby having a microscopic hole 11 with a diameter of about 100 μm in the center is sandwiched between seal packings 27 and 28 in a recess 13 and is pressed by a pellet presser 33 via a slide packing 29 to be attached. .
The seal packing 27, 28, the slide packing 29, and the pellet holder 33 are provided at their centers with small holes 13b aligned with the small holes 13a and of the same size as the small holes 13a. A threaded portion that engages with the threaded portion of the recess 13 is provided on the outer peripheral surface of the pellet presser 33, and an operating recess 21 is provided on the side surface so that the pellet presser 33 can be easily screwed. The slide packing 29 is for preventing the rubber seal packings 27 and 28 from rotating and being kinked when the pellet holder 33 is screwed, and a sheet made of Teflon (trade name) is used as an example. . The small holes 13a and 13b are channels for flowing the sample 62 of the electrolyte solution into the fine holes 11, and one end 61 thereof, that is, the hole end on the side surface side having the recess 21 of the pellet holder 33, allows the liquid to flow smoothly. It has a curved surface that extends outward. The lid 18 is sealed and fitted to the upper opening of the vertical hole 64 by an O-ring 19. The lid 18 is provided with a conical taper portion at the center on the inner surface side, and the nipple N ₆ penetrates through the center thereof. For this reason, the bubbles in the second container 2 easily flow out from the nipple N ₆ .

The pair of electrodes 14 and 20 are provided inside the first container 1 and the second container 2, respectively, and the electrode 20 is formed by a cleaning pipe whose tip faces the fine holes 11. The electrode 14 is attached to the lower side of the hollow portion of the first container 1 so as to penetrate from the outside into the hollow portion, taking the positive side as an example. The tip of the electrode 14 is sharp and reaches near the pellet 12 having the fine holes 11. The electrode 20 has a minus side as an example, and penetrates through the center of the stopper 22 of the second container 2 and is attached so that the tip thereof faces the pellet 12. Platinum or the like, which does not easily corrode, is suitable as a material for the electrodes 14 and 20. First container 1 and second container 2
Are connected to each other with a set screw 34 sandwiching the O-ring 31 at the protruding connecting portion 32. Therefore, a gap 35 is formed between the first container 1 and the second container 2 in a portion other than the connecting portion 32. Since the dielectric constant of the space (air) is small and the space between the first container 1 and the second container 2 is separated by the gap 35, the capacity of that portion is small. Therefore, the electrode 1
The high frequency current flowing between 4 and 20 is relatively large and the detection sensitivity is high. As in this example, the electrodes 14 and 20 are placed close to each other with the pellet 12 in between, and the electrode 1
By making the tip of 4 sharp, a high-frequency current can be concentrated and flown in the fine holes 11, so that the detection sensitivity is further improved. According to the experiment, the capacitance between the electrodes 14 and 20 is 10 pF, which is 1/10 or less of the conventional value. Further, even if the liquid amount of the sample 62 in the first container 1 changes to some extent, the capacity does not change because there is the gap 35 between the first container 1 and the second container 2, so that the high-frequency current is almost the same. The detection sensitivity is stable without being affected.

The third container 3 communicates with the nipple N ₄ and the nipple N ₄
Of the sample 62 onto which the sample 62 was dropped and the nipple N ₄
And an exhaust passage 36 communicating with the outside from the bottom of the insulating chamber 8. In the third container 3, the upper member 3a and the lower member 3b are connected with the O-ring 7 interposed therebetween, and the upper member 3a is connected to the O-ring 7.
A ring 4 is sandwiched and connected to the bottom of the first container 1.
The lower member 3b is formed with a taper-like portion at the center thereof, an outlet 37 is formed at the center thereof, and the outlet 37 is provided with a nipple N ₅ connected to the discharge flow path 36. The insulating chamber 8 is formed in the third container 3 so as to form a cavity having a relatively large volume. Therefore, the electrolyte sample 62 contained in the first container 1 is fluidly and electrically separated from the sample in the discharge channel 36 by the air layer in the insulating chamber 8. Therefore, the influence of instability factors such as electrical noise entering from the outside through the discharge passage 36 is eliminated. That is, the detection sensitivity is stable. If the insulating chamber 8 is not provided, the electrolyte sample 62 existing in the discharge flow channel 36 becomes an antenna and is easily affected by the external electrical influence. Further, if the discharge flow channel 36 is a tube, the influence is caused by the routing thereof. Since the degree of changes, it becomes extremely unstable.

FIG. 3 is a fluid circuit diagram of a measuring system using the particle detector of this embodiment, in which blood is diluted and a hemolytic reaction is performed to classify and count white blood cells using a sample for the measurement.

The heater 110 is for keeping the diluent and the hemolyzing agent at a constant temperature in order to stabilize the reaction of the measurement sample.
The metering valve 120 is for quantifying and collecting a fixed amount of blood in a circular slice. The quantification unit 130 quantifies the sample for measurement during counting.

The metering valve 120 is composed of two fixed elements 122 and 126 and a movable element 124 which is sandwiched between the fixed elements 122 and 126 and which is rotatable about a shaft 118. The blood 116 contained in the container due to the suction operation of the cylinder C ₁ causes the suction tube 117 and the passage P _1- .
It is quantified by filling the flow passage P _{2 in} order of P ₃ . On the other hand, when the valve V ₁ is switched and the cylinder C ₂ performs the discharging operation, the diluent having a constant temperature that has passed through the heater 110 is discharged into the reaction tank 128 through the passages P _{4 to} P ₆ and the inner wall thereof is washed. . Then, the valve V ₁ returns to its original state and the cylinder C ₂ performs a suction operation to suck a fixed amount of the diluting liquid from the diluting liquid tank 112.

A negative pressure pump 136 that generates a negative pressure (pressure lower than atmospheric pressure) is connected to the waste liquid tank 138. By opening the valve V ₃ , the sample 62 for measurement of the previous sample in the first container 1 is discharged from the nipple N ₅ through the nipple N ₄ and the insulating chamber 8 to the waste liquid tank 138 through the discharge passage 36. . Valve V ₃
And the valves V ₄ and V ₈ are opened, the diluent in the reaction tank 128 is introduced into the first container 1 from the nipple N ₁ by the negative pressure, and the inner wall thereof is washed. Then, the valve V ₄ is closed and the valve V ₃ is opened again, so that the diluent in the first container 1 is discharged from the nipple N ₅ .

Next, the movable element 124 of the metering valve 120 rotates and the passage P
₂ communicates with passages P ₄ and P ₆ . When the valve V ₁ is switched and the cylinder C ₂ performs the discharging operation, the blood quantified in the passage P ₂ is transferred to the reaction tank 128 together with the diluting liquid having a constant temperature. At the same time, the valve V ₂ is switched and the cylinder C is switched.
_The hemolyzing agent having a constant temperature passes through the heater 110 by the discharging operation of _{3 and} is also discharged into the reaction tank 128. Therefore, a predetermined amount of blood, a diluent, and a hemolytic agent are mixed and homogenized in the reaction tank 128 at a constant temperature to make a sample for measuring leukocytes in which erythrocytes are destroyed. Further, the valve V _{9 is} also switched and the cylinder C ₁ performs the suction operation, whereby the diluent is sucked from the diluent tank 112. After that, the movable element 124 of the metering valve 120 rotates and returns to the original state again. The valve V ₉ returns to the original state and the cylinder C ₁ performs the discharging operation, whereby the passages P ₃ , P ₁ and the suction tube 117 are released.
The blood that remains in the chamber is washed away with the diluent.
The white blood cell measurement sample is sent from the nipple N ₁ into the first container 1 by opening the valves V ₄ and V ₈ . Since the valve V ₃ is closed, almost no sample for measurement falls into the insulating chamber 8 and remains in the first container 1. Further, when the valves V ₅ and V ₇ are opened, the diluent is introduced into the second container 2 from the electrode 20 having the washing pipe while pushing up the sphere 132 of the quantification unit 130 and the valve V ₅ is introduced from the nipple N _6. It is discharged to the waste liquid tank 138 after passing through ₇ . At this time, since the cleaning pipe 20 reaches the vicinity of the pellet 12, the surface of the pellet 12 and the fine holes 11 can be cleaned.

Next, by opening only the valve V ₆ , the liquid in the second container 2 is discharged from the cleaning pipe 20, and the sample for measurement in the first container 1 becomes the fine holes 11 of the pellet 12. Pass through. At this time, an electric current is applied to the fine holes 11 and a particle signal is detected. The amount of the measurement sample passing through the fine holes 11 is quantified by the quantification unit 130. The quantification unit 130 includes a sphere 132, a glass tube 134 having an inner diameter that is slightly larger than the outer diameter of the sphere 132, and sensors S ₁ and S for detecting the sphere 132 attached at different positions outside the glass tube 134. ₂ and in this embodiment, the light emitting element D ₁ and the light receiving element D ₂ are opposed to each other to form the sensor S ₁ .
Similarly, the light emitting element D ₃ and the light receiving element D ₄ are opposed to each other to form a sensor S ₂ . Since the gap between the glass tube 134 and the sphere 132 is extremely small, the amount of the liquid leaking through the gap at the time of quantifying the sample for measurement can be immortal, and the sample for measurement corresponding to the volume between the sensors S ₁ and S ₂ can be immortalized. 62 is quantified. Electrode 14,
Cables 70 and 72 are respectively connected to 20, and a high frequency current of several tens of MHz is passed between both electrodes 14 and 20.
The cable 70 is connected to one end of a high frequency current source 140 and a high frequency signal detection circuit 142, and the cable 72 is connected to the other end of the high frequency current power supply 140 and a detection circuit 142 and grounded. By analyzing the signal detected by the detection circuit 142, the internal information of the white blood cell particles (for example, the size of the nucleus) can be obtained, and the white blood cells can be classified and counted. Moreover, the size information of white blood cell particles can be obtained by using a direct current source instead of the high frequency current source 140.
Alternatively, both can be used together.

By the way, if a nipple for intermittently supplying air from the outside is provided on the upper side surface of the insulating chamber 8, the measurement sample 62 in the first container 1 can be stirred. In the case of this agitation, the liquid in the insulating chamber 8 has an air tank, so the first container 1
It does not mix inside. That is, contamination (mutual contamination of liquids) does not occur.

In addition, 129 and 135 are orifices.

Further, in the above embodiment, the electrode 20 is a cleaning pipe,
The electrode 14 or the electrodes 14 and 20 may be used as a cleaning pipe. In addition, the above embodiment has a third container 3
As shown in the figure, the third container 3 may be omitted, that is, the discharge passage may not be connected or may be detachable.

[Effect of device]

In the particle detector of the present invention, at least one of the electrodes is formed by a cleaning pipe whose tip faces the fine hole, and therefore the fine hole can be washed by blowing a cleaning liquid from the electrode. Therefore, the micropores can be cleaned with a simple structure, good detection sensitivity can be maintained, the entire space can be reduced, and the cost can be reduced. In addition, since the electrodes can be arranged close to the fine holes, the current can be concentrated in the fine holes, and the detection sensitivity can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the fine holes thereof, FIG. 3 is a fluid circuit diagram of a measuring system using the particle detector of this embodiment, and FIG. [Fig. 4] is a schematic explanatory view of a conventional example. 1 ... First container, 2 ... Second container, 11 ... Micropores, 14,20 ... Electrode, 62 ... Sample

Claims (1)

[Scope of utility model registration request] 1. A first container for containing a sample of an electrolyte solution in which particles are suspended, a second container communicating with the first container by means of micropores, and a first container and a second container. A particle detector provided with a pair of electrodes, each of which is provided in the inside thereof and at least one of which is formed by a cleaning pipe whose tip faces the fine hole.