JPH0634675Y2 - Particle detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a particle detector for detecting particles by passing a liquid in which particles such as blood cells are suspended through fine pores.

[Prior Art] When measuring the number and size of particles such as blood cells, a sample in which the particles are suspended in an electrolytic solution is passed through the fine holes of the detector,
2. Description of the Related Art Particle counters that detect changes due to differences in electrical impedance between particles and liquids are widely used.

FIG. 5 is a schematic view of a main part of such a particle counting device. The cylindrical detector 46 is provided with fine holes 48, and the electrodes 50 and 52 are arranged inside and outside the detector 46, respectively. The detector 46 is immersed in a sample obtained by diluting blood or the like with an electrolytic solution, and an electric current is passed between the electrodes 50 and 52. A fixed amount of sample is sucked into the detector 46 through the fine holes 48 by the quantification device 64 connected to the pipe 54 inside the detector 46. Occurs at that time,
Electrical impedance between particles and liquid (eg electrical resistance)
An electrical change based on the difference between the two is detected by the detection circuit 62 connected to the electrodes 50 and 52, and the number and size of particles are measured. The inside of the detector 46 is cleaned by discharging the diluting liquid supplied from the diluting liquid tank 68 to the waste liquid tank 70. By the way, the hemoglobin concentration can also be measured with a sample for which white blood cell measurement will be described later. At that time, the pipe 56 communicating with the colorimetric measuring unit 66 is arranged outside the detector 46,
The hemoglobin amount is measured by deriving the sample 58 to the colorimetric measuring unit 66. A white blood cell measurement sample is prepared by diluting blood with a diluent about 250 to 500 times and then dropping a hemolytic agent to destroy red blood cells. The sample contains leukocyte particles and eluted hemoglobin.

The sample sucked into the detector 46 is generally collected in the pipe 54, but a part thereof is not collected and tends to settle inside the detector 46. As a result, the stagnant particles inside the detector 46 return to the vicinity of the micropores 48 again and generate a false signal similar to the particle signal even though it is not the particle to be measured, which causes a false count. Further, the staying sample may adhere to the internal electrode, and the internal electrode 50 may be easily soiled. Dirt on the electrodes causes noise.

To solve such a problem, Japanese Patent Laid-Open No. 61-159134 discloses that a suction pipe and a washing pipe are provided inside the particle detector, and a communication part is provided above the suction pipe to form a fine pore. It is disclosed that the sample liquid that has passed through is collected in a suction tube and that the liquid is convected from the upper communicating portion to the fine pores to prevent the particles from returning. In addition, by supplying the diluent from the washing pipe after the particle measurement and sucking it from the suction pipe,
Cleaning the interior of the detector is disclosed.

[Problems to be solved by the device]

In the above conventional example, it is necessary to provide a pore at the lower end of the detector, and the suction speed, counting time, so that the sample does not return to the vicinity of the pore again by convection,
Various restrictions were imposed on the implementation, such as the need to select the conditions of the convection capacity, the position of the suction tube, and the inner diameter.

It is an object of the present invention to provide a particle detector which is further improved in terms of eliminating the rebound of particles and the contamination of internal electrodes.

[Means for Solving the Problems]

In order to achieve the above object, the particle detector of the present invention comprises:
As shown in FIGS. 1 to 4, a tubular detector body 12 having electrodes on the outside, a pellet 14 having fine holes 16 attached to the lower portion of the detector body, and a detector body. A cleaning passage 32 for flowing a cleaning liquid and a sample passage for flowing a cleaning liquid, which is provided inside the micropore 12 and has one end communicating with the micropore in the vicinity of the micropore 16 and the other end communicating with the outside of the upper part of the detector body separately. It includes a passage 30 and an electrode 34 arranged in the washing passage 32.

[Action]

The detector body 12 is immersed in a sample in which particles are suspended in an electrolytic solution. An electrode provided outside the detector main body is used as an external electrode, an electrode 34 arranged in the cleaning passage 32 inside the detector is used as an internal electrode, and a current is passed between both electrodes. By sucking up the liquid from the sample passage 30 communicating with the fine holes 16, the particles pass through the fine holes 16 and the sample passage 30 inside the detector.
Inhaled into. When the particles pass through the micropores 16 and based on the difference in electrical impedance when the liquid passes, an electric signal is generated for each particle, and the number of particles is detected by measuring and measuring this particle signal. And size are measured.

When the cleaning liquid is supplied to the cleaning passage 32 and discharged from the sample passage 30, the sample inside the detector is washed away and washed.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, unless otherwise specified, the materials, shapes, relative positions, etc. of the constituent devices described in this embodiment are not intended to limit the scope of the present invention to them only, and are merely descriptions. It's just an example.

FIG. 1 is a side sectional view of an embodiment of the particle detector of the present invention, and FIG. 2 is a plan view thereof. The particle detector 10 is constructed by attaching a pellet 14 having fine holes 16 to a lower side surface of a cylindrical detector body 12. The detector body 12 is made of a material having good electrical insulation and excellent chemical resistance. ABS resin is one example. Detector body 12
A conductive coating 13 for imparting conductivity to the outer surface of the
For example, chrome-based plating treatment is applied. pellet
14 is screwed by pellet retainer 18, and detector main body 12
Is attached to. FIG. 3 is a partially enlarged sectional view of the pellet mounting portion. A lateral hole 20 and a stepped lateral hole 22 are provided on the side surface. The rubber sheet 24, the pellet 14, the rubber sheet 26, and the Teflon sheet 28 are inserted into the stepped hole A22, and are screwed by a pellet retainer 18 having a hole 19 with a gentle inclination in the center. Passages 30 and 32 are provided inside the detector body 12 so as to communicate with the lateral holes 20. The passage 30 is a sample passage for flowing the sample, and the passage 32 is the detector main body.
12 A cleaning passage through which a liquid for cleaning the inside flows. In the cleaning passage 32, a platinum electrode 34 serving as an internal electrode is arranged. On the other hand, the conductive film 13 covering the outer surface of the detector body 12 is grounded and used as an external electrode. Instead of the conductive coating, the external electrode may be provided as a conventional electrode outside the detector main body. At the top of the detector body 12, there is a mounting edge 23 and a mounting hole.
25 are provided. 17 is a ground line.

FIG. 4 is an example of a liquid circuit diagram for analyzing blood using the particle detector of the present invention. The electrodes are omitted in the drawing. The white blood cell measurement sample is prepared by diluting blood approximately 250 times with a diluting solution which is an electrolytic solution, and adding a hemolytic agent dropwise to hemolyze red blood cells. For the measurement of red blood cells and platelets, a diluted sample that is about 62500 times that of unlysed blood is used.
The particle detector 10 is immersed in the sample 36 in the container 38, and a constant current is passed from the inner electrode to the outer electrode. Since the external electrode is formed of the conductive film 13 by the film treatment as described above, it is not necessary to separately provide the external electrode, so that the influence of contamination (sample contamination) at the time of sample exchange is reduced.

The valve V ₁ opens and the syringe C ₁ performs the suction operation,
White blood cell particles in the sample 36 pass through the micropores 16. Since the horizontal holes 20 are provided in the same direction as the fine holes 16, the particles pass through the horizontal holes 20 without entering the cleaning passage 32, and the sample passage
Recovered to 30. Therefore, the internal electrodes arranged in the cleaning passage 32 are not contaminated by the sample,
Good detection sensitivity is guaranteed for a long period of time. Particles are fine pores
By passing through the micropores 16, the electric resistance in the micropores 16 changes, and a pulsed signal having a height corresponding to the size of the particles is generated between the electrodes. This particle signal is detected and measured by a detection circuit (not shown).

The sample reaches the flow cell 40 while counting particles. The amount of transmitted light of the sample reaching the flow cell 40 is measured by the light emitting element and the light receiving element (not shown). When the aspiration of the sample is completed, washing is performed. Valves V ₁ and V ₂ open, syringe C ₁
By performing the suction operation, the diluting liquid for washing is supplied from the diluting liquid tank 44 to the washing passage 32, and the sample in the sample passage 30 and the flow cell 40 is washed away to perform washing. Since the cleaning passage 32 communicates with the lateral hole 20 communicating with the fine hole 16 and the vicinity of the fine hole 16, the cleaning liquid from the cleaning passage 32 slightly circulates to the back side of the pellet, and the back side of the pellet 14 is also washed.
The area around the internal electrodes is also cleaned. By cleaning, contaminants such as dust and protein and air bubbles are removed. Therefore, the detection sensitivity does not deteriorate or become unstable. Especially, the sample passage 30, the washing passage 32, and the lateral hole 20.
By narrowing the inner diameter of (for example, around 1.5 mm), the flow rate of the cleaning liquid is increased, and the effect of removing contaminants and bubbles is enhanced. In that case, the electrode 34 also needs to be rod-shaped. The flow cell 40 is filled with the diluent, and the amount of transmitted light is measured. The amount of hemoglobin in the sample is measured by the amount of transmitted light of the sample and the diluent measured in the flow cell 40.

As described above, by connecting the flow cell 40 to the sample passage 30 of the particle detector 10 of the present invention, the hemoglobin concentration can be measured using the sample for counting. The flow cell 40 can be washed even better by opening the valve V ₃ and sucking the syringe C ₁ . Close valves V ₁ , V ₂ , V ₃ and open valve V ₄ ,
By causing the syringe C ₁ to perform the discharge operation, the waste liquid is discharged to the waste liquid tank 42. Z ₁ and Z ₂ are insulation chambers, and are for making the flow paths before and after the insulation chamber fluidly and electrically discontinuous. As a result, the influence of the nozzle or the like from the outside can be blocked.

[Effect of device]

Since the particle detector of the present invention is constructed as described above, it has the following effects.

Since the passage of the sample and the passage of the washing liquid are provided in the detector in the vicinity of the fine holes so as to communicate with each other,
The sample sucked into the detector all flows into the sample passage. Further, by flowing the cleaning liquid from the cleaning passage to the sample passage, the sample passage can be efficiently cleaned. This makes it possible to completely prevent the particles from returning. Further, since the internal electrodes are arranged in the cleaning passage in which the sample does not flow, there is no risk of being contaminated by the sample. Moreover, its configuration is simple, and there are few design restrictions, and it is easy to implement.

[Brief description of drawings]

1 is a vertical cross-sectional explanatory view showing an embodiment of the particle detector of the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a partially enlarged cross-sectional view of a pellet mounting portion in FIG. 1, and FIG. FIG. 5 is an explanatory diagram showing an example of a liquid circuit using the particle detector of the present invention, and FIG. 5 is a schematic explanatory diagram around a conventional particle detector. 10 …… Particle detector, 12 …… Detector body, 13 …… Conductive coating, 14 …… Pellet, 16 …… Micro hole, 17 …… Grounding line, 18 …… Pellet retainer, 19 …… Hole, 20 , 22 …… Horizontal hole,
24, 26 …… Rubber sheet, 28 …… Teflon sheet, 23 ……
Edge, 25 ... Mounting hole, 30 ... Sample passage, 32 ... Cleaning passage, 34 ... Electrode, 36 ... Sample, 38 ... Container, 40 ... Flow cell, 42 ... Waste liquid tank, 44 ...... dilution tank, V _1, V _2,
V ₃ , V ₄ …… Valve, C ₁ …… Syringe, Z ₁ , Z ₂ …… Insulation chamber, 46 …… Particle detector, 48 …… Micropore, 50,52 …… Electrode, 54,56 …… Pipe, 58 ... Sample, 60 ... Container, 62 ...
… Detection circuit, 64 …… Quantitative device, 66 …… Colorimetric measuring unit, 68…
… Dilution tank, 70 …… Waste tank

Claims (1)

[Scope of utility model registration request] 1. A tubular detector body having electrodes on the outside,
A pellet with fine holes attached to the lower part of the detector body is provided inside the detector body, and one end communicates with the fine hole in the vicinity of the fine hole and the other end is outside the upper part of the detector body separately. 1. A particle detector comprising: a washing passage through which a washing liquid flows, a sample passage through which a sample flows, and an electrode arranged in the washing passage.