JPS61159134A - Particle detecting device - Google Patents

Abstract

PURPOSE:To perform the simple quantitative estimation of a sample right after being passed through the small detection hole of a detection pellet and to prevent an error in the plural-time detection of particles by providing a suction pipe at the upper side of the small detection hole of the detection pellet, and providing a cleaning pipe and connecting its upper end to a diluting liquid tank. CONSTITUTION:The detection pellet 2 which has the small hole for detection at the lower end is provided in a cylindrical detector 3 and a particle suspension is sucked through the small hole; and particles are detected on the basis of the difference in electric impedance between the suspension and particles when the particles pass through the small hole and converted into an electric signal by electrodes 4 and 5 provided inside and outside the detector 3. On the other hand, a suction pipe 6 is provided at the upper side of the small hole of the detection pellet 2 so that its lower end is positioned with a slight gap. A communication hole 7 is formed in the detector above the suction pipe 6 and a cleaning pipe 11 is provided in the detector so that its lower end is positioned nearby the detection pellet. The upper end of the cleaning pipe 11 is connected to the diluting liquid tank 8 through an on-off valve 10. Thus, diluting liquid is caused to flow to the suction pipe port and circulates to outside the suction pipe 6 through the communication hole 7.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention allows suspended fine particles such as blood cells suspended in a liquid to pass through pores, and detects and counts them based on the difference in electrical impedance between the liquid and the particles. The present invention relates to a particle extraction device, and more particularly to a particle extraction device that can accurately measure two or more types of fine particles of different sizes coexisting at the same time.

Conventional technology: Conventionally, when measuring particles such as blood cells, particles such as blood cells suspended in a liquid are passed through pores, detected based on the difference in electrical impedance between the liquid and the particles, and then detected using electrical A particle extraction device is used that converts into pulse signals and counts bus signals corresponding to particles.

When measuring particles of different sizes with this elegant conductive particle extraction device, pack sheath technology is used to wrap the sample flow to prevent it from spreading in order to prevent re-detection errors due to the formation of eddy currents immediately after passing through the pores. It was called JP-A-58-
119086, JP 58-160844, U.S. Pat. No. 4,258,058, U.S. Pat. No. 82993
Various techniques have been disclosed in Japanese Patent Publication No. 54, Japanese Patent Publication No. 5EA-26518, Japanese Patent Publication No. 22784-1984, and the like.

Problems to be Solved by the Invention In conventional particle extraction devices, unnecessary pulses are generated due to the return (engulfment) of the previous, previous, or current sample that has already been aspirated on the back side of the pore (inside the detector). A phenomenon occurred in which all signals were generated. In particular, this phenomenon
A mixture of large and small particles gets caught up in the detection area near the pore, and the pulse from the larger particle generates a pulse similar to when a small particle passes through the pore, e.g. red blood cells and platelets. This method has the disadvantage that large and small particles such as these are allowed to pass through the pores at the same time, resulting in large errors when performing classification and counting due to the difference in the size of the output pulse.

To prevent the above phenomenon, the back side of the detector pore should be
A method that uses a heavy structure to absorb all the particles that have passed through the pores, or a method that allows the flow of liquid containing particles to be wrapped in a liquid that does not contain particles and allows it to pass through all the pores, eliminating the phenomenon of entrainment. Although methods such as the above-mentioned pack sheath technology have been considered, the structure would be extremely complicated and there would be a drawback that it would be impossible to quantify the aspirated liquid.

Also, JP-A-58-119086, JP-A-58-1
The inventions described in Japanese Patent Publication No. 60844, US Pat. It is wrapped in a sheath around the entire center and allowed to flow to achieve its purpose.

Therefore, it is necessary to quantify the sample to determine the concentration of the sample before it passes through the pores.

That is, when quantification is performed after passing through the pores, the amount of the sample to be measured and the amount of the sheath liquid are mixed, so the amount of quantified liquid after passing through the pores and the amount of the sample to be measured do not correspond to l:l.

On the other hand, performing quantification before passing through the pores has the inconvenience of requiring disposal of residual liquid in the meter, which greatly affects the measurement cycle time. This is especially fatal for semi-automatic models in which the sample is placed in a container and the entire container is replaced.

The invention described in US Pat. No. 3,299,854 has a disadvantage in terms of sheath effectiveness because the sheath liquid tank is of an open-closed type, so that liquid cannot flow. The invention described in Japanese Patent Publication No. 58-26518 improves this drawback by adding a pump and a filter to generate flow. The invention described in Japanese Patent Publication No. 55-22784 is an invention for obtaining the same effect without using a pump and a filter.

The present invention has been developed in view of the above points, and it is possible to easily quantify a sample after passing through a pore without worrying about pulsating flow caused by a pump or replacing a filter, and to prevent errors in detecting particles multiple times. The object of the present invention is to provide a particle ejecting device.

Means for Solving the Problems The particle ejecting device of the present invention will be described using the numbers shown in the drawings. Next, the particle suspension liquid is sucked through the pore 1, and the particles are detected based on the difference in electrical impedance between the liquid and the particles when the particles pass through the pore 1. In a particle extraction device that converts into electrical signals using electrodes provided inside and outside, a suction tube 6 is provided above the detection pore l of the detection pellet 2 so that its lower end is positioned with a slight interval, A communication hole 7, a gap 30, and other communication parts are provided in the upper part of the suction tube 6 in the detector, and a cleaning tube 11 is provided in the detector so that its lower end is located near the detection pellet. It is characterized in that the upper end is connected to the diluent tank 8 via an on-off valve lO.

During action measurement, the sample flow passing through the pores 1 of the detection pellet 2 is very fast (5 m/sec or more), and this momentum generates a slow convection inside the detector in the direction of the arrow in the figure. This convection occurs because the pressure decreases because the flow velocity near the pore exit is high due to the relationship between flow velocity and pressure, and the particle-free liquid in the part of the pole 4 is sucked into the suction tube. This convection current flows so as to envelop the sample that has passed through the detection pellet 2, so that no rebound occurs. After each measurement, clean the inside of the detector to remove particles inside the detector. If this operation is not performed, particles in the convective liquid will generate a bounce signal. In addition, the suction speed, counting time, convection capacity (detector size), position and inner diameter of the suction tube must be determined to prevent the sample from returning to the back side of the detection pellet 2 due to convection during a single measurement. I see the need.

Actual/Unusual Examples Examples of the present invention will be described below based on the drawings. 1st
The figure shows an embodiment of the particle extraction device of the present invention, and FIG. 2 shows details around the detection pellet. This particle extraction device has a cylindrical detector (detection tube) 3 equipped with a detection pellet 2 having a detection pore 1 at the lower end. The particles are detected based on the difference in electrical impedance between the liquid and the particles when the particles pass through the pores 1, and the electrodes 4.
5 to convert it into an electrical signal.

Inside the blower 3, install a suction tube 6 that has the same central axis as the pore 1 and through which all the sample flow passing through the pore is sucked. Place them at a distance apart. This spacing and the inner diameter of the suction tube 6 are determined by the pore l.
The liquid flow after passing through is appropriately selected and determined so that it forms a laminar flow centered on the sample due to natural convection.

In the detector 8, a plurality of communication holes 7 for convection are bored in the upper part of the suction tube 6. Further, a cleaning pipe 11 having an opening near the detection pellet 2 and connected to an external diluent tank 8 via an on-off valve 10 is installed on the outside of the suction pipe 6 . The suction tube 6 is divided into a quantitative tube 12 and a branch tube 18 above and outside the detector 3, and the quantitative tube 12 has two light emitters 14, 15, and two light receivers 16, 17 separated by a predetermined internal volume. , are arranged so as to convert the presence or absence of liquid in the metered quantity f12 into an electrical signal. 18 is the sample beam force, 20 is the sample, 21 is the diluent (sheath liquid), 22 is the switching valve, 23 is the waste liquid pipe, 24 is the waste liquid tank, and 25 is the vacuum tube connected to the vacuum source. .

FIG. 2 is an enlarged view of the vicinity of the detection pellet 2 and the suction tube 6. The pore 1 has a diameter of 100 to 200 μm, the inner diameter of the opening at the lower end of the suction tube 6 is 1 to 2 μm, and the distance between the detection pellet surface and the opening at the lower end of the suction tube 6 is approximately 0.5 to 2 μm. A low-pressure part is formed near the suction tube mouth due to the change in flow rate caused by l, causing the diluted liquid outside the suction f6 to flow toward the suction tube mouth, and the flow passes through the communication hole 7 at the top of the suction tube and flows into the suction tube 6. It is arranged so that convection flows outward.

During measurement, the on-off valve 10 is closed, and the switching valve 22 is connected to the branch pipe 1811.
11 is closed so that the metering tube 12 and the waste liquid tube 23 are communicated with each other. The metering tube 12 has a circular cross section, and performs metering by photoelectrically converting the difference in lens action due to the presence or absence of a liquid using the opposing amounts of emitted and received light. When the quantitative measurement is completed, the on-off valve 10 opens, and the switching valve 22 operates to shut off the waste liquid pipe 23 from the set meal pipe 12 and communicate with the branch pipe 13, filling the inside of the detector 3 with diluent and detecting the liquid. The pore IJIF surface of pellet 2 is also cleaned.

3 and 4 show other embodiments of the invention. The particle side extraction device of this example has a center hole 2 at the bottom of the detector 3.
A cross-shaped spacer 27, a 7-shaped spacer 27, etc., is provided at a slight distance from the entire detection beret 2, and a suction pipe 6 such as a tube is connected to a short pipe portion 28 at the upper end of this spacer 27.
This has the advantage that the suction hole on the upper side of the detection pellet 2 can be easily positioned.

Also, instead of providing the communication hole 7 at the top of the suction pipe, the fifth
As shown in the figure, connect the suction tubes to the lower suction tube f6b and the upper suction tube 6.
It is also possible to separate the suction tubes into C and provide a gap 80 between both suction tubes, so that the liquid is caused to convect to the outside of the suction tube through this gap 30.

Next, an experimental example will be explained. Regarding the four patterns of piping (detector shapes) shown in FIGS. 6 to 9, the amount of return was investigated based on the number of PLTs (platelets). Figure 6 shows pattern 1 with no piping changes; Figure 7 shows pattern 2 with the pack sheath stopped; Figure 8 shows pattern 3 with the pack sheath stopped and the collection tube cut; This is a case where the pack sheath pressure is stopped and the natural convection tube 31 is provided. Each measurement was performed twice (total of 4 times) using two vials.

As a result of the experiment, approximately 1 ml of natural convection was generated in a counting time of 14 seconds. This is approximately (
This is the value calculated as */).

In addition, the measured values of the number of PLTs and the amount of return for each pattern are shown in the table below. The amount of return was based on the sheath flow being 0.

FIG. 1.theta. is a graph showing the amount of deflection for each discretization level. Furthermore, the particle sizes of RBC (red blood cells) and PLT ([111 platelets) in each pattern are shown in FIGS. 11 to 18. Figures 11 and 12 show the case of pattern 1 (sheath flow), Figures 13 and 14 show the case of pattern M<no pack sheath), and Figures 15 and 16 show the case of pattern 3. (No recovery pipe) is shown in all cases, and FIGS. 17 and 18 show the case of pattern 4 (natural convection).

The volume created by the outside of the suction tube and the inside wall of the detector is 8 m
1 or more, and particles do not diffuse into the sheath liquid,
A difference was observed between the case without communicating holes (pattern 2) and the case with communicating holes, as shown in the graph of FIG. 1θ, confirming the effect of the present invention on the object.

Effects of the Invention Since the present invention is configured as described above, it has the following effects.

(1) The structure is extremely simple.

(2) Relapse can be completely prevented, and in the case of blood cell measurements, the accuracy of platelet counting and platelet particle size measurement is improved.

(3) It is possible to easily exchange samples for each sample bead, and to accurately measure particles in suspensions containing particles of different sizes, such as in platelet and whole blood measurements.

(4) Since convection is generated inside the detector, sample quantification can be easily performed in the same way as conventional methods.

(5) Since no flow pump or filter is provided, troubles such as pump pulsation, filter clogging, and filter replacement do not occur.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram showing an example of a bucket of the particle extraction device of the present invention, FIG. 2 is an enlarged view of the area around the detection pellet in FIG. 1, and FIG. 3 is a 9j! of the pond of the present invention! 4 is a sectional view taken along the line A-A in FIG. 3, FIG. 5 is a sectional view showing still another embodiment of the present invention, and FIGS. FIG. 410 is a graph showing the experimental results, and FIGS. 11 to 18 are particle size distribution charts of RBC (blush #) and PLT (platelets) in each pattern. l...Detection pore, 2...Detection pellet, 3...Detector, 4.5-"l [Apricot, 6.6a, 6b, 6C-'3
U lead pipe, 7... Communication hole, 8... Dilute solution tank, 1o
... Opening/closing valve, 11... Washing pipe, 12... Metering pipe,
13...Branch pipe, 14.15...Light emitter, 16.17
... Light receiver, 18 ... Sample beam force, 20 ... Sample, 21 ... Dilution liquid (sheath liquid), 22 ... Switching valve,
23... Waste liquid pipe, 24... Waste liquid tank, 25...
Vacuum tube, 26...center hole, 27...spacer, 2
8...Short tube part, 80...Gap, 31...Natural convection tube Application Person Toa Medical Electronics Co., Ltd. Figure Z Figure 4 Figure Figure 6 Figure 7 Figure q Figure 11 Figure 12 Figure 14-Figure 1 Figure

Claims (1)

[Claims] 1 A particle-suspended liquid is sucked into a cylindrical detector equipped with a detection pellet having a detection pore at the lower end through the pore, and the interaction between the liquid and the particles is observed as the particles pass through the pore. In a particle extraction device that detects particles based on the difference in electrical impedance and converts it into an electrical signal using electrodes installed inside and outside the detector, the lower end of the detection pellet has a small gap above the detection pore of the detection pellet. A suction tube is provided so that the suction tube is located in the vicinity of the detection pellet, a communication part is provided in the upper part of the suction tube in the detector, and a cleaning tube is provided in the detector so that the lower end is located near the detection pellet, and this cleaning tube A particle detection device characterized in that the upper end of the device is connected to a diluent tank via an on-off valve.