JPH0628681Y2 - Abnormality detection device for particle detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an abnormality detection device for a particle detection device applied to a particle counting device or the like.

[Conventional technology]

In a particle counting device for counting particles such as blood cells, an electrode is provided in each of the chambers partitioned by a partition, and an electrolytic solution in which particles of blood prepared by diluting blood with a diluting solution are suspended is placed in both chambers. In addition, a particle detection device in which fine pores through which the particles pass is formed in the partition wall is widely used. By supplying a constant current between the electrodes and passing the electrolytic solution in which the particles are suspended in the micropores, and detecting an electrical change based on the difference in the electrical impedance of the electrolytic solution and the particles of the blood, the micropores are formed. The number of passed particles is counted.

By the way, when counting particles with this particle counter,
There is a problem that the fine holes are clogged, which increases the detection sensitivity and prevents normal measurement. The diameter of the micropores is, for example, several tens of μm when counting blood cells.
Since it is as small as 100 μm to 100 μm, it is particularly easy for the fine holes to be clogged.

Therefore, conventionally, there has been an abnormality detection device of the following particle detection device. That is, the first conventional example detects the time required for counting particles. When the clogging of the fine pores occurs, the fluid resistance of the fine pores increases and it becomes difficult for the electrolytic solution to flow. Therefore, the time required for a predetermined amount of electrolytic solution to flow through the fine pores increases. Therefore, paying attention to this, the time required for counting is detected and monitored.

In the second conventional example, there is one that detects the intervals and areas of particle signals obtained from the particle detection device. That is, when clogging occurs in the fine holes, the electrolyte solution becomes difficult to flow, and the intervals and widths of the particle signals to be detected are widened, and the detection sensitivity is also high, so the height of the particle signals is high. Therefore, paying attention to these, the intervals and areas of particle signals are detected and monitored.

[Problems to be solved by the device]

However, in the first conventional example, when the suction pressure for passing the electrolytic solution through the fine holes changes, the flow velocity flowing through the fine holes changes, so that the clogging detection sensitivity becomes low and erroneous detection occurs. There was a flaw.

The second conventional example has a drawback that the velocity of the particles flowing through the micropores changes depending on the concentration and size of the particles, so that the particles can be correctly detected only when measuring a certain particle having a certain density. In the case of blood, since the size and concentration of blood cells differ greatly from sample to sample, the detection sensitivity may be low or erroneous detection may occur depending on the sample.

Therefore, an object of the present invention is to provide an abnormality detecting device for a particle detecting device, which can stably detect clogging of fine holes without being affected by suction pressure, particle concentration and size. .

[Means for Solving the Problems]

The abnormality detection device of the particle detection device according to claim (1), wherein electrodes are provided in both chambers partitioned by partition walls, and fine holes are formed in the partition walls for containing the electrolytic solution in which the particles are suspended and for passing the particles. The particle detection device, a power supply for supplying a constant current between the electrodes, a voltage extracting means connected between the electrodes for extracting a DC component of a voltage appearing between the electrodes, and an output voltage of the voltage extracting means And a clogging detection unit that outputs a detection signal when the reference value exceeds the reference value, which is a reference for the clogging of the fine holes.

The abnormality detection device of the particle detection device of claim (2) is the claim (1)
In, the liquid temperature extraction means for detecting the liquid temperature of the electrolytic solution of the particle detection device and outputting an output voltage corresponding to the liquid temperature, and the output voltage of the voltage extraction means for the liquid temperature extraction means The output voltage of the correction means is compared with the reference value of the clogging detection means.

The abnormality detection device of the particle detection device according to claim (3) is defined by claim (1).
Alternatively, in claim (2), the voltage extracting means is provided with adjusting means for adjusting the displacement of the output voltage due to the variation in the hole size of the fine holes.

[Action]

According to the abnormality detection device of the particle detection device of claim (1), when a power supply is connected between the electrodes of the particle detection device, the DC component due to the impedance determined by the resistivity of the electrolytic solution and the hole size of the fine holes, and the particles are A voltage composed of a pulse component due to the increase of the impedance when passing through the fine holes appears between the electrodes. The DC component of this voltage is taken out by the voltage take-out means, and its level is compared with the reference value of the clogging detection means. In this case, when the opening area of the fine holes becomes smaller due to clogging, the impedance between the electrodes increases and the voltage between the electrodes rises, and when the voltage exceeds the reference value, the clogging detection means outputs a detection signal. As mentioned above,
Since the DC component of the voltage between the electrodes is due to the impedance determined by the resistivity of the electrolytic solution and the hole size of the fine holes, even if the suction pressure for passing the electrolytic solution through the fine holes changes as in the conventional example. The voltage between the electrodes does not change and is not affected by particle concentration or particle size. Therefore, it becomes possible to always stably detect the clogging of the fine holes.

According to the abnormality detection device of the particle detection device of claim (2), the voltage corresponding to the liquid temperature of the electrolytic solution is obtained by the liquid temperature extracting means, and the output voltage and the output voltage of the voltage extracting means are corrected by the correcting means. When the input voltage is output and the output voltage of the voltage extracting means is temperature-corrected, the corrected voltage is not affected by the impedance change due to the temperature of the electrolytic solution, and accurate clogging detection can be performed.

According to the abnormality detection device of the particle detection device of claim (3), by adjusting the displacement of the output voltage of the voltage extracting means due to the variation in the hole size of the fine holes by the adjusting means, it is possible to reduce the variation in the hole size of the fine holes. An unaffected output voltage is obtained,
It enables accurate clogging detection.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. That is, the abnormality detecting device of this particle detecting device includes a particle detecting device 1, a power source 2, and a voltage extracting means 3.
The liquid temperature extracting unit 4, the correcting unit 5, the clogging detecting unit 6, and the adjusting unit 18 are provided.

The particle detecting device 1 is provided with electrodes 11 and 12 in both chambers 9 and 10 partitioned by a partition wall 8 respectively, and a fine hole 7 for containing an electrolytic solution 13 in which particles are suspended and allowing the particles to pass therethrough.
Is formed on the partition wall 8.

The particle detecting device 1 includes a pellet 15 that constitutes the partition wall 8.
Particles such as blood cells are allowed to pass through the micropores 7 of FIG. 1 and the change due to the difference in electrical impedance between the particles and the electrolytic solution is detected. Nozzle 16 is provided to the fine hole 7 in
A diluted blood sample, which is an electrolytic solution, is discharged from 6 at a constant heavy rate, and the sheath liquid is caused to flow from the pipe 21 into the front chamber 9 at a constant pressure to flow around the nozzle 16 to form a sheath flow. There is. By forming the sheath flow in this way, the particles can pass through the center of the micropores 7 in line. In addition, the sheath liquid is made to flow from a pipe 17 connected to the other rear chamber (upper side in FIG. 1) 10 of both chambers 9 and 10 and is collected from a collecting pipe 14 provided in the rear chamber 10 to form the fine holes 7 The particles that have passed through are collected in the collecting pipe 14 and discharged. The front chamber 9 and the rear chamber 10 communicate with each other only through the fine holes 7 with the partition wall 8 containing the pellets 15 in between.

The electrode 11 is provided in the rear chamber 10 and a positive electrode is used as an example. The electrode 12 is provided inside the front chamber 9 and is made of stainless steel, and a negative electrode is used as an example. This electrode 1
The electrical resistance between 1 and 12 is determined by the resistivity or electrical conductivity of the electrolytic solution, the pore size of the fine pores, that is, the pore area and the pore length.

The power supply 2 supplies a constant current between the electrodes 11 and 12. In the embodiment, as shown in FIG. 2, a constant current source CC is connected to a DC voltage source CV ₁ of 100 V, and a constant current of about 0.2 mA is supplied between the electrodes 11 and 12. By supplying a constant current between the electrodes 11 and 12, a DC voltage determined by the electric resistance and the current value between the electrodes 11 and 12 is generated. Further, when particles such as blood pass through the fine holes 7, the electric resistance of the fine holes 7 apparently increases, so that the electric resistance between the electrodes 11 and 12 is large during the passage of the particles and the voltage generated between the electrodes 11 and 12 is large. Moreover, a voltage of a pulse component proportional to the size of the particles passing through the fine holes 7 is generated, this voltage is superimposed on the DC voltage, and these voltages appear between the electrodes 11 and 12. In this case, when dust or the like adheres to the fine holes 7 to reduce the effective area thereof, that is, when the fine holes 7 are clogged,
The impedance between the electrodes 11 and 12 increases and the fourth
As shown in the figure, the DC component E and the pulse component P of the voltage between the electrodes 11 and 12 in the normal state increase from the DC component E'and the pulse component P'when the clogging occurs, and the sensitivity increases. . As a result, noise may occur and the correct number of particles cannot be measured, or the correct size of particles cannot be measured.

The voltage extracting means 3 is connected between the electrodes 11 and 12 and extracts the DC component of the voltage V _D appearing between the electrodes 11 and 12. An embodiment of this voltage extracting means 3 is shown in FIG.
Sand, receiving an element of the voltage _{V D} between the electrodes 11 and 12 high input impedance and low output impedance for example a transistor _{T 1} of the emitter follower, by dividing the DC component in the resistor _R 1, _{R 2} of the voltage _{V D} , The pulse component is removed by the capacitor C. Further, the divided DC voltage is input to the non-inverting amplifier A ₁ and is adjusted to a predetermined value by the adjusting means 18 having a variable resistance as an embodiment, and the electrode 1
A voltage Vd proportional to the DC voltage between 1 and 12 is output. In the non-inverting amplifier A ₁ , R ₃ is a resistor and C ₁ is a capacitor.

The liquid temperature extracting means 4 detects the liquid temperature of the electrolytic solution 13 of the particle detecting device 1 and outputs an output voltage corresponding to the liquid temperature.
That is, since the electric conductivity or the resistivity of the electrolytic solution changes depending on the liquid temperature and the electric resistance also changes, the output voltage Vd of the voltage extracting means 3 when the liquid temperature is not constant.
Need to be temperature corrected. Therefore, the liquid temperature detecting means 22 of the liquid temperature extracting means 4 converts the liquid temperature of the electrolytic solution 13 into an electric signal and takes out an output voltage Vt proportional to the liquid temperature. As shown in FIG. 3, the liquid temperature detecting means 22 uses a thermistor having a resistance R _T as an example, and is embedded inside the electrode 12 made of stainless steel. When a constant voltage source CV ₂ of resistance R ₄ , 7.5V is connected to one end of the temperature detecting element 22, a voltage V _T is generated between the voltage detecting elements 22. This voltage V _T
Is applied to the non-inverting amplifier A ₂ , amplified by a factor of 2.5, and then input to the differential amplifier A ₃ . Differential amplifier A ₃
Then, for example, 2.5 V was subtracted by the constant voltage source CV ₃ and then amplified by 3.6 times to obtain the output voltage Vt which is in a proportional relationship with the liquid temperature T. In this embodiment, Vt
(Volt) = T (° C.) / 10. In the non-inverting amplifier A ₂ , R ₅ and R ₆ are resistors, C ₂ is a capacitor, and in the differential amplifier A ₃ , R _{7 to} R ₁₀ are resistors, and C ₃ is a capacitor.

The correction means 5 corrects the output voltage Vd of the voltage extraction means 3 with the output voltage Vt of the liquid temperature extraction means 4. The electrolyte has an electrical conductivity δ (T) or a resistivity ρ depending on the liquid temperature.
Since it has (T), the output voltage Vd obtained by the voltage extracting means 3 is also related to the liquid temperature and has the same characteristics as the output voltage Vt. Therefore, for example, in a pellet having a standard size of the micropores 7, the prefectural police can generally be established as Vd = Vt · f (Vt) + k. However, f (Vt) is Vt
, K is a constant. The functional expression can be obtained in advance by experiments. Therefore, based on this relational expression, Vd ′ = − Vt · f (Vt) + k ′ is assumed, and Vd ′ is calculated by substituting the actually measured voltage Vt into this equation, and further, the actually measured voltage Vd and the calculated voltage Vd ′.
By calculating (Vd + Vd ′) from the above, data unrelated to the liquid temperature can be obtained. This means that the correcting means 5 corrects the output voltage Vd of the voltage extracting means 3 using the output voltage Vt of the liquid temperature extracting means 4. As a result, the electrode 1 is independent of the liquid temperature.
It is possible to obtain a voltage corresponding to the voltage of the DC component between 1 and 12.

In such processing, for example, the output voltage Vd of the voltage extracting means 3 and the output voltage Vt of the liquid temperature extracting means 4 are input to an A / D converter (not shown) and converted into digital data, and both data are converted. Further processing device (not shown)
It suffices to input the data to and perform arithmetic processing, whereby data of the DC component irrelevant to the liquid temperature can be obtained.

More specifically, FIG. 5 shows the liquid temperature extracting means 4
The relationship between the output voltage Vt taken out by and the output voltage Vd taken out by the voltage take-out means 3 will be described. In the above relational expression between the output voltages Vt and Vd, it is assumed that the relationship of Vd = aVt ² + bVt + C (1) is established when the fine holes 7 are not clogged. However, a, b,
c is a constant. The curve shown by the solid line in FIG. 5 is obtained by sequentially measuring the voltages Vd and Vt while changing the liquid temperature using the pellet 15 having the standard size micropores 7. Based on this equation (1), assuming that the equation Vd ′ = − aVt ² + −bVt + C ′ (2), and adding the above equation (1) and this equation (2) to each other, Vd + Vd ′ = C + C It turns out that the data becomes irrelevant to the liquid temperature. That is, when the clogging does not occur, the measured voltage Vd
And the calculated voltage V obtained by substituting the measured voltage Vt into the equation (2).
d 'sum Vd + Vd of ^{the' = Vd-aVt 2 -bVt +} C '... (3) is C + C regardless liquid temperature' takes the value that will. For example 25
As shown in FIG. 5, when the output voltage Vt = 2.5 (Volt) and the output voltage Vd = Vd ′ = 3 (Volt), there is a relationship of C + C ′ = 6 (Volt). If clogging occurs, the voltage Vd + Vd 'becomes a value larger than C + C'.

In this way, it is possible to obtain a voltage that is not affected by the liquid temperature of the electrolytic solution 13, and it becomes easier to adjust the output voltage Vd and detect clogging.

The clogging detection means 6 uses the voltage Vd corrected by the correction means 5.
+ Vd 'is compared with a reference value serving as a reference for the clogging of the fine holes 7, and a detection signal is output when the value exceeds the reference value. For example, the reference value is a value (C +
A value of α = 0.15 is added to (C ′) as shown in FIG. 5 to obtain (C + C ′ + α), which is the clogging detection level. Then, Vd + Vd ′ = (Vd−aVt ² −bVt +) calculated using the data of the DC component obtained by the correction means 5, that is, the actually measured output voltages Vd and Vt.
C 'and), and the comparison determination by the comparison determination ^{unit, Vd-Vd' = Vd-} aVt 2 -bVt + C '<C +
When C '+ α is established, it is determined that no clogging has occurred. Further, Vd−Vd ′ = Vd−aVt ² −bVt + C ′ ≧ C +
When C ′ + α is satisfied, it is determined that a clogging has occurred,
It becomes possible to easily determine.

The output voltages Vd and Vt can be measured at any time during counting or other times.

The adjusting means 18 adjusts the displacement of the voltage due to variations in the hole size of the fine holes 7, that is, the size of the opening area. In the embodiment, the variable resistor of the non-inverting amplifier A ₁ shown in FIG. 2 is used. If the size of the fine holes 7 varies slightly for each pellet 15, the relationship between the output voltages Vd and Vt also varies to some extent. Therefore, if the above-described clogging is determined using the measured Vd and Vt, a problem occurs. Therefore, the output voltage Vd is adjusted to a predetermined value by the variable resistance town management means 18 shown in FIG. 2 so that the clogging can be correctly determined using the above-mentioned determination conditions. FIG. 6 shows the output voltages Vd and Vt.
, The curve Q ₁ shows the relationship when the output voltage Vd is not correctly adjusted, and the curve Q ₂ shows the relationship when the output voltage Vd is correctly adjusted. Also linear Q ₃ are 'indicates the level of the straight line Q ₄ are Vd + Vd when the output voltage Vd is correctly adjusted' correctly Vd + Vd when not adjusted it is indicative of the levels of. As is clear from this figure, it is possible to match the curve Q ₁ with the curve Q ₂ by matching the straight line Q ₃ with the straight line Q ₄ . Vd + Vd ′ = Vd−aVt ² −bVt + C ′ becomes (C +
Since the output voltage Vd may be adjusted so that it becomes C ′), the adjustment is very simple.

The abnormality detecting device of this particle detecting device extracts a value corresponding to the DC component of the voltage generated between the electrodes 11 and 12 by the voltage extracting means 3, and the value and the liquid temperature extracted by the liquid temperature extracting means 4 correspond to each other. Since the value corresponding to the direct current component of the voltage that does not depend on the liquid temperature can be obtained by performing the correction using the obtained value, the voltage extraction by the adjusting means 18 for absorbing the variation in the hole size of the fine holes 7 can be obtained. Means 3
Adjustment becomes easy, and the judgment of clogging detection becomes easy.

When the clogging of the fine holes 7 is detected under the condition that the liquid temperature and the fine holes 7 are constant, the liquid temperature extracting means, the correcting means and the adjusting means are unnecessary.

[Effect of device]

The abnormality detection device of the particle detection device of claim (1), since the direct current component of the voltage appearing between the electrodes is compared with a predetermined reference value,
Since the DC component of the voltage between the electrodes is based on the impedance determined by the electrolyte and the micropores, it is not affected by the flow velocity of the particles flowing through the micropores or the electrolyte, and the suction pressure, the concentration and size of the particles can be controlled as in the past. Since it is not affected, there is an effect that the clogging of the fine holes can always be detected stably.

Since the abnormality detection device of the particle detection device according to claim (2) temperature-corrects the output voltage of the voltage extracting means with a voltage corresponding to the liquid temperature of the electrolytic solution, it is possible to detect clogging accurately without being affected by the temperature of the electrolytic solution. become.

Since the abnormality detection device of the particle detection device according to claim (3) adjusts the displacement of the output voltage of the voltage extraction means due to the variation in the hole size of the fine holes, it is possible to detect clogging accurately without being affected by the hole size of the fine holes. become.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, FIG. 2 is a circuit diagram of voltage extracting means, FIG. 3 is a circuit diagram of liquid temperature extracting means,
FIG. 4 is a voltage characteristic diagram between electrodes when clogging occurs in the fine holes, FIG. 5 is a relationship diagram of the output voltages Vd and Vt, and FIG. 6 is a relationship diagram of the output voltages Vd and Vt in the variation of the fine holes. Is. 1 ... Particle detection device, 2 ... Power supply, 3 ... Voltage extraction means, 4 ... Clogging detection means, 7 ... Fine holes, 8 ... Partition walls, 9, 10 ... Both chambers, 11, 12 ... Electrodes, 13 ...
Electrolyte.

Claims (3)

[Scope of utility model registration request] 1. A particle detection device in which electrodes are provided in both chambers partitioned by partition walls, and fine holes are formed in the partition walls for containing an electrolytic solution in which particles are suspended and for allowing the particles to pass, and a fixed electrode between the electrodes. A power supply for supplying an electric current, a voltage extracting means connected between the electrodes for extracting a DC component of a voltage appearing between the electrodes, and a reference value serving as a reference for clogging of the fine holes with an output voltage of the voltage extracting means. An abnormality detection device for a particle detection device, comprising: a clogging detection unit that outputs a detection signal when the value exceeds the reference value. 2. A liquid temperature extracting means for detecting the liquid temperature of the electrolytic solution of the particle detecting device and outputting an output voltage corresponding to the liquid temperature, and the output voltage of the voltage extracting means for extracting the liquid temperature. An abnormality detection device for a particle detection device according to claim 1, further comprising a correction means for correcting the output voltage of the means, and comparing the output voltage of the correction means with the reference value of the clogging detection means. 3. The abnormality detection of the particle detecting device according to claim 1, wherein the voltage extracting means has an adjusting means for adjusting a displacement of the output voltage due to a variation in hole size of the fine holes. apparatus.