JPH0311724Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention allows particles such as blood cells and platelets suspended in a liquid to pass through micropores, and detects the electrical difference or optical difference between the particles and the particle suspension. A device that detects particles based on physical differences and measures the average particle volume. Specifically, it uses a complicated method and device that divides the integration result of a pulse equivalent to one particle by the number of particles, as in the past. The present invention relates to an average particle volume measuring device that can easily and continuously determine the average particle volume without any problems.

[Conventional technology]

Conventionally, the method used to determine the MCV (mean corpuscular volume) value was to obtain the HT (hematocrit) value using a centrifuge and then divide it by the red blood cell count obtained from a hemocytometer.

Further, Japanese Patent Publication No. 51-26826 describes a method and apparatus for determining the dividing particle size for dividing the total volume of a particle system into two parts.

[The problem that the idea attempts to solve]

However, the above-mentioned method of dividing the hematocrit value by the red blood cell count has the disadvantage that it is not only inefficient and cannot process a large number of samples, but also may report incorrect results due to sample mishandling. .

In order to overcome this drawback, the applicant has already developed a device that can measure red blood cells and at the same time determine the HT value and MCV value. This device utilizes the fact that the detection signal (pulse height) of a hemocytometer is proportional to the volume of the measured blood cells.The pulse height of all side blood cells is measured and the cumulative value is divided by the number of red blood cells. , is a device for determining MCV values. Although this device has excellent measurement ability and high measurement accuracy, it is complicated and cannot be miniaturized, making it impossible to incorporate it into a small hematology analyzer. Furthermore, it was not possible to measure the average particle volume continuously, and it was also impossible to measure changes in particle volume in an extremely short period of time. As a result of extensive research, the inventor of the present invention discovered that the MCV value can be easily measured by monitoring the counts at two disc levels of a hemocytometer.

Hereinafter, the measurement principle in the present invention will be explained based on FIG. 1. FIG. 1 shows the cumulative particle size distribution curve of particles such as blood cells expressed as a percentage regardless of the number of particles, and the horizontal axis indicates the threshold level corresponding to the height of the particle pulse.

In addition, the solid line curve in Figure 1 is a sample prepared by diluting the blood of a certain specimen with isotonic saline.
This is the red blood cell cumulative particle size distribution curve when measured with a hemocytometer, and the dotted line is the red blood cell cumulative particle size distribution curve when the same sample blood as above was diluted with hypotonic saline and the red blood cells were expanded. .

It is thought that the particle size of normal particles exhibits a distribution state close to a normal distribution, and therefore, the particle size near the center of the particle distribution, that is, near 50% of the particle density, is considered to be correlated with the average volume of the particles. .

The present invention was developed in view of the above points and based on the knowledge that the MCV value can be easily measured by monitoring the counts at two locations on the disc level of the hemocytometer. , by adjusting a combination of servo motors, potentiometers, etc. to always maintain a predetermined voltage level (for example, 50%), and configuring the output voltage of the potentiometer to correspond to the average particle volume. An object of the present invention is to provide an average particle volume measuring device that can easily and continuously measure the average particle volume with a low-cost device.

As described above, the present invention relates to a device for simply measuring the average volume of particles. The differences from the device described in Japanese Patent Publication No. 51-26826 mentioned above, for example in the case of measuring the median value, are as follows.
The median value in the above publication is also called a division value or division particle size, and means that the total volume of all particles larger than the median value is equal to the total volume of all particles smaller than the median value, and is the median value used in statistics. This is different from the above. On the other hand, although the term "median value" is not used in this specification, the expression "particle size of 50% of the particle density" corresponds thereto. However, this 50% granularity is exactly the same as the median value used in statistics.

Further, FIG. 3 of the above-mentioned publication shows the cumulative particle size distribution of the particle volume. In contrast, FIG. 1 of the present application shows the cumulative particle size distribution of the number of particles. That is, the subject matter of the present invention and the invention described in the above-mentioned publication are different. Therefore, as mentioned above, the meaning of the median value is also different.

Furthermore, in order to measure the median value in the above-mentioned publication, all individual particles must be converted into other quantities (charges, digital codes) that can be accumulated and are proportional to the size of the particles. However, in order to obtain the 50% particle size according to the present invention, it is only necessary to convert the number of particles to voltage. The purpose of the present invention is to simply measure the average volume of particles, and converting the pulse height proportional to the particle size into another quantity and accumulating it as in the above publication is not in accordance with the specification of the present application. As described on page 3 of the book, this is exactly the problem that this invention aims to solve.

The above publication also describes a device that converts an input voltage pulse into an amount of charge proportional to the amplitude of each voltage pulse, or an analog converter. A digital converter or the like is required, making the device structure complicated or expensive. In contrast, the present invention only requires a frequency-voltage conversion circuit to convert the number of particles into voltage. Therefore, the device structure becomes very simple.

[Means to solve the problem]

In order to achieve the above object, the average particle volume measuring device of the present invention, as shown in Figure 2, passes particles suspended in a liquid through micropores, and generates an electric current between the particles and a particle suspension. a particle detection device 1 that detects particles based on physical or optical differences and generates a signal proportional to the particle size; 1 threshold circuit 2, a second threshold circuit 3 which is connected to this particle detection device and a reference voltage generation circuit 10 (described later) via a potentiometer 9 and has a predetermined threshold level, and the former first threshold circuit 2. The first frequency that converts the particle signal into voltage
a voltage conversion circuit 4; a divider 6 connected to the first frequency/voltage conversion circuit 4 and distributing the voltage from the conversion circuit 4 to a predetermined voltage level;
a second frequency/voltage conversion circuit 5 that converts the particle signal that has passed through the threshold circuit 3 into a voltage; a control circuit 7 connected to the second frequency/voltage conversion circuit 5 and the distributor 6; a servo motor 8 connected to the servo motor 8; a reference voltage generation circuit 10 connected to the servo motor via the potentiometer 9; and a recording device 12 connected to the potentiometer 9 via a conversion circuit 11. It is characterized by including the following.

[Effect]

A pulse signal proportional to the size of particles such as blood cells is sent from the particle detection device 1 to two threshold circuits 2 and 3. The first threshold circuit 2 is 100 in FIG.
%, it removes noise below the threshold voltage level and pulse signals caused by unnecessary small particles, and the particle signal that has passed through the first threshold circuit 2 is processed by the next first frequency·
The voltage is sent to a voltage conversion circuit 4, which generates a voltage corresponding to the number of particles per unit time. On the other hand, the potentiometer 9 is moved by the servo motor 8 so that the input signal from the control circuit 7 of the servo motor 8 becomes zero, and the voltage detected by the potentiometer 9 from the reference voltage generation circuit 10 at that time is By reading, for example, the threshold voltage corresponding to 50% in FIG. 1 can be read. By adjusting this voltage using the conversion circuit 11 to match the scale of the recording device 12, the continuous average particle volume can be measured and recorded.

〔Example〕

Hereinafter, the configuration of the present invention will be explained based on embodiments shown in the drawings. FIG. 2 shows an embodiment of the average particle volume measuring device of the present invention. The average particle volume measuring device of the present invention allows particles suspended in a liquid to pass through micropores, detects the particles based on electrical or optical differences between the particles and the particle suspension, and detects the particle size. a first threshold circuit 2 that is connected in parallel to this particle detection device 1 and has a threshold level that allows all particle signals to pass; a second threshold circuit 3 connected to the reference voltage generation circuit 10 via a potentiometer 9 and having a predetermined threshold level; and a first frequency/voltage that converts the particle signal that has passed through the former first threshold circuit 2 into a voltage. A conversion circuit 4, a divider 6 connected to the first frequency/voltage conversion circuit 4 and distributing the voltage from the conversion circuit 4 to a predetermined voltage level, and a second threshold circuit 3 of the latter.
a second frequency/voltage conversion circuit 5 that converts the particle signal passed through the circuit into a voltage, a control circuit 7 connected to the second frequency/voltage conversion circuit 5 and the distributor 6, and a control circuit 7 connected to the control circuit 7. a servo motor 8, a reference voltage generation circuit 10 connected to the servo motor 8 via the potentiometer 9, and a conversion circuit 11 connected to the potentiometer 9.
The potentiometer 9 is moved by the servo motor 8 so that the input signal from the control circuit 7 becomes zero.
It is configured to convert the voltage detected by the potentiometer 9 from the reference voltage generation circuit 10 at that time to match the scale of the recording device 12 and record it. 13 is a reference voltage generation circuit connected to the first threshold circuit 2.

In the device configured as described above, a pulse signal proportional to the size of particles such as blood cells is sent from the particle detection device 1 to two threshold circuits 2 and 3. The first threshold circuit 2 is for passing particle signals corresponding to 100% in FIG. 1, and removes noise below the threshold voltage level of the reference voltage generation circuit 13 and pulse signals caused by unnecessary small particles. The particle signal that has passed through the first threshold circuit 2 is sent to the next first frequency/voltage conversion circuit 4, which generates a voltage corresponding to the number of particles per unit time. On the other hand, the potentiometer 9 is moved by the servo motor 8 so that the input signal from the control circuit 7 of the servo motor 8 becomes zero, and the voltage detected by the potentiometer 9 from the reference voltage generation circuit 10 at that time is For example, by reading 50 in Figure 1,
% of the threshold voltage can be read. By adjusting this voltage using the conversion circuit 11 to match the scale of the recording device 12, the continuous average particle volume can be measured and recorded. As described above, according to the device of the present invention, the measurement result is not output after a predetermined time, but it is possible to obtain an output that matches the time, that is, in real time. Continuous recording by the device of the present invention is extremely effective in clinical blood tests such as testing the strength of blood cell membranes and reactions to various drugs. In particular, the volume of red blood cells in blood removed from the body changes even when diluted in physiological saline, and the degree of change is related to red blood cell permeability resistance. Can detect changes.

The device of the present invention can be applied not only to red blood cells and platelets, but also to particles other than blood cells suspended in a liquid, such as plankton or polyethylene latex in the industrial field.

[Effect of idea]

As mentioned above, the present invention is configured to calculate the average particle volume in gross terms, rather than integrating the volume of each pulse and dividing it by the number of particles, so the circuit that performs calculations such as multiplication It is extremely simple, miniaturized, and can be produced at low cost without the need of This has the effect that even short-term volume changes can be clearly captured.

[Brief explanation of drawings]

FIG. 1 is a curve diagram in which the cumulative particle size distribution curve of particles such as blood cells is expressed as a percentage regardless of the number of particles, and FIG. 2 is a systematic explanatory diagram showing one embodiment of the apparatus of the present invention. 1... Particle detection device, 2... First threshold circuit, 3
...Second threshold circuit, 4...First frequency/voltage conversion circuit, 5...Second frequency/voltage conversion circuit, 6...
Distributor, 7... Control circuit, 8... Servo motor,
9... Potentiometer, 10... Reference voltage generation circuit, 11... Conversion circuit, 12... Recording device, 1
3...Reference voltage generation circuit.

Claims (1)

[Scope of utility model registration request] Particle detection involves passing particles suspended in a liquid through micropores and detecting the particles based on electrical or optical differences between the particles and the particle suspension, producing a signal proportional to the particle size. A device 1, a first threshold circuit 2 connected to this particle detection device and having a threshold level that allows all particle signals to pass, and a potentiometer 9 connected to this particle detection device and a reference voltage generation circuit 10 described later. a second threshold circuit 3 having a predetermined threshold level; and a first threshold circuit 3 that converts the particle signal passed through the former first threshold circuit 2 into a voltage.
The voltage passed through the frequency/voltage conversion circuit 4, the divider 6 connected to the first frequency/voltage conversion circuit 4 and distributing the voltage from the conversion circuit 4 to a predetermined voltage level, and the second threshold circuit 3 of the latter. A second frequency/voltage conversion circuit 5 that converts a particle signal into voltage, a control circuit 7 connected to this second frequency/voltage conversion circuit 5 and the distributor 6, and a servo motor 8 connected to this control circuit. , the reference voltage generation circuit 10 connected to the servo motor via the potentiometer 9, and a recording device 12 connected to the potentiometer 9 via a conversion circuit 11. Average particle volume measuring device.