JP2676087B2 - Particle size distribution processor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for processing the particle size distribution of fine particles such as blood cells, cells and latex particles.

[Conventional technology]

The so-called particle size distribution chart, in which the size distribution of particles to be measured is obtained and expressed as an appearance frequency histogram with respect to the particle size, is used in various fields such as the industrial field.

In particular, an automatic particle analyzer that passes particles one by one through a minute detection unit and detects an electric signal (pulse) corresponding to the size of each particle obtained at that time is used to obtain extremely high values from the pulse height information. Since the particle size distribution diagram can be easily obtained, the field of application has been further expanded.

Also in the field of clinical testing, so-called sheath flow analyzers have come to be used, in which particles are precisely aligned in a line in the central part of the detection part and then measured, so that an extremely accurate particle size distribution map can be obtained. As a result, it has been actively applied to clinical diagnosis and the like by measuring the particle size distribution of red blood cells, white blood cells, and platelets in blood.

[Problems to be solved by the invention]

FIG. 3 is a diagram in which each particle in the measurement sample detected by the particle analyzer is classified into 128 levels according to the magnitude of the detection signal, and the frequency distribution thereof is displayed. The horizontal axis represents the size of the particles, and the vertical axis represents the frequency (the meanings of the horizontal axis and the vertical axis are the same in the particle size distribution charts below). Hereinafter, the number of classes of particle sizes in the particle size distribution chart, such as the 128 levels, will be referred to as the resolution of the particle size distribution. Usually, a resolution of about 50 to 200 is required to express the particle size distribution.

It is often the case that a frequency distribution chart such as that shown in FIG. 3 is temporarily stored in a storage device and then read as needed to confirm or analyze the particle size distribution. When storing, the frequency is accumulated in the memory of the storage device for each class of each size. In some cases, the particle size distribution of hundreds or thousands of samples may be stored. Therefore, the storage device needs to have a huge memory capacity. This means
Even when the storage device is built in the particle analysis device, or when it is provided in an external data processing device, the size and cost of the device are increased,
Not preferred.

The present invention reduces the memory capacity of the storage device by compressing and storing the particle size distribution data, and by restoring the particle size distribution from which the noise component has been removed from the original particle size distribution, as necessary, while reducing the memory capacity of the storage device. An object of the present invention is to provide a particle size distribution processing device capable of removing a noise component contained in the particle size distribution.

[Means for solving the problem]

In order to achieve the above object, the particle size distribution processing device of the present invention, as shown in FIG. 1, receives a particle detection signal sent from a particle detection means and a particle size distribution detection means 12 for detecting an original particle size distribution. , A particle size distribution compression means 14 for creating a compressed particle size distribution from which a noise component is removed from the original particle size distribution, a storage means 16 for storing the compressed particle size distribution, and a compressed particle size distribution read from the storage means to obtain the original particle size distribution. Particle size distribution restoring means 18 for restoring the particle size distribution from which the included noise components have been removed
It is configured to include and.

In the present invention, “compressed particle size distribution” refers to a particle size distribution obtained by compressing data by reducing the resolution of the original particle size distribution.

[Action]

The particle size distribution compression means 14 reduces the resolution of the original particle size distribution, compresses the data, and obtains a compressed particle size distribution from which noise components have been removed, so compared to a device that stores the original particle size distribution data as is. Thus, the storage memory capacity of the storage means 16 can be reduced.

Further, in the particle size distribution restored by the particle size distribution restoring means 18, the noise component contained in the original particle size distribution is removed.

〔Example〕

 Hereinafter, examples of the present invention will be described.

FIG. 1 shows a schematic configuration diagram of an example of the particle size distribution processing device 10 of the present invention. Upon receiving the particle detection signal A sent from the particle detection means 11, the particle size distribution detection means 12 detects the original particle size distribution B with a resolution of about 50 to 200. The particle size distribution compressing means 14 that has received the original particle size distribution B compresses the original particle size distribution B to a resolution of several to two or thirty, and creates a compressed particle size distribution C from which noise components have been removed. The compressed particle size distribution C is stored in the storage means 16
Is stored. After that, the compressed particle size distribution C is read from the storage unit 16 by the particle size distribution restoring unit 18, and the particle size distribution D from which the noise component included in the original particle size distribution is removed is restored.

The particle detection signal A received by the particle size distribution detecting means 12 is obtained by a known optical particle detecting means or electric particle detecting means. However, in order to obtain the particle detection signal that faithfully reflects the size of the particle, the electric particle detection means is preferable, and further, if it is the above-mentioned sheath flow method, it is most preferable.

Next, an example of the particle size distribution detecting means 12 will be described based on the schematic diagram shown in FIG. The particle detection signal A is input to the peak holder 20 and the peak detection circuit 22, and when the peak detection circuit 22 detects the peak of the particle detection signal, the peak holder 20 holds the peak value (peak value) of the particle detection signal. The peak value of the particle detection signal reflects the particle size information. The held peak value is converted to analog and digital in the A / D converter 24. A / D during A / D conversion
The BUSY signal is issued from the converter 24, and the peak detection and the hold of the peak value of the next particle detection signal coming very close are prohibited. The peak value converted into a digital value is input to the memory access controller 26. On the other hand, the memory 28 is provided with a number of storage areas corresponding to the resolution of the A / D converter 24. The memory access controller 26 operates the +1 adder 30 to add 1 to the content of the predetermined storage area in the memory 28 corresponding to the above digital value. The count control circuit 32 receives the count start / stop signal input from outside the main block, and controls the main particle size distribution detecting means 12 to operate for a predetermined time defined by the count start / stop signal. Therefore, the memory
In the 28, the number of particle detection signals of usually several thousands to tens of thousands obtained within the predetermined time is distributed to the storage area corresponding to the digital value and stored. After counting, memory 28
If the content of is displayed by a display means (not shown),
An original particle size distribution chart as shown in FIG. 3 is obtained.

As an example of the configuration of the particle size distribution detecting means 12, in addition to the one shown in FIG. 2, about 50 to 200 comparators corresponding to the resolution of the particle size distribution are arranged in parallel, and one of the comparators is Input a slightly different comparison voltage to the input terminal at a predetermined interval, input the particle detection signal to the other input terminal of each comparator, and input the number of particle detection signals that exceed the comparison voltage of each comparator. Is also known in which a counter is provided to count each comparator. In this case, a so-called cumulative particle size distribution can be obtained, and thus a conversion process is necessary when the particle size distribution as shown in FIG. 3 is required.

The particle size distribution compressing means 14 reduces the resolution of the original particle size distribution B to several to two or thirty, compresses the particle size distribution data, and removes noise components from the original particle size distribution. Specifically, the horizontal axis of the original particle size distribution (representing the size of particles) is divided into several to two or thirty segments, and the total number of particles (frequency) in each segment is calculated. By dividing each sum by the width of each segment,
The average value of the number of particles (frequency) in each segment is calculated, and the particle size distribution data is compressed. An example in which the original particle size distribution shown in FIG. 3 is compressed by the particle size distribution compressing means 14 is shown in FIG. The number of segments is 8. The bar graph in FIG. 4 is the compressed particle size distribution C obtained by removing the noise component from the original particle size distribution. Each bar is drawn at the center of the width of each segment. The dotted curve is the original particle size distribution. Also, the height of the peak of the compressed particle size distribution and the height of the peak of the original particle size distribution are made to match. Below, 6th, 8th, 10th, 12th,
Similarly in Fig. 14, the dotted curve shows the original particle size distribution B
And the bar graph represents the compressed particle size distribution C obtained by removing the noise component from the original particle size distribution.

The particle size distribution compression means 14 is composed of a known combination of logic circuit elements or a microprocessor.

The storage means 16 stores the compressed particle size distribution C. The frequency of each segment of the compressed particle size distribution is stored in the storage area in the storage unit 16 corresponding to each segment. Since only a few to a few thirty storage areas are used to store one compressed grain size distribution, the memory capacity can be much reduced compared to storing all the original grain size distributions.

The particle size distribution restoring means 18 reads the compressed particle size distribution C from the storage means 16 and restores the particle size distribution D from which the noise component included in the original particle size distribution is removed. An interpolation method is used to restore the particle size distribution having the same resolution as the original particle size distribution B from the compressed particle size distribution. Although various methods are known as the interpolation method, in the present embodiment, cubic spline interpolation (Kozo Ichida, Fuji City Yoshimoto, spline function and its application, Education Publishing, Tokyo, 1979, p. 43). -59.) Was used. The compressed particle size distribution C shown in FIG. 4 is interpolated using a cubic spline interpolation formula, and the restored particle size distribution D is shown in FIG. It was shown that the original particle size distribution B (FIG. 3) was substantially matched with the particle size distribution D restored.

The particle size distribution restoring means 18 is composed of a memory storing a cubic spline interpolation formula and a microprocessor.

Another example in which the particle size distribution is compressed and restored is shown below.

FIG. 6 is an example of a particle size distribution exhibiting bimodality, and the number of segments is 8 when the particle size distribution is compressed. FIG. 7 shows a particle size distribution D restored from the compressed particle size distribution C shown in FIG. The original particle size distribution B (Fig. 6) is considerably deformed and restored. The original particle size distribution B in FIG. 8 is the same as that in FIG. In FIG. 8, the number of segments when compressing the particle size distribution is 16. FIG. 9 shows a particle size distribution D restored from the compressed particle size distribution C shown in FIG.
The original particle size distribution B is well restored. Thus, as the original particle size distribution becomes more bimodal and complex, it becomes necessary to increase the number of segments.

FIG. 10 is an example of a particle size distribution that also shows bimodality, but since the particle size distribution may have noise, the particle size distribution is more complicated. In FIG. 10, the number of segments when compressing the particle size distribution is 8. In Fig. 11,
A particle size distribution D restored from the compressed particle size distribution C shown in FIG. 10 is shown. The original particle size distribution B (Fig. 10) has been considerably deformed and restored. The original particle size distribution B in FIG. 12 is the same as that in FIG. In FIG. 12, the number of segments when compressing the particle size distribution is 16. FIG. 13 shows a particle size distribution D restored from the compressed particle size distribution C shown in FIG.
The original particle size distribution B is better restored than in the case of FIG. The original particle size distribution B in FIG. 14 is the same as that in FIG. In FIG. 14, the number of segments when compressing the particle size distribution is 32. FIG. 15 shows a particle size distribution D restored from the compressed particle size distribution C shown in FIG. In FIG. 15, since the unnecessary noise component on the original particle size distribution B is also restored, the particle size distribution is distorted.
Therefore, in general, it can be said that the larger the number of segments when compressing the particle size distribution, the better the original raw particle size distribution can be restored, but if there is noise in the original raw particle size distribution, Increasing the number of segments is not always effective. Further, increasing the number of segments increases the required storage area of the storage means 16. In consideration of the above points, the number of segments is set to a suitable number between a few and a few.

Further, as an effect derived from the above-mentioned point, it is possible to remove the noise component and the like on the original particle size distribution by compressing and restoring the original particle size distribution. In the analysis of particle size distribution, various parameters such as average particle size and width of particle size distribution are calculated, and when multiple distributions overlap each other, decomposition processing into individual distributions is performed. When the particle size distribution analysis is performed, if the original particle size distribution has noise, an incorrect analysis result may be output. Therefore, in some cases, it is desirable to subject the particle size distribution from which the noise component has been removed to the analysis target by performing compression and restoration processing of the particle size distribution. In addition, first, the particle size distribution analysis is performed using the original raw particle size distribution as the analysis target, then the particle size distribution is compressed, and the particle size distribution analysis result (first analysis result) and the compressed particle size distribution are stored. After that, the particle size distribution obtained by removing the noise component from the compressed particle size distribution is restored, and the particle size distribution analysis is performed again with the restored particle size distribution as the analysis target (the result is the second analysis result). It is also useful to compare the analysis results of 2. By comparing these analysis results, it is possible to notify as an alarm that the particle size distribution has not been accurately restored or that the original particle size distribution contains a noise component.

FIG. 16 shows an example of the apparatus configuration in that case. Original particle size distribution B
Is analyzed by the particle size distribution analysis means 34a, and the analysis result is stored in the analysis result storage means 36 as the first analysis result. On the other hand, the restored particle size distribution D is the particle size distribution analysis means.
It is analyzed in 34b and becomes the second analysis result. The second analysis result and the first analysis result stored in the analysis result storage means 36 are sent to the analysis result comparison means 38, and if an abnormality is recognized, the warning means 40 gives an alarm. The particle size distribution analysis means 34a and 34b may be the same.

〔The invention's effect〕

According to the particle size distribution processing apparatus of the present invention, it is possible to compress and store the particle size distribution data and restore the original particle size distribution as needed, and to store the original particle size distribution data as it is. In comparison, the memory capacity of the storage device can be reduced.

In addition, by compressing and restoring the original particle size distribution, it is possible to remove noise components and the like that were in the original particle size distribution.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a particle size distribution processing device of the present invention, FIG. 2 is a schematic diagram showing an example of a particle size distribution detecting means, and FIG. 3 is a diagram showing an example of an original particle size distribution. 4, 6,
Figures 8, 10, 12, and 14 show the original particle size distribution and compressed particle size distribution, Figures 5, 7, 9, 11, 13, and 15 show the restored particle size distribution, and Figure 16 shows the present invention. It is a figure which shows another Example of this particle size distribution processing apparatus. 10 …… Particle size distribution processing device, 11 …… Particle detection means, 12 ……
Particle size distribution detecting means, 14 ... Particle size distribution compressing means, 16 ... Storage means, 18 ... Particle size distribution restoring means, 20 ... Peak holder, 22 ... Peak detecting circuit, 24 ... A / D converter, 26
...... Memory access controller, 28 ...... Memory, 30 ...
... + 1 adder, 32 ... Calculation control circuit, 34a, 34b ... Particle size distribution analysis means, 36 ... Analysis result storage means, 38 ... Analysis result storage means, 40 ... Alarm means

Claims (1)

(57) [Claims] 1. A particle size distribution detecting means for receiving a particle detection signal sent from a particle detecting means to detect an original particle size distribution, and a particle size distribution compressing means for creating a compressed particle size distribution by removing noise components from the original particle size distribution. A storage means for storing the compressed particle size distribution and a particle size distribution restoring means for reading the compressed particle size distribution from the storage means and restoring the particle size distribution from which the noise component contained in the original particle size distribution is removed. Characteristic particle size distribution processing device.