JPH0675711B2 - Microorganism measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a microorganism measuring device for continuously image-processing and measuring microorganisms.

[Conventional technology]

At the sewage treatment plant, air is blown into the inflow water (aeration) in the air ration tank to remove the organic matter by allowing the microorganisms to ingest the organic matter in the inflow water, and then the microorganisms are allowed to settle in the sedimentation tank to obtain the supernatant. It has been released. Therefore, it is necessary to ingest organic matter and maintain microorganisms with good sedimentation. These microorganisms are roughly classified into aggregating microorganisms and filamentous microorganisms. Of these, if the filamentous microorganisms reproduce too much (called the bulking phenomenon), the sedimentation property will deteriorate.

[Problems to be Solved by the Invention]

In the method described in JP-A-62-50607 and 62-50608, sample exchange and cleaning are performed by air injection, but when immersed in sludge for a long time in the sewage treatment plant air tank tank. The dirt on the imaging surface (observation window) cannot be removed completely by air injection. Since this stain affects the image processing measurement value, there is a problem that the reliability of the measurement value decreases.

It is an object of the present invention to provide a microorganism measuring device that image-processes and measures a microorganism with high accuracy and reliability by obtaining a stable microorganism image for a long time.

In order to solve this drawback, JP-A-62-50607, 62-50608
In this issue, a method for measuring microorganisms is proposed. In these methods, a submerged imaging device is used to image a group of microorganisms and an image processing technique is applied to measure filamentous microorganisms and motile microorganisms.

[Means for Solving the Problems]

The above object can be achieved by executing image processing in a sequence of cleaning the imaging surface and executing image processing after replacing the sample. That is, the present invention is an image pickup apparatus which is arranged in a liquid containing microorganisms and which converts luminance information of a microorganism image into an electric signal, an image processing apparatus which recognizes microorganisms based on an image signal output from the image pickup apparatus, and A microbe to be imaged by the imaging device, comprising: an imaging control device that transmits an image signal output from the imaging device to the image processing device and outputs a control command to the imaging device in response to a command from the image processing device. In the sample measuring chamber provided with a sample chamber, the sample chamber is provided with a light projecting window for projecting light from an illuminating device and an observation window for capturing a microbe image, and an air blowing means for the sample chamber, The imaging control is provided with a means for ultrasonically cleaning the observation window such as a light projecting window, a part of the sample chamber is configured with a plunger, and a driving device for the plunger. The apparatus is provided with a timing circuit for controlling the timing so that the ultrasonic cleaning is performed and then the plunger is driven to increase the slit width of the sample chamber to blow the air and then to image the microorganisms. It is a characteristic microbe measuring device.

[Action]

This microorganism measuring device has a timing circuit for synchronizing cleaning, stumbling, and image acquisition. This timing circuit controls three signals of a cleaning command, a sampling command, an image acquisition and a measurement command. A stable image can always be obtained by always cleaning and replacing the sample before image processing measurement.

EXAMPLES Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a sewage treatment process.

In Fig. 1, an aeration tank 100 has a settling tank 1
Returned sludge (microorganisms) flows in from the supernatant liquid (sewage) 10 and the sludge return pipe 160. On the other hand, the blower 120 sends air through the air pipe 130, and the air diffuser 140 sends the air to the air tank 100.
Supply air to. The returned sludge and wastewater supplied into the aeration tank 100 are agitated and mixed. The returned sludge, that is, activated sludge, is an aggregate of microorganisms and has a particle size of 0.1 mm to 1.0
A mass (flock) of around mm contains dozens of microorganisms, but when roughly classified, it consists of aggregating microorganisms and filamentous microorganisms. Activated sludge absorbs oxygen in the supplied air and decomposes organic matter in wastewater into carbon dioxide gas and water. A part of the organic matter is applied to the bacterial growth of the activated sludge. The mixed liquid of activated sludge and sewage is guided to the settling tank 150, where the activated sludge settles by gravity. The supernatant is usually discharged after chlorine sterilization.
On the other hand, the settled sludge is returned from the sludge return pipe 160 to the aeration tank 100 as return sludge.

The imaging device 200 is arranged so as to be immersed in the liquid in the air tank 100, and has a function of obtaining an enlarged image of the microorganisms in the air tank 100. The imaging control device 300 is the imaging device 200
Industrial TV camera (ITV), lighting, cleaning inside. Controls each sampling function. The imaging control device 300 transmits an enlarged image (grayscale image) of the mixed liquid (including water and microorganisms) obtained by the imaging device 200 to the image processing device 400. In addition, when a cleaning command is received from the image processing device 400, the imaging device 200
In contrast, when the ultrasonic cleaning command is output and the sample command is received, the plunger drive command and the compressor 310
To deliver air.

The image processing device 400 outputs a control signal of the image pickup device 200 to the image pickup control device 300, and also performs image processing on the received grayscale image to measure the length of filamentous microorganisms, the size of aggregating microorganisms, and the like.

The keyboard 900 inputs numerical values such as image processing parameters used in the image processing apparatus 400.

The console display 910 displays numerical values input by the keyboard 900 and image processing measurement values.

The monitor TV 920 displays the image of the imaging device 200,
The image processing process and the image processing result are displayed.

FIG. 2 shows a schematic diagram of the microorganism image. The microorganisms in the activated sludge consist of a flocculating microorganism c and a filamentous microorganism f.

FIG. 3 shows a detailed configuration of the image pickup apparatus 200.

In FIG. 3, the light of the illumination device 207 is projected onto the mixed liquid containing the activated sludge and the sewage filled in the sample chamber 220.
Irradiated through 04. The irradiation light is guided to an industrial television camera (ITV) 210 through an observation window 203 provided in a waterproof case 201 and an optical magnifying device 209, where a grayscale image of the mixed liquid is recognized and converted into an electric signal. The image sensor in the ITV210 generates a signal (video signal) having a different output voltage according to the degree of brightness (luminance) received. IT in this way
Video signals are output from V210.

The illumination device 207 is operated by the imaging control device 300 to adjust its illuminance as needed.

The ultrasonic cleaning piezoelectric element 206 generates ultrasonic waves in response to a cleaning command signal from the imaging control device 300, and the projection window 202 and the observation window 2
The surface of 03 is ultrasonically cleaned.

The imaging controller exchanges the mixed liquid in the sample chamber 220 in the following procedure. First, a plunger drive signal is transmitted to the plunger drive device 208 to move the plunger 202 to widen the slit width of the sample chamber. Next, the compressor 310 is controlled to supply air into the sample chamber 220 through the air tube 205 to replace the mixed solution.

FIG. 4 shows a detailed configuration of the image processing device 400.

This example is an example of image processing measurement of filamentous microorganisms.

In FIG. 4, the image processing device 400 includes a timing circuit 4
01, A / D converter 500, image memory 600, image processing processor 70
0 and an arithmetic unit 800.

The timing circuit 401 controls the timing of cleaning the image capturing apparatus 200, exchanging samples, and starting image processing. Details of the timing will be described later.

The image memory 600 includes a grayscale image memory 610 and two binary memos 62.
It consists of 0,630. The image processing processor 700 is for recognizing filamentous microorganisms from a grayscale image, and includes a histogram processing circuit 710, a binarization circuit 720, and a thinning circuit 730.
The computing device 800 is for computing the length from the filamentous microorganisms recognized by the image processing processor 700, and includes a filamentous microorganism integrating circuit 810, a filamentous microorganism length computing circuit 820, an average length computing circuit 830 and a concentration. It comprises an arithmetic circuit 840.

In this configuration, the analog video signal V of the A / D converter 510
Is A / D converted to a digital signal. A / D converter 51
A value of 0 is converted into a brightness digital value of each pixel on the screen. The digital value is 128 levels, for example.
The grayscale image memory 610 stores all digital signals (grayscale image information of the mixed liquid) having the brightness corresponding to each pixel. The frequency of storing the grayscale image information in the grayscale image memory 610 by A / D converting the video signal V is the same as the frequency of air supply to the sample chamber 220. That is, after the mixed liquid is replaced and a new mixed liquid enters the sample chamber 220 and stands still, this grayscale image is stored in the grayscale image memory 610. In this way, the length of the filamentous microorganism is calculated by image processing based on the grayscale image information stored in the memory 610.

Next, the image processing operation in the image processing processor 700 will be described.

The histogram processing circuit 710 calculates a histogram of the grayscale image information stored in the grayscale image memory 610, that is, a density frequency distribution. Histogram is a predetermined density (luminance)
6 is a characteristic diagram showing that some pixels of
As shown in the figure, the horizontal axis represents density (luminance) and the vertical axis represents frequency (number of pixels). The grayscale image in the grayscale image memory 610 is
As shown in FIG. 2, a light background (water) b, a darker aggregating microorganism c, a filamentous microorganism f, and a noise n are included. As shown in FIG. 6, the histogram of the grayscale image shows a portion b corresponding to a bright background and a portion (c + f + n) corresponding to agglutinating microorganisms, filamentous microorganisms and noise.
It is divided into

The binarization circuit 720 determines a binarization threshold T based on the histogram of the grayscale image obtained by the histogram processing circuit 710, and produces grayscale images having various brightnesses (for example, 128 gradations) in black and white. Binarize to and. Pixels brighter than the threshold T are made white (“1” level), and dark pixels are made black (“0” level). The threshold value T is set to a value lower than the peak p of the background portion b by a predetermined value, or set to the inflection point q in FIG.

An example of an image binarized by selecting the threshold T in this way is shown in FIG. In FIG. 6, the background b is white (“1” level), and the aggregating microorganism c, the filamentous microorganism f and the noise n are black (“0” level). The "0" level is indicated by hatching. The obtained binary image is stored in the binary memory 620.

The binary image signal in the binary memory 620 is applied to the thinning circuit 730. The thinning circuit 730 thins the binarized image in the binary memory 620 a plurality of times to extract thread-feeding microorganisms.
As shown in FIG. 2, the filamentous microorganism f is a flocculating microorganism c.
It is contained in the inside of the aggregating microorganism c. Since the filamentous microorganisms f contained in the aggregating microorganisms c overlap with the aggregating microorganisms c, the binarized image of FIG. 6 includes the filamentous microorganisms f and the aggregating microorganisms. The thinning process is executed a plurality of times in order to extract only filamentous microorganisms f from the binarized image of FIG. The thinning process is performed when the binarized image data in the binarized memory 620 is updated.

When the binarized image of FIG. 6 is thinned by one stroke, it becomes as shown in FIG. The thinning circuit 730 performs thinning processing by a known thinning method. Filamentous microorganisms f
And the agglutinating microorganism c (hatching part in Fig. 6)
Pixel by pixel from the contour of. At this time, the pixel is not deleted in the place where there is only one pixel. For example, if the thickness is 3 pixels, one pixel is trimmed from both sides to become 1 pixel, and if the thickness is 2 pixels, one pixel on one side is trimmed to become 1 pixel.

By such a thinning process, the filamentous microorganism has a thickness of 1
Or, a pixel having 3 pixels has 1 pixel, and a pixel having a thickness of 4 pixels or more has 2 pixels or more. The binary image thus thinned for the first time is stored in the binary image memory 630. The binarized image stored in the binarized image memory 630 is further thinned several times in order to make one pixel a portion having two or more pixels in the first thinning process. By repeating this, the filamentous microorganism f becomes an image in which the thickness is all 1 pixel.
At that time, the filamentous microorganism f overlapping the aggregating microorganism c
Cannot be trimmed to more than one pixel by the thinning process, so that the image will end up as shown in FIG. In this way, even filamentous microorganisms having a thickness of 2 to 3 pixels can be extracted with all pixels having a thickness of 1 pixel. The number of repetitions of the thinning process can be determined by the number of pixels of the diameter of the aggregating microorganism. For example, 25 for aggregated microorganisms with a diameter of 50 pixels.
If the line is thinned, it can be made up to 1 pixel. However, in the thinning process, the object is not thinned to one pixel or less, so there is no problem even if it is performed twice or more. However, in order not to repeat more than necessary, the binarized images before and after the thinning process are compared (difference) to determine whether or not they are the same, and when they are the same (images that cannot be further thinned), It is also possible to stop the conversion.

As indicated by n in FIG. 8, the binarized image extracted by such a thinning process also includes small aggregating microorganisms that do not contain filamentous microorganisms (small in quantity). Therefore, when calculating the length from the recognized filamentous microorganism, the microorganism n
Is desirable to be removed.

Returning to FIG. 4, the operation of the arithmetic unit 800 for calculating the length from the number of pixels of the filamentous microorganism will be described.

The filamentous microorganism integrating circuit 810 integrates the number of pixels of the filamentous microorganism extracted as one pixel in thickness in the grayscale image at time t. Specifically, in the binarized image obtained in FIG. 8, the number of pixels only in the hatched portion (pixels having a value of “0” level) is integrated. The total number of pixels is F
(T). The filamentous microorganism length calculation circuit 820 calculates the length L (t) of the filamentous microorganism by the following formula from the integrated pixel number F (t) of the filamentous microorganism.

L (t) = A · F (t) −B (1) Here, A and B are coefficients, and B corresponds to the microorganism image n portion of FIG. 8 to be subtracted as an error. Further, the coefficient A becomes 0.01 when the length of one side of one pixel corresponds to, for example, 10 μm (0.01 mm). By the way, the coefficient A when the filamentous microorganisms are arranged horizontally or vertically as shown in FIGS. 9 (a) and 9 (b) is 0.01, but as shown in FIGS. 10 (a) and 10 (b). , When going up to the right and going up to the left at an angle of 45 degrees, the value of coefficient A is become. If the filamentous microorganisms are evenly distributed horizontally and vertically and to the right and to the left at an angle of 45 degrees, the number of horizontal and vertical pixels is the same as the number of pixels to the right and left it is conceivable that. In this case, the value of A is 0.01 It becomes 0.012 of the average value of.

In this way, when the timing circuit 401 receives the second sampling timing after the measurement for the grayscale image of one screen is completed, the grayscale image is A / D converted by the same operation as described above, and the time The image is stored in the grayscale image memory 610 at t + h (where h is a sampling period), and the same processing is repeated in the image processing processor 700.
The filamentous microorganism length obtained by this second treatment is L (t +
h). In this way, the filamentous microorganism length calculation circuit
At 820, the lengths L (t + h), L (t + 2) of the filamentous microorganisms in the respective images at time t, t + h, t + 2h, ...
h), ... L (t + Kh) is calculated one after another at each time h.

The timing control of the imaging device 200 by the imaging control device 300 is performed in conjunction with the image processing device 400.

In response to the signal from the filamentous microorganism length computing circuit 820, the average computing circuit 830 computes the average length of the filamentous microorganisms per screen. The average length calculation circuit 830 is a signal output from the filamentous microorganism length calculation circuit 820. L (t + h), L (t + 2
From h), ... L (t + Kh), calculate the average length Lm of the filamentous microorganisms per screen by the following formula.

Here, (K + 1) is the average number of times, which is about 10 to 1000 times.

In response to the signal Lm of the average length calculation color 830, the concentration calculation circuit 840 calculates the filamentous microorganism length per unit volume (that is, filamentous microorganism concentration) Lv by the following equation.

Lv = Lm / (K + 1) / v (3) Here, v is the volume of the imaged mixed liquid.

Through the above processing, the filamentous microorganism length (concentration) per unit volume can be obtained.

As described above, the concentration (amount) of filamentous microorganisms is obtained. In the present invention, binarization is performed based on the histogram of the concentration image, and the binarized image is thinned and then the filamentous microorganisms Since the length is calculated, the length of the filamentous microorganism contained in the aggregating microorganism can also be accurately measured.

FIG. 11 shows the timing circuit 401 for cleaning timing,
The sample exchange timing, the A / D conversion of the grayscale image, and the image processing timing are shown. FIG. 11 shows an example in which one cycle of these is performed at time h. One cycle of measurement is cleaning. Plunger drive and air sampling are performed, and A / D conversion and image processing are performed in this order. This cycle is repeated. The replacement of the wash sample and the setting of the image processing start timing can be easily changed with the keyboard 900.

〔The invention's effect〕

According to the present invention, the image pickup surface is washed before the image processing is executed, so that stable images can be continuously obtained. Therefore, microorganisms can be measured with high accuracy.

In addition, although the above-mentioned example demonstrated the example applied to the sewage treatment process, this invention can be applied also to the microorganism measurement in other bioprocess which cultures a microorganism.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a grayscale image, FIG. 3 is a detailed explanatory diagram of an imaging device 200, and FIG. 4 is a detailed explanatory diagram of an image processing device 400. 5 to 11
The figure is an illustration of the image processing operation. 100 ... Air tank, 200 ... Imaging device, 300
...... Imaging control device, 400 ...... Image processing device, 401 ...... Timing circuit, 206 ...... Piezoelectric element for ultrasonic cleaning.

Front Page Continuation (72) Inventor Kenji Baba 4026 Kujimachi, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Co., Ltd. (56) References JP 62-50607 (JP, A) JP 61-126427 (JP JP, A)

Claims (1)

[Claims] 1. An imaging device arranged in a liquid containing microorganisms for converting luminance information of a microorganism image into an electric signal, an image processing device for recognizing microorganisms based on an image signal output from the imaging device, and the imaging. An image pickup control device that transmits an image signal output from the device to the image processing device and outputs a control command to the image pickup device in response to a command from the image processing device, A microorganism measuring device comprising a sample chamber for taking in a light, a light projecting window for projecting light from an illuminating device and an observation window for taking in a microorganism image provided in the sample chamber, and a device for blowing air into the sample chamber. A means for ultrasonically cleaning the light window and the observation window is provided, a part of the sample chamber is configured with a plunger, and a drive device for the plunger is provided, and the imaging control device is provided with After ultrasonic cleaning, the plunger is driven to enlarge the slit width of the sample chamber to blow the air, and then a timing circuit is provided to control the timing so as to image the microorganisms. Microorganism measuring device.