JP5565998B2 - Optical fiber counting device - Google Patents

Description

  The present invention relates to an optical fiber strand counting device that counts the number of normal optical fiber strands from an image of an optical fiber used in, for example, a biological light measurement device.

  As a conventional optical fiber inspection device, for example, an optical fiber end surface inspection device is known. In this optical fiber end face inspection apparatus, the end face of the optical fiber held by the optical fiber holder is irradiated with a laser beam. Then, the laser beam reflected by the end face is received by the screen, and the inclination of the end face of the optical fiber is measured based on the position of the laser light spot in the screen (see, for example, Patent Document 1).

  Moreover, a biological light measuring device is known as a device using an optical fiber. The biological optical measurement device is a device that can easily measure blood circulation, hemodynamics, and hemoglobin amount change inside a living body with low restraint on a subject.

  In the biological light measuring device, in order to transmit near-infrared light to a living body and to receive light reflected inside the living body, a large number (for example, 720) of optical fiber strands having a diameter of 50 μm made of multicomponent glass. A plurality of bundle-type optical fibers including are used. By using such a thin optical fiber, flexibility is increased and it is possible to cope with movement of the subject, so that it can be applied to diagnosis of children and infants.

  Since the irradiation light and the detection light are transmitted by the optical fiber strand, the measurement data greatly depends on the number of normal optical fiber strands in the optical fiber. That is, when the number of disconnected optical fiber wires increases, highly accurate measurement data cannot be obtained.

  Therefore, conventionally, in order to confirm the number of normal (not disconnected) optical fiber strands, a method of counting the number of optical fiber strands using a microscope (installation type) and a portable light has been implemented. It had been. This method irradiates one end surface of an optical fiber with a portable light, and magnifies the other end surface of the optical fiber with a microscope (approximately 200 times), and manually calculates the number of optical fiber strands from the captured image. It is an inspection method that counts in

JP 2003-194667 A

  However, in the conventional optical fiber strand counting method as described above, since it is necessary to manually count the number of optical fiber strands from the captured image of the end face of the optical fiber, it takes considerable time. In particular, in the biological light measurement device, since a large number of thin optical fiber strands are bundled and used, it takes a long time to count the optical fiber strands. For example, an inexperienced inspection engineer who is inspecting for the first time required about 5.75 hours for a set of optical fibers. Moreover, even an inspection engineer with a certain degree of experience required about 4 hours. In addition, the current biological light measurement device has a specification that allows the addition of up to five sets of optical fibers, and therefore requires a maximum of about 20 hours for inspection. Furthermore, in the visual confirmation, the counting accuracy of the number of optical fiber strands is also low.

The present invention has been made to solve the above-described problems, and can easily and accurately count the number of optical fiber strands in a short time, thereby preventing blurring and variations. Who aims to obtain an optical fiber counting device also Ru can get the same optical fiber image is performed.

In order to solve the above problems, an optical fiber strand counting device of the present invention is configured as follows.
A connection part for holding one end of each of the optical fibers for irradiation and detection used in a biological light measuring device configured with an optical fiber including a plurality of optical fiber strands; a holder for arranging the connection part; A flat light source that allows inspection light to be incident on one end of the connected optical fiber when one end of at least one of the optical fiber for irradiation or detection is connected to the connecting portion and accommodated in the holder And the state of the connected optical fiber using image data acquired by a camera that observes the other end of the connected optical fiber when inspection light is incident from the flat light source unit. And an arithmetic processing unit that outputs to a display, wherein the arithmetic processing unit performs binarization processing on the image data using a threshold value having a predetermined pixel value. Compression that performs separation into an optical fiber strand portion and a background portion, and converts the pixel into a background portion when the pixel is adjacent to the pixel among the pixels separated as the optical fiber strand portion. Processing, adding a number to each of the optical fiber strands individually separated in the compressed image data, counting the number of normal optical fiber strands using the added number, The state of the connected optical fiber is output to the display using the ratio between the number of the optical fibers and the number of optical fiber strands input in advance.

The optical fiber strand counting device of the present invention can count the number of optical fiber strands easily and with high accuracy in a short time, can prevent blurring and variation, and the same optical fiber can be used by anyone. image Ru can be obtained an optical fiber counting device that can get a.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a basic configuration of a biological light measurement device. In the figure, a probe holder 2 is mounted on the head of a subject 1. The probe holder 2 holds a plurality of irradiation probes (not shown) and a plurality of detection probes (not shown). Irradiation probes and detection probes are alternately arranged in a matrix.

  Near-infrared light generated by the light source unit 5 is irradiated onto the subject 1 through a plurality of irradiation optical fibers 6. The tip of each irradiation optical fiber 6 is attached to the probe holder 2 via an irradiation probe.

The light source unit 5 includes a semiconductor laser 3 that emits light of a predetermined wavelength, and a plurality of optical modules 7 that modulate light from the semiconductor laser 3. Each optical module 7 has a modulator (not shown) that modulates light from the semiconductor laser 3 at different frequencies. The wavelength of light depends on the spectral characteristics of the target substance in the living body, but when measuring oxygen saturation and blood volume from the concentration of Hb and HbO ₂ , one or more wavelengths are selected from the wavelength range of 600 nm to 1400 nm. Selected and used.

  The light that has been irradiated onto the subject 1 from the irradiation optical fiber 6 and passed through the subject 1 is sent to the optical measurement unit 8 via the plurality of detection optical fibers 4. The tip of each detection optical fiber 4 is attached to the probe holder 2 via a detection probe.

  The optical measuring unit 8 selectively selects a plurality of photoelectric conversion elements 9 such as photodiodes that generate an electric signal according to the detected amount of passing light, and a corresponding modulation signal from the electric signal from the photoelectric conversion element 9. It has a lock-in amplifier module 10 to detect, and an A / D converter 11 that converts an output signal of the lock-in amplifier module 10 into a digital signal.

  For example, when two types of oxygenated hemoglobin and deoxygenated hemoglobin are measured, light of two wavelengths of 780 nm and 830 nm are generated, and these lights are combined to be analyzed from one irradiation optical fiber 6. 1 is irradiated. The lock-in amplifier module 10 selectively detects modulation signals corresponding to these two wavelengths. As a result, a hemoglobin amount change signal that is twice the number of channels is obtained for the measurement position located between the irradiation position of the light from the irradiation optical fiber 6 and the detection position of the passing light by the detection optical fiber 4. It is done.

  The light source unit 5 and the optical measurement unit 8 are controlled by the control unit 12. The control unit 12 is configured by a computer, for example, and includes a control unit main body 13, a storage unit 14, an input / output unit 15, and a signal processing unit 16. The signal processing unit 16 processes the hemoglobin amount change signal converted into the digital signal, and displays a graph showing the oxygenated hemoglobin concentration change, the deoxygenated hemoglobin concentration change, the total hemoglobin concentration change, etc. for each channel and the subject 1 Create an image plotted on the two-dimensional image.

  The storage unit 14 records data and processing results necessary for processing by the signal processing unit 16. Various commands necessary for the operation of the control unit 12 are input to the input / output unit 15. Connected to the signal processing unit 16 is a display unit 17 that displays an image created by the signal processing unit 16.

  Each of the optical fibers 4 and 6 includes a large number (for example, 720) of optical fiber strands having a diameter of 50 μm made of multicomponent glass.

  FIG. 2 is a block diagram showing an optical fiber counting device according to Embodiment 1 of the present invention. An optical fiber strand counting device includes an inspection light incident part (measuring jig) 21 for injecting inspection light from one end of optical fibers 4 and 6, a support base 22 for holding the other end of optical fibers 4 and 6, light A microscope (small microscope) 23 that receives inspection light emitted from the other ends of the fibers 4 and 6 and a counter main body 24 that captures image information from the microscope 23 are provided.

  The inspection light incident section 21 includes a flat light source section (not shown) that generates inspection light and a holder (housing) 25 that holds one end of the optical fibers 4 and 6 so as to face the light source section. Have. The light source unit is accommodated in the holder 25. Further, a fluorescent lamp can be used as the light source unit.

  The holder 25 is configured to have a bottom area of about B5 paper, a height (thickness) of about 2 cm, and a weight of about 1 kg, and can be carried. Further, the outer peripheral portion of the holder 25 is covered with a light shielding member (for example, an aluminum foil).

  A plurality of irradiation optical fiber connection portions 25 a and a plurality of detection optical fiber connection portions 25 b are provided on the upper portion of the holder 25. Each irradiation optical fiber connecting portion 25a is provided with a connector similar to the connector for connecting the irradiation optical fiber 6 provided in the light source portion 5 of the biological light measuring device. Each detection optical fiber connection portion 25b is provided with a connector similar to the connector for connection of the detection optical fiber 4 provided in the optical measurement portion 8 of the biological light measurement device.

  As shown in FIG. 3, the diameter of the irradiation optical fiber connection portion 25a is larger than the diameter of the detection optical fiber connection portion 25b. Further, the irradiation optical fiber connection portion 25 a and the detection optical fiber connection portion 25 b are arranged in different regions on the holder 25.

  The microscope 23 is disposed so as to face the upper surface of the support base 22. The other ends of the optical fibers 4 and 6 are held on the support base 22 so as to face the microscope 23. The inspection engineer observes the end faces of the optical fibers 4 and 6 through the microscope 23 and images the end faces of the optical fibers 4 and 6 with the microscope 23 when it is determined that it is suitable for photographing.

  The microscope 23 is directly connected to the counting device main body 24 (for example, USB 2.0 connection). Moreover, the microscope 23 can project a high-resolution (800 × 600 dot) enlarged image of SVGA (Super Video Graphics Array) (the magnification can be arbitrarily changed from 1 to 300 times). Furthermore, the microscope 23 is a compact design in which a CCD camera, illumination, and a lens are integrated, and can be easily carried.

  The counting device main body 24 includes a computer having an arithmetic processing unit (CPU and the like), a storage unit (ROM, RAM, hard disk and the like), and a signal input / output unit. That is, the function of the counting device main body 24 can be realized by a computer. The counting device main body 24 includes a display 26, a keyboard 27, and a mouse 28.

  The computer of the counting device main body 24 stores a program (counting software) for processing image data of an optical fiber image taken from the microscope 23. The image processing performed by the counting device main body 24 includes three processes: binarization processing (threshold processing), shrinkage processing (Erosion), and labeling processing.

  First, in the binarization process, a specific region, that is, a region of an optical fiber, is extracted from the 24-bit color bmp image data, and thereby the optical fiber image is divided into an optical fiber portion and a background portion.

  Here, unlike an analog image, a digital image expresses luminance (color information) independently for each pixel. The binarization process is a process of converting the luminance of each pixel into two values of black and white with a certain reference value. This reference value is called a threshold value (Threshold = TH).

  RGB values of 0 to 255 are stored in each pixel of the captured bmp image, and the average value of the RGB values is the brightness of each pixel. In addition, the image after the binarization process differs depending on the reference threshold value. Here, the threshold value is determined using a mode method based on the density histogram of each image.

  FIG. 4 is a graph showing an example of the relationship between the density histogram of the optical fiber image obtained by the microscope 23 of FIG. 2 and the pixel value. The density histogram of an image has two peaks corresponding to an object (here, an optical fiber) and a background. That is, the density histogram has bimodality. In the mode method, the position of a valley between two peaks of the density histogram is set as a threshold value.

  Next, in the shrinking process, pixel values located at the outer periphery of the optical fiber strand portion of the binarized image data are converted into pixel values of the background portion, and the periphery of the optical fiber strand portion is shrunk by one pixel. It is done. That is, if even one pixel value exists in the vicinity of a certain pixel, the pixel value of that pixel is set to 0, and the other pixel values are set to 255. Thereby, noise existing in the image is removed, and adjacent optical fiber strand portions are separated.

  FIG. 5 is an explanatory view showing an enlarged part of the optical fiber image before the shrinking process, and FIG. 6 is an explanatory view showing a state after the shrinking process is performed on the image of FIG. The noise portion 29 in FIG. 5 has been removed by the shrinking process. In FIG. 6, the hatched portion is the optical fiber strand portion (pixel value 255), the white portion is the background portion (pixel value 0), and the two optical fiber strand portions connected in FIG. It is separated.

  FIG. 7 is an explanatory diagram illustrating an example of the entire optical fiber image before the contraction process, and FIG. 8 is an explanatory diagram illustrating a state after the contraction process is performed on the image of FIG. As shown in FIGS. 7 and 8, by performing the contraction process, each of the optical fiber strands can be clearly identified.

  In the contraction process, a lump of noise of up to 100 pixels (10 × 10 pixels) can be removed, and fine noise can be almost completely removed. Note that the average number of pixels of one optical fiber is 260 pixels (16 × 16 pixels).

  Next, in the labeling process, a number is added to the portion of the optical fiber in the optical fiber image. Specifically, among the pixels having a pixel value of 255, all the adjacent pixels (connected components) are assigned the same label (number), and different connected components are assigned different numbers. .

  FIG. 9 is an explanatory diagram showing an enlarged part of the optical fiber image before the labeling process, and FIG. 10 is an explanatory diagram showing a state after the labeling process is performed on the image of FIG. By assigning numbers to the connected components independent from each other as shown in FIG. 9 in order from 1 as shown in FIG. 10, the number assigned last is obtained as the number of normal optical fiber strands. Can do. In addition, as a labeling process, the labeling process by 4 vicinity (up and down, right and left) which is a typical method can be used.

  FIG. 11 is a flowchart showing the operation of the counting device main body 24 of FIG. When an optical fiber image is captured from the microscope 23 and image processing is started, the counting device body 24 determines and sets a threshold value by the mode method (step S1). When the threshold is set, the optical fiber image is divided into an optical fiber strand portion and a background portion by binarization processing (step S2). Thereafter, noise existing in the optical fiber image is removed by shrinkage processing, and adjacent optical fiber strand portions are separated (step S3).

  After the shrinking process, a number is added to the optical fiber portion in the optical fiber image by the labeling process (step S4), and the last number is output as the number of normal optical fiber strands (step S5). ). The inspection engineer determines whether or not the optical fibers 4 and 6 can be used according to the number of normal optical fiber strands. For example, the optical fibers 4 and 6 are determined to be defective when the number of disconnected optical fiber strands exceeds 50% of the total.

  In such an optical fiber strand counting device, by binarizing the image data of the optical fiber image, the optical fiber image is divided into an optical fiber strand portion and a background portion, and the optical fiber strand in the optical fiber image is divided. Since numbers are added to the wire portions, the number of optical fiber strands can be counted easily and with high accuracy in a short time. That is, since the number of optical fiber strands is automatically counted by counting software using image processing, it is possible to reduce inspection labor, inspection time, and inspection man-hours compared with the case of counting visually. . For example, the inspection man-hour can be reduced to about 1/10 of the conventional one.

In addition, since the shrinking process is performed as a pre-process of the labeling process, the noise component can be removed, and the optical fiber strands can be separated one by one, and a highly accurate image processing analysis can be performed. .
Furthermore, since the inspection light incident part 21 having the flat light source part and the holder 25 that holds the ends of the optical fibers 4 and 6 is used, it becomes possible to prevent blurring and variation, and anyone can implement it. The same photographed image can be acquired.
Furthermore, by using the microscope 23 connected to the counting device main body 24 by USB, the image data of the optical fiber image can be easily taken into the counting device main body 24, and there are no restrictions on the inspection place. It can be applied to field inspections. For this reason, a quick response to the customer when a problem occurs can be realized.

In the above example, the optical fiber strand counting device is used for the inspection of the optical fibers 4 and 6 used in the biological light measurement device, but it can also be used for the inspection of the optical fiber used in other devices. However, since the biological optical measuring device uses an optical fiber in which many small-diameter optical fiber strands are bundled as described above, it is particularly effective to use the optical fiber strand counting device of the present invention.
In addition, the control unit of the biological light measurement device can have the function of the counting device main body, and a microscope and an inspection light incident unit can be attached to the biological light measurement device.
Furthermore, the counting result of the optical fiber may be output as the number, or the entire number may be input in advance and output as a normal optical fiber rate or disconnection rate.

It is a block diagram which shows the basic composition of a biological light measuring device. BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the optical fiber strand counting apparatus by Embodiment 1 of this invention. It is a top view which shows the holder of FIG. It is a graph which shows an example of the relationship between the density histogram of the optical fiber image obtained by the microscope of FIG. 2, and a pixel value. It is explanatory drawing which expands and shows a part of optical fiber image before a shrink process. FIG. 6 is an explanatory diagram illustrating a state after performing a contraction process on the image of FIG. 5. It is explanatory drawing which shows an example of the whole optical fiber image before a shrinkage | contraction process. It is explanatory drawing which shows the state after performing the shrinkage | contraction process to the image of FIG. It is explanatory drawing which expands and shows a part of optical fiber image before a labeling process. It is explanatory drawing which shows the state after implementing a labeling process to the image of FIG. It is a flowchart which shows operation | movement of the counting device main body of FIG.

Explanation of symbols

  4 optical fiber for detection, 6 optical fiber for irradiation, 21 inspection light incident part, 24 counting device main body, 25 holder.

Claims (3)

A connection part for holding one end of each of the optical fibers for irradiation and detection used in a biological light measuring device configured with an optical fiber including a plurality of optical fiber strands; a holder for arranging the connection part; A flat light source that allows inspection light to be incident on one end of the connected optical fiber when one end of at least one of the optical fiber for irradiation or detection is connected to the connecting portion and accommodated in the holder And the state of the connected optical fiber using image data acquired by a camera that observes the other end of the connected optical fiber when inspection light is incident from the flat light source unit. An optical fiber counting device having an arithmetic processing unit for outputting to a display,
The arithmetic processing unit separates the image data into an optical fiber strand portion and a background portion by a binarization process using a threshold value having a predetermined pixel value, and the pixels separated as the optical fiber strand portion of, if the pixels adjacent to the pixel is the background section, it performs contraction processing for converting the pixel in the background section, each optical fiber unit which is individually separated in said contraction-processed image data The number of normal optical fiber strands is counted using the added number, and the connected light is calculated using the ratio between the counted number and the number of optical fiber strands input in advance. An optical fiber counting device that outputs a fiber state to a display.   2. The optical fiber according to claim 1, wherein a diameter of a connection portion that holds one end portion of the irradiation optical fiber is larger than a diameter of a connection portion that holds one end portion of the detection optical fiber. Wire counting device.   The optical fiber strand counting device according to claim 1 or 2, wherein the outer peripheral portion of the holder is covered with a light shielding member using an aluminum foil.

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