JP6428728B2 - Foreign matter detection device and foreign matter detection method in powder using terahertz pulse wave - Google Patents

Description

  The present invention relates to a foreign matter detection device and foreign matter detection method in powder, and more particularly, to a foreign matter detection device and foreign matter detection method in powder housed in a container made of a resin sheet such as PE or PP and an aluminum sheet.

  Conventionally, it has two chambers separated by isolation means that can communicate, one of which is filled with excipients such as glucose and lactose and a powder of a pharmaceutically active substance, and the other chamber is filled with a solution. Drug containers and powder containers are known.

  According to such a container, the drug powder and the solution can be separated and stored until immediately before use, and the powder is dissolved in the solution by applying pressure from the outside to communicate both chambers immediately before use. To obtain a chemical solution.

  By the way, although the foreign substance may rarely mix in the powder in such a container, since the foreign object should not be overlooked from the purpose of use, the foreign substance inspection at the time of manufacture becomes indispensable.

  Conventionally, for example, a visual inspection by an inspector is performed by placing a container on a vibrator and causing foreign matter to rise from the powder by vibration. However, visual inspection may take a considerable amount of time, and foreigners may be missed if not skilled. Further, in the case of powder having poor fluidity, foreign matter may not be lifted by vibration, and such visual inspection is inappropriate. The inspection process involving people such as inspectors may be the rate-limiting stage of production, and unmanned and automated processes are desired.

  According to the inspection apparatus using X-rays, metallic foreign objects can be detected, but it is difficult to accurately detect non-metallic foreign objects such as resin and wood pieces.

  On the other hand, analysis techniques using electromagnetic waves in the terahertz region (for example, see Non-Patent Document 1 and Non-Patent Document 2) are known, and non-destructive inspection devices using terahertz waves are already on the market.

  In addition, a foreign substance inspection apparatus in a granular material using a sub-terahertz electromagnetic wave and an inspection method thereof (see, for example, Patent Document 1) or a substance other than a drug / drug component or drug by using terahertz time domain spectroscopy. A specimen inspection apparatus and a specimen inspection method (for example, see Patent Document 2) that can be reliably detected have also been proposed.

  The foreign matter inspection apparatus in a granular material described in Patent Document 1 is a foreign matter inspection apparatus in a granular material using a sub-terahertz electromagnetic wave, and a pulsed electromagnetic wave having a wavelength of 600 μm to 3 mm (0.5 THz to 100 GHz) is inspected. Electromagnetic wave irradiation means for irradiating an object, detection means for detecting a spatial distribution of the transmitted pulsed electromagnetic wave, signal processing means for obtaining a difference in propagation time or amplitude of the pulsed electromagnetic wave by the inspection object, and And an information processing means for displaying a difference in propagation time or an amplitude difference due to the inspection object.

  The specimen inspection apparatus described in Patent Document 2 includes a terahertz wave generation unit that generates a terahertz wave beam, an optical system that leads the terahertz wave generated by the terahertz wave generation unit to a specimen as an object to be inspected, A detection unit that detects a terahertz output wave transmitted or reflected through the sample as an electrical signal, a spectral spectrum is obtained from the electrical signal detected by the detection unit, and the spectral spectrum and a component specific to the sample that has been obtained in advance And a determination unit that determines whether or not the sample contains a different type or foreign matter based on a spectrum (fingerprint spectrum) obtained by the above method.

JP 2001-066375 A International Publication No. 2008/001785

Ryoichi Fukasawa, “Terahertz Time Domain Spectroscopy and Analytical Chemistry”, Bunkeki, Japan Society for Analytical Chemistry, June 2005, p. 290-296 Ryoichi Fukasawa, “Material analysis by terahertz waves”, Applied Physics, Japan Spectroscopic Society, 2010, Vol. 79, No. 4, p. 312 to 316

  However, in the conventional technology as described above, it is not always possible to accurately detect foreign substances other than metals, such as resins, carbonized chemicals, and hair. In particular, verification of whether or not foreign substances (especially hair) in powders enclosed in drug containers with a packaging surface made of a resin sheet such as PE or PP and a packaging back surface made of an aluminum sheet can be accurately detected. And the optimum conditions for detection have not been found.

  In view of such problems of the prior art, the object of the present invention is to accurately detect foreign matters in powder enclosed in a medicine container whose packaging surface is made of a resin sheet such as PE or PP and whose packaging back surface is made of an aluminum sheet. An object of the present invention is to provide a foreign substance detection device and foreign substance detection method in powder using a terahertz pulse wave.

  In order to achieve the above object, a foreign matter detection apparatus in powder using a terahertz pulse wave according to the present invention includes a first part that transmits most of the terahertz pulse wave and a second part that reflects the terahertz pulse wave without transmitting it. A foreign matter detection device for detecting foreign matter in powder contained in a container having a part, an oscillation unit that generates a terahertz pulse wave and emits it as irradiation light, and the irradiation light emitted from the oscillation unit An optical system that guides the reflected light reflected from the container to the first part of the container and outputs a signal corresponding to the reflected light collected by the optical system and also receives an echo A scanning mechanism that two-dimensionally scans the position on the first part where the irradiation light is guided by the optical system, and a time waveform signal output in time series from the receiving unit. Value, a reflection image having each pixel value as a value obtained by integrating the time waveform signal over time, a power spectrum calculated by Fourier transform of the time waveform signal, a tomographic image obtained from the measurement result of the echo, and the time waveform signal A calculation unit for detecting foreign matter (presence / absence and type, etc.) in the powder in the container based on at least one of frequency images in which each pixel value is a value calculated by Fourier transform. Features.

  Here, the first part may be made of a resin sheet on the first surface side of the container, and the second part may be made of an aluminum sheet on the second surface side opposite to the first surface side of the container. . Examples of foreign substances include, but are not limited to, hair as well as metals and resins.

  According to the foreign substance detection apparatus having such a configuration, although the terahertz wave transmits both the first portion of the container and the powder to be sealed, the transmittance of the foreign substance mixed in the powder is different. Even if the foreign material is not only metal and resin but even hair, it can be accurately detected to a considerable degree of accuracy by combining one or more of time waveform signal, terahertz wave reflection image, power spectrum, tomographic image and frequency image. It becomes possible.

  In the foreign matter detection apparatus of the present invention, the frequency of the terahertz pulse wave is preferably 1 THz or less.

  According to the foreign substance detection apparatus having such a configuration, the terahertz wave transmittance is sufficiently high even if the powder enclosed in the container is a drug containing a pharmaceutically active substance. Will improve.

  Alternatively, the foreign substance detection method in powder using the terahertz pulse wave of the present invention includes a first part that transmits most of the terahertz pulse wave and a second part that reflects without transmitting the terahertz pulse wave. A foreign matter detection method for detecting foreign matter in powder stored in an inside, wherein an oscillation step of generating a terahertz pulse wave to emit as irradiation light, and the irradiation light emitted in the oscillation step of the first of the container A receiving step for guiding reflected light reflected from the container while collecting the reflected light, outputting a signal corresponding to the reflected light thus collected and measuring an echo, and the irradiation light is guided. Each pixel includes a scanning step for two-dimensionally scanning the position on the first part, a value corresponding to the time waveform signal output in time series from the receiving step, and a value obtained by time integration of the time waveform signal. The reflected image, the power spectrum calculated by Fourier transform of the time waveform signal, the tomographic image obtained from the echo measurement result, and the frequency with each pixel value as the value calculated by Fourier transform of the time waveform signal And a calculation step of detecting foreign matter (presence / absence and type) in the powder in the container based on at least one of the images.

  According to the foreign substance detection method having such a configuration, although the terahertz wave transmits both the first portion of the container and the enclosed powder, the transmittance of the foreign substance mixed in the powder is different. Even if the foreign material is not only metal and resin but even hair, it can be accurately detected to a considerable degree of accuracy by combining one or more of time waveform signal, terahertz wave reflection image, power spectrum, tomographic image and frequency image. It becomes possible.

Alternatively, the foreign matter detection device of the present invention is a foreign matter detection device that detects foreign matter in powder, and generates an terahertz pulse wave to be emitted as irradiation light, and the irradiation light emitted from the oscillation portion. An optical system that collects reflected light that is guided to the powder and reflected from the powder and / or transmitted light that has passed through the powder, and according to the reflected light and / or transmitted light that is collected by the optical system. A value corresponding to a time waveform signal output in time series from the receiving unit, a scanning mechanism for scanning the position on the powder where the irradiation light is guided by the optical system, A reflection image in which each pixel value is a value obtained by integrating the time waveform signal over time, a power spectrum calculated by Fourier transform of the time waveform signal, and Fourier transform of the time waveform signal Based on the value calculated by conversion with at least one frequency image to each pixel value, characterized in that it comprises a computing unit for detecting foreign objects in said powder. Alternatively, the foreign matter detection device of the present invention is a foreign matter detection device that detects foreign matter (for example, hair) in powder, an oscillation unit that generates a terahertz pulse wave and emits it as irradiation light, and is emitted from the oscillation unit An optical system that guides the irradiation light to the powder and collects reflected light reflected from the powder and / or transmitted light transmitted through the powder, and the reflected light and / or the light collected by the optical system. A receiving unit that outputs a signal corresponding to transmitted light, a scanning mechanism that scans the position on the powder, where the irradiation light is guided by the optical system, and a time waveform signal that is output in time series from the receiving unit , A reflection image in which each pixel value is a value obtained by integrating the time waveform signal over time, a power spectrum calculated by Fourier transform of the time waveform signal, and the time waveform And a calculation unit for detecting foreign matter in the powder based on at least one of frequency images in which each pixel value is a value calculated by Fourier transform. The powder is a drug containing a pharmaceutically active substance. The frequency of the terahertz pulse wave is 1 THz or less.

  Alternatively, the foreign matter detection method of the present invention is a foreign matter detection method for detecting a foreign matter in a powder, and includes an oscillation step for generating a terahertz pulse wave and emitting it as irradiation light, and the irradiation light emitted in this oscillation step. The reflected light reflected from the powder and / or the transmitted light transmitted through the powder is collected to the powder and a signal corresponding to the collected reflected light and / or the transmitted light is output. A receiving step, a scanning step of scanning a position on the powder to which the irradiation light is guided, a value corresponding to a time waveform signal output in time series from the receiving step, and time integration of the time waveform signal The reflected image having the pixel value as each pixel value, the power spectrum calculated by Fourier transform of the time waveform signal, and the value calculated by Fourier transform of the time waveform signal for each pixel To based on at least one frequency image and characterized in that it comprises a calculation step of detecting the foreign substance of the powder.

  According to the foreign object detection device and the foreign object detection method having such a configuration, even when the powder is not stored in the container, the foreign object mixed in the powder when the terahertz wave transmits or reflects the powder. Because the transmittance is different, even if the foreign material is not only metal or resin but also hair, it can be accurately accurate to a considerable degree by combining one or more of time waveform signal, reflection image, power spectrum, and frequency image It becomes possible to detect.

  According to the foreign matter detection device and foreign matter detection method in powder using the terahertz pulse wave of the present invention, although the terahertz wave passes through the powder, the transmittance of the foreign matter mixed in the powder is different. Even if the foreign material is not only metal and resin but even hair, it can be accurately detected to a considerable degree of accuracy by combining one or more of a time waveform signal, a terahertz wave reflection image, a power spectrum and a frequency image. .

  When the frequency of the terahertz pulse wave is 1 THz or less, the foreign substance detection accuracy is improved even if the powder is a drug containing a pharmaceutical active substance such as an antibiotic.

It is a graph which shows the frequency characteristic of the terahertz wave transmittance | permeability, such as the packaging material of the chemical | medical agent container 20, and the powder enclosed. 1 is an overview of a foreign object detection device 10 according to an embodiment of the present invention. 2 is a schematic explanatory diagram showing the principle of foreign object detection in the foreign object detection device 10. FIG. (A) is a visible image of a measurement sample, (b) is a terahertz wave reflection image, (c) is a tomographic image along the solid line in (b), and (d) is an image illustrating a frequency image. It is explanatory drawing of the conversion process from the time-resolved mapping image to the intensity mapping image by Fourier transformation. It is a graph which illustrates the signal (time waveform signal) output in time series. It is a graph which illustrates the power spectrum obtained by the Fourier transform from the signal (time waveform signal) output in time series. (A) is a visible image showing a drug container containing the powder containing the metal foreign substance and a measurement area, (b) is a terahertz wave reflection image, and (c) to (g) are along each solid line in (b). It is the image which illustrates each tomographic image. (A) is a visible image showing a drug container containing a powder containing this resin foreign substance, (b) is a terahertz wave reflection image, and (c) to (e) are tomographic images along each solid line in (b). It is the image which illustrates each. (A) is a visible image showing a drug container containing a powder containing this resin foreign substance, (b) is a terahertz wave reflection image, and (c) to (e) are tomographic images along each solid line in (b). It is the image which illustrates each. (A) is a visible image showing a drug container containing a powder containing the carbonized drug, (b) is a terahertz wave reflection image, (c) and (d) are tomographic images along each solid line in (b). It is the image which illustrates each. (A) is a visible image showing the arrangement of hair, (b) is a visible image in a state where it is covered with lactose having a thickness of 3 mm, (c) is a terahertz wave reflection image, (d) is a frequency image (0. 62 THz). (A) is the same terahertz wave reflection image as FIG. 12 (c), (b) is an AA ′ tomographic image of (a), and (c) is an example of a BB ′ tomographic image of (a). It is an image to be. 12A is the same visible image as FIG. 12B, FIG. 12B is the same terahertz wave reflection image as FIG. 12C and FIG. 13A, and FIGS. It is an image that exemplifies each frequency image obtained by changing in the range of .1 to 0.8 THz.

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

<Measurement sample>
First, a measurement sample when foreign matter detection is performed according to the present invention will be described. As a measurement sample, for example, it has at least two chambers partitioned by a separating means that can communicate with each other, and at least a part of the packaging surface (first surface) is a resin sheet (first portion) such as PE or PP. An example is a drug container 20 whose back surface (second surface) is made of an aluminum sheet (second portion).

  In the drug container 20, for example, a powder of a drug containing a pharmaceutically active ingredient such as glucose, lactose, or an antibiotic is sealed in one chamber, and a solution is sealed in the other chamber. Immediately before use, pressure is applied from the outside to allow the two chambers to communicate with each other, whereby the powder dissolves in the solution and a chemical solution is obtained.

  FIG. 1 is a graph showing the frequency characteristics of the terahertz wave transmittance of the packaging material of the drug container 20 and the encapsulated powder. Here, a drug powder 20 containing a drug powder composed of sulbactam sodium 1 g (titer) and ampicillin sodium 2 g (titer) is called formulation A, and cefepime hydrochloride hydrate 1 g (titer). Formulation B is obtained by encapsulating a drug powder having a composition of 0.72 g of L-arginine in a drug container 20.

  As shown in this graph, the resin sheet (a) used on the packaging surface of the drug container 20 has almost the same output as the incident wave (IN), and the measured terahertz band (˜2 THz). It has high permeability over almost the entire area.

  On the other hand, the aluminum (b) used on the packaging back surface of the medicine container 20 reflects the terahertz wave with almost no transmission. In addition, pharmaceutical powders such as Formulation A (c, c2) and Formulation B (d) generally transmit low-frequency components in the terahertz band (approximately 1 THz or less), but the transmittance gradually decreases as the frequency increases. I understand.

  From these facts, it was found that a low-frequency component in the terahertz band passes through the packaging surface of the drug container 20 and the encapsulated powder, so that there is a possibility that foreign matter mixed in the powder can be detected. .

<Configuration of Foreign Object Detection Device 10>
FIG. 2 is an overview of the foreign object detection device 10 according to an embodiment of the present invention. FIG. 3 is a schematic explanatory diagram showing the principle of foreign object detection in the foreign object detection device 10. 4A is a visible image of the measurement sample, FIG. 4B is a terahertz wave reflection image, FIG. 4C is a tomographic image along the solid line in FIG. 4B, and FIG. 4D is a frequency. It is an image which illustrates an image, respectively. FIG. 5 is an explanatory diagram of a conversion process from a time-resolved mapping image to an intensity mapping image by Fourier transform. FIG. 6 is a graph illustrating a signal (time waveform signal) output in time series. FIG. 7 is a graph illustrating a power spectrum obtained by Fourier transform from a signal (time waveform signal) output in time series.

  As shown in FIG. 2, the foreign object detection apparatus 10 includes an oscillator 11 that generates a terahertz pulse wave and irradiation light L <b> 1 of the terahertz pulse wave that is generated from the oscillator 11 to the upper surface of a measurement sample such as a drug container 20. An optical system 12 that condenses the reflected light L2 reflected from the measurement sample, a receiver 13 that outputs an electric signal corresponding to the reflected light L2 collected by the optical system 12, and a terahertz pulse by the optical system 12. A scanning mechanism 14 (detailed structure and the like is not shown) that two-dimensionally scans the position of the measurement sample upper surface to which the wave irradiation light L1 is guided, and a reflection image and a tomographic image obtained from an electrical signal output from the receiver 13 And a calculation unit 15 that detects the presence and type of the foreign substance 21 in the powder sealed in the medicine container 20 based on at least one of the frequency images, and an oscillator 11, Shin 13, and a control unit 16 for controlling the whole, such as the scanning mechanism 14 and the arithmetic unit 15.

  The oscillator 11 generates a terahertz pulse wave including a frequency of 0.1 to 10 THz, and refracts the terahertz pulse wave by the hemispherical lens 11a provided in the generation direction of the terahertz pulse wave.

  The optical system 12 collects the terahertz pulse wave that is generated by the oscillator 11 and reflects the terahertz pulse wave refracted by the hemispherical lens 11a and changes the direction downward, and the terahertz pulse wave that is changed in direction by the half mirror 12a. A convex lens 12b that guides the irradiated irradiation light L1 to the measurement sample and refracts the reflected light L2 from the measurement sample is provided.

  Here, as shown in FIG. 3, the irradiation light L1 from the oscillator 11 passes through the resin sheet on the surface 20a of the medicine container 20 almost as it is (a part is reflected slightly and becomes a part of the reflected light L2). ). The transmitted irradiation light L1 is partially reflected on the surface of the foreign material 21 (the reflected light later passes through the surface 20a and becomes a part of the reflected light L2), and another part is absorbed by the foreign material 21, The remainder passes through while being diffracted by the foreign matter 21. The remaining irradiation light L1 thus transmitted is reflected by the aluminum sheet on the back surface 20b of the medicine container 20, further passes through the foreign material 21, and also passes through the front surface 20a to become a part of the reflected light L2.

  The receiver 13 condenses the reflected light L2 refracted by the convex lens 12b and transmitted through the half mirror 12a by the hemispherical lens 13a provided in the arrival direction, and the electricity according to the intensity of the collected reflected light L2. Output a signal.

  The scanning mechanism 14 moves the oscillator 11, the optical system 12, and the entire receiver 13 in the X direction and the Y direction orthogonal to each other along the plane on which the measurement sample is placed while the position of the measurement sample is fixed. The measurement sample is configured to be scanned two-dimensionally. However, it is not always necessary to move the oscillator 11, the optical system 12, and the entire receiver 13. Conversely, the measurement sample may be moved in the X direction and the Y direction while the positions of the oscillator 11, the optical system 12, and the receiver 13 are fixed.

  Further, instead of such movement, if scanning is performed by periodic driving (for example, shaking a mirror) of at least a part of the optical system 12, scanning at higher speed becomes possible. In this case, it is preferable to use a telecentric optical system.

  For example, an electrical signal from the receiver 13 corresponding to the reflected light L2 is acquired in time series while scanning a range in which a powder such as a drug is present in the measurement sample in two dimensions at intervals of 1 mm or less.

  The arithmetic unit 15 calculates a value obtained by time-integrating the absolute value of an electric signal (time waveform signal, for example, see FIG. 6) acquired in time series from the receiver 13 during two-dimensional scanning by the scanning mechanism 14 for each pixel value. A terahertz wave reflection image (see, for example, FIG. 4B) is obtained.

  In addition, by measuring the echo of the terahertz pulse wave, a tomographic image along a straight line connecting any two points at the end of the reflection image (see, for example, FIG. 4C) is obtained as necessary. Can be calculated.

  Further, a power spectrum is obtained by performing Fourier transform on a time image acquired in time series at intervals of a period required for two-dimensional scanning, that is, a time-resolved mapping image (time waveform: I (X, Y, t)). (See, for example, FIG. 7) and an intensity mapping image. An arbitrary frequency image (see, for example, FIG. 4D) can be extracted from the intensity mapping image.

  Then, by appropriately combining at least one or more of the time waveform signal thus obtained (value corresponding to), the reflection image, the power spectrum, the tomographic image, and the frequency image as necessary, It becomes possible to detect foreign matter contained in the powder.

<Example of measurement image>
(1) Metallic foreign matter FIG. 8A is a visible image showing a drug container containing a powder containing the metallic foreign matter and a measurement area, FIG. 8B is a terahertz wave reflection image, and FIGS. (G) is an image which illustrates the tomographic image along each solid line in FIG.8 (b), respectively.

  As shown in these images, the metal foreign object reflects the terahertz wave and can be detected by the foreign object detection device 10.

(2) Resin foreign matter: polystyrene FIG. 9A is a visible image showing a drug container containing a powder containing the resin foreign matter, FIG. 9B is a terahertz wave reflection image, and FIGS. e) is an image illustrating the tomographic image along each solid line in FIG. 9B.

  As shown in these images, the resin foreign matter can be detected by the foreign matter detection device 10 because the transmittance with respect to the terahertz wave is different from that of the drug container or the powder.

(3) Resin foreign matter: silicon rubber FIG. 10A is a visible image showing a drug container containing a powder containing the resin foreign matter, FIG. 10B is a terahertz wave reflection image, and FIGS. (E) is an image which illustrates the tomographic image along each solid line in FIG.10 (b), respectively.

  As shown in these images, the resin foreign matter can be detected by the foreign matter detection device 10 because the transmittance with respect to the terahertz wave is different from that of the drug container or the powder.

(4) Carbonized drug FIG. 11 (a) is a visible image showing a drug container containing a powder containing the carbonized drug, FIG. 11 (b) is a terahertz wave reflection image, and FIGS. 11 (c) and 11 (d). These are images illustrating the tomographic images along the solid lines in FIG.

  As shown in these images, the carbonized drug has a transmittance for terahertz waves that is different from that of the drug container or powder, and therefore can be detected by the foreign substance detection device 10.

(5) Hair in Lactose FIG. 12 (a) is a visible image showing the arrangement of the hair, FIG. 12 (b) is a visible image in which the top is covered with 3 mm of lactose, and FIG. 12 (c) is terahertz. Wave reflection images, FIG. 12D are images illustrating frequency images (0.62 THz), respectively.

  13A is the same terahertz wave reflection image as FIG. 12C, FIG. 13B is an AA ′ tomographic image of FIG. 13A, and FIG. 13C is FIG. 13A. It is an image which respectively illustrates BB 'tomographic image of.

  14 (a) is the same visible image as FIG. 12 (b), FIG. 14 (b) is the same terahertz wave reflection image as FIG. 12 (c) and FIG. 13 (a), and FIGS. 13 (c) to 13 (i). ) Is an image illustrating each frequency image obtained by changing the frequency of the terahertz wave in the range of 0.1 to 0.8 THz.

  As shown in these images, the hair covered with lactose is of course not visible in the visible image of FIG. 12 (b), but the hair (point of the arrow) is of a certain degree in the terahertz wave reflection image of FIG. 12 (c). Is visible. In addition, it is thought that what is circular in the area surrounded by a broken line is a solidified lactose. The frequency image in FIG. 12 (d) is the result of selecting FIG. 14 (h) where the hair appears to be most vivid from among FIGS. 14 (c) to 14 (i). Can be identified.

  Thus, the hair in lactose can be detected based on the terahertz wave reflection image, the tomographic image, and the frequency image, and the optimum value of the frequency of the terahertz wave in this case is 0.62 THz.

  According to the configuration of the present embodiment described above, the time waveform signal, terahertz, even if the foreign substance 21 in the powder such as lactose enclosed in the drug container 20 is not only metal or resin but also hair. By combining one or more of a wave reflection image, a tomographic image, a power spectrum, and a frequency image with appropriately set frequencies, it is possible to accurately detect to a considerable degree of accuracy.

<Other embodiments>
In the above-described embodiment, the foreign substance detection device 10 suitable for detecting foreign substances contained in the powder in the medicine container 20 has been described, but the present invention is not limited to such a configuration. For example, even if powder that may contain foreign substances is not stored in various drug containers, the powder is irradiated with terahertz pulse waves, and the transmitted light that has passed through the powder or the reflection that has been reflected from the powder Either one or both of the light may be used.

  Then, by combining one or more of the time waveform signal, the terahertz wave reflection image, the tomographic image, the power spectrum, and the frequency image in which the frequency is appropriately set, it becomes possible to detect the foreign matter contained in the powder in the same manner.

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-mentioned embodiment is only a mere illustration in all points, and should not be interpreted limitedly. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Foreign object detection apparatus 11 Oscillator 11a Hemispherical lens 12 Optical system 12a Half mirror 12b Convex lens 13 Receiver 13a Hemispherical lens 14 Scanning mechanism 15 Control part 16 Control unit 20 Drug container 20a Surface 20b Back surface 21 Foreign substance 22 Hair L1 Irradiation light L2 Reflected light

Claims (1)

A foreign matter detection method for detecting foreign matter in powder,
An oscillation process for generating terahertz pulse waves and emitting them as irradiation light;
The irradiation light emitted in this oscillation step is guided to the powder and the reflected light reflected from the powder and / or the transmitted light transmitted through the powder is collected, and the reflected light thus collected and And / or a receiving step of outputting a signal corresponding to the transmitted light;
A scanning step of scanning a position on the powder to which the irradiation light is guided;
A value corresponding to the time waveform signal output in time series from the receiving step, a reflection image having each pixel value as a value obtained by time integration of the time waveform signal, and a power spectrum calculated by Fourier transform of the time waveform signal And a calculation step of detecting foreign matter in the powder based on at least one of frequency images in which each pixel value is a value calculated by Fourier transform of the time waveform signal,
The powder is a drug containing a pharmaceutically active substance,
The frequency of the terahertz pulse wave is 1 THz or less.