CN110794448A - Device and method for measuring X-ray energy - Google Patents
Device and method for measuring X-ray energy Download PDFInfo
- Publication number
- CN110794448A CN110794448A CN201911197922.5A CN201911197922A CN110794448A CN 110794448 A CN110794448 A CN 110794448A CN 201911197922 A CN201911197922 A CN 201911197922A CN 110794448 A CN110794448 A CN 110794448A
- Authority
- CN
- China
- Prior art keywords
- metal filter
- support plate
- metal
- energy
- screen box
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/36—Measuring spectral distribution of X-rays or of nuclear radiation spectrometry
Abstract
The invention provides a device and a method for measuring X-ray energy by using a metal filter disc. The method provided by the invention adopts a modular design scheme, is very favorable for disassembly and assembly, and can be conveniently used for measuring the X-ray energy. By using the combination mode of different types and thicknesses of filter discs, the accurate measurement of the number of X-ray photons in an energy band of 0-90 keV can be realized, and the accurate calculation of the X-ray in a large energy range of 0-300 keV can be performed.
Description
Technical Field
The invention belongs to the field of X-ray energy measurement, and particularly relates to a device and a method for measuring X-ray energy.
Background
X-rays were discovered in 1895 by the german physicist w.k. roentgen and are also referred to as roentgen rays. The wavelength of the electromagnetic wave is between 0.01 and 100 angstroms, and the electromagnetic wave is an electromagnetic wave between ultraviolet rays and gamma rays. Due to its short wavelength, it has high energy and high penetrating power, and can transmit many substances opaque to visible light, such as wood board and plastic. However, because X-rays have high energy, it can be used in various fields such as scientific detection, biological imaging, medical treatment, etc., for example, CT, which is a Computed Tomography (CT) technique commonly used in hospitals, scans a certain part of a human body with a precisely collimated X-ray beam, and diagnoses diseases through imaging. However, the X-ray physical properties of the individual energy segments are very different and their penetration capabilities are also very different. Therefore, we should understand the energy of the X-ray before design and use and measure it.
At present, an X-ray single photon counter (X-ray CCD) is generally used for detecting X-ray energy, and the method is simple and easy to implement, has high sensitivity and can quickly give the energy spectrum distribution of the X-ray. However, the X-ray CCD can only detect the photon energy with lower energy, and cannot detect the photon energy with higher energy. And the X-ray CCD also has requirements on the brightness of X-rays, and the crystal in the CCD is directly damaged when the brightness is too high. X-ray energy can be measured using metal filter sheets of different thicknesses and materials. For example, by using different metals to absorb X-rays K-edge, two by one, the X-ray energy spectrum of the low energy band can be accurately measured, and the X-ray energy spectrum is the so-called Ross-filter. But this approach also fails to measure X-rays below the energy of 30 keV. If higher-energy X-rays are to be measured, filters of different types and thicknesses need to be replaced, but no filter which is combined in a centering mode is available at present, so that the calculation statistics of the number of photons of the generated round light spots can have larger errors, and the measurement can only be used as a relatively rough measurement.
Disclosure of Invention
Accordingly, it is an object of the present invention to overcome the disadvantages of the prior art and to provide an apparatus and method for measuring X-ray energy.
Before the technical solution of the present invention is explained, the terms used herein are defined as follows:
the term "IP" refers to: imaging Plate.
The invention aims to overcome the defects in the prior art, 10 metal filter discs are placed in a centering mode, and the combination mode of different types and thicknesses of filter discs is utilized, so that the accurate measurement of the number of X-ray photons in an energy band of 0-90 keV can be realized, and the accurate calculation of X-rays in a large energy range of 0-300 keV can be realized.
To achieve the above object, a first aspect of the present invention provides an apparatus for measuring X-ray energy, the apparatus comprising: the device comprises a lead screen box, an IP supporting plate, a metal filter sheet supporting plate and one or more groups of metal filter sheets, wherein every two of the metal filter sheets are in one group;
preferably, the device has 2-10 groups of metal filter discs, preferably 5-7 groups of metal filter discs;
and when the device is provided with a plurality of groups of metal filter sheets, the plurality of groups of filter sheets are stacked and arranged on the metal filter sheet supporting plate.
The device according to the first aspect of the present invention, wherein the material of the metal filter sheet is selected from transition metals or third and fourth main group metal elements;
preferably, the transition metal or third and fourth main group metal elements are one or more of the following: ga. Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb, Au, W; and/or
Preferably, the metal filter sheet is triangular, and more preferably is an isosceles triangle with the bottom having the small holes on the central line of the bottom. The thickness of the whole filter disc is uniformly distributed, and the top angle of the filter disc is 25-40 degrees, preferably 30-40 degrees, and most preferably 36 degrees.
The apparatus according to the first aspect of the present invention, wherein when the material of the metal filter is selected from: ga. One or more of Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb and Au, the thickness of the alloy is 1-300 μm, preferably 5-150 μm; and/or
When the material of the metal filter sheet is selected from: when one or more of Al, Ta, Cu and W are used, the thickness is 0.1 to 10mm, preferably 0.1 to 8 mm.
The device according to the first aspect of the invention, wherein the lead screen box is made of lead, two side surfaces of the lead screen box are correspondingly provided with grooves, and the upper side and the bottom surface of the lead screen box are correspondingly provided with small holes; preferably, the thickness of each surface of the lead screen box is 1-5 cm, more preferably 1-3 cm, and most preferably 2 cm.
According to the device of the first aspect of the invention, the IP support plate ridge is inserted from the vertical direction close to the rear side of the lead screen box, the protrusion of the IP support plate and the groove on the side surface of the lead screen box are embedded together, and the IP is inserted into the IP support plate gap from the upper side and is leaned against the IP support plate ridge.
Preferably, the metal filter support plate is provided with front threaded holes and side threaded holes which are uniformly distributed, and the side threaded holes are used for fixing the metal filter support plate on the small holes of the lead screen box.
Preferably, the small holes at the bottom of the metal filter disc are used for fixing the metal filter disc on the threaded holes in the front face of the metal filter disc supporting plate.
A second aspect of the invention provides a method of measuring X-ray energy using a metal filter, the method comprising using the apparatus of the first aspect to make a measurement of X-ray energy.
According to the method of the second aspect of the invention, when the detected photon energy is less than 90keV, the material of the metal filter is selected from one or more of the following: ga. Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb and Au; the thickness of the metal filter sheet is 1-300 μm, preferably 5-150 μm.
According to the method of the second aspect of the invention, when the detected photon energy is within 0-300 keV, the material of the metal filter is selected from one or more of the following materials: al, Ta, Cu, W; the thickness of the metal filter disc is 0.1-10 mm, and preferably 0.1-8 mm.
The device and the method for measuring the X-ray energy by using the metal filter disc have the following beneficial effects that:
1. the modular design is very convenient for disassembly and assembly, and can be conveniently used for measuring the X-ray energy.
2. By using the combination mode of different types and thicknesses of filter discs, the accurate measurement of the number of X-ray photons in an energy band of 0-90 keV can be realized, and the accurate calculation of the X-ray in a large energy range of 0-300 keV can be performed.
Drawings
Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:
fig. 1 shows a perspective view of a lead screen box provided in embodiment 1 of the present invention;
FIG. 2 is a perspective view showing an IP (imaging plate) support plate according to embodiment 1 of the present invention;
fig. 3 shows a perspective view of a metal filter support plate of embodiment 1 of the present invention;
fig. 4 shows a perspective view of the front surface of a metal filter sheet of embodiment 1 of the present invention.
FIG. 5 shows the photon energy vs. transmittance of Table 1 of example 2.
FIG. 6 shows the photon energy vs. transmittance of Table 2 of example 2.
Description of reference numerals:
1. the upper side of the lead screen box; 2. the rear side of the lead screen box; 3. the side surface of the lead screen box; 4. a small hole; 5. a groove; 6. a lead screen box base; 7. an IP support plate protrusion; 8. an IP support plate backbone; 9. an IP support plate gap; 10. a metal filter support plate; 11. the front threaded hole of the metal filter supporting plate; 12. the side surface of the metal filter supporting plate is provided with a threaded hole; 13. a metal filter disc; 14. and small holes of the metal filter disc.
Detailed Description
The invention is further illustrated by the following specific examples, which, however, are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
This section generally describes the materials used in the testing of the present invention, as well as the testing methods. Although many materials and methods of operation are known in the art for the purpose of carrying out the invention, the invention is nevertheless described herein in as detail as possible. It will be apparent to those skilled in the art that the materials and methods of operation used in the present invention are well within the skill of the art, provided that they are not specifically illustrated.
The materials used in the following examples are as follows:
ga. Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb, Au, W, 5cm x 5cm high purity metal pieces purchased from North China science and technology metal materials.
Example 1
This embodiment is intended to explain the specific structure of the apparatus of the present invention.
Fig. 1 is a perspective view of a lead screen box of the device of the present invention, in order to prevent the external high-energy ray background from affecting the reading of ip (imaging plate), the upper side (1) of the lead screen box, the rear side (2) of the lead screen box, the side (3) of the lead screen box and the base (6) of the lead screen box are all made of lead, have a thickness of 2cm, and can shield X-rays with energy below 600 keV.
Fig. 2 is a perspective view of the IP support plate of the device of the present invention, wherein the IP support plate ridge (8) is inserted from the vertical direction against the rear side (2) of the lead screen box, the IP support plate protrusion (7) and the groove (5) are embedded together, and the IP is inserted into the IP support plate gap (9) from above and is against the IP support plate ridge (8) during implementation.
Fig. 3 is a perspective view of a metal filter support plate of the device of the present invention, wherein the metal filter support plate (10) is used as a support block of a metal filter, 10 uniformly distributed metal filter support plate front threaded holes (11) are punched on the metal filter support plate, and four metal filter support plate side threaded holes (12) are distributed around the metal filter support plate (10) for fixing the metal filter support plate (10) on the small holes (4) of the lead screen box.
Fig. 4 is a perspective view of the front surface of the metal filter of the device of the present invention, the selection of the metal filter (13) is very critical, and the photon number of each energy segment can be calculated more accurately by the proper metal filter. The metal filter sheet small holes (14) are used for fixing 10 metal filter sheets on the threaded holes (11) in the front of the metal filter sheet supporting plate.
Example 2
This example serves to illustrate a specific method of use of the device of the present invention.
10 metal filter sheets were made in the shape shown in fig. 4, the apex angle was 36 °, the metal filter sheets were related to the choice of material and thickness, two groups of metal filter sheets were chosen as follows:
table 1 protocol-selection of metal filter material and thickness
The relationship between photon energy and transmittance is shown in fig. 5.
Table 2 scheme two metal filter material and thickness selection
The relationship between photon energy and transmittance is shown in fig. 6.
The key to the implementation of the method is that the X-ray light spot is required to be circular, and the circle formed by the light spot and the metal filter is centered, so that the photon yield of the X-ray can be accurately calculated.
The photon energy spectrum calculation formula is as follows:
wherein Δ S ═ Sk-Sk+1Represents the difference in PSL across the two filter sheets,
representing the difference of the X-ray transmittances of two filter sheets in a certain energy band,
represents the response of the IP to photons, and
representing the number of photons per unit energy.
The difference delta S between PSL is obtained by subtracting the filter 1 and the filter 2 on the IP imaging plate, the difference delta T between the transmittances of the two filters to a certain energy band can be obtained by calculation, and the response of IP to photons
Can be obtained by looking up the data. Thus, according to equation (1), the average photon number density per unit energy is:
finally, the total number of photons is obtained by adding the energy segments:
where Δ E represents the width of the individual photon energy bins.
The method for measuring the X-ray energy by using the metal filter disc adopts a combination mode of two materials, and needs to predict the energy range of the X-ray according to a theory and select a proper combination mode of the metal filter disc. If the detected photon energy is within 90keV, the first scheme is adopted, and then 5 suitable pairs are selected according to the photon energy range of X-ray to be detected, which is shown in Table 1. The metal filter sheets are sequentially fixed on a support plate (10) and are placed in a centering mode, two metal filter sheets of the filter sheet 1 and the filter sheet 2 in the form are combined in the same pair, and the arrangement sequence of the metal filter sheets in each group is random. It should be noted that if filter 1 or 2 contains multiple filters, they need to be stacked for use. If necessary, the number of the metal filter pieces can be increased to 7 pairs, and the top angle of the metal filter pieces is changed correspondingly. Since the difference Δ T in the transmittance of photons in this energy band is steep on both sides, the out-of-range cutoff, see FIG. 5, allows the total number of photons in 90keV to be accurately obtained according to equations (2) and (3).
And if the energy range of the photons needing to be detected is larger and is within 0-300 keV, and the calculation of the number of the photons requires less accurate measurement, adopting a second scheme, and showing in a table 2. The difference between the two schemes is that the difference Δ T between the transmittances of photons in the energy band has no cutoff range, so the full width at half maximum of Δ T needs to be calculated, as shown in fig. 6. Response to photons of difference between energy transmission rates Δ T and IP in the full width half maximum energy band
The total number of photons can be calculated more accurately by integrating, then estimating the average photon number density according to equation (2), and finally summing, according to equation (3).
Although the present invention has been described to a certain extent, it is apparent that appropriate changes in the respective conditions may be made without departing from the spirit and scope of the present invention. It is to be understood that the invention is not limited to the described embodiments, but is to be accorded the scope consistent with the claims, including equivalents of each element described.
Claims (10)
1. An apparatus for measuring X-ray energy, the apparatus comprising: the device comprises a lead screen box, an IP supporting plate, a metal filter sheet supporting plate and one or more groups of metal filter sheets, wherein every two of the metal filter sheets are in one group;
preferably, the device has 2-10 groups of metal filter discs, preferably 5-7 groups of metal filter discs;
and when the device is provided with a plurality of groups of metal filter sheets, the plurality of groups of filter sheets are stacked and arranged on the metal filter sheet supporting plate.
2. The apparatus of claim 1, wherein the metal filter is made of a material selected from transition metals or third and fourth main group metal elements;
preferably, the transition metal or third and fourth main group metal elements are one or more of the following: ga. Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb, Au, W; and/or
Preferably, the metal filter sheet is triangular, and more preferably is an isosceles triangle with the bottom having the small holes on the central line of the bottom. The thickness of the whole filter disc is uniformly distributed, and the top angle of the filter disc is 25-40 degrees, preferably 30-40 degrees, and most preferably 36 degrees.
3. The apparatus of claim 1 or 2, wherein when the metal filter is made of a material selected from the group consisting of: ga. One or more of Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb and Au, the thickness of the alloy is 1-300 μm, preferably 5-150 μm; and/or
When the material of the metal filter sheet is selected from: when one or more of Al, Ta, Cu and W are used, the thickness is 0.1 to 10mm, preferably 0.1 to 8 mm.
4. The device according to any one of claims 1 to 3, wherein the lead screen box is made of lead, the two side surfaces of the lead screen box are correspondingly provided with grooves, and the upper side and the bottom surface of the lead screen box are correspondingly provided with small holes; preferably, the thickness of each surface of the lead screen box is 1-5 cm, more preferably 1-3 cm, and most preferably 2 cm.
5. The apparatus of any one of claims 1 to 4, wherein the IP support plate ridge is inserted from the vertical direction against the rear side of the lead case, the protrusion of the IP support plate and the groove of the side of the lead case are embedded with each other, and the IP is inserted into the IP support plate slot from above and abuts against the IP support plate ridge.
6. The device of any one of claims 1 to 5, wherein the metal filter support plate has uniformly distributed front threaded holes and side threaded holes for fixing the metal filter support plate on the small holes of the lead screen box.
7. The apparatus of any one of claims 1 to 6, wherein the metal filter bottom aperture is used to secure the metal filter to the metal filter support plate front threaded hole.
8. A method of measuring X-ray energy using a metal filter, the method comprising using the apparatus of any one of claims 1 to 7 to make a measurement of X-ray energy.
9. The method of claim 8, wherein when the detected photon energy is less than 90keV, the material of the metal filter is selected from one or more of: ga. Ti, Al, Mo, Sn, Dy, Cu, Ta, Pb and Au; the thickness of the metal filter sheet is 1-300 μm, preferably 5-150 μm.
10. The method of claim 7, wherein the metal filter is made of a material selected from one or more of the following materials when the detected photon energy is within 0-300 keV: al, Ta, Cu, W; the thickness of the metal filter disc is 0.1-10 mm, and preferably 0.1-8 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911197922.5A CN110794448B (en) | 2019-11-29 | 2019-11-29 | Device and method for measuring X-ray energy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911197922.5A CN110794448B (en) | 2019-11-29 | 2019-11-29 | Device and method for measuring X-ray energy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110794448A true CN110794448A (en) | 2020-02-14 |
| CN110794448B CN110794448B (en) | 2021-12-03 |
Family
ID=69446741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911197922.5A Active CN110794448B (en) | 2019-11-29 | 2019-11-29 | Device and method for measuring X-ray energy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110794448B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101254108A (en) * | 2007-03-02 | 2008-09-03 | 通用电气公司 | Light firm digital X ray detector |
| CN102621167A (en) * | 2012-03-19 | 2012-08-01 | 中国科学院物理研究所 | Transmission-type hard X-ray spectrometer |
| US20140264083A1 (en) * | 2013-03-15 | 2014-09-18 | Babcock & Wilcox Technical Services Y-12, L.L.C. | Computed radiography imaging plates and associated methods of manufacture |
| CN104065889A (en) * | 2014-06-25 | 2014-09-24 | 山东大学 | Pseudo dual energy X-ray line array imaging system |
| CN104634799A (en) * | 2013-11-15 | 2015-05-20 | 郑琪 | Device and method for measuring multi-wavelength characteristic X ray diffraction |
| CN206725471U (en) * | 2017-05-12 | 2017-12-08 | 中国工程物理研究院激光聚变研究中心 | A kind of quantitatively calibrating system of X-ray imaging plate |
| CN109041393A (en) * | 2018-06-26 | 2018-12-18 | 中国科学院物理研究所 | A kind of generation device and method in ultrafast hard X ray source |
| CN109164120A (en) * | 2018-08-22 | 2019-01-08 | 中国工程物理研究院激光聚变研究中心 | A kind of high time resolution SOFT X-RAY SPECTROMETER |
| CN110308614A (en) * | 2018-03-20 | 2019-10-08 | 中国科学院物理研究所 | The method and apparatus of X-ray intensity relevance imaging |
-
2019
- 2019-11-29 CN CN201911197922.5A patent/CN110794448B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101254108A (en) * | 2007-03-02 | 2008-09-03 | 通用电气公司 | Light firm digital X ray detector |
| CN102621167A (en) * | 2012-03-19 | 2012-08-01 | 中国科学院物理研究所 | Transmission-type hard X-ray spectrometer |
| US20140264083A1 (en) * | 2013-03-15 | 2014-09-18 | Babcock & Wilcox Technical Services Y-12, L.L.C. | Computed radiography imaging plates and associated methods of manufacture |
| CN104634799A (en) * | 2013-11-15 | 2015-05-20 | 郑琪 | Device and method for measuring multi-wavelength characteristic X ray diffraction |
| CN104065889A (en) * | 2014-06-25 | 2014-09-24 | 山东大学 | Pseudo dual energy X-ray line array imaging system |
| CN206725471U (en) * | 2017-05-12 | 2017-12-08 | 中国工程物理研究院激光聚变研究中心 | A kind of quantitatively calibrating system of X-ray imaging plate |
| CN110308614A (en) * | 2018-03-20 | 2019-10-08 | 中国科学院物理研究所 | The method and apparatus of X-ray intensity relevance imaging |
| CN109041393A (en) * | 2018-06-26 | 2018-12-18 | 中国科学院物理研究所 | A kind of generation device and method in ultrafast hard X ray source |
| CN109164120A (en) * | 2018-08-22 | 2019-01-08 | 中国工程物理研究院激光聚变研究中心 | A kind of high time resolution SOFT X-RAY SPECTROMETER |
Non-Patent Citations (1)
| Title |
|---|
| 陈盘训: "不同金属材料对不同能量X射线衰减系数的实验测量", 《第八届全国抗辐射电子学与电磁脉冲学术交流会》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110794448B (en) | 2021-12-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Koenig et al. | How spectroscopic x-ray imaging benefits from inter-pixel communication | |
| Amaldi et al. | Construction, test and operation of a proton range radiography system | |
| Ren et al. | Effects of reflector and crystal surface on the performance of a depth‐encoding PET detector with dual‐ended readout | |
| Tanguay et al. | The role of x‐ray Swank factor in energy‐resolving photon‐counting imaging | |
| Weinmann et al. | Design of optimal collimation for dedicated molecular breast imaging systems | |
| JP2008510131A (en) | Arrangement of scintillator and anti-scatter grid | |
| Kirby et al. | Developments in electronic portal imaging systems | |
| Johnson et al. | Characterization of a high-purity germanium detector for small-animal SPECT | |
| WO2001027656A1 (en) | Method and arrangement relating to x-ray imaging | |
| Salvagnini et al. | Effective detective quantum efficiency for two mammography systems: measurement and comparison against established metrics | |
| US20080157255A1 (en) | Semiconductor radiation detector and radiation detection equipment | |
| Santos et al. | Direct measurement of clinical mammographic x‐ray spectra using a CdTe spectrometer | |
| Duisterwinkel et al. | Spectra of clinical CT scanners using a portable Compton spectrometer | |
| Zhang et al. | X‐ray spectral measurements for tungsten‐anode from 20 to 49 kVp on a digital breast tomosynthesis system | |
| Wang et al. | High‐DQE EPIDs based on thick, segmented BGO and CsI: Tl scintillators: performance evaluation at extremely low dose | |
| Ji et al. | Anomalous edge response of cadmium telluride-based photon counting detectors jointly caused by high-flux radiation and inter-pixel communication | |
| Levin et al. | PSPMT and photodiode designs of a small scintillation camera for imaging malignant breast tumors | |
| JP2001507453A (en) | Detection head and collimator for gamma camera | |
| CN110794448B (en) | Device and method for measuring X-ray energy | |
| Hemdal et al. | Average glandular dose in routine mammography screening using a Sectra MicroDose Mammography unit | |
| Stumbo et al. | Direct analysis of molybdenum target generated x‐ray spectra with a portable device | |
| Monnin et al. | An image quality comparison of standard and dual‐side read CR systems for paediatric radiology | |
| Wunderle et al. | Effect of fluoroscopic X‐ray beam spectrum on air‐kerma measurement accuracy: implications for establishing correction coefficients on interventional fluoroscopes with KAP meters | |
| Amendolia et al. | Characterization of a mammographic system based on single photon counting pixel arrays coupled to GaAs x‐ray detectors | |
| Martišíková et al. | Characterization of a flat-panel detector for ion beam spot measurements |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |