CN107121652B - For the multifrequency point array RF receiving coil system in MR imaging apparatus - Google Patents
For the multifrequency point array RF receiving coil system in MR imaging apparatus Download PDFInfo
- Publication number
- CN107121652B CN107121652B CN201710326299.3A CN201710326299A CN107121652B CN 107121652 B CN107121652 B CN 107121652B CN 201710326299 A CN201710326299 A CN 201710326299A CN 107121652 B CN107121652 B CN 107121652B
- Authority
- CN
- China
- Prior art keywords
- frequency
- circuit
- tuning
- coil
- single channel
- 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.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
- G01R33/36—Electrical details, e.g. matching or coupling of the coil to the receiver
- G01R33/3628—Tuning/matching of the transmit/receive coil
- G01R33/3635—Multi-frequency operation
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
The invention discloses a kind of multifrequency point array RF receiving coil system in MR imaging apparatus, coil system is mainly made of N number of single channel planar coil module；Each single channel planar coil module includes: single channel planar coil, M tuning and match circuit, frequency handover circuit and pre-amplification circuit；The present invention can be realized the function of radio-frequency coil multifrequency point work, so as to realize quick, the stable switching between multifrequency point on the same coil, so that can be realized multiple nuclear imagings on same nuclear magnetic resonance equipment, and then the operability of the purposes for the equipment widened, the cost for reducing equipment, raising equipment.
Description
Technical field
The invention belongs to field of magnetic resonance imagings, specifically devise a kind of multifrequency point array RF receiving coil system,
The coil is applied in open MRI equipment.
Background technique
Magnetic resonance imaging (MRI) is a kind of medical imaging devices being widely used at present.In general, open type magnetic is total
The structure of vibration imaging device can be divided into magnet system, spectrometer system and image display system three parts.Wherein, magnet system
It is very important core, it is made of main magnet, gradient coil, shim coil and radio-frequency coil.
In clinical MRI scanner, radio-frequency coil is in the front end for receiving MRI signal, radio-frequency coil quality it is excellent
The bad intensity for directly determining MRI signal, there are two the major functions of radio-frequency coil, one is excitation nuclear spin, the second is detection
Core precession.In excitation mode work, as a converter, it is transformed to radio-frequency power the transverse rotation in imaging volume
RF magnetic field B1, the direction in the magnetic field and the direction B0 of magnetostatic field are vertical；In reception pattern work, radio-frequency coil is precession
Transverse magnetisation M be converted to suitable for processing voltage signal.For designing good radio-frequency coil, penetrated in imaging region
Frequency field B1 should be uniform, and radio-frequency coil should have high s/n ratio.
Traditional radio-frequency coil is designed for a certain specific nuclear Larmor precession frequency to design
, it is merely able to carry out a kind of imaging of atom；For multiple nuclear imagings, the radio-frequency coil usually more renewed is either
Again coil is tuned and is matched.Not only cost of idleness, but also need professional equipment and specialized work personnel and come
Corresponding operation is carried out, this is very inconvenient for actual application.
Summary of the invention
The present invention is proposed a kind of for MR imaging apparatus to solve above-mentioned the shortcomings of the prior art place
In multifrequency point array RF receiving coil system, to be able to achieve radio-frequency coil multifrequency point work function, so as to
Quick, the stable switching between multifrequency point is realized on the same coil, so that can be realized on same nuclear magnetic resonance equipment more
A nuclear imaging, and then the operability of the purposes for the equipment widened, the cost for reducing equipment, raising equipment.
The present invention adopts the following technical scheme that in order to solve the technical problem
A kind of the characteristics of multifrequency point array RF receiving coil system in MR imaging apparatus of the present invention is
It is made of N number of single channel planar coil module；Each single channel planar coil module includes: single channel planar coil, M tuning
With match circuit, frequency handover circuit and pre-amplification circuit；
The single channel planar coil is separately connected the M tuning and match circuit；The M tuning and match circuit
It is connect with the pre-amplification circuit；The frequency handover circuit be connected on the single channel planar coil and M tuning with
With between circuit；Tuning and match circuit are made of tuning capacitance and matching capacitance；
The single channel planar coil module detects quilt in MR imaging apparatus using the single channel planar coil
After surveying the NMR signal of body, select the M tuning is corresponding with match circuit to adjust by the frequency handover circuit
It is humorous to be linked into the single channel planar coil with match circuit so that the NMR signal by selected tuning with
Match circuit, which is transmitted in the pre-amplification circuit, carries out decoupling and enhanced processing, thus the nuclear magnetic resonance letter that obtains that treated
Number.
The frequency handover circuit includes: direct current driving power supply, knob switching switch, M radio-frequency choke, M are a opens
Close PIN diode pair and M ground connection PIN diode pair；
The knob switching switch is provided with M gear, and each gear respectively corresponds different working frequency points；Each shelves
The radio-frequency choke is correspondingly provided on position；The radio-frequency choke and corresponding switch PIN diode are to being connected；It is described
Switch PIN diode pair and corresponding ground connection PIN diode are to being connected；The ground connection PIN diode is to position therebetween
Take out line ground connection in place；
The frequency handover circuit is to utilize working frequency points needed for knob switching switch selection, the DC driven electricity
Switch PIN diode pair and ground connection PIN diode pair is connected by the radio-frequency choke on relevant work frequency point in source, to make
It obtains tuning corresponding with required working frequency points to be linked into the single channel planar coil with match circuit, realizes multifrequency point
Between switching.
Compared with prior art, the beneficial effects of the present invention are:
1, radio-frequency coil has M working frequency points in the present invention, correspondingly devises M tuning and match circuit, corresponds to M
A nuclear magnetic resonance imaging, and be linked between resonance matching circuit and coil by switch switching circuit, selection is corresponding
Tuning and match circuit, adjust the resonance frequency point of coil so that the same coil switches between multiple working frequency points, thus
Meet multiple nuclear magnetic resonance imagings in conventional magnetic resonance equipment.
2, the switch switching circuit that the present invention designs, the on-off of circuit is realized using PIN pipe as electric switch,
The characteristic of PIN pipe is just equivalent to a switch, and in an off state when reverse-biased, positively biased Shi Zewei opening state is designed with PIN pipe
RF switch can control powerful radiofrequency signal with lower DC power signal, while using PIN pipe as electric switch
It can guarantee the stability switched between working frequency points and rapidity.
3, the switch switching circuit that the present invention designs switches using mechanical knob and switchs, mechanical knob switching
Switch has M gear, and each gear corresponds to a working frequency；By can be manually rotated mechanical knob switching switch, at M
A tuning and match circuit switch-on coil are selected in gear, to select the resonance frequency point of coil；It is cut using mechanical knob
The advantage for changing switch is: commissioning device that is simple to operate, not needing professional operator and profession；Meanwhile by
Using mechanical knob when switching, so can effectively ensure that only one working frequency points of coil are at work
State, to guarantee the normal operation of equipment.
4, (conventional MR imaging apparatus is needle for the radio-frequency coil in conventional MR imaging apparatus
To H imaging), the advantage of multifrequency point radio-frequency coil is: two even more originals can be realized on a magnetic resonance equipment
Daughter nucleus imaging, has widened the purposes of an equipment, has reduced cost, has very strong social effect and economic benefit.
Detailed description of the invention
Fig. 1 is the schematic diagram of single channel planar coil module of the present invention；
Fig. 2 is the schematic diagram of single channel planar coil of the present invention；
Fig. 3 a is the tuning of first frequency point radio-frequency coil and match circuit figure in the embodiment of the present invention；
Fig. 3 b is the tuning of second frequency point radio-frequency coil and match circuit figure in the embodiment of the present invention；
Fig. 3 c is the tuning of third frequency point radio-frequency coil and match circuit figure in the embodiment of the present invention；
Fig. 4 a is that figure is placed in the space of the multifrequency point radio-frequency coil of N=16 in the embodiment of the present invention；
Fig. 4 b is the placement figure of one group of coil (8) in the same plane in the embodiment of the present invention.
Specific embodiment
As shown in Figure 1, in the present embodiment, a kind of multifrequency point array radio frequency reception line in MR imaging apparatus
Circle system is made of N number of single channel planar coil module；Each single channel planar coil module includes: single channel planar line
Circle 1, M tuning and match circuit 2, frequency handover circuit 3 and pre-amplification circuit 4；
Wherein, single channel planar coil 1 is separately connected M tuning and match circuit 2；M tuning is with match circuit 2 with before
Set the connection of amplifying circuit 4；Frequency handover circuit 3 is connected between single channel planar coil 1 and M tuning and match circuit 2；It adjusts
It is humorous to be made of with match circuit 2 tuning capacitance and matching capacitance；It is accessed by 3 switching surface coil 1 of frequency handover circuit
Tuning and match circuit 2 realize the switching between multifrequency point.In the present invention, three resonance frequency points of coil design are respectively used to
Under 0.35T field strength1H imaging,3He imaging and129Xe imaging.
Single channel planar coil module detects the core of measured body in MR imaging apparatus using single channel planar coil 1
After magnetic resonance signal, M tuning tuning corresponding with match circuit 2 is selected to connect with match circuit by frequency handover circuit 3
Enter into single channel planar coil 1, so that NMR signal is transmitted to preceding storing with match circuit by selected tuning
Decoupling and enhanced processing are carried out in big circuit 4, thus the NMR signal that obtains that treated.
As shown in Figure 1, there are three the frequency point that resonates, institutes for each coil in multifrequency point RF receiving coil in the present embodiment
To require three tunings of design and match circuit in each coil, these three tunings are respectively corresponded with match circuit1H at
As,3He imaging and129Xe imaging.In Fig. 1, C1, C3, C5 are respectively1H imaging,3He imaging,129The tuning electricity of Xe imaging
Hold, C2, C4, C6 are respectively1H imaging,3He imaging,129The matching capacitance of Xe imaging.In general, for convenience load after tuning with
Match, we replace tuning capacitance and matching capacitance with fixed capacity is in parallel with tunable capacitor.In order to reduce electronics member device
Influence of the part to coil, all capacitors are the capacitors of no magnetic, high Q.
As shown in Figure 1, frequency handover circuit 3 includes: direct current driving power supply 31, knob switches switch 32, M radio frequency is gripped
Stream circle 33, M switch PIN diode are to 34 and M ground connection PIN diode to 35；Wherein, ground connection PIN diode 35 can
It is connected while switch PIN diode 34 are connected in DC driven 31, effect is the flip-flop removed in circuit, elimination pair
The influence of coil signal.The core of frequency handover circuit 3 is PIN diode, and the characteristic of PIN pipe is just equivalent to a switch, instead
In an off state, positively biased Shi Zewei opening state when partially.RF switch is designed with PIN pipe, lower dc power can be used
Signal controls powerful radiofrequency signal.The specific workflow of frequency handover circuit is as follows: being selected by mechanical knob 32
Switch PIN diode 34 and ground connection PIN diode 35 is connected by DC driven 31 in the tuning of switch-on coil and match circuit,
To select the resonance frequency point of coil, using mechanical knob when due to switching, so can effectively ensure that coil only
There are a working frequency points to be at working condition.
Knob switching switch 32 is provided with M gear, and each gear respectively corresponds different working frequency points；Each gear
On be correspondingly provided with radio-frequency choke 33；Radio-frequency choke 33 is connected with corresponding switch PIN diode to 34；Switch PIN
Diode pair 34 is connected to corresponding ground connection PIN diode to 35；Ground connection PIN diode connects pumping line at 35 therebetween position
Ground；
Frequency handover circuit 3 is the working frequency points needed for being selected using knob switching switch 32, direct current driving power supply 31
Switch PIN diode is connected to 34 and ground connection PIN diode to 35 by radio-frequency choke 33 on relevant work frequency point, from
And tuning corresponding with required working frequency points is linked into single channel planar coil 1 with match circuit, realize multifrequency
Switching between point.
As shown in Fig. 2, the present invention devises the array radio-frequency coil in 16 channels, single radio frequency coil using
Circular flat coil, working frequency points that there are three coils, their corresponding atomic nucleus are1H、3He and129Xe.According to Larmor
The calculation formula of precession frequency: f0=B0γ (wherein, f0For Larmor precession frequency, B0For static magnetic field strength, γ is atom
The gyromagnetic ratio of core) it calculates1H、3He and129The Larmor precession frequency of Xe is respectively f1=14.902MHz, f2=
11.351MHz, f3=4.12MHz (under the field strength of 0.35T),1H、3He and129The Larmor precession frequency of Xe is the work of coil
Working frequency.Due to1H、3He with129The Larmor precession frequency difference of Xe is larger, it is contemplated that129The limit of the Larmor precession frequency of Xe
System, for coil in design, the inductance value of coil should estimate formula, determining coil according to the inductance of coil between 1~2 μ H
Dimensional parameters are as follows: the diameter D of coil is 120mm, and line width W is 3mm, and line spacing is 3mm, and the number of turns N of coil is 2.Coil
Inductance value actual measurement are as follows: 14.962MHz (1H imaging) resonant frequency lower coil inductance value be 1.5946 μ H, In
11.351MHz(3He imaging) resonant frequency lower coil inductance value be 1.5561 μ H, 4.12MHz (129Xe imaging) be total to
The inductance value of vibration frequency lower coil is 1.5123 μ H, and the inductance value of coil is between 1~2 estimated μ H.
Fig. 3 a is1The tuning of H imaging and match circuit, under conditions of zero load, tuning capacitance C1=56pF, matching capacitance
C2=11.65pF, for convenience load after tuning and matching, by tuning capacitance C1 be equivalent to fixed capacity C11 (30pF),
C12 (20pF) is in parallel with tunable capacitor C13's (variation range of C13 is 0~10pF), and matching capacitance C2 is equivalent to fixed electricity
It is in parallel with tunable capacitor C22 (variation range of C22 is 0~10pF) to hold C21 (5pF)；Fig. 3 b is3He imaging tuning with
With circuit, under conditions of zero load, tuning capacitance C3=103.5pF, matching capacitance C4=16.6pF, after loading for convenience
It tunes and matches, tuning capacitance C3 is equivalent to fixed capacity C31 (100pF), and (variation range of C32 is 0 with tunable capacitor C32
~10pF) parallel connection, matching capacitance C4 is equivalent to fixed capacity C41 (10pF) and the tunable capacitor C42 (variation range of C42
For the parallel connection of 0~10pF)；Fig. 3 c is129The tuning of Xe imaging and match circuit, under conditions of zero load, tuning capacitance C5=
Tuning capacitance C5 is equivalent to fixed electricity by 880pF, matching capacitance C6=42.3pF, tuning and matching after loading for convenience
Holding C51 (820pF), C52 (50pF) and tunable capacitor C53, (variation range of C53 is in parallel for 0~10pF's), by matching capacitance
C6 be equivalent to fixed capacity C61 (30pF), C62 (5pF) and tunable capacitor C63 (variation range of C63 is 0~10pF) and
Connection.
Fig. 4 a is that figure is placed in space of the array radio-frequency coil in 16 channels in detection object, and 16 coils are divided into two groups
(every group 8), are respectively placed in the rear and front end of detection object.Fig. 4 b is the placement of one group of coil (8) in the same plane
Scheme, is overlapped and places between adjacent windings, it is therefore an objective to eliminate the close coupling between coil, the circle center distance between adjacent windings is
85mm~95mm.Simultaneously as the coupling between non-adjacent coil is smaller, can by using low-impedance preamplifier into
Row decoupling.
Claims (1)
1. a kind of multifrequency point array RF receiving coil system in MR imaging apparatus, it is characterized in that by N number of list
Channel plane coil module composition；Each single channel planar coil module include: single channel planar coil (1), M tuning with
With circuit (2), frequency handover circuit (3) and pre-amplification circuit (4)；
The single channel planar coil (1) is separately connected the M tuning and match circuit (2)；Described M tunes and matches electricity
Road (2) is connect with the pre-amplification circuit (4)；The frequency handover circuit (3) is connected on the single channel planar coil (1)
Between M tuning and match circuit (2)；The tuning is made of with match circuit (2) tuning capacitance and matching capacitance；
The frequency handover circuit (3) includes: direct current driving power supply (31), knob switching switch (32), M radio-frequency choke
(33), M switch PIN diode is to (34) and M ground connection PIN diode to (35)；
The knob switching switch (32) is provided with M gear, and each gear respectively corresponds different working frequency points；Each shelves
The radio-frequency choke (33) are correspondingly provided on position；The radio-frequency choke (33) and corresponding switch PIN diode pair
(34) it is connected；The switch PIN diode is connected to (34) with corresponding ground connection PIN diode to (35)；The ground connection
PIN diode is to pumping line ground connection at (35) therebetween position；
The frequency handover circuit (3) is the working frequency points needed for being selected using knob switching switch (32), and the direct current drives
Switch PIN diode is connected to (34) and ground connection by the radio-frequency choke (33) on relevant work frequency point in dynamic power supply (31)
PIN diode is to (35), so that tuning corresponding with required working frequency points is linked into the single-pass with match circuit
In road planar coil (1), the switching between multifrequency point is realized；
The single channel planar coil module is detected in MR imaging apparatus using the single channel planar coil (1) and is tested
After the NMR signal of body, select the M tuning corresponding to match circuit (2) by the frequency handover circuit (3)
Tuning and match circuit be linked into the single channel planar coil (1) so that the NMR signal pass through selected by
Tuning and match circuit be transmitted in the pre-amplification circuit (4) carry out decoupling and enhanced processing, thus after obtaining processing
NMR signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710326299.3A CN107121652B (en) | 2017-05-10 | 2017-05-10 | For the multifrequency point array RF receiving coil system in MR imaging apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710326299.3A CN107121652B (en) | 2017-05-10 | 2017-05-10 | For the multifrequency point array RF receiving coil system in MR imaging apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107121652A CN107121652A (en) | 2017-09-01 |
| CN107121652B true CN107121652B (en) | 2019-11-08 |
Family
ID=59727006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710326299.3A Active CN107121652B (en) | 2017-05-10 | 2017-05-10 | For the multifrequency point array RF receiving coil system in MR imaging apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107121652B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3696561A1 (en) * | 2019-02-14 | 2020-08-19 | Koninklijke Philips N.V. | Switchable impedance matching for noise-based motion detection in magnetic resonance imaging |
| CN113921239B (en) * | 2021-11-02 | 2024-06-04 | 深圳市联影高端医疗装备创新研究院 | Coil system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101403715A (en) * | 2008-11-14 | 2009-04-08 | 中国科学院电工研究所 | Nano-upgrading sample nuclear magnetic resonance detection digital receiver |
| CN202841115U (en) * | 2012-10-09 | 2013-03-27 | 中兴通讯股份有限公司 | Multiband aerial tuned circuit and wireless terminal |
| CN103257331A (en) * | 2012-02-16 | 2013-08-21 | 上海联影医疗科技有限公司 | Double-frequency radio-frequency coil |
| CN103698725A (en) * | 2013-11-11 | 2014-04-02 | 深圳先进技术研究院 | Multi-channel radio frequency coil interface device for magnetic resonance imaging system |
| CN104067136A (en) * | 2012-01-17 | 2014-09-24 | 皇家飞利浦有限公司 | Multi-resonant T/R antenna for MR image generation |
| CN105552494A (en) * | 2016-01-28 | 2016-05-04 | 华南理工大学 | Adjustable flat band-pass and band-stop filter |
| CN105759230A (en) * | 2016-02-25 | 2016-07-13 | 哈尔滨医科大学 | Quad-band radio frequency surface coil for multi-nuclear magnetic resonance imaging (MRI) |
-
2017
- 2017-05-10 CN CN201710326299.3A patent/CN107121652B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101403715A (en) * | 2008-11-14 | 2009-04-08 | 中国科学院电工研究所 | Nano-upgrading sample nuclear magnetic resonance detection digital receiver |
| CN104067136A (en) * | 2012-01-17 | 2014-09-24 | 皇家飞利浦有限公司 | Multi-resonant T/R antenna for MR image generation |
| CN103257331A (en) * | 2012-02-16 | 2013-08-21 | 上海联影医疗科技有限公司 | Double-frequency radio-frequency coil |
| CN202841115U (en) * | 2012-10-09 | 2013-03-27 | 中兴通讯股份有限公司 | Multiband aerial tuned circuit and wireless terminal |
| CN103698725A (en) * | 2013-11-11 | 2014-04-02 | 深圳先进技术研究院 | Multi-channel radio frequency coil interface device for magnetic resonance imaging system |
| CN105552494A (en) * | 2016-01-28 | 2016-05-04 | 华南理工大学 | Adjustable flat band-pass and band-stop filter |
| CN105759230A (en) * | 2016-02-25 | 2016-07-13 | 哈尔滨医科大学 | Quad-band radio frequency surface coil for multi-nuclear magnetic resonance imaging (MRI) |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107121652A (en) | 2017-09-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7042222B2 (en) | Phased array knee coil | |
| EP2073033B1 (en) | A switchable birdcage coil | |
| US7292038B2 (en) | Double-balanced double-tuned CP birdcage with similar field profiles | |
| EP2089733B1 (en) | Multi-functional nmr probe | |
| US7622928B2 (en) | RF traps for radio frequency coils used in MRI | |
| US7973531B2 (en) | Detuning a radio-frequency coil | |
| US9459331B2 (en) | RF coil and magnetic resonance imaging device | |
| US6552544B2 (en) | Detunable coil assembly and method of detuning RF coil for MRI | |
| US20100253333A1 (en) | Dual tuned volume coils adapted to provide an end ring mode | |
| US20070079253A1 (en) | Hybrid tem/birdcage coil for mri | |
| US7855559B2 (en) | Circuit and apparatus for decoupling RF surface coils | |
| JP2010518935A (en) | Sinusoidally resonating radio frequency volume coil for high field magnetic resonance applications | |
| JP2004513718A (en) | RF surface resonator | |
| CN107121652B (en) | For the multifrequency point array RF receiving coil system in MR imaging apparatus | |
| US20230078150A1 (en) | Double-resonant coil, array of double-resonant coils, and use thereof | |
| US5162739A (en) | Balanced multi-tuned high-power broadband coil for nmr | |
| US6795037B2 (en) | Radio-frequency antenna for a magnetic resonance system | |
| US11493579B2 (en) | Multi-tune magnetic resonance imaging (MRI) coil using different matching impedances | |
| US20080157770A1 (en) | Dual-tuned tem/birdcage hybrid volume coil for human brain and spectroscopy | |
| WO2023124446A1 (en) | Magnetic resonance system and circuit | |
| CN108663642B (en) | Tuning and detuning structure and method of radio frequency coil | |
| US8125226B2 (en) | Millipede surface coils | |
| US11269031B2 (en) | Magnetic resonance imaging (MRI) radio frequency (RF) coil tuning, matching, decoupling, and balun circuit |
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 |