Transmission device of magnetic resonance system and magnetic resonance system

Abstract

The invention provides a transmission device of a magnetic resonance system and the magnetic resonance system. The transmission device comprises a conversion circuit, a first optical module, an optical fiber, a second optical module and a receiving circuit, the conversion circuit is connected with a radio frequency coil and a first optical module of the magnetic resonance system, and the conversion circuit is used for receiving a reference signal and a radio frequency signal collected by the radio frequency coil and generating a first output signal; the first optical module is connected with an optical fiber, the first optical module is used for converting the first output signal into an optical signal, and the optical fiber is used for transmitting the optical signal; the second optical module is connected with the optical fiber and the receiving circuit, the second optical module is used for converting the optical signal into a second output signal, and the receiving circuit is used for processing the second output signal to obtain a magnetic resonance signal. Radio frequency signals are transmitted through the optical fiber, the optical fiber has good anti-electromagnetic interference and high stability, optical signal attenuation is low, the anti-interference capability can be improved, and the transmission distance can be prolonged.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a transmission device and a magnetic resonance system. Background Technology

[0002] Nuclear Magnetic Resonance Imaging (NMRI), also known as spin imaging or magnetic resonance imaging (MRI), uses the principle of nuclear magnetic resonance to detect the emitted electromagnetic waves by applying an external gradient magnetic field, based on the different attenuations of the released energy in different structural environments within a substance, and obtains an image of the internal structure of the object based on the electromagnetic waves.

[0003] In existing magnetic resonance systems, the radio frequency coils transmit radio frequency signals to the control console of the magnetic resonance system via coaxial cables for data processing. However, the radio frequency signals transmitted via coaxial cables are susceptible to external interference. Summary of the Invention

[0004] The main technical problem addressed by this application is to provide a transmission device and a magnetic resonance system for a magnetic resonance system, which can solve the technical problem that radio frequency signals transmitted via coaxial cables are easily subject to external interference in the prior art.

[0005] In a first aspect, this application provides a transmission device for a magnetic resonance system, including a conversion circuit, a first optical module, an optical fiber, a second optical module, and a receiving circuit; the conversion circuit is connected to the radio frequency coil of the magnetic resonance system and the first optical module respectively, and the conversion circuit is used to receive a reference signal and a radio frequency signal collected by the radio frequency coil, and generate a first output signal; the first optical module is connected to the optical fiber, and the first optical module is used to convert the first output signal into an optical signal, and the optical fiber is used to transmit the optical signal; the second optical module is connected to the optical fiber and the receiving circuit respectively, and the second optical module is used to convert the optical signal into a second output signal, and the receiving circuit is used to process the second output signal to obtain a magnetic resonance signal.

[0006] In some embodiments, the conversion circuit includes a comparator, a first input terminal of which is connected to the radio frequency coil of the magnetic resonance system, a second input terminal of which receives the reference signal, and an output terminal of which is connected to the first optical module. The comparator is used to compare the radio frequency signal with the reference signal to generate a first digital signal, and to use the first digital signal as the first output signal.

[0007] In some embodiments, the magnetic resonance system has multiple radio frequency coils and multiple conversion circuits, the multiple conversion circuits being configured corresponding to the multiple radio frequency coils; the transmission device further includes a first current source circuit and multiple signal processing circuits, the multiple signal processing circuits being configured corresponding to the multiple conversion circuits, each of the signal processing circuits receiving the first output signal from the corresponding conversion circuit, the first current source circuit being connected to the multiple signal processing circuits, and the first current source circuit being used to supply power to the multiple signal processing circuits.

[0008] In some embodiments, each of the signal processing circuits includes a first low-noise amplifier, a first impedance matching circuit, and a DC bias. The first low-noise amplifier is connected to the conversion circuit and the first impedance matching circuit, respectively. The first low-noise amplifier is used to amplify the first output signal, and the first impedance matching circuit is used to transmit the amplified first output signal. The DC bias is connected to the first impedance matching circuit, the first current source circuit, and the first optical module, respectively. The DC bias is used to combine the amplified first output signal and the DC signal and output them to the first optical module.

[0009] In some embodiments, the first optical module includes a plurality of light-emitting diodes (LEDs) and a multiplexer. A first current source circuit is connected to the plurality of LEDs and is used to power the plurality of LEDs. The plurality of LEDs are correspondingly configured with DC biasers of the plurality of signal processing circuits. Each LED is connected to both the DC biaser and the multiplexer. The multiplexer is connected to the optical fiber and is used to convert the plurality of first output signals into the optical signal.

[0010] In some embodiments, the conversion circuit further includes a control circuit and a switching circuit, the switching circuit being connected between the DC bias and the first current source circuit, and the control circuit being configured to control the switching circuit to disconnect when a detuning signal is received.

[0011] In some embodiments, the second optical module includes an optical demultiplexer for separating lasers of different wavelengths in the optical signal; the receiving circuit includes a plurality of signal receiving circuits, each of which is used to process the laser; each signal receiving circuit includes a photodetector, a second impedance matching circuit, and a second low-noise amplifier, the photodetector being connected to the optical demultiplexer and the second impedance matching circuit respectively, the second low-noise amplifier being connected to the second impedance matching circuit, and the second low-noise amplifier being used to output the magnetic resonance signal.

[0012] In some embodiments, the first optical module includes a first digital optical module, which is connected to the comparator and the optical fiber respectively, and is used to output the optical signal based on the first digital signal; the second optical module includes a second digital optical module, which is connected to the optical fiber, and is used to convert the optical signal into a second digital signal.

[0013] In some embodiments, the reference signal includes a sinusoidal signal, and the receiving circuit is used to filter, down-convert, and nonlinearly compensate the second digital signal to obtain the magnetic resonance signal.

[0014] Secondly, this application provides a magnetic resonance system, including a hospital bed, a radio frequency coil, the aforementioned transmission device, and a magnetic resonance reconstruction processor; The hospital bed is used to support the object being tested, and the radio frequency coil is installed on the hospital bed to receive the radio frequency signal excited by the object being tested; The transmission device is connected to the radio frequency coil and the magnetic resonance reconstruction processor respectively, and is used to transmit the radio frequency signal. The magnetic resonance reconstruction processor obtains the magnetic resonance signal from the transmission device. The magnetic resonance reconstruction processor includes an electronic processor programmed to reconstruct the extracted magnetic resonance signals to generate a reconstructed magnetic resonance image.

[0015] The transmission device for the magnetic resonance system of this application includes a conversion circuit, a first optical module, an optical fiber, a second optical module, and a receiving circuit. The conversion circuit is connected to the radio frequency coil of the magnetic resonance system and the first optical module, respectively. The conversion circuit is used to receive a reference signal and a radio frequency signal collected by the radio frequency coil, and to generate a first output signal based on the radio frequency signal and the reference signal. The first optical module is connected to the optical fiber and is used to convert the first output signal into an optical signal. The optical fiber is used to transmit the optical signal. The second optical module is connected to the optical fiber and the receiving circuit, respectively. The second optical module is used to convert the optical signal into a second output signal. The receiving circuit is used to process the second output signal to obtain a magnetic resonance signal. Transmitting the radio frequency signal via optical fiber has advantages over existing coaxial cables. Optical fiber has good electromagnetic interference resistance and strong stability. The optical signal is transmitted through total internal reflection within the optical fiber, resulting in low optical signal attenuation, which improves the anti-interference capability and transmission distance of the transmission device.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the frame of the first embodiment of the transmission device of the magnetic resonance system provided in this application; Figure 2 A schematic diagram of the frame of a second embodiment of the transmission device for the magnetic resonance system provided in this application; Figure 3 for Figure 2 A schematic diagram of the first embodiment of the receiving circuit; Figure 4 for Figure 3 A simulation diagram of the first embodiment in which the receiving circuit performs nonlinear compensation on the received signal; Figure 5 A circuit diagram of a third embodiment of the transmission device for the magnetic resonance system provided in this application; Figure 6 A circuit diagram of a fourth embodiment of the transmission device for the magnetic resonance system provided in this application; Figure 7 A schematic diagram of the framework of the first embodiment of the magnetic resonance system provided in this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0021] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0024] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0025] The transmission device for the magnetic resonance system provided in this application can be applied to magnetic resonance imaging (MRI). A typical MRI system includes an MRI gantry containing a main magnet, which can be composed of superconducting coils to generate the main magnetic field. During MRI, the subject is supported by a patient bed. As the bed moves, the subject is moved into a region with a relatively uniform magnetic field distribution within the main magnetic field. Atomic nuclei in the human body carry positive charges, and the nuclei of many elements, such as ¹H, ¹⁹FT, and ³¹P, undergo spin motion. Normally, the arrangement of the nuclear spin axes is random, but when placed in an external magnetic field, the spatial orientation of the nuclear spin transitions from disorder to order. As a result, the spinning nuclei also precess around the vector of the external magnetic field at an angle between their spin axis and the vector direction of the external magnetic field. This precession is called Larmor precession, much like the rotation of a spinning top under the Earth's gravity. The magnetization vector of the spin system gradually increases from zero, and when the system reaches equilibrium, the magnetization intensity reaches a stable value. If the nuclear spin system is subjected to external forces, such as radio frequency excitation of the nuclei at a certain frequency, a resonance effect can be induced. In the magnetic resonance system, the pulse control unit controls the radio frequency pulse generation unit to generate radio frequency pulses. These pulses are amplified by an amplifier, pass through a switching control unit, and are ultimately generated by the radio frequency coil. The spin nuclei also precess in the radio frequency direction; this superimposed precession state is called nutation. After the radio frequency pulse stops, the excited nuclei in the spin system cannot maintain this state and will return to their original alignment in the magnetic field, releasing a weak energy as a radio signal. The local coil or receiving coil detects these signals and enables spatial resolution, thus obtaining the magnetic resonance signal corresponding to the moving nuclei. The magnetic resonance signal in this embodiment can also be referred to as a "spin signal," "precession signal," or voxel emission signal.

[0026] Please see Figure 1 As shown, Figure 1 This is a schematic diagram of the first embodiment of the transmission device for the magnetic resonance system provided in this application. The transmission device 100 of the magnetic resonance system in this embodiment includes a conversion circuit 10, a first optical module 20, an optical fiber 30, a second optical module 40, and a receiving circuit 50.

[0027] The magnetic resonance system includes a radio frequency coil 200, which can be used to receive the magnetic resonance signal generated by the object being detected under excitation; the radio frequency signal collected by the radio frequency coil 200 refers to the magnetic resonance signal generated by the object being detected under excitation.

[0028] The conversion circuit 10 is connected to both the radio frequency coil 200 and the first optical module 20. The conversion circuit 10 receives radio frequency signals from the radio frequency coil 200 and also receives a reference signal. The reference signal includes, but is not limited to, a sine wave, a triangular wave, or a DC signal. A sine wave is a periodic signal with a single frequency component, and its waveform is a mathematical sine curve. A triangular wave is a periodic signal with symmetrical triangular characteristics. A DC signal is a signal with a constant current direction and a constant amplitude. In some embodiments, the conversion circuit 10 generates and receives the reference signal.

[0029] The conversion circuit 10 generates a first output signal and transmits it to the first optical module 20. The first optical module 20 receives the first output signal and converts it into an optical signal, which may include, but is not limited to, a pulsed laser signal or a laser carrier wave. The first optical module 20 is connected to an optical fiber 30, which transmits the optical signal.

[0030] The second optical module 40 is connected to both the optical fiber 30 and the receiving circuit 50. The second optical module 40 receives optical signals from the optical fiber 30 and converts the optical signals into a second output signal. The receiving circuit 50 receives the second output signal from the second optical module 40 and processes the second output signal to obtain a magnetic resonance signal.

[0031] In some embodiments, the first optical module 20 is an optical transmitting module, and the second optical module 40 is an optical receiving module.

[0032] In this embodiment, the transmission device 100 of the magnetic resonance system transmits radio frequency signals through optical fiber 30. That is, the optical signal transmitted by optical fiber 30 carries the radio frequency signal. Compared with the coaxial cable of the prior art, optical fiber 30 has good anti-electromagnetic interference and strong stability. The optical signal is transmitted by total internal reflection in optical fiber 30, and the optical signal attenuation is low, which can improve the anti-interference capability and transmission distance of the transmission device 100.

[0033] According to some embodiments of this application, please refer to Figure 2 As shown, Figure 2 This is a schematic diagram of the second embodiment of the transmission device for the magnetic resonance system provided in this application. The conversion circuit 10 of this embodiment includes a comparator 11, which includes, but is not limited to, a high-speed comparator. A high-speed comparator is capable of rapidly comparing two analog input signals and inputting digital logic signals. For example, a high-speed comparator can compare two analog input signals within nanoseconds or picoseconds.

[0034] The first input terminal of comparator 11 is connected to the radio frequency coil 200 of the magnetic resonance system, the second input terminal of comparator 11 receives the reference signal, and the output terminal of comparator 11 is connected to the first optical module 20.

[0035] The first input terminal of comparator 11 receives a radio frequency (RF) signal from the RF coil 200. Comparator 11 is used to compare the RF signal with a reference signal to generate a first digital signal, which is then used as the first output signal. Both the RF signal and the reference signal are analog input signals, and the reference signal includes, but is not limited to, a sine wave, a triangular wave, or a DC signal.

[0036] In some embodiments, comparator 11 is used to compare the radio frequency (RF) signal with a reference signal. When the RF signal is greater than or equal to the reference signal, comparator 11 outputs a high level, and the first digital signal generated by comparator 11 is 1. When the RF signal is less than the reference signal, comparator 11 outputs a low level, and the first digital signal generated by comparator 11 is 0. Therefore, the first digital signal generated by comparator 11 can be 0101, and the amplitude of the first digital signal is 1 bit. In other embodiments, the amplitude of the first digital signal can be 2 bits or 8 bits, etc.

[0037] In some embodiments, the conversion circuit 10 of this embodiment further includes an oscillator 12, which is used to generate a reference signal. The second input terminal of the comparator 11 is connected to the oscillator 12 so that the second input terminal of the comparator 11 receives the reference signal.

[0038] The conversion circuit 10 in this embodiment includes a comparator 11, which compares the radio frequency signal with a reference signal to generate a first digital signal, and uses the first digital signal as a first output signal. By converting the radio frequency signal and the reference signal into the first digital signal through the comparator 11, the conversion of the analog signal is realized, thereby improving the conversion speed.

[0039] According to some embodiments of this application, such as Figure 2 As shown, the first optical module 20 in this embodiment includes a first digital optical module 21, which is connected to the comparator 11 and the optical fiber 30 respectively.

[0040] The first digital optical module 21 is used to output an optical signal based on a first digital signal, that is, the first digital optical module 21 is used to convert the first digital signal into an optical signal so that the optical fiber 30 can transmit the optical signal. For example, the first digital optical module 21 is used to output a pulsed laser signal based on the first digital signal, and the optical fiber 30 is used to transmit the pulsed laser signal.

[0041] The second optical module 40 in this embodiment includes a second digital optical module 41, which is connected to the optical fiber 30 and the receiving circuit 50 respectively. The second digital optical module 41 is used to convert optical signals into second digital signals. For example, the second digital optical module 41 is used to convert pulsed laser signals into second digital signals, and the second digital signals can be approximately the same as the first digital signals.

[0042] The first optical module 20 in this embodiment includes a first digital optical module 21, and the second optical module 40 includes a second digital optical module 41. By using the first digital optical module 21 and the second digital optical module 41, the cost of the transmission device 100 of the magnetic resonance system can be reduced, and the anti-interference capability and transmission distance of the transmission device 100 can be improved.

[0043] According to some embodiments of this application, please refer to Figure 3 As shown, Figure 3 for Figure 2 A schematic diagram of the first embodiment of the receiving circuit. The receiving circuit 50 in this embodiment includes a balancer (balun) 31, a first filter module 32, a down-conversion module 33, a second filter module 34, and a nonlinear compensation module 35.

[0044] The switching device 31 is connected to the second digital optical module 41 and the first filter module 32 respectively. The switching device 31 refers to a circuit element used to convert between balanced and unbalanced signals. For example, if the first digital signal and the second digital signal are differential signals, the switching device 31 is used to convert the differential signal into a received signal (e.g., a radio frequency signal).

[0045] The downconversion module 33 is connected to the first filter module 32 and the second filter module 34 respectively. The first filter module 32 is used to filter and extract the received signal, the downconversion module 33 is used to downconvert the received signal to a zero intermediate frequency (IF) received signal, and the second filter module 34 is used to filter and extract the zero IF received signal.

[0046] The nonlinear compensation module 35 is connected to the second filtering module 34, and the nonlinear compensation module 35 is used to perform nonlinear compensation on the received signal.

[0047] In some embodiments, the reference signal includes a sinusoidal signal, and the receiving circuit 50 is used to filter, down-convert, and nonlinearly compensate the second digital signal to obtain a magnetic resonance signal. Specifically, the weighing switch 31 is used to convert the second digital signal into a received signal, the first filtering module 32 filters and decimates the received signal, the down-conversion module 33 down-converts the received signal to a zero-IF received signal, the second filtering module 34 filters and decimates the zero-IF received signal, and the nonlinear compensation module 35 performs nonlinear compensation on the received signal to obtain a magnetic resonance signal.

[0048] Specifically, the input signal of the nonlinear compensation module 35 is x(n), which is the received signal without nonlinear compensation. The output signal of the nonlinear compensation module 35 is y(n), which is the magnetic resonance signal, where n is a positive integer greater than or equal to 1. The output signal y(n) satisfies the following formula: y(n)=f[x(n+m),...x(n),...,x(nk)]; Where m and k are natural numbers. For example, m=1, k=1, y(n)=f[x(n+1),x(n),x(n-1)] means that the output signal y(n) is related to the input signal x(n-1) of the previous time, the input signal x(n) of the current time, and the input signal x(n+1) of the next time.

[0049] In some embodiments, the nonlinear compensation module 35 is used to perform polynomial compensation on the input signal x(n). Polynomial compensation is a method of correcting system errors or disturbances by introducing a polynomial function model. The output signal y(n) satisfies the following formula: y(n)=a1*x(n)+a2*x(n)*|x(n)|+.....+am*x(n)*|x(n)| m-1 ; Among them, the parameters a1, a2, ..., am can be obtained through testing and correction calculations using existing technologies.

[0050] Please see Figure 4 As shown, Figure 4 for Figure 3 A simulation diagram of the first embodiment of the receiving circuit performing nonlinear compensation on the received signal. Figure 4 The horizontal axis represents frequency, in Hz; Figure 4 The vertical axis represents the power spectral density, in dB. Figure 4 Curve 401 represents the input signal x(n), curve 402 represents the reference signal (i.e., the sine signal), and curve 403 represents the output signal y(n), i.e., the magnetic resonance signal. In this embodiment, the nonlinear compensation module 35 is used to perform polynomial compensation on the input signal x(n) to obtain the output signal y(n), which can suppress spectrum regeneration and improve the transmission quality of the transmission device 100.

[0051] According to some embodiments of this application, please refer to Figure 5 As shown, Figure 5 This is a circuit diagram of a third embodiment of the transmission device for a magnetic resonance system provided in this application. The magnetic resonance system of this embodiment has multiple radio frequency coils 200 and multiple conversion circuits 10, with each conversion circuit 10 corresponding to one radio frequency coil 200. The transmission device 100 of this embodiment also includes a first current source circuit 51 and multiple signal processing circuits 52.

[0052] In this configuration, multiple signal processing circuits 52 are correspondingly arranged with multiple conversion circuits 10, meaning that each signal processing circuit 52 corresponds to one conversion circuit 10. For example, a magnetic resonance system has four radio frequency coils 200 and four conversion circuits 10, and a transmission device 100 includes four signal processing circuits 52, each of which is connected to a corresponding conversion circuit 10.

[0053] Multiple signal processing circuits 52 receive multiple first output signals from multiple conversion circuits 10; that is, each signal processing circuit 52 receives a first output signal from its corresponding conversion circuit 10. A first current source circuit 51 is connected to the multiple signal processing circuits 52 and is used to supply power to the power-consuming components in the multiple signal processing circuits 52.

[0054] In some embodiments, the first optical module 20 includes a plurality of light-emitting diodes (LEDs) 61 and a multiplexer (MUX) 62. A first current source circuit 51 is connected to the plurality of LEDs 61 and supplies power to the plurality of LEDs 61. The plurality of LEDs 61 are correspondingly arranged with a plurality of signal processing circuits 52, and each LED 61 is connected to both the signal processing circuit 52 and the multiplexer 62. Each LED 61 is used to convert a corresponding first output signal into an optical signal, and the multiplexer 62 is used to combine the multiple optical signals for transmission through the optical fiber 30; that is, the multiplexer 62 is used to convert multiple first output signals into optical signals.

[0055] For example, the transmission device 100 includes four signal processing circuits 52, and the first optical module 20 includes four light-emitting diodes 61. Each light-emitting diode 61 is connected to a corresponding signal processing circuit 52, and the four light-emitting diodes 61 are connected to a multiplexer 62. The four light-emitting diodes 61 are respectively used to emit a 1271nm laser carrier, a 1291nm laser carrier, a 1311nm laser carrier, and a 1331nm laser carrier. The laser carrier is used to carry the corresponding first output signal, and the optical signal can be the aforementioned laser carrier.

[0056] The transmission device 100 of this embodiment includes a first current source circuit 51 and multiple signal processing circuits 52. The multiple signal processing circuits 52 receive multiple first output signals from multiple conversion circuits 10. The first current source circuit 51 is used to power the multiple signal processing circuits 52. The first optical module 20 includes multiple light-emitting diodes 61 and a multiplexer 62. The multiple light-emitting diodes 61 are correspondingly arranged with the multiple signal processing circuits 52. Each light-emitting diode 61 is connected to both the signal processing circuit 52 and the multiplexer 62. The multiple first output signals are converted into optical signals by the multiplexer 62 for transmission through the optical fiber 30. This enables the optical fiber 30 to transmit multiple radio frequency signals, which can improve the transmission capacity of the optical fiber 30, increase the utilization rate of the laser spectrum, and ensure that the channels of different wavelengths of the optical fiber 30 are independent of each other, reducing mutual interference. In addition, compared with the coaxial cable of the prior art, the optical fiber 30 has good anti-electromagnetic interference and strong stability. The optical signal is transmitted by total internal reflection within the optical fiber 30, and the optical signal attenuation is low, which can improve the anti-interference capability and transmission distance of the transmission device 100.

[0057] According to some embodiments of this application, such as Figure 5 As shown, each signal processing circuit 52 in this embodiment includes a first low noise amplifier (LNA) 53, a first impedance matching circuit 54, and a DC biaser 55.

[0058] The first low-noise amplifier 53 is connected to the conversion circuit 10 and the first impedance matching circuit 54, respectively; the first current source circuit 51 is further connected to the first low-noise amplifier 53 and the first impedance matching circuit 54, respectively, for supplying power to the first low-noise amplifier 53 and the first impedance matching circuit 54. The first low-noise amplifier 53 amplifies the first output signal and suppresses noise, while the first impedance matching circuit 54 transmits the first output signal amplified by the first low-noise amplifier 53.

[0059] The DC bias unit 55 is connected to the first impedance matching circuit 54, the first current source circuit 51, and the first optical module 20, respectively. Specifically, the first terminal of the DC bias unit 55 is connected to the first impedance matching circuit 54 to receive the amplified first output signal; the second terminal of the DC bias unit 55 is connected to the first current source circuit 51 to receive the DC signal; and the third terminal of the DC bias unit 55 is connected to the corresponding light-emitting diode 61. The DC bias unit 55 is used to combine the amplified first output signal and the DC signal and output them to the light-emitting diode 61 of the first optical module 20.

[0060] In some embodiments, a plurality of light-emitting diodes 61 are correspondingly arranged with a plurality of DC biasers 55, and each light-emitting diode 61 is connected to both a DC biaser 55 and a multiplexer 62. For example, the light-emitting diode 61 can be a laser diode (LD) or a light emitter.

[0061] Each signal processing circuit 52 in this embodiment includes a first low-noise amplifier 53, a first impedance matching circuit 54, and a DC bias 55. The first low-noise amplifier 53 is used to amplify the first output signal and suppress noise. The first impedance matching circuit 54 is used to transmit the first output signal amplified by the first low-noise amplifier 53. The DC bias 55 is used to combine the amplified first output signal and the DC signal and output them to the first optical module 20. Noise can be reduced by the first low-noise amplifier 53.

[0062] According to some embodiments of this application, such as Figure 5 As shown, the second optical module 40 in this embodiment includes an optical demultiplexer (DMUX) 71, which is connected to the optical fiber 30. The optical demultiplexer 71 is used to separate lasers of different wavelengths in the optical signal. For example, the optical demultiplexer 71 is used to separate the optical signal into four different wavelengths of laser.

[0063] The receiving circuit 50 in this embodiment includes multiple signal receiving circuits 81, each of which is used to process the laser. The number of signal receiving circuits 81 is the same as the number of lasers of different wavelengths. For example, the optical demultiplexer 71 is used to separate the optical signal into four laser carriers of different wavelengths, and the four laser carriers of different wavelengths are respectively input to four signal receiving circuits 81 for processing.

[0064] In some embodiments, each signal receiving circuit 81 includes a photodetector 82, a second impedance matching circuit 83, and a second low-noise amplifier 84. The photodetector 82 is connected to the optical demultiplexer 71 and the second impedance matching circuit 83, respectively. The second low-noise amplifier 84 is connected to the second impedance matching circuit 83 and is used to output magnetic resonance signals.

[0065] In some embodiments, the receiving circuit 50 further includes a second current source circuit 85, which is connected to the photodetector 82, the second impedance matching circuit 83, and the second low-noise amplifier 84, respectively, for supplying power to the photodetector 82, the second impedance matching circuit 83, and the second low-noise amplifier 84. Both the second current source circuit 85 and the first current source circuit 51 can be current sources in the prior art, and will not be described in detail here.

[0066] The first optical module 20 of this application includes a multiplexer 62, and the second optical module 40 includes an optical demultiplexer 71. Wavelength division multiplexing (WDM) is realized through the multiplexer 62 and the optical demultiplexer 71. Multiple radio frequency signals can be transmitted through a single optical fiber 30 through the multiplexer 62, and different wavelengths of laser light in the optical signals can be separated through the optical demultiplexer 71.

[0067] In other embodiments, the transmission device 100 of the magnetic resonance system may also use coarse wavelength division multiplexing (CWDM) or dense wavelength division multiplexing (DWDM) instead of the laser wavelength division multiplexing of this embodiment. CWDM supports 18 channels with wavelengths ranging from 1270 nm to 1610 nm and a channel spacing of 20 nm; DWDM supports 48 channels at a wavelength spacing of 100 GHz and 96 channels at a wavelength spacing of 50 GHz.

[0068] According to some embodiments of this application, please refer to Figure 6 As shown, Figure 6 A circuit diagram of a fourth embodiment of the transmission device for the magnetic resonance system provided in this application. Figure 5 Compared to the transmission device 100 of the magnetic resonance system shown, the conversion circuit 10 of this embodiment further includes a control circuit 56 and a switching circuit 57. The switching circuit 57 is connected between the DC bias 55 and the first current source circuit 51, that is, one end of the switching circuit 57 is connected to the first current source circuit 51, and the other end of the switching circuit 57 is connected to a plurality of DC bias 55.

[0069] The control circuit 56, connected to the switching circuit 57, is used to control the switching circuit 57 to disconnect when a detuning signal is received. That is, the multiple DC biasers 55 are disconnected from the first current source circuit 51, and the multiple DC biasers 55 stop outputting. The control circuit 56 obtains the detuning signal from an external circuit. The detuning signal refers to the waveform distortion or abnormal energy distribution caused by frequency mismatch, nonlinear distortion, etc., during the transmission or processing of a signal (such as a radio frequency signal).

[0070] The conversion circuit 10 in this embodiment also includes a control circuit 56 and a switching circuit 57. The switching circuit 57 is connected between the DC bias 55 and the first current source circuit 51. The control circuit 56 is used to control the switching circuit 57 to disconnect when a detuning signal is received, which can improve the transmission quality of the transmission device 100.

[0071] This application also provides a magnetic resonance system; please refer to [link to relevant documentation]. Figure 7 As shown, Figure 7 This is a schematic diagram of the framework of a first embodiment of the magnetic resonance imaging (MRI) system provided in this application. The MRI system of this embodiment includes a hospital bed 400, a radio frequency coil 200, a transmission device 100, and an MRI reconstruction processor 300.

[0072] The bed 400 is used to carry the object to be tested, and the radio frequency coil 200 is set on the bed 400. The radio frequency coil 200 is used to receive the radio frequency signal excited by the object to be tested.

[0073] The transmission device 100 is connected to the radio frequency coil 200 and the magnetic resonance reconstruction processor 300 respectively. The transmission device 100 is used to transmit radio frequency signals. The transmission device 100 can be the transmission device 100 disclosed in the above embodiments, which will not be described again here.

[0074] The magnetic resonance reconstruction processor 300 acquires magnetic resonance signals from the transmission device 100. The magnetic resonance reconstruction processor 300 includes an electronic processor 301, which is programmed to reconstruct the extracted magnetic resonance signals to generate a reconstructed magnetic resonance image.

[0075] In summary, the transmission device 100 of the magnetic resonance system of this application transmits radio frequency signals through optical fiber 30. Compared with the coaxial cable of the prior art, optical fiber 30 has good anti-electromagnetic interference and strong stability. The optical signal is transmitted by total internal reflection in optical fiber 30, and the optical signal attenuation is low, which can improve the anti-interference capability and transmission distance of the transmission device 100.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A transmission device of a magnetic resonance system, characterized in that, The conversion circuit, the first optical module, the optical fiber, the second optical module and the receiving circuit; the conversion circuit is connected with the radio frequency coil of the magnetic resonance system and the first optical module respectively, the conversion circuit is used for receiving a reference signal and a radio frequency signal collected by the radio frequency coil, and a first output signal is generated; the first optical module is connected with the optical fiber, the first optical module is used for converting the first output signal into an optical signal, and the optical fiber is used for transmitting the optical signal; the second optical module is connected with the optical fiber and the receiving circuit respectively, the second optical module is used for converting the optical signal into a second output signal, and the receiving circuit is used for processing the second output signal to obtain a magnetic resonance signal.

2. The transmission device according to claim 1, characterized in that, The conversion circuit includes a comparator, a first input end of the comparator is connected with the radio frequency coil of the magnetic resonance system, a second input end of the comparator receives the reference signal, and an output end of the comparator is connected with the first optical module, the comparator is used for comparing the radio frequency signal with the reference signal to generate a first digital signal, and the first digital signal is used as the first output signal.

3. The transmission device according to claim 1 or 2, characterized in that, The magnetic resonance system has a plurality of radio frequency coils and a plurality of conversion circuits, the plurality of conversion circuits are correspondingly arranged with the plurality of radio frequency coils; the transmission device further includes a first current source circuit and a plurality of signal processing circuits, the plurality of signal processing circuits are correspondingly arranged with the plurality of conversion circuits, each signal processing circuit receives the first output signal from the corresponding conversion circuit, the first current source circuit is connected with the plurality of signal processing circuits, and the first current source circuit is used for supplying power to the plurality of signal processing circuits.

4. The transmission device according to claim 3, wherein Each signal processing circuit includes a first low-noise amplifier, a first impedance matching circuit and a DC biasing device, the first low-noise amplifier is connected with the conversion circuit and the first impedance matching circuit respectively, the first low-noise amplifier is used for amplifying the first output signal, and the first impedance matching circuit is used for transmitting the amplified first output signal; the DC biasing device is connected with the first impedance matching circuit, the first current source circuit and the first optical module respectively, and the DC biasing device is used for combining the amplified first output signal and the DC signal and outputting to the first optical module.

5. The transmission device according to claim 4, wherein The first optical module includes a plurality of light emitting diodes and a multiplexer, the first current source circuit is connected with the plurality of light emitting diodes, and the first current source circuit is used for supplying power to the plurality of light emitting diodes; the plurality of light emitting diodes are correspondingly arranged with the DC biasing devices of the plurality of signal processing circuits, each light emitting diode is connected with the DC biasing device and the multiplexer respectively, the multiplexer is connected with the optical fiber, and the multiplexer is used for converting a plurality of first output signals into the optical signal.

6. The transmission device according to claim 5, wherein The conversion circuit further includes a control circuit and a switch circuit, the switch circuit is connected between the DC biasing device and the first current source circuit, and the control circuit is used for controlling the switch circuit to be disconnected when a detuning signal is received.

7. The transmitting apparatus of claim 3, wherein The second optical module comprises an optical demultiplexer for separating laser beams of different wavelengths in the optical signal; the receiving circuit comprises a plurality of signal receiving circuits, each of which is used for processing the laser beams; each of the signal receiving circuits comprises a photodetector, a second impedance matching circuit and a second low noise amplifier, the photodetector is connected with the optical demultiplexer and the second impedance matching circuit respectively, the second low noise amplifier is connected with the second impedance matching circuit, and the second low noise amplifier is used for outputting the magnetic resonance signal.

8. The transmitting apparatus of claim 2, wherein, The first optical module comprises a first digital optical module connected with the comparator and the optical fiber respectively, and the first digital optical module is used for outputting the optical signal based on the first digital signal; the second optical module comprises a second digital optical module connected with the optical fiber, and the second digital optical module is used for converting the optical signal into a second digital signal.

9. The transmitting apparatus of claim 8, wherein, The reference signal comprises a sinusoidal signal, and the receiving circuit is used for filtering, down-converting and non-linearly compensating the second digital signal to obtain the magnetic resonance signal.

10. A magnetic resonance system, characterized by The transmission device comprises a patient bed, a radio frequency coil, a transmission device according to any one of claims 1-9, and a magnetic resonance reconstruction processor. The patient bed is used for carrying a detection object, and the radio frequency coil is arranged on the patient bed and used for receiving a radio frequency signal excited by the detection object. The transmission device is connected with the radio frequency coil and the magnetic resonance reconstruction processor respectively and used for transmitting the radio frequency signal, and the magnetic resonance reconstruction processor acquires a magnetic resonance signal from the transmission device. The magnetic resonance reconstruction processor comprises an electronic processor programmed to reconstruct the extracted magnetic resonance signal to generate a reconstructed magnetic resonance image.

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