Radio frequency cable trap assembly with indicator circuit

Abstract

Disclosed herein is a radio frequency cable trap assembly 100 having a radio frequency cable trap circuit 102. The radio frequency cable trap is configured to suppress induction of alternating current energy at a predetermined magnetic resonance imaging operating frequency in a cable 200 for a magnetic resonance imaging coil 302, 310, 314. The assembly 100 further includes an indication circuit 104 having an output unit 111 configured to output an indication signal upon reaching a predetermined upper threshold by the suppressed energy. The indication circuit 104 is configured to determine reaching of the predetermined upper threshold using a portion of the suppressed energy transferred from the radio frequency cable trap circuit 102 to the indication circuit 104 via an energy transfer coupling between the radio frequency cable trap circuit 102 and the indication circuit 104.

Description

Technical Field

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[0001] The present invention relates to magnetic resonance imaging, particularly to a radio frequency trap for a cable of a magnetic resonance imaging coil.

Background Art

[0002] Undesired currents, such as common mode currents that can flow along the shield of a cable within a magnetic resonance system, can negatively affect the performance of a radio frequency coil, for example, by affecting coil decoupling and tuning. Further, the energy radiated from the cable can generate heat that poses a risk of burning the patient.

Summary of the Invention

Problems to be Solved by the Invention

[0003] To suppress such currents, a radio frequency cable trap circuit that introduces a high impedance to common mode currents on the cable can be used. There are several known designs for radio frequency cable trap circuits within a magnetic resonance system, such as tank circuits and bazooka baluns.

Means for Solving the Problems

[0004] The present invention provides a radio frequency cable trap assembly, a cable for a magnetic resonance imaging coil having such a radio frequency cable trap assembly, a magnetic resonance imaging coil having such a cable, and a magnetic resonance imaging system having such a magnetic resonance imaging coil.

[0005] In one aspect, the present invention provides a radio frequency cable trap assembly having a radio frequency cable trap circuit. The radio frequency cable trap is configured to suppress the induction of alternating energy at a predetermined magnetic resonance imaging operating frequency in a cable for a magnetic resonance imaging coil.

[0006] The assembly further includes an indicator circuit having an output unit configured to output an indicator signal when the suppressed energy, i.e., the energy resulting from suppression, reaches a predetermined upper threshold. In response to the output of the indicator signal, the indicator circuit uses a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indicator circuit via an energy transfer coupling between the radio frequency cable trap circuit and the indicator circuit.

[0007] The reaching of a predetermined upper threshold by suppressed energy may be sensed and / or measured, for example, through direct or indirect sensing and / or measurement. For example, suppressed energy may be sensed and / or measured using a suitable sensor, and / or other physical quantities indicating suppressed energy, such as power, current, voltage, and / or temperature arising from suppressed energy, may be sensed and / or measured using a suitable sensor. Suppressed energy and / or other physical quantities arising from suppressed energy, such as power, current, voltage, and / or temperature, may be sensed and / or measured, for example, within a radio frequency cable trap circuit. For example, physical quantities indicating suppressed energy, such as power, current, voltage, and / or temperature arising from suppressed energy due to energy transmitted from the radio frequency cable trap circuit to the indicator circuit via energy transfer coupling, may be sensed and / or measured within the indicator circuit.

[0008] The indicator signal indicates that a predetermined upper threshold has been reached by the suppressed energy. Depending on the sensing and / or measurements performed within the radio frequency cable trap assembly, the indicator signal may also indicate other sensory values ​​sensed and / or measured within the radio frequency cable trap assembly.

[0009] A portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indicator circuit may be used, for example, to supply energy to the output unit to output an indicator signal. A portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indicator circuit may be used, for example, to activate the output mode of the output unit. A portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indicator circuit may be used, for example, to indicate that a predetermined upper threshold has been reached.

[0010] The indicator circuit may be configured, for example, to determine when a predetermined upper threshold is reached. For example, the indicator circuit may be configured to determine when a predetermined upper threshold is reached by using a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indicator circuit via an energy transfer coupling between the radio frequency cable trap circuit and the indicator circuit.

[0011] The instruction signal may take different forms in different examples, for example, in the form of a visual, acoustic, and / or radio signal to warn the operator of the magnetic resonance system that a predetermined upper threshold has been reached due to suppressed energy. In other examples, the instruction signal may be used to trigger other components of the magnetic resonance imaging system. In one example, the instruction signal can automatically trigger the cessation of a magnetic resonance scan performed by the magnetic resonance imaging system.

[0012] Although described in the context of cables for magnetic resonance imaging coils, the radio frequency cable trap assemblies described herein may be used for any galvanic connections located in or intended to be located within the B1 field of a magnetic resonance imaging system.

[0013] Magnetic resonance imaging (MRI) is an imaging technique based on the principle of nuclear magnetic resonance, that is, the idea that atomic nuclei with non-zero spin possess a magnetic moment. In medical MRI, atomic nuclei with non-zero spin are typically hydrogen nuclei found in the bodies of humans or animals. Radio frequency (RF) waves that form the B1 excitation field are directed towards atomic nuclei in an external magnetic field, leading to proton excitation and subsequent proton relaxation processes. Proton relaxation produces radio frequency signals emitted by the atomic nuclei that can be sensed and processed to form an image.

[0014] A typical magnetic resonance imaging system generally includes a magnet, such as a superconducting magnet, that generates a strong static magnetic field; a gradient coil that generates a linear change in the static magnetic field; a radio frequency transmitting coil that generates a B1 excitation field; and a radio frequency receiving coil that senses the magnetic resonance radio frequency signal emitted from the relaxing atomic nuclei. Typically, cables, such as coaxial cables, are used in the magnetic resonance system for the controlled transmission of the radio frequency signal within the coils. Furthermore, the coils of the magnetic resonance system, like the radio frequency coils, are connected via cable transmission lines, such as coaxial cable transmission lines, to a computer unit that controls the magnetic resonance system and processes the acquired magnetic resonance signals.

[0015] In magnetic resonance imaging systems, cables placed within the system can unintentionally couple to the radio frequency transmission magnetic field, or B1 field, and act like unwanted antennas. This is known as the antenna effect. Wires, and generally elongated conductive objects, placed within the B1 field can function like antennas, capturing electromagnetic waves and extracting energy from them. The antenna can generate standing wave patterns of voltage and current, which are maximized when its length is half the radio frequency wavelength. Such currents can cause radio frequency induction heating of the antenna, such as a cable, creating a risk of burns to patients near the heated antenna.

[0016] For example, a coaxial cable has an outer shield and an inner conductor separated from each other by a dielectric material. Together, they form a radio frequency transmission line with defined and stable propagation characteristics, such as velocity and characteristic impedance. This allows the outer shield to prevent the pickup of undesirable frequencies. A magnetic resonance signal acquired by a radio frequency coil of a magnetic resonance system may be transmitted over the coaxial cable, for example, in differential modes on the inner and outer surfaces of the inner and outer conductors.

[0017] However, sources outside the coaxial cable can induce unintended currents in the outer shield, thus generating unintended signals that can adversely affect, for example, the signal-to-noise ratio of a radio frequency receiver coil. In the case of high magnetic fields, the outer surface of the outer conductor of the coaxial cable can electromagnetically couple to the radiated magnetic field or the radio frequency transmission magnetic field, i.e., the B1 magnetic field. This coupling can induce undesirable common-mode currents. Due to the skin effect, the inner and outer surfaces of the coaxial shield can be effectively isolated at radio frequencies. Nevertheless, common-mode currents can cause problems by coupling to nearby dielectrics, such as the patient and radio frequency coils. Residual coupling of common-mode currents to the received signal path can result in the cable itself acting like an undesirable antenna. This can cause burns to the patient. Furthermore, coil filling efficiency and power efficiency may be reduced. In addition, depending on the cable's wiring, common-mode currents can generate high local electric fields, thereby causing surface burns to the patient's body.

[0018] For these reasons, radio frequency cable trap circuits are used with cables in magnetic resonance imaging systems. Radio frequency cable trap circuits can have the beneficial effect of introducing high impedance. This impedance can enable the suppression of alternating current, such as alternating current, at a given magnetic resonance imaging operating frequency. For example, impedance may be introduced into common-mode currents on cables. In magnetic resonance imaging systems, such alternating energy, for example in the form of common-mode current, can be induced through the body coil during the transmission of radio frequency pulses. Common-mode current refers to a situation where a portion of the conductor current does not match an opposing current of equal magnitude. This is a portion of the total current that causes a feed line to behave like a single wire. Currents flowing in common mode can be reduced by a sufficiently high common-mode impedance. Therefore, increasing the common-mode impedance can reduce, or suppress, common-mode currents on cables or any other galvanic connections such as twin-axe or twisted-pair connections.

[0019] A radio frequency cable trap circuit can form a resonant structure having, for example, at least one electrical energy storage unit and at least one magnetic energy storage unit that form a high impedance to the common mode on the cable. This can be achieved, for example, by directly forming the resonant structure from a portion of the transmission line, or, for example, mainly by inductive coupling between the resonant structure and the cable.

[0020] MR-compatible cable trap circuits may be based on resonant structures that store both electrical and magnetic energy. Different methods may be used to construct such resonant trap structures. For example, the coil may be made from a transmission line such that the common mode senses the inductor. The inductor may be connected to a parallel capacitor to form a parallel resonant circuit, for example. However, the capacitor does not need to be realized by a lumped component. Capacitive coupling between the windings of the coil can function, for example, as an electrical energy storage unit. The coil may be formed by another structure, for example, and coupled to a cable, for example, mainly inductively. Alternatively, a coaxial structure may be used to form an inductively coupled structure instead of a coil. This may involve directly using the cable as an internal component, for example. The length may be selected to 1 / 4 wavelength to form a monopole resonator structure, for example, called a bazooka balun.

[0021] The radio frequency cable trap assembly is designed without magnetic materials to ensure magnetic resonance compatibility. A resonant structure is used to form a high impedance at a given magnetic resonance imaging operating frequency. For narrowband pulses used in magnetic resonance imaging systems, a high impedance at a given magnetic resonance imaging operating frequency may be sufficient. In special cases, multiple nuclei may also be used for imaging. Subsequently, for example, a multi-resonant radio frequency cable trap circuit resonating for multiple different magnetic resonance imaging operating frequencies, or multiple radio frequency cable trap assemblies resonating for different magnetic resonance imaging operating frequencies, may be used. Furthermore, multi-tenant structures combining two or more modes can be realized.

[0022] Even when radio frequency cable trapping circuits are used, errors and / or problems can occur. These errors and / or problems may, for example, cause insufficient suppression of induced AC energy by the radio frequency cable trapping circuit. A predetermined upper threshold may be defined such that adverse effects on the patient due to heating caused by induced energy exceeding a safe temperature are excluded, or at least unlikely. Thus, when the suppressed energy reaches a predetermined upper threshold, the resulting risk may be indicated by an indicator signal output by the indicator circuit. A predetermined upper threshold may be defined, for example, as a temperature threshold. When each temperature threshold is reached, it may be concluded that the suppression of induced AC energy is insufficient. Furthermore, it may be concluded that an error and / or problem has occurred. Such errors and / or problems may include, for example, non-ideal adjustment of the radio frequency cable trapping circuit, defects in the radio frequency cable trapping circuit, defects in the cable and / or critical placement of the cable. These errors and / or problems can either be corrected, or the radio frequency cable trapping circuit and / or cable can be replaced. The modifications may include, for example, modifying the adjustment of the radio frequency cable trap circuit and / or modifying the cable arrangement.

[0023] Such errors and / or problems can also occur with unconnected coils in magnetic resonance imaging systems. In the event of errors and / or problems, the cable and / or radio frequency cable trap circuit represents a risk, for example, the risk of skin burns due to electromagnetic coupling, resulting in the induction of AC energy that may be too large and / or insufficiently suppressed. Therefore, these examples can enhance patient safety for both connected and unconnected coils.

[0024] An important operation of the magnetic resonance imaging system can result in a high voltage induced across both ends of the radio frequency cable trap circuit, which can generate a high current within the radio frequency cable trap circuit.

[0025] The suppressed energy refers to the energy resulting from the suppression, that is, the amount of residual energy remaining after the suppression.

[0026] For example, a power threshold indicating a predetermined upper limit threshold can be sensed, for example, by a radio frequency cable trap circuit and / or an instruction circuit, using a power sensor circuit constituted by a radio frequency cable trap assembly. The power sensor circuit is configured to sense, for example, the power resulting from the suppressed energy, that is, the amount of suppressed energy induced in the radio frequency cable trap circuit per unit time. The power sensor circuit is configured to sense, for example, the power resulting from the transmission portion of the suppressed energy, that is, the amount of suppressed energy transmitted from the radio frequency cable trap circuit to the instruction circuit per unit time via the energy transmission coupling between the radio frequency cable trap circuit and the instruction circuit.

[0027] For example, a predetermined upper limit threshold as an energy threshold, or another energy threshold indicating a predetermined upper limit threshold, can be sensed, for example, by a radio frequency cable trap circuit and / or an instruction circuit, using an energy sensor circuit constituted by a radio frequency cable trap assembly. The energy sensor circuit is configured to sense, for example, the suppressed energy induced in the radio frequency cable trap circuit. The energy sensor circuit is configured to sense, for example, the portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the instruction circuit via the energy transmission coupling between the radio frequency cable trap circuit and the instruction circuit.

[0028] For example, a current threshold indicating a predetermined upper limit threshold may be sensed, for example, by a current sensor circuit constituted by a radio frequency cable trap assembly by means of a radio frequency cable trap circuit and / or an indication circuit. The current sensor circuit is configured to sense, for example, a current generated from the suppressed energy induced in the radio frequency cable trap circuit. The current sensor circuit is configured to sense, for example, a current generated from a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indication circuit via an energy transfer coupling between the radio frequency cable trap circuit and the indication circuit.

[0029] For example, a voltage threshold indicating a predetermined upper limit threshold may be sensed, for example, by a voltage sensor circuit constituted by a radio frequency cable trap assembly by means of a radio frequency cable trap circuit and / or an indication circuit. The voltage sensor circuit is configured to sense, for example, a voltage generated from the suppressed energy induced in the radio frequency cable trap circuit. The voltage sensor circuit is configured to sense, for example, a voltage generated from a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indication circuit via an energy transfer coupling between the radio frequency cable trap circuit and the indication circuit.

[0030] For example, a temperature threshold indicating a predetermined upper limit threshold may be sensed, for example, by a temperature sensor circuit constituted by a radio frequency cable trap assembly by means of a radio frequency cable trap circuit and / or an indication circuit. The temperature sensor circuit is configured to sense, for example, a temperature generated from the suppressed energy induced in the radio frequency cable trap circuit. The temperature sensor circuit is configured to sense, for example, a temperature generated from a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the indication circuit via an energy transfer coupling between the radio frequency cable trap circuit and the indication circuit.

[0031] Embodiments may have the beneficial effect of enabling the detection of critical trap heating of a cable in which a radio frequency cable trap circuit and / or radio frequency cable trap assembly is used. Such heating may result from induced AC energy. The arrival of a potential critical or at least undesirable level of heating may be determined based on the arrival of a predetermined upper limit threshold by suppressed energy. This threshold may represent energy large enough to potentially cause undesirable or critical level heating. Therefore, an indication signal output for the arrival of a predetermined upper limit threshold by suppressed energy may indicate undesirable or critical level heating. Thus, the output may enable the cessation of the magnetic resonance imaging scan before the patient is injured by the heating, for example, suffers burns. The magnetic resonance imaging scan may be automatically stopped, for example, upon reception of an indication signal by the receiver of the magnetic resonance imaging system performing the magnetic resonance imaging scan. For example, a system-integrated body coil connected to the receiver chain may be used. The body coil may enable the sensing of signals within or slightly outside the MR bandwidth without requiring additional hardware. The receiving unit may forward the received instruction signal to the control unit of the magnetic resonance imaging system, but the control unit may stop the execution of the magnetic resonance imaging scan. When the magnetic resonance imaging scan is stopped, the induction of AC energy at a predetermined magnetic resonance imaging operating frequency in the cable may stop. Therefore, further heating of the cable and / or radio frequency cable trap circuit may stop, and the cable and / or radio frequency cable trap circuit may cool down again. Alternatively, the magnetic resonance imaging scan may be stopped by an operator operating the magnetic resonance imaging system upon receiving the output instruction signal. The instruction signal may indicate, for example, a detected problem with the radio frequency cable trap circuit and / or sensor values. The detected problem and / or sensor values ​​may be sent, for example, to a cloud server and / or written to a log file for later use such as a service.

[0032] When a magnetic resonance imaging scan is stopped, the cable and / or radio frequency cable trap circuit may be checked for potential errors, such as non-ideal adjustment of the radio frequency cable trap circuit, defects in the radio frequency cable trap circuit, defects in the cable and / or non-critical placement of the cable. If errors occur, these may be corrected, for example, or the radio frequency cable trap circuit and / or cable may be replaced. Corrections may include, for example, correcting the adjustment of the radio frequency cable trap circuit and / or correcting the placement of the cable.

[0033] The embodiment may have the beneficial effect of preventing the heating of the cable and / or radio frequency cable trap assembly to levels that could potentially be harmful to the patient. Therefore, by stopping the magnetic resonance imaging scan, for example, the patient being scanned may be protected from any hazards such as burns caused by heating of the cable and / or radio frequency cable trap circuit. This may be particularly beneficial in protecting sedated patients who are unable to report any problematic heating that occurs during sedation.

[0034] In another embodiment, the indicator circuit has a passive switch that is controlled by a portion of suppressed energy transmitted via an energy transfer coupling and configured to activate an output mode of the indicator circuit to output an indicator signal when the suppressed energy reaches a predetermined upper threshold. The embodiment may have the beneficial effect that the activation of the output mode of the indicator circuit, for example, the output unit of the indicator circuit, can be controlled based on the portion of suppressed energy transmitted and therefore based on the suppressed energy. For example, the output unit may be in a sleep mode and only activate when the suppressed energy reaches a predetermined upper threshold.

[0035] In another embodiment, the indicator circuit has a comparator configured to compare a parameter describing the portion of suppressed energy transmitted via energy transfer coupling with a reference parameter describing the attainment of a predetermined upper threshold. The indicator circuit is configured to activate an output mode when it determines, using the comparator, that the suppressed energy has reached a predetermined upper threshold. The embodiment may have the beneficial effect that the activation of the output mode of the indicator circuit, for example, the output unit of the indicator circuit, can be controlled based on the portion of suppressed energy transmitted and therefore the induced suppressed energy. For example, the output unit may be in a sleep mode and only activate when the suppressed energy has reached a predetermined upper threshold.

[0036] In another embodiment, the energy transfer coupling is an inductive coupling. Inductive or magnetic coupling refers to a type of coupling in which a change in the current flowing through one wire induces a voltage between the ends of another wire through electromagnetic induction. The changing current through the first wire generates a changing magnetic field around it, according to Ampère's laws of circuits. This changing magnetic field induces an electromotive force in the second wire, according to Faraday's laws of electromagnetic induction.

[0037] For example, a radio frequency cable trap circuit may be inductively coupled via its local magnetic field to an indicator circuit having a pickup loop for picking up an induced voltage. The radio frequency cable trap circuit can, for example, suppress AC in the cable at a predetermined magnetic resonance imaging operating frequency, e.g., 1.5T Larmor frequency. For sufficiently high power absorbed within the radio frequency cable trap circuit, the voltage induced in the indicator circuit can become large enough to allow for significant energy harvesting of the energy transmitted from the radio frequency cable trap circuit by the indicator circuit. The harvested energy may be large enough to power, for example, the transmission of an indicator signal by the indicator circuit to a magnetic resonance imaging system.

[0038] For example, an AC voltage may be induced in the indicator circuit by energy transfer. The induced AC voltage may be used, for example, by rectification to generate a DC voltage. The resulting DC voltage may be used to power an oscillator, such as a crystal oscillator, configured to transmit a pilot tone as an indicator signal. The pilot tone may be transmitted, for example, within the receiver bandwidth of a receiver in a magnetic resonance imaging system. For example, the pilot tone may indicate the detection of heating in a radio frequency cable trap circuit that has reached a predetermined upper threshold. The magnetic resonance imaging system may be configured to detect a pilot tone transmitted within the receiver bandwidth using a receiver. By detecting the reception of the pilot tone, the magnetic resonance imaging system can detect heating in a radio frequency cable trap circuit that has reached a predetermined upper threshold.

[0039] Furthermore, the indicator circuit may include, for example, a microcontroller, which may be powered using energy harvesting. This microcontroller may enable the indicator circuit to collect and transmit additional data, such as the temperature and power level of the radio frequency cable trap circuit and / or the indicator circuit.

[0040] In another embodiment, energy transfer coupling is capacitive coupling. Capacitive coupling refers to the transfer of energy in an electrical network by displacement currents between circuit nodes induced by an electric field. In its simplest implementation, capacitive coupling may be achieved by placing capacitors between nodes.

[0041] In another embodiment, the instruction circuit has an energy harvesting circuit configured to recover a portion of the suppressed energy transmitted via an energy transfer coupling. The instruction circuit is configured to use the harvested energy to output an instruction signal.

[0042] The embodiment may have the beneficial effect of integrating an energy harvesting function into the radio frequency cable trap assembly. This energy harvesting function may be used to supply energy to an indicator circuit, enabling the indicator circuit to output an indicator signal using an output unit. Thus, the indicator circuit does not need an independent energy supply, but may be supplied via energy harvesting whenever some of the suppressed energy is transferred from the radio frequency cable trap circuit to the partial indicator circuit via energy transfer coupling. Since the objective of the indicator circuit is to reach a predetermined upper threshold with suppressed energy, the indicator circuit may only require power supply if there is a non-negligible amount of suppressed energy, i.e., a non-negligible amount of energy induced despite the suppression by the radio frequency cable trap circuit. Such non-negligible suppressed energy can supply energy to the indicator circuit via energy harvesting. Thus, power supply to the indicator circuit can be guaranteed as needed. Accordingly, power supply to the indicator circuit may be independent of any additional connection of the radio frequency cable trap assembly to an external power supply. It may also function even when the cables and / or magnetic resonance imaging coils provided with the radio frequency cable trap assembly are not connected to a power supply.

[0043] A key operation of the magnetic resonance imaging system can generate a high voltage induced across the ends of a radio frequency cable trap circuit, which can generate a high current within the radio frequency cable trap circuit. Such a high current can further result in the generation of a high radio frequency magnetic field within the radio frequency cable trap circuit. This locally generated radio frequency magnetic field may be high enough to be used for energy harvesting by an indicator circuit of the intelligent radio frequency cable trap assembly. The indicator circuit may be configured to recover energy using, for example, the voltage induced within the indicator circuit by the radio frequency magnetic field generated by the radio frequency cable trap circuit. As soon as this voltage harvested by the indicator circuit reaches a critical limit, i.e., a predetermined upper threshold which may be defined as a voltage threshold, the indicator circuit may communicate with the magnetic resonance imaging system to indicate that the predetermined upper threshold has been reached and / or to request that the magnetic resonance imaging system stop acquiring magnetic resonance imaging data. In further embodiments, additional information such as temperature, current, force, magnetic field, etc., may be sensed using appropriate sensors configured by the intelligent radio frequency cable trap assembly and similarly transmitted to the magnetic resonance imaging system.

[0044] For example, the harvested energy may be used by an indicator circuit to power an onboard transmitter and transmit data about the state of the radio frequency trap circuit to a host system, such as a magnetic resonance imaging system.

[0045] Radio frequency cable trap circuits are intended to adequately suppress the induction of AC energy within a cable. Unless an error or other problem occurs, the energy induced in the cable by radio frequency radiation, particularly pulses with a given magnetic resonance imaging operating frequency, can be effectively suppressed by the radio frequency cable trap circuit. Thus, a given upper threshold for the suppressed energy can only be reached, for example, in the event of some error. Such errors may include, for example, non-ideal adjustment of the radio frequency cable trap circuit, defects in the cable on which the radio frequency cable trap assembly is used, or critical placement. In such cases, it is still possible that large energies, such as strong currents, may be induced in the cable and / or radio frequency cable trap circuit. Such large energies induced despite suppression can lead, for example, to critical heating of the cable and / or radio frequency cable trap circuit.

[0046] Such error scenarios requiring an indicator circuit may also include power supply errors. For example, some components of a magnetic resonance imaging system using a radio frequency cable trap circuit assembly may not need to be connected to a power supply. For example, cables and / or magnetic resonance imaging coils using a radio frequency cable trap circuit assembly may not need to be connected. Using energy harvesting to supply energy to an indicator circuit may have the beneficial effect of making the power supply of the indicator circuit independent of errors associated with connecting to an external power supply. Such errors related to an external power supply may result from, for example, an operational error. For example, the operator may have simply forgotten to plug in such an external power supply. An indicator circuit powered using energy harvesting may be independent of such operational errors.

[0047] In another embodiment, the instruction circuit has a battery unit configured to supply energy for outputting an instruction signal. The embodiment may have the beneficial effect of providing a self-sufficient power source for the instruction circuit together with the battery unit. Energy harvesting and the battery unit may be combined, and in normal operation, the energy harvesting may be configured, for example, to recharge the battery unit, and may consume only a small amount of energy over time with no impact on normal operation, i.e., backlash. Thus, it may be ensured that the battery unit remains charged to supply energy for outputting an instruction signal as needed. When the suppressed energy reaches a predetermined upper limit threshold, for example, a passive switch may trigger the output of an instruction signal driven from the charged battery unit.

[0048] In another embodiment, the instruction signal includes a visual signal. The output unit has a visual signal emitting circuit configured to emit a visual signal.

[0049] In another embodiment, the instruction signal includes an acoustic signal. The output unit has an acoustic signal emitting circuit configured to emit an acoustic signal.

[0050] In another embodiment, the instruction signal includes a radio signal. The output unit has a radio signal transmission circuit configured to transmit the radio signal.

[0051] In another embodiment, the instruction circuit is configured to transmit a radio signal in a radio frequency band that is within or near a predetermined magnetic resonance imaging operating frequency bandwidth, which includes a predetermined magnetic resonance imaging operating frequency, and at least partially overlaps with that bandwidth.

[0052] For example, the radio frequency band is a frequency band comprised of the magnetic resonance imaging bandwidth. A receiver component of a magnetic resonance imaging system, such as one or more receiver coils, may be configured to receive magnetic resonance signals, i.e., radio frequency signals, within the magnetic resonance imaging bandwidth. Transmitting radio signals at radio frequencies having the magnetic resonance imaging bandwidth, i.e., the magnetic resonance imaging bandwidth, by a radio frequency cable trap assembly placed within this magnetic resonance imaging system may have the beneficial effect of enabling the magnetic resonance imaging receiver component to receive and process the radio signals. The receiver component of the magnetic resonance imaging system may be highly sensitive to receiving radio frequency signals within the magnetic resonance imaging bandwidth.

[0053] A magnetic resonance imaging (MRCA) system may include a main magnet configured to generate a main magnetic field for polarization of a sample, one or more shim coils for compensating for shifts in the uniformity of the main magnetic field, a gradient system used to identify the area to be scanned, and a radio frequency system configured to excite the sample using radio frequency pulses and detect the resulting magnetic resonance signal. The magnetic resonance signal in MRCA is generated by a resonance process resulting from excitation by radio frequency pulses. The radio frequency system may have a transmitting component, i.e., one or more transmitter coils configured to generate radio frequency pulses used to excite the sample. The nuclei of interest for which MRCA imaging data is to be acquired have their own resonance frequencies in the radio frequency portion of the electromagnetic spectrum. To excite the nuclei of interest, radio frequency pulses are transmitted using these resonance frequencies as the MRCA imaging operating frequency. The radio frequency system may have a receiving component, i.e., one or more receiver coils configured to receive the magnetic resonance signal within the MRCA imaging bandwidth. The receiver coils detect the radio frequency-excited oscillations generated by the precession of the magnetic moments of the nuclei in the sample. Therefore, the magnetic resonance signal acquired by the receiver coil is an induced electromagnetic field oscillating within the magnetic resonance imaging bandwidth.

[0054] For example, the instruction circuit is configured to transmit a radio signal in a radio frequency band that does not include a predetermined magnetic resonance imaging operating frequency.

[0055] In another embodiment, the instruction circuit is configured to transmit the radio signal in a frequency band outside a predetermined magnetic resonance imaging operating frequency band, including a predetermined magnetic resonance imaging operating frequency.

[0056] For example, RFID technology may be used to transmit a signaling signal. The signaling circuit may include, for example, an RFID chip. For example, the power obtained by the signaling circuit from the radio frequency cable trap circuit may be high enough to trigger and / or power the RFID chip. The RFID chip may be configured to submit a unique ID assigned to the RFID chip, and therefore to the radio frequency cable trap assembly having the RFID chip. The unique ID may be encoded in the radio frequency signal transmitted as a signaling signal by the RFID chip. The signal transmitted by the RFID chip may be transmitted in a radio frequency band different from the magnetic resonance imaging bandwidth received by a receiver component of a magnetic resonance imaging system configured to receive magnetic resonance signals for acquiring magnetic resonance imaging data. The signal transmitted by the RFID chip may be received by a dedicated radio frequency receiver. This dedicated radio frequency receiver may be configured by the magnetic resonance imaging system. For example, the dedicated radio frequency receiver may be mounted on a patient table or in the bore of the magnetic resonance imaging system. A unique ID, comprised of instruction signals transmitted by an RFID chip, may enable a receiver, such as a magnetic resonance imaging system (MSR) with a dedicated RFID receiver, to identify the RFID cable trap assembly that triggers the issuance of each instruction signal, i.e., the origin of the instruction signal. Receipt of an instruction signal may, for example, cause the MSRS or a computer system controlling the MSRS to stop the MSRS scanning performed by the MSRS. Furthermore, a request may be issued, for example, instructing the operator to reposition the cable having the RFID cable trap assembly identified by the unique ID. If an induction signal is repeatedly received for the same RFID cable trap assembly, a repair action may be triggered. For example, a repair request may be issued, instructing the operator to repair the identified RFID cable trap assembly and / or the cable having the identified RFID cable trap assembly.For example, a counter is used to count the number of instruction signals issued to a radio frequency cable trap assembly identified by a unique ID. The output of a repair request may be triggered when the counter reaches a predetermined threshold.

[0057] In another embodiment, the instruction circuit includes one or more sensor circuits for acquiring sensor data and a microcontroller. The microcontroller is configured to control the acquisition of sensor data and the transmission of the acquired sensor data via radio signals.

[0058] Using a microcontroller, the instruction circuit may be enabled to collect and transmit additional sensor data acquired by, for example, the sensor circuit.

[0059] In another embodiment, one or more sensor circuits are configured to acquire sensor data for one or more of the following parameters: temperature of the radio frequency cable trap assembly, voltage in the radio frequency cable trap circuit resulting from suppressed energy, voltage in the indicator circuit resulting from the transmitted portion of suppressed energy, current in the radio frequency cable trap circuit resulting from suppressed energy, current in the indicator circuit resulting from the transmitted portion of suppressed energy, magnetic field strength, ambient temperature, and ambient humidity.

[0060] For example, the indicator circuit, as a pickup circuit, may be configured such that the power picked up by the indicator circuit is high enough to supply sufficient power to drive the microcontroller in response to the suppressed energy induced in the radio frequency cable trap circuit when a predetermined upper threshold is reached. The microcontroller may be configured to feature, for example, the sensing of an electromagnetic field, environmental parameters such as temperature or humidity, or motion. The microcontroller may be further configured to report the sensing results wirelessly to a remote router, for example, via WIFI, Bluetooth (LE), or any other power-efficient wireless communication method. The submitted data may be used to control the magnetic resonance imaging system, in particular to prevent situations that are dangerous to the patient, such as those described above. Such dangerous situations may be prevented, for example, by automatically stopping the magnetic resonance imaging scan operation performed by the magnetic resonance imaging system.

[0061] Temperature and / or power may be measured using sensors having switches controlled by, for example, local bolometers, thermistors, or thermally dependent mechanical expansion. The thermally dependent mechanical expansion may be implemented using, for example, bimetallic components. A bimetallic component has layers of different metals with at least different coefficients of thermal expansion. Due to the difference in thermal expansion coefficients, temperature changes are converted into mechanical displacements. The bimetallic component may have, for example, the shape of a strip or a disk.

[0062] The instruction circuit may include, for example, a voltage sensor configured to measure the voltage on a radio frequency cable trap circuit. Furthermore, a comparator may be provided, configured to compare the voltage sensed on the radio frequency cable trap circuit by the voltage sensor with a predetermined voltage threshold. If the sensed voltage reaches the predetermined voltage threshold, an instruction signal may be issued by the instruction circuit, for example, to prompt the scan controller of the magnetic resonance imaging system to stop the scan being performed by the magnetic resonance imaging system.

[0063] In another embodiment, the transmitted radio signal includes an ID of a radio frequency cable trap assembly that identifies the radio frequency cable trap assembly transmitting the radio signal.

[0064] A radio frequency cable trap assembly may be used to prevent and / or detect currents on galvanic structures within an MRI system. It may be applied, for example, to a magnetic resonance imaging coil, particularly an MRI receiving coil. For instance, the radio frequency cable trap may be connected to the magnetic resonance imaging coil or implemented in any type of cable connected to the magnetic resonance imaging coil.

[0065] In another embodiment, the present invention provides a cable for a magnetic resonance imaging coil having a radio frequency cable trap assembly, one of the radio frequency cable trap assemblies described above. The cable may be, for example, a coaxial cable.

[0066] In another embodiment, the present invention provides a magnetic resonance imaging coil having one of the above embodiments of a cable having a radio frequency cable trap assembly.

[0067] In another embodiment, the present invention provides a magnetic resonance imaging system having a magnetic resonance imaging coil in any of the above-described embodiments. The magnetic resonance imaging coil is provided with a cable having a radio frequency cable trap assembly.

[0068] It is understood that one or more of the above-described embodiments of the present invention can be combined, provided that the combined embodiments are not mutually exclusive.

[0069] As will be understood by those skilled in the art, aspects of the present invention may be embodied as apparatus, methods, or computer program products. Accordingly, aspects of the present invention may take the form of hardware embodiments as a whole, software embodiments as a whole (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware embodiments, all of which may be generally referred to herein as “circuits,” “modules,” or “systems.” Furthermore, aspects of the present invention may take the form of computer program products embodied in one or more computer-readable media in which computer executable code is embodied.

[0070] Any combination of one or more computer-readable media may be used. Computer-readable media may be computer-readable signal media or computer-readable storage media. As used herein, “computer-readable storage media” encompasses any tangible storage media capable of storing instructions executable by the processor or computing system of a computing device. Computer-readable storage media may also be referred to as computer-readable non-temporary storage media. Computer-readable storage media may also be referred to as tangible computer-readable media. In some embodiments, computer-readable storage media may also store data that can be accessed by the computing system of a computing device. Examples of computer-readable storage media include, but are not limited to, floppy disks, magnetic hard disk drives, solid-state hard disks, flash memory, USB thumb drives, random access memory, read-only memory (ROM), optical disks, magneto-optical disks, and register files of computing systems. Examples of optical disks include compact disks (CDs) and digital-purpose disks (DVDs), such as CD-ROMs, CD-RWs, CD-Rs, DVD-ROMs, DVD-RWs, or DVD-R discs. The term computer-readable storage medium also refers to various types of recording media that can be accessed by computer devices via a network or communication link. For example, data may be retrieved via a modem, the Internet, or a local area network. Computer executable code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, fiber optic cable, RF, or any suitable combination thereof.

[0071] A computer-readable signal medium may include, for example, a data signal that propagates, in which computer-executable code is embodied, either in the baseband or as part of a carrier wave. Such propagated signals may take any variety of forms, including but not limited to electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium, such a computer-readable medium not being a computer-readable storage medium, but which can communicate, propagate, or transmit programs for use by or in connection with an instruction execution system, device, or apparatus.

[0072] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is memory that can be directly accessed by a computing system. "Computer storage" or "storage" is a further example of a computer-readable storage medium. A computer storage device is any non-volatile computer-readable storage medium. In some embodiments, the computer storage device may be computer memory, or vice versa.

[0073] As used herein, “computational system” encompasses electronic components capable of executing programs, machine-executable instructions, or computer-executable code. References to computational systems, including examples of “computational systems,” should be interpreted as potentially including more than one computational system or processing core. A computational system may, for example, be a multi-core processor. A computational system may refer to a collection of computational systems within a single computer system or distributed across multiple computer systems. The term “computational system” should also be interpreted as potentially referring to a collection or network of computing devices, each having a processor or computational system. Machine-executable code or instructions may be executed by multiple computational systems or processors, which may be located within the same computing device or distributed across multiple computing devices.

[0074] Machine-executable instructions or computer-executable code may include instructions or programs that cause a processor or other computing system to perform an aspect of the present invention. Computer-executable code for performing an operation for an aspect of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the C programming language or similar programming languages, and compiled into machine-executable instructions. In some examples, the computer-executable code may be in the form of a high-level language or in a pre-compiled form and may be used with an interpreter that generates machine-executable instructions on the fly. In other examples, machine-executable instructions or computer-executable code may be in the form of programming to a programmable logic gate array.

[0075] Computer executable code may run entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or wide area network (WAN), or it may be connected to an external computer (for example, via the Internet using an Internet service provider).

[0076] Aspects of the present invention will be described with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each block or part of a block in a flowchart, diagram, and / or block diagram can be implemented by computer program instructions in the form of computer executable code, where applicable. Furthermore, it should be understood that blocks in different flowcharts, diagrams, and / or block diagrams can be combined if they are not mutually exclusive. These computer program instructions may be supplied to a general-purpose computer, a special-purpose computer, or a computer system of other programmable data processing equipment to manufacture a machine such that instructions executed via the computer system or other programmable data processing equipment generate means for performing functions / operations specified in one or more blocks of a flowchart and / or block diagram.

[0077] These machine-executable instructions or computer program instructions may be stored on a computer-readable medium that can instruct a computer, other programmable data processing device, or other device to function in a particular manner, such that the instructions stored on the computer-readable medium generate a product containing instructions that perform functions / operations specified in one or more blocks of a flowchart and / or block diagram.

[0078] Machine-executable instructions or computer program instructions may also be loaded into a computer, other programmable data processing device, or other device so that a series of operational steps are performed on the computer, other programmable data processing device, or other device, so as to generate a computer execution process that provides a process for performing a function / operation specified in one or more blocks of a flowchart and / or block diagram.

[0079] As used herein, “user interface” refers to an interface that enables a user or operator to interact with a computer or computer system. A “user interface” may also be referred to as a “human interface device.” A user interface may provide information or data to an operator and / or receive information or data from an operator. A user interface may enable input from an operator to be received by a computer and provide output from the computer to a user. In other words, a user interface may enable an operator to control or operate a computer, and the interface may enable the computer to demonstrate the effects of the operator’s control or operation. Displaying data or information on a display or graphical user interface is an example of providing information to an operator. Receiving data via a keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, gamepad, webcam, headset, pedal, wired glove, remote control, and accelerometer are all examples of user interface components that enable the reception of information or data from an operator.

[0080] As used herein, “hardware interface” includes interfaces that enable a computer system’s computing system to interact with and / or control external computing devices and / or equipment. Hardware interfaces may enable a computing system to transmit control signals or instructions to external computing devices and / or equipment. Hardware interfaces may also enable a computing system to exchange data with external computing devices and / or equipment. Examples of hardware interfaces include, but are not limited to, universal serial buses, IEEE 1394 ports, parallel ports, IEEE 1284 ports, serial ports, RS-232 ports, IEEE-488 ports, Bluetooth connections, wireless local area network connections, TCP / IP connections, Ethernet connections, control voltage interfaces, MIDI interfaces, analog input interfaces, and digital input interfaces.

[0081] As used herein, “display” or “display device” encompasses output devices or user interfaces configured to display images or data. Displays may output visual data, auditory data, and / or tactile data. Examples of displays include, but are not limited to, computer monitors, television screens, touchscreens, tactile electronic displays, braille screens, cathode ray tubes (CRTs), memory tubes, bistable displays, electronic paper, vector displays, flat panel displays, vacuum fluorescent displays (VFs), light-emitting diode (LED) displays, electroluminescent displays (ELDs), plasma display panels (PDPs), liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, projectors, and head-mounted displays.

[0082] Hereinafter, preferred embodiments of the invention will be described with reference to the drawings, merely as examples. [Brief explanation of the drawing]

[0083] [Figure 1] An example of a radio frequency cable trap assembly is shown. [Figure 2] Further examples of radio frequency cable trap assemblies are shown. [Figure 3] Further examples of radio frequency cable trap assemblies are shown. [Figure 4] Further examples of radio frequency cable trap assemblies are shown. [Figure 5] An example of a cable with a radio frequency cable trap assembly is shown. [Figure 6] Figure 5 shows an example of a coil connected to an illustrative cable. [Figure 7] Figure 6 shows an example of a magnetic resonance imaging system with a coil. [Figure 8] Further examples of radio frequency cable trap assemblies with inductive coupling are shown. [Figure 9] Figure 8 shows the functional behavior of the radio frequency cable trap assembly. [Figure 10] Further examples of radio frequency cable trap assemblies with capacitive coupling are shown. [Figure 11] Figure 10 shows the functional behavior of the radio frequency cable trap assembly. [Figure 12] An example of a radio frequency cable trap assembly with a battery unit is shown. [Figure 13] Further examples of radio frequency cable trap assemblies with battery units are shown. [Figure 14] Further examples of magnetic resonance imaging systems are shown. [Figure 15] Further examples of magnetic resonance imaging systems are shown. [Modes for carrying out the invention]

[0084] Elements with similar numbering in these diagrams are either equivalent elements or perform the same function. Elements mentioned above are not necessarily explained in later diagrams if their function is equivalent.

[0085] Figure 1 shows an exemplary radio frequency cable trap assembly 100. The radio frequency cable trap assembly 100 comprises a radio frequency cable trap circuit 102 and an indicator circuit 104. The radio frequency cable trap circuit 102 is configured to suppress the induction of AC energy in a cable at a predetermined magnetic resonance imaging operating frequency. The cable may be, for example, a cable for the magnetic resonance imaging coils of an MRI system. The indicator circuit 104 has an output unit 111 configured to output an indicator signal when a predetermined upper threshold is reached by the suppressed energy. To output the indicator signal, the indicator circuit 104 uses a portion of the suppressed energy transmitted from the radio frequency cable trap circuit 102 to the indicator circuit 104 via an energy transfer coupling between the radio frequency cable trap circuit 102 and the indicator circuit 104. The coupling may be, for example, an inductive or capacitive coupling. The transmitted portion of the suppressed energy may be used, for example, by an energy harvesting circuit 106 of the indicator circuit to provide energy to operate the output unit 111. The energy harvesting circuit 106 is configured to recover the portion of energy that has been suppressed due to the output of the instruction signal.

[0086] The instruction signal may be output in the form of, for example, a visual signal, an acoustic signal, and / or a radio signal. To output the instruction signal, the output unit 111 may have, for example, one or more of the following: a visual signal transmitting circuit 112 configured to emit a visual signal, an acoustic signal transmitting circuit 114 configured to emit an acoustic signal, and a radio signal transmitting circuit 116 configured to transmit a radio signal. The visual signal transmitting circuit 112 may have, for example, one or more LEDs. The acoustic signal transmitting circuit 114 may have, for example, a buzzer or a loudspeaker. The radio signal transmitting circuit 116 may have, for example, a radio frequency transmitter. The radio frequency transmitter may be configured to transmit a radio signal in a radio frequency band that can be received by, for example, a receiver component of an MRI system configured to receive MR radio frequency signals. The radio frequency transmitter may be configured as, for example, an RFID chip. The RFID chip may be configured to transmit a radio frequency signal that can be received by a dedicated receiver. The radio frequency transmitter may be configured to transmit a Bluetooth (LE) signal that can be received by, for example, a Wi-Fi signal or a remote router addressed by the transmitted signal.

[0087] Figure 2 shows another exemplary radio frequency cable trap assembly 100. The radio frequency cable trap assembly 100 in Figure 2 corresponds to the radio frequency cable trap assembly 100 in Figure 1. The only difference is that the radio frequency cable trap assembly 100 in Figure 2 has a battery unit 108 configured to supply energy for the output of a directional signal by the output unit 111, instead of an energy harvesting circuit. According to an alternative embodiment (not shown), the energy harvesting circuit 106 of the radio frequency cable trap assembly 100 in Figure 1 may be combined with the battery unit 108 of the radio frequency cable trap assembly 100 in Figure 2. In that case, energy may be supplied, for example, by energy harvesting using the battery unit 108 and the energy harvesting circuit 106 for the output of a directional signal by the output unit 111.

[0088] The output unit 111 may enter sleep mode to conserve energy. The portion of the suppressed energy being transmitted may control the passive switch 110. When the suppressed energy reaches a predetermined upper threshold, the portion of the suppressed energy being transmitted may be large enough to enable the passive switch and thereby activate the battery-powered output unit 111. Thus, the output mode of the instruction circuit 104, which outputs an instruction signal using the battery-powered output unit 111, may be activated in response to the suppressed energy in the radio frequency cable trap 102 reaching a predetermined upper threshold. A voltage exceeding a predetermined activation threshold supplied to the trigger pin of the output unit 111 may activate the unit and put it into active mode. In active mode, the output unit 111 may output an instruction signal with significantly higher power consumption than in sleep mode. For example, the comparator may consist of the instruction circuit 104 configured to compare a parameter describing the portion of the transmitted suppressed energy, e.g., voltage, with a reference parameter describing the reaching of a predetermined upper threshold, e.g., a reference voltage. The indicator circuit 104 may be configured to activate the output mode of the output unit 111 when it determines, using a comparator, that the suppressed energy has reached a predetermined upper threshold.

[0089] Figure 3 shows another exemplary radio frequency cable trap assembly 100. The radio frequency cable trap assembly 100 in Figure 3 corresponds to the radio frequency cable trap assembly 100 in Figure 1. The radio frequency cable trap assembly 100 in Figure 3 further includes a microcontroller unit 118 and one or more sensor circuits 120 for acquiring sensor data. The microcontroller may be configured, for example, to control the acquisition of sensor data using one or more sensor circuits 120 and to transmit the acquired sensor data via instruction signals in the form of radio signals using a radio signal transmission circuit 116 of an output unit 111. One or more sensor circuits 120 may be configured to acquire sensor data from, for example, one or more of the following parameters: namely, the temperature of the radio frequency cable trap assembly, i.e., the temperature of the radio frequency cable trap circuit 102 and / or the indicator circuit 104; the voltage of the radio frequency cable trap circuit 102 resulting from the suppressed energy; the voltage of the indicator circuit 104 resulting from the suppressed energy transmission portion; the current in the radio frequency cable trap circuit 102 resulting from the suppressed energy transmission portion; the current in the indicator circuit 104 resulting from the suppressed energy transmission portion; the magnetic field strength; ambient temperature; and ambient humidity.

[0090] Figure 4 shows another exemplary radio frequency cable trap assembly 100. The radio frequency cable trap assembly 100 in Figure 4 corresponds to the radio frequency cable trap assembly 100 in Figure 2. The radio frequency cable trap assembly 100 in Figure 4 further includes a microcontroller unit 118 and one or more sensor circuits 120 for acquiring sensor data. The microcontroller may be configured, for example, to control the acquisition of sensor data using one or more sensor circuits 120 and to transmit the acquired sensor data via instruction signals in the form of radio signals using a radio signal transmission circuit 116 of an output unit 111. One or more sensor circuits 120 may be configured to acquire sensor data from, for example, one or more of the following parameters: namely, the temperature of the radio frequency cable trap assembly, i.e., the temperature of the radio frequency cable trap circuit 102 and / or the indicator circuit 104; the voltage of the radio frequency cable trap circuit 102 resulting from the suppressed energy; the voltage of the indicator circuit 104 resulting from the suppressed energy transmission portion; the current in the radio frequency cable trap circuit 102 resulting from the suppressed energy transmission portion; the current in the indicator circuit 104 resulting from the suppressed energy transmission portion; the magnetic field strength; ambient temperature; and ambient humidity.

[0091] Figure 5 shows an exemplary cable 200. The cable 200 has or is provided with a radio frequency cable trap assembly 100. The radio frequency cable trap assembly 100 may be configured as, for example, one of the exemplary radio frequency cable trap assemblies 100 shown in Figures 1 to 4. The cable 200 may be, for example, a cable for a magnetic resonance imaging coil used in an MRI system. For example, the cable 200 may be a coaxial cable. The connection to the receiving coil may have, for example, several coaxial cables, as well as wires for power and (e.g., detuning) control lines. These components of the connection to the receiving coil may have external shielding, but are not required. For example, multiple traps may be arranged along the cable, depending on the frequency, i.e., distance well below half the free-space wavelength.

[0092] Figure 6 shows an exemplary magnetic resonance imaging coil 302 equipped with, i.e., connected to, the cable 200 of Figure 5, which has a radio frequency cable trap assembly 100. The magnetic resonance imaging coil 302 may be, for example, any receiving coil of an MRI system, particularly a flexible, arranged surface receiving coil.

[0093] Figure 7 shows an exemplary magnetic resonance imaging system 300 having a magnetic resonance imaging coil 302 of Figure 6 connected to a cable 200 having a radio frequency cable trap assembly 100. The magnetic resonance imaging system 300 may further have a receiver component 350 configured to receive instruction signals transmitted by the output unit of the instruction circuit of the radio frequency cable trap assembly 100. The receiver component 350 may be, for example, a receiving radio frequency coil of the magnetic resonance imaging system 300 configured to receive MR signals within the MR bandwidth. The receiver component 350 may be a dedicated receiver configured to receive instruction signals transmitted in the form of RFID signals. The receiver component 350 may be a remote router configured to receive instruction signals transmitted in the form of radio signals, for example, via WIFI, Bluetooth (LE) or any other power-efficient wireless communication method. The remote router may be configured to forward instruction signals to, for example, a controller of the magnetic resonance imaging system 300 or a remote server. For example, the remote server may forward instruction signals to the controller of the magnetic resonance imaging system 300.

[0094] Figure 8 shows an exemplary radio frequency cable trap assembly 100 for a cable 200 having a radio frequency cable trap circuit 102 and an indicator circuit 104. The cable is shown below, including a path through L1 which forms a coil inductor connected in parallel with C1. The voltage supply indicates excitation via a transmitting coil in an MRI system. The radio frequency cable trap circuit 102 has, for example, a loop-shaped inductance L1, a capacitor C1, and a resistor R1 which inductively couples to the pickup loop L2 of the indicator circuit 104 via a local magnetic field. In the example in Figure 8, for illustrative purposes, the following values ​​are used, namely, R1 = 0.1 Ω, R2 = 1 kΩ, R3 = 50 Ω, C1 = 61.85 pF, C2 = 100 nF, L1 = 100 nH, L2 = 100 nH, k = 0.01 (coupling between L1 and L2). Graph A in Figure 9 shows the suppression of AC current in cable 200 measured by Pr1 at a frequency of 64 MHz, i.e., a Larmor frequency of 1.5 T. The frequency varied from 54 MHz to 74 MHz. Graph B in Figure 9 shows the power absorbed by the radio frequency cable trap circuit 102 P = 0.5 * R1 * Pr2.I^2, where Pr2.I is the AC current measured by Pr2. Different B1 amplitudes, i.e., parameter sweeps for different parameters relative to V1, are shown. The voltage at the harvesting coil L2 shown in Graph C in Figure 9, plotting the harvesting voltage Pr3.dV measured by Pr3 against the high absorbed power P, becomes large enough to energy harvest and power the unit, for example, to transmit data to an MRI system.

[0095] Figure 10 shows an exemplary radio frequency cable trap assembly 100 for a cable 200 having a radio frequency cable trap circuit 102 and an indicator circuit 104. The voltage supply indicates excitation via a transmitting coil in an MRI system. In contrast to the inductive coupling between the radio frequency cable trap circuit 102 and the indicator circuit 104 of the radio frequency cable trap assembly 100 in Figure 8, the radio frequency cable trap circuit 102 and the indicator circuit 104 of the radio frequency cable trap assembly 100 in Figure 10 are inductively coupled via capacitors C3 and C4. Capacitive coupling may be implemented, for example, by a lumped capacitor or by placing the lower capacitor C5 near the upper capacitor C1 of the radio frequency cable trap circuit 102. Here, capacitor C1 is slightly reduced because capacitive coupling slightly detunes the resonance. In the example in Figure 10, for illustrative purposes, the following values ​​are used: R1 = 0.1 Ω, R2 = 1 kΩ, R3 = 50 Ω, C1 = 61.3 pF, C2 = 100 nF, C3 = 1 pF, C4 = 1 pF, C5 = 50 pF, and L1 = 100 nH. Graph A in Figure 11 shows the suppression of the AC current in cable 200 measured by Pr1 at a frequency of 64 MHz, i.e., a Larmor frequency of 1.5 T. The frequency varied from 54 MHz to 74 MHz. Graph B in Figure 11 shows the power absorbed by the radio frequency cable trap circuit 102 P = 0.5 * R1 * Pr2.I^2, where Pr2.I is the AC current measured by Pr2. Different B1 amplitudes, i.e., parameter sweeps for different parameters relative to V1, are shown. The voltage at the harvesting coil L2, shown in Graph C of Figure 11, plotting the harvesting voltage Pr3.dV measured by Pr3 against the high absorbed power P, becomes large enough to power the unit for energy harvesting and, for example, transmitting data to an MRI system.

[0096] Figure 12 shows an exemplary radio frequency cable trap assembly 100 having a battery unit 108. The radio frequency cable trap assembly 100 includes a radio frequency cable trap circuit 102 and an indicator circuit 104. The radio frequency cable trap assembly 100 is configured to transfer energy from the radio frequency cable trap circuit 102 to the indicator circuit 104 via an inductive energy transfer coupling. The indicator circuit 104 has a passive switch 110 controlled by a portion of the suppressed energy transferred from the radio frequency cable trap circuit 102 to the indicator circuit 104 via the inductive energy transfer coupling. When the transferred energy becomes large enough to enable the passive switch 110, the switch 110 activates an output mode of the indicator circuit 104 to output an indicator signal using an output unit 111. For example, the transferred energy may be large enough to enable the passive switch when it reaches a predetermined upper threshold. The output unit 111 may be powered by the battery unit 108. For example, an output unit 111, which may have a microcontroller unit, can be in a sleep mode with low power consumption, allowing the output unit 111 to remain passive for a long period, for example, many years. A voltage resulting from transmitted energy exceeding a predetermined activation threshold supplied to a trigger pin can activate the output unit 111, putting it into active mode, i.e., output mode. Once in output mode, the output unit 111 can output an instruction signal that consumes power supplied by the battery unit 108. For example, energy harvesting and battery-driven operation may be combined, and in normal operation, energy harvesting may be configured to recharge the battery unit, which may consume only a small amount of energy over time with no impact on normal operation, i.e., no backlash, and then, when a threshold is reached, the switch 110 can trigger the necessary action driven from the charged battery unit.

[0097] The instruction signal may be output by a battery-powered output unit 111 in the form of, for example, a visual signal, an acoustic signal, and / or a radio signal. To output the instruction signal, the output unit 111 may have one or more of the following: a visual signal emitting circuit configured to emit a visual signal, an acoustic signal emitting circuit configured to emit an acoustic signal, and a radio signal transmitting circuit configured to transmit a radio signal. The visual signal emitting circuit may have, for example, one or more LEDs. The acoustic signal emitting circuit may have, for example, a buzzer or a loudspeaker. The radio signal transmitting circuit may have, for example, a radio frequency transmitter. The radio frequency transmitter may be configured to transmit a radio signal in a radio frequency band that can be received by, for example, a receiver component of an MRI system configured to receive MR radio frequency signals. The radio frequency transmitter may be, for example, a crystal oscillator. The radio frequency transmitter may be configured as, for example, an RFID chip. The RFID chip may be configured to transmit a radio frequency signal that can be received by a dedicated receiver. The radio frequency transmitter may be configured to transmit a Wi-Fi signal or Bluetooth (LE) signal that can be received by, for example, a remote router addressed by the transmitted signal.

[0098] Figure 13 shows another exemplary radio frequency cable trap assembly 100 having a battery unit 108. The radio frequency cable trap assembly 100 has a radio frequency cable trap circuit 102 and an indicator circuit 104. The radio frequency cable trap assembly 100 is configured to transfer energy from the radio frequency cable trap circuit 102 to the indicator circuit 104 via a capacitive energy transfer coupling. The indicator circuit 104 has a passive switch 110 controlled by a portion of the suppressed energy transferred from the radio frequency cable trap circuit 102 to the indicator circuit 104 via the capacitive energy transfer coupling. When the transferred energy becomes large enough to enable the passive switch 110, the switch 110 activates an output mode of the indicator circuit 104 to output an indicator signal using an output unit 111. For example, the transferred energy may be large enough to enable the passive switch when it reaches a predetermined upper threshold. The output unit 111 may be powered by the battery unit 108. For example, an output unit 111, which may have a microcontroller unit, can be in a low-power-consuming sleep mode, allowing the output unit 111 to remain passive for a long period, such as many years. A voltage resulting from transmitted energy exceeding a predetermined activation threshold supplied to the trigger pin can activate the output unit 111, putting it into active mode, i.e., output mode. Once in output mode, the output unit 111 can output an instruction signal that consumes power supplied by the battery unit 108.

[0099] The instruction signal may be output by a battery-powered output unit 111 in the form of, for example, a visual signal, an acoustic signal, and / or a radio signal. To output the instruction signal, the output unit 111 may have one or more of the following: a visual signal transmitting circuit configured to emit a visual signal, an acoustic signal transmitting circuit configured to emit an acoustic signal, and a radio signal transmitting circuit configured to transmit a radio signal. The visual signal transmitting circuit may have, for example, one or more LEDs. The acoustic signal transmitting circuit may have, for example, a buzzer or a loudspeaker. The radio signal transmitting circuit may have, for example, a radio frequency transmitter. The radio frequency transmitter may be configured to transmit a radio signal in a radio frequency band that can be received by, for example, a receiver component of an MRI system configured to receive MR radio frequency signals. The radio frequency transmitter may be configured as, for example, an RFID chip. The RFID chip may be configured to transmit a radio frequency signal that can be received by a dedicated receiver. The radio frequency transmitter may be configured to transmit a WIFI signal or Bluetooth (LE) signal that can be received by, for example, a remote router addressed by the transmitted signal.

[0100] Figure 14 shows an example of a magnetic resonance imaging system 300 controlled by a computer 400. The magnetic resonance imaging system 300 has a magnet 304. The magnet 304 is a cylindrical superconducting magnet having a bore 306 through it. Different types of magnets can also be used; for example, both segmented cylindrical magnets and so-called open magnets can be used.

[0101] Within the bore 306 of the cylindrical magnet 304, there is an imaging zone 308 where the magnetic field is strong and uniform enough to perform magnetic resonance imaging. The region of interest 309 is shown within the imaging zone 308. The acquired magnetic resonance data is typically obtained for the region of interest 309. The subject 318 is shown being supported by the subject support 320 such that at least a portion of the subject 318 is within the imaging zone 308 and the region of interest 309.

[0102] Within the magnet's bore 306, there is also a set of magnetic gradient coils 310, which are used to acquire preliminary magnetic resonance data for spatial coding magnetic spins within the imaging zone 308 of the magnet 304. The magnetic gradient coils 310 are connected to a magnetic gradient coil power supply 312. The magnetic gradient coils 310 are intended to be illustrative. Typically, the magnetic gradient coils 310 include three separate sets of coils for spatial coding in three orthogonal spatial directions. The magnetic gradient power supply 312 supplies current to the magnetic gradient coils 310. The current supplied to the magnetic gradient coils 310 is controlled as a function of time and may be ramped or pulsed.

[0103] Adjacent to the imaging zone 308 is a radio frequency coil 314 for manipulating the orientation of magnetic spins within the imaging zone 308 and receiving radio transmissions from spins within the imaging zone 308. The radio frequency coil 314 may include multiple coil elements. The radio frequency coil 314 may also be referred to as an antenna. The radio frequency coil 314 is connected to a radio frequency transceiver 316, for example, via a cable 200. The cable 200 may have, for example, a radio frequency cable trap assembly 100 having a radio frequency cable trap circuit and an indicator circuit. The radio frequency coil 314 and the radio frequency transceiver 316 may be replaced, for example, with separate transmitting and receiving coils, and separate transmitters and receivers. Alternatively, one or more receiving coils connected to a radio frequency receiver via a cable may be comprised of the magnetic resonance imaging system 300 in addition to the illustrated radio frequency coil 314 and transceiver 316. The radio frequency coil 314 and the radio frequency transceiver 316 are understood to be representative. The radio frequency coil 314 is also intended to represent a dedicated transmitting antenna and a dedicated receiving antenna. Similarly, the transceiver 316 may represent separate transmitters and receivers. The radio frequency coil 314 may have multiple receiving / transmitting elements, and the radio frequency transceiver 316 may have multiple receiving / transmitting channels. For example, when a parallel imaging technique such as SENSE is performed, the radio frequency coil 314 has multiple coil elements.

[0104] The instruction signal output by the radio frequency cable trap assembly may be output as a radio signal at a radio frequency within the MR bandwidth, which is received, for example, by the radio frequency coil 314 of the magnetic resonance imaging system 300, for example, by another receiving coil. For example, the magnetic resonance imaging system 300 may have a dedicated receiver 350 configured to receive the instruction signal transmitted in the form of an RFID signal. The dedicated receiver 350 may be located, for example, in the target support 320, in the bore 306, or elsewhere in the RF shield room. For example, the receiver may be provided in the form of a remote router configured to receive the instruction signal transmitted in the form of a radio signal, for example via WIFI, Bluetooth (LE), or any other power-efficient wireless communication method. The remote router may be configured to forward the instruction signal to, for example, a computer 400 or remote server that controls the magnetic resonance imaging system 300. For example, the remote server may forward the instruction signal to the computer 400 of the magnetic resonance imaging apparatus 300.

[0105] The transceiver 316 and the gradient controller 312 are shown as being connected to the hardware interface 406 of the computer 400.

[0106] Computer 400 is intended to represent one or more computing devices. Computer 400 is configured to acquire medical imaging data as part of the control system of the magnetic resonance imaging system 300. Computer 400 is shown as having a computing system 404. Computing system 404 is intended to represent one or more processors, processing cores, or other computing systems located in one or more locations. Computing system 404 is shown as being connected to an optional hardware interface 406, a user interface 408, and memory 410. If other components are present, the hardware interface 406 may allow computing system 404 to exchange commands and data with those other components.

[0107] An optional hardware interface 406 may enable, for example, the computing system 404 to control other components, such as the magnetic resonance imaging system 300. The computing system 404 is further shown as being connected to an optional user interface 408, which enables, for example, an operator to control and operate the computer 400 and control and operate the magnetic resonance imaging system 300 via the computer 400. The optional user interface 408 may have, for example, output and / or input devices that enable a user to interact with the computer 400. The output device may have a display device configured to display magnetic resonance imaging and / or instruction data 428, which consists of instruction signals received from the output unit of the radio frequency cable trap assembly 100. The input device may have, for example, a keyboard and / or mouse that enables a user to control the computer 400 and insert control commands to control the magnetic resonance imaging system 300 via the computer 400. The computing system 404 is further shown as being connected to memory 410. Memory 410 is intended to represent different types of memory that can be connected to the computing system 404, and may be, for example, a non-temporary storage medium.

[0108] The memory is shown as containing machine-executable instructions 420. The machine-executable instructions 420 enable the computing system 404 to perform tasks such as controlling other components to perform numerical tasks, as well as performing various data and image processing tasks. The machine-executable instructions 420 may, for example, enable the computing system 404 to control the magnetic resonance imaging system 300. For example, the machine-executable instructions 420 may be configured to stop an MRI scan being performed by the magnetic resonance imaging apparatus 300 in response to receiving an instruction signal 428 from the output unit of the radio frequency cable trap assembly 100.

[0109] Memory 410 is further shown as containing pulse sequence commands 422. Pulse sequence commands 422 are commands or data that can be translated into commands configured to control the magnetic resonance imaging system 300 to acquire magnetic resonance imaging data 424 from region of interest 309. The acquired magnetic resonance imaging data 424 is used to reconstruct the magnetic resonance image 426.

[0110] Memory 410 is further described as being provided by a received instruction signal and containing instruction data 428 indicating that a predetermined upper limit threshold has been reached due to the suppressed energy in the radio frequency cable trap assembly 100. The instruction data 428 may be processed and / or stored by a computer 400. The instruction signal may be received from an output unit of the radio frequency cable trap assembly 100. Upon receipt of the instruction signal, the instruction data 428 transmitted by the instruction signal may be processed by a computing system 404, which may, for example, automatically stop the MRI scan being performed by the magnetic resonance imaging system 300 upon receipt of the instruction data 428. The instruction data 428 provided by the received instruction signal may include additional information, such as sensor data acquired by sensors of the radio frequency cable trap assembly 100.

[0111] Figure 15 shows another example of the magnetic resonance imaging system 300. The magnetic resonance imaging system 300 in Figure 15 corresponds to the magnetic resonance imaging system 300 in Figure 14, with the radio frequency coils and transceivers replaced by separate transmitting coils 311 and receiving coils 317, and separate transmitters 313 and receivers 317. The array of receiving coils 317 is connected to the receiver 315, for example, via a cable 200. The cable 200 may have, for example, one or more radio frequency cable trap assemblies 100 having radio frequency cable trap circuits and indicator circuits. Such traps 100 may be particularly useful where the B1 magnetic field from the transmitting coil 311 is acquired, i.e., within the bore 306. A first trap may also be located, for example, inside the receiving coil 317. The coils 317 may be configured, for example, for locally flexible placement. For example, the receiving coils 317 may be located near or directly above the target 318. Similar to the receiving coil 317, the transmitting coil 311 may include multiple coil elements and may be implemented, for example, in the form of an array of coils. The receiver 315 and transmitter 313 are shown as being connected to the hardware interface 406 of the computer 400.

[0112] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustrations and descriptions should be considered descriptive or illustrative and not limiting. The present invention is not limited to the disclosed embodiments.

[0113] Other modifications of the disclosed embodiments can be understood and implemented by those skilled in the art in carrying out the claimed inventions, from a consideration of the drawings, disclosures, and appended claims. In the claims, the words “comprising” do not exclude other components or steps, and the indefinite articles “a” or “an” do not exclude plurality. A single processor or other unit can perform the functions of several items enumerated in the claims. The mere fact that certain means are described in different dependent claims does not imply that combinations of these means cannot be used advantageously. Computer programs can be stored / distributed on suitable media such as optical or solid-state media supplied together with or as part of other hardware, but they can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. No reference numerals in the claims should be construed as limiting in scope. The embodiments of the present invention are described below. (Note 1) A cable for a magnetic resonance imaging coil includes a radio frequency cable trap configured to suppress the induction of AC energy at a predetermined magnetic resonance imaging operating frequency, An instruction circuit comprising an output unit configured to output an instruction signal when a predetermined upper limit threshold is reached by the suppressed energy, using a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the instruction circuit via an energy transfer coupling between the radio frequency cable trap circuit and the instruction circuit, the instruction circuit comprising an energy harvesting circuit configured to harvest the portion of the suppressed energy transmitted via the energy transfer coupling, and the instruction circuit configured to use the harvested energy for outputting the instruction signal, A radio frequency cable trap assembly having the following features. (Note 2) The instruction circuit has a passive switch that is controlled by the portion of the suppressed energy transmitted via the energy transfer coupling, and is configured to activate an output mode of the instruction circuit to output the instruction signal when the suppressed energy reaches a predetermined upper threshold, or The instruction circuit has a comparator configured to compare a parameter describing the suppressed portion of energy transmitted via the energy transfer coupling with a reference parameter describing the reaching of a predetermined upper threshold, and the instruction circuit is configured to activate the output mode when it determines, using the comparator, that the suppressed energy has reached the predetermined upper threshold. The radio frequency cable trap assembly described in Appendix 1. (Note 3) The energy transfer coupling is an inductive coupling, or The energy transfer coupling is a capacitive coupling. A radio frequency cable trap assembly as described in either Appendix 1 or 2. (Note 4) The radio frequency cable trap assembly according to any one of appendices 1 to 3, wherein the instruction circuit has a battery unit configured to supply energy for the output of the instruction signal. (Note 5) A radio frequency cable trap assembly according to any one of appendices 1 to 4, wherein the instruction signal includes a visual signal, and the output unit has a visual signal emitting circuit configured to emit the visual signal. (Note 6) The radio frequency cable trap assembly according to any one of appendices 1 to 5, wherein the instruction signal includes an acoustic signal, and the output unit has an acoustic signal emitting circuit configured to emit an acoustic signal. (Note 7) A radio frequency cable trap assembly according to any one of appendices 1 to 6, wherein the instruction signal includes a radio signal, and the output unit has a radio signal transmission circuit configured to transmit the radio signal. (Note 8) The instruction circuit is configured to transmit the radio signal in a radio frequency band that at least partially overlaps with a predetermined magnetic resonance imaging operating frequency band including the predetermined magnetic resonance imaging operating frequency, or The instruction circuit is configured to transmit the radio signal in a radio frequency band outside the predetermined magnetic resonance imaging operating frequency band. The radio frequency cable trap assembly described in Appendix 8. (Note 9) The instruction circuit comprises one or more sensor circuits for acquiring sensor data, and a microcontroller for controlling the acquisition of the sensor data and the transmission of the acquired sensor data by a wireless signal, as described in any one of Appendix 8 to 9 of the radio frequency cable trap assembly. (Note 10) The one or more sensor circuits described above have the following parameters: - The temperature of the radio frequency cable trap assembly, - Voltage in the radio frequency cable trap circuit resulting from the suppressed energy, - The voltage in the indicator circuit resulting from the transmitted portion of the suppressed energy, - The current in the radio frequency cable trap circuit resulting from the suppressed energy, - Current in the indicator circuit arising from the transmitted portion of the suppressed energy, - Magnetic field strength, - environmental temperature, - environmental humidity, A radio frequency cable trap assembly as described in Appendix 9, configured to acquire one or more of the sensor data. (Note 11) The radio frequency cable trap assembly according to any one of appendices 7 to 10, wherein the transmitted radio signal includes an ID of the radio frequency cable trap assembly that identifies the radio frequency cable trap assembly transmitting the radio signal. (Note 12) A cable for a magnetic resonance imaging coil having a radio frequency cable trap assembly as described in any one of Appendix 1 to 10. (Note 13) A magnetic resonance imaging coil having the cable described in Appendix 12. (Note 14) A magnetic resonance imaging system having a magnetic resonance imaging coil as described in Appendix 13. [Explanation of symbols]

[0114] 100 Radio Frequency Cable Trap Assembly 102 Radio frequency cable trap circuit 104 Indication circuit 106 Energy Harvesting Circuit 108 Battery Units 110 switches 111 Output Unit 112 Visual signal transmission circuit 114 Acoustic signal generation circuit 116 Wireless signal transmission circuit 118 Microcontroller Unit 120 Sensor Circuit 200 Cables 300 Magnetic Resonance Imaging System 302 Coil 304 Magnet 306 Magnet Bore 308 imaging zones 309 Areas of Interest 310 Magnetic field gradient coil 311 Radio frequency transmitting coil 312 Magnetic Field Gradient Coil Power Supply 313 Transmitter 314 Radio frequency coil 315 Receiver 316 Transceiver 317 Radio frequency receiving coil 318 Targets 320 Target Support 350 Receiver Components 400 Computers 404 Computing System 406 Optional Hardware Interface 408 Optional User Interface 410 memory 420 Machine-Executable Instructions 422 Pulse Sequence Command 424 Magnetic Resonance Imaging Data 426 Magnetic Resonance Images 428 Instruction Data

Claims

1. A cable for a magnetic resonance imaging coil includes a radio frequency cable trap circuit configured to suppress the induction of AC energy at a predetermined magnetic resonance imaging operating frequency, An instruction circuit comprising an output unit configured to output an instruction signal when a predetermined upper limit threshold is reached by the suppressed energy, using a portion of the suppressed energy transmitted from the radio frequency cable trap circuit to the instruction circuit via an energy transfer coupling between the radio frequency cable trap circuit and the instruction circuit, the instruction circuit comprising an energy harvesting circuit configured to harvest the portion of the suppressed energy transmitted via the energy transfer coupling, and the instruction circuit configured to use the harvested energy for outputting the instruction signal, A radio frequency cable trap assembly having the following features.

2. The instruction circuit has a passive switch that is controlled by the portion of the suppressed energy transmitted via the energy transfer coupling, and is configured to activate an output mode of the instruction circuit to output the instruction signal when the suppressed energy reaches a predetermined upper threshold, or The instruction circuit has a comparator configured to compare a parameter describing the suppressed portion of energy transmitted via the energy transfer coupling with a reference parameter describing the reaching of a predetermined upper threshold, and the instruction circuit is configured to activate the output mode when it determines, using the comparator, that the suppressed energy has reached the predetermined upper threshold. The radio frequency cable trap assembly according to claim 1.

3. The energy transfer coupling is an inductive coupling, or The energy transfer coupling is a capacitive coupling. A radio frequency cable trap assembly according to either claim 1 or 2.

4. The radio frequency cable trap assembly according to claim 1 or 2, wherein the instruction circuit has a battery unit configured to supply energy for the output of the instruction signal.

5. The radio frequency cable trap assembly according to claim 1 or 2, wherein the instruction signal includes a visual signal, and the output unit has a visual signal emitting circuit configured to emit the visual signal.

6. The radio frequency cable trap assembly according to claim 1 or 2, wherein the instruction signal includes an acoustic signal, and the output unit has an acoustic signal emitting circuit configured to emit an acoustic signal.

7. The radio frequency cable trap assembly according to claim 1 or 2, wherein the instruction signal includes a radio signal, and the output unit has a radio signal transmitting circuit configured to transmit the radio signal.

8. The instruction circuit is configured to transmit the radio signal in a radio frequency band that at least partially overlaps with a predetermined magnetic resonance imaging operating frequency band including the predetermined magnetic resonance imaging operating frequency, or The instruction circuit is configured to transmit the radio signal in a radio frequency band outside the predetermined magnetic resonance imaging operating frequency band. The radio frequency cable trap assembly according to claim 7.

9. The radio frequency cable trap assembly according to claim 7, wherein the instruction circuit comprises one or more sensor circuits for acquiring sensor data, and a microcontroller for controlling the acquisition of the sensor data and the transmission of the acquired sensor data by radio signals.

10. The one or more sensor circuits described above have the following parameters: - The temperature of the radio frequency cable trap assembly, - Voltage in the radio frequency cable trap circuit resulting from the suppressed energy, - The voltage in the indicator circuit resulting from the transmitted portion of the suppressed energy, - The current in the radio frequency cable trap circuit resulting from the suppressed energy, - Current in the indicator circuit arising from the transmitted portion of the suppressed energy, - Magnetic field strength, - environmental temperature, - environmental humidity, The radio frequency cable trap assembly according to claim 9, configured to acquire one or more of the sensor data.

11. The radio frequency cable trap assembly according to claim 7, wherein the transmitted radio signal includes an ID of the radio frequency cable trap assembly that identifies the radio frequency cable trap assembly transmitting the radio signal.

12. A cable for a magnetic resonance imaging coil having the radio frequency cable trap assembly according to claim 1 or 2.

13. A magnetic resonance imaging coil having the cable described in claim 12.

14. A magnetic resonance imaging system having a magnetic resonance imaging coil as described in claim 13.

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