Magnetic array and magnetic resonance device

Abstract

A magnet arrangement (11) for a magnetic resonance instrument (10), comprising: a superconducting magnet (12); a discharge system (35); a switch (37) which is designed to interrupt a closed circuit in the superconducting magnet (12) and to transfer electrical energy that has accumulated in the superconducting magnet (12) to the discharge system (35); wherein the discharge system (35) comprises a supercapacitor (30) which is configured to buffer a transfer of electrical energy from the superconducting magnet (12) to a discharge element in the discharge system (35).

Description

[0001] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0002] The present disclosure relates to a magnetic arrangement for a magnetic resonance device and in particular to a magnetic arrangement configured to discharge electrical energy from a superconducting magnet.

[0003] Magnetic resonance imaging (MRI) scanners are widely used in medical diagnostics to acquire images of a patient's internal body structures. These devices rely on superconducting magnets to generate the strong magnetic fields required for imaging. The superconducting magnets in MRI systems store large amounts of electrical energy in the form of a continuous current, which maintains the magnetic field during normal operation.

[0004] One of the main challenges in MRI technology is the safe handling of the electrical energy stored in the superconducting magnets, especially during planned shutdowns or unexpected power outages. When an MRI system needs to be shut down, whether for maintenance or in emergency situations, the electrical energy in the superconducting magnet must be dissipated quickly and safely. This process, known as "ramp-down," is crucial for protecting the magnet and surrounding equipment from damage. In MRI scanners where the superconducting magnets are stored in a bath of liquid cryogen, overheating of the superconducting magnets can also lead to a "quench," in which the liquid cryogen is rapidly vaporized and released into the environment.

[0005] Conventional methods for discharging superconducting magnets typically involve converting the stored electrical energy into heat using resistive elements or "discharge resistors." However, with the development of MRI systems to stronger magnetic fields, the amount of energy to be dissipated has increased. This can pose significant challenges in terms of thermal management, system design, and overall efficiency. The heat energy generated during a magnetic discharge can cause thermal stress in components of the MRI scanner and necessitate a dedicated cooling system, thereby increasing the complexity and cost of the MRI scanner.

[0006] Furthermore, the energy dissipated during magnetic discharge represents a significant resource loss. In modern healthcare facilities, where energy efficiency and sustainability are increasingly important, the inability to recover and reuse this energy is a growing concern. Additionally, the time required for the safe discharge and subsequent recharging of high-field superconducting magnets can lead to extended system downtime, negatively impacting patient care and operational efficiency in clinical settings.

[0007] It is therefore an object of the invention to improve magnetic discharge. In particular, it is an object of some aspects of the invention to reduce the requirements for a component involved in the magnetic discharge.

[0008] This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments and expedient further developments are the subject matter of the dependent claims.

[0009] The magnetic arrangement according to the invention for a magnetic resonance device comprises a superconducting magnet, a discharge system, and a switch configured to interrupt a closed circuit in the superconducting magnet and to transfer electrical energy accumulated in the superconducting magnet to the discharge system. The discharge system comprises a supercapacitor configured to buffer the transfer of electrical energy from the superconducting magnet to a discharge element in the discharge system.

[0010] The superconducting magnet can be designed to generate a strong and uniform magnetic field in an imaging area (or image acquisition area) of a magnetic resonance device.

[0011] The discharge system, in particular the discharge element, can be configured to receive electrical energy from the superconducting magnet during a ramp-down process. The discharge element can, for example, include a resistor element and / or a battery storage element. It is conceivable that the discharge system is configured to absorb and / or store the electrical energy from the superconducting magnet. It is further conceivable that the discharge element is configured to convert the electrical energy from the superconducting magnet into thermal energy.

[0012] The switch can be configured to control the flow of electrical energy between the superconducting magnet and the discharge system. Specifically, the switch can be configured to electrically connect the superconducting magnet to the discharge system depending on the switching state of the switch. Likewise, the switch can be configured to electrically disconnect the superconducting magnet from the discharge system depending on the switching state of the switch.

[0013] The supercapacitor can be designed to absorb a large amount of electrical energy from the superconducting magnet and store it, at least temporarily. For example, the supercapacitor can have an energy density between 0.1 and 20 Wh / kg. It is conceivable that the energy density of the supercapacitor is a fraction, for example, 5% to 15%, of the energy density of a battery storage system. In contrast, the supercapacitor can have a power density that exceeds that of a battery storage system by up to ten or even one hundred times.

[0014] The magnet arrangement according to the invention can enable a more efficient and controlled discharge of the superconducting magnet. In particular, the use of a supercapacitor can allow for faster absorption of the electrical energy from the superconducting magnet, thereby advantageously reducing the time required to shut down the magnet. The supercapacitor can advantageously help to buffer sudden energy surges in the discharge system. The buffering effect of the supercapacitor reduces the requirements for the discharge element with regard to the absorption and handling of electrical energy from the superconducting magnet. This advantageously reduces costs and / or the installation space required for the discharge element.

[0015] According to one embodiment of the magnetic arrangement according to the invention, the discharge system comprises a resistive element. The supercapacitor is configured to receive and store electrical energy from the superconducting magnet and to transfer the electrical energy to the resistive element.

[0016] Preferably, the resistive element is configured to convert electrical energy into thermal energy and dissipate it to the environment. The resistive element can comprise materials with high thermal conductivity, such as aluminum or copper. It is also conceivable that the resistive element has a heat transfer surface configured to transfer thermal energy from the resistive element to a surrounding medium. For example, the resistive element can be configured to transfer thermal energy to the surrounding air.

[0017] The supercapacitor can be designed to act as an intermediate energy storage device and to enable a more even feed of electrical energy into the resistive element.

[0018] A combination of a supercapacitor and a resistive element can enable more efficient thermal management during the shutdown of the superconducting magnet. Furthermore, the supercapacitor can buffer the input of electrical energy to the resistive element, reduce potential peak temperatures in the resistive element, and / or allow for a reduction or miniaturization of the required heat transfer surfaces. Compared to conventional magnetic resonance devices, a magnet arrangement according to the invention can also enable a more uniform and / or controlled dissipation of electrical energy from the superconducting magnet as heat energy.

[0019] According to one embodiment of the magnet arrangement according to the invention, the discharge system comprises a battery storage system. The supercapacitor is configured to receive and store electrical energy from the superconducting magnet and to supply the electrical energy to the battery storage system.

[0020] The battery storage system can be designed to store electrical energy for later use. It is conceivable that the battery storage system could include rechargeable batteries, such as lithium-ion batteries, alkaline manganese batteries, but also metal-ion batteries, metal-sulfur batteries, and / or metal-air batteries. The supercapacitor in this arrangement can be configured to absorb power spikes or the initial energy surge from the superconducting magnet and then gradually transfer it to the battery storage system.

[0021] A combination of a supercapacitor and a battery storage system can enable energy recovery during the discharge of the superconducting magnet. Using a supercapacitor as an intermediate storage device can advantageously protect the battery storage system from potentially damaging power spikes. Furthermore, the energy stored in the battery storage system can be used for future magnet start-up processes or for other purposes, thereby improving the overall efficiency of the system.

[0022] According to one embodiment of the magnet arrangement according to the invention, the discharge system comprises a conditioning unit which is configured to receive electrical energy from the superconducting magnet and / or the supercapacitor and to supply electrical energy to the battery storage system at a predetermined voltage.

[0023] The conditioning unit can be configured to adapt the voltage and current of the electrical energy to the requirements of the battery storage system. It can include power electronic components such as DC / DC converters or inverters. In particular, the conditioning unit can be configured to process a high initial current (e.g., a power surge) from the superconducting magnet or supercapacitor and convert it into a form suitable for the battery storage system. Preferably, the conditioning unit is configured to adjust a voltage and / or a current depending on the requirements of the battery storage system.

[0024] A magnetic arrangement according to the invention, comprising a conditioning unit and a battery storage system, can advantageously enable more efficient and safer charging of the battery storage system. The conditioning unit can help protect the batteries from overcharging or unsuitable voltage levels. Furthermore, the magnetic arrangement according to the invention can enable more flexible energy management and potentially allow the recovered energy to be used in various ways within the magnetic resonance device or the facility.

[0025] In a further embodiment, the discharge system of the magnetic arrangement according to the invention comprises a resistance element and a battery storage system. The supercapacitor is configured to receive and store electrical energy from the superconducting magnet and to release the electrical energy to the resistance element and / or the battery storage system.

[0026] By combining a resistive element and a battery storage system, the flexibility and efficiency of discharging the superconducting magnet can be advantageously increased. In particular, a combination of the resistive element and the battery storage system can enable both energy dissipation and energy recovery. The supercapacitor can act as a buffer and protect both the resistive element and the battery storage system from power spikes or sudden energy surges. Furthermore, a magnet arrangement according to the invention offers the possibility of safely dissipating the electrical energy from the superconducting magnet to the resistive element in the event of the battery storage system being unavailable (e.g., during a failure or maintenance).It is also conceivable that the dimensions and / or weight of the resistive element could be advantageously reduced, since some of the electrical energy from the superconducting magnet could be transferred to the battery storage system. This would allow for a beneficial reduction in both the installation space and costs associated with the magnet assembly.

[0027] According to one embodiment of the magnet arrangement according to the invention, the magnet arrangement further comprises a conditioning unit configured to receive electrical energy from the superconducting magnet and / or the supercapacitor and to supply electrical energy to the battery storage system at a predetermined voltage.

[0028] The conditioning unit can be configured according to an embodiment described above. Preferably, the conditioning unit is configured as a DC / DC converter.

[0029] Providing a conditioning unit can help to better protect the battery storage system from overcharging or unsuitable voltage levels. In particular, energy management in the discharge system can be advantageously made more flexible by means of a conditioning unit, and the proportion of electrical energy recovered from the superconducting magnet can be increased.

[0030] According to one embodiment of the magnetic arrangement according to the invention, the conditioning unit is designed to provide the battery storage system with electrical energy at a substantially constant current decay rate.

[0031] The conditioning unit can be configured to control the rate at which electrical energy is transferred to the battery storage system. It is conceivable that the conditioning unit is configured to implement and / or use control algorithms to maintain a constant current decay rate. In particular, the conditioning unit can be configured to adjust or set an output current in real time based on changing properties of the energy source (e.g., the superconducting magnet and / or the supercapacitor), as well as the battery storage system.

[0032] A magnetic arrangement according to the invention, including a conditioning unit, can enable improved or optimized charging of the battery storage system. In particular, a constant current drop rate can help to protect the battery storage system from stress and / or extend its service life. Furthermore, a conditioning unit according to an embodiment described above can enable a more uniform and / or efficient energy transfer to the battery storage system.

[0033] According to one embodiment of the magnetic arrangement according to the invention, the discharge system comprises a resistive element, wherein the supercapacitor is configured to receive and store electrical energy from the superconducting magnet and to deliver the electrical energy to the resistive element. The magnetic arrangement further comprises a cooling unit configured to cool the resistive element.

[0034] The resistive element can be configured according to an embodiment described above. Preferably, the resistive element comprises or consists of a material with high thermal conductivity, such as aluminum or copper.

[0035] Preferably, the cooling unit is designed to actively dissipate heat energy from the resistance element. It is conceivable that the cooling unit is designed to dissipate heat energy from the resistance element by means of a cooling medium. The cooling medium can, in particular, comprise a fluid, for example, a gas or a liquid. The cooling unit can, for example, be designed as a fan or a blower. Furthermore, the cooling unit can comprise a conveying unit and a heat exchanger thermally coupled to the resistance element. The conveying unit can, for example, be designed as a pump, which is configured to transport a liquid cooling medium through the heat exchanger.

[0036] A magnet arrangement according to the invention, incorporating a cooling unit, advantageously allows for improved thermal management of the resistance element. Active cooling can, in particular, help to maintain the resistance element at a safe temperature and / or enable faster dissipation of heat energy to the environment. Furthermore, a cooling unit can allow the use of a smaller resistance element, thereby reducing the overall size and weight of the magnet arrangement.

[0037] According to one embodiment of the magnetic arrangement according to the invention, the switch comprises a superconducting element which is designed to maintain the closed circuit in the superconducting magnet when it is cooled below a superconducting temperature.

[0038] The superconducting element can comprise or consist of a superconducting material. Preferably, the superconducting element in the switch exhibits virtually no electrical resistance when cooled to a temperature below the critical temperature (or superconducting temperature) of the superconducting material. For example, the superconducting element can be made of a material such as niobium-titanium or niobium-tin. The superconducting element can be configured to allow a continuous current or a closed circuit in the superconducting magnet. In particular, the superconducting element can be configured to allow virtually lossless current flow during the normal operation of the superconducting magnet. For this purpose, the switch can be in a closed configuration or in a closed switching state.

[0039] An inventive magnetic arrangement with a switch according to an embodiment described above can advantageously enable efficient and loss-free operation of the superconducting magnet during normal use. The superconducting element of the switch can, in particular, ensure reliable maintenance of the closed circuit. Furthermore, a switch with a superconducting element allows for precise and / or robust control of the discharge of electrical energy from the superconducting magnet into the discharge system.

[0040] According to one embodiment, the magnetic arrangement according to the invention comprises a heating device which is designed to heat the superconducting element of the switch in response to a control signal.

[0041] The heating device can be configured to increase the temperature of the switch's superconducting element. It is conceivable that the heating device comprises a resistance heater or another heating element. Furthermore, the heating device can be configured to respond promptly to control signals and enable precise timing of the switch activation.

[0042] An inventive magnetic arrangement comprising a switch with a superconducting element and a heating device enables controlled initiation of the discharge of the superconducting magnet. By heating the superconducting element to a temperature above the critical temperature of the superconducting material, the switch can be opened, thereby diverting the current to the discharge system. This allows for a rapid response in emergency situations (e.g., a power outage) or during planned maintenance work and / or improves safety and operational flexibility.

[0043] According to one embodiment of the magnet arrangement according to the invention, the supercapacitor comprises a lithium-ion capacitor or consists of a lithium-ion capacitor.

[0044] A lithium-ion capacitor can combine features of both supercapacitors and lithium-ion batteries. Specifically, a lithium-ion capacitor can represent a hybrid electrochemical energy storage unit, combining the intercalation mechanism of a lithium-ion battery anode with the double-layer mechanism of a cathode from an electrical double-layer capacitor. For example, combining the negative lithium titanium oxide electrode of a lithium-ion battery with the positive activated carbon electrode of a capacitor can result in an energy density approximately four to five times that of a conventional electrical double-layer capacitor.

[0045] A lithium-ion capacitor can exhibit a higher energy density than conventional supercapacitors while simultaneously providing the high power density of conventional supercapacitors. The lithium-ion capacitor can achieve rapid charge and discharge cycles. Furthermore, the lithium-ion capacitor can be designed to absorb high electrical currents during the discharge of the superconducting magnet, while also providing a higher energy storage capacity compared to conventional supercapacitors.

[0046] A lithium-ion capacitor can enable improved energy absorption and / or storage during the discharge of the superconducting magnet. In particular, the use of a lithium-ion capacitor allows for more efficient energy recovery and management within the discharge system. Furthermore, due to its higher energy density compared to conventional supercapacitors, a lithium-ion capacitor can be advantageously designed with smaller physical dimensions, thus reducing the space required for the magnet assembly.

[0047] According to one embodiment of the magnet arrangement according to the invention, the superconducting magnet is designed to generate a magnetic field strength of at least 1.5 Tesla, at least 2 Tesla, at least 2.5 Tesla or at least 3 Tesla.

[0048] The superconducting magnet can be configured to generate a strong and homogeneous magnetic field. In one embodiment, the superconducting magnet comprises one or more superconducting magnetic coils. A magnetic coil can, in particular, have a solenoid or cylindrical shape. For example, the magnetic coils can be arranged concentrically offset along a common axis. The magnetic coils can at least partially enclose a cylindrically shaped imaging area or patient acquisition area along a circumferential direction.

[0049] Higher magnetic field strengths allow for the acquisition of higher-resolution images. However, an increase in magnetic field strength also increases the electrical energy stored in the superconducting magnet, and thus power spikes that can occur during the discharge of the superconducting magnet. By providing a discharge system with a supercapacitor, such power spikes can be advantageously buffered, reducing or preventing negative effects on the discharge element.

[0050] Especially in dry magnets, where the superconducting magnet is not stored in a bath of liquid cryogen, the electrical energy from the superconducting magnet must be dissipated to the discharge system as quickly as possible to prevent overheating of the superconducting magnet. For this purpose, the resistive element must be correspondingly large, which can cause practical problems with its placement. A magnet arrangement according to the invention with a supercapacitor advantageously allows for the reliable absorption of electrical energy even from superconducting magnets with higher magnetic field strengths, while also reducing the size of the resistive element.

[0051] The magnetic resonance device according to the invention is configured to perform a magnetic resonance measurement of an object positioned within an imaging area of ​​the magnetic resonance device. The magnetic resonance device comprises a magnet arrangement according to one of the embodiments described above.

[0052] Preferably, the magnetic resonance imaging device is designed to acquire magnetic resonance image data, in particular diagnostic magnetic resonance image data, from the object. The object can be an item or a patient, in particular a human being or an animal.

[0053] The magnetic resonance imaging device according to the invention can be a closed-bore scanner. A closed-bore scanner can comprise a substantially cylindrical patient tunnel or patient acquisition area. According to one embodiment described above, the magnetic arrangement of the closed-bore scanner can comprise a superconducting magnet with one or more superconducting magnetic coils that enclose the patient acquisition area along an axial direction or a rotational symmetry axis of the cylindrically shaped patient acquisition area. The superconducting magnet can comprise a superconducting wire that exhibits negligible electrical resistance at (or below) a superconducting temperature.One direction of a main magnetic field, which is provided by means of the superconducting magnet, can be essentially aligned parallel to an access direction of the object to the imaging area and / or the axial direction of the cylindrically designed patient reception area.

[0054] However, the magnetic resonance device according to the invention can also be designed as an open scanner, for example a C-type scanner, a dipolar scanner (e.g. with two opposing magnets), a single-sided scanner (e.g. with only one magnet) or the like.

[0055] The magnetic resonance device according to the invention may include further components that are necessary for the proper operation of the magnetic resonance device. For example, the magnetic resonance device may include an outer vacuum chamber, a magnetic support structure, a thermal shield, a cryocooler, a cryogen container, and the like.

[0056] According to one embodiment, the magnetic resonance imaging (MRI) device comprises an outer vacuum chamber that encloses the superconducting magnet. The outer vacuum chamber can be configured as a double-walled hollow cylinder. In particular, the outer vacuum chamber can comprise an outer shell and an inner shell connected by circular end pieces. The superconducting magnet can be enclosed between the outer shell and the inner shell of the outer vacuum chamber. The inner shell of the outer vacuum chamber can define the patient tunnel of the MRI device.

[0057] In some embodiments, the magnetic resonance device may include one or more cryogen containers. A cryogen container may be designed for the storage and / or preservation of a liquid, in particular a cryogen, at a predefined temperature level. Preferably, the liquid or cryogen has a low boiling point. Examples of suitable liquids or cryogens are argon, nitrogen, neon, helium, and the like. The predetermined temperature level may essentially correspond to a superconducting temperature of the main magnet.

[0058] A cryocooler can be configured according to an embodiment described above. The cryocooler can be designed to cool the superconducting magnet of the magnet assembly and / or to maintain the superconducting magnet at a temperature level close to the superconducting temperature. The magnet assembly, the thermal shield, the magnet support structure, and / or the cryogen container can be thermally connected to the cryocooler via a heat conductor, a convection loop, and / or a heat pipe. A heat conductor can be made of a solid material with high thermal conductivity, in particular a metal such as copper or aluminum.

[0059] In a preferred embodiment, the magnetic resonance device according to the invention is a "dry" scanner comprising a small volume of cryogen. A small volume can be characterized, for example, by a volume of less than 10 l, less than 5 l, or less than 1 l. For example, the magnetic resonance device according to the invention can comprise one or more small cryogen containers which are thermally and mechanically connected to the superconducting magnet via a heat conductor. The one or more small cryogen containers can each comprise a volume of less than 10 l, less than 5 l, or preferably less than 1 l of cryogen. According to one embodiment of the magnetic resonance device according to the invention, cryogen containers are omitted entirely, so that the magnet assembly is cooled completely by heat conduction via a heat conductor.A dry scanner can further be characterized by the fact that the superconducting magnet is not immersed in a cryogenic bath. Preferably, in a dry scanner, the superconducting magnet is connected to the cryogenic cooler by means of a heat conductor according to an embodiment described above.

[0060] The magnetic resonance device shares the advantages of the magnet arrangement according to the invention as described above. Particularly in dry scanners, the provision of a magnet arrangement according to the invention is advantageous because, by eliminating the need for a cryogen bath, which increases the thermal capacity of the cold mass of the magnetic resonance device, a rapid and reliable discharge of electrical energy from the superconducting magnet into the discharge system can be ensured.

[0061] According to one embodiment, the magnetic resonance device according to the invention comprises a control unit configured to output a control signal in order to control a switching state of the switch.

[0062] The control unit can be configured to manage the overall operation of the magnetic resonance device. In particular, the control unit can include a processing unit, a storage unit, and software for controlling various components of the magnetic resonance device. The control unit can also be configured to monitor the state of the superconducting magnet and, if necessary, initiate a magnetic discharge process, that is, a discharge of electrical energy from the superconducting magnet into the discharge system.

[0063] A control unit can enable automated and precise control of the magnetic discharge process. The control unit can advantageously respond to emergency situations, such as a power outage or unexpected heating of the superconducting magnet, and / or prepare for planned maintenance procedures. In particular, the control unit can advantageously improve the safety and reliability of the magnetic resonance device.

[0064] Further advantages and details will become apparent from the following description of exemplary embodiments in conjunction with the drawings. These show, in schematic representation: Fig. 1 shows a schematic view of a magnetic resonance device according to one aspect of the present invention; Fig. 2 a circuit diagram of a magnet arrangement for a magnetic resonance device according to one aspect of the present invention; Fig. 3 a schematic circuit diagram of a magnet arrangement for a magnetic resonance device according to one aspect of the present invention; Fig. 4 a circuit diagram of a magnet arrangement with a cooling unit for a magnetic resonance device according to one aspect of the present invention; and Fig. 5 a circuit diagram of a magnetic arrangement with a battery storage system for a magnetic resonance device according to one aspect of the present invention.

[0065] The present invention relates to magnetic resonance devices and magnet arrangements for the efficient management of the discharge of electrical energy from superconducting magnets. Magnetic resonance devices can include superconducting magnets configured to generate a magnetic field for imaging purposes.

[0066] In one embodiment, the magnetic resonance device according to the invention comprises a magnet arrangement with a discharge system which is designed to absorb electrical energy from the superconducting magnet and / or convert it into heat energy and dissipate it to an environment.

[0067] A magnetic arrangement according to the invention can include a switch which is configured to interrupt a closed circuit in the superconducting magnet and to feed electrical energy into the discharge system.

[0068] The discharge system includes a supercapacitor designed to buffer the transfer of electrical energy from the superconducting magnet to a discharge element within the system. A supercapacitor can be configured to absorb and temporarily store large amounts of electrical energy during a magnetic discharge process.

[0069] In one embodiment, the discharge system can include a resistive element configured to convert the electrical energy released during the discharge processes into thermal energy and dissipate it to the environment. The supercapacitor can be configured to release stored electrical energy to the resistive element in a controlled manner.

[0070] In one embodiment, the discharge system of the magnetic arrangement can include a battery storage system. In such configurations, the supercapacitor can be configured to transfer stored electrical energy to the battery storage system for possible reuse.

[0071] In a further embodiment, the discharge system of the magnetic arrangement can include a conditioning unit. A conditioning unit can be configured to receive electrical energy from the superconducting magnet and / or the supercapacitor and to transfer electrical energy to the battery storage system at a predetermined voltage and / or current. It is conceivable that the conditioning unit is configured to control an energy transfer rate in order to maintain a substantially constant current drop rate during the magnetic discharge process.

[0072] A magnet arrangement according to the invention can include a cooling unit which is designed to actively cool the resistive element or a heat exchanger of the resistive element during a magnetic discharge process.

[0073] In one embodiment, the switch of the magnetic assembly can include a superconducting element which is kept below a superconducting temperature during normal operation in order to maintain the closed circuit in the superconducting magnet. It is conceivable that the magnetic assembly includes a heating device configured to raise the temperature of the superconducting element and thus enable a controlled initiation of a magnetic discharge process.

[0074] In another embodiment, the supercapacitor of the magnet arrangement can comprise a lithium-ion capacitor.

[0075] The superconducting magnet of the magnet arrangement can be configured to provide a magnetic field with a magnetic field strength of 1.5 Tesla, 2 Tesla, 2.5 Tesla or 3 Tesla.

[0076] The magnetic resonance device according to the invention can be configured to perform a magnetic resonance measurement of an object positioned within an imaging area of ​​the magnetic resonance device. The magnetic resonance device can, in particular, include a control unit configured to manage the overall operation of the magnetic resonance device, including the control of switching states in the magnetic arrangement during imaging and magnetic discharge processes.

[0077] Fig. Figure 1 shows an embodiment of a magnetic resonance imaging (MRI) device 10 according to the invention. In the illustrated example, the MRI device 10 comprises a static field magnet or main magnet 12, which is configured to provide a homogeneous, static magnetic field 13 (B0 field). The main magnet 12 comprises one or more superconducting magnets or superconducting magnetic coils. The static magnetic field 13 penetrates an imaging area 14 in which an object 15 is positioned for an imaging examination. The imaging area 14 may coincide with a patient acquisition area, which is configured to acquire the object, in particular a patient, during a magnetic resonance examination. The imaging area 14 is at least partially enclosed by the main magnet 12 along a circumferential direction. The main magnet 12 forms part of the magnetic arrangement 11 according to the invention.

[0078] The magnetic resonance imaging (MRI) device 10 can include a patient positioning device 16, which is configured to transport the patient 15 into the imaging area 14. In particular, the patient positioning device 16 can be configured to transport a diagnostically relevant body region of the patient 15 into an imaging volume or an isocenter (not shown) of the MRI device 10.

[0079] In one embodiment, the magnetic resonance device 10 comprises a gradient system with one or more gradient coils 18. The gradient coils 18 can be configured to generate magnetic field gradients in different spatial directions, preferably orthogonally oriented to one another. The magnetic field gradients can be used for the spatial encoding of magnetic resonance signals acquired during a magnetic resonance examination. The gradient coils 18 can be activated or controlled by a corresponding control signal provided by a gradient control unit 19 or a gradient amplifier. For this purpose, the gradient coils 18 can be electrically connected to the gradient control unit 19 via an electrical signal connection 27.

[0080] The magnetic resonance imaging (MRI) device 10 may further include an integrated high-frequency antenna 20 (also referred to as a body coil). The high-frequency antenna 20 may be activated or controlled by means of a high-frequency control unit 21 or a high-frequency amplifier. The high-frequency control unit 21 may be configured to control the high-frequency antenna 20, generate a high-frequency magnetic field (B1 field), and deliver high-frequency excitation pulses into the imaging area 14.

[0081] In one embodiment, the magnetic resonance device 10 comprises a local coil 26. The local coil 26 can be positioned on or near the diagnostically relevant region of the patient 15 (e.g., on the head region, as in Fig. (1 shown). The local coil 26 can be configured to emit high-frequency excitation pulses into the patient 15 and / or to receive magnetic resonance signals from the patient 15. It is conceivable that the local coil 26 is controlled by means of the high-frequency control unit 21. The high-frequency antenna 20 and / or the local coil 26 can be electrically connected to the high-frequency control unit 21 by means of an electrical signal connection 27.

[0082] The magnetic resonance device 10 further comprises a control unit 22, which is designed to control the magnetic resonance device 10. In the Fig. In the example shown, the control unit 22 comprises a processing unit 28, which is configured to process magnetic resonance signals and reconstruct magnetic resonance images. The processing unit 28 can further be configured to process input from a user of the magnetic resonance device 10 and / or provide output to the user. For this purpose, the processing unit 28 and / or the control unit 22 can be connected to a display unit 24 and an input unit 25 via a suitable signal connection. For the preparation of a magnetic resonance examination, preparatory information, such as imaging parameters, as well as patient information, can be provided to the user by means of the display unit 24. The display unit 24 can, for example, comprise one or more screens or monitors. The display unit 24 can be configured to provide the user with control information, such as...The display unit 24 can further be configured to provide a graphical user interface with a representation of a diagnostically relevant body region of the patient 15. The input unit 25 can be configured to receive information and / or imaging parameters from the user.

[0083] In one embodiment, the display unit 24 and the input unit 25 can form part of a user interface 23. The user interface 23 can be connected to the control unit 22 via a suitable signal connection.

[0084] The magnetic resonance device 10 according to the invention comprises a magnet arrangement 11 according to the invention, which in connection with the Fig. 2 to 5 are described in more detail.

[0085] Naturally, the magnetic resonance imaging (MRI) device may include 10 additional components and / or functions that are common in MRI devices. The general operating principle of an MRI device 10 is known to those skilled in the field, so a more detailed description is omitted.

[0086] With reference to Fig. 2. A magnetic arrangement 11 for a magnetic resonance device 10 can comprise a superconducting magnet 12 connected to a discharge system 35. The magnetic arrangement 11 can include a switch 37 configured to interrupt a closed circuit in the superconducting magnet 12 and divert electrical energy accumulated in the superconducting magnet 12 to the discharge system 35. The switch 37 can be electrically arranged between the superconducting magnet 12 and the discharge system 35.

[0087] The discharge system 35 can include a supercapacitor 30 which is configured to buffer a transfer of electrical energy from the superconducting magnet 12 to a discharge element in the discharge system 35.

[0088] In some embodiments, the discharge system 35 may include a conditioning unit 31 and a battery storage system 33 (see Fig. 2 and Fig. 5) The supercapacitor 30 can be connected in parallel to the conditioning unit 31 and to the battery storage system 33.

[0089] Preferably, the conditioning unit 31 and the battery storage system 33 are connected in series. The supercapacitor 30 can be configured to receive and buffer the electrical energy from the superconducting magnet 12 when the switch 37 is activated or opened. The electrical energy accumulated in the superconducting magnet 12 can be transferred to the battery storage system 33 as soon as the switch 37 is opened.

[0090] The conditioning unit 31 can include a converter, in particular a DC / DC converter. The conditioning unit 31 can be configured to adjust the voltage and / or current of an electric current supplied by the superconducting magnet 12 and / or the supercapacitor 30 to meet the requirements of the battery storage system 33.

[0091] In the Fig. In the example shown, the discharge element in the discharge system 35 comprises a battery storage system 33. The supercapacitor 30 can be configured to receive and store electrical energy from the superconducting magnet 12 and to release the electrical energy to the battery storage system 33. Such a configuration of the discharge system 35 can enable efficient energy transfer and storage during the discharge process of the superconducting magnet 12.

[0092] The discharge system 35 can further comprise a conditioning unit 31. The conditioning unit 31 can be configured as part of the discharge element. Preferably, the conditioning unit 31 is configured to receive electrical energy from the superconducting magnet 12 and / or the supercapacitor 30. In one embodiment, the conditioning unit 31 provides electrical energy to the battery storage system 33 at a predetermined voltage. Such voltage conditioning can ensure that the electrical energy from the superconducting magnet 12 and / or the supercapacitor 30 meets the requirements of the battery storage system 33.

[0093] It is conceivable that the conditioning unit 31 is configured to adapt the properties of the electrical energy as it is fed into the battery storage system 33 by the superconducting magnet 12 and / or the supercapacitor 30. In one embodiment, the conditioning unit 31 is configured to maintain a constant voltage at an input while adjusting the phase relationship between voltage and current at an output. This control mechanism enables efficient energy transfer and also protects the battery storage system 33 from potential voltage or current fluctuations.

[0094] The battery storage system 33 can comprise one or more rechargeable batteries configured to store the electrical energy discharged from the superconducting magnet 12. In one embodiment, the battery storage system 33 includes a battery management system that monitors and controls the charging process. This ensures improved or optimized energy storage and battery life.

[0095] With reference to Fig. 3. A magnetic arrangement 11 for a magnetic resonance device 10 can comprise a superconducting magnet 12, which is connected to a discharge system 35. The magnetic arrangement 11 includes a switch 37, which is configured to interrupt a closed circuit in the superconducting magnet 12 and to transfer electrical energy from the superconducting magnet 12 to the discharge system 35.

[0096] Within the discharge system 35, a supercapacitor 30 and a resistive element 34 are connected in parallel. The resistive element 34 can be configured to convert the electrical energy received from the superconducting magnet 12 into thermal energy and to dissipate the thermal energy to the environment. In particular, the resistive element 34 can comprise a heat sink or heat exchanger configured to transfer the thermal energy to a cooling medium.

[0097] The switch 37 can be activated to interrupt the closed circuit in the superconducting magnet 12 and divert the accumulated electrical energy to the discharge system 35. In a preferred embodiment, the resistive element 34 provides a means for dissipating excess electrical energy as heat energy.

[0098] The supercapacitor 30 can be configured to buffer the transfer of electrical energy from the superconducting magnet 12 to the resistive element 34. Such a configuration of the magnet arrangement 11 allows for a reduction in the size and / or mass of the resistive element 34 and / or the heat sink compared to a discharge system 35 without a supercapacitor 30. In some cases, the peak temperature of the resistive element 34 and / or the heat sink during shutdown of the superconducting magnet can be reduced compared to a discharge system without a supercapacitor 30.

[0099] The discharge system 35 enables a controlled discharge of the superconducting magnet 12, with the supercapacitor 30 serving as an intermediate energy storage element and the resistive element 34 providing a pathway for dissipating the electrical energy in the form of heat energy. In some embodiments, the supercapacitor 30 receives and stores electrical energy from the superconducting magnet 12 and transfers the electrical energy in a controlled manner to the resistive element 34.

[0100] With reference to Fig. A magnetic arrangement 11 for a magnetic resonance device 10 can comprise a superconducting magnet 12, a discharge system 35, and a switch 37. The switch 37 can be configured to electrically connect and disconnect the superconducting magnet 12 from the discharge system 35 depending on the switching state of the switch 37. It is conceivable that the switching state of the switch 37 is controlled by the control unit 22. The control unit 22 can therefore be configured to transmit a control command for controlling the switching state of the switch 37 to the switch and / or the superconducting element (not shown) of the switch 37.

[0101] Within the discharge system 35, a supercapacitor 30 can be connected in parallel to a resistive element 34. The resistive element 34 can be thermally coupled to a cooling unit 36. The cooling unit 36 ​​can be configured to cool the resistive element 34.

[0102] In one embodiment, the cooling unit 36 ​​comprises a fan configured to blow air or a gaseous cooling medium over a surface of the heat sink of the resistance element 34. In another embodiment, the cooling unit 36 ​​comprises a heat exchanger that is thermally and mechanically connected to the resistance element 34. The cooling unit 36 ​​can be configured to transport a liquid cooling medium through the heat exchanger.

[0103] The components of the magnet assembly 11, such as the superconducting magnet 12, the switch 37, one or more supercapacitors 30, and the resistive element 34, can be connected to each other to form a circuit that enables a controlled discharge of electrical energy from the superconducting magnet 12 via the supercapacitor 30 and the resistive element 34. The cooling unit 36 ​​provides active cooling of the resistive element 34 while the electrical energy is converted into thermal energy.

[0104] In one embodiment, the size and / or mass of the resistive element 34 and / or the heat sink can be reduced compared to conventional magnet arrangements without a supercapacitor 30. Furthermore, the peak temperature of the resistive element 34 and / or the heat sink during shutdown of the superconducting magnet 12 can be reduced compared to conventional magnet arrangements.

[0105] The cooling unit 36 ​​can be configured to actively cool the resistive element 34 during the discharge process, thus enabling more efficient heat dissipation. This allows the use of a smaller resistive element 34 or a smaller heat sink, while still effectively dissipating the thermal energy generated during the discharge of the superconducting magnet 12.

[0106] With reference to Fig.5. A magnetic arrangement 11 for a magnetic resonance device can comprise a superconducting magnet 12, which is connected to a discharge system 35. The magnetic arrangement 11 includes a switch 37, which is configured to electrically connect and disconnect the superconducting magnet 12 from the discharge system 35 depending on the switching state of the switch 37. A control unit 22 can be configured, according to an embodiment described above, to control the switching state of the switch 37.

[0107] Within the discharge system 35, a supercapacitor 30 and a resistive element 34 are connected in parallel to a battery storage system 33. The battery storage system 33 is connected in series with a conditioning unit 31. The conditioning unit 31 can be configured to condition electrical energy supplied by the superconducting magnet 12 and / or the supercapacitor 30 according to the requirements of the battery storage system 33. For example, the conditioning unit 31 can be configured to adjust the voltage and / or current of the electrical energy supplied to the battery storage system 33.

[0108] The supercapacitor 30 can be configured to buffer the transfer of electrical energy from the superconducting magnet 12 to the resistive element 34 and / or the battery storage system 33. The resistive element 34 can be configured to dissipate the received electrical energy as heat when the battery storage system 33 and / or the conditioning unit 31 are inactive, unavailable, or in a fault mode.

[0109] In one embodiment, the resistive element 34 comprises a switch configured to electrically disconnect the resistive element 34 from the discharge system 35 when electrical energy is fed from the superconducting magnet 12 into the battery storage system 33. In another embodiment, a first portion of the electrical energy from the superconducting magnet 12 can be converted into heat energy by means of the resistive element 34, while a second portion of the electrical energy from the superconducting magnet 12 is fed into the battery storage system 33.

[0110] The conditioning unit 31 and / or the battery storage system 33 may include a switch configured to electrically disconnect the conditioning unit 31 and / or the battery storage system 33 from the discharge system 35 in cases where a discharge of the electrical energy accumulated in the superconducting magnet 12 via the resistance element 34 is preferred or where the battery storage system 33 and / or the conditioning unit 31 are inactive or unavailable.

[0111] The conditioning unit 31 can be configured to receive electrical energy from the superconducting magnet 12 and / or the supercapacitor 30 and to supply electrical energy to the battery storage system 33 at a predetermined voltage. In one embodiment, the conditioning unit 31 is configured to supply the battery storage system 33 with electrical energy at a substantially constant current decay rate.

[0112] The battery storage system 33 can include a battery management system configured to manage and / or control functions of the battery storage system 33. The battery management system can determine a state of charge and / or a health status of the battery storage system 33. In one embodiment, the battery management system is configured to communicate with the conditioning unit 31 to set or adjust a property of the electrical energy fed into the battery storage system 33.

[0113] In one embodiment, the conditioning unit 31 can be included in the battery storage system 33.

[0114] In one embodiment, the supercapacitor 30 comprises a lithium-ion capacitor. Lithium-ion capacitors can combine features of both lithium-ion batteries and electrical double-layer capacitors, thus providing high energy density and power density. The use of lithium-ion capacitors in the discharge system 35 can enable efficient energy storage and high discharge rates of the superconducting magnet 12.

[0115] The switch 37 can include a superconducting element configured to maintain the closed circuit of the superconducting magnet 12 when cooled below a superconducting temperature. When the temperature of the superconducting element exceeds the superconducting temperature, the switch 37 can break the closed circuit and thus initiate the discharge process.

[0116] In one embodiment, the superconducting magnet 12 is configured to generate a magnetic field with a magnetic field strength of at least 1.5 Tesla. It is also conceivable that the superconducting magnet 12 is configured to generate a magnetic field with a magnetic field strength of at least 2 Tesla, at least 2.5 Tesla, or at least 3 Tesla. The magnetic field strength can depend on the requirements of the magnetic resonance device 10 and the intended imaging applications.

[0117] The supercapacitor 30 can be implemented as an array of multiple supercapacitors (supercapacitor array). The array of multiple supercapacitors can be configured in various ways. For example, multiple supercapacitors can be connected in series to increase the overall voltage rating of the supercapacitor array. In another example, multiple supercapacitors are connected in parallel to increase the overall capacitance and energy storage capacity of the supercapacitor array. Some configurations may use a combination of series and parallel connections to optimize both voltage handling and energy storage characteristics.

[0118] The superconducting element of the switch 37 can comprise a low-temperature superconductor, such as a niobium-titanium alloy, or a high-temperature superconductor. Preferably, the magnetic resonance device 10 includes a cryogenic cooler configured to maintain the superconducting element below a critical temperature, or superconducting temperature, during normal operation of the magnetic resonance device. In some aspects, the switch 37 includes a heating element configured to be activated to raise the temperature of the superconducting element above the critical temperature, thereby opening the switch and initiating the discharge process of the superconducting magnet.

[0119] The magnet assembly can include a heating device configured to heat the superconducting element of the switch in response to a control signal. This heating device enables precise control of the switching process by raising the temperature of the superconducting element above the critical temperature, thereby breaking the closed circuit in the superconducting magnet.

[0120] The resistive element and / or its heat sink can be designed with various geometries to optimize heat dissipation. In some aspects, the resistive element and / or heat sink feature a finned structure with varying fin densities, shapes, and / or orientations. Providing a finned structure can increase the surface area available for heat transfer and thus improve the overall cooling efficiency of the heat sink.

[0121] The heat sink can incorporate or be made of various materials with high thermal conductivity. Copper, aluminum, and their alloys, as well as materials like graphene-reinforced composites, can be used to improve heat dissipation efficiency. The choice of material depends on factors such as thermal conductivity, weight considerations, and cost-effectiveness for the specific application.

[0122] The cooling unit can also include a liquid cooling system, which is designed to transport a coolant such as water, ethylene glycol, or dielectric fluids through a heat exchanger of the resistance element. A liquid cooling system can improve the removal of heat energy from the resistance element compared to air cooling.

[0123] The conditioning unit can be designed with various power electronic topologies to optimize energy transfer and energy management within the magnet assembly. In one embodiment, the conditioning unit includes a bidirectional DC-DC converter with appropriate control algorithms. This configuration enables efficient energy flow in both directions, thus allowing effective energy recovery during the shutdown and startup processes of the superconducting magnet.

[0124] The bidirectional DC-DC converter can include customized control algorithms designed to dynamically manage voltage and current levels. These control algorithms can adapt to changing conditions in the superconducting magnet, supercapacitor, and / or battery storage system, thus ensuring improved or optimized energy transfer between components of the magnet assembly. EXAMPLES Example 1: Configuration of the magnet arrangement

[0125] A magnetic array for a magnetic resonance device comprises a superconducting magnet 12, which is configured to generate a main magnetic field with a magnetic field strength of 3 Tesla. The magnetic array further comprises a switch 37 and a discharge system 35 with a supercapacitor 30, a conditioning unit 31, a battery storage system 33, a heat sink 34, and a cooling unit 36. The switch 37 is configured to interrupt the closed circuit in the superconducting magnet 12 and divert electrical energy to the discharge system 35.

[0126] The supercapacitor 30 is a 100 F lithium-ion capacitor with a nominal voltage between 2 and 20 V, connected in parallel to the resistor 34. The conditioning unit 31 is a bidirectional DC-DC converter capable of handling peak powers of up to 2 kW, 5 kW, 7 kW, 15 kW, or 20 kW. The battery storage system 33 consists, for example, of a 48 V, 200 Ah lithium-ion battery pack. However, it is also conceivable that battery packs with a nominal voltage of 12 V, 3.6 V, or multiples of 3.6 V could be used. The resistor 34 has a copper heat sink with a finned structure, which, for example, has a surface area of ​​2 m². 2 offers. The cooling unit 36 ​​has a fan which blows air over the rib structure of the resistance element 34.

[0127] During a controlled shutdown, the switch 37 opens, and the supercapacitor 30 initially absorbs the high-power discharge from the superconducting magnet 12. The conditioning unit 31 then transfers energy from the supercapacitor 30 to the battery storage system 33 at a controlled rate of up to 10 kW. Excess energy is dissipated by the resistance element 34, with the cooling unit 36 ​​maintaining the temperature of the heat sink below 60°C. Example 2: Energy distribution during the magnetic discharge process

[0128] In this example, the magnet arrangement includes a superconducting magnet 12, which is configured to provide a main magnet with a magnetic field strength of 3 Tesla. The superconducting magnet 12 stores approximately 15 MJ of energy. At the start of the discharge process, the energy is distributed as follows: 1. The supercapacitor 30 initially absorbs 2 MJ of energy within the first 0.5 seconds of the discharge process. 2. In the next 5 minutes, the conditioning unit 31 transfers an energy of 10 MJ from the supercapacitor 30 and the superconducting magnet 12 to the battery storage system 33. 3. A further 3 MJ of energy is dissipated as heat to the environment through the resistance element 34 over a period of approximately 10 minutes.

[0129] The conditioning unit 31 maintains a constant current drop rate of 100 A / min during energy transfer to the battery storage system 33. The cooling unit 36 ​​operates continuously and keeps the temperature of the heat sink 34 below 55°C throughout the entire discharge process. Example 3: Energy recovery during the startup of the superconducting magnet

[0130] After maintenance, the magnet assembly 11 uses the energy stored in the battery storage system 33 for a startup process. The battery storage system 33 contains approximately 8 MJ of energy from a previous magnet discharge. In this example, the conditioning unit 31 operates in reverse, transferring electrical energy from the battery storage system 33 to the superconducting magnet 12 with a power output of up to 10 kW or up to 15 kW. In this process, for example, approximately 7 MJ of energy can be recovered. This reduces the electrical energy required from an external power source to fully energize the superconducting magnet 12.

[0131] These examples demonstrate the efficient energy management capabilities of the magnet arrangement and show the interaction between the supercapacitor, conditioning unit, battery storage system and heat sink during both the discharge and charging processes.

Claims

[1] A magnet arrangement (11) for a magnetic resonance apparatus (10), comprising: a superconducting magnet (12); a discharge system (35); a switch (37) configured to interrupt a closed circuit in the superconducting magnet (12) and to transfer electrical energy accumulated in the superconducting magnet (12) to the discharge system (35); wherein the discharge system (35) comprises a supercapacitor (30) configured to buffer a transfer of electrical energy from the superconducting magnet (12) to a discharge element in the discharge system (35). [2] The magnet assembly (11) of claim 1, wherein the discharge element comprises a resistance element (34), and wherein the supercapacitor (30) is configured to receive electrical energy from the superconducting magnet (12), store it, and transfer the electrical energy to the resistance element (34). [3] The magnet assembly (11) according to claim 1 or 2, wherein the discharge element comprises a battery storage system (33), and wherein the supercapacitor (30) is configured to receive electrical energy from the superconducting magnet (12), store it, and deliver the electrical energy to the battery storage system (33). [4] The magnet assembly (11) according to claim 3, wherein the discharge element comprises a conditioning unit (31) configured to receive electrical energy from the superconducting magnet (12) and / or the supercapacitor (30) and to provide electrical energy at a predetermined voltage to the battery storage system (33). [5] The magnet assembly (11) of claim 1, wherein the unloading system (35) comprises: a resistance element (34); and a battery storage system (33), wherein the supercapacitor (30) is configured to receive electrical energy from the superconducting magnet (12), to store it, and to deliver the electrical energy to the resistance element (34) and / or the battery storage system (33). [6] The magnet assembly (11) according to claim 5, further comprising a conditioning unit (31) configured to receive electrical energy from the superconducting magnet (12) and / or the supercapacitor (30) and to provide electrical energy at a predetermined voltage to the battery storage system (33). [7] The magnet assembly (11) according to claim 4 or claim 6, wherein the conditioning unit (31) is configured to provide the electrical energy to the battery storage system (33) at a substantially constant current decay rate. [8] The magnet arrangement (11) according to any one of the preceding claims, wherein the discharge element comprises a resistance element (34), and wherein the supercapacitor (30) is configured to receive electrical energy from the superconducting magnet (12), to store it and to deliver the electrical energy to the resistance element (34), further comprising a cooling unit (36) configured to cool the resistance element (34). [9] The magnet assembly (11) according to any one of the preceding claims, wherein the switch (37) comprises a superconducting element adapted to maintain the closed circuit in the superconducting magnet (12) when cooled below a superconducting temperature. [10] The magnet assembly (11) of claim 9, further comprising a heating device configured to heat the superconducting element of the switch (37) in response to a control signal. [11] The magnet assembly (11) according to any one of the preceding claims, wherein the supercapacitor (30) comprises or consists of a lithium-ion capacitor. [12] The magnet arrangement (11) according to any one of the preceding claims, wherein the superconducting magnet (12) is designed to generate a magnetic field strength of at least 1.5 Tesla, at least 2 Tesla, at least 2.5 Tesla or at least 3 Tesla. [13] A magnetic resonance device (10) which is designed to carry out a magnetic resonance measurement of an object (15) which is positioned within an imaging region (14) of the magnetic resonance device (10), comprising a magnet arrangement (11) according to one of claims 1 to 12. [14] The magnetic resonance apparatus (10) according to claim 13, further comprising a control unit (22) which is configured to output a control signal in order to control a switching state of the switch (37).

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