Operation terminal, operation terminal actuation method, and magnetic resonance imaging system

Abstract

To provide an operation terminal that allows a user to understand the state of a magnet correctly, and an operation terminal actuation method, and to provide a magnetic resonance imaging system equipped with the operation terminal.SOLUTION: An operation terminal of the present invention is an operation terminal of a magnetic resonance imaging device, and includes: a processor; and a non-temporary and tangible recording medium for recording a parameter value on a magnet equipped to the magnetic resonance imaging device and the state of the magnet corresponding to the parameter value by associating them with each other. The processor acquires a parameter value from the magnetic resonance imaging device, refers to the recording medium on the basis of the acquired value, determines which of a plurality of states that the magnet can take an actual state of the magnet is, and notifies the determined actual state of the magnet.SELECTED DRAWING: Figure 18

Description

Technical Field

[0001] The present invention relates to an operation terminal of a magnetic resonance imaging apparatus, a method of operating the operation terminal, and a magnetic resonance imaging system, and particularly relates to a technique for notifying the state of a magnet provided in the magnetic resonance imaging apparatus.

Background Art

[0002] In a magnetic resonance imaging apparatus (MRI apparatus, MRI: Magnetic Resonance Imaging), cooling of a superconducting magnet using liquid helium has been performed until now. In such an MRI apparatus, since highly specialized knowledge and techniques are required for the control and adjustment of the cooling of the superconducting magnet, specialized service personnel have been performing the work.

[0003] On the other hand, in recent years, techniques for reducing the amount of liquid helium used and techniques for cooling a magnet without using liquid helium have been developed, and it is expected that such techniques will continue to progress in the future. For example, Patent Document 1 describes an MRI apparatus in which a cooling container is helium-free.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of the progress of the above-described techniques for reducing the amount of liquid helium used and techniques for cooling a magnet without using liquid helium, it is preferable that not only specialized service personnel with highly specialized knowledge and techniques but also general users such as technicians who use an MRI apparatus in ordinary examinations and the like can correctly understand the state of the magnet and perform appropriate operations. However, the conventional techniques as shown in Patent Document 1 are not such that general users can correctly understand the state of the magnet.

[0006] The present invention has been made in view of such circumstances, and an object thereof is to provide an operation terminal that allows a user to correctly understand the state of a magnet, a method of operating the operation terminal, and a magnetic resonance imaging system including such an operation terminal.

Means for Solving the Problems

[0007] In order to achieve the above-described object, an operation terminal according to a first aspect of the present invention is an operation terminal of a magnetic resonance imaging apparatus, and includes a processor, and a non-temporary and tangible recording medium that records, in association with each other, a value of a parameter related to a magnet included in the magnetic resonance imaging apparatus and a state of the magnet corresponding to the value of the parameter. The processor acquires the value of the parameter from the magnetic resonance imaging apparatus, refers to the recording medium based on the acquired value, determines which of a plurality of states that the magnet can take is the actual state of the magnet, and notifies the determined actual state of the magnet.

[0008] According to the first aspect, since the processor determines which of a plurality of states that the magnet can take is the actual state of the magnet and notifies the determined actual state of the magnet, the user can correctly understand the state of the magnet.

[0009] In the operation terminal according to a second aspect, in the first aspect, the parameter includes at least one of the temperature of the magnet, the current applied to the magnet, and the voltage between the lead terminals of the magnet.

[0010] In the operation terminal according to a third aspect, in the first or second aspect, the plurality of states that the magnet can take are a demagnetized state, a cooling state, a cooled state, an exciting state, and an excited state.

[0011] In the operation terminal according to a fourth aspect, in any one of the first to third aspects, the magnet is a superconducting magnet for generating a static magnetic field included in the magnetic resonance imaging apparatus.

[0012] In the operation terminal according to the fifth aspect, in any one of the first to fourth aspects, the processor performs notification by at least one of a display device and an audio output device.

[0013] In the operation terminal according to the sixth aspect, in any one of the first to fifth aspects, the processor acquires the value of a parameter at determined time intervals, makes a determination, and performs notification when the actual state of the magnet changes.

[0014] In the operation terminal according to the seventh aspect, in any one of the first to sixth aspects, the processor accepts an operation according to the actual state of the magnet, and transmits an instruction corresponding to the accepted operation to the magnetic resonance imaging apparatus.

[0015] In the operation terminal according to the eighth aspect, in the seventh aspect, the processor prompts the user of the operation terminal to execute an action according to the actual state of the magnet for at least some of the plurality of states that the magnet can take, and accepts the operation when the action is executed.

[0016] In the operation terminal according to the ninth aspect, in the eighth aspect, the processor prompts the user to perform a safety check as an action when the actual state of the magnet is the cooled state, and instructs the magnetic resonance imaging apparatus to start exciting the magnet when the safety check is executed.

[0017] In the operation terminal according to the tenth aspect, in the ninth aspect, the processor prompts the user to perform a first safety check that there is no magnetic substance near the magnetic resonance imaging apparatus and that there is no human near the magnetic resonance imaging apparatus, and a second safety check for starting excitation, as safety checks. In the tenth aspect, it is preferable that the processor prompts the user to perform the second safety check after the first safety check is executed.

[0018] In the operation terminal according to the 11th aspect, in any one of the 8th to 10th aspects, the recording medium records by associating the actual state of the magnet with the information indicating the action, and the processor determines the action by referring to the recording medium according to the determined actual state of the magnet.

[0019] To achieve the above object, an operation method of an operation terminal according to the 12th aspect of the present invention is an operation method of an operation terminal of a magnetic resonance imaging apparatus. The operation terminal includes a processor and a non-transitory and tangible recording medium that records by associating the value of a parameter related to a magnet included in the magnetic resonance imaging apparatus with the states that the magnet can take. The processor acquires the value of the parameter from the magnetic resonance imaging apparatus, refers to the recording medium based on the acquired value, determines which of the plurality of states that the magnet can take the actual state of the magnet is, and notifies the determined actual state of the magnet. According to the 12th aspect, similar to the 1st aspect, the user can correctly understand the state of the magnet.

[0020] To achieve the above object, a magnetic resonance imaging system according to the 13th aspect of the present invention includes an operation terminal according to any one of the 1st to 11th aspects and a magnetic resonance imaging apparatus. According to the 13th aspect, similar to the 1st and 12th aspects, the user can correctly understand the state of the magnet.

Effect of the Invention

[0021] As described above, according to the operation terminal, the operation method of the operation terminal, and the magnetic resonance imaging system of the present invention, the user can correctly understand the state of the magnet.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of an operation terminal, an operation method of the operation terminal, and a magnetic resonance imaging system according to the present invention will be described. Note that in the accompanying drawings, for convenience of explanation, illustration of some components may be omitted.

[0024] [First Embodiment] [Configuration of Magnetic Resonance Imaging System] FIG. 1 is a diagram showing the overall configuration of a magnetic resonance imaging system 10 (magnetic resonance imaging system; MRI system) according to the first embodiment. In the figure, the magnetic resonance imaging system 10 includes a magnetic resonance imaging apparatus 100 (magnetic resonance imaging apparatus, MRI apparatus), an operation terminal 200 (operation terminal, first terminal device; on-site operation terminal) installed close to the magnetic resonance imaging apparatus 100, and an operation terminal 300 (operation terminal, second terminal device; service site operation terminal) installed away from the magnetic resonance imaging apparatus 100. The magnetic resonance imaging apparatus 100, the operation terminal 200, and the operation terminal 300 can communicate with each other via a network (not shown).

[0025] Note that the operation terminal 200 can be installed, for example, in the examination room where the magnetic resonance imaging apparatus 100 is installed, or in a location adjacent to the examination room where the inside of the examination room can be visually recognized. Hereinafter, the examination room and the location where the inside of the examination room can be visually recognized may be collectively referred to as the "site". On the other hand, the operation terminal 300 is installed at a service site, such as another floor of the same building as the examination room, a building different from the examination room, or a site different from the examination site. The operation terminal 300 (operation terminal for service site) may be communicable with a plurality of magnetic resonance imaging apparatuses 100 and operation terminals 200 (operation terminals for site). Also, one magnetic resonance imaging apparatus 100 and operation terminal 200 may be communicable with a plurality of operation terminals 300. Note that the operation terminal 200 is connected to (communicable with) a control unit 103 described later, but exists as a separate body from the control unit 103. Also, the operation terminal 300 is also connected to the control unit 103, but exists as a separate body from the control unit 103.

[0026] The magnetic resonance imaging apparatus 100 includes a magnet 110 which is a superconducting magnet for generating a static magnetic field. The magnet 110 includes a vacuum vessel configured to block external heat, and a heat shield and a cooling vessel are provided in this vacuum vessel, and the inside of the cooling vessel is maintained in a vacuum. That is, the cooling vessel has a configuration without liquid helium. And a superconducting coil is provided in this cooling vessel. The superconducting coil is wound around a bobbin (support member). The refrigerator 101 cools the superconducting coil wound around the bobbin by expanding the refrigerant gas compressed by the compressor 102 to generate cold heat and directly cooling the bobbin. The magnetic resonance imaging apparatus 100 may include a plurality of refrigerators 101.

[0027] The magnet 110 is provided with a pressure measurement unit 104 and a shield temperature measurement unit 106, all of which are controlled by the control unit 103. The temperature of the magnet 110 is measured by a magnet temperature measurement unit 107 (thermometer, temperature sensor). Also, an ammeter 108 and a voltmeter 109 are connected to the magnet 110, and these devices measure the current and voltage (the voltage between the lead terminals of the magnet 110) applied to the coil of the magnet 110. The data (including temperature, current, and voltage data) received from each of the above measurement units is transmitted by the control unit 103 to the processor 212 (arithmetic unit 212A) and used for determining the actual state of the magnet 110. Note that the magnetic resonance imaging apparatus 100 includes, in addition to the magnet 110 (superconducting coil), a gradient magnetic field generating coil and a high-frequency coil (also referred to as an RF (radio frequency) coil) (both not shown).

[0028] Also, the control unit 103 controls the energization from a power source (not shown) according to an instruction from the processor 212 to excite the magnet 110. The magnet 110 can assume any one of a plurality of states (demagnetized state, cooling state, cooled state, exciting state, and excited state) depending on the cooling and exciting conditions.

[0029] Note that the magnetic resonance imaging apparatus 100 includes an image generation unit (not shown) that generates a magnetic resonance image of a subject. This image generation unit may be provided in the operation terminal 200 (for example, it may be a function of the processor 212), or may be provided separately from the operation terminal 200. Also, the magnetic resonance imaging apparatus 100 includes a bed device 120 on which the subject is placed. The bed device 120 may be detachable from the main body of the magnetic resonance imaging apparatus 100.

[0030] [Configuration of Local Operation Terminal] FIG. 2 is a diagram showing a configuration example of the operation terminal 200 (on-site operation terminal). As shown in the figure, the operation terminal 200 includes a display 202 (display device), a microphone 204 (voice input device), a speaker 206 (voice output device), a keyboard 208 (input device), and a mouse 210 (input device). The user can input instructions to the operation terminal 200 using these devices, and the operation terminal 200 can output the acquired information and notify the state of the magnet using these devices. The display 202 may be configured as a touch panel type display and used as an input device. The operation terminal 200 can be realized as a computer including the elements illustrated in FIG. 2.

[0031] Further, the operation terminal 200 may be provided with a rotating light or a warning light (sometimes referred to as "Rotary Beacon Light" in English) called a patrlight (registered trademark) or a patlamp, and this rotating light or warning light may be used to notify the state of the magnet, give a warning, output the urgency of refrigerator replacement, etc. A plurality of such rotating lights or warning lights having different colors may be provided corresponding to different states of the magnet, the importance of the warning, the urgency of refrigerator replacement, etc. For example, the demagnetized state, the cooling state, and the excited state may be notified or output corresponding to different colors (for example, green or blue, yellow, red, etc.). The same applies to the operation terminal 300.

[0032] The operation terminal 200 also includes a processor 212 (processor), a ROM 214 (ROM: Read Only Memory), and a RAM 216 (RAM: Random Access Memory). The above-described arithmetic unit 212A and remote transmission / reception unit 212B are components of the processor 212, and the processor 212 may include components or functions other than the arithmetic unit 212A and the remote transmission / reception unit 212B. For example, the processor 212 may have a function of generating an image from measurement data. As will be described in detail later, the processor 212 performs processes such as determination of the magnet state, prediction (calculation) of the remaining cooling time and output thereof, safety confirmation and start of excitation when exciting the magnet 110. Note that these processes may be performed by the analysis unit 312B of the operation terminal 300. The processor 212 transmits the collected data (parameters of the magnet 110) and its processing results (state of the magnet 110, etc.) to the operation terminal 300 via the input / output interface 218 and a network (not shown) as necessary.

[0033] In addition, the arithmetic unit 212A (processor 212) calculates each received data, outputs an ON / OFF command for the compressor 102 to the control unit 103 based on the calculation result, and controls the pressure within a certain range so as to bring the output of the heater closer to 0. The arithmetic unit 212A uses the display 202 of each local operation terminal 200 to display each acquired data and the urgency of the chiller replacement. Also, the arithmetic unit 212A uses the remote transmission / reception unit 212B (processor 212) to transmit each acquired data and the urgency of the chiller replacement to the remote transmission / reception unit 312A (processor 312) of the operation terminal 300 (operation terminal for service site) via a communication path such as wireless communication or a data transmission line. The remote transmission / reception unit 312A receives data via the input / output interface 318 and transmits the received data to the analysis unit 312B (processor 312). Similarly, the analysis unit 312B analyzes the data received from other local facilities (magnetic resonance imaging apparatus 100 and operation terminal 200) and analyzes the optimal timing for chiller replacement. The processor 312 may perform processes such as determination of the magnet state, prediction (calculation) of the remaining cooling time and output thereof, safety confirmation at the time of exciting the magnet 110, and start of excitation. Also, the analysis unit 312B can display the received data, analysis data, messages to the user, etc. on the display 302 of the operation terminal 300 or output them via the speaker 306.

[0034] Each part of the operation terminal 200 described above is connected via the bus 222.

[0035] [Examples of information recorded in the recording device] The recording device 220 (non - transitory and tangible recording medium) includes a non - transitory and tangible recording medium such as a magnetic disk, an optical disk, or a semiconductor memory and its control unit, and records various types of information. FIG. 3 is a diagram showing an example of information recorded in the recording device 220. In the example shown in the figure, a magnetic resonance image 220A, cooling curve data 220B, user information 220C, magnet information 220D, and specific operation information 220E are recorded in the recording device 220. Other information may be recorded in the recording device 220.

[0036] The magnetic resonance image 220A is an image obtained by imaging a subject with the magnetic resonance imaging apparatus 100. The cooling curve data 220B is data of a cooling curve showing the relationship between the time since the start of cooling of the magnet 110 (a superconducting magnet for generating a static magnetic field) and the temperature of the magnet 110, which is generated based on measured values and is used for predicting (calculating) the remaining cooling time (see FIG. 12 and the like described later). The user information 220C is information in which the identification information of the user of the operation terminal 200 and information indicating the job types of the user divided into a plurality of levels are associated (see FIG. 8 and the like described later). The magnet information 220D is information in which values of parameters (temperature, current, voltage, etc.) related to the magnet 110 and the states that the magnet 110 can take are associated (see FIG. 10 and the like described later). The specific operation information 220E (specific operation information) is information in which the level (job type) of the user and the operations executable by the users of each level are associated (see FIG. 18 and the like described later). Details of the processing using these pieces of information will be described later.

[0037] [Configuration of the Operation Terminal for the Service Site] FIG. 4 is a diagram showing the configuration of the operation terminal 300 (operation terminal for the service site). Similar to the above-described operation terminal 200 (local operation terminal), the operation terminal 300 includes a display 302 (display device), a microphone 304 (voice input device), a speaker 306 (voice output device), a keyboard 308 (input device), and a mouse 310 (input device). The user can input an instruction to the operation terminal 300 using these devices, and the operation terminal 300 can output the acquired information, notify the state of the magnet, etc. using these devices. The display 302 may be configured as a touch panel type display and used as an input device. Each part of these operation terminals 300 is connected via a bus 322.

[0038] In addition, the operation terminal 300 includes a processor 312 (processor), a ROM 314, and a RAM 316. The above-described remote transmission / reception unit 312A and analysis unit 312B are components of the processor 312. Using such a processor 312, the operation terminal 300 can analyze the urgency and replacement timing of the refrigerator replacement based on the data collected from the operation terminal 200 and display it on the display 302. Similar to the description of the processor 212 above, the processor 312 may have a function of generating an image from measurement data. The recording device 320 includes a non-temporary and tangible recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, and its control unit, and records various types of information. The information recorded in the recording device 320 may be the same as or different from the information recorded in the recording device 220. Information received from a plurality of operation terminals 200 may be recorded in the recording device 320.

[0039] Note that the user can perform the same operations as the operation terminal 200 using the operation terminal 300.

[0040] [Configuration of the Processor in the Operation Terminal] In this embodiment, the hardware structures of the processors 212 and 312 that execute the above-described processing are, for example, various types of processors (processors) as shown below. This "various types of processors" includes a CPU (Central Processing Unit), which is a general-purpose processor that executes software (program) and functions as various processing units, a programmable logic device (PLD) such as an FPGA (Field Programmable Gate Array), which is a processor whose circuit configuration can be changed after manufacture, and a dedicated electric circuit, which is a processor having a circuit configuration designed specifically to execute specific processing, such as an ASIC (Application Specific Integrated Circuit).

[0041] The processor 212 and the processor 312 may be constituted by one of these various processors, or may be constituted by two or more processors of the same or different types (for example, a plurality of FPGAs, or a combination of a CPU and an FPGA). Further, a plurality of processing units (including the arithmetic unit 212A, the remote transmission / reception unit 212B, the remote transmission / reception unit 312A, and the analysis unit 312B) may be constituted by one processor. As an example of constituting a plurality of processing units by one processor, first, as represented by a computer such as a client or a server, one processor is constituted by a combination of one or more CPUs and software, and this processor functions as a plurality of processing units. Second, as represented by a System On Chip (SoC), there is a form in which a processor that realizes the functions of the entire system including a plurality of processing units is used with one IC (Integrated Circuit) chip. Thus, various processing units can be configured by using one or more of the above various processors as a hardware structure.

[0042] Further, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) combining circuit elements such as semiconductor elements. When various processors operate, programs and data recorded in non-temporary and tangible recording media such as ROM 214 and 314 can be referred to, and recording media such as RAM 216 and 316 and internal memories can be used as a temporary working area during operation.

[0043] [Operator's use case] FIG. 5 is a diagram showing the use case of an operator (user) of the magnetic resonance imaging system 10. This use case shows the relationship between the state of the magnetic resonance imaging system 10, the processing in the magnetic resonance imaging system 10, and the operations of the user corresponding to these states and processes. In FIG. 5, the solid line portions indicate the state of the system and the processing of the system (including the output of information), and the dotted line portions indicate the operations (tasks) of the operator.

[0044] [Processing in magnetic resonance imaging system] Next, an aspect of the processing (operation method of the magnetic resonance imaging system 10) in the magnetic resonance imaging system 10 will be described. FIGS. 6 and 7 are flowcharts showing the processing in the magnetic resonance imaging system 10. In the following, mainly the mode in which the operation terminal 200 (on-site operation terminal, first terminal device) performs the processing will be described, but the operation terminal 300 (service site operation terminal, second terminal device) may also perform the processing.

[0045] [User authentication] The processor 212 of the operation terminal 200 authenticates the user (step S100). The processor 212 can authenticate the user by comparing the information input via devices such as the keyboard 208, mouse 210, or microphone 204 (login ID, password, etc.) with the user information 220C (see FIG. 3) recorded in the recording device 220. As illustrated in FIG. 8, the user information 220C is information in which the identification information of the user of the operation terminal 200 and the information indicating the user's job type divided into a plurality of levels are associated. Further, a barcode reader or scanner may be provided on the operation terminal 200 to read the information recorded on an employee ID card or staff ID card and use it for authentication. Biometric authentication of the user (for example, fingerprint, blood vessel pattern, iris, voiceprint, etc.) may be performed. In the magnetic resonance imaging system 10, it is possible to limit the operations that the user can perform according to the user's level (job type) and to set the role of the operation terminal according to the authentication result (described later).

[0046] [Magnet state] The processor 212 acquires magnet data (magnet information 220D in FIG. 3; first information) from the magnetic resonance imaging apparatus 100 (step S110), and determines which of a plurality of states that the magnet 110 can assume is the actual state of the magnet 110 (step S112). The processor 212 can notify the user of the acquired magnet data and the determined actual state of the magnet 110 by means of the display 202, the speaker 206, or the above-described rotating lamp or warning lamp (not shown) (step S114). The magnet data (first information) is a value of a parameter related to the magnet 110 and includes at least one of the temperature of the magnet 110, the current applied to the magnet 110, and the voltage between the lead terminals of the magnet 110. The plurality of states that the magnet 110 can assume are a demagnetized state, a cooling state, a cooled state, an exciting state, and an excited state, and the actual state is one of these plurality of states. Note that the demagnetized state and the cooling state may be integrated into a “cooling state”.

[0047] The above-described magnet data can be measured by the magnet temperature measurement unit 107, the ammeter 108, and the voltmeter 109. As described above with reference to FIG. 3, the value of the parameter related to the magnet 110 and the state of the magnet 110 corresponding to the value of the parameter are associated and recorded in the recording device 220 (see the example in FIG. 10, magnet information 220D), and the processor 212 can determine the actual state of the magnet 110 based on the measured data and this magnet information 220D. Note that the processor 212 may acquire parameters other than the magnet data. In this case, after the processor 212 acquires the magnet data (parameter indicating the state of the magnet 110) and determines the state of the magnet 110, the processor 212 can determine “which parameters other than the magnet data are to be acquired” according to the state of the magnet 110.

[0048] The processor 212 can acquire the values of the above parameters at determined time intervals and make judgments, and can give notifications when the actual state of the magnet 110 changes (for example, when the cooling state changes to the cooled state or when the energized state changes to the energized completed state). The processor 212 may give a notification when the state of the magnet 110 is abnormal. Also, the processor 212 can give a notification by at least one of the display 202 (display device) and the speaker 206 (audio output device).

[0049] Note that it is preferable for the processor 212 to acquire the values of the parameters in real time (without time delay) and make judgments and give notifications about the state of the magnet 110. Also, the processor 212 can notify the remote transmission / reception unit 312A (processor 312) of the operation terminal 300 (operation terminal for service site) of the state of the magnet 110. As one aspect of the notification, the remote transmission / reception unit 312A can display the notified state of the magnet 110 on the display 302, output audio from the speaker 306, or output using the above-mentioned rotating lamp or warning lamp.

[0050] The processor 212 continues the above-mentioned data acquisition, judgment of the state of the magnet 110, and notification until an instruction to start cooling the magnet 110 (until YES in step S120). When the magnet 110 is in the demagnetized state, the processor 212 notifies (display output, audio output) that it is in the demagnetized state.

[0051] [Actions according to the state of the magnet] Note that the processor 212 receives operations according to the actual state of the magnet 110 and transmits instructions corresponding to the received operations to the magnetic resonance imaging apparatus 100. FIG. 9 is a table showing the relationship between the state of the magnet, the information output by the processor 212, the actions required of the user, and the operations received when the actions are executed, and this information is recorded in the recording device 220. The processor 212 determines the actions required of the user with reference to the information in the above table recorded in the recording device 220 according to the actual state of the magnet for at least some of the multiple states that the magnet 110 can assume. Note that FIG. 9 shows cases where actions are required of the user for the cooling completed state and the exciting state, but the processor 212 may require actions of the user for all of the multiple states that the magnet 110 can assume, including other states.

[0052] [Cooling of Superconducting Magnet] [Start of Excitation after Cooling with Liquid Helium Freezing] In the conventional technology using liquid helium, the superconducting magnet was cooled only by pressure (atmospheric pressure). However, with the liquid helium freezing, it became necessary to cool the superconducting magnet with electric power instead of pressure (atmospheric pressure) to maintain the superconducting state. However, when the power supply of the superconducting magnet is turned off for maintenance or the like, the cooling stops, the magnetic field becomes zero (demagnetized state), and the temperature of the superconducting magnet rises. To return to the normal superconducting state from this state, it is necessary to first cool the superconducting magnet and then start excitation. In this embodiment, as described below, safety confirmation is performed during this excitation. Also, the user can perform excitation not only from the local operation terminal but also from a remote operation terminal (such as a service site).

[0053] [Setting of Cooling Curve] When the user instructs the operation terminal 200 to start cooling the magnet 110 (YES in step S120), the processor 212 sets a cooling curve to be used for predicting (calculating) the remaining cooling time in response to the instruction (step S130). The "cooling curve" is information showing the relationship between the time elapsed since the start of cooling the magnet 110 and the temperature of the magnet 110, which is generated based on the measured values, as exemplified in FIG. 10 (cooling curve data 220B in FIG. 3). The "remaining cooling time" is the time (remaining time) required for the magnet 110 to be cooled to the cooled state. The "cooled state" is a state in which the superconducting state of the magnet 110 is maintained and the excitation of the magnet 110 can be started. In the example of FIG. 10, the remaining cooling time 1 corresponds to the magnet temperature 1 and the remaining cooling time 2 corresponds to the magnet temperature 2 in the cooling curve C1.

[0054] FIG. 11 is a diagram showing another example of a cooling curve, and shows cooling curves C2 and C3 for the refrigerators 1 and 2 (cooling devices of different types). The total cooling time (from the start of cooling to the completion of cooling) in the cooling curve C2 is the remaining cooling time 3, and the total cooling time in the cooling curve C3 is the remaining cooling time 4. FIG. 12 is a diagram showing still another example of a cooling curve, and shows a state of obtaining a cooling curve C6 at one year after the start of use by interpolating the cooling curve C4 at the start of use and the cooling curve C5 after three years for the refrigerator 1. The total cooling times corresponding to the cooling curves C4, C5, and C6 are the remaining cooling times 5, 6, and 7, respectively.

[0055] Thus, in the magnetic resonance imaging system 10, it is preferable to store in the recording device 220 data of a plurality of cooling curves according to the type of the cooling device for cooling the magnet 110 and the secular change of the cooling device. The processor 212 preferably interpolates a plurality of cooling curves according to the type of the cooling device and the secular change of the cooling device and uses them for predicting (calculating) the remaining cooling time. By such processing, the remaining cooling time can be accurately predicted. Note that the processor 212 can newly generate a cooling curve based on the measured value of the temperature of the magnet 110 and store the data of the generated cooling curve in the recording device 220. For example, as shown in FIG. 13, a cooling curve C8 based on the measured value can be generated with respect to the cooling curve C7 (prediction curve) and stored in the recording device. The method used for generating a new cooling curve based on the measured value is not particularly limited, but for example, a machine learning method such as the non-linear least squares method can be used. The processor 212 may remove outliers included in the measured value in generating a new cooling curve.

[0056] Note that the processor 212 can display these cooling curves on the display 202 (display device).

[0057] [Calculation and Output of Remaining Cooling Time] In response to an instruction to start cooling, the processor 212 starts cooling the magnet 110 by the compressor 102 and the control unit 103 (step S140), and also acquires the above-described magnet data (step S150). The processor 212 may start cooling the magnet 110 according to an operation by the user of the operation terminal 200, or may automatically start cooling without the user's operation when necessary conditions are satisfied. The processor 212 can regard the fact that the user has operated or the necessary conditions have been satisfied as an "instruction to start cooling". Then, the processor 212 calculates the remaining cooling time using the cooling curve set in step S130 and the acquired magnet data, and outputs the calculated remaining cooling time (step S160). FIG. 14 is a diagram showing an example of displaying the remaining cooling time (the numerical values are examples and do not accurately reflect the cooling time of an actual magnetic resonance imaging apparatus). Not only the remaining cooling time but also the timing at which excitation can be started may be displayed. By these displays, the user can easily grasp the remaining cooling time and the timing at which excitation can be started. In addition to the remaining cooling time, the processor 212 may display (numerical display, graph display, etc.) the set cooling curve and the measured temperature of the magnet 110. By these displays, the user can accurately grasp the state of the magnet 110 and the cooling state, etc.

[0058] [Discrete display, stepwise display of remaining cooling time] The remaining cooling time can be displayed discretely and / or stepwise. For example, the remaining cooling time may be displayed (on display 202) as shown in FIG. 15. In the example of this figure, the processor 212 displays the remaining cooling time (information indicating the remaining cooling time) discretely and stepwise according to the remaining cooling time. Also, as the remaining cooling time approaches zero, a small granularity is determined, and the remaining cooling time is output with the determined granularity. "Granularity" is the output unit of information, and the granularity can be made smaller as the remaining cooling time becomes shorter. Specifically, when the calculated remaining cooling time is one week or more, the processor 212 displays "week" as the granularity (unit). Similarly, when the remaining cooling time is one day or more and less than one week, "day" is displayed as the granularity, and when the remaining cooling time is less than one day, "hour" is displayed as the unit. Also, when the remaining cooling time is "more than one week and less than two weeks", the upper limit value of "about two weeks" is displayed. Furthermore, by adding the phrase "about", it is indicated that the displayed remaining cooling time is approximate. The phrase indicating approximate time may be other phrases such as "approximately", "about", "degree", etc.

[0059] FIG. 16 is a diagram showing another example of discrete display and stepwise display. In the example shown in this figure, the processor 212 rounds the numerical value of the remaining cooling time and displays an approximate time. Rounding the numerical value can be done, for example, by rounding, rounding up, adopting the upper limit value of the range, etc. For example, when the calculated remaining cooling time is 10 days, it can be displayed as "about two weeks". Also, in the example of FIG. 16, similar to the example of FIG. 15, as the remaining cooling time approaches zero, a small granularity is determined, and the remaining cooling time is output with the determined granularity.

[0060] FIG. 17 is a diagram showing an example of discretely displaying the remaining time on the screen. As described above, by adding the phrase "about", it is indicated that the displayed remaining cooling time is approximate.

[0061] For example, even if the difference in the remaining cooling time is 1 hour, there is not much difference between "remaining 1 week" and "remaining 1 week + 1 hour", but there is a significant difference between "remaining 1 hour" and "remaining 2 hours". Therefore, it is preferable to perform the above-described discrete display or stepwise display. Such a display can be performed by recording information indicating the correspondence between the remaining cooling time and the display time, such as in FIGS. 15 and 16, in the recording device 220, and having the processor 212 refer to this information based on the calculated remaining cooling time. The same applies to the operation terminal 300. The user of the operation terminals 200 and 300 may be able to set the granularity of the display.

[0062] The processor 212 repeats the acquisition of the magnet data, the calculation and output of the remaining cooling time until the cooling is completed (until it becomes YES in step S170). The processor 212 can use "the temperature T < T1 continuing for a predetermined time or more" (see FIG. 18) as a requirement for the completion of cooling. When the cooling is completed (YES in step S170), the processor 212 notifies that the cooling is completed (step S180). The notification may be a screen output as shown in FIGS. 14 and 17, or a voice output.

[0063] In the case where some abnormality is detected during the cooling or the like, the user of the operation terminals 200 and 300 can perform an operation to interrupt or stop the cooling.

[0064] [Safety confirmation at the start of excitation] [Two-step safety confirmation: First operation] In the magnetic resonance imaging system 10 according to this embodiment, after the cooling is completed, excitation is started after safety confirmation. This safety confirmation is preferably performed in two steps as described below. FIG. 19 is a diagram showing an example of a screen for two-step safety confirmation. First, when the state of the magnet 110 is in the cooled state by the processing up to step S180, the processor 212 causes the display 202 to display a screen prompting the user to perform a first operation (operation for first safety confirmation) (step S190). The (a) part of FIG. 19 is an example of a screen prompting the first operation (example of output of second information). Unless the user confirms that "there is no magnetic metal or prohibited item in the MR room (examination room)" and "there is no person in the MR room" and checks two check boxes, the "Next" button cannot be pressed. That is, checking the check boxes and pressing the "Next" button constitute the first operation. The user can check and press the button with the mouse 210 (the same applies to the following safety confirmation). Instead of or in addition to the display on the display 202, a message may be output as voice (example of output of second information) from the speaker 206 to prompt the user to perform the first operation.

[0065] Note that FIG. 19 shows an example in which safety confirmation is performed by an operation (an example of the first operation) via the screen of the display 202 (display device), but the user may be able to perform safety confirmation by an operation using voice input via the microphone 204. The operation by voice input can be performed by uttering specific phrases (another example of the first operation) such as, for example, "I have confirmed that there is no magnetic substance" and "I have confirmed that there is no person". Thus, the processor 212 can accept at least one of an operation via the screen of the display device and an operation by voice input as a safety confirmation operation. In this case, it is assumed that the processor 212 has a voice recognition function.

[0066] Also, regarding the above-mentioned safety confirmation, a magnetic substance detection device may be provided outside or at the entrance of the examination room, etc. This device detects magnetic substances (e.g., machines, instruments, tools used in the examination room and its surroundings, or the belongings of the subject, etc.) in the vicinity of the magnetic resonance imaging apparatus 100 and the magnetic resonance imaging apparatus 100, and outputs this detection result (first auxiliary information). Also, the magnetic substance detection device may be provided inside the examination room. In this case, for example, a device that detects magnetic substances based on changes in the voltage between the current lead terminals of the superconducting coil can be used. The processor 212 or the processor 312 may be provided with such a magnetic substance detection function. The output may be a display output to the display 202 or an audio output to the speaker 206. When performing a display output, the name of a typical magnetic substance (e.g., the name of a tool such as a magnetic driver), its image, or an illustration, etc. may be displayed on the display 202, and these pieces of information may be used as auxiliary information (first auxiliary information) for confirming the presence of the magnetic substance. Furthermore, a camera for photographing the magnetic resonance imaging apparatus 100 and its vicinity may be installed, and the photographed image (second auxiliary information) may be displayed on the display 202 and used as auxiliary information (second auxiliary information) during safety confirmation. In the magnetic resonance imaging system 10, it is preferable to output at least one of these first and second auxiliary information during safety confirmation. With these first and second auxiliary information, the user can perform safety confirmation quickly and easily.

[0067] [Two-stage safety confirmation: Second operation] In the state shown in part (a) of FIG. 19, when the user checks two check boxes, the color of the button changes and it becomes pressable (or tappable; the same applies hereinafter) as shown in part (b) of the same figure. When the user presses the button in this state (YES in step S200), the processor 212 causes the display 202 to display a screen (an example of output of the second information) prompting the user to perform a second operation (an operation of second safety confirmation) (step S210). Specifically, the processor 212 causes the display 202 to display the screen illustrated in part (c) of FIG. 19. When the user checks the check box of "Start excitation", the color of the OK button changes as shown in part (d) of the same figure and the user can press it. That is, similar to the first operation described above, checking the check box and pressing the OK button constitute the second operation. When the user presses the OK button in this state, the processor 212 instructs the magnetic resonance imaging apparatus 100 to start excitation, and excitation is started in response to this instruction (step S230). The excitation is automatically executed along a predetermined sequence. During excitation, as shown in FIG. 20, it is preferable to display the remaining excitation time (predicted value) and that entry into the examination room is prohibited. By displaying such remaining excitation time, the user can grasp the timing when the examination can start. Note that the value of the remaining excitation time shown in FIG. 20 is an example and does not accurately reflect the remaining excitation time of an actual magnetic resonance imaging apparatus. Also, the processor 212 may perform discrete display or stepped display for the remaining excitation time in the same manner as described above for the remaining cooling time, and may change the display granularity.

[0068] According to this embodiment, by performing such two-stage safety confirmation so that excitation does not start unless the user checks all items and presses the OK button, safety can be ensured and it is possible to prevent a magnetic substance from being present near the magnetic resonance imaging apparatus 100 and affecting the image quality of the magnetic resonance image.

[0069] [Setting of notification mode according to magnet state, etc.] In addition, the processor 212 preferably sets the notification mode based on the state of the magnet 110 and the content of the action that requests execution from the user. For example, for notifications in a state where safety confirmation is required and care is needed in the operation, such as when exciting the magnet 110, the display mode (e.g., the presence, type, size of characters, symbols, graphics, icons, etc., or the color scheme of the screen, etc.) and the mode of voice output (volume, pitch, output pattern, etc.) are different from those in other states to enhance the degree of attention-grabbing.

[0070] [Cancel safety confirmation] In the above-described safety confirmation, when the user presses the "Cancel" button in the state shown in the (c) part of FIG. 19, the processor 212 returns to step S190 and causes the display 202 to display the screen shown in the (a) part of the figure, and prompts the user to perform the first operation again. That is, when the second operation is canceled, the processor 212 does not instruct the magnetic resonance imaging apparatus 100 to start excitation, but prompts the user to perform the first operation.

[0071] [Excitation completed] The processor 212 determines whether the excitation is completed (step S240). If the excitation is completed (YES in step S240), it notifies (step S250) that the excitation is completed (regarding the success or failure of the excitation) by display or voice. When the excitation is completed (successfully), the magnetic resonance imaging apparatus 100 can image the subject.

[0072] In addition, when some abnormality is detected during the excitation, etc., the user of the operation terminals 200, 300 can perform an operation to interrupt or cancel the excitation. Also, since the magnetic field will disappear if the low-temperature state is not maintained, the cooling state is maintained. For this reason, even after the inspection, power is maintained except for maintenance periods, etc., and the cooling state and the excitation state are maintained.

[0073] [Restrictions on operations according to the user's occupation] [Association between the user's occupation and the operations that the user can perform] In the magnetic resonance imaging system 10 according to the first embodiment, operations that can be executed after the user logs in may be restricted according to the user's occupation (level). When such restrictions on executable operations are provided, for example, in the operation terminal 200, the identification information of the user of the operation terminal 200, the information indicating the user's occupation divided into a plurality of levels, and the information indicating the operations that can be executed by the users belonging to each occupation are associated and stored in the storage device 160. Regarding the relationship between the user's identification information and the user's level and occupation, for example, the association can be performed as shown in FIG. 8. In addition, the operations that can be executed by the users belonging to each occupation can be defined, for example, as shown in the table of FIG. 21. These pieces of information can be recorded in the recording device 220 as user information 220C and specific operation information 220E (see FIG. 3).

[0074] In the example shown in the (a) part of FIG. 21, the user levels are divided by "whether a safety confirmation operation can be performed" and "whether an excitation start operation can be performed". In the example of the same part, it is assumed that a user who cannot perform the safety confirmation operation cannot perform the excitation start operation either. As a result, the users are divided into three levels (upper / middle / lower). Specifically, a user belonging to level 1 (the first level) has the authority to perform the safety confirmation operation of the magnetic resonance imaging apparatus 100 and the excitation start operation of the magnet 110 included in the magnetic resonance imaging apparatus 100. A user belonging to level 2 (the second level) lower than level 1 has the authority to perform the safety confirmation operation but does not have the authority to perform the excitation start operation. A user belonging to level 3 (the third level) lower than level 2 does not have the authority to perform the safety confirmation operation or the excitation start operation.

[0075] In contrast, in the example shown in the (b) part of FIG. 21, among the users of "Level 3", users of a specific occupation (users belonging to the "specific level"; in this example, nurses) are classified so that they can check the remaining cooling time (an example of "information indicating the state of the magnet"). This is assumed for cases where it is necessary to check the state of the magnetic resonance imaging apparatus 100 depending on the occupation. For example, it is conceivable that a user of a specific occupation receives an order of examination content from a doctor and prepares an operation schedule according to the start date of using the magnetic resonance imaging system 10. Note that such a "user of a specific occupation" may be able to check not only the remaining cooling time but also other states of the magnet 110 (any one of a demagnetized state, a cooling state, a cooled state, an exciting state, and an excited state).

[0076] In the example shown in FIG. 21, although there is no restriction on the cooling start operation depending on the occupation, a restriction may be provided in the same manner as other operations.

[0077] As described above, in the magnetic resonance imaging system 10 according to the present embodiment, safety can be improved by restricting the operations executable according to the occupation of the user. Note that also in the operation terminal 300, the operations executable according to the occupation of the user can be restricted in the same manner.

[0078] [Safety Check and Excitation According to User Occupation] FIG. 22 is a flowchart in the case of performing a safety check and excitation according to the occupation of the user. The processing until the safety check operation is performed in step S200 is the same as that in FIGS. 6 and 7, and the same processing is performed at the same step numbers as in FIGS. 6 and 7.

[0079] In the flowchart of FIG. 22, the processor 212 determines whether the user who performed the first operation has the authority to perform the first safety confirmation (confirmation of the absence of a magnetic body and the absence of a person) (step S202). The processor 212 can refer to the tables of FIGS. 8 and 21 described above to determine whether the user has the authority to perform the safety confirmation operation (one aspect of the "specific operation"). When the user does not have the authority for the first safety confirmation (NO in step S202), the processor 212 does not accept the operation that the user attempts to execute and performs the first safety confirmation corresponding process (step S204). "Not accepting the operation" includes, for example, the inability to check the checkbox in the state of FIG. 19 and the inability to press (or tap) the OK button. After executing the first safety confirmation corresponding process in step S204, the process returns to step S200.

[0080] [First Safety Confirmation Corresponding Process] The processor 212 outputs at least one of information indicating that the user does not have the authority to perform the first safety confirmation operation (specific operation) (safety confirmation information 1) and information prompting the upper-level user to perform the first safety confirmation operation (safety confirmation information 2) (step S204). The (a) part of FIG. 23 is a diagram showing an output example of the first safety confirmation corresponding process (an example of outputting both pieces of the above information). Note that in the same part, a situation is assumed in which "Hanako Minami Aoyama" (a nurse), who is a user at level 3, attempts to perform the first safety confirmation operation (specific operation). The processor 212 can display and output the above information on the screen (display 202) of the operation terminal (operation terminal 200; first terminal device) used by the unauthorized user, or may output it as sound via the speaker 206.

[0081] When the user clicks or taps "Request operation" in the same part, an information output request is sent from the processor 212 to the processor 312 (the processor of the operation terminal (here, the operation terminal 300; the second terminal device) used by the upper user). In response, the processor 312 outputs (which may be a display output or an audio output) the information (safety confirmation information 2) illustrated in the (b) part of FIG. 23. Note that the processor 212 may output a message (screen display, audio output) to a mobile terminal (smartphone, tablet terminal; an aspect of the second terminal device) carried by the upper user instead of the operation terminal 300.

[0082] In the state shown in the (b) part of FIG. 23, when the upper user clicks or taps "Confirm safety", a screen as shown in FIG. 19 is displayed on the operation terminal 300 or the mobile terminal, and the first safety confirmation becomes possible.

[0083] Note that in FIG. 23, the case where an unauthorized user uses the operation terminal 200 and the upper user uses the operation terminal 300 is described, but this relationship may be reversed. Also, in FIG. 23, the case where an unauthorized user tries to execute a specific operation is described, but the screen (see FIG. 19) for performing safety confirmation or excitation according to the user level may not be displayed so that a user without permission cannot even try to execute a specific operation.

[0084] [Second safety confirmation corresponding process] Similar to the operation restriction in the first safety confirmation described above, for the operation restriction (steps S222, S224; second safety confirmation corresponding process) in the second safety confirmation (confirmation of excitation start), similar processing can be performed.

[0085] [Role sharing of operation terminal] In the magnetic resonance imaging system 10 according to the present embodiment, the above-described safety check may be performed by only one of the operation terminals 200 and 300, or may be performed by both. When performing the safety check on both operation terminals, one of the operation terminals 200 and 300 (for example, the operation terminal 200 which is the on-site operation terminal) is used as the operation terminal dedicated to the first operation (the first terminal device), and the other (for example, the operation terminal 300 which is the service site operation terminal) can be used as the operation terminal capable of performing the first operation and the second operation (the second terminal device). For example, it is conceivable that a level 2 user (technician) performs the first safety check on the operation terminal 200, and a level 1 user (chief technician) performs the second safety check (and monitoring of the first safety check) on the operation terminal 300. In this case, the operation terminal 200 is the first terminal device, and the operation terminal 300 is the second terminal device. When performing such a role sharing, the screen for the second operation (confirmation and operation of the start of excitation) may not be displayed on the operation terminal 200.

[0086] Further, without fixing which of the operation terminals 200 and 300 is the first terminal device and the second terminal device, the roles may be interchanged according to the level (job type) of the user. For example, it is conceivable to set roles for the operation terminals 200 and 300 according to the ID or job type of the logged-in user.

[0087] [Effects of the Embodiment] As described above, according to the first embodiment, not only professional service personnel having advanced knowledge and technology but also general users can correctly understand the state of the magnet. In addition, since actions such as safety checks are required, the user can easily understand what to do and can surely perform appropriate operations.

[0088] [Others] Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. [Explanation of Reference Numerals]

[0089] 10 Magnetic resonance imaging system 100 Magnetic resonance imaging apparatus 101 Refrigerator 102 Compressor 103 Control unit 104 Pressure measurement unit 106 Shield temperature measurement unit 107 Magnet temperature measurement unit 108 Ammeter 109 Voltmeter 110 Magnet 120 Bed device 200 Operation terminal 202 Display 212 Processor 212A Arithmetic unit 212B Remote transceiver 300 Operation terminal 302 Display 312 Processor 312A Remote transceiver 312B Analysis unit Steps S100 to S250 of the operation method

Claims

1. An operation terminal of a magnetic resonance imaging apparatus, A processor; a non-transitory and tangible recording medium for recording parameter values ​​related to a magnet included in the magnetic resonance imaging apparatus and states of the magnet corresponding to the parameter values ​​in association with each other; Equipped with The processor, obtaining values ​​of the parameters from the magnetic resonance imaging device; determining, based on the acquired values ​​and referring to the recording medium, which of a plurality of possible states of the magnet the actual state of the magnet is; Informing the determined actual state of the magnet. Operation terminal.

2. The operation terminal according to claim 1 , wherein the parameters include at least one of a temperature of the magnet, a current flowing through the magnet, and a voltage between lead terminals of the magnet.

3. 3. The operation terminal according to claim 1, wherein the plurality of states that the magnet can be in are a demagnetized state, a cooling state, a cooling complete state, a magnetized state, and a magnetization complete state.

4. 3. The operation terminal according to claim 1, wherein the magnet is a superconducting magnet for generating a static magnetic field provided in the magnetic resonance imaging apparatus.

5. The operation terminal according to claim 1 , wherein the processor performs the notification through at least one of a display device and a sound output device.

6. 3. The operation terminal according to claim 1, wherein the processor obtains the parameter value at a predetermined time interval to make the judgment, and issues the notification when the actual state of the magnet changes.

7. 3. The operation terminal according to claim 1, wherein the processor receives an operation corresponding to the actual state of the magnet, and transmits an instruction corresponding to the received operation to the magnetic resonance imaging apparatus.

8. The operating terminal of claim 7, wherein the processor prompts a user of the operating terminal to perform an action corresponding to the actual state of the magnet for at least some of the multiple states that the magnet can be in, and accepts the operation when the action is performed.

9. The operation terminal according to claim 8, wherein the processor prompts the user to perform a safety check as the action when the actual state of the magnet is a cooling completion state, and instructs the magnetic resonance imaging device to start exciting the magnet when the safety check is performed.

10. The processor, as the safety confirmation, a first safety check that there is no magnetic material in the vicinity of the magnetic resonance imaging device and that there is no human being in the vicinity of the magnetic resonance imaging device; A second safety check for the start of excitation; The operation terminal according to claim 9, wherein the operation terminal prompts a user to perform the above.

11. the recording medium records the actual state of the magnet and information indicating the action in association with each other; The operation terminal according to claim 8 , wherein the processor determines the action by referring to the recording medium in accordance with the determined actual state of the magnet.

12. A method for operating an operation terminal of a magnetic resonance imaging apparatus, comprising: The operation terminal includes: a processor; and a non-transitory and tangible recording medium for recording parameter values ​​related to a magnet included in the magnetic resonance imaging apparatus and possible states of the magnet in association with each other; The processor, obtaining values ​​of the parameters from the magnetic resonance imaging device; determining, based on the acquired values ​​and referring to the recording medium, which of a plurality of possible states of the magnet the actual state of the magnet is; Informing the determined actual state of the magnet. How it works.

13. An operation terminal according to claim 1 or 2; The magnetic resonance imaging device; A magnetic resonance imaging system comprising:

Images