JP5911338B2 - Magnetic resonance imaging apparatus and cooling apparatus thereof - Google Patents

Description

  Embodiments described herein relate generally to a magnetic resonance imaging apparatus and a cooling apparatus thereof.

  In recent years, with the advancement of technology, the performance of various devices has been improved, and the development of products with higher accuracy and higher functionality than before and the development of products capable of higher speed processing has been actively conducted. ing.

  On the other hand, the pursuit of higher performance of the device is expected to increase the power consumption of the device itself, and the development of a power saving type device and the like is also desired. Specifically, an information processing device that shifts to a power saving mode with low power consumption during an operation standby or an image processing device that shifts to a sleep state when a print job is not received, or a low power consumption than the conventional one. The development of semiconductor devices that perform high-speed computation is underway.

  In addition, technological development to generate electric power has been actively carried out using solar cells that use solar energy as alternative energy (new energy) and thermoelectric conversion modules that use exhaust heat. For example, see Patent Document 1).

  In addition, a magnetic resonance apparatus (Magnetic Resonance Imaging apparatus: also referred to as an MRI apparatus) using a magnetic resonance phenomenon in which magnetism is applied to a human body and hydrogen nuclei in the body resonate has been introduced in hospitals and examination institutions. Similarly, this MRI apparatus is designed to reduce power consumption by reducing the power consumption of the entire MRI apparatus and adopting low power consumption type parts in individual units constituting the MRI apparatus.

JP 2009-105287 A

  By the way, the MRI apparatus cools the heat generated by consuming electric power during examination of a subject using cooling water supplied from a cooling apparatus. Specifically, in the MRI apparatus, the heat generated in the gradient magnetic field coil and the RF amplifier is cooled by circulating cooling water supplied from the cooling apparatus in the apparatus.

  In this case, the cooling device collects the cooling water used for exhaust heat such as the gradient magnetic field coil in its own device, and cools the cooling water that has become hot water for exhaust heat, so that the cooling water again. To the MRI apparatus.

  Here, the inventor of the present application reduces the power consumption of the entire system including the MRI apparatus by reusing the exhaust heat of the cooling water output from the MRI apparatus as part of the power of the MRI apparatus. I found a mechanism to recycle. That is, the present inventor has found an MRI apparatus that reduces the environmental load of the entire system.

According to this embodiment, the magnetic resonance imaging apparatus includes a plurality of constituent units for performing magnetic resonance imaging, a cooling device that cools at least one of the plurality of constituent units with a first refrigerant , and the first The refrigerant is cooled by the second refrigerant, the power generation module generates power using heat generated in the second refrigerant, and the supply means for supplying the generated power to the constituent unit or the storage battery provided in the apparatus And comprising.

The schematic block diagram which showed the structure of the mechanism of cooling of the MRI apparatus which concerns on this embodiment. The block diagram which shows the basic composition of the MRI apparatus which concerns on this embodiment. The block diagram shown about the structure of the gradient magnetic field coil which concerns on this embodiment. Explanatory drawing which showed the internal structure of the gradient magnetic field coil which concerns on this embodiment with the perspective view. The conceptual diagram which showed the relationship between the temperature of the coolant water discharged | emitted from a water circulation circuit, and a time slot | zone in the MRI apparatus which concerns on this embodiment. The conceptual diagram which showed the detail of the temperature change of the cooling water between the time T1 shown in FIG. 5 and the time T2 in the MRI apparatus which concerns on this embodiment. The functional block diagram which showed the structure of the chiller unit which concerns on this embodiment. The flowchart which showed the electric power generation operation | movement process which the chiller unit of the MRI apparatus which concerns on this embodiment generates electric power. In the chiller unit which concerns on this embodiment, explanatory drawing explaining the case where the low temperature end of a power generation module is cooled with external air.

  Hereinafter, an MRI apparatus (magnetic resonance imaging apparatus) 500 according to the present embodiment will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram showing a configuration of a cooling mechanism of the MRI apparatus 500 according to the present embodiment. The MRI apparatus 500 according to the present embodiment includes a cooling device (cooling device for magnetic resonance imaging apparatus) that takes an image of the inside of the subject PT using the magnetic resonance phenomenon and cools the imaging apparatus.

  As shown in FIG. 1, an MRI apparatus 500 includes an MRI gantry 100, an MRI electrical equipment cabinet 200, a cryocooler helium compressor (also simply referred to as a helium compressor) 230, an operation monitoring apparatus 240, a chiller unit 300, a water circulation circuit 400, and the like. It is configured with.

  The MRI gantry 100 includes a gradient magnetic field coil 110. Since the pulse current is repeatedly supplied to the gradient magnetic field coil 110 according to the pulse sequence, heat is generated during imaging. For this reason, the MRI apparatus 500 needs to cool the gradient magnetic field coil 110. Therefore, the gradient magnetic field coil 110 includes a cooling pipe for cooling heat generated during imaging. In the present embodiment, water (hereinafter referred to as refrigerant water (first refrigerant)) is used as the refrigerant, and the refrigerant water circulates through the cooling pipe in the gradient magnetic field coil 110.

  The gradient magnetic field coil 110 is provided with an iron shim in order to correct the non-uniformity of the static magnetic field in the imaging region. When the temperature of the gradient magnetic field coil 110 fluctuates, the permeability of the iron shim changes due to the influence. If the permeability of the iron shim changes, the static magnetic field in the imaging region cannot be kept uniform, and the center frequency may vary.

  Therefore, since the temperature change of the iron shim causes image disturbance, it is necessary to suppress the temperature fluctuation of the gradient coil 110. The MRI gantry 100 including the gradient magnetic field coil 110 is provided in the imaging room.

  The MRI electrical equipment cabinet 200 includes a storage battery 210 and a power redistribution unit 220.

  The storage battery 210 is a storage battery that temporarily stores electric power generated in the chiller unit 300.

  The power redistribution unit 220 supplies the power stored in the storage battery 210 from the storage battery 210 to the operation monitoring device 240 according to the charged state of charge, or supplies power to the entire system (not shown). It is designed to supply power.

  The MRI electrical equipment cabinet 200 is also a unit having a gradient magnetic field power supply 250, a transmission unit 260 constituting an RF amplifier (Radio Frequency amplifier).

  The gradient magnetic field power source 250 is an amplifier that amplifies a pulse current for generating a gradient magnetic field in pulses. The transmission unit 260 has a function of transmitting a high frequency pulse corresponding to the Larmor frequency to the transmission coil. Since the gradient magnetic field power supply 250 and the transmitter 260 also generate heat during imaging, it is necessary to cool the MRI electric equipment cabinet 200 during imaging.

  Note that the gradient magnetic field power supply 250 and the transmission unit 260 do not have to be integrated in the MRI electrical equipment cabinet 200, and may be individually configured as units, and are not particularly limited. Details of the gradient magnetic field power supply 250 and the transmission unit 260 will be described later.

  A cryocooler (not shown) is a cooling device (unit) for cooling liquefied helium stored in a static magnetic field magnet (to be described later) for 24 hours, and is a cold head (or helium) incorporated in the static magnetic field magnet. (Also called an expander) (not shown) and a helium compressor 230. The cryocooler generates a cryogenic temperature by a mechanism in which the high-pressure helium gas produced by the helium compressor 230 adiabatically expands in the expander, keeps the radiation shield inside the magnet at a low temperature, and recycles the gas helium in the helium container inside the magnet. Liquid helium is prevented from evaporating by condensing to produce liquid helium. The liquefied helium inside the magnet is used to cool a superconducting coil (superconducting magnet) described later.

  An operation monitoring device (Magnet Supervisory Unit) 240 is a control device that monitors the pressure of the helium gas and the amount of liquefied helium, and manages the operation of the superconducting coil (superconducting magnet) of the MRI gantry 100.

  The MRI electrical equipment cabinet 200, the cryocooler helium compressor 230, and the operation monitoring device 240 are provided in the machine room.

  The chiller unit 300 is a device that keeps the temperature in the MRI apparatus 500 constant by supplying the coolant water (first coolant) to the water circulation circuit 400 and circulating the coolant water in the MRI apparatus 500. The chiller unit 300 performs cooling of the coolant water circulating through the gradient coil 110 and temperature control of the coolant water, for example. In this case, the chiller unit 300 circulates through the gradient coil 110 and acquires the coolant water that has flowed out of the water circulation circuit 400 as exhaust heat. The chiller unit 300 cools the coolant water and supplies the coolant water to the gradient magnetic field coil 110 as cooling water again. Details of the chiller unit 300 will be described later.

  The water circulation circuit 400 is a path for circulating the coolant water through the MRI apparatus 500. The path of the water circulation circuit 400 is not limited to the gradient magnetic field coil 110. For example, a gradient magnetic field power supply 250 and an RF amplifier (transmitting unit 260) that generate heat can be included in the circulation path of the coolant water. That is, as an element that generates heat when the MRI apparatus 500 is in operation, the gradient circuit 110, the gradient power supply 250, and the transmitter 260 are units to be cooled, and the water circulation circuit 400 is circulated so as to circulate them. You may make it form.

  Next, a basic configuration that configures the MRI apparatus 500 according to the present embodiment will be described.

  FIG. 2 is a configuration diagram showing a basic configuration of the MRI apparatus 500 according to the present embodiment.

  As shown in FIG. 2, the MRI apparatus 500 includes an MRI gantry 100 that includes a static magnetic field magnet 10, a gradient magnetic field coil 110, an RF coil 30, and a top plate 40.

  The static magnetic field magnet 10 includes a substantially cylindrical vacuum vessel 11 and a superconducting coil 12 immersed in a cooling liquid in the vacuum vessel 11, and has a bore (an inside of the cylinder of the static magnetic field magnet 10) as an imaging region. A static magnetic field is generated in the space.

  The gradient magnetic field coil 110 has a substantially cylindrical shape and is fixed inside the static magnetic field magnet 10. The gradient coil 110 has a main coil that applies a gradient magnetic field in the X-axis, Y-axis, and Z-axis directions by a current supplied from the gradient magnetic field power supply 250, and a shield coil that cancels the leakage magnetic field of the main coil. doing. Details of these structures will be described later.

  The RF coil 30 is fixed to the inside of the gradient magnetic field coil 110 so as to face the subject PT. The RF coil 30 irradiates the subject PT with an RF pulse transmitted from the transmitting unit 260, and receives a magnetic resonance signal emitted from the subject PT due to excitation of hydrogen nuclei.

  The top plate 40 is provided on a bed (not shown) so as to be movable in the horizontal direction, and the subject PT is placed and moved into the bore during imaging.

  The gradient magnetic field power supply 250 is a power supply that supplies a current to the gradient magnetic field coil 110 based on an instruction from the sequence control device 280. The gradient magnetic field power supply 250 also has a function of amplifying a current for generating a gradient magnetic field in a pulse shape.

  The transmission unit 260 is a device that transmits an RF pulse to the RF coil 30 based on an instruction from the sequence control device 280. The RF amplifier described above is configured by the transmission unit 260 and transmits a high-frequency pulse to the RF coil 30.

  The receiving unit 270 detects the magnetic resonance signal received by the RF coil 30, digitizes the detected magnetic resonance signal, and transmits the obtained raw data to the sequence control device 280.

  The sequence control device 280 is a device that scans the subject PT by driving the gradient magnetic field power source 250, the transmission unit 260, and the reception unit 270 under the control of the computer system 290. As a result of the scan, When raw data is transmitted from the receiving unit 270, the raw data is transmitted to the computer system 290.

  The computer system 290 is a control device that controls the entire MRI apparatus 500, and is a sequence control that causes the sequence control device 280 to execute a scan based on an input unit that receives various inputs from an operator and an imaging condition input from the operator. Unit, an image reconstruction unit that reconstructs an image based on the raw data transmitted from the sequence control device 280, a storage unit that stores the reconstructed image, and a display that displays various information such as the reconstructed image And a main control unit that controls the operation of each function based on an instruction from the operator.

  Next, the gradient magnetic field coil 110 shown in FIGS. 1 and 2 will be described in detail.

  FIG. 3 is a configuration diagram showing the configuration of the gradient coil 110 according to the present embodiment. FIG. 4 is an explanatory view showing the internal structure of the gradient coil 110 according to the present embodiment in a perspective view.

  As shown in FIG. 3, the gradient magnetic field coil 110 includes a main coil 111, a shield coil 112, a shim tray insertion guide 113, a shim tray 114, and an iron shim 115.

  The gradient magnetic field coil 110 includes a main coil 111 having a substantially cylindrical shape and a shield coil 112. A shim tray insertion guide 113 is formed between the main coil 111 and the shield coil 112.

  The shim tray insertion guide 113 is a through hole of the gradient magnetic field coil 110, and forms an opening over the entire length in the longitudinal direction of the gradient magnetic field coil 110. The shim tray insertion guide 113 is formed at a plurality of locations in the circumferential direction of the gradient magnetic field coil 110 at equal intervals in a region sandwiched between the main coil 111 and the shield coil 112. A shim tray 114 is inserted into each shim tray insertion guide 113.

  The shim tray 114 is made of a resin that is a nonmagnetic and nonconductive material, and has a substantially bar shape. Each of these shim trays 114 stores a predetermined number of iron shims 115. The shim tray 114 is inserted into the shim tray insertion guide 113 and fixed to the central portion of the gradient magnetic field coil 110, respectively.

  The iron shim 115 is provided on the shim tray 114 in order to correct the non-uniformity of the static magnetic field in the imaging region.

  FIG. 4 shows a part of the gradient magnetic field coil 110, in which the upper side in FIG. 4 shows the outer side of the cylindrical shape, and the lower side shows the inner side of the cylindrical shape.

  As shown in FIG. 4, the gradient coil 110 includes inner and outer sides of the shim tray insertion guide 113, that is, between the shim tray insertion guide 113 and the main coil 111 and between the shim tray insertion guide 113 and the shield coil 112. The cooling pipe 116 is embedded in a spiral shape. The basic configuration is the same as that in FIG. 3, and the difference from FIG. 3 is that the cooling pipe 116 is illustrated.

  Cooling water (first refrigerant) is introduced into the cooling pipe 116 from the chiller unit 300 via the water circulation circuit 400, circulates inside the gradient magnetic field coil 110 through the cooling pipe 116, and outside the gradient magnetic field coil 110. Cooling water (refrigerant water) is discharged to Thus, the coolant water cools the gradient magnetic field coil 110 by circulating inside the gradient magnetic field coil 110 through the cooling pipe 116.

  Next, the time zone in which the gradient magnetic field coil 110, the gradient magnetic field power supply 250, the RF amplifier (transmission unit 260), etc. generate heat in the MRI apparatus 500 according to the present embodiment will be described.

  FIG. 5 is a conceptual diagram showing the relationship between the temperature of the refrigerant water discharged from the water circulation circuit 400 and the time zone in the MRI apparatus 500 according to the present embodiment.

  As shown in FIG. 5, the horizontal axis (X axis) is time (T), and the vertical axis (Y axis) is the temperature (U) of the refrigerant water discharged from the water circulation circuit 400. That is, the vertical axis represents the temperature of the coolant water that has flowed into the chiller unit 300.

  FIG. 5 shows that the temperature of the coolant water discharged from the water circulation circuit 400 is high between the time T1 and the time T2 and between the time T3 and the time T4. Specifically, for example, the time T1 is about 8:30 am when the morning inspection starts, and the time T2 is about noon when the morning inspection ends. Time T3 is around 1 pm when the afternoon inspection starts, and time T4 is around 5 pm when the afternoon inspection ends.

  The refrigerant water flows out of the gradient magnetic field coil 110 after the refrigerant water circulates in the gradient magnetic field coil 110 and absorbs heat of the gradient magnetic field coil 110 generated by imaging. For this reason, the temperature of the coolant water is the temperature when it flows into the chiller unit 300 through the water circulation circuit 400. Accordingly, during the time period in which the MRI apparatus 500 is operated and the subject PT is imaged, the gradient magnetic field coil 110 generates heat, and the gradient magnetic field coil 110 is cooled by the coolant water, thereby being discharged as exhaust heat. It shows that the temperature of water is rising.

  Further, since the period from time T2 to time T3 is a time period during which imaging is stopped (during lunch break), the temperature generated by the gradient coil 110 or the like temporarily decreases. In addition, when the afternoon inspection is started from time T3, the temperature of the discharged coolant water is high (about 45 degrees) until time T4. Next, details of the time zone in which the temperature of the coolant water is rising will be described.

  FIG. 6 is a conceptual diagram showing details of the change in the temperature (U) of the cooling water between time T1 and time T2 shown in FIG. 5 in the MRI apparatus 500 according to the present embodiment.

  As shown in FIG. 6, there are four high temperature periods between time T1 and time T2. This indicates that the temperature of the coolant water is high while the four subjects (PT1 to PT4) are imaged, while these subjects are being imaged. In particular, regarding the imaging of the subject PT1 and the subject PT2, the temperature is temporarily changed by changing the imaging method or changing the imaging settings.

  The temperature (U) of the coolant water shown in FIG. 5 and FIG. 6 is about 45 ° C. at a high temperature and about 20 ° C. at a low temperature, but is illustrative and not limited thereto. In addition, during the time period when the MRI apparatus 500 is not operating, the MRI apparatus 500 is cooled by various cooling devices. Therefore, the MRI apparatus 500 is kept cold at a constant temperature of about 20 ° C. during a time period when the MRI apparatus 500 is not operating.

  In addition to the above embodiment, the present embodiment is characterized in that the chiller unit 300 further includes a power generation module. Details of the chiller unit 300 will be described.

  FIG. 7 is a functional block diagram showing a configuration of the chiller unit 300 according to the present embodiment.

  As shown in FIG. 7, the chiller unit 300 includes a temperature sensor 305, an evaporator 310, a compressor 320, a condenser 330, an expander 340, a refrigerant gas circulation circuit 350, and a power generation module 360.

  The temperature sensor 305 is a sensor that measures the temperature when refrigerant water (first refrigerant) that circulates through the gradient magnetic field coil 110 of the MRI gantry 100 and flows out of the water circulation circuit 400 flows into the chiller unit 300. In the present embodiment, the operating status of the MRI gantry 100 and the gradient magnetic field coil 110 is determined based on the temperature of the coolant water that has flowed into the chiller unit 300. Note that the temperature sensor 305 need not be provided as long as the chiller unit 300 can acquire information regarding the operating state of the MRI gantry 100 and the gradient coil 110.

  The evaporator 310 is a heat exchanger having a function by absorbing heat from the refrigerant water (first refrigerant) of hot water carried by exhaust heat. The liquefied refrigerant becomes a low-temperature and low-pressure gas (gas) when absorbing heat from the refrigerant water of hot water. For example, HCFC (hydrochlorofluorocarbons) or HFC (hydrofluorocarbons) is used as the liquefied refrigerant. Since these have a boiling point of about −50 ° C. or about −80 ° C., the refrigerant water is cooled and evaporated by absorbing heat from the refrigerant water (first refrigerant).

  Specifically, in the evaporator 310, when the coolant water flows into the chiller unit 300 at 45 ° C., the liquefied coolant cools the coolant water so that the coolant water becomes approximately 20 ° C. coolant. At the same time, the liquefied refrigerant evaporates and vaporizes.

  The compressor 320 is a machine having a function of compressing evaporated refrigerant gas (second refrigerant) and sending it out as a high-temperature and high-pressure gas. Note that the vicinity of the output of the compressor 320 is at a high temperature, specifically, a high temperature state of about 60 ° C. (or about 80 ° C.). In addition, this temperature differs according to the specification of the compressor to be used, and is not particularly limited.

  The condenser 330 is a heat exchanger that releases the heat of the high-temperature and high-pressure gas to the atmosphere and liquefies the low-temperature and high-pressure. In order to efficiently perform heat exchange, the chiller unit 300 may be provided with a window for intake and exhaust or a heat dissipation fan.

  The expander 340 has a function of expanding the liquefied liquefied refrigerant to change from a low temperature high pressure liquid to a low temperature low pressure liquid.

  The refrigerant gas circulation circuit 350 is a liquefied refrigerant circulation circuit that absorbs heat and discharges the heat to the atmosphere with respect to the hot water refrigerant water that has flowed from the water circulation circuit 400.

  The power generation module 360 is a thermoelectric generation module that generates power using heat generated when the refrigerant gas is compressed by the compressor 320. In this chiller unit 300, by connecting the high temperature end of the power generation module 360 in the vicinity of the output side of the compressor 320, the heat on the output side of the compressor 320 that becomes high temperature is effectively used to efficiently generate power. be able to.

  On the other hand, the low temperature end of the power generation module 360 is connected to the cold plate 370 by providing a thermal anchor (fixing bolt) using a copper member with high thermal conductivity at a depth of about 5 m in the ground. . Since the underground temperature (geothermal) has a small fluctuation of about 15 ° C. throughout the year, a stable temperature difference can be obtained by using the underground temperature at the low temperature end of the power generation module 360.

  Specifically, a temperature difference of about 45 ° C. can be obtained between about 60 ° C. at the high temperature end of the power generation module 360 and about 15 ° C. of geothermal heat. In addition, in this embodiment, it is not limited to a heat anchor, For example, the low temperature part which uses a heat pipe 365 and exchanges geothermal heat as heat sinks, such as a heat radiator and a heat sink, may be sufficient.

  As described above, when the power generation module 360 generates power using the temperature difference between the high temperature end and the low temperature end, power is stored in the storage battery 210 (FIG. 1). Further, in the chiller unit 300, a temperature difference occurs in the coolant water (first coolant) while the gradient magnetic field coil 110 is operated and imaging is performed, and the power generation module 360 can generate power. 1) can be efficiently generated.

  The chiller unit 300 includes a water supply pump (not shown) that circulates coolant water, and includes a function of supplying coolant water to the gradient magnetic field coil 110 via the water circulation circuit 400.

  Next, a power generation operation process in which the chiller unit 300 of the MRI apparatus 500 according to the present embodiment generates electric power will be described.

  FIG. 8 is a flowchart showing a power generation operation process in which the chiller unit 300 of the MRI apparatus 500 according to the present embodiment generates power. It is assumed that the water circulation circuit 400 circulates so as to cool the gradient magnetic field coil 110 as an example.

  When the computer system 290 (FIG. 2) receives an operation instruction from the operator, the MRI apparatus 500 starts imaging (scanning) of the subject PT (step ST001). In this case, the computer system 290 controls the gradient magnetic field coil 110 via the sequence controller 280 to perform scanning. In the MRI apparatus 500, the gradient magnetic field coil 110 generates heat by imaging the subject PT.

  In the MRI apparatus 500, cooling water (refrigerant water) is supplied from the chiller unit 300 to the gradient coil 110 via the water circulation circuit 400. The cooling water cools the generated gradient magnetic field coil 110. The cooling water that has absorbed the heat becomes warm water and flows out of the gradient coil 110 through the cooling pipe 116 (FIG. 4) and the water circulation circuit 400. The cooling water that has become hot water flows into the chiller unit 300. Thereby, chiller unit 300 acquires the waste heat water (warm water) of gradient magnetic field coil 110 (step ST003).

  When the chiller unit 300 acquires the exhaust heat water (refrigerant water), the liquefied refrigerant (second refrigerant) absorbs heat from the exhaust heat water (first refrigerant) in the evaporator 310 (FIG. 7), The exhaust heat water is cooled (step ST005). The cooled exhaust heat water becomes cooling water, and circulates again through the cooling pipe 116 of the gradient magnetic field coil 110 through the water circulation circuit 400 to cool the gradient magnetic field coil 110. On the other hand, the liquefied refrigerant (second refrigerant) evaporates into a low-temperature and low-pressure gas.

  Chiller unit 300 compresses the evaporated refrigerant gas (second refrigerant) in compressor 320 (FIG. 7) to a high temperature and high pressure (step ST007).

  In the chiller unit 300, the power generation module 360 connected to the high temperature side of the compressor 320 and the ground generates power (step ST009), and the generated power is stored in the storage battery 210 of the MRI electrical equipment cabinet 200. The power redistribution unit 220 allocates the power stored in the storage battery 210 to the power of a control unit or the like that controls the operation monitoring device 240 or the MRI electrical equipment cabinet 200 in accordance with the state of charge of the storage battery 210.

  The chiller unit 300 releases the heat of the compressed refrigerant gas (cooling) in the condenser 330 (FIG. 7) to form a low-temperature high-pressure liquid (step ST011).

  The chiller unit 300 expands the liquefied refrigerant that has become the low-temperature and high-pressure liquid in the expander 340 (FIG. 7) to low temperature and low pressure (step ST013).

  In the present embodiment, the chiller unit 300 continuously cools the exhaust heat water (warm water) that flows in through the water circulation circuit 400, and supplies it to the gradient coil 110 as cooling water. ing.

  The chiller unit 300 continuously acquires the exhaust heat water (step ST015), and the temperature sensor 305 (FIG. 7) continuously monitors the temperature of the exhaust heat water (step ST017).

  Here, if the acquired exhaust heat water is equal to or higher than the predetermined temperature (Yes in step ST017), the chiller unit 300 proceeds to step ST005 and continues the cooling process of the exhaust heat water. For example, when the exhaust heat water is 25 ° C. or higher, the chiller unit 300 can be set to continue the process of cooling the gradient magnetic field coil 110.

  On the other hand, when the acquired waste heat water is lower than the predetermined temperature (No in step ST017), the chiller unit 300 determines that the operation of the gradient magnetic field coil 110 is finished and the imaging by MRI is finished (step ST019). ), The power generation operation process is terminated.

  In this case, for example, when the temperature of the exhaust heat water is 20 ° C., the chiller unit 300 can determine that the gradient coil 110 is not in operation, and can determine that imaging by the MRI apparatus has ended.

  As described above, in the MRI apparatus 500 according to the present embodiment, when the gradient magnetic field coil 110 in the MRI gantry 100 generates heat, the exhaust heat water that exhausts the generated heat is cooled, and the compressor generated at that time is cooled. Since the power generation module 360 can generate power using this temperature difference, it is possible to generate power efficiently when the MRI apparatus 500 is in operation.

  Thereby, the electric power generated by the power generation module 360 is accumulated in the storage battery 210, and can be used, for example, for control of the operation monitoring device 240 according to the state of charge of the storage battery 210. The power consumption of the entire system can be efficiently reduced.

  In addition, the power generated by the power generation module 360 is not limited to the control of the operation monitoring device 240. For example, the control of the gradient magnetic field power supply 250 and the gradient magnetic field power supply 250 and the control of the RF amplifier (transmission unit 260) are performed. Therefore, it can be used for the power of the control circuit and other devices that can cover the power consumption according to the amount of power generation.

  Further, since the power redistribution unit 220 can distribute the power stored in the storage battery 210 based on the state of charge of the storage battery 210 and the power generation performance of the power generation module 360, for example, relative power consumption The power supply is not limited to a small number of control devices, but by improving or improving the power generation performance, the balance between power consumption and supply power can be determined and power can be supplied to power sources within the supply range. It can also be used as a power source. Further, it can be applied to an uninterruptible power supply (so-called UPS) as backup power for a computer unit of the MRI electrical equipment cabinet 200 or the like.

  In this embodiment, when the high temperature end of the power generation module 360 is about 60 ° C., the geothermal heat is about 15 ° C., and thus a temperature difference of about 45 ° C. can be obtained. When applied to a currently available power generation module in the case of a temperature difference of about 45 ° C., power generation of about 2 watts [W] can be expected.

  By the way, when using geothermal heat like this embodiment, the construction which installs a heat anchor etc. may be needed. Therefore, the case where the cold end is generated by the outside air without the need for construction is examined.

  FIG. 9 is an explanatory diagram illustrating a case where the low temperature end of the power generation module 360 is cooled by outside air in the chiller unit 300 according to the present embodiment.

  In the above-described embodiment, the low-temperature end of the power generation module 360 is embedded in the ground. For example, as illustrated in FIG. 9, a cold plate 370 provided in the heat pipe 365 is connected to the outside air ( The low temperature end of the power generation module 360 may be configured by providing the air intake) around the intake port or the intake fan 380. In this case, it is possible to avoid the construction (work) of burying the thermal anchor in the ground, and the low temperature end can be easily realized simply by providing the cooling plate 370 around the intake port or the intake fan 380.

  When using the temperature of the outside air, for example, if the outside air temperature is about 30 ° C., the temperature difference of about 30 ° C. can be obtained because the high temperature end of the power generation module 360 is about 60 ° C. When applied to currently available power generation modules in the case of a temperature difference of about 30 ° C., power generation of about 1 watt [W] can be expected.

  In the above-described embodiment, the power generation module 360 is provided in the vicinity of the output side of the compressor 320. In addition to this, for example, the water circulation circuit 400 that circulates in the chiller unit 300 is also connected to the evaporator. A power generation module may be added so as to generate power using the difference between the temperature of the coolant water before cooling the coolant water at 310 and the temperature of the coolant water after cooling at the evaporator 310.

  In the present embodiment, the temperature sensor 305 of the chiller unit 300 is configured to determine the operating status of the MRI gantry 100 and the gradient coil 110 based on the temperature of the cooling water flowing from the water circulation circuit 400. It is not limited to this. For example, the chiller unit 300 may include a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a network interface, etc., not shown, instead of the temperature sensor 305.

  Specifically, the chiller unit 300 communicates with the MRI gantry 100 and the MRI electrical equipment cabinet 200 via a network interface, and according to the operating conditions of the gradient magnetic field coil 110 and the transmitter 260 that constitutes the RF amplifier. Thus, evaporation of the liquefied refrigerant circulating in the refrigerant gas circulation circuit 350 is controlled.

  In this case, the CPU can realize the evaporation control process of the liquefied refrigerant by loading various programs stored in the ROM into the RAM and developing the programs. The RAM is used as a work area (working memory). The ROM stores various programs. The various programs stored in the ROM include programs for realizing the temperature adjustment process of the cooling water (first refrigerant), the evaporation control process of the liquefied refrigerant, and the power generation control process of the power generation module 360.

  By processing such a program with the CPU, the chiller unit 300 can also reduce energy loss when the evaporator 310 evaporates the liquefied refrigerant.

  In the above-described MRI apparatus 500 according to the present embodiment, the system including the chiller unit 300 has been described. However, the present invention is not limited to this. For example, the chiller unit 300 liquefies the water circulation circuit 400 (refrigerant circulation unit) that circulates coolant water (first refrigerant) in the gradient magnetic field coil 110 and the coolant water (first refrigerant) that circulates in the gradient magnetic field coil 110. A cooling device including a power generation module 360 that cools with a refrigerant (second refrigerant) and generates power using a temperature difference generated in the liquefied refrigerant can be realized alone.

  Further, the chiller unit 300 according to this embodiment described above does not have to be provided as a whole, and for example, the condenser 330 may be provided outdoors. That is, even if each component which comprises the chiller unit 300 is each comprised separately, if the chiller unit 300 contains the component which has each function, it can implement | achieve.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  Further, in the embodiment of the present invention, each step of the flowchart shows an example of processing that is performed in time series in the order described. The process to be executed is also included.

DESCRIPTION OF SYMBOLS 10 Static magnetic field magnet 11 Vacuum vessel 12 Superconducting coil 30 RF coil 40 Top plate 100 MRI gantry 110 Gradient magnetic field coil 111 Main coil 112 Shield coil 113 Shim tray insertion guide 114 Shim tray 115 Iron shim 116 Cooling pipe 200 MRI electric equipment cabinet 210 Storage battery 220 Electric power Redistribution unit 230 Cryocooler helium compressor 240 Operation monitoring device 250 Gradient magnetic field power supply 260 Transmitter 270 Receiver 280 Sequence controller 290 Computer system 300 Chiller unit 305 Temperature sensor 310 Evaporator 320 Compressor 330 Condenser 340 Expander 350 Refrigerant Gas circulation circuit 360 Power generation module 365 Heat pipe 370 Cold plate 380 Intake fan 400 Water circulation circuit 500 MRI apparatus PT Subject

Claims (7)

A plurality of constituent units for performing magnetic resonance imaging; and
A cooling device that cools at least one of the plurality of constituent units with a first refrigerant ;
A power generation module that cools the first refrigerant with a second refrigerant and generates power using heat generated in the second refrigerant;
Supply means for supplying the generated power to the constituent unit or a storage battery provided in the apparatus;
A magnetic resonance imaging apparatus comprising: The power generation module is:
The magnetic resonance imaging apparatus according to claim 1, wherein a high-temperature side terminal of the power generation module is connected in the vicinity of an output of a compressor that compresses the second refrigerant in the cooling device. One of the plurality of constituent units is a gradient coil,
The power generation module is:
The magnetic resonance imaging apparatus according to claim 1, wherein the gradient coil generates power when a gradient magnetic field is applied to a subject. And the storage battery for storing electric power,
A power distribution unit that distributes the power stored in the storage battery, and
The storage battery is
Storing the power generated by the power generation module;
The power distribution unit
The electric power for monitoring the said operation is supplied from the said storage battery to the operation monitoring apparatus which monitors the driving | operation of the said gradient magnetic field coil according to the charge condition stored in the said storage battery. The magnetic resonance imaging apparatus described in 1. The power generation module is:
The low temperature part which becomes the low temperature side using the temperature of geothermal heat is formed by the buried heat conductor in the ground, and the low temperature side terminal of the power generation module is connected to the low temperature part. The magnetic resonance imaging apparatus described in 1. The power generation module is:
The low temperature part which becomes a low temperature side is formed using the temperature of the outside air which the cooling device inhales, and the low temperature side terminal of the power generation module is connected to the low temperature part. Magnetic resonance imaging equipment. A cooling unit that cools at least one of the plurality of constituent units of the magnetic resonance imaging apparatus with a first refrigerant;
A power generation module that cools the first refrigerant with a second refrigerant and generates power using heat generated in the second refrigerant;
Supply means for supplying the generated power to a storage battery provided in the constituent unit or the magnetic resonance imaging apparatus;
A cooling apparatus for a magnetic resonance imaging apparatus.

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