Mobile X-ray CT Examination Vehicle

Abstract

To reduce volume and weight of an object to be loaded on an X-ray CT mobile examination car.SOLUTION: An X-ray CT mobile examination car comprises a power storage unit, a converter, a wheel, and a CT rotation unit. The power storage unit stores electric energy. The converter controls charging to the power storage unit and discharging. The wheel rotates on the basis of output from the converter. The CT rotation unit rotates on the basis of the output from the converter.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to a mobile X-ray CT examination vehicle.

Background Art

[0002] Mobile examination refers to a form of health examination in which a vehicle equipped with medical devices for performing examinations (hereinafter also referred to as a mobile examination vehicle) moves to a region, workplace, etc., and conducts examinations at the destination. As this type of medical device, in-vehicle X-ray devices, X-ray CT (computed tomography) devices, etc. are known. Also, as the technology of this type of vehicle, methods using electric energy without relying on internal combustion engines, such as electric vehicles EV (electric vehicle) and fuel cell vehicles FCV (fuel cell vehicle), are known. Further, as a method of obtaining electric power for medical devices, a method of mounting a generator or a battery on the mobile examination vehicle is known.

[0003] However, among the methods of obtaining electric power for medical devices, the method of mounting a generator is not suitable for mobile examinations because exhaust gas and noise are generated from the generator during the examination. Also, the method of mounting a battery does not generate exhaust gas, etc., but if the output density and energy density of the battery are not high, the occupied volume and weight increase, which is disadvantageous for movement. For this reason, in the method of mounting a battery, it is necessary to reduce the volume and weight of the items mounted on the mobile examination vehicle. In particular, when the medical device is a large device such as an X-ray CT device, there is a high need to reduce the volume and weight of the items mounted on the mobile examination vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to reduce the volume and weight of the equipment mounted on the mobile X-ray CT examination vehicle. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. The problems corresponding to the effects of each configuration shown in the embodiments described below can also be regarded as other problems.

Means for Solving the Problems

[0006] The mobile X-ray CT examination vehicle according to the embodiment includes a power storage unit, a converter, wheels, and a CT rotating unit. The power storage unit stores electrical energy. The converter controls charging and discharging to the power storage unit. The wheels rotate based on the output from the converter. The CT rotating unit rotates based on the output from the converter.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0008] Hereinafter, the X-ray CT mobile examination vehicle according to each embodiment will be described with reference to the drawings. In the following description, the same reference numerals are given to substantially the same parts between different drawings, and the description of overlapping explanations is omitted.

[0009] <First Embodiment> FIG. 1 is a block diagram showing an example of the configuration of an X-ray CT mobile examination vehicle according to the first embodiment. In this X-ray CT mobile examination vehicle 100, an X-ray CT device is mounted on a fuel cell vehicle (FCV) using hydrogen as an energy source. The X-ray CT mobile examination vehicle 100 includes a power supply system including a hydrogen tank 1, a fuel cell 2, a power storage unit 12, and a power control unit 15 as a common mechanism for the fuel cell vehicle (FCV) and the X-ray CT device, and a drive system including a motor 5 and a drive transmission (transmission) mechanism 6. Further, the X-ray CT mobile examination vehicle 100 includes wheels 7 as a configuration specific to the fuel cell vehicle (FCV). Further, the X-ray CT mobile examination vehicle 100 includes a drive transmission (transmission) mechanism 26, a CT gantry 27, a slip ring 30, an inverter 31, a high voltage generator 32, an X-ray tube 33, a DCDC converter 41, in-CT-gantry equipment 42, a converter 51, and CT fixed part equipment 52 as a configuration specific to the X-ray CT device.

[0010] Here, the hydrogen tank 1 stores hydrogen. As a hydrogen storage method, for example, a high-pressure hydrogen tank method in which gaseous hydrogen is compressed at high pressure and stored is used. However, the present invention is not limited to this, and other methods such as a liquid hydrogen tank method for storing liquid hydrogen or a hydrogen storage alloy method for absorbing hydrogen into a metal can also be used.

[0011] The fuel cell 2 converts the hydrogen in the hydrogen tank 1 into electrical energy. Specifically, the fuel cell 2 converts the hydrogen stored in the hydrogen tank 1 into electrical energy and outputs a DC voltage to the boost converter 3. As the fuel cell 2, for example, a polymer electrolyte fuel cell (PEFC) or the like can be appropriately used.

[0012] The boost converter 3 boosts the voltage of the fuel cell 2. That is, the boost converter 3 boosts the DC voltage output from the fuel cell 2 and supplies it to the converter 13. Specifically, the boost converter 3 boosts the DC voltage when the DC voltage output from the fuel cell 2 is lower than the desired voltage.

[0013] The power storage unit 12 stores electrical energy. Specifically, the power storage unit 12 is a power storage device composed of a secondary battery or a capacitor that stores electrical energy, and charging (power storage) or discharging (voltage output) is controlled by the converter 13. As the capacitor, for example, an EDLC (electrical double layer capacitor) or the like can be appropriately used.

[0014] The converter 13 controls the charging and discharging of the power storage unit 12. Further, the converter 13 outputs an output based on the output of the power storage unit 12 and the output from the boost converter 3. For example, the converter 13 converts the DC voltage received from the boost converter 3 and / or the power storage unit 12 into an appropriate DC voltage and outputs it to the inverter 4, the slip ring 30, and the converter 51. Specifically, the converter 13 outputs an appropriate DC voltage to the inverter 4 when the vehicle is running. Also, the converter 13 outputs an appropriate DC voltage to the inverter 4, the slip ring 30, and the converter 51 during CT examination. Further, the converter 13 charges the power storage unit 12 with the electrical energy (regenerative energy) of the regenerative power received from the inverter 4 when the X-ray CT mobile examination vehicle 100 decelerates or when the CT gantry 27 rotates and decelerates.

[0015] The inverter 4 converts the DC output of the converter 13 into AC. Specifically, the inverter 4 converts the DC voltage output from the converter 13 into an AC voltage and outputs the obtained AC voltage to the motor 5.

[0016] Note that the boost converter 3, converter 13, and inverter 4 constitute a power control unit 15 for converting the DC electrical energy received from the fuel cell 2 or the power storage unit 12 and outputting it to the motor 5, slip ring 30, or converter 51.

[0017] The power control unit 15 includes a processor (not shown) for appropriately adjusting the power of the mobile X-ray CT examination vehicle 100, and controls the boost converter 3, converter 13, and inverter 4. For example, when the vehicle is running, the processor of the power control unit 15 monitors the remaining hydrogen amount in the hydrogen tank 1 and the remaining power storage amount in the power storage unit 12, and based on the monitoring results and the rotation status of the wheel 7, changes the usage distribution between the fuel cell 2 and the power storage unit 12 to conserve the remaining hydrogen amount, thereby controlling the boost converter 3, converter 13, and inverter 4. Also, for example, when performing a CT diagnosis, the processor of the power control unit 15 monitors the remaining hydrogen amount in the hydrogen tank 1 and the remaining power storage amount in the power storage unit 12, and based on the monitoring results, the rotation status of the CT gantry 27, and the X-ray output conditions, changes the usage distribution between the fuel cell 2 and the power storage unit 12 to conserve the remaining hydrogen amount, thereby controlling the boost converter 3, converter 13, and inverter 4.

[0018] Also, the inverter 4 converts the regenerative power generated by the motor 5 during deceleration of the mobile X-ray CT examination vehicle 100 or during rotational deceleration of the CT gantry 27 into DC, and supplies the DC regenerative power to the converter 13. For example, the inverter 4 includes a circuit in which a plurality of arms with diodes connected in anti-parallel to switching elements are bridge-connected. In this case, when the motor 5 becomes a generator, all the switching elements of the inverter 4 are turned off, and the inverter 4 functions as a rectifier circuit with the diodes bridge-connected. Therefore, the inverter 4 converts the regenerative power generated by the motor 5 into DC.

[0019] The motor 5 is rotationally controlled by the inverter 4. Specifically, the motor 5 is rotationally controlled by the AC output of the inverter 4 and outputs a rotational driving force to the drive transmission (speed change) mechanism 6. When the drive transmission (speed change) mechanism 6 is omitted, the motor 5 is rotationally controlled by the AC output of the inverter 4 and outputs a rotational driving force to the wheel 7 and the drive transmission (speed change) mechanism 26.

[0020] Also, when the X-ray CT mobile examination vehicle 100 decelerates, the motor 5 rotates in response to the rotational driving force received from the wheel 7 via the drive transmission (speed change) mechanism 6, thereby generating regenerative power and supplying it to the inverter 4 to become a generator. Similarly, when the rotation frame in the CT gantry 27 decelerates, the motor 5 rotates in response to the rotational driving force received from the CT gantry 27 via the drive transmission (speed change) mechanism 26, thereby generating regenerative power and supplying it to the inverter 4 to become a generator.

[0021] The drive transmission (speed change) mechanism 6 transmits the rotational driving force of the motor 5 to the wheel 7 and the drive transmission (speed change) mechanism 26. When the inverter 4 appropriately rotationally controls the motor 5, the drive transmission (speed change) mechanism 6 has the speed changer omitted and is provided as a drive transmission mechanism.

[0022] The wheel 7 rotates based on the output from the converter 13. For example, the wheel 7 rotates based on the output from the inverter 4 that converts the DC output of the converter 13 into AC. Also for example, the wheel 7 rotates based on the output from the motor 5 whose rotation is controlled by the inverter 4. Also for example, the wheel 7 rotates by the rotational driving force of the motor 5 transmitted from the drive transmission (speed change) mechanism 6. However, the wheel 7 may be deformed into a configuration where it rotates by the rotational driving force of the motor 5 without necessarily passing through the drive transmission (speed change) mechanism 6. This modification example is the case of an in-wheel motor in which the wheel 7 and the motor 5 are integrated. In the case of an in-wheel motor, the inverter 4, the motor 5, and the wheel 7 are provided for each drive wheel. For example, in the case of a four-wheel four-wheel drive vehicle, four inverters 4, four motors 5, and four wheels 7 are provided. In this case, the four inverters 4 individually output an AC voltage to the four motors 5, and each motor 5 individually rotates each wheel 7. Supplementary explanation: In the case of an in-wheel motor, basically, the number of inverters 4 required is equal to the number of motors 5 that rotate simultaneously, and the control of the inverters 4 is independent control. This is because there is an inside wheel difference when the traveling direction of the vehicle turns, so the four wheels are driven individually. Note that the in-wheel motor is applicable not only to the aforementioned four-wheel four-wheel drive but also to any drive system. For example, the in-wheel motor may be applied to any all-wheel drive such as a six-wheel six-wheel drive or an eight-wheel eight-wheel drive, or may be applied to a front-wheel drive (FF) or a rear-wheel drive (FR) such as a four-wheel two-wheel drive. Alternatively, the in-wheel motor may be applied to an irregular drive system such as the two-motor drive part of a four-wheel three-motor drive (e.g., one motor for the front wheels and two motors for the rear wheels). Note that the possibility of modification examples of the in-wheel motor is the same in each of the following embodiments.

[0023] The drive transmission (speed change) mechanism 26 is a mechanism such as a shaft and a belt for changing the wheel rotation driving force of a vehicle and rotating the CT. It transmits the rotational driving force of the motor 5 transmitted from the drive transmission (speed change) mechanism 6 to the CT gantry 27. Since the motor 5 is arranged at a position suitable for the running of the mobile X-ray CT examination vehicle, there is a distance between the drive transmission (speed change) mechanism 6 of the motor 5 and the CT gantry 27. For this reason, a drive transmission (speed change) mechanism 26 is provided between the drive transmission (speed change) mechanism 6 and the CT gantry 27. However, the drive transmission (speed change) mechanism 26 may transmit the rotational driving force of the motor 5 to the CT gantry 27 without necessarily passing through the drive transmission (speed change) mechanism 6. For example, when the drive transmission (speed change) mechanism 6 is omitted, the drive transmission (speed change) mechanism 26 transmits the rotational driving force of the motor 5 to the CT gantry 27. Also, when the inverter 4 appropriately controls the rotation of the motor 5, the drive transmission (speed change) mechanism 26 can omit the speed changer.

[0024] The CT gantry 27 rotates based on the output from the converter 13. For example, the CT gantry 27 rotates based on the output from the inverter 4 that converts the DC output of the converter 13 into AC. Also for example, the CT gantry 27 rotates based on the output from the motor 5 whose rotation is controlled by the inverter 4. Also for example, the CT gantry 27 rotates by the rotational driving force of the motor 5 transmitted from the drive transmission (speed change) mechanism 26. When the CT gantry 27 rotates, specifically, the rotating frame inside the CT gantry 27 rotates. The rotating frame is an annular frame that supports the X-ray tube 33 and the X-ray detector facing each other and rotates the X-ray tube 33 and the X-ray detector. The rotating frame further supports, in addition to the X-ray tube 33 and the X-ray detector, an inverter 31, a high-voltage generator 32, and a DAS (data acquisition system). The CT gantry 27 (the rotating frame inside) is an example of the CT rotating part. The X-ray detector and the DAS are examples of the in-CT-gantry equipment 42 described later.

[0025] The slip ring 30 sends the DC voltage output from the converter 13 to the inverter 31 and the DC-DC converter 41 mounted on the rotating frame within the CT gantry 27. The slip ring 30 sends the DC voltage from the fixed frame to the rotating frame by the slider (brush) contacting the boundary between the fixed frame where the DC voltage is input and the rotating frame. Specifically, the slip ring 30 is a member for supplying power from the fixed frame side to the components on the rotating frame side, and has a brush provided on the fixed frame for power supply and a ring provided on the rotating frame for receiving power supply from the brush. Note that the fixed frame is a non-rotating member that rotatably supports the rotating frame.

[0026] The inverter 31 is provided on the rotating frame and converts the DC voltage sent from the slip ring 30 into AC.

[0027] The high-voltage generator 32 is provided on the rotating frame and generates a DC high voltage from the output of the inverter 31. Specifically, the high-voltage generator 32 has an electric circuit such as a transformer and a rectifier, and has a function of generating the high voltage applied to the X-ray tube 33.

[0028] The X-ray tube 33 generates X-rays by the DC high voltage generated by the high-voltage generator 32. Specifically, the X-ray tube 33 is a vacuum tube that generates X-rays by irradiating thermoelectrons from the cathode (filament) to the anode (target) by applying the high voltage from the high-voltage generator 32. For example, there is a rotating anode type X-ray tube that generates X-rays by irradiating thermoelectrons to the rotating anode. Note that the inverter 31, the high-voltage generator 32, and the X-ray tube 33 constitute the X-ray generation system that requires the most power within the CT gantry 27.

[0029] The DC-DC converter 41 converts the DC voltage supplied from the slip ring 30 into a DC voltage suitable for the in-gantry equipment 42.

[0030] The CT gantry internal device 42 is a device mounted on the rotating frame within the CT gantry 27 and operates on the DC voltage converted by the DC-DC converter 41. Examples of the CT gantry internal device 42 include an X-ray detector and a DAS.

[0031] The X-ray detector detects the X-rays irradiated from the X-ray tube 33 and passed through the subject, and outputs an electrical signal corresponding to the X-ray dose to the DAS. The X-ray detector has, for example, a plurality of X-ray detector element arrays in which a plurality of X-ray detector elements are arranged in the channel direction along an arc centered on the focal point of the X-ray tube 33. The X-ray detector has, for example, a structure in which a plurality of X-ray detector element arrays in which a plurality of X-ray detector elements are arranged in the channel direction are arranged in the slice direction (column direction, row direction). Note that the X-ray detector is, for example, an indirect conversion type detector having a grid, a scintillator array, and a photosensor array. The scintillator array has a plurality of scintillators, and each scintillator has a scintillator crystal that outputs light of a photon amount corresponding to the incident X-ray dose. The grid is disposed on the X-ray incident side surface of the scintillator array and has an X-ray shielding plate having a function of absorbing scattered X-rays. Note that the grid may also be called a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array has a function of converting into an electrical signal according to the amount of light from the scintillator, and has, for example, a photosensor such as a photomultiplier (PMT). However, the X-ray detector may be a direct conversion type detector having a semiconductor element that converts the incident X-ray into an electrical signal.

[0032] The DAS has an amplifier that performs amplification processing on the electrical signals output from each X-ray detection element of the X-ray detector, and an A / D converter that converts the electrical signals into digital signals, and generates detection data. The detection data generated by the DAS is output from the rotating frame to the stationary frame via the communication circuit, and transferred to the console device belonging to the CT stationary unit device 52. Here, as the communication circuit between the rotating frame and the stationary frame, for example, as a non-contact communication method, an optical communication circuit equipped with a light-emitting diode (LED) and a photodiode may be mounted. In this case, the detection data generated by the DAS is transmitted by optical communication from a transmitter having a light-emitting diode (LED) provided in the rotating frame to a receiver having a photodiode provided in the stationary frame of the CT gantry 27, and further transferred from the CT gantry 27 to the console device by the transmitter. In addition to this, as the communication method of the communication circuit, in addition to non-contact data transmission such as capacitive coupling type and radio wave type, a contact type data transmission method using a slip ring and an electrode brush may be adopted.

[0033] The converter 51 converts the DC output of the converter 13 into an AC voltage and a DC voltage suitable for the CT stationary unit device 52, respectively.

[0034] The CT stationary unit device 52 is a stationary unit device of the X-ray CT apparatus that does not rotate, and operates with the AC voltage and DC voltage converted by the converter 51. Examples of the CT stationary unit device 52 include a bed device including a top plate and a console device including a monitor.

[0035] The bed device is a device for placing and moving the subject to be scanned, and includes a base, a bed drive device, a top plate, and a support frame. The base is a housing that supports the support frame so as to be movable in the vertical direction. The bed drive device is a motor or actuator that moves the top plate on which the subject is placed in the longitudinal direction of the top plate. The top plate provided on the upper surface of the support frame is a plate on which the subject is placed. Note that the bed drive device may move the support frame in the longitudinal direction of the top plate in addition to the top plate.

[0036] The console device includes a memory, a display (monitor in the figure), an input interface, and a processing circuit (processor). The memory is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory), a flash memory, a hard disk, an optical disk, etc. The memory stores, for example, projection data and reconstructed image data. The monitor displays various kinds of information. For example, the display outputs a medical image (CT image) generated by the processing circuit, a GUI (Graphical User Interface) for receiving various operations from the operator, etc. For example, the display is a liquid crystal display or a CRT (Cathode Ray Tube) display. The input interface receives various input operations from the operator, converts the received input operations into electrical signals, and outputs them to the processing circuit. For example, the input interface receives from the operator collection conditions when collecting projection data, reconstruction conditions when reconstructing a CT image, image processing conditions when generating a post-processed image from a CT image, etc. For example, the input interface is realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, etc. The processing circuit (processor) controls the operation of the X-ray CT device among the X-ray CT mobile examination vehicle 100. For example, the processing circuit executes a system control function, an image generation function, a scan control function, a display control function, etc. The system control function controls various functions of the processing circuit based on the input operations received from the operator via the input interface. The image generation function generates data obtained by performing pre-processing such as logarithmic conversion processing, offset correction processing, sensitivity correction processing between channels, and beam hardening correction on the detection data output from the DAS. Note that the data before pre-processing (detection data) and the data after pre-processing may also be collectively referred to as projection data. Further, the image generation function performs a reconstruction process using a filter correction backprojection method, a successive approximation reconstruction method, etc. on the data subjected to the pre-processing to generate CT image data. Also, the image generation function converts the generated CT image data into tomographic image data of an arbitrary cross-section or three-dimensional image data by a known method based on the input operations received from the operator via the input interface.The scan control function controls the positioning scan and the main scan. During the positioning scan, the scan control function acquires two-dimensional positioning image data of the subject for determining the scan range, imaging conditions, etc. Note that the positioning image data may also be referred to as scanogram image data or scout image data. Also, during the main scan, the scan control function collects detection data for the entire circumference of the subject by helical scan or non-helical scan based on the scan range, imaging conditions, etc. determined by the positioning scan. The collected detection data is used by the image generation function to generate CT image data. The display control function causes various types of information such as medical images and GUI to be displayed on the display.

[0037] Next, the operation of the mobile X-ray CT examination vehicle configured as described above will be described with reference to FIG. 1. Note that the following description is divided into (1) the operation during vehicle travel and (2) the operation during CT examination. Also, the following description mainly describes the flow of electric energy and rotational driving force. That is, descriptions of general operations such as the driving operation of the electric vehicle, the positioning scan of the X-ray CT, and image generation are omitted. (1) Operation during vehicle travel In the mobile X-ray CT examination vehicle 100, during vehicle travel, mainly on the left side of FIG. 1, a power supply system including a hydrogen tank 1, a fuel cell 2, a power storage unit 12, and a power control unit 15, and a drive system including a motor 5, a drive transmission (transmission) mechanism 6, and wheels 7 operate. Here, as shown in the figure, the power control unit 15 of the power supply system includes a boost converter 3, a converter 13, and an inverter 4. Also, the power supply system operates during the CT examination described later. Hereinafter, the operation during vehicle travel will be specifically described.

[0038] In the mobile X-ray CT examination vehicle 100, it is assumed that the hydrogen tank 1 stores hydrogen and the power storage unit 12 stores electric energy. Here, it is assumed that the mobile X-ray CT examination vehicle 100 starts vehicle travel.

[0039] In the X-ray CT mobile examination vehicle 100, when the vehicle is running, the fuel cell 2 converts the hydrogen stored in the hydrogen tank 1 into electrical energy and outputs a DC voltage to the boost converter 3.

[0040] The boost converter 3 boosts the DC voltage output from the fuel cell 2 and supplies it to the converter 13.

[0041] The converter 13 controls the charging and discharging of the power storage unit 12, converts the DC voltage received from the boost converter 3 and / or the power storage unit 12 into an appropriate DC voltage, and outputs it to the inverter 4.

[0042] The inverter 4 converts the output DC voltage into an AC voltage and outputs the obtained AC voltage to the motor 5.

[0043] The motor 5 is rotationally controlled by the AC output of the inverter 4 and outputs a rotational driving force to the drive transmission (speed change) mechanism 6. When the drive transmission (speed change) mechanism 6 is omitted, the motor 5 outputs a rotational driving force to the wheel 7.

[0044] The wheel 7 rotates by the rotational driving force of the motor 5. Thereby, the X-ray CT mobile examination vehicle 100 runs on the road.

[0045] The above is the basic energy consumption operation when the vehicle is running. In addition to this, when decelerating (during decelerated running) while the vehicle is running, the X-ray CT mobile examination vehicle 100 performs a regenerative operation to recover energy. That is, during deceleration, the rotational driving force from the wheel 7 rotates the motor 5 via the drive transmission (speed change) mechanism 6, and the motor 5 becomes a generator and outputs regenerative power to the inverter 4. The regenerative power is converted into DC by the inverter 4 and supplied to the converter 13. The converter 13 charges the power storage unit 12 with the electrical energy (regenerative energy) of the supplied regenerative power. (2) Operation during CT examination In the X-ray CT mobile examination vehicle 100, during CT examination, each element other than the wheel 7 in FIG. 1 operates. Hereinafter, the operation during CT examination will be specifically described.

[0046] In the mobile X-ray CT examination vehicle 100, it is assumed that the hydrogen tank 1 stores hydrogen and the power storage unit 12 stores electrical energy. Here, it is assumed that the X-ray CT examination starts.

[0047] In the mobile X-ray CT examination vehicle 100, during the CT examination, the fuel cell 2 converts the hydrogen stored in the hydrogen tank 1 into electrical energy and outputs a DC voltage to the boost converter 3.

[0048] The boost converter 3 boosts the DC voltage output from the fuel cell 2 and supplies it to the converter 13.

[0049] The converter 13 controls the charging and discharging of the power storage unit 12, converts the DC voltage received from the boost converter 3 and / or the power storage unit 12 into an appropriate DC voltage, and outputs it to the inverter 4, the slip ring 30, and the converter 51.

[0050] The converter 51 converts the DC output of the converter 13 into an AC voltage and a DC voltage suitable for the CT fixed unit device 52, respectively, and supplies them to the CT fixed unit device 52.

[0051] In the CT fixed unit device 52, the bed device and the console device operate by the supplied AC voltage and DC voltage. The console device controls the operation of the X-ray CT device according to the operation of the operator. The bed device is controlled by the console device and moves the top plate on which the subject is placed into the opening surrounded by the rotating frame of the CT gantry 27.

[0052] On the other hand, the inverter 4 converts the DC voltage output from the converter 13 into an AC voltage and outputs the obtained AC voltage to the motor 5.

[0053] The motor 5 is rotationally controlled by the AC output of the inverter 4, and outputs the rotational driving force to the drive transmission (speed change) mechanism 26 of the X-ray CT apparatus via the drive transmission (speed change) mechanism 6. When the drive transmission (speed change) mechanism 6 is omitted, the motor 5 outputs the rotational driving force to the drive transmission (speed change) mechanism 26 of the X-ray CT apparatus.

[0054] The drive transmission (speed change) mechanism 26 transmits the rotational driving force of the motor 5 to the CT gantry 27.

[0055] In the CT gantry 27, the rotating frame supported by the fixed frame rotates by the transmitted rotational driving force. The rotating frame in the CT gantry 27 supports the X-ray tube 33 and the X-ray detector arranged opposite to each other, and further supports the inverter 31, the high-voltage generator 32, and the DAS.

[0056] On the other hand, the DC voltage output from the converter 13 is supplied to the elements in the rotating frame via the slip ring 30. That is, in the rotating frame, the DC voltage is supplied to the inverter 31 of the X-ray generation system that requires the most power and the DC-DC converter 41 of other systems via the slip ring 30.

[0057] The inverter 31 converts the DC voltage supplied from the slip ring 30 and outputs the obtained AC voltage to the high-voltage generator 32.

[0058] The high-voltage generator 32 generates a DC high voltage from the output of the inverter 31 and applies the high voltage to the X-ray tube 33.

[0059] The X-ray tube 33 irradiates X-rays by the applied high voltage.

[0060] On the other hand, the DC-DC converter 41 converts the DC voltage supplied from the slip ring 30 into a DC voltage suitable for the equipment 42 inside the CT gantry.

[0061] The X-ray detector and the DAS, etc., which are the equipment 42 inside the CT gantry, operate by the converted DC voltage.

[0062] The X-ray detector detects the X-rays irradiated from the X-ray tube 33, which have passed through the subject, and outputs an electrical signal corresponding to the X-ray dose to the DAS.

[0063] The DAS generates detection data based on the output of the X-ray detector. The generated detection data is output from the rotating frame to the fixed frame via a non-contact communication circuit, and is transferred to the console device belonging to the CT fixed unit device 52.

[0064] The console device generates CT image data based on the transferred detection data, and displays a CT image on the display based on the CT image data. The displayed CT image is read by a doctor. Alternatively, for later reading, the console device stores the generated CT image data in the memory.

[0065] The above is the basis of the energy consumption operation during CT diagnosis. In addition to this, during deceleration (during decelerated rotation) during CT diagnosis, the X-ray CT mobile diagnostic vehicle 100 performs a regenerative operation to recover energy. That is, during deceleration, the rotational driving force from the rotating frame of the CT gantry 27 rotates the motor 5 via the drive transmission (speed change) mechanism 26, 6, and the motor 5 becomes a generator and outputs regenerative power to the inverter 4. The regenerative power is converted to direct current by the inverter 4 and supplied to the converter 13. The converter 13 charges the storage unit 12 with the electrical energy (regenerative energy) of the supplied regenerative power.

[0066] As described above according to the first embodiment, the storage unit 12 stores electrical energy, and the converter 13 controls the charging and discharging of the storage unit 12. Here, the wheel 7 rotates based on the output from the converter 13. Also, the rotating frame of the CT gantry 27 as the CT rotating unit rotates based on the output from the converter 13.

[0067] Therefore, by adopting a configuration in which the power storage unit 12 and the converter 13 are shared between the time when the vehicle is running with the wheels rotating and the time when the CT rotating unit is rotating during CT examination, the volume and weight of the components mounted on the mobile X-ray CT examination vehicle can be reduced.

[0068] For example, in the case of the mobile X-ray CT examination vehicle 90 according to the comparative example as shown in FIG. 2, an X-ray CT device 92 is mounted on a fuel cell vehicle (FCV) 91.

[0069] Here, the fuel cell vehicle (FCV) 91 includes a power supply system composed of a hydrogen tank 1, a fuel cell 2, a power storage unit 12, and a power control unit 15, and a drive system composed of a motor 5, a drive transmission (transmission) mechanism 6, and wheels 7, as described above.

[0070] Further, different from the above-described configuration, in the X-ray CT device 92, an AC voltage from the AC power supply 21 is supplied to the motor 25 via the inverter 24, and the rotational driving force of the motor 25 rotates the rotating frame of the CT gantry 27 via the drive transmission (transmission) mechanism 26. Different from the above-described configuration, the X-ray CT device 92 has an AC / DC converter 22 between the slip ring 30 and the inverter 31, and an AC / DC converter 23 between the slip ring 30 and the DC / DC converter 41. Further, different from the above-described configuration, the X-ray CT device 92 includes a converter 53 that converts the AC voltage from the AC power supply 21 into an AC voltage and a DC voltage suitable for the CT fixed unit device 52 and supplies them to the CT fixed unit device 52.

[0071] However, in the mobile X-ray CT examination vehicle according to the comparative example, since there is no mechanism (power supply system, drive system) shared between the fuel cell vehicle (FCV) 91 and the X-ray CT device 92, the effects of the first embodiment cannot be obtained.

[0072] In addition, as shown in

[0061] and Fig. 13(a), the medical vehicle (500) according to Patent Document 1 shares a hydrogen storage tank (75) and a fuel cell (73) between the vehicle and the CT. However, in the medical vehicle (500) according to Patent Document 1, the output destinations of the fuel cell (73) are not shared and are branched into the vehicle drive motor (77) and the gantry (7).

[0073] On the other hand, according to the first embodiment, in addition to the power storage unit 12 as an energy source, by adopting a configuration in which a converter 13, which is a hardware resource for adjusting power, is shared, it is excellent in that the volume and weight of the mounted items are further reduced compared to the medical vehicle according to Patent Document 1. In addition, according to the first embodiment, as the number of shared elements increases, such as a configuration in which an inverter 4, a motor 5, and a drive transmission (speed change) mechanism 26 are also shared as described later in addition to the converter 13, a more excellent effect can be achieved.

[0074] Moreover, according to the first embodiment, as described above, since a part of the mechanism as an automobile and a part of the mechanism as an X-ray CT device are shared, the volume and weight of the shared part can be reduced, and the energy utilization efficiency of the entire examination vehicle can be improved. In addition, with a configuration that uses electrical energy not relying on an internal combustion engine, no exhaust gas is generated during both automobile driving and CT examination. Also, since the energy utilization efficiency can be improved and no exhaust gas is generated, the environmental load can be reduced.

[0075] Furthermore, according to the first embodiment, an inverter 4 that converts the DC output of the converter 13 into AC may be further provided. Here, the wheel 7 may rotate based on the output from the inverter 4, and the rotating frame of the CT gantry 27 as the CT rotating unit may also rotate based on the output from the inverter 4. In this case, in addition to the above-described configuration, by adopting a configuration in which the inverter 4 is further shared between automobile driving and CT examination, the above-described effects can be further improved.

[0076] Further, according to the first embodiment, the vehicle may further include a motor 5 whose rotation is controlled by an inverter 4. Here, the wheel 7 may rotate based on the output from the motor 5, and the rotating frame of the CT gantry 27 as the CT rotating unit may rotate based on the output from the motor 5. In this case, in addition to the above-described configuration, by further sharing the motor 5 between when the vehicle is running and when CT examination is performed, the above-described effects can be further improved. Further, according to the first embodiment, the inverter 4, the motor 5, and the wheel 7 may be provided for each driving wheel. In this case, an in-wheel motor configured such that each inverter 4 individually controls the rotation of the motor 5 and each motor 5 individually rotates the wheel 7 can be implemented, and the above-described effects can be obtained in the same manner.

[0077] Further, according to the first embodiment, the vehicle may further include a hydrogen tank 1 for storing hydrogen, a fuel cell 2 for converting the hydrogen in the hydrogen tank 1 into electric energy, and a boost converter 3 for boosting the voltage of the fuel cell 2. Here, the converter 13 may perform an output based on the output of the power storage unit 12 and the output from the boost converter 3. In this case, in a fuel cell vehicle (FCV) including the hydrogen tank 1, the fuel cell 2, and the boost converter 3, the above-described operational effects can be obtained.

[0078] <Second Embodiment> FIG. 3 is a block diagram showing an example of the configuration of an X-ray CT mobile examination vehicle according to the second embodiment. The second embodiment is a modification of the drive system of the first embodiment. Instead of the configuration in which the motor 5 is shared, the motor 5 is specialized for driving the rotation of the wheel 7, and for driving the rotation of the CT gantry 27, a new motor 25 is provided.

[0079] That is, the X-ray CT mobile examination vehicle 100 includes motors 5 and 25 whose rotation is controlled by an inverter 4 in the above-described configuration. Here, the motor 5 is an example of a first motor. The motor 25 is an example of a second motor.

[0080] The wheel 7 rotates based on the output from the motor 5 which is the first motor. In the example shown in FIG. 3, the wheel 7 rotates by the rotational driving force of the motor 5 transmitted from the drive transmission (speed change) mechanism 6. However, it is not limited to this. For example, when the wheel 7 and the motor 5 are provided for each driving wheel as the in-wheel motor described above, the drive transmission (speed change) mechanism 6 is omitted.

[0081] The rotating frame of the CT gantry 27 rotates based on the output from the motor 25 which is the second motor. The motor 25 may be provided either integrally with or separately from the CT gantry 27. When the motor 25 is integral with the CT gantry 27, the drive transmission (speed change) mechanism 26 can be omitted.

[0082] Other configurations are the same as those in the first embodiment.

[0083] Next, the operation of the X-ray CT mobile examination vehicle configured as described above will be described with reference to FIG. 3. The following description will be divided into (1) the operation during automobile travel and (2) the operation during CT examination, as described above.

[0084] (1) The operation during automobile travel is the same as that in the first embodiment.

[0085] (2) The operation during CT examination is the same as that in the first embodiment, except that the motor 25 is interposed between the inverter 4 and the drive transmission (speed change) mechanism 26.

[0086] That is, in the operation during CT examination, as described above, the converter 13 controls the charging and discharging to the power storage unit 12, and converts the DC voltage received from the boost converter 3 and / or the power storage unit 12 into an appropriate DC voltage and outputs it to the inverter 4, the slip ring 30, and the converter 51.

[0087] The converter 51 and the CT fixed unit device 52 operate as described above.

[0088] On the one hand, the inverter 4 converts the DC voltage output from the converter 13 into an AC voltage and outputs the obtained AC voltage to the motor 25.

[0089] The motor 25 is rotationally controlled by the AC output of the inverter 4 and outputs a rotational driving force to the drive transmission (speed change) mechanism 26 of the X-ray CT apparatus. When the drive transmission (speed change) mechanism 26 is omitted, the motor 25 transmits the rotational driving force to the CT gantry 27.

[0090] The drive transmission (speed change) mechanism 26 transmits the rotational driving force of the motor 25 to the CT gantry 27.

[0091] The CT gantry 27 has a rotating frame supported by a fixed frame, which rotates by the transmitted rotational driving force. Hereinafter, in the same manner as described above, each element in the CT gantry 27 and the console device operate to perform CT diagnosis.

[0092] Also, during deceleration (decelerated rotation) during CT examination, the rotational driving force from the rotating frame of the CT gantry 27 rotates the motor 25 via the drive transmission (speed change) mechanism 26, and the motor 25 becomes a generator and outputs regenerative power to the inverter 4. Similarly hereinafter, the regenerative power is charged to the power storage unit 12 as regenerative energy via the inverter 4 and the converter 13.

[0093] As described above, according to the second embodiment, the motor 5 (first motor) and the motor 25 (second motor) rotationally controlled by the inverter 4 are provided. The wheel 7 rotates based on the output from the motor 5. The CT gantry 27 (CT rotating unit) rotates based on the output from the motor 25.

[0094] Therefore, according to the second embodiment, among the effects of the first embodiment, the effects excluding the effect when the motor is shared can be obtained. For example, according to the second embodiment, by sharing the power storage unit 12 and the converter 13 between when the vehicle is running with the wheels rotating and when CT examination is performed with the CT rotating unit rotating, the volume and weight of the components mounted on the mobile X-ray CT examination vehicle can be reduced. Also, for example, according to the second embodiment, with a configuration in which the inverter 4 is further shared, the above-described effects can be further improved. Also, for example, according to the second embodiment, in a fuel cell vehicle (FCV) equipped with a hydrogen tank 1, a fuel cell 2, and a boost converter 3, the above-described effects can be obtained.

[0095] Note that the second embodiment may be implemented as the following first modification example or second modification example.

[0096] As shown in FIG. 4, the first modification example of the second embodiment further includes a switching mechanism 8 that switches the electrical connection between the inverter 4 and the motor 5 or the motor 25.

[0097] Here, the switching mechanism 8 electrically connects the inverter 4 and the motor 5 when moving the mobile X-ray CT examination vehicle 100. Also, the switching mechanism 8 electrically connects the inverter 4 and the motor 25 when performing a CT examination with the mobile X-ray CT examination vehicle 100. Note that the switching mechanism 8 is an example of a switching unit.

[0098] According to such a first modification example, by providing a switching mechanism 8 that switches the connection between the inverter 4 and the motor 5 or the motor 25 between when the vehicle is running and when CT examination is performed, the same effects as the second embodiment can be obtained.

[0099] On the other hand, as shown in FIG. 5, the second modification example of the second embodiment includes an inverter 4-1 connected to the motor 5 for vehicle running and an inverter 4-2 connected to the motor 25 for CT examination, as described above.

[0100] Here, when the inverter 4-1 moves the X-ray CT mobile examination vehicle 100, it converts the DC output of the converter 13 into AC. By this inverter 4-1, the motor 5, which is the first motor, is rotationally controlled. Also, the inverter 4-1 is controlled to be in the off state during CT examination. Note that the inverter 4-1 is an example of the first inverter.

[0101] When the X-ray CT mobile examination vehicle 100 performs a CT examination, the inverter 4-2 converts the DC output of the converter 13 into AC. By this inverter 4-2, the motor 25, which is the second motor, is rotationally controlled. Also, the inverter 4-2 is controlled to be in the off state during automobile driving. Note that the inverter 4-2 is an example of the second inverter.

[0102] According to such a second modification, it includes the inverter 4-1 that rotationally controls the motor 5 during automobile driving and the inverter 4-2 that rotationally controls the motor 25 during CT examination. Therefore, according to the second modification, among the effects of the second embodiment, the effects excluding the effect when the inverter is shared can be obtained.

[0103] <The Third Embodiment> FIG. 6 is a block diagram showing an example of the configuration of an X-ray CT mobile examination vehicle according to the third embodiment. The third embodiment is a modification in the power supply system of the first embodiment. Instead of a fuel cell vehicle (FCV) having a hydrogen tank 1, a fuel cell 2, etc., an electric vehicle (EV) equipped with a charging mechanism 11 for charging electrical energy into the power storage unit 12 is used.

[0104] Specifically, the X-ray CT mobile examination vehicle 100 shown in FIG. 6 omits the hydrogen tank 1, the fuel cell 2, and the boost converter 3 compared to the configuration shown in FIG. 1, and further includes a charging mechanism 11.

[0105] The charging mechanism 11 charges the power storage unit 12 from an external power source. Here, as the external power source, for example, it may be a normal charging facility that supplies AC power, or it may be a rapid charging facility that supplies a large DC current. Accordingly, the charging mechanism 11 may include, for example, a first charging port and a second charging port that can be electrically connected to the external power source. That is, when the external power source is a normal charging facility, the charging mechanism 11 converts the output of the external power source received from the first charging port and charges the power storage unit 12 with DC electrical energy. When the external power source is a rapid charging facility, the charging mechanism 11 charges the power storage unit 12 with the output of the external power source received from the second charging port. The charging by this charging mechanism 11 is performed, for example, at a time other than when the vehicle is running. Note that the charging mechanism 11 is an example of a charging unit.

[0106] Other configurations are the same as those in the first embodiment.

[0107] According to the third embodiment as described above, instead of the hydrogen tank 1, the fuel cell 2, and the boost converter 3, a configuration including the charging mechanism 11 can achieve miniaturization and weight reduction of the power supply system in addition to the effects of the first embodiment.

[0108] <Fourth Embodiment> FIG. 7 is a block diagram showing an example of the configuration of an X-ray CT mobile examination vehicle according to the fourth embodiment. The fourth embodiment is a modification of the power supply system in the second embodiment. Instead of a fuel cell vehicle (FCV) having a hydrogen tank 1, a fuel cell 2, etc., an electric vehicle (EV) equipped with a charging mechanism 11 that charges electrical energy into the power storage unit 12 is used.

[0109] Specifically, the X-ray CT mobile examination vehicle 100 shown in FIG. 7 omits the hydrogen tank 1, the fuel cell 2, and the boost converter 3 compared to the configuration shown in FIG. 3, and further includes a charging mechanism 11.

[0110] The charging mechanism 11 charges the power storage unit 12 from an external power source. Examples of the charging mechanism 11 and the external power source are the same as those in the third embodiment. The charging by this charging mechanism 11 is performed, for example, at a time other than when the vehicle is running. Note that the charging mechanism 11 is an example of a charging unit.

[0111] Other configurations are the same as those in the second embodiment.

[0112] According to the fourth embodiment as described above, instead of the hydrogen tank 1, the fuel cell 2, and the boost converter 3, with a configuration including the charging mechanism 11, in addition to the effects of the second embodiment, miniaturization and weight reduction of the power supply system can be achieved.

[0113] Note that the fourth embodiment may be applied to the first modification example and the second modification example of the second embodiment. In this case, according to the fourth embodiment, the same effects as those of the applied first modification example or second modification example can be obtained.

[0114] According to at least one of the embodiments described above, the volume and weight of the objects mounted on the mobile X-ray CT examination vehicle can be reduced.

[0115] As used in the above description, the term "processor" means, for example, a CPU (central processing unit), a GPU (Graphics Processing Unit), or an application specific integrated circuit (ASIC), a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA), etc.). The processor realizes its functions by reading and executing the programs stored in the memory. Note that instead of storing the programs in the memory, the programs may be directly incorporated into the circuit of the processor. In this case, the processor realizes its functions by reading and executing the programs incorporated into the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, and a plurality of independent circuits may be combined to be configured as one processor to realize its functions. Further, a plurality of components in each of FIGS. 1 and 3 to 7 may be integrated into one processor to realize its functions.

[0116] Although some embodiments of the present invention have been described, these embodiments are presented as examples 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 gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

Description of Reference Numerals

[0117] 1 Hydrogen tank 2 Fuel cell 3 Boost converter 4,4-1,4-2,31 Inverter 5 Motor 6,26 Drive transmission (speed change) mechanism 7 Wheel 8 Switching mechanism 11 Charging mechanism 12 Energy storage unit 13,51 Converter 27 CT gantry 30 Slip ring 32 High voltage generator 33 X-ray tube 41 DC-DC converter 42 Equipment inside CT gantry 52 Equipment for CT fixing part 100 Mobile X-ray CT examination vehicle

Claims

1. A power storage unit that stores electrical energy, a converter that controls charging and discharging of the power storage unit, a wheel that rotates based on the output from the converter, a CT rotating unit that rotates based on the output from the converter, an X-ray CT mobile examination vehicle comprising: an inverter that converts the DC output of the converter into AC, a first motor and a second motor whose rotation is controlled by the inverter, a switching unit that switches the electrical connection between the inverter and the first motor or the second motor, further comprising: the wheel rotates based on the output from the first motor, the CT rotating unit rotates based on the output from the second motor, the switching unit: electrically connects the inverter and the first motor when moving the X-ray CT mobile examination vehicle, electrically connects the inverter and the second motor when performing a CT examination with the X-ray CT mobile examination vehicle. An X-ray CT mobile examination vehicle.

2. A power storage unit that stores electrical energy, a converter that controls charging and discharging of the power storage unit, a wheel that rotates based on the output from the converter, a CT rotating unit that rotates based on the output from the converter, an inverter that converts the DC output of the converter into AC, a motor whose rotation is controlled by the inverter, a first drive transmission mechanism that transmits the rotational driving force output from the motor, a second drive transmission mechanism that transmits the rotational driving force transmitted from the first drive transmission mechanism, comprising: the wheel rotates by the rotational driving force transmitted from the first drive transmission mechanism, the CT rotating unit rotates by the rotational driving force transmitted from the second drive transmission mechanism. An X-ray CT mobile examination vehicle.

3. a hydrogen tank that stores hydrogen, a fuel cell that converts the hydrogen in the hydrogen tank into electrical energy, a boost converter that boosts the voltage of the fuel cell, further comprising: the converter performs an output based on the output of the power storage unit and the output from the boost converter. The X-ray CT mobile examination vehicle according to Claim 1 or 2.

4. The X-ray CT mobile examination vehicle according to Claim 1 or 2, further comprising a charging unit that charges the power storage unit from an external power source.

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