Medical image diagnostic device, medical image diagnostic method, and program

Abstract

To measure the weight of an analyte riding on a bed with a simple constitution.SOLUTION: A medical image diagnostic apparatus according to an embodiment comprises an acquisition part and a derivation part. The acquisition part acquires torque generated when a driving source which drives a bed on which an analyte being a target of image diagnosis rides starts driving the bed. The derivation part derives the weight of the analyte based on the torque acquired by the acquisition part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The embodiments disclosed in the present specification and drawings relate to a medical image diagnostic apparatus, a medical image diagnostic method, and a program. [Background technology]

[0002] In diagnoses using medical imaging diagnostic devices such as X-ray CT (Computed Tomography) devices, administering a contrast agent to a subject such as a patient makes it possible to image detailed areas inside the body. The amount of contrast agent administered to the subject is calculated based on, for example, the weight (body weight) of the subject. Therefore, it is necessary to know the weight of the subject in advance.

[0003] When measuring the weight of a subject, if the subject cannot stand on their own, it is difficult to take an image quickly and the number of steps required for diagnosis increases. The weight can also be determined by the subject's own report, but in this case, if the weight is underreported, it becomes difficult to determine the accurate amount of contrast agent.

[0004] Therefore, there is a technology to measure the weight of a subject by measuring the load applied to the bed when the subject sits on the bed of a medical image diagnostic equipment. This technology uses sensors such as load cells to detect weight on the support device that supports the bed. This may result in an increase in the number of parts in the medical image diagnostic equipment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-125305 [Patent Document 2] Japanese Patent Application Publication No. 3-70548 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-167189 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the embodiments disclosed in this specification and the drawings is to be able to measure the weight of a subject placed on a bed using a simple configuration. However, the problem to be solved by the embodiments disclosed in this specification and the drawings is not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0007] According to an embodiment, a medical image diagnostic apparatus includes an acquisition unit and a derivation unit. The acquisition unit acquires torque when a drive source for driving a bed on which a subject to be imaged sits starts driving the bed. The derivation unit derives a weight of the subject based on the torque acquired by the acquisition unit. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram of an X-ray CT apparatus 1 according to an embodiment. [Figure 2] FIG. [Figure 3] 10 is a flowchart showing an example of processing executed when capturing a contrast CT image. [Figure 4] 10 is a flowchart showing an example of a process for deriving a derived weight. [Figure 5] FIG. 4 is a block diagram showing the flow of electrical signals when deriving a derived weight. [Figure 6A] 6 is a graph showing the change over time in the value of the current flowing through the motor 70. [Figure 6B] 10 is a graph showing the change over time in the lifting speed of the top plate 33 in response to the change over time in the current flowing through the motor 70. [Figure 7] FIG. 10 is a diagram showing an overview of an example of a tabletop vertical movement model M. [Figure 8] FIG. 2 is a diagram showing an overview of a first parallel link mechanism 80. [Figure 9] FIG. 4 is a diagram showing an overview of a second parallel link mechanism 90. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a medical image diagnostic apparatus, a medical image diagnostic method, and a program according to an embodiment will be described with reference to the drawings.

[0010] (First embodiment) FIG. 1 is a configuration diagram of an X-ray CT apparatus 1 according to an embodiment. The X-ray CT apparatus 1 includes, for example, a gantry 10, a camera 20, a bed 30, and a console 40. For convenience of explanation, FIG. 1 shows both a view of the gantry 10 from the Z-axis direction and a view of the gantry 10 from the X-axis direction. However, in reality, there is only one gantry 10. In this embodiment, the rotation axis of the rotating frame 17 in a non-tilted state or the longitudinal direction of the tabletop 33 of the bed 30 is defined as the Z-axis direction, an axis perpendicular to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction, and a direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. The X-ray CT apparatus 1 captures contrast-enhanced CT images for image diagnosis. The X-ray CT apparatus 1 is an example of a medical image diagnostic apparatus.

[0011] The gantry device 10 includes, for example, an X-ray tube 11, a wedge 12, a collimator 13, an X-ray high voltage device 14, an X-ray detector 15, a data acquisition system (hereinafter referred to as DAS: Data Acquisition System) 16, a rotating frame 17, and a control device 18.

[0012] The X-ray tube 11 generates X-rays by irradiating thermoelectrons from a cathode (filament) to an anode (target) when a high voltage is applied from the X-ray high voltage device 14. The X-ray tube 11 includes a vacuum tube. For example, the X-ray tube 11 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

[0013] The wedge 12 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11 to the subject P who is the subject of image diagnosis. The wedge 12 attenuates the X-rays that pass through it so that the distribution of the X-ray dose irradiated from the X-ray tube 11 to the subject P becomes a predetermined distribution. The wedge 12 is also called a wedge filter or a bow-tie filter. The wedge 12 is made by processing aluminum to have, for example, a predetermined target angle and a predetermined thickness.

[0014] The collimator 13 is a mechanism for narrowing the irradiation range of the X-rays that have passed through the wedge 12. The collimator 13 narrows the irradiation range of the X-rays, for example, by forming a slit using a combination of multiple lead plates. The collimator 13 is sometimes called an X-ray aperture. The narrowing range of the collimator 13 may be mechanically drivable.

[0015] The X-ray high voltage device 14 includes, for example, a high voltage generator and an X-ray control device. The high voltage generator has an electric circuit including a transformer and a rectifier, and generates a high voltage to be applied to the X-ray tube 11. The X-ray control device controls the output voltage of the high voltage generator according to the X-ray dose to be generated by the X-ray tube 11. The high voltage generator may be one that boosts voltage using the above-mentioned transformer, or one that boosts voltage using an inverter. The X-ray high voltage device 14 may be provided on the rotating frame 17, or may be provided on the side of the fixed frame (not shown) of the gantry device 10.

[0016] The X-ray detector 15 detects the intensity of X-rays generated by the X-ray tube 11 and incident upon the subject P. The X-ray detector 15 outputs an electrical signal (which may be an optical signal, etc.) corresponding to the intensity of the detected X-rays to the DAS 16. The X-ray detector 15 has, for example, multiple X-ray detection element rows. Each of the multiple X-ray detection element rows has multiple X-ray detection elements arranged in the channel direction along an arc centered on the focal point of the X-ray tube 11. The multiple X-ray detection element rows are arranged in the slice direction (column direction, row direction).

[0017] The X-ray detector 15 is, for example, an indirect detector having a grid, a scintillator array, and a photosensor array. The scintillator array has multiple scintillators. Each scintillator has scintillator crystals. The scintillator crystals emit light with an amount of light corresponding to the intensity of the incident X-rays. The grid is arranged on the surface of the scintillator array on which the X-rays are incident and has an X-ray shielding plate that has the function of absorbing scattered X-rays. The grid is sometimes called a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array has, for example, a photosensor such as a photomultiplier tube (PMT). The photosensor array outputs an electrical signal corresponding to the amount of light emitted by the scintillator. The X-ray detector 15 may also be a direct conversion detector having a semiconductor element that converts incident X-rays into an electrical signal.

[0018] The DAS 16 includes, for example, an amplifier, an integrator, and an A / D converter. The amplifier amplifies the electrical signals output by each X-ray detection element of the X-ray detector 15. The integrator integrates the amplified electrical signals over a view period. The A / D converter converts the electrical signals indicating the integration results into digital signals. The DAS 16 outputs detection data based on the digital signals to the console device 40.

[0019] The rotating frame 17 supports the X-ray tube 11, wedge 12, collimator 13, and X-ray detector 15 in opposing positions. The rotating frame 17 is an annular member having two circular side surfaces with a circular opening formed in the center, an inner side surface connecting the inner circles on both sides, and an outer side surface connecting the outer circles on both sides. Both side surfaces of the rotating frame 17 are flat, and the inner and outer sides are curved.

[0020] The rotating frame 17 is an annular member that supports the X-ray tube 11, wedge 12, collimator 13, and X-ray detector 15 in opposing positions. The rotating frame 17 is supported by a fixed frame (not shown) so as to be rotatable around the subject P introduced therein. The rotating frame 17 also supports the DAS 16. Detection data output by the DAS 16 is transmitted by optical communication from a transmitter having a light-emitting diode (LED) provided on the rotating frame 17 to a receiver having a photodiode provided on a non-rotating portion of the gantry device 10 (e.g., the fixed frame), and then transferred to the console device 40 by the receiver. Note that the method of transmitting the detection data from the rotating frame 17 to the non-rotating portion is not limited to the above-mentioned method using optical communication, and any non-contact transmission method may be used. The rotating frame 17 is not limited to an annular member, and may be an arm-like member as long as it can support and rotate the X-ray tube 11 and the like.

[0021] The X-ray CT device 1 is, for example, a Rotate / Rotate-Type X-ray CT device (third generation CT) in which both the X-ray tube 11 and the X-ray detector 15 are supported by a rotating frame 17 and rotate around the subject P, but is not limited to this and may also be a Stationary / Rotate-Type X-ray CT device (fourth generation CT) in which multiple X-ray detection elements arranged in a circular ring are fixed to a fixed frame and the X-ray tube 11 rotates around the subject P.

[0022] The control device 18 has, for example, a processing circuit having a processor such as a CPU (Central Processing Unit), and a drive mechanism including a motor, an actuator, etc. The processing circuit realizes these functions by, for example, a hardware processor executing a program stored in a storage device (storage circuit).

[0023] The term "hardware processor" refers to a circuit such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD) or a complex programmable logic device (CPLD)), or a field programmable gate array (FPGA). Instead of storing a program in a memory device, the program may be directly embedded in the circuit of the hardware processor. In this case, the hardware processor realizes its function by reading and executing the program embedded in the circuit. The hardware processor is not limited to being configured as a single circuit, but may be configured as a single hardware processor by combining multiple independent circuits to realize each function. The memory device may be a non-transitory (hardware) storage medium. Furthermore, multiple components may be integrated into a single hardware processor to realize each function.

[0024] The control device 18, for example, rotates the rotating frame 17, tilts the gantry of the gantry device 10, moves the top board 33 of the bed device 30 by vertical movement or the like, and causes the X-ray tube 11 to emit (irradiate) X-rays. The control device 18 may be provided in the gantry device 10 or in the console device 40.

[0025] The camera 20 includes, for example, a first camera 21 and a second camera 22. Both the first camera 21 and the second camera 22 are provided above the tabletop 33 of the bed device 30. Both the first camera 21 and the second camera 22 are provided on the upper and right side of the gantry device 10 on the side where the bed is provided, facing the direction of the bed device 30. The camera 20 captures, for example, an image of an optional item mounted on the tabletop 33. Examples of optional items include a syringe pump, a drainage bag, a urine collection bag, a bedside monitor, a medical oxygen cylinder, a backboard, an infusion solution, and a tray. The camera 20 transmits an electrical signal of an image including the captured optional item to the console device 40. The tabletop 33 is an example of a bed. The optional item is an example of an accessory. The weight of the optional item may be measured each time, or may be previously associated with the optional item and stored in the memory 41.

[0026] The bed device 30 is a device on which the subject P to be scanned is placed, moved, and introduced into the rotating frame 17 of the gantry device 10. The bed device 30 includes, for example, a base 31, a bed vertical movement device 32, a top plate 33, and a support frame 34. The base 31 includes a housing that supports the support frame 34 so that it can move in the vertical direction (Y-axis direction).

[0027] 2 is a perspective view of the bed lifting device 32. The bed lifting device 32 includes, for example, an X-link mechanism 60 and a motor 70. The X-link mechanism 60 includes a first link 61 and a second link 62 pivotally supported in an X shape. The first link 61 and the second link 62 are provided rotatably around a fulcrum 63. The first link 61 and the second link 62 are formed of a pair of plate-shaped metal plates having the same length.

[0028] A first lower link 64 is suspended between the lower ends of the first links 61, and a first upper link 65 is suspended between the upper ends of the first links 61. A second lower link 66 is suspended between the lower ends of the second links 62, and a second upper link 67 is suspended between the upper ends of the second links 62.

[0029] The first lower link 64 is disposed above the base 31 so as to be slidable in the Z direction. The first upper link 65 supports the support frame 34 so as to be slidable in the Z direction. The second lower link 66 is pivotally supported on the base 31 so as to be rotatable on its axis. The second upper link 67 is pivotally supported on the support frame 34 so as to be rotatable on its axis. The tabletop 33 is supported by the support frame 34 so as to be slidable (movable) in the longitudinal direction of the tabletop 33. The tabletop 33 is movable in the vertical direction by transmitting the torque of the motor 70 via the bed vertical movement device 32 having the X link mechanism 60. The bed vertical movement device 32 is an example of a drive force transmission mechanism.

[0030] The motor 70 is mounted on the base 31. One end of a lead screw 71 is connected to the motor 70. When the motor 70 is operated, the lead screw 71 is rotated. A nut 72 is attached to the lead screw 71. The motor 70 rotates the lead screw 71, thereby moving the nut 72. The motor 70 is an example of a drive source.

[0031] For example, the motor 70 rotates the lead screw 71 clockwise about an axis (hereinafter, Z axis) along the Z direction, which is connected to the lower end of the first link 61, thereby moving the nut 72 in a direction away from the motor 70 (+Z direction). As the nut 72 moves in the +Z direction, the lower end of the first link 61 is pushed in the +Z direction, and the upper ends of the first link 61 and the second link 62 rise to the same height. As the upper ends of the first link 61 and the second link 62 rise, the support frame 34 and the top plate 33 (FIG. 1) placed on the support frame 34 rise.

[0032] The motor 70 rotates the lead screw 71 counterclockwise about the X-axis, thereby moving the nut 72 in a direction (-Z direction) approaching the motor 70. When the nut 72 moves in the -Z direction, the weight of the top plate 33 and the subject P placed on the top plate 33 causes the support frame 34 and the top plate 33 placed on the support frame 34 to descend.

[0033] Returning to FIG. 1, a current sensor 75 is attached to the motor 70. The current sensor 75 detects the detected value of the current flowing through the motor 70 when the motor 70 rotates the lead screw 71. The current sensor 75 transmits an electrical signal corresponding to the detected current value to the processing circuit 50 of the console device 40.

[0034] An encoder 78 is attached to the tabletop 33. The encoder 78 detects the amount of vertical displacement of the tabletop 33 from a predetermined reference point. The encoder 78 transmits the detected amount of displacement of the tabletop 33 to the console device 40. The encoder 78 may also detect the amount of vertical or horizontal displacement of the upper end of the slidable first link 61 of the X-link mechanism 60.

[0035] The console device 40 includes, for example, a memory 41, a display 42, an input interface 43, an alarm device 44, and a processing circuit 50. In the embodiment, the console device 40 is described as being separate from the gantry device 10, but the gantry device 10 may include some or all of the components of the console device 40.

[0036] The memory 41 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 41 stores, for example, detection data, projection data, reconstructed image data, CT image data, etc. The memory 41 further stores the weight of optional items assumed to be mounted on the tabletop 33 when capturing a contrast-enhanced CT image, and a simulator used to derive a derived weight, which will be described later. These data may be stored in an external memory with which the X-ray CT apparatus 1 can communicate, instead of (or in addition to) the memory 41. The external memory is controlled by a cloud server that manages the external memory, for example, by the cloud server receiving a read / write request.

[0037] The display 42 displays various types of information. For example, the display 42 displays medical images (CT images) generated by a processing circuit, GUI (Graphical User Interface) images that accept various operations by an operator such as a doctor or technician, and the like. The display 42 is, for example, a liquid crystal display, a CRT (Cathode Ray Tube), an organic EL (Electroluminescence) display, or the like. The display 42 may be provided on the gantry device 10. The display 42 may be a desktop type, or may be a display device (for example, a tablet terminal) that can wirelessly communicate with the main body of the console device 40.

[0038] The input interface 43 accepts various input operations by the operator and outputs an electrical signal indicating the content of the accepted input operation to the processing circuitry 50. For example, the input interface 43 accepts input operations such as acquisition conditions when acquiring detection data or projection data, reconstruction conditions when reconstructing a CT image, and image processing conditions when generating a post-processed image from the CT image.

[0039] The input interface 43 further receives input operations of the subject P, such as the name and weight (body weight) of the subject P, when capturing a contrast CT image of the subject P. The input interface 43 is realized by, for example, a mouse, a keyboard, a touch panel, a drag ball, a switch, a button, a joystick, a camera, an infrared sensor, a microphone, etc. The input interface 43 may also be realized by a display device (for example, a tablet terminal) capable of wireless communication with the main body of the console device 40.

[0040] In this specification, the input interface is not limited to an interface having physical operation parts such as a mouse, keyboard, etc. For example, an example of an input interface also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs this electrical signal to a control circuit.

[0041] The alarm device 44 has a function of displaying an image on the display 42 and a function of outputting an alarm from a buzzer, speaker, etc. When warning information is output by the processing circuitry 50, the alarm device 44 displays a notification on the display 42 to select the weight of the subject P to be used when capturing a contrast CT image. When displaying the notification on the display 42, the alarm device 44 outputs an alarm from a buzzer, speaker, etc. The alarm device 44 warns the operator by displaying on the display 42 or outputting an alarm from a buzzer, speaker, etc.

[0042] The processing circuitry 50 controls the overall operation of the X-ray CT apparatus 1. The processing circuitry 50 includes, for example, a control function 51, a preprocessing function 52, a reconstruction processing function 53, an image processing function 54, an acquisition function 55, a derivation function 56, a determination function 57, a warning function 58, and a calculation function 59. The processing circuitry 50 realizes these functions by, for example, a hardware processor executing a program stored in a storage device (storage circuit).

[0043] A hardware processor refers to a circuit such as a CPU, GPU, application-specific integrated circuit, programmable logic device or composite programmable logic device, or field programmable gate array. Instead of storing a program in a storage device, the program may be directly embedded in the circuit of the hardware processor. A hardware processor is not limited to a single circuit, but may be configured as a single hardware processor by combining multiple independent circuits to realize each function. The storage device may be a non-transitory (hardware) storage medium. Furthermore, multiple components may be integrated into a single hardware processor to realize each function.

[0044] Each component of the console device 40 or the processing circuitry 50 may be distributed and realized by multiple pieces of hardware. The processing circuitry 50 may not be a component of the console device 40, but may be realized by a processing device capable of communicating with the console device 40. The processing device is, for example, a workstation connected to one X-ray CT device, or a device (for example, a cloud server) connected to multiple X-ray CT devices and collectively executing processing equivalent to that of the processing circuitry 50 described below.

[0045] Each function included in the processing circuitry 50 may be distributed among multiple circuits, or may be made available by activating application software stored in the memory 41. For example, the control function 51, preprocessing function 52, reconstruction processing function 53, and image processing function 54 may be included in the processing circuitry 50, and the acquisition function 55, derivation function 56, determination function 57, warning function 58, and calculation function 59 may be made available by activating application software stored in the memory 41.

[0046] The control function 51 controls various functions of the processing circuit 50 based on input operations received by the input interface 43. For example, the control function 51 controls the X-ray high voltage device 14, the DAS 16, the control device 18, and the bed vertical movement device 32 to perform processing such as collection of detection data in the gantry device 10.

[0047] The pre-processing function 52 performs pre-processing such as logarithmic conversion processing, offset correction processing, inter-channel sensitivity correction processing, and beam hardening correction on the detection data output by the DAS 16, generates projection data, and stores the generated projection data in the memory 41.

[0048] The reconstruction processing function 53 performs reconstruction processing using a filtered back projection method, an iterative reconstruction method, or the like on the projection data generated by the preprocessing function 52 to generate CT image data, and stores the generated CT image data in the memory 41.

[0049] The image processing function 54 converts the CT image data into three-dimensional image data or cross-sectional image data of an arbitrary cross section by a known method based on the input operation received by the input interface 43. The conversion into three-dimensional image data may be performed by the pre-processing function 52.

[0050] The acquisition function 55 acquires information about the subject P, such as the name and weight of the subject P, based on an input operation received by the input interface 43. The acquisition function 55 stores the acquired information about the subject P in the memory 41 as registration information. The acquisition function 55 receives and acquires an electrical signal transmitted by the current sensor 75. The acquisition function 55 outputs a detected value of the current based on the received electrical signal to the derivation function 56.

[0051] The acquisition function 55 receives an electrical signal of the image transmitted by the camera 20. The acquisition function 55 acquires information about optional items mounted on the tabletop 33 by image processing the image based on the received electrical signal. The acquisition function 55 acquires information about the weight of the optional items mounted on the tabletop 33 (hereinafter, optional item information) by referring to the information about the optional items mounted on the tabletop 33 with the weight of the optional items stored in the memory 41. The acquisition function 55 outputs the acquired optional item information to the derivation function 56. The acquisition function 55 is an example of an acquisition unit.

[0052] The derivation function 56 calculates the torque of the motor 70, for example, the torque when starting to move the tabletop 33 (hereinafter referred to as initial torque), based on the detected value of the current output by the acquisition function 55. The detected value of the current acquired by the acquisition function 55 and output to the derivation function 56 is an example of torque information related to the initial torque of the tabletop 33. The initial torque is, for example, the torque of the motor 70 based on the detected value of the current at the timing when the displacement amount transmitted by the encoder 78 changes (increases).

[0053] The derivation function 56 receives the displacement amount of the tabletop 33 transmitted by the encoder 78. The derivation function 56 acquires the height position of the tabletop 33 based on the received displacement amount of the tabletop 33. The derivation function 56 calculates the load applied to the tabletop 33 based on both the calculated initial torque and the derived height position of the tabletop 33. The derivation function 56 may calculate the load applied to the tabletop 33 based on a position other than the height position, for example, a position indicated by a relative distance from the motor 70, instead of the height position of the tabletop 33.

[0054] The derivation function 56 derives (measures) the weight of the subject P (hereinafter referred to as the derived weight) by subtracting the weight of the optional item included in the optional item information output by the acquisition function 55 from the calculated load applied to the top board 33. The derivation function 56 outputs information on the derived weight to the determination function 57. The derivation function 56 is an example of a derivation unit.

[0055] When the derivation function 56 outputs information on the derived weight, the determination function 57 reads out the weight of the subject P (hereinafter referred to as the registered weight) included in the registered information stored in the memory 41. The determination function determines whether there is a difference between the derived weight and the registered weight. When the determination function 57 determines that there is no difference between the derived weight, it outputs weight information including either the derived weight or the registered weight to the calculation function 59. When the determination function 57 determines that there is a difference between the derived weight and the registered weight, it outputs weight information on the derived weight and the registered weight to the warning function 58.

[0056] When weight information of the derived weight and registered weight is output by the determination function 57, the warning function 58 outputs warning information to the alarm device 44, causing the alarm device 44 to issue a warning. After the warning is issued by the alarm device 44, the input interface 43 accepts selection information of the derived weight or the registered weight selected by an input operation by the operator. The warning function 58 outputs weight information of either the derived weight or the registered weight according to the selection information accepted by the input interface 43 to the calculation function 59.

[0057] The calculation function 59 calculates the amount of contrast agent to be administered to the subject P based on the weight information output by the determination function 57 or the warning function 58. The calculation function 59 outputs contrast agent information including the calculated amount of contrast agent to the control function 51. The control function 51 uses the contrast agent information output by the calculation function 59 to generate a scan plan for capturing a contrast CT image of the subject P, and performs imaging (scanning) in accordance with the scan plan.

[0058] Next, processing in the X-ray CT apparatus 1 of the first embodiment will be described. Fig. 3 is a flowchart showing an example of processing executed when capturing a contrast-enhanced CT image. In the X-ray CT apparatus 1, when capturing a contrast-enhanced CT image, first, the input interface 43 accepts information about the subject P input by an input operation by the operator (step S101). The information about the subject P includes information such as the name and weight (body weight) of the subject P. The input interface 43 transmits the accepted information to the processing circuitry 50. The acquisition function 55 in the processing circuitry 50 acquires the information about the subject P transmitted by the input interface 43 and registers it in the memory 41 (step S101). The weight of the subject P registered here becomes the registered weight.

[0059] Next, after the information of the subject P is registered, the subject P is placed on the top board 33 of the bed device 30 and fixed as necessary (step S103). Next, the operator operates the motor 70 to operate the bed elevation device 32, and moves the top board 33 up and down to adjust the height according to the physique of the subject P, the type of diagnosis, etc. (step S105).

[0060] When adjusting the height of the tabletop 33, the processing circuitry 50 of the console device 40 measures and derives the weight of the subject P based on the detected value of the current detected by the current sensor 75 (step S107). The procedure by which the processing circuitry 50 measures and derives the weight of the subject P will be explained further later using a separate flowchart. The weight of the subject P derived here is the derived weight.

[0061] Next, the determination function 57 compares the registered weight with the derived weight and determines whether there is a difference between the registered weight and the derived weight (step S109). The determination function 57 determines that there is no difference between the registered weight and the derived weight if the difference between the registered weight and the derived weight falls within a certain error range, and determines that there is a difference between the registered weight and the derived weight if the difference between the registered weight and the derived weight exceeds the certain error.

[0062] If it is determined that there is a difference between the registered weight and the derived weight, the determination function 57 outputs weight information of the registered weight and the derived weight to the warning function 58. The warning function 58, to which the determination function 57 has output the weight information, outputs warning information to the alarm device 44. The alarm device 44, to which the warning information has been output by the warning function 58, warns the operator and the subject P to select the weight of the subject P (step S111).

[0063] When the operator, having received the warning from the alarm device 44, performs an input operation on the input interface 43, the input interface 43 receives selection information for selecting the weight of the subject P. The calculation function 59 determines weight information to be used when calculating the amount of contrast agent to be administered to the subject P from the weight of the subject P (derived weight or registered weight) corresponding to the selection information received by the input interface 43 (step S113). Next, the calculation function 59 calculates the amount of contrast agent to be administered to the subject P based on the weight of the subject P based on the determined weight information (step S115). If the determination function 57 determines in step S109 that there is no difference in the registered weight, the calculation function 59 calculates the amount of contrast agent to be administered to the subject P based on the weight of the subject P based on the weight information (step S115).

[0064] After the calculation function 59 calculates the amount of contrast agent, the control function 51 determines the scan position of the subject P (step S117) and captures a scanogram (step S119). Subsequently, the operator generates a scan plan by referring to the captured scanogram and inputs information about the generated scan plan by operating the input interface 43 (step S121).

[0065] Then, the control function 51 executes a scan of the subject P (step S123). Furthermore, the control function 51 processes the scanned image data of the subject P by, for example, displaying it on the display 42 (step S125). In this way, the X-ray CT apparatus 1 ends the processing shown in FIG.

[0066] Next, the process of deriving the derived weight in step S107 will be described. Fig. 4 is a flowchart showing an example of the process of deriving the derived weight. In deriving the derived weight, first, the acquisition function 55 acquires a detected value of current based on an electrical signal transmitted by the current sensor 75 (step S201). The acquisition function 55 outputs the acquired detected value of current to the derivation function 56.

[0067] Next, the derivation function 56 receives the displacement amount of the tabletop 33 from the reference position transmitted by the encoder 78 (step S203), and determines whether the displacement amount of the tabletop 33 has changed (step S205). If it is determined that the displacement amount of the tabletop 33 has not changed, the derivation function 56 returns the process to step S201.

[0068] If it is determined that the displacement amount of the tabletop 33 has changed, the deriving function 56 acquires the height position of the tabletop 33 (step S207). The height position acquired here is the height position before the tabletop 33 started to rise. Here, the camera 20 captures an image of the top of the tabletop 33 and transmits an electrical signal of the captured image including the optional items to the processing circuit 50 of the console device 40.

[0069] Next, acquisition function 55 receives the electrical signal of the image transmitted by camera 20 (step S209). Derivation function 56 detects optional items mounted on top board 33 based on the electrical signal of the image transmitted by camera 20, and acquires the weight of the optional item included in the optional item information of the detected optional item (step S211). The processes from step S207 to S211 may be executed before step S205.

[0070] Next, the derivation function 56 calculates the initial torque of the motor 70 based on the acquired current value (step S213). Having calculated the initial torque, the derivation function 56 derives the load applied to the tabletop 33 based on the initial torque of the motor 70 and the height position of the tabletop 33 (step S215).

[0071] Next, the derivation function 56 subtracts the acquired weight of the option item from the calculated load applied to the tabletop 33 to derive the derived weight (step S217). In this embodiment, the derivation function 56 uses a simulator stored in the memory 41 to derive the load applied to the tabletop 33. The simulator will be described later. In this way, the X-ray CT apparatus 1 ends the processing shown in FIG.

[0072] Next, the simulator used when deriving the derived weight will be described. Fig. 5 is a block diagram showing the flow of electrical signals when deriving the derived weight. When deriving the derived weight, electrical signals indicating the current value of the current flowing through the motor 70 and the height of the tabletop 33 are input to the simulator.

[0073] When the subject P gets on the table 33 of the bed device 30, a load corresponding to the body weight of the subject P is applied to the motor 70. Therefore, the torque of the motor 70 changes before and after the table 33 starts to move up and down, and the initial torque changes significantly compared to the torque immediately before. The X-ray CT device 1 detects the weight of the subject P by utilizing the change in torque when the motor 70 outputs the initial torque.

[0074] When adjusting the height position of the tabletop 33, the current value of the current flowing through the motor 70 is increased linearly. The torque of the motor 70 increases in proportion to the increase in the current value. When the torque of the motor 70 exceeds the load applied to the tabletop 33, the tabletop 33 rises. The torque of the motor 70 when the tabletop 33 starts to move up and down is the initial torque.

[0075] The relationship between the change over time in the value of the current flowing through the motor 70 and the speed of the tabletop 33 at this time will be described below. Fig. 6A is a graph showing the change over time in the value of the current flowing through the motor 70. Fig. 6B is a graph showing the change over time in the rising speed of the tabletop 33 in accordance with the change over time in the current flowing through the motor 70. When the value of the current flowing through the motor 70 is increased linearly with time, the tabletop 33 remains stationary and does not rise for a while after the current is passed through the motor 70.

[0076] When the current value of the current flowing through the motor 70 increases, the torque of the motor 70 also increases with the increase in the current value, and for example, at time t1, the torque of the motor 70 reaches the load applied to the tabletop 33. Thereafter, when the current value of the current flowing through the motor 70 increases and the torque of the motor 70 exceeds the load applied to the tabletop 33, the tabletop 33 begins to rise. When the speed of the tabletop 33 reaches the target speed Vm, the tabletop 33 rises at a constant speed. The torque of the motor 70 when the tabletop 33 begins to rise is the initial torque.

[0077] The initial torque of the motor 70 varies depending on the height position of the tabletop 33 and the load applied to the tabletop 33, so each parameter in the simulator can be calculated by simulation. Therefore, by using a simulator that uses the height position of the tabletop 33 and the initial torque of the motor 70 as input parameters and the load for the input conditions as an output parameter, it is possible to calculate the weight of the subject P, which corresponds to the load applied to the tabletop 33.

[0078] The simulator includes a motor output model and a tabletop vertical movement model. The motor output model is a simulation model that receives input of the current value flowing through the motor 70, generates and outputs torque information on the torque output by the motor 70, and outputs the torque information on the torque output by the motor 70. The tabletop vertical movement model is a 1D simulation model that receives input of the torque information output by the motor output model and information on the height position of the tabletop 33, and outputs the load applied to the tabletop 33. The height position of the tabletop 33 is calculated based on the displacement of the tabletop 33, for example.

[0079] The tabletop vertical movement model is a model obtained by extracting the feature quantities of each component part in the bed vertical movement device 32. The feature quantities of each component part in the bed vertical movement device 32 include, for example, items such as length, mass, and rigidity. The tabletop vertical movement model is an example of a third simulation model. The motor output model is an example of a second simulation model.

[0080] The tabletop vertical movement model may be a 1D simulation model that outputs the load applied to the tabletop 33 when torque information output by the motor output model is input, without inputting information on the height position of the tabletop 33. In this case, the tabletop vertical movement model is an example of the first simulation model.

[0081] Here, the tabletop up-and-down movement model will be explained. Fig. 7 is a diagram showing an outline of an example of the tabletop up-and-down movement model M. The tabletop up-and-down movement model M simulates the operation when a first thrust F1 generated by the torque of the motor 70 shown in Fig. 2 pushes the lower end of the first link 61 in the X-link mechanism 60 in a direction away from the motor 70. The first thrust F1 acts in the horizontal direction (Z direction), but by passing through the X-link mechanism 60, it becomes a second thrust F2 that acts in the upward direction (Y direction) to raise the tabletop 33.

[0082] When the current value detected by the current sensor 75 is input to the simulator, the torque of the motor 70 that raises the tabletop 33 is found using the motor output model as the input current value increases. Here, the torque of the motor 70 that raises the tabletop 33 varies depending on the height position of the tabletop 33. For this reason, the tabletop up-and-down movement model is a model that takes the height position of the tabletop 33 into consideration.

[0083] Specifically, the torque of the motor 70 that raises the tabletop 33 decreases as the tabletop 33 moves higher. For this reason, the tabletop up-and-down movement model calculates the torque of the motor 70 to be smaller the higher the height position of the tabletop 33. Therefore, the initial torque of the motor 70 is calculated to be smaller the higher the height position of the tabletop 33.

[0084] Here, an example has been described in which the top plate 33 is raised, but the initial torque of the motor 70 can be calculated in the same way when lowering the top plate 33. As with the case of raising the top plate 33, the torque of the motor 70 that lowers the top plate 33 becomes smaller the higher the top plate 33 is located. Therefore, the initial torque of the motor 70 is calculated to be smaller the higher the height position of the top plate 33 is.

[0085] The relationship between the height position of the top plate 33 and the torque of the motor 70 when the top plate 33 is raised and lowered is shown in the figure. When the top plate 33 is at its lowest point both when the top plate 33 is raised and when it is lowered, the torque of the motor 70 is maximum. When the top plate 33 is at its highest point both when the top plate 33 is raised and when it is lowered, the torque of the motor 70 is minimum.

[0086] The torque of the motor 70 does not increase when the top plate 33 is positioned at any position from the lowest point to the highest point. own weight Since a force is applied in the direction of the arrow, the initial torque during ascent is greater than the initial torque during descent.

[0087] Furthermore, if optional items are mounted on the top board 33, the weight of the optional items will be applied to the top board 33 in addition to the weight of the subject P. Therefore, by subtracting the weight of the optional items from the weight determined using the simulator, the weight of the subject P can be measured without being affected by the optional items. Information about the optional items may be obtained by inputting the information through the input interface 43, in addition to information obtained by capturing an image with the camera 20.

[0088] In the above embodiment, the X-ray CT apparatus 1 measures the weight of the subject P placed on the tabletop 33 based on the detected value of the current of the motor 70, which is torque information related to the initial torque. Therefore, the weight of the subject P can be measured without providing a separate sensor such as a load cell. Therefore, the weight of the subject P placed on the bed can be measured with a simple configuration.

[0089] Furthermore, the X-ray CT apparatus 1 derives the initial torque further based on the position of the top 33. Therefore, the height position of the top 33 can be set to any position at the start position of measuring the weight of the subject P without being restricted by the height of the top 33. Furthermore, the initial torque of the motor 70 when starting to move the top 33 can be derived with high accuracy.

[0090] Furthermore, the tabletop 33 is supported by a support frame 34 so as to be movable in its longitudinal direction, and the support frame 34 supports the tabletop 33 so as to be movable in the vertical direction via an X-link mechanism 60. The initial torque of the motor 70 varies depending on the height position of the tabletop 33. Therefore, by deriving the initial torque based additionally on the height position of the tabletop 33, the initial torque can be derived with even greater accuracy.

[0091] Furthermore, when measuring the weight of the subject P, the X-ray CT apparatus 1 acquires the weight of optional items mounted on the top board 33, and calculates and measures the weight of the subject P by subtracting the weight of the optional items from the load applied to the top board 33. Therefore, even when optional items are mounted on the top board 33, the weight of the subject P can be measured with high accuracy.

[0092] Furthermore, the X-ray CT apparatus 1 derives the weight of the subject P using a simulation model, such as a motor output model or a tabletop vertical movement model, with initial torque information as an input parameter. This reduces the effort required to derive the weight of the subject P. A lookup table may be used instead of or in addition to the simulation model. In this case, the lookup table may be a table that stores, for example, the load (or the weight of the subject P) applied to the tabletop 33 according to the initial torque of the motor 70 for every 1 cm of the height position of the tabletop 33. When a lookup table is used, the accuracy of the derived weight varies depending on the amount of data, so it is preferable to use a simulation model.

[0093] Furthermore, the X-ray CT apparatus 1 measures the weight of the subject P during the flow of capturing a contrast CT image. Therefore, even if the subject P is a patient who cannot stand up and have their weight measured, a separate stretcher or the like can be used, eliminating the need to measure their weight. Furthermore, the weight of the subject P placed on the tabletop 33 is measured to determine the amount of contrast agent to be administered to the subject P. Therefore, the amount of contrast agent to be administered to the subject P can be appropriate. Furthermore, since the weight of the subject P is measured while the subject P is still placed on the tabletop 33, it is possible to prevent the patient, who is the subject P, from realizing that his / her weight is being measured. Therefore, the physical and mental burden on the patient can be reduced.

[0094] Furthermore, if there is a difference between the derived weight and the registered weight, the alarm device 44 of the X-ray CT apparatus 1 warns the operator or the subject P of the difference. This prevents the subject P from underreporting his or her weight.

[0095] In the X-ray CT apparatus 1 of the above embodiment, the torque of the motor 70 is transmitted to the tabletop 33 via the bed vertical movement device 32 having the X-link mechanism 60, but the torque of the motor 70 of the tabletop 33 may be transmitted directly to the X-link mechanism 60 without going through the support frame 34. Furthermore, the bed vertical movement device 32 may include a transmission mechanism other than the X-link mechanism 60. Below, as a modified example, a transmission mechanism other than the X-link mechanism 60 will be described.

[0096] (Modification 1: Bed vertical movement device equipped with first parallel link mechanism 80) 8 is a diagram showing an overview of the first parallel link mechanism 80. The first parallel link mechanism 80 includes a front parallel link 81 and a rear parallel link 82. The lower ends of the front parallel link 81 and the rear parallel link 82 are each pin-connected to a base 83, and the upper ends of the front parallel link 81 and the rear parallel link 82 are each pin-connected to a top plate 84.

[0097] A hydraulic cylinder 85 is connected to the rear parallel link 82, and the rear parallel link 82 can be swung around the lower end of the link by the hydraulic cylinder 85. As shown by the solid line in Figure 8, the rear parallel link 82 stands up when the cylinder rod of the hydraulic cylinder 85 extends.

[0098] 8, the rear parallel link 82 is lowered when the cylinder rod of the hydraulic cylinder 85 is retracted. The front parallel link 81 swings while maintaining a parallel state with the second parallel link in accordance with the swing of the rear parallel link 82. As the front parallel link 81 and the rear parallel link 82 swing, the top plate 84 moves forward and backward and up and down while maintaining a parallel state with the floor surface.

[0099] In a bed raising / lowering device equipped with the first parallel link mechanism 80, similar to the X-link mechanism 60 shown in the embodiment, the driving force (torque) of the hydraulic cylinder 85 that raises the tabletop 84 decreases as the height position of the tabletop 84 increases. Therefore, the initial torque of the hydraulic cylinder 85 is calculated to decrease as the height position of the tabletop 84 increases.

[0100] Similarly, when lowering the tabletop 84, the initial torque of the hydraulic cylinder 85 is calculated to be smaller the higher the height position of the tabletop 84. The relationship between the height position of the tabletop 84 and the torque of the hydraulic cylinder 85 when raising and lowering the tabletop 84 is the same as the relationship between the height position of the tabletop 33 and the torque of the motor 70 in the above embodiment.

[0101] (Modification 2: Bed vertical movement device equipped with second parallel link mechanism 90) 9 is a diagram showing an overview of the second parallel link mechanism 90. The second parallel link mechanism 90 includes a front parallel link 91 and a rear parallel link 92. The lower ends of the front parallel link 91 and the rear parallel link 92 are each pin-connected to a base 93, and the upper ends of the front parallel link 91 and the rear parallel link 92 are each pin-connected to a top plate 94.

[0102] One end (upper end) of an auxiliary link 95 is pin-connected to approximately the center of the longitudinal direction of the rear parallel link 92. The other end (lower end) of the auxiliary link 95 is pin-connected to a slider 96 that is slidable relative to the base 93. An actuator 97 is provided on the side of the slider 96. The actuator 97 is, for example, a jack. The actuator 97 can slide the slider 96.

[0103] The lower ends of the front parallel link 91 and the rear parallel link 92 are disposed on the opposite side of the actuator 97 from the lower end of the auxiliary link 95. The lower end of the front parallel link 91 is disposed at a position farther from the actuator 97 than the lower end of the rear parallel link 92.

[0104] When the actuator 97 moves the slider 96 in a direction approaching the actuator 97, the auxiliary link 95 pushes up the rear parallel link 92, as shown by the imaginary line in Figure 9. When the rear parallel link 92 is pushed up, the front parallel link 91 is also pushed up, and the front parallel link 91 and rear parallel link 92 maintain a parallel state.

[0105] When the actuator 97 moves the slider 96 away from the actuator 97, the auxiliary link 95 pulls down the rear parallel link 92, as shown by the solid line in Figure 9. When the rear parallel link 92 is pulled down, the front parallel link 91 is also pulled down, and the front parallel link 91 and the rear parallel link 92 maintain a parallel state. In this way, the front parallel link 91 and the rear parallel link 92 swing while maintaining a parallel state, and the top plate 94 moves forward and backward and up and down.

[0106] In a bed raising / lowering device equipped with the second parallel link mechanism 90, similar to the X-link mechanism 60 shown in the embodiment, the driving force (torque) of the actuator 97 that raises the tabletop 94 decreases as the height position of the tabletop 94 increases. Therefore, the initial torque of the actuator 97 is calculated to decrease as the height position of the tabletop 94 increases.

[0107] Similarly, when lowering the tabletop 94, the initial torque of the actuator 97 is calculated to be smaller the higher the height position of the tabletop 84. The relationship between the height position of the tabletop 94 and the torque of the actuator 97 when raising and lowering the tabletop 94 is the same as the relationship between the height position of the tabletop 33 and the torque of the motor 70 in the above embodiment.

[0108] In the above embodiment, the X-ray CT apparatus 1 uses the detected value of the current of the motor 70 as the torque information, but the torque of the motor 70 may be detected by a torque sensor, and the detected value of the torque may be used as the torque information. In this case, when the simulator shown in Fig. 5 is used, the motor output model is not required.

[0109] Furthermore, in the above-described embodiment and modified examples, the weight of the subject P is derived based on the initial torque of a driving source such as the motor 70 when the top 33 moves in the vertical direction. Alternatively, the weight of the subject P may be derived based on the torque of the driving source when the top 33 moves in a direction other than the vertical direction, for example, horizontally. Furthermore, the weight of the subject P may be finally determined by combining the weights of the subject P derived based on the torque of the driving source when the top 33 moves in multiple directions. For example, the weight of the subject P derived when the top 33 moves in the horizontal direction may be used as auxiliary data to determine the weight of the subject P derived when the top 33 moves in the vertical direction.

[0110] Furthermore, in the above-described embodiment and modified examples, the derivation function 56 detects the weight of the subject P using the first or third simulation model and the second simulation model, with at least the current value flowing through the motor 70 as input and the load applied to the top 33 as output. Alternatively, the derivation function 56 may derive the weight of the subject P using simulation models other than these. For example, the derivation function 56 may derive the weight of the subject P based on the load output by a fourth simulation model that derives the load applied to the top 33 when the current value of the current flowing through the motor 70 is input. Alternatively, the derivation function 56 may derive the weight of the subject P based on the load output by a fifth simulation model that derives the load applied to the top 33 when the current value of the current flowing through the motor 70 and information on the height position of the top 33 are input.

[0111] In the above embodiment and modified examples, an X-ray CT device 1 is exemplified as a medical image diagnostic device, but the medical image diagnostic device may be a device other than the X-ray CT device 1. The medical image diagnostic device may be, for example, a PET (positron emission tomography)-CT device, an MRI (magnetic resonance imaging) device, an angiography device, or the like.

[0112] According to at least one of the embodiments described above, the driving source that drives the bed on which the subject to be imaged sits has an acquisition unit that acquires torque information related to the torque when starting to move the bed, and a derivation unit that derives the weight of the subject based on the torque information acquired by the acquisition unit, thereby making it possible to measure the weight of the subject sitting on the bed with a simple configuration.

[0113] Although several embodiments 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, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0114] 1...X-ray CT device 10... Mounting device 11...X-ray tube 12...Wedge 13...Collimator 14...X-ray high voltage device 15...X-ray detector 16…DAS 17...Rotating frame 18...Control device 20...Camera 21...1st camera 22...Second camera 30...Bed device 31...Foundation 32...Bed up / down device 33...Tabletop 34...Support frame 40...Console device 41...Memory 42...Display 43...Input interface 44...Alarm device 50...Processing circuit 51...Control function 52...Pre-processing function 53...Reconstruction processing function 54...Image processing function 55...Acquisition function 56...Derived Function 57...Decision function 58...Warning function 59...Calculation function 60...X-link mechanism 70...Motor 75...Current sensor 78...Encoder 80...First parallel link mechanism 90...Second parallel link mechanism F1…1st thrust F2…Second thrust M...Top plate vertical movement model P...Subject t1…Time Vm…Target speed

Claims

1. a top plate on which a subject to be imaged sits; a bed device that supports the tabletop so as to be movable in the vertical direction by transmitting torque from a drive source via a drive force transmission mechanism having an X-link mechanism; an acquisition unit that acquires torque information related to a torque when starting to move the tabletop and height position information related to a height position of the tabletop when starting to move the tabletop; a derivation unit that derives a weight of the subject based on the torque information and the height position information, the torque information includes a current value of a current flowing through the drive source, the derivation unit calculates and derives a torque of the drive source when starting to move the tabletop based on the current value; the deriving unit derives the torque of the driving source when starting to move the tabletop based on both the current value and the position of the tabletop. Medical imaging diagnostic equipment.

2. The acquisition unit further acquires the weight of an accessory mounted on the top plate, the deriving unit calculates a load applied to the tabletop based on the torque information acquired by the acquiring unit, and derives a weight of the subject by subtracting a weight of the accessory from the calculated load applied to the tabletop. The medical image diagnostic apparatus according to claim 1 .

3. the deriving unit derives the weight of the subject based on the load output by a first simulation model that outputs a load applied to the top board when torque information for starting to move the top board is input.

3. The medical image diagnostic apparatus according to claim 1.

4. the derivation unit derives the weight of the subject based on the load output by a third simulation model that outputs a load applied to the top board when torque information at the time of starting to move the top board and information on a height position of the top board are input. The medical image diagnostic apparatus according to any one of claims 1 to 3.

5. the derivation unit generates the torque information based on the current value by using a second simulation model that outputs a torque when starting to move the tabletop when a current value of the current flowing through the drive source is input.

5. The medical image diagnostic apparatus according to claim 3.

6. the derivation unit derives the weight of the subject based on the load output by a fourth simulation model that derives the load applied to the top board when a current value of the current flowing through the drive source is input. The medical image diagnostic apparatus according to any one of claims 1 to 3.

7. the derivation unit derives the weight of the subject based on the load output by a fifth simulation model that derives the load applied to the top plate when a current value of a current flowing through the drive source and information on a height position of the top plate are input. The medical image diagnostic apparatus according to any one of claims 1 to 3.

8. a top plate on which a subject to be imaged sits; a bed device that supports the tabletop so that the tabletop can move up and down by transmitting torque from a drive source via a drive force transmission mechanism that includes an X-link mechanism, acquiring torque information relating to a torque when starting to move the tabletop and height position information relating to a height position of the tabletop when starting to move the tabletop; deriving a weight of the subject based on the torque information and the height position information; the torque information includes a current value of a current flowing through the drive source, the computer calculates and derives a torque of the drive source when starting to move the tabletop based on the current value; the computer derives the torque of the drive source when starting to move the tabletop based on both the current value and the position of the tabletop. Medical imaging diagnostic methods.

9. a top plate on which a subject to be imaged sits; a bed device that supports the tabletop so that the tabletop can move up and down by transmitting torque from a drive source via a drive force transmission mechanism that includes an X-link mechanism, acquiring torque information relating to a torque when starting to move the tabletop and height position information relating to a height position of the tabletop when starting to move the tabletop; deriving a weight of the subject based on the torque information and the height position information; the torque information includes a current value of a current flowing through the drive source, causing the computer to calculate and derive a torque of the drive source when starting to move the tabletop based on the current value; causing the computer to derive a torque of the driving source when starting to move the tabletop based on both the current value and the position of the tabletop; program.

Images