Operation sound suppression device and x-ray tomographic image capturing device

Abstract

To provide an operation sound suppression device capable of suppressing operation sound when an operator and a subject have a conversation at the time of imaging by an X-ray tomographic image capturing device, and an X-ray tomographic image capturing device applied with the operation sound suppression device.SOLUTION: An operation sound suppression device used in an X-ray tomographic image capturing device includes: a detection part that detects a conversation between an operator of the X-ray tomographic image capturing device and a subject lying on a bed of the X-ray tomographic image capturing device, or a situation where a conversation between them is possible; and a fan control part that controls operation of one or more cooling fans provided in the X-ray tomographic image capturing device on the basis of a detection result of the detection part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an operation noise suppression device used in an X-ray tomography apparatus, and to an X-ray tomography apparatus equipped with an operation noise suppression device. [Background technology]

[0002] In a medical imaging system, a subject (examinee) placed on a bed is irradiated with electromagnetic waves (RF pulses) or X-rays to obtain a tomographic image of the subject. Since the subject needs to be placed in an appropriate position on the bed to obtain an appropriate tomographic image, communication such as conversation may take place between the operator of the medical imaging system and the subject before and during imaging.

[0003] Because medical imaging systems generate relatively loud operating noises from built-in devices, it can be difficult for the operator and the subject to hear each other when communicating. For example, if the subject has difficulty hearing instructions from the operator, the operator may have to repeat the same instructions, which increases the effort required for imaging and may lengthen the time it takes to perform the imaging.

[0004] To address this issue, it is conceivable to use an emergency stop switch provided in the medical imaging system to stop the operation of the medical imaging system and reduce the operating noise when communicating. However, the method using the emergency stop switch has the problem that, because the power supply is cut off, it takes a long time to reset the medical imaging system to the state it was in before the emergency stop, as initial values ​​must be reset when the system is restarted.

[0005] In consideration of the above problems, for example, Patent Document 1 discloses an MRI apparatus (nuclear magnetic resonance imaging apparatus) including an imaging pause command generating means that generates a command to pause imaging, an imaging pause means that pauses the operation of at least a gradient magnetic field generating means in response to a command from the imaging pause command generating means, and an imaging resume command generating means that generates a command to resume imaging paused by the imaging pause means. Because the imaging pause means pauses the operation of the gradient magnetic field generating means to silence the sound of applying the gradient magnetic field, the MRI apparatus described in Patent Document 1 can reduce operating noise when communicating without cutting off the power supply to the MRI apparatus.

[0006] Furthermore, for example, Patent Document 2 discloses an X-ray tomography apparatus (X-ray CT apparatus) having multiple fans, a position sensor, a position information acquisition unit, and a control unit. The position sensor is a motion sensor placed near the front of the operation panel, and measures position information indicating whether an operator is near the front of the operation panel. The position information acquisition unit acquires the position information, and the control unit controls the rotation speed or direction of each fan based on the acquired position information. As a result, the X-ray CT apparatus described in Patent Document 2 can reduce noise in the voice emitted by the operator. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-275221 [Patent Document 2] Japanese Patent Application Publication No. 2019-130222 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the technology described in Patent Document 1, in order to suppress the operating noise of the MRI apparatus, the operation of the gradient magnetic field generating means is temporarily stopped to eliminate the sound of applying the gradient magnetic field. Therefore, there is a problem that it cannot be applied to medical imaging systems that do not use RF pulses. Furthermore, there is a problem that Patent Document 2, in which the operating noise is reduced according to the position information of the operator, cannot adequately accommodate conversations between the operator and the subject.

[0009] The present invention has been made to solve the above-mentioned problems, and aims to provide an operation noise suppression device that can suppress operation noise when an operator and a subject are conversing during imaging with an X-ray tomography device, and an X-ray tomography device to which an operation noise suppression device is applied. [Means for solving the problem]

[0010] The operating noise suppression device used in the X-ray tomography apparatus according to the first aspect includes a detection unit that detects a conversation or a situation in which a conversation is possible between an operator of the X-ray tomography apparatus and a subject placed on a bed of the X-ray tomography apparatus, and a fan control unit that controls the operation of one or more cooling fans provided in the X-ray tomography apparatus based on the detection result of the detection unit.

[0011] According to the second aspect, in the operation noise suppression device of the first aspect, the detection unit includes a bed imaging unit that captures an image of the vicinity of the bed, and the detection unit detects a situation in which conversation between the operator and the subject is possible based on the distance between the operator and the subject in the image captured by the bed imaging unit.

[0012] According to the third aspect, in the operation noise suppression device according to the first or second aspect, the detection unit includes a first sound collection unit that collects sounds near the bed, and the detection unit detects a conversation between the operator and the subject based on the sounds collected by the first sound collection unit.

[0013] According to a fourth aspect, in an operation noise suppression device according to any one of the first to third aspects, the detection unit includes a second sound collection unit that collects sounds near an operation unit that operates imaging by an X-ray tomography device, and the detection unit detects a conversation between an operator and a subject based on the sounds collected by the second sound collection unit.

[0014] According to a fifth aspect, in the operation noise suppression device according to any one of the first to fourth aspects, the fan control unit reduces the rotation speed of at least one of the one or more cooling fans based on the detection result by the detection unit.

[0015] According to a sixth aspect, in the operation noise suppression device according to any one of the first to fifth aspects, the fan control unit temporarily stops at least one of the one or more cooling fans based on the detection result by the detection unit.

[0016] An X-ray tomography apparatus according to a seventh aspect includes one or more cooling fans and an operation noise suppression device according to any one of the first to sixth aspects. [Effects of the Invention]

[0017] Since the operating noise can be suppressed when an operator and a subject are talking during imaging using the X-ray tomography apparatus, the operator and the subject can talk smoothly. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view illustrating the overall appearance of an X-ray CT apparatus. [Figure 2] FIG. 2 is a schematic diagram illustrating the inside of a gantry. [Figure 3] FIG. 2 is a functional block diagram of the operation noise suppression device. [Figure 4] 1 is a schematic configuration diagram of an X-ray CT apparatus to which an operation noise suppression device according to a first embodiment is applied. [Figure 5] FIG. 10 is a schematic configuration diagram of an X-ray CT apparatus to which an operation noise suppression device according to a second embodiment is applied. [Figure 6] It is a schematic configuration diagram of an X-ray CT apparatus to which an operation noise suppression apparatus according to a third embodiment is applied.

Embodiments for Carrying Out the Invention

[0019] <Schematic Configuration of X-ray CT Apparatus> First, the general schematic configuration of an X-ray computed tomography apparatus to which the operation noise suppression apparatus according to the present disclosure is applied will be described with reference to FIGS. 1 and 2. Hereinafter, the X-ray computed tomography apparatus will be referred to as an X-ray CT (Computed Tomography) apparatus. In FIGS. 1 and 2, the three-dimensional coordinate system shows an example of the definition of directions in the X-ray CT apparatus 1. The X-axis, Y-axis, and Z-axis of the three-dimensional coordinate system are examples and are not limited thereto. Here, the Z-axis direction is the body axis direction of the subject S. The Y-axis direction is the vertical direction of the subject S and is a direction parallel to the gravitational direction. The X-axis direction is the left-right direction of the subject S and is a horizontal direction orthogonal to the gravitational direction.

[0020] FIG. 1 is an external view of the X-ray CT apparatus 1. As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry 20, a couch 3, and an operation unit 30. In a general X-ray CT apparatus 1, the gantry 20 and the couch 3 are provided in the imaging room, and the operation unit 30 is provided at a position separated from the imaging room, for example, in the operation room. The subject S is placed on the couch 3. The gantry 20 incorporates equipment for irradiating X-rays and is configured to be rotatable around the couch 3. Further, an opening 21 through which the couch 3 can pass is formed near the center of the gantry 20. The operation unit 30 is a device for an operator OP to operate the X-ray CT apparatus 1.

[0021] FIG. 2 is a schematic configuration diagram of the inside of the gantry 20. As shown in FIG. 2, the gantry 20 includes a rotating disk 7 having a substantially annular shape, a fixed frame (not shown) that supports the rotating disk 7 via a bearing (not shown), and a stationary side stand 6 that supports the fixed frame.

[0022] The turntable 7 is supported by a fixed frame so as to be rotatable around the rotation axis. The turntable 7 is connected to a large pulley (not shown) via the rotating side (inner ring) of a bearing. The turntable control device 8 is fixed in a position close to the stationary stand 6. A drive belt 16 is wound around the outer periphery of the large pulley and the outer periphery of a small pulley (not shown) of the turntable control device 8. When the turntable control device 8 drives the small pulley to rotate, the large pulley rotates via the drive belt 16. The rotational force of the large pulley is transmitted to the turntable 7 via the inner ring of the bearing, and the turntable 7 is driven to rotate around the rotation axis. The turntable control device 8 is, for example, a motor.

[0023] The turntable 7 is equipped with a plurality of components, such as an X-ray tube assembly 4, an X-ray detector 5, an X-ray control device 11, a high-voltage generator 12, a scanner control device 13, a collimator 14, and a cooler 15. These components rotate together with the turntable 7.

[0024] The X-ray tube device 4 irradiates X-rays onto a subject S placed on a bed 3. The collimator 14 limits the radiation range of the X-rays 2 irradiated from the X-ray tube device 4.

[0025] The X-ray detector 5 is disposed opposite the X-ray tube assembly 4 on the turntable 7. The X-ray detector 5 measures the spatial distribution of transmitted X-rays by detecting X-rays that are irradiated from the X-ray tube assembly 4 and transmitted through the subject S. The X-ray detector 5 has a large number of X-ray detection elements arranged in the rotation direction of the turntable 7, or arranged in two directions: the rotation direction of the turntable 7 and the direction of the rotation axis. Since the sensitivity of the X-ray detection elements is temperature dependent, one or more cooling fans 19 are provided near the X-ray detector 5 to suppress temperature changes in the X-ray detector 5.

[0026] The X-ray control device 11 controls the power input to the X-ray tube device 4. The high-voltage generator 12 applies or supplies to the X-ray tube device 4 a tube voltage and a tube current corresponding to a control signal transmitted from the X-ray control device 11. X-ray conditions such as the tube voltage and the tube current are selected or input by an operator OP via an input device 31. The scanner control device 13 controls the collimator 14 and the X-ray detector 5, etc.

[0027] Generally, the efficiency of X-ray generation in the X-ray tube assembly 4 is about 1%, and the remaining 99% or so of the energy is converted into heat, so it is necessary to remove the heat generated from the X-ray tube assembly 4 (to cool the X-ray tube assembly 4). The cooler 15 cools the X-ray tube assembly 4 to a predetermined temperature or below. The cooler 15 may be of a water-cooled type or an oil-cooled type. The cooler 15 includes, for example, a radiator and a pump, and the radiator is provided with one or more cooling fans 18.

[0028] The cooling fan 18 provided in the cooler 15 of the X-ray tube assembly 4 starts rotating when the temperature of the X-ray tube assembly 4 reaches a preset operation start temperature, and generally continues rotating for a predetermined period of time.

[0029] The DC power supply device 9 generates a DC voltage based on an AC voltage from a power supply facility installed in an inspection room, etc. The DC voltage is transmitted to the rotating disk 7 via a slip ring 10.

[0030] Furthermore, one or more air intake ports 23 are formed below the housing of the gantry 20 to allow air to flow in from the outside, and one or more exhaust ports 22 are provided above the housing of the gantry 20 to exhaust air from inside the gantry 20. One or more ceiling fans (cooling fans) 17 are provided near the exhaust ports 22. Because heated air rises, the interior of the gantry 20 can be cooled effectively by using the ceiling fans 17.

[0031] Furthermore, the gantry 20 includes a control board (not shown). For example, the control board reads status information such as the temperature of each device provided in the gantry 20, such as the X-ray tube assembly 4 and the X-ray detector 5, and the internal temperature of the gantry 20, and performs integrated control of each device in the gantry 20 based on the status information.

[0032] The operation unit 30 includes an input device 31, a display device 32, and a housing 33. An image processing device (not shown) and a storage device (not shown) are provided inside the housing 33. The input device 31 is an input interface that allows the operator OP to perform imaging operations. For example, the input device 31 is a keyboard or a pointing device. The image processing device processes measurement data detected by the X-ray detector 5 to generate a CT image. The display device 32 is a device that displays the CT image created by the image processing device, and is, for example, a liquid crystal display. The storage device is a device that stores data collected by the X-ray detector 5 and the CT image created by the image processing device, and is, for example, an HDD (Hard Disk Drive).

[0033] <Principle of operation noise suppression device> Next, the principle of the operation noise suppression device 40 according to the present disclosure will be described with reference to Fig. 3. First, the cooling fans 17, 18, and 19 start rotating when their respective preset states are reached. The operation noise of these cooling fans 17, 18, and 19 accounts for a large proportion of the operation noise of the X-ray CT scanner 1.

[0034] The X-ray tube assembly 4 of the X-ray CT system 1 has a value called heat capacity (maximum heat capacity) that indicates how much X-rays the X-ray tube assembly 4 can output. When X-rays are emitted from the X-ray tube assembly 4, the amount of accumulated heat increases according to the X-ray output. When the ratio of the accumulated heat to the maximum heat capacity (heat accumulation rate) reaches 100%, this indicates that the heat is saturated. Once the heat is saturated, it is necessary to wait for the X-ray tube assembly 4 to cool down before the next X-ray emission. However, in order to emit the next X-rays, it is not necessary to wait until the heat accumulation rate of the X-ray tube assembly 4 reaches 0%. It is sufficient to wait until the X-ray tube assembly 4 has cooled down by an amount equivalent to the output of the X-rays to be emitted next. For example, if the output of the X-rays to be emitted next corresponds to 10% of the maximum heat capacity, the next X-ray emission can be performed by waiting until the heat accumulation rate of the X-ray tube assembly 4 reaches 90%.

[0035] The cooling fan 18 starts rotating when the temperature of the X-ray tube assembly 4 reaches or exceeds a predetermined operation start temperature. Typically, once X-rays are irradiated, the cooling fan 18 is controlled to continue rotating for several tens of minutes, for example, 50 minutes. However, in many cases, an X-ray tube assembly 4 having a maximum heat capacity large enough to minimize or eliminate the cooling wait time is selected, taking into account the frequency of use of the X-ray CT system 1. Therefore, for example, if the heat accumulation rate of the X-ray tube assembly 4 is equal to or less than a certain value (equal to or less than a reference heat accumulation rate RHR, which will be described later), it is considered that stopping the cooling fan 18 of the cooler 15 that cools the X-ray tube assembly 4 only while the operator OP and the subject S are talking does not pose a major problem.

[0036] Similarly, the ceiling fan 17 starts rotating when the internal temperature of the gantry 20 reaches or exceeds a predetermined operation start temperature. However, since there is no need to lower the temperature inside the gantry 20 more than necessary, for example, if the temperature inside the gantry 20 is below a certain temperature (below a reference internal temperature RTG, which will be described later), it is thought that there will be no major problem if the ceiling fan 17 is stopped only while the operator OP and the subject S are talking.

[0037] Similarly, the cooling fan 19 starts rotating when the temperature of the X-ray detector 5 reaches or exceeds a predetermined operation start temperature. However, since there is no need to lower the temperature of the X-ray detector 5 more than necessary, for example, when the temperature of the X-ray detector 5 is below a certain temperature (below a reference temperature RTD, which will be described later), it is thought that stopping the cooling fan 19 only while the operator OP and the subject S are talking will not cause any major problems.

[0038] From such considerations, when the operation noise suppression device 40 according to the present disclosure detects a conversation between the operator OP and the subject S or a situation in which a conversation is possible, it performs control to temporarily suspend the operation or reduce the rotation speed of at least one of the cooling fans 17, 18, 19 if there is no problem with the operation of the X-ray CT device 1. This suppresses the operation noise of the X-ray CT device 1, making it possible for the operator OP and the subject S to have a smooth conversation.

[0039] Here, "detection of a conversation between the operator OP and the subject S" is performed based on the voice and mouth movements of the operator OP or the subject S. "Detection of a situation in which a conversation between the operator OP and the subject S is possible" is performed based on position information (distance) and the start of operation of a predetermined function. These will be described in detail later.

[0040] Fig. 3 is a functional block diagram of an operation noise suppression device 40. As shown in Fig. 3, the operation noise suppression device 40 includes a detection unit 41 and a fan control unit 45. The detection unit 41 detects whether a conversation is occurring or whether a conversation is possible between an operator OP of the X-ray CT device 1 and a subject S placed on the bed 3.

[0041] The fan control unit 45 is connected to a control board (not shown) of the gantry 20. The connection between the fan control unit 45 and the control board may be wired or wireless. The fan control unit 45 controls the operation of one or more cooling fans 17, 18, and 19 provided in the X-ray CT apparatus 1 based on the detection result of the detection unit 41.

[0042] More specifically, the fan control unit 45 includes a storage unit (memory) (not shown) that stores one or more reference values ​​for determining whether or not to temporarily suspend the operation of one or more of the cooling fans 17, 18, and 19 (or whether or not to reduce the rotation speed).

[0043] For example, as one or more reference values, the memory unit stores a predetermined reference heat accumulation rate RHR for the X-ray tube assembly 4, a predetermined reference internal temperature RTG for the gantry 20, and a predetermined reference temperature RTD for the X-ray detector 5.

[0044] The reference heat accumulation rate RHR indicates the heat accumulation rate of the X-ray tube assembly 4 at which it is believed that there will be no problems even if the cooling fan 18 of the cooler 15 is temporarily stopped during imaging with the X-ray CT system 1. The reference internal temperature RTG indicates the internal temperature of the gantry 20 at which it is believed that there will be no problems even if the ceiling fan 17 is temporarily stopped. The reference temperature RTD indicates the temperature of the X-ray detector 5 at which it is believed that there will be no problems even if the ceiling fan 17 is temporarily stopped. The reference heat accumulation rate RHR, the reference internal temperature RTG, and the reference temperature RTD are set at the time of shipment of the operation noise suppression device 40 or by the operator OP, depending on the specifications and usage conditions of the X-ray CT system 1. These reference values ​​can be changed as appropriate.

[0045] When the detection unit 41 detects that the operator OP and the subject S placed on the bed 3 are talking or are able to talk, the fan control unit 45 acquires status information including the heat accumulation rate of the X-ray detector 5, the internal temperature of the gantry 20, and the temperature of the X-ray detector 5 via the control board of the gantry 20. Then, when the fan control unit 45 determines that the heat accumulation rate of the X-ray detector 5, the internal temperature of the gantry 20, and the temperature of the X-ray detector 5 are equal to or lower than the reference heat accumulation rate RHR, the reference internal temperature RTG, and the reference temperature RTD, it outputs an instruction to the control board of the gantry 20 to temporarily suspend the cooling fans 17, 18, and 19, for example.

[0046] In this example, the fan control unit 45 controls the operation of the cooling fans 17, 18, and 19 to temporarily stop all of them. However, the operation control of the cooling fans 17, 18, and 19 by the fan control unit 45 is not limited to this example. Other examples will be described later.

[0047] As described above, the cooling fans 17, 18, and 19 are sources of louder operating noise than other devices in the X-ray CT apparatus 1. The operating noise suppression device 40 controls the operation of the cooling fans 17, 18, and 19 based on the detection result of a conversation between the operator OP and the subject S detection unit 41 or a situation where a conversation is possible, thereby suppressing the operating noise so that the operator OP and the subject S can have a smooth conversation.

[0048] 3, for example, the operation noise suppression device 40 is provided separately from the gantry 20. However, the operation noise suppression device 40 may be provided inside the gantry 20. Furthermore, the operation noise suppression device 40 may be provided in an imaging room (not shown) or an operation room (not shown).

[0049] First Embodiment 4 to 6, the X-ray CT apparatus 1 to which the operation noise suppression device 40 is applied will be specifically described below. In the preparation stage for imaging, the operator OP explains to the subject S important points to note, such as holding their breath during imaging. However, the operation noise of the X-ray CT apparatus 1 is loud, so the subject S may have difficulty hearing the explanation. Preferably, the first embodiment is applied when a conversation takes place between the operator OP and the subject S near the bed 3 in the imaging room.

[0050] 4 is a schematic configuration diagram of an X-ray CT apparatus 1 to which an operation noise suppression device 40 according to the first embodiment is applied. As shown in FIG. 4, the detection unit 41 includes a bed imaging unit 42 that captures images of the vicinity of the bed 3. Preferably, the bed imaging unit 42 is disposed on the ceiling above the bed 3, and has an angle of view that can include almost the entire bed 3 in the imaging range. The bed imaging unit 42 captures images (sequential images or video) of the bed 3 at predetermined time intervals or continuously.

[0051] The detection unit 41 calculates the distance between the subject S on the bed 3 and the operator OP based on the image captured by the bed imaging unit 42, and if the distance is equal to or less than a predetermined value (for example, equal to or less than one meter), detects that the subject S and the operator OP are in a state where they can talk to each other. The detection unit 41 outputs the detection result to the fan control unit 45.

[0052] The fan control unit 45 controls the operation of at least one of the cooling fans 17, 18, and 19 so as to suppress the operating noise of the X-ray CT apparatus 1. Examples of the operation control of the cooling fans 17, 18, and 19 include the following.

[0053] (1) For example, the fan control unit 45 temporarily stops the rotation of all of the cooling fans 17, 18, and 19. In this case, the operating noise can be effectively suppressed.

[0054] Specifically, the fan control unit 45 acquires status information via the control board of the gantry 20. Then, when the fan control unit 45 determines based on the status information that the heat accumulation rate of the X-ray detector 5, the internal temperature of the gantry 20, and the temperature of the X-ray detector 5 are equal to or lower than the reference heat accumulation rate RHR, the reference internal temperature RTG, and the reference temperature RTD, respectively, the fan control unit 45 outputs an instruction to the control board of the gantry 20 to temporarily suspend the cooling fans 17, 18, and 19.

[0055] (2) For example, the fan control unit 45 may reduce the rotation speed of the cooling fans 17, 18, and 19 instead of temporarily suspending the rotation. More specifically, the fan control unit 45 may reduce the rotation speed of the cooling fans 17, 18, and 19 to a predetermined value, for example, 75% of the rated rotation speed. Note that this predetermined value may be set in advance, or may be set and changed as appropriate by the operator OP.

[0056] (3) For example, the fan control unit 45 may temporarily suspend the operation of at least one of the cooling fans 17, 18, and 19. For example, by cooling the cooling fan that generates the loudest operating noise among the cooling fans 17, 18, and 19, it is possible to suppress the operating noise while maintaining a certain level of cooling capacity. Specifically, depending on the specifications of the X-ray CT apparatus 1, if the operating noise of the ceiling fan 17 is the loudest, the operation of the ceiling fan 17 may be temporarily suspended.

[0057] In this case, when the fan control unit 45 determines based on the status information that the internal temperature of the gantry 20 is equal to or lower than the reference internal temperature RTG, it outputs an instruction to the control board of the gantry 20 to temporarily stop the ceiling fan 17. This makes it possible to suppress operating noise while maintaining a certain level of cooling capacity.

[0058] Alternatively, the cooling fans 17, 18, and 19 may be prioritized according to the volume of their operating noise, and the operation of at least one of the cooling fans 17, 18, and 19 may be temporarily stopped in accordance with the priority based on the status information.

[0059] Specifically, depending on the specifications of the X-ray CT apparatus 1, if the operating noises of the ceiling fan 17, the cooling fan 18, and the cooling fan 19 are louder in this order, the ceiling fan 17 may be stopped first, and if the ceiling fan 17 cannot be stopped temporarily, the cooling fan 18 may be stopped temporarily. In this case, too, the operating noises can be suppressed while maintaining a certain level of cooling capacity. Note that this order of priority is merely an example.

[0060] (4) For example, the fan control unit 45 may reduce the rotation speed of at least one of the cooling fans 17, 18, and 19 instead of temporarily suspending the rotation operation.

[0061] Furthermore, the operation controls described in (1) to (4) above may be combined depending on the usage status of the X-ray CT apparatus 1. For example, when the rotation speed of at least one of the cooling fans 17, 18, and 19 is to be reduced, the rotation speed may be reduced in accordance with the priority order.

[0062] After suppressing the operating noise, if the detection unit 41 detects that the distance between the subject S and the operator OP exceeds a certain value based on the image captured by the bed imaging unit 42, the fan control unit 45 returns the rotational operation of the cooling fans 17, 18, and 19 to the state during normal imaging, and ends the suppression of the operating noise of the X-ray CT device 1.

[0063] Instead of ending the suppression of the operating noise based on the distance between the subject S and the operator OP, the rotation of the cooling fans 17, 18, and 19 may be automatically returned to the normal state during imaging after a predetermined time has elapsed since the suppression of the operating noise began.

[0064] As described above, according to the first embodiment, it is detected that the subject S and the operator OP can have a conversation based on the image captured by the bed imaging unit 42, and the cooling fan is controlled to suppress the operating noise. This makes it possible to suppress the operating noise so that the operator OP and the subject S can have a good conversation while avoiding stopping the imaging operation of the X-ray CT apparatus 1.

[0065] <Modification 1 of the First Embodiment> In the first embodiment, the bed imaging unit 42 has an angle of view that can capture almost the entire bed 3 in its imaging range. On the other hand, in a modification of the first embodiment, the bed imaging unit 42 is disposed, for example, on the wall surface of the gantry 20, and has an imaging range that can capture an image of the face of the subject S placed on the bed 3. The bed imaging unit 42 captures images (sequential images or video) of the face of the subject S at predetermined time intervals (for example, every several tens of seconds) or continuously.

[0066] The detection unit 41 extracts the mouth movement of the subject S on the bed 3 based on the image captured by the bed imaging unit 42, and detects a conversation between the subject S and the operator OP based on the mouth movement. Specifically, for example, if the mouth moves continuously for a predetermined time or more, the detection unit 41 determines that a conversation between the subject S and the operator OP has been detected. Then, the detection unit 41 outputs the detection result to the fan control unit 45. The operation control of the cooling fans 17, 18, and 19 by the fan control unit 45 is the same as in the first embodiment, and therefore a description thereof will be omitted.

[0067] After suppressing the operation sounds, if the detection unit 41 is no longer able to extract mouth movement from the image captured by the bed imaging unit 42, the fan control unit 45 returns the rotational operation of the cooling fans 17, 18, and 19 to the normal imaging state, and ends the suppression of the operation sounds of the X-ray CT device 1. Note that the rotational operation of the cooling fans 17, 18, and 19 may be automatically returned to the normal imaging state after a predetermined time has elapsed since the suppression of the operation sounds began. Even in this modification, it is possible to suppress the operation sounds so that the operator OP and the subject S can have a good conversation while avoiding stopping the imaging operation of the X-ray CT device 1.

[0068] The modified example of the first embodiment can also be applied to a case where a conversation takes place between an operator OP in an operation room and a subject S in an imaging room, as in a third embodiment described later.

[0069] Second Embodiment 5 is a schematic configuration diagram of an X-ray CT apparatus 1 to which an operation noise suppression device 40 according to the second embodiment is applied. Preferably, the second embodiment is applied to a case where a conversation takes place between an operator OP and a subject S near a bed 3 in an imaging room, similar to the first embodiment. As shown in FIG. 5, the detection unit 41 includes a sound collection unit (first sound collection unit) 43 that collects sounds near the bed 3. For example, the sound collection unit 43 is disposed near the bed 3 on the outer surface of the housing of the gantry 20.

[0070] The detection unit 41 detects that the subject S and the operator OP are having a conversation when a frequency corresponding to a human voice is extracted from the sound collected by the sound collection unit 43. The detection unit 41 outputs the detection result to the fan control unit 45.

[0071] The operation of the fan control unit 45 is the same as in the first embodiment, and therefore description thereof will be omitted. After suppressing the operation noise, if the detection unit 41 can no longer extract a frequency corresponding to a human voice from the sound collected by the sound collection unit 44, the fan control unit 45 returns the rotational operation of the cooling fans 17, 18, and 19 to the state during normal imaging, and ends the suppression of the operation noise of the X-ray CT apparatus 1. Note that the rotational operation of the cooling fans 17, 18, and 19 may be automatically returned to the state during normal imaging after a predetermined time has elapsed since the suppression of the operation noise began. In the second embodiment, too, it is possible to suppress the operation noise so that the operator OP and the subject S can have a good conversation while avoiding stopping the imaging operation of the X-ray CT apparatus 1.

[0072] Third Embodiment In the first and second embodiments, suppression of operation noise when a conversation takes place between the operator OP and the subject S in the imaging room has been described. However, when imaging is performed using the X-ray CT apparatus 1, the operator OP in the operation unit 30 in the operation room may instruct the subject S in the imaging room to hold their breath or move their body, or may check whether they are feeling unwell. Preferably, the third embodiment is applied to a case where a conversation takes place between the operator OP in the operation room and the subject S in the imaging room.

[0073] Fig. 6 is a schematic configuration diagram of an X-ray CT apparatus 1 to which an operation noise suppression device 40 according to the third embodiment is applied. As shown in Fig. 6, the detection unit 41 includes a sound collection unit 44 (second sound collection unit) that collects sounds in the vicinity of the operation unit 30. For example, an existing microphone provided in the operation unit 30 for transmitting sound from the operation room to the imaging room may be used as the sound collection unit 44.

[0074] The detection unit 41 detects that the subject S and the operator OP are having a conversation when a frequency corresponding to a human voice is extracted from the sound collected by the sound collection unit 44. The detection unit 41 outputs the detection result to the fan control unit 45, and the fan control unit 45 controls at least one of the cooling fans 17, 18, and 19 to suppress the operating noise of the X-ray CT apparatus 1.

[0075] The sound collection unit 44 may include an operation switch (not shown) that instructs sound to be sent from the operation room to the imaging room. In this case, by detecting that the operation switch of the sound collection unit 44 has been turned on, the detection unit 41 may detect that sound can be sent from the operation room to the imaging room, that is, that the subject S and the operator OP can have a conversation.

[0076] Also, an automatic voice function (auto-voice function) provided in the X-ray CT apparatus 1 may be used to issue instructions to the subject S. In this case, by detecting that an announcement from the automatic voice function has started, the detection unit 41 may detect that it is possible to send voice from the operation room to the imaging room, that is, that the subject S and the operator OP are in a situation where they can talk to each other.

[0077] The operation of the fan control unit 45 is the same as in the first embodiment, and therefore will not be described. After suppressing the operating noise, if the detection unit 41 is no longer able to extract a frequency corresponding to a human voice from the sound collected by the sound collection unit 44, the fan control unit 45 returns the rotation of the cooling fans 17, 18, and 19 to the normal imaging state and ends the suppression of the operating noise of the X-ray CT system 1. If the operation switch of the sound collection unit 44 is turned off or if the announcement from the automatic voice function ends, the rotation of the cooling fans 17, 18, and 19 may be returned to the normal imaging state. After a predetermined time has elapsed since the start of the suppression of the operating noise, the rotation of the cooling fans 17, 18, and 19 may be automatically returned to the normal imaging state.

[0078] In the third embodiment, when a conversation takes place between an operator OP from the control room and a subject S in the imaging room, it is possible to suppress the operating noise so that the operator OP and the subject S can have a good conversation while avoiding stopping the imaging operation of the X-ray CT device 1.

[0079] <Modification of the third embodiment> In the third embodiment, a sound collection unit 44 is provided in the operation room. On the other hand, in a modified example of the third embodiment, an operation room imaging unit (not shown) is provided instead of the sound collection unit 44. For example, a display unit may be provided in the gantry 20 and an imaging unit may be provided in the operation room so that instructions from the operator OP in the operation room can be given to the subject S using video. Such an existing imaging unit may be used as the operation room imaging unit.

[0080] The detection unit 41 extracts the movement of the operator OP's mouth based on the image captured by the operation room imaging unit, and detects that the subject S and the operator OP are conversing if the mouth continues to move for a predetermined time or more. The detection unit 41 outputs the detection result to the fan control unit 45. The fan control unit 45 is the same as in the first embodiment and the modified example of the first embodiment, and therefore a description thereof will be omitted.

[0081] In this modification, it is possible to suppress the operating noise so that the operator OP and the subject S can have a good conversation while avoiding stopping the imaging operation of the X-ray CT apparatus 1.

[0082] <Other> The fan control unit 45 can be realized by various processors. The various processors include a CPU and / or a GPU (Graphic Processing Unit), which are general-purpose processors, a programmable logic device (PLD), such as an FPGA (Field Programmable Gate Array), which is a processor whose circuit configuration can be changed after manufacturing, and a dedicated electrical circuit, such as an ASIC (Application Specific Integrated Circuit), which is a processor having a circuit configuration designed specifically for executing specific processing.

[0083] The fan control unit 45 may be configured with one of these various processors, or may be configured with two or more processors of the same or different types. For example, the fan control unit 45 may be configured with multiple FPGAs, or a combination of a CPU and an FPGA.

[0084] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the first to third embodiments and their modifications may be combined as appropriate. [Explanation of symbols]

[0085] 1 X-ray CT device 17, 18, 19 Cooling fan 40 Operation noise suppression device 41 Detector 42 Bed imaging unit 43,44 Sound collection section 45 Fan control unit OP Operator S subject

Claims

1. An operation noise suppression device used in an X-ray tomography apparatus, a detection unit that detects whether a conversation is taking place or whether a conversation is possible between an operator of the X-ray tomography apparatus and a subject placed on a bed of the X-ray tomography apparatus; a fan control unit that controls the operation of one or more cooling fans provided in the X-ray tomography apparatus based on the detection result of the detection unit; An operation noise suppression device comprising:

2. the detection unit includes a bed imaging unit that captures an image of the vicinity of the bed, the detection unit detects a situation in which the operator and the subject can have a conversation based on a distance between the operator and the subject in an image captured by the bed imaging unit. The operation noise suppression device according to claim 1 .

3. the detection unit includes a first sound collection unit that collects sounds in the vicinity of the bed, the detection unit detects a conversation between the operator and the subject based on the sound collected by the first sound collection unit. The operation noise suppression device according to claim 1 .

4. the detection unit includes a second sound collection unit that collects sounds near an operation unit that operates imaging by the X-ray tomography apparatus, the detection unit detects a conversation between the operator and the subject based on the sound collected by the second sound collection unit. The operation noise suppression device according to claim 1 .

5. the fan control unit reduces the rotation speed of at least one of the one or more cooling fans based on the detection result by the detection unit. The operation noise suppression device according to claim 1 .

6. the fan control unit temporarily stops operation of at least one of the one or more cooling fans based on the detection result by the detection unit. The operation noise suppression device according to claim 1 .

7. one or more cooling fans; An operation noise suppression device according to any one of claims 1 to 6; An X-ray tomography apparatus comprising:

Images