CN112450908A

CN112450908A - Medical image diagnosis device and heartbeat measurement device

Info

Publication number: CN112450908A
Application number: CN202010907403.XA
Authority: CN
Inventors: 川上毅人; 富井翔一朗; 田平圭司
Original assignee: Canon Medical Systems Corp
Current assignee: Canon Medical Systems Corp
Priority date: 2019-09-06
Filing date: 2020-09-02
Publication date: 2021-03-09
Also published as: JP7270510B2; JP2021040757A

Abstract

A medical image diagnosis device and a heartbeat measurement device perform heartbeat measurement of a subject in a non-contact manner and with high accuracy. A medical image diagnostic apparatus according to an embodiment includes a measurement device and a mechanism unit. The measurement device images a subject placed on a top plate and outputs heartbeat information related to heartbeats. The mechanism unit changes the measurement position of the measurement device so that the relative position of the measurement device with respect to the top plate changes.

Description

Medical image diagnosis device and heartbeat measurement device

The present application claims the benefit of priority based on the japanese patent application No. 2019-163377 filed on 6.9.2019, the entire contents of which are incorporated herein by reference.

Technical Field

The embodiment relates to a medical image diagnosis device and a heartbeat measurement device.

Background

Conventionally, in a medical image diagnosis apparatus such as a Magnetic Resonance Imaging (MRI) apparatus, a medical image corresponding to a cardiac phase is captured based on an output of a sensor such as an electrocardiograph attached to a body of a subject.

In recent years, attempts have been made to detect heartbeats in a noncontact manner without mounting a sensor on the subject. For example, a technique for measuring heart beats from an image of a subject captured by a camera has been proposed. However, since a single camera whose position and imaging field of view are fixed cannot be adapted to the posture of the subject, there is a possibility that the heartbeat cannot be measured depending on the posture of the subject at the time of imaging.

Disclosure of Invention

The present invention addresses the problem of providing a medical image diagnostic apparatus and a heartbeat measuring apparatus that can perform heartbeat measurement of a subject in a non-contact manner and with high accuracy.

A medical image diagnostic apparatus according to an embodiment includes a measurement device and a mechanism unit. The measurement device images a subject placed on a top plate and outputs heartbeat information related to heartbeats. The mechanism unit changes the measurement position of the measurement device so that the relative position of the measurement device with respect to the top plate changes.

Effects of the invention

According to the medical image diagnostic apparatus and the heartbeat measuring apparatus of the embodiment, the heartbeat of the subject can be measured in a non-contact manner and with high accuracy.

Drawings

Fig. 1 is a perspective view showing an example of an external configuration of a magnetic resonance imaging apparatus according to embodiment 1.

Fig. 2 is a diagram showing a state of the inside of the cavity as viewed from the front side of the gantry according to embodiment 1.

Fig. 3 is a view showing a state in the bore on the-X axis direction side as viewed from the a-a section of fig. 2.

Fig. 4 is a diagram for explaining an example of a mounting structure of the measurement device and the support arm according to embodiment 1.

Fig. 5 is a diagram showing an example of the configuration of the magnetic resonance imaging apparatus according to embodiment 1.

Fig. 6 is a diagram for explaining the relationship between the heartbeat signal and the threshold value according to embodiment 1.

Fig. 7 is a flowchart showing an example of MR imaging processing performed by the processing circuit of embodiment 1.

Fig. 8 is a diagram for explaining the mounting position of the measurement device according to modification 1 of embodiment 1.

Fig. 9 is a diagram for explaining the relationship between the heartbeat signal and the threshold value according to modification 3 of embodiment 1.

Fig. 10 is a perspective view showing an example of the mobile screen device according to modification 4 of embodiment 1.

Fig. 11 is a front view of the mobile screen device shown in fig. 10.

Fig. 12 is a side view of the mobile screen apparatus shown in fig. 10.

Fig. 13 is a perspective view showing a state in which the portable screen device according to modification 4 of embodiment 1 is coupled to a top plate.

Fig. 14 is a view showing a state inside the cavity as viewed from the front side of the gantry according to embodiment 2.

Fig. 15 is a view showing a state in the bore 20a on the-X axis direction side as viewed from the a-a section of fig. 14.

Fig. 16 is a flowchart showing an example of MR imaging processing performed by the processing circuit of embodiment 2.

Fig. 17 is a diagram for explaining the mounting position of the measurement device according to modification 1 of embodiment 2.

Fig. 18 is a diagram showing a state inside the cavity as viewed from the front side of the gantry according to variation 2 of embodiment 2.

Fig. 19 is a view showing a state in the bore on the-X axis direction side as viewed from the a-a section of fig. 18.

Detailed Description

Hereinafter, embodiments of a medical image diagnostic apparatus and an imaging apparatus according to the embodiments will be described with reference to the drawings. In the embodiments described below, an example of the medical image diagnostic apparatus applied to a Magnetic Resonance Imaging (MRI) apparatus will be described as an example.

[ embodiment 1 ]

Fig. 1 is a perspective view showing an example of an external configuration of a magnetic resonance imaging apparatus according to embodiment 1. A magnetic resonance imaging apparatus 1 shown in fig. 1 is an example of a medical image diagnostic apparatus. As shown in fig. 1, the magnetic resonance imaging apparatus 1 has a bed 10 and a gantry 20.

The couch 10 is disposed outside the gantry 20. The bed 10 includes: a top plate 10a on which the subject P is placed; and a base portion 10b supporting the top plate 10a from below.

The base portion 10b can move the top plate 10a in the vertical direction. The base unit 10b can move the top plate 10a in the horizontal direction so as to feed the top plate 10 into the cavity 20a provided in the gantry 20 or to take out the top plate 10a from the cavity 20 a.

The gantry 20 has a hollow bore 20a formed in a substantially cylindrical shape (a shape including a cross section perpendicular to the central axis and an elliptical shape), and houses a static field magnet 21, a gradient coil 22, a transmission coil 23, and the like, which will be described later. Here, the space in the bore 20a is an imaging space for imaging the subject P.

The X axis, the Y axis, and the Z axis mean a device coordinate system unique to the magnetic resonance imaging device 1. For example, the Z axis is set along the magnetic flux of the static magnetic field generated by the static field magnet 21. The X axis is set along a horizontal direction orthogonal to the Z axis, and the Y axis is set along a vertical direction orthogonal to the Z axis.

The gantry 20 is provided with a measurement device 30 and an illumination device 50 for heartbeat measurement of the subject P. The measurement device 30 and the illumination device 50 will be explained below.

Fig. 2 and 3 are views for explaining the measuring device 30 and the illumination device 50 provided in the gantry 20. Here, fig. 2 is a view showing a state in the bore 20a as viewed from the bed 10 side (front side) of the gantry 20. Fig. 3 is a view showing a state in the bore 20a on the-X axis direction side as viewed from the a-a cross section of fig. 2. Hereinafter, the side of the bore 20a on which the bed 10 is provided is also referred to as "front side", and the opposite side is also referred to as "rear side".

The measurement device 30 is provided in the gantry 20 at a position where the subject P placed on the top plate 10a can be measured (imaged). For example, the measurement device 30 is provided in the bore 20a of the gantry 20, or is provided on an end surface of the gantry 20 near an opening of the bore 20 a.

Fig. 2 and 3 show an example in which the measurement device 30 is disposed in the bore 20a of the gantry 20. Specifically, the measurement device 30 is supported by a support arm 40 provided in the bore 20 a.

The measuring device 30 includes an imaging unit 31 such as a color camera or an infrared camera. The measurement device 30 images the subject P placed on the top plate 10a, and outputs information related to cardiac activity (hereinafter referred to as cardiac activity information) from an image (video) of the subject P obtained by the imaging. That is, the measurement device 30 acquires heartbeat information from the subject P so as not to contact the subject P.

Here, the heartbeat information may be an image itself obtained by imaging or a heartbeat signal representing a heartbeat extracted from the image. In the latter case, the method of extracting the signal is not particularly limited, and a known technique can be used. For example, the measurement device 30 may extract a heartbeat signal by image analysis of reflected light on the skin surface accompanying contraction and expansion of blood vessels. The measurement device 30 is configured not to affect the magnetic field or to be hardly affected by the magnetic field. For example, the measuring device 30 is made of a nonmagnetic material that is not affected by a magnetic field.

The support arm 40 is an example of a mechanism portion. The support arm 40 has, for example, a curved shape corresponding to the shape of the chamber 20 a. Here, on the inner wall (inner periphery) 40a side of the support arm 40, a1 st moving mechanism 41 such as a groove or a rail is provided in the circumferential direction of the support arm 40. The measuring device 30 can be moved in the circumferential direction of the support arm 40, that is, around the long axis (the direction of arrow a 1) of the top plate 10a by being attached to the 1 st moving mechanism 41.

The structure of the 1 st moving mechanism 41 and the structure of mounting the measuring device 30 to the 1 st moving mechanism 41 are not particularly limited, and various modes can be adopted. For example, in the case where the 1 st moving mechanism 41 is configured by a groove, a rail, or the like, the mounting of the measuring device 30 to the 1 st moving mechanism 41 may be configured as shown in fig. 4. The support arm 40 is configured not to be affected by a magnetic field or to be hardly affected by a magnetic field. For example, the support arm 40 is made of a nonmagnetic material such as resin that is not affected by a magnetic field.

Fig. 4 is a diagram for explaining an example of the mounting structure of the measurement device 30 and the support arm 40. As shown in fig. 4, a groove 41a having a substantially T-shaped cross section is provided in the circumferential direction of the support arm 40 as the 1 st moving mechanism 41 on the inner wall 40a side of the support arm 40.

On the other hand, the measuring device 30 includes a substantially T-shaped engaging portion 32 corresponding to the cross-sectional shape of the 1 st moving mechanism 41 in a part of the housing. The measuring device 30 is attached so that the engaging portion 32 engages with the groove portion 41a of the 1 st moving mechanism 41. Here, a predetermined gap is provided between the engagement portion 32 and the groove portion 41a, and the engagement portion 32 is movable along the groove portion 41 a. In addition, in the contact portion between the engagement portion 32 and the groove portion 41a, for example, a wheel or a low friction material may be provided in order to improve the slidability of the measurement device 30.

The 1 st moving mechanism 41 is not limited to the structure shown in fig. 4. For example, the 1 st movement mechanism 41 may include a driving device such as a conveyor belt or a motor that allows the measurement device 30 to move along the groove portion 41 a. In the present embodiment, a mode in which the movement of the measurement device 30 on the groove portion 41a is performed manually will be described.

Returning to fig. 2 and 3, the support arm 40 is movable in the Z-axis direction within the bore 20a of the gantry 20. Specifically, the support arm 40 is attached to a2 nd moving mechanism 42 provided on an inner wall of the chamber 20a and guiding movement in the Z-axis direction, and is movable in the Z-axis direction, that is, the longitudinal direction (a 2 direction in the drawing) of the top plate 10 a.

Fig. 2 and 3 show an example in which a pair of left and right rails 42a is provided as an example of the 2 nd moving mechanism 42. Here, the rail 42a is provided at a position not interfering with the movement of the top plate 10a into the cavity 20a and extending from the front side to the rear side of the gantry 20. Further, wheels or the like may be provided at the base of the support arm 40 facing the rail 42a to improve slidability.

The form of the 2 nd moving mechanism 42 is not limited to the above example, and may be realized by another form. For example, the following configuration may be adopted: the 2 nd moving mechanism 42 has a groove portion similar to the 1 st moving mechanism 41 in place of the rail 42a, and moves the support arm 40 in the Z-axis direction by engagement of the groove portion with engagement portions provided at both ends of the support arm 40. For example, the 2 nd moving mechanism 42 may include a driving device such as a conveyor belt or a motor that can move the support arm 40 along the rail 42 a. In the present embodiment, a mode in which the support arm 40 is manually moved on the rail 42a will be described.

The support arm 40 can change the measurement position of the measurement device 30 by the above-described configuration, so that the relative position of the measurement device 30 with respect to the top plate 10a changes. Specifically, by changing the position of the measuring device 30 in the 1 st movement mechanism 41 (groove 41a) and the position of the support arm 40 in the 2 nd movement mechanism 42 (rail 42a), the position around the long axis of the top plate 10a and the position in the long axis direction can be changed independently.

The mount 20 is provided with an illumination device 50. The illumination device 50 is provided in the gantry 20 at a position where it can illuminate the subject P placed on the top plate 10 a. For example, the illumination device 50 is provided in the cavity 20a of the gantry 20 or on the end surface of the gantry 20 near the opening communicating with the cavity 20 a.

Fig. 2 and 3 show an example in which the measurement device 30 is disposed in the bore 20 a. In the above structure, an example in which the illumination device 50 is attached to the inner wall of the chamber 20a is shown.

The illumination device 50 illuminates the subject P mounted on the top plate 10 a. More specifically, the illumination device 50 illuminates the subject P to provide brightness required for measurement (imaging) of the subject P by the measurement device 30.

In fig. 2 and 3, the lighting devices 50 are provided at respective positions on the rear side of the inner wall of the chamber 20a and symmetrically in the left-right direction, but the positions or the number of the lighting devices 50 are not limited thereto. For example, the measurement device 30 and the illumination device 50 may be integrated so as to be movable by the support arm 40. According to the above configuration, the range imaged by the measurement device 30 can be illuminated by the illumination device 50 so as to be positioned (pinpoint), and therefore the subject P can be illuminated efficiently.

The illumination device 50 is configured not to affect a magnetic field or to be hardly affected by a magnetic field. For example, the illumination device 50 is formed using a non-magnetic material that is not affected by a magnetic field.

Next, the configuration of the magnetic resonance imaging apparatus 1 will be described with reference to fig. 5. Fig. 5 is a diagram showing an example of the configuration of the magnetic resonance imaging apparatus 1.

As shown in fig. 5, the magnetic resonance imaging apparatus 1 includes the bed 10 and the gantry 20, as well as the gradient magnetic field power supply 2, the transmission circuit 3, the reception circuit 4, the interface circuit 5, the input interface 6, the display 7, the storage circuit 8, the processing circuits 61 to 64, and the like.

The gantry 20 includes the measurement device 30, the support arm 40, and the illumination device 50 in the bore 20 a. The gantry 20 houses a static field magnet 21, a gradient coil 22, a transmission coil 23, a reception coil 24, and the like.

The static field magnet 21 generates a static magnetic field in a bore 20a in which the subject P is disposed. Specifically, the static magnetic field magnet 21 is formed in a hollow substantially cylindrical shape (including an elliptical shape in a cross section perpendicular to the central axis of the cylinder) so as to surround the bore 20a, and generates a static magnetic field in the space inside the cylinder. For example, the static field magnet 21 may be a superconducting magnet or a permanent magnet.

The gradient coil 22 is disposed inside the static field magnet 21 and applies a gradient magnetic field to the bore 20a in which the subject P is disposed. Specifically, the gradient magnetic field coil 22 generates a gradient magnetic field along each of the X, Y, and Z axes.

The transmission coil 23 is disposed inside the gradient coil 22, and applies an RF magnetic field to the inside of the bore 20a (imaging space) in which the subject P is disposed, based on an RF (radio frequency) pulse input from the transmission circuit 3.

The receiving coil 24 receives an NMR (Nuclear Magnetic Resonance) signal generated from the subject P due to the influence of the RF Magnetic field applied by the transmitting coil 23, and outputs the NMR signal as an MR (Magnetic Resonance) signal to the receiving circuit 4.

The static magnetic field magnet 21 or the gradient magnetic field coil 22, and the transmission coil 23 or the reception coil 24 provided in the gantry 20 are examples of an imaging unit related to acquisition of a medical image of the subject P.

In fig. 5, the receiving coil 24 is provided independently of the transmitting coil 23, but this is merely an example and is not limited to this configuration. For example, the reception coil 24 and the transmission coil 23 may be used in combination. The receiving coil 24 is not limited to a receiving coil for the whole body provided in the gantry, and may be a local coil corresponding to the imaging target region. Examples of the local coil include a coil for imaging a spine and a coil for imaging a head. When there are a plurality of imaging target portions, a plurality of local coils may be provided as the reception coils 24.

The gradient magnetic field power supply 2 supplies a current to the gradient magnetic field coil 22, thereby generating a gradient magnetic field along each of the X, Y, and Z axes in the space inside the gradient magnetic field coil 22.

The transmission circuit 3 supplies an RF pulse corresponding to a larmor frequency determined by the type of the target nucleus and the intensity of the magnetic field to the transmission coil 23.

The receiving circuit 4 generates MR data based on the MR signals output from the receiving coil 24, and outputs the generated MR data to the processing circuit 62. For example, the receiving circuit 4 includes a selection circuit, a preamplifier circuit, a phase detector circuit, and an analog-to-digital conversion circuit. The selection circuit selectively inputs the MR signal output from the reception coil 24. The preamplification circuit amplifies the MR signal output from the selection circuit. The phase detection circuit detects the phase of the MR signal output from the preamplifier circuit. The analog-to-digital conversion circuit generates MR data by converting the analog signal output from the phase detection circuit into a digital signal, and outputs the generated MR data to the processing circuit 62. The receiving coil 24 may have a configuration in which the MR signal converted into the digital signal is output to the processing circuit 62 as MR data by having a part of the functions of the receiving circuit 4 described above.

The interface circuit 5 is connected to each of the measurement device 30, the support arm 40, and the illumination device 50, and relays communication between each of the devices and the processing circuit 64. For example, the interface circuit 5 outputs heartbeat information input from the measurement device 30 to the processing circuit 64. For example, the interface circuit 5 outputs control information related to the drive control of the 1 st movement mechanism 41 and the 2 nd movement mechanism 42, which is input from the measurement device 30, to the 1 st movement mechanism 41 and the 2 nd movement mechanism 42 of the support arm 40. For example, the interface circuit 5 outputs control information related to illuminance control of the lighting device 50, which is input from the measurement device 30, to the lighting device 50.

The input interface 6 receives various instructions and input operations of various information from an operator. Specifically, the input interface 6 is connected to each processing circuit, converts an input operation received from an operator into an electric signal, and outputs the electric signal to the control circuit. For example, the input interface 6 is implemented by a trackball, a switch button, a mouse, a keyboard, a touch panel that performs an input operation by touching an operation surface, a touch panel that integrates a display screen and a touch panel, a non-contact input interface using an optical sensor, an audio input interface, and the like. The input interface 6 is not limited to a device including a physical operation member such as a mouse or a keyboard. For example, a processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the apparatus and outputs the electric signal to the control circuit is also included in the input interface 6.

The display 7 displays various information and various images. Specifically, the display 7 is connected to each processing circuit, and converts various information and various image data sent from the processing circuit into electric signals for display and outputs the electric signals. For example, the display 7 is implemented by a liquid crystal display (lcd), a crt (cathode Ray tube) display, a touch panel, or the like.

The storage circuit 8 stores various data. Specifically, the storage circuit 8 stores MR data or image data. For example, the memory circuit 8 is implemented by a semiconductor memory element such as a ram (random Access memory) or a flash memory, a hard disk, an optical disk, or the like.

The processing circuit 61 has a couch control function 61 a. The bed control function 61a controls the operation of the bed 10 by outputting control electric signals to the bed 10. For example, the bed control function 61a receives an instruction to move the top plate 10a in the longitudinal direction, the vertical direction, or the horizontal direction from the operator via the input interface 6, and operates the moving mechanism of the top plate 10a included in the bed 10 so as to move the top plate 10a in accordance with the received instruction.

The processing circuit 62 has an execution function 62 a. The execution function 62a executes various pulse sequences by driving the gradient magnetic field power supply 2, the transmission circuit 3, and the reception circuit 4 based on the sequence execution data output from the processing circuit 64. For example, the execution function 62a drives the gradient magnetic field power supply 2, the transmission circuit 3, and the reception circuit 4 by transmitting input signals to the gradient magnetic field power supply 2, the transmission circuit 3, and the reception circuit 4, respectively.

Here, the sequence execution data is information defining a pulse sequence representing the order for collecting MR data. Specifically, the sequence execution data is information defining the timing at which the gradient magnetic field power supply 2 supplies a current to the gradient magnetic field coil 22, the intensity or supply timing of the supplied current, the intensity or supply timing of the RF pulse signal supplied from the transmission circuit 3 to the transmission coil 23, the detection timing at which the reception circuit 4 detects the MR signal, and the like.

Further, the execution function 62a receives MR data from the reception circuit 4 as a result of executing various pulse sequences, and stores the received MR data in the storage circuit 8. The set of MR data received by the execution function 62a is arranged in accordance with the phase encode amount given by the gradient magnetic field and the frequency encode amount at the time of reading, and is stored in the storage circuit 8 as data constituting the k-space.

The processing circuit 63 has an image generating function 63 a. The image generating function 63a generates an image based on the MR data stored in the storage circuit 8. Specifically, the image generating function 63a reads the k-space data stored in the storage circuit 8 by the execution function 62a, and generates an image by performing reconstruction processing such as fourier transform on the read k-space data. The image generation function 63a causes the storage circuit 8 to store the image data of the generated image. In the present specification, a series of processes related to the generation of image data by the processing circuit 62 (execution function 62a) and the processing circuit 63 (image generation function 63a) will be referred to as "imaging" or "MR imaging".

The processing circuit 64 has a measurement control function 64a, a heartbeat detection function 64b, a light control function 64c, and an imaging function 64 d.

The measurement control function 64a is an example of a measurement control unit. The measurement control function 64a controls the operation of the measurement device 30 and the lighting device 50 by outputting various control signals to the measurement device 30, the support arm 40, and the lighting device 50 via the interface circuit 5. Specifically, the measurement control function 64a starts heartbeat measurement of the subject P placed on the top board 10a by driving the measurement device 30 and the illumination device 50.

The heartbeat detecting function 64b detects heartbeats of the subject P placed on the top board 10a based on heartbeat information measured by the measuring device 30. Specifically, the measurement control function 64a analyzes heartbeat information (image) input from the measurement device 30 via the input interface 6, and extracts a heartbeat signal indicating the heartbeat of the subject P. Further, the heartbeat detecting function 64b detects the cardiac time equality of the subject P based on the extracted heartbeat signal.

In the case of the configuration in which the heartbeat signal is output from the measurement device 30, the heartbeat detection function 64b detects the cardiac time of the subject P based on the heartbeat signal input from the measurement device 30.

The dimming function 64c is an example of the adjustment unit. The dimming function 64c controls the operation of the lighting device 50. Specifically, the light control function 64c adjusts the illuminance of the lighting device 50 in accordance with the state of the heartbeat information or the heartbeat signal in cooperation with the heartbeat detection function 64 b.

For example, regarding the dimming function 64c, as shown in (a) of fig. 6, it is assumed that the signal level of the heart beat signal PL detected by the heart beat detection function 64b is smaller than the predetermined threshold value TH. Here, fig. 6 is a diagram for explaining the relationship between the heartbeat signal PL and the threshold value TH. The threshold TH is an index value for the heartbeat detection function 64b to determine each cardiac phase from the heartbeat signal PL. The signal level of the heartbeat signal PL means a signal value for clearly identifying a maximum value of the heartbeat signal PL or a specific cardiac phase.

However, the signal level of the heartbeat signal detected by the heartbeat detection function 64b is derived from an image measured (captured) by the measurement device 30, and is therefore affected by ambient light. Therefore, for example, when the brightness of the imaging range of the measurement device 30 does not satisfy a predetermined reference, as shown in fig. 6 (a), the signal level of the heartbeat signal PL may not reach the threshold TH.

Therefore, in the dimming function 64c, when the signal level of the heartbeat signal PL is less than the threshold TH, the illuminance of the lighting device 50 is increased until the signal level of the heartbeat signal PL becomes equal to or greater than the threshold TH as shown in fig. 6 (b). By increasing the illuminance of the lighting device 50 in this way, the signal level of the heartbeat signal can be increased. Thus, the heartbeat detecting function 64b can detect heartbeats (cardiac phase phases and the like) of the subject P based on the measurement information acquired by the measuring apparatus 30.

The dimming function 64c may be controlled to decrease the illuminance as well as increase the illuminance of the lighting device 50. For example, when the minimum value of the signal level of the cardiac signal PL exceeds the threshold TH, the dimming function 64c may decrease the illuminance of the lighting device 50 until each cardiac phase can be determined.

The photographing function 64d performs control related to MR photographing. For example, the imaging function 64d receives an input of imaging conditions from the operator via the input interface 6. The imaging function 64d generates sequence execution data based on the received imaging conditions, and transmits the sequence execution data to the processing circuit 62, thereby executing various pulse sequences.

Then, for example, the measurement control function 64a performs MR imaging in synchronization with the heartbeat signal detected by the heartbeat detection function 64b in response to a request from the operator. Specifically, the measurement control function 64a performs MR imaging at the timing of a specific cardiac phase such as the diastole or the systole.

For example, each of the processing circuits described above is realized by a processor. In this case, for example, the processing functions of the processing circuits are stored in the storage circuit 8 in the form of programs that can be executed by a computer. Each processing circuit realizes a function corresponding to each program by reading each program from the storage circuit 8 and executing it. In other words, each processing circuit in which the state after each program is read has each function shown in each processing circuit of fig. 5.

Each processing circuit may be configured by combining a plurality of independent processors, and each processor may execute a program to realize each function. Further, the functions of the respective processing circuits may be implemented by being distributed or integrated as appropriate to a single or a plurality of processing circuits. The functions of the processing circuits may be realized by a mixture of hardware such as a circuit and software.

The term "processor" used in the above description means, for example, a cpu (central Processing unit), a gpu (graphics Processing unit), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (e.g., a Simple Programmable Logic Device (SPLD)), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). The processor realizes its function by reading and executing a program stored in the storage circuit 8. Instead of storing the program in the storage circuit 8, the program may be directly written in the circuit of the processor. In this case, the processor realizes its function by reading and executing a program written in the circuit. The processor of the present embodiment is not limited to a single circuit configuration, and may be configured by combining a plurality of independent circuits to implement the functions of one processor.

Here, the program executed by the processor is written in advance in a rom (read Only memory), a memory circuit, or the like and provided. The program may be recorded in a computer-readable storage medium such as CD (compact Disk) -ROM, FD (Flexible Disk), CD-r (recordable), dvd (digital Versatile Disk), or the like in a file that can be installed in the apparatus or executed. The program may be stored in a computer connected to a network such as the internet, and may be provided or distributed by being downloaded via the network. For example, the program is constituted by modules including the above-described functional units. As actual hardware, the CPU reads and executes a program from a storage medium such as a ROM, and the modules are loaded onto a main storage device and generated on the main storage device.

Next, an operation example of the magnetic resonance imaging apparatus 1 according to the present embodiment will be described with reference to fig. 7. Fig. 7 is a flowchart showing an example of the operation of the magnetic resonance imaging apparatus 1 according to the present embodiment.

First, a healthcare worker such as an operator of the magnetic resonance imaging apparatus 1 manually operates the 1 st movement mechanism 41 and the 2 nd movement mechanism 42 to move the measurement device 30 to a measurement position corresponding to the posture of the subject P (step S11). The measurement position means a position of the measurement device 30 when measuring the heartbeat of the subject P placed on the top board 10 a.

In step S11, the healthcare practitioner positions the measurement device 30 at a measurement position where the face or neck of the subject P can be imaged, for example. Since the face or the neck is a region where the skin is exposed, the measurement device 30 can easily obtain an image or video required for acquiring heartbeat information.

After the measurement device 30 moves, the measurement control function 64a operates the measurement device 30 and the illumination device 50 in accordance with an operation or the like via the input interface 6, and starts heartbeat measurement of the subject P. Next, the dimming function 64c determines whether or not the signal level of the heartbeat signal detected by the heartbeat detection function 64b is equal to or higher than a threshold value (step S12). Here, when the signal level of the heartbeat signal is less than the threshold value (step S12; no), the dimming function 64c increases the illuminance of the lighting device 50 by a predetermined amount (step S13), and the process returns to step S12. In addition, for example, in the case where the minimum value of the signal level exceeds the threshold value, the dimming function 64c may decrease the illuminance of the lighting device 50 by a predetermined amount in step S13.

On the other hand, when the signal level of the heartbeat signal is equal to or higher than the threshold value (step S12; YES), the process proceeds to step S14. Next, the imaging function 64d performs MR imaging of the subject P at the timing of a predetermined cardiac phase based on the cardiac signal detected by the cardiac beat detection function 64b (step S14). Further, only the heartbeat signal may be acquired (recorded) in advance. For example, in the case of MR imaging using a retrospective gating method, MR data can be reconstructed based on previously acquired cardiac beat signals (cardiac phase information).

As described above, the magnetic resonance imaging apparatus 1 of the present embodiment includes: a measurement device 30 that images a subject P placed on the top plate 10a and outputs heartbeat information relating to heartbeats; and a support arm 40 (a 1 st moving mechanism 41, a2 nd moving mechanism 42) that changes the measurement position of the measurement device 30 so that the relative position of the measurement device 30 with respect to the top plate 10a changes. Further, in the magnetic resonance imaging apparatus 1, the measurement device 30 can be moved according to the position of the top plate 10a, the posture of the subject P placed on the top plate 10a, or the like by manually operating the 1 st movement mechanism 41 or the 2 nd movement mechanism 42.

Thus, the magnetic resonance imaging apparatus 1 can position the measurement device 30 at the measurement position corresponding to the position of the top plate 10a or the posture of the subject P, and therefore can perform heartbeat measurement of the subject P under appropriate conditions. Therefore, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

The magnetic resonance imaging apparatus 1 adjusts the illuminance of the illumination device 50 in accordance with the state of the heartbeat information (heartbeat signal) output from the measurement device 30. This enables the magnetic resonance imaging apparatus 1 to ensure the illuminance necessary for heartbeat measurement, thereby improving the measurement accuracy.

The above-described embodiment can also be implemented by appropriately modifying a part of the structure or function of the magnetic resonance imaging apparatus 1. Therefore, several modifications of the above-described embodiment will be described as other embodiments below. In the following description, differences from the above-described embodiments will be mainly described, and detailed description of common points with those already described will be omitted. The modifications described below may be implemented independently, or may be implemented in combination as appropriate.

(modification 1)

In the above-described embodiment, the measurement device 30 is configured to be movable both around the longitudinal axis of the top plate 10a and in the longitudinal direction, but may be configured to be movable only in one direction.

For example, the measurement device 30 may be formed to be movable only around the longitudinal axis of the top plate 10 a. In this case, the measuring device 30 may be directly attached to the 1 st moving mechanism 41 (groove 41a) provided on the inner wall of the chamber 20a or the end surface of the mount 20, without passing through the support arm 40. In addition, when this configuration is adopted, the 1 st movement mechanism 41 is preferably provided at a position where the subject P can be efficiently imaged, such as on the rear side of the opening of the bore 20 a.

Fig. 8 is a diagram for explaining the mounting position of the measurement device 30 according to the present modification. Here, fig. 8 is a view of the mount 20 viewed from the rear side.

As shown in fig. 8, the measuring device 30 is provided on the end face 20b of the mount 20. Specifically, the measuring device 30 is attached in a state of being engaged with the 1 st moving mechanism 41 (groove 41a) provided on the end surface 20b of the mount 20. Here, the end surface 20b corresponds to a wall surface of the mount 20 near the opening of the bore 20a or a connection surface connecting the wall surface of the mount 20 and the bore 20 a.

The 1 st moving mechanism 41 has a curved shape corresponding to the opening shape of the bore 20 a. The measuring device 30 is attached to the 1 st moving mechanism 41 and is movable about the longitudinal axis (a 1 direction in the drawing) of the top plate 10 a.

An illumination device 50 is provided on the end face 20b of the mount 20. Fig. 8 shows an example in which a pair of illumination devices 50 are provided so as to face each other with a cavity 20a interposed therebetween. The illumination device 50 illuminates the top plate 10a to illuminate the imaging range of the measurement device 30.

Thus, the magnetic resonance imaging apparatus 1 according to the present modification can position the measurement device 30 at the position of the top plate 10a or at the measurement position corresponding to the posture of the subject P, as in the above-described embodiment, and therefore can perform heartbeat measurement of the subject P under appropriate conditions. Therefore, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

The illumination device 50 may be any device as long as it can illuminate the imaging range of the measurement device 30, and the installation position or number thereof is not limited to the example of fig. 8. For example, the illumination device 50 may be configured to be movable together with the measurement device 30 by being integrated with the measurement device 30.

Further, fig. 8 shows an example in which the measurement device 30 and the illumination device 50 are provided on the rear end face 20b of the gantry 20, but the present invention is not limited to this, and the measurement device 30 and the illumination device 50 may be provided on the front end face 20b of the gantry 20.

(modification 2)

In the above-described embodiment, a mode in which the measurement device 30 is manually moved is described. In the present modification, a mode in which the measurement device 30 is automatically moved will be described.

The following description will be given taking as an example the configuration of the magnetic resonance imaging apparatus 1 described with reference to fig. 2 and 3. It is assumed as a premise of the present modification that the 1 st moving mechanism 41 includes a driving device such as a conveyor belt or a motor that can move the measurement device 30 along the groove portion 41 a. It is assumed that the 2 nd moving mechanism 42 includes a driving device such as a conveyor belt or a motor that can move the support arm 40 along the rail 42 a. The 1 st movement mechanism 41 and the 2 nd movement mechanism 42 are configured to be driven under the control of the measurement control function 64 a.

The measurement control function 64a has a function of adjusting the position of the measurement device 30 with respect to the top plate 10a in addition to the functions described in the above-described embodiments. Specifically, the measurement control function 64a controls the position (measurement position) of the measurement device 30 when measuring the heartbeat of the subject P placed on the top board 10a by outputting a drive signal to the 1 st movement mechanism 41 and the 2 nd movement mechanism 42 via the interface circuit 5.

For example, when positional information indicating the position of the top plate 10a in the cavity 20a is input to the measurement control function 64a via the input interface 6, the measurement device 30 (the support arm 40) is moved to a measurement position corresponding to the positional information.

For example, when information indicating the posture of the subject P placed on the top board 10a is input via the input interface 6, the measurement control function 64a moves the measurement device 30 to a measurement position corresponding to the posture of the subject P. The measurement control function 64a derives the posture of the subject P based on, for example, any one of the right lateral decubitus, left lateral decubitus, supine decubitus, and prone decubitus, and one of the head and the feet is first introduced into the cavity 20 a. When the imaging method or sequence information corresponding to the posture of the subject P at the time of MR imaging includes information on the posture of the subject P, the posture of the subject P can be derived from the imaging method or sequence information.

Here, the measurement control function 64a sets, for example, a position at which the face or the neck of the subject P can be imaged as a measurement position. As described above, since the face or the neck is a region where the skin is exposed to a large extent, the measurement device 30 can easily obtain an image or video required for acquiring heartbeat information. For example, the measurement control function 64a specifies the measurement position in the longitudinal direction of the top board 10a based on the position in the Z-axis direction determined based on the position information of the top board 10a, and moves the measurement device 30 to the measurement position by the 2 nd movement mechanism 42. The measurement control function 64a specifies the measurement position around the longitudinal axis of the top plate 10a, and moves the measurement device 30 to the measurement position by the 1 st movement mechanism 41. The measurement control function 64a may also position the measurement device 30 at a position facing the face or neck of the subject P by detecting a characteristic part of the face of the subject P from the image captured by the measurement device 30. The facial features are, for example, organs such as eyes, nose, mouth, etc.

In this way, the measurement control function 64a specifies a measurement position at which the face, neck, or the like of the subject P can be imaged, based on the position of the top plate 10a, the posture of the subject P, or the like, and moves the measurement device 30 to the measurement position. This enables the measurement device 30 to perform measurement at a measurement position suitable for acquiring heartbeat information, and thus can improve measurement accuracy.

In the above example, the measurement control function 64a is configured to specify the measurement position, but the present invention is not limited thereto, and the measurement position may be directly instructed from the operator. Specifically, when the measurement position is instructed via the input interface 6, the measurement control function 64a drives the 1 st movement mechanism 41 and the 2 nd movement mechanism 42 to move the measurement device 30 to the instructed measurement position.

When the measurement device 30 and the illumination device 50 are integrated, the measurement control function 64a can control the position of the illumination device 50 with respect to the top plate 10a (subject P) by controlling the position of the measurement device 30.

Thus, the magnetic resonance imaging apparatus 1 according to the present modification can position the measurement device 30 at the measurement position corresponding to the position of the top plate 10a or the posture of the subject P, and therefore can perform heartbeat measurement of the subject P under appropriate conditions. Therefore, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

(modification 3)

In the above-described embodiment, a description has been given of a mode in which when the signal level of the heartbeat signal is less than the threshold value, the heartbeat signal is increased to be equal to or more than the threshold value by increasing the illuminance of the illumination device 50. However, the present invention is not limited to this embodiment. Therefore, in the present modification, another method of handling when the signal level of the heartbeat signal is less than the threshold value will be described.

First, the method of the first countermeasure 1 will be explained. In the method of the first countermeasure 1, a mode of adjusting the sensitivity (ISO sensitivity) of the measurement device 30 will be described. In the present modification, the measurement control function 64a functions as an example of an adjustment unit.

The measurement control function 64a of the present modification cooperates with the heartbeat detection function 64b to adjust the sensitivity of the measurement device 30 based on the state of heartbeat information or heartbeat signals.

For example, when the signal level of the heartbeat signal PL detected by the heartbeat detecting function 64b is less than the threshold TH, the sensitivity of the imaging unit 31 included in the measuring device 30 is increased until the signal level of the heartbeat signal PL becomes equal to or greater than the threshold TH. This increases the amount of light received by the imaging unit 31, and therefore, the same effect as that in the case of increasing the illuminance of the illumination device 50 can be obtained.

Next, the method of dealing with the item 2 will be described. In the method of the second countermeasure 2, a mode of adjusting the value of the threshold TH will be described. In the present modification, the heartbeat detecting function 64b functions as an example of the adjusting unit.

For example, assume the following: when the signal level of the heartbeat signal PL is less than the threshold TH, the signal level of the heartbeat signal does not reach the threshold even if the illuminance of the illumination device 50 is increased to the maximum by the above-described method. Further, the following is assumed: even if the sensitivity of the measurement device 30 is increased to the maximum, the signal level of the heartbeat signal does not reach the threshold value.

In this case, the heartbeat detecting function 64b lowers the threshold value TH to a position at which the signal level of the heartbeat signal PL becomes equal to or higher than the threshold value TH, as shown in (a) and (b) of fig. 9, for example. Thus, the heartbeat detecting function 64b can detect the heartbeat of the subject P from the heartbeat information acquired by the measuring apparatus 30. Fig. 9 is a diagram for explaining the relationship between the heartbeat signal PL and the threshold value TH.

(modification 4)

In the present modification, an example will be described in which the support arm 40 is applied to a mobile screen device for providing an image to the subject P placed on the top plate 10 a.

First, the configuration of the portable screen device 70 according to the present modification will be described with reference to fig. 10, 11, 12, and 13. Here, fig. 10 is a perspective view showing an example of the mobile screen device 70. Fig. 11 is a front view of the mobile screen device 70 shown in fig. 10. Fig. 12 is a side view of the mobile screen device 70 shown in fig. 10. Fig. 13 is a perspective view showing a state in which the portable screen device 70 is coupled to the top plate 10 a.

The mobile screen device 70 includes a mobile carriage 71, a screen 72, a support arm 73, and a reflection plate 74. The movable carriage 71 is a structure that moves along a rail (e.g., rail 42a in fig. 2) provided on the inner wall of the cavity 20 a. In order to improve the traveling performance on the rail, for example, wheels or a low friction material is attached to a portion of the traveling carriage 71 that contacts the rail. The traveling carriage 71 is made of a nonmagnetic material that is not affected by a magnetic field.

The movable carriage 71 is provided with a coupling portion 75 for coupling to the top plate 10a of the bed 10. As shown in fig. 13, the movable carriage 71 is coupled to the top plate 10a via a coupling portion 75. The subject P is placed on the top plate 10a with the head portion facing the side to which the mobile cart 71 is connected.

The screen 72 is erected on the mobile cart 71. An image from a projector, not shown, is projected onto the screen 72. Here, the projector is disposed on the opposite side of the bed 10 with respect to the screen 72. For example, the projector projects an image from the rear side of the stand 20 toward the screen 72 through the chamber 20 a.

The screen 72 is provided to be tiltable with respect to the moving carriage 71. Specifically, the screen 72 is provided to be tiltable by a tilting mechanism (not shown) provided in the traveling carriage 71. By adjusting the inclination angle of the screen 72 with respect to the surface of the mobile cart 71, the screen 72 is perpendicular or held at a predetermined inclination angle with respect to the surface of the mobile cart 71.

The screen 72 is preferably formed of a translucent material. As such a translucent material, translucent plastic, ground glass, or the like is preferably used. When the screen 72 is formed of a translucent material, the projection light from the projector 100 is irradiated onto the back surface (the surface on the projector 100 side) of the screen 72, and an image corresponding to the projection light is projected onto the front surface (the surface on the bed 10 side).

The screen 72 may have a planar shape or a curved shape. In the case of having a curved surface shape, the concave surface is preferably disposed so as to face the bed 10 side, that is, so as to become a surface. By orienting the concave surface toward the bed 10, the periphery of the back of the head of the subject P placed on the top plate 10a can be covered with the screen 72. This enables the field of view of the subject P to be filled with the image displayed on the screen 72, and the image to be immersed in the image.

The support arm 73 is attached to the movable carriage 71 so as to be movable in the Z-axis direction. The support arm 73 is formed of a non-magnetic material and has a curved shape along the contour of the screen 72.

Here, on the inner wall (inner periphery) 73a side of the support arm 73, the 1 st moving mechanism 76 such as a groove or a rail is provided in the circumferential direction of the support arm 73. The measuring device 30 is attached to the 1 st moving mechanism 76. The 1 st moving mechanism 76 corresponds to the 2 nd moving mechanism 42 of the 1 st embodiment described above, and moves the measuring device 30 in the circumferential direction of the support arm 73.

The support arm 73 supports the reflection plate 74 and is disposed in a space on the front surface side of the screen 72. The reflecting plate 74 is supported by the support arm 73 so as to be spaced apart from the surface of the movable carriage 71 to such an extent that the reflecting plate does not collide with the head of the object P placed on the top plate 10a in a state where the movable carriage 71 and the top plate 10a are coupled.

The reflection plate 74 is provided at substantially the uppermost portion of the support arm 73. The reflection plate 74 reflects the image appearing on the surface of the screen 72. The reflection plate 74 is formed of a nonmagnetic material, and may be formed of any material as long as it can optically reflect an object. For example, a mirror formed by vapor deposition treatment of aluminum on propylene, a half mirror having a dielectric film attached thereto, or the like can be used as the reflector 74. Thus, the subject P placed on the top plate 10a can see the image projected onto the surface of the screen 72 through the reflector 74.

The reflecting plate 74 is provided to the supporting arm 73 so as to be rotatable so that the angle of the reflecting plate 74 can be manually adjusted by the subject P. Specifically, the reflection plate 74 is provided so as to be rotatable about a rotation axis R1 by a rotation mechanism 77 provided on the support arm 73. The rotation axis R1 is provided, for example, in parallel with the X axis so that the orientation of the reflection plate 74 with respect to the surface of the screen 72 can be adjusted.

In order to adjust the position of the reflection plate 74 in the Z-axis direction, a2 nd movement mechanism 78 that enables the support arm 73 to move in the Z-axis direction is provided on the movable carriage 71. The 2 nd moving mechanism 78 moves the support arm 73 in the Z-axis direction corresponding to the 2 nd moving mechanism 42 of embodiment 1 described above.

The illumination device 50 may be provided on the support arm 73, or may be provided on the inner wall of the chamber 20 a. When the illumination device 50 is provided on the support arm 73, the illumination device 50 may be configured to be movable together with the measurement device 30 by being integrated with the measurement device 30, or may be configured to be fixedly attached to the support arm 73. In the latter case, the mounting position or the number of the lighting devices 50 is not particularly limited, but it is preferable to provide them at positions that do not hinder the rotation of the reflector 74 or the movement of the measuring device 30.

As described above, the magnetic resonance imaging apparatus 1 according to the present modification can provide an image to the subject P placed on the top board 10a via the mobile screen device 70, and can measure the heartbeat of the subject P in a non-contact manner. Thus, the magnetic resonance imaging apparatus 1 can measure the cardiac activity with high accuracy without making the subject P aware of the cardiac activity measurement. Further, the subject P can comfortably pass through the bore 20a for a relatively long time and also during MR imaging.

(modification 5)

In the above-described embodiment, the description has been given taking as an example the tunnel type magnetic resonance imaging apparatus 1 having the hollow bore 20 a. However, the magnetic resonance imaging apparatus as the application target is not limited to this type.

For example, the present invention is also applicable to a so-called open magnetic resonance imaging apparatus in which a pair of static field magnets 21, a pair of gradient field coils 22, and a pair of RF coils (a transmission coil 23 and a reception coil 24) are arranged so as to face each other across an imaging space in which the subject P is arranged. In this case, an imaging space sandwiched by the pair of static field magnets 21, the pair of gradient field coils 22, and the pair of RF coils corresponds to the bore 20a in the tunnel structure. The bed 10 in the imaging space corresponds to the "front side", and the opposite side corresponds to the "rear side".

By applying the configuration of the measurement device 30 described in the above-described embodiment to an open magnetic resonance imaging device, the magnetic resonance imaging device can position the measurement device 30 at a measurement position corresponding to the position of the top plate 10a or the posture of the subject P. Thus, the magnetic resonance imaging apparatus according to the present modification can measure the heartbeat of the subject P under appropriate conditions, and therefore can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

(modification 6)

In the above-described embodiment, an example in which the medical image diagnostic apparatus is applied to the magnetic resonance imaging apparatus 1 is described. However, the medical image diagnosis apparatus to be applied is not limited to the magnetic resonance imaging apparatus. For example, the present invention can also be applied to a Computed Tomography (CT) imaging apparatus, a Positron Emission Tomography (PET) imaging apparatus, and the like.

In addition, when applied to a computed tomography apparatus, the gantry corresponds to an apparatus (gantry) that performs CT scanning on the subject P placed on the couch 10. The imaging unit corresponds to an X-ray generation device that irradiates the subject P with X-rays, a detector that detects X-rays transmitted through the subject P, and the like. In the case of being applied to a positron emission tomography apparatus, the gantry corresponds to an apparatus for performing a PET examination on the subject P placed on the couch 10. The imaging unit corresponds to a detector or the like that detects gamma rays emitted from the subject P.

[ 2 nd embodiment ]

In embodiment 1, a configuration in which 1 measurement device 30 is movably provided to change a measurement position relative to the top plate 10a is described. In embodiment 2, a configuration will be described in which the measurement position with respect to the top plate 10a is changed relatively by selectively using a plurality of measurement devices 30 arranged at different positions with respect to the top plate 10 a. The same components as those in embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

Fig. 14 and 15 are views for explaining the measurement device 30 and the illumination device 50 provided in the gantry 20 according to the present embodiment. Here, fig. 14 is a view showing a state in the bore 20a of the gantry 20 as viewed from the bed 10 side (front side). Fig. 15 is a view showing a state in the bore 20a on the-X axis direction side as viewed from the a-a cross section of fig. 14.

As shown in fig. 14 and 15, the plurality of measurement devices 30 are provided on the inner wall of the bore 20a of the gantry 20. The measurement devices 30 are fixed at different positions from each other. For example, the measuring device 30 is provided in an arc shape around the long axis of the top plate 10 a. The position in the bore 20a where the measurement device 30 is installed is not particularly limited, but is preferably installed on the rear side or the front side where the face or the neck of the subject P can be imaged. Fig. 14 and 15 show an example in which 5 measurement devices 30(30a to 30e) are provided on the rear side in an arc shape.

Further, an illumination device 50 is provided on the inner wall of the chamber 20 a. Here, the installation position and the number of the illumination devices 50 are not particularly limited, but the illumination devices are preferably installed at positions and the number that can cover the imaging ranges of the measurement devices 30. Fig. 14 and 15 show examples in which the illumination devices 50(50a to 50d) are provided between the measurement devices 30.

Next, the processing circuit 64 (measurement control function 64a and light control function 64c) of the present embodiment will be described.

The measurement control function 64a is an example of a measurement control unit. The measurement control function 64a functions as an example of a mechanism unit together with the plurality of measurement devices 30. The measurement control function 64a selectively uses 1 measurement device 30 from among the plurality of measurement devices 30. Specifically, the measurement control function 64a selects a measurement device 30 used for imaging the subject P from the plurality of measurement devices 30, and performs measurement of the subject P using the selected measurement device 30.

Here, the measurement device 30 can be selected by the same method as the method for identifying the measurement device 30 in embodiment 1 described above. For example, when the posture of the subject P placed on the top board 10a is instructed via the input interface 6, the measurement control function 64a specifies the measurement position corresponding to the posture of the subject P, and selects the measurement device 30 disposed at the measurement position or the measurement device 30 disposed in the vicinity of the measurement position. Also, the same processing is performed when the positional information of the top plate 10a is indicated. The number of the measurement devices 30 selected by the measurement control function 64a is not limited to one, and may be plural. When a plurality of measurement devices 30 are selected, the heartbeat detection function 64b detects heartbeats of the subject P placed on the top board 10a based on heartbeat information measured by each measurement device 30.

The dimming function 64c controls the operation of the lighting device 50 in the same manner as in embodiment 1. In addition, when a plurality of the lighting apparatuses 50 are provided, the light control function 64c selects the lighting apparatus 50 used for lighting the subject P from the plurality of the lighting apparatuses 50, and lights the subject P using the selected lighting apparatus.

Here, the method of selecting the illumination device 50 is not particularly limited, and various methods can be employed. For example, the light control function 64c may select the lighting device 50 close to the position of the measurement device 30 selected by the measurement control function 64 a.

For example, when the measurement device 30b is selected from the measurement devices 30a to 30e shown in fig. 14, the light control function 64c selects one or both of the illumination device 50a and the illumination device 50b adjacent to the measurement device 30 b. The lighting devices 50 other than the selected lighting device 50 may be turned off or may emit light at low brightness.

Next, the operation of the processing circuit 64 according to the present embodiment will be described with reference to fig. 16. Fig. 16 is a flowchart showing an example of MR imaging processing executed by the processing circuit 64 according to the present embodiment. In addition, in this process, a description will be given of a process example in a case where a plurality of lighting devices 50 are provided.

First, the measurement control function 64a selects the measurement device 30 arranged at the measurement position corresponding to the posture of the subject P among the plurality of measurement devices 30 (step S21).

Next, the light control function 64c selects the lighting device 50 to be used from the plurality of lighting devices 50 based on the position of the measurement device 30 selected in step S21, and the like (step S22).

Next, the dimming function 64c determines whether or not the signal level of the heartbeat signal detected by the heartbeat detection function 64b is equal to or higher than a threshold value (step S23). Here, when the signal level of the heartbeat signal is less than the threshold value (step S23; no), the dimming function 64c increases the illuminance of the lighting device 50 by a predetermined amount (step S24), and the process returns to step S23.

On the other hand, when the signal level of the heartbeat signal is equal to or higher than the threshold value (step S23; YES), the process proceeds to step S25. Next, the imaging function 64d performs MR imaging of the subject P at the timing of a predetermined cardiac phase based on the cardiac signal detected by the cardiac beat detection function 64b (step S25).

As described above, the magnetic resonance imaging apparatus 1 according to the present embodiment selectively uses 1 measurement device 30 from among the plurality of measurement devices 30 arranged at different positions from each other to measure the heartbeat of the subject P.

Thus, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P using the measurement device 30 at the measurement position corresponding to the position of the top plate 10a or the posture of the subject P, and therefore can measure the heartbeat of the subject P under appropriate conditions. Therefore, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

The magnetic resonance imaging apparatus 1 adjusts the illuminance of the illumination device 50 based on the state of the heartbeat information (heartbeat signal) output from the measurement device 30. This enables the magnetic resonance imaging apparatus 1 to ensure the illuminance necessary for heartbeat measurement, thereby improving the measurement accuracy.

The above-described embodiment can be implemented by appropriately modifying a part of the structure or the function of the magnetic resonance imaging apparatus 1. Therefore, several modifications of the above-described embodiment will be described as other embodiments. In the following, differences from the above-described embodiments will be mainly described, and detailed description of the common points with those already described will be omitted. The modifications described below may be implemented independently or in combination as appropriate.

(modification 1)

In the above-described embodiment, the configuration in which the measurement device 30 is provided in the bore 20a is described. However, the installation position of the measurement device 30 is not limited to this, and may be installed on the end surface 20b of the mount 20 as in modification 1 of embodiment 1.

Fig. 17 is a diagram for explaining the mounting position of the measurement device 30 according to the present modification. Here, fig. 17 is a view of the mount 20 viewed from the rear side.

As shown in fig. 17, a plurality of measurement devices 30 are provided on an end surface 20b of the gantry 20 near the opening of the bore 20 a. Specifically, an example is shown in which 5 measurement devices 30(30a to 30e) are arranged in an arc-like shape in the same state as in fig. 14.

The illumination device 50 is also provided on the end face 20b of the mount 20. Fig. 8 shows an example in which the illumination devices 50(50a to 50d) are provided between the measurement devices 30 in the same state as in fig. 14.

Thus, the magnetic resonance imaging apparatus 1 according to the present modification can measure the heartbeat of the subject P using the measurement device 30 disposed at the measurement position corresponding to the position of the top plate 10a or the posture of the subject P, and therefore can perform heartbeat measurement of the subject P under appropriate conditions. Therefore, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

(modification 2)

In the above-described embodiment, a configuration in which a plurality of measurement devices 30 are directly attached to the inner wall of the bore 20a has been described. However, the present invention is not limited to this configuration, and a plurality of measurement devices 30 may be attached via the support arm 40 and the like described in embodiment 1.

Fig. 18 and 19 are views for explaining the measurement device 30 and the illumination device 50 provided in the gantry 20 of the present modification. Here, fig. 18 is a view showing a state in the bore 20a of the gantry 20 as viewed from the bed 10 side (front side). Fig. 19 is a view showing a state in the bore 20a on the-X axis direction side as viewed from the a-a cross section of fig. 18.

As shown in fig. 18 and 19, a plurality of measurement devices 30 are provided in the bore 20a of the gantry 20. Specifically, the measurement device 30 is supported by a support arm 40 provided in the bore 20 a. Here, the measurement devices 30 are fixed to the inner wall (inner periphery) 40a side of the support arm 40, and are provided at predetermined intervals. Fig. 18 and 19 show an example in which 5 measurement devices 30(30a to 30e) are provided on an inner wall (inner periphery) 40a of the support arm 40 in the same manner as in fig. 14 and 15. In fig. 18 and 19, the support arm 40 is movable in the Z-axis direction by the above-described 2 nd movement mechanism 42, but may be fixed to the rear side or the like.

Fig. 18 and 19 show an example in which a plurality of lighting devices 50 are provided on the inner wall (inner periphery) 40a side of the support arm 40. Specifically, an example is shown in which the illumination devices 50(50a to 50d) are provided between the measurement devices 30 in the same manner as in fig. 14 and 15. The installation form of the illumination device 50 is not limited to this, and may be configured to be installed on the inner wall of the cavity 20 a. The illumination device 50 may be provided integrally with the measurement device 30.

In the case of the configuration shown in fig. 18 and 19, the measurement control function 64a selects the measurement device 30 and controls the measurement position in the longitudinal direction of the top plate 10 a. For example, when the positional information of the top plate 10a in the Z-axis direction is instructed via the input interface 6, the measurement control function 64a moves the measurement device 30 (the support arm 40) to the measurement position corresponding to the positional information.

Thus, the magnetic resonance imaging apparatus 1 according to the present modification can measure the heartbeat of the subject P using the measurement device 30 disposed at the measurement position corresponding to the position of the top plate 10a or the posture of the subject P, and therefore can perform heartbeat measurement of the subject P under appropriate conditions. Further, since the magnetic resonance imaging apparatus 1 can dispose the measurement device 30 at the measurement position corresponding to the position of the top plate 10a or the posture of the subject P, the heartbeat of the subject P can be measured under appropriate conditions. Therefore, the magnetic resonance imaging apparatus 1 can measure the heartbeat of the subject P in a non-contact manner and with high accuracy.

[ embodiment 3 ]

In embodiment 1 described above, the configuration in which the stand 20 includes the measurement device 30 and the support arm 40 is described. However, the measurement device 30 and the support arm 40 may be formed as separate devices from the stand 20.

Specifically, the heartbeat measuring device may be formed as follows: the support arm 40 (or the mobile screen device 70) itself is independent by the structure in which the support arm 40 (or the mobile screen device 70) to which the measurement device 30 is attached is detachably attached to the stand 20.

In this case, the mount of the heartbeat measuring device is not limited to the gantry 20, and may be the bed 10. For example, as described with reference to fig. 12, the heartbeat measuring device (for example, the mobile screen device 70) is connected to the bed 10, and the bed 10 can be configured to include the heartbeat measuring device.

In this way, the heartbeat measuring device of the present embodiment can be detachably attached to the bed 10 or the gantry 20. Thus, the operator who operates the magnetic resonance imaging apparatus 1 can perform operations such as detaching the heartbeat measurement apparatus from the bed 10 or the gantry 20 without performing heartbeat measurement of the subject P.

While the embodiments and modifications of the present invention have been described above, the embodiments and modifications are merely presented as examples and are not intended to limit the scope of the invention. The above-described embodiments and modifications can be implemented in other various forms, and various omissions, substitutions, changes, and combinations can be made without departing from the spirit of the invention. The above-described embodiments and modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Claims

1. A medical image diagnostic apparatus is provided with:

a measurement device that images a subject placed on a top plate and outputs heartbeat information relating to heartbeats; and

and a mechanism unit that changes a measurement position of the measurement device so that a relative position of the measurement device with respect to the top plate changes.

2. The medical image diagnostic apparatus according to claim 1,

further comprises a stand for accommodating an imaging unit for acquiring a medical image of the subject,

the mechanism unit is attached to the mount.

3. The medical image diagnostic apparatus according to claim 2,

further comprises a bed for supporting the top plate,

the gantry includes a magnet for generating a static magnetic field,

the mechanism unit is provided at a position opposite to a side where the bed is disposed, with respect to the magnet of the gantry.

4. The medical image diagnostic apparatus according to claim 2,

the mechanism unit is provided on an inner wall of a hollow portion provided in the rack and into which the top plate is fed.

5. The medical image diagnostic apparatus according to claim 1,

the mechanism unit includes a moving mechanism for moving the measuring device around the longitudinal axis of the top plate.

6. The medical image diagnostic apparatus according to claim 1,

the mechanism unit includes a moving mechanism for moving the measuring device in the longitudinal direction of the top plate.

7. The medical image diagnostic apparatus according to claim 5 or 6,

the measurement device further includes a measurement control unit that controls the moving mechanism to move the measurement device to a measurement position at which the subject is imaged.

8. The medical image diagnostic apparatus according to claim 1,

the imaging apparatus further includes a measurement control unit that selects at least 1 measurement device to be used for imaging the subject from among a plurality of measurement devices arranged at different positions.

9. The medical image diagnostic apparatus according to claim 8,

the measurement control unit selects the measurement device disposed at a measurement position where the subject is imaged.

10. The medical image diagnostic apparatus according to claim 7,

the measurement control unit specifies the measurement position based on position information indicating a position of the top plate.

11. The medical image diagnostic apparatus according to claim 7,

the measurement control unit specifies the measurement position based on information indicating a posture of the subject placed on the top plate.

12. The medical image diagnostic apparatus according to claim 7,

the measurement control unit specifies the measurement position facing the face of the subject.

13. The medical image diagnostic apparatus according to claim 1,

further provided with:

an illumination device for illuminating the top plate; and

and an adjusting unit for adjusting the illuminance of the illumination device according to the state of the heartbeat information.

14. The medical image diagnostic apparatus according to claim 1,

the heartbeat measuring device further includes an adjusting unit that adjusts the sensitivity of the measuring device according to the state of the heartbeat information.

15. The medical image diagnostic apparatus according to claim 13 or 14,

the adjusting section adjusts the signal level of the heartbeat extracted from the heartbeat information.

16. The medical image diagnostic apparatus according to claim 15,

the adjustment unit repeats the adjustment until the signal level becomes equal to or higher than a threshold value.

17. A heartbeat measurement device that is attachable to and detachable from a top plate on which a subject is placed or a gantry that houses an imaging unit for acquiring data relating to generation of a medical image of the subject, the heartbeat measurement device comprising:

a measurement device that images a subject placed on the top plate and outputs heartbeat information relating to heartbeats; and