Image diagnostic apparatus and method of monitoring patient during examination

Abstract

To provide a technology capable of ensuring safety of a subject in advance by estimating whether the subject is in a dangerous state based on a body motion obtained from a camera video.SOLUTION: An image diagnostic apparatus includes a body motion analysis unit. The body motion analysis unit includes: a body motion indicator calculation section that calculates a quantity related to a body motion of a subject by using a video from an imaging device and calculates an indicator of the body motion by using the quantity and a coefficient determined in advance based on an examination condition; and a patient state estimation section that estimates a state of the subject by using the indicator of the body motion calculated by the body motion indicator calculation section. Alert information is output to the console based on an estimation result of the patient state estimation section.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an imaging diagnostic apparatus, and more particularly to a technique for improving the safety of a patient during an examination using an imaging diagnostic apparatus. [Background technology]

[0002] In imaging diagnostic equipment such as MRI and CT scanners, the patient (hereinafter referred to as the subject) is carried into the examination space inside the gantry, which houses the imaging equipment, while lying on a bed, and the examination is carried out. The control room where the doctor or technician who performs the examination operates the equipment is located away from the examination space, so it is not possible to grasp the condition of the subject inside the equipment.

[0003] There is a possibility that the subject may fall off the bed during the examination or move suddenly for some reason. In such a case, not only will it be impossible to continue taking images necessary for image diagnosis, but the subject's safety may also be compromised. In order to monitor such subject movements, measures such as attaching a sensor to the subject to detect body movements have been taken. However, attaching such a sensor is time-consuming and has the problem of extending the examination time. In response to this, a method has been proposed in which a camera that displays the inside of the examination space is installed, the position of the subject on the bed is recognized from the camera image, and a warning is issued when the actual position of the subject deviates from the estimated position (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-129716 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 determines whether the position of the subject has actually moved from camera images, but it cannot detect abnormal conditions that could potentially cause danger before the subject moves.

[0006] An object of the present invention is to provide a technique that can estimate whether a subject is in a dangerous state based on body movements obtained from camera images, thereby ensuring the safety of the subject in advance. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention estimates the degree of danger of the subject using body movement information detected from camera images and examination conditions that affect body movement, and issues an alert to an operator outside the examination room according to the degree of danger, allowing the operator to take action before the subject actually reaches a dangerous state.

[0008] That is, the imaging diagnostic apparatus of the present invention includes a gantry that provides an examination space, an imaging unit that images a subject placed in the examination space, a body movement analysis unit that acquires an image from an imaging device that images the inside of the gantry and analyzes the subject's movement, a console that is installed at a location separate from the gantry and has a user interface function, and a display control unit that controls output to the console. The body movement analysis unit includes a body movement index calculation unit that calculates a quantity related to the subject's body movement using the image from the imaging device and calculates an index of body movement using the quantity and a coefficient predetermined based on the examination conditions, and a patient condition estimation unit that estimates the subject's condition using the index of body movement calculated by the body movement index calculation unit, and causes the console to output alert information based on the estimation result of the patient condition estimation unit.

[0009] The patient monitoring method of the present invention is a method for monitoring a patient during imaging, which involves acquiring an image of a subject placed in an examination space, observing the subject's condition, and issuing a necessary alert according to the subject's condition, calculating a quantity related to the subject's body movement, calculating an index of the body movement using the quantity and a coefficient predetermined based on the examination conditions, and estimating the subject's condition using the index of the body movement. Predetermined alert issuance control is performed according to the estimated subject's condition. The imaging conditions here are conditions related to the patient's movement, and may include, for example, the position and posture of the subject, the examination site, and whether or not a drug has been administered to the subject. Effect of the Invention

[0010] According to the present invention, the condition of the subject is estimated using information on continuous body movements obtained from the camera image and conditions highly related to the subject's movements during the examination. Then, alert information according to the estimated condition is issued. This allows the operator to easily grasp the patient's condition in advance, and prevents dangerous situations due to falls or sudden changes in condition. In addition, since it is no longer necessary to attach sensors or the like to monitor the patient's movements, the operator's efforts and the patient's discomfort can be reduced. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of an image diagnostic apparatus to which the present invention is applied. [Diagram 2] Functional block diagram of diagnostic imaging equipment [Diagram 3] FIG. 1 is a diagram showing the operation of the image diagnostic apparatus according to the first embodiment. [Figure 4] FIG. 11 is a diagram for explaining the processing flow of the body movement analysis unit of the second embodiment. [Diagram 5] FIG. 13 is a diagram showing an example of a table used by a body movement analysis unit. [Figure 6] FIG. 13 is a diagram showing another example of a table used by the body movement analysis unit. [Figure 7] A diagram showing the monitor screen during an inspection [Figure 8] FIG. 11 is a diagram showing the flow of processing by a body movement analysis unit according to the third embodiment. [Figure 9]FIG. 1 shows an example of a monitor screen provided on a gantry. [Figure 10] A diagram showing an example of a console monitor screen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an image diagnostic apparatus according to the present invention will be described with reference to the drawings. <Embodiment 1> 1 is a diagram showing an overview of an image diagnostic apparatus 1 of this embodiment, and as shown in the figure, the image diagnostic apparatus 1 is roughly composed of an imaging section 10, a computer 20 that controls the imaging section 10 and processes signals measured by the imaging section 10 to generate images, and a console 30 that is connected to the computer 20 and is operated by an operator. Although not shown in FIG. 1, the console 30 includes input devices such as a keyboard and a mouse and a display device (monitor), and functions as a user interface section (UI section 300).

[0013] Typically, the computer 20 and the console 30 are installed in an operation room separate from the examination room in which the imaging unit 10 is located, and the operator places the subject in a specified examination space of the imaging unit 10, and then controls the operation of the imaging unit 10 while operating the console 30 in the operation room, thereby performing the examination.

[0014] The imaging unit 10 has a different configuration depending on the modality. For example, in the case of an MRI apparatus, the imaging unit 10 is equipped with a static magnetic field magnet that generates a static magnetic field, a gradient magnetic field coil that generates a gradient magnetic field, an RF transmitting coil and transmitter that irradiate a high frequency magnetic field to the subject, and a receiver to which an RF receiving coil that receives a nuclear magnetic resonance signal generated from the subject is connected, and these are housed in a gantry 11 that provides the examination space.

[0015] The gantry 11 differs depending on the direction of the static magnetic field generated by the static magnetic field magnet, but in a horizontal magnetic field type MRI apparatus, it has a cylindrical gantry shape with a cylindrical examination space formed inside. The subject 50 is carried into the examination space while lying on the bed 12, and the examination is performed.

[0016] Although the imaging unit 10 in CT and PET scanners is different, the gantry is usually cylindrical, and the subject is carried into the examination space inside. However, the present invention is not limited to a cylindrical gantry, and can be applied to a case where magnets are placed above and below the examination space, for example.

[0017] A camera (imaging device) 40 is attached to the gantry 11 to monitor the subject while the subject moves between the examination space and the outside or during the examination. The camera 40 is preferably a wide-angle camera or a tilt camera that covers a wide range or movement range of the subject. The mounting position of the camera and the number of cameras are not particularly limited, but for example, one or two cameras are installed near the openings on both sides of the gantry 11.

[0018] The camera 40 has a function of transmitting the captured image to the image diagnostic device 1 (computer 20), and the computer 20 estimates the state of the patient using the image from the camera 40. An example of the configuration of the computer 20 for realizing this function is shown in Fig. 2. Here, an example of the configuration when the image diagnostic device is an MRI device is shown as an example.

[0019] In the illustrated example, computer 20 is shown divided into processing unit 20A which performs processing as a control and calculation system for a normal image diagnostic apparatus, and processing unit 20B which performs processing related to body movement analysis, but these may be constructed within a single computer or may be separate computers.

[0020] The processing unit 20A includes an imaging control unit 21 for controlling the operation of the imaging unit, an examination flow control unit 22 for controlling an examination flow consisting of multiple images, a pulse sequence unit 23, an image reconstruction unit 24, and a memory 25, and is connected to a UI unit 300 provided in a console 30. The functions of each of these units are the same as those of a conventional MRI device, and the pulse sequence unit 23 calculates a pulse sequence to be used for imaging using a predetermined pulse sequence selected from multiple pulse sequences and its imaging parameters for each imaging included in the examination flow. The imaging control unit 21 controls the imaging unit 10 so that each element constituting the imaging unit 10 operates according to the calculated pulse sequence. The examination flow control unit controls so that imaging is performed according to a preset examination flow. The image reconstruction unit 24 performs image reconstruction and other image processing using measurement data consisting of nuclear magnetic resonance signals collected by the receiver by executing imaging. The memory 25 stores information necessary for the operation of each of these units, such as a preset examination flow and pulse sequence.

[0021] The processing unit 20B is a unit that performs body movement analysis, and receives a video signal from the camera 40, performs body movement analysis, and displays necessary information such as an alert on the monitor of the UI section 300. To realize these functions, the processing unit 20B includes a body movement analysis section 26, an analysis control section 27 that controls the operation of the body movement analysis section 26, and a display control section 28 that displays the output, which is the analysis result of the body movement analysis section 26, on a display device. The body movement analysis section 26 further includes an image processing section 261 that processes the video signal from the camera, a patient condition estimation section 262 that estimates the patient condition using information processed by the image processing section 261, and a memory that stores data and a table 263 required for the calculations of the image processing section 261 and the patient condition estimation section 262. Furthermore, the patient condition estimation section 262 includes a function of a body movement index calculation section 264 that calculates a body movement index, which will be described later. The memory of the body movement analysis section 26 may also have the function of the memory 25 of the unit 20A.

[0022] Next, an overview of the processing performed by the image diagnostic apparatus having the above configuration will be described with reference to FIG.

[0023] First, the subject 50 is laid on the bed 12 and placed in the examination space inside the gantry (subject setting), and acquisition of camera images begins (S1). Acquisition of camera images may begin before the subject 50 is transported to the examination space. At this time, the analysis control unit 27 inputs examination conditions into the body movement analysis unit 26 (S2). The examination conditions include the examination site, the subject's position during imaging (supine, prone, lateral, etc.), the direction of entry into the examination space (head-first: HF, leg-first: FF), and the presence or absence of sedation by anesthesia. The analysis control unit 27 inputs these examination conditions via input from the imaging unit 10 or the console 30. Some of the examination conditions can also be obtained from the camera images.

[0024] The image processor 261 detects vital signs such as body movement and breathing of the subject 50 from the camera image sent from the camera 40 (S3). Detection of body movement and breathing is performed, for example, as follows.

[0025] First, an image from the camera 40 is read and a motion vector is calculated. The motion vector can be calculated using a known computer vision technique such as optical flow, and the motion vector is calculated for each pixel of the image.

[0026] Next, the motion vector is used to calculate the body movement. When the camera 40 is a stereo camera, the distance from the camera is obtained and the body movement is obtained as an absolute value, but when there is a single camera, the body movement is calculated as a relative value. The body movement is calculated as a value for each small area obtained by dividing the image into a plurality of areas. At this time, different calculation formulas are used to distinguish between respiratory movement, which is dominated by the up and down movement of the abdomen, and body movement other than periodic movement (also simply called body movement), which has no regularity in the direction of movement. The calculation method will be described in detail in the embodiment described later.

[0027] The patient condition estimation unit 262 estimates whether or not the patient is in a dangerous state, or the extent of the dangerous state, from the body movement and respiratory movement detected by the image processing unit 261 (S4). In estimating a dangerous state, the body movement index calculation unit 264 first calculates an index of body movement, particularly an index representing a dangerous state, by multiplying the numerical values ​​of the body movement and respiratory movement by a weight according to the examination conditions. The patient condition estimation unit 262 judges the patient's condition by comparing the index calculated by the body movement index calculation unit 264 with a preset threshold value.

[0028] As described above, the examination conditions for determining the weights are the examination site, the subject's position during imaging, the direction of entry into the examination space, and the presence or absence of sedation. For example, when the examination site is a site affected by respiratory movement such as the abdomen, a relatively large movement is expected in a normal state, so the weight is small, but movement of the head or legs is likely to lead to dangerous movement and is therefore weighted large. Also, when a large body movement is detected in a stable position such as supine or prone position, the weight is large because it is likely to lead to dangerous movement. Sedation using anesthesia is performed when there is a high risk of the subject moving their body, such as becoming violent, and so even a small amount of movement is likely to lead to a dangerous state, so the weight is large.

[0029] The weighting value is determined in advance for each of these examination conditions, and the body movement index calculation unit 264 calculates an index by applying the weighting value of the examination conditions of the examination currently being performed to the numerical value of the body movement. When there are multiple weighting values, they may be combined and applied to calculate an index.

[0030] The estimation of a dangerous state using an index may use one threshold value to determine whether the state is at rest or at risk, but may also use multiple threshold values ​​to classify the degree of body movement into multiple stages. For example, a state of rest, slight movement, a state in which imaging needs to be stopped, a dangerous state that may lead to an accident, etc. may be determined. In addition, a state that is not a dangerous state but requires re-imaging due to a large positional deviation may be included in one stage.

[0031] The weighting values ​​used by the body movement analysis unit 26 (body movement index calculation unit 264 and patient condition estimation unit 262) to estimate a dangerous state, and the degree (stage) of the dangerous state based on the index can each be determined in advance and stored in memory as table 263, and the body movement analysis unit 26 performs processing by referring to the table when calculating the index and making the above-mentioned judgment.

[0032] The display control unit 28 presents the determination result of the patient condition estimation unit 262 on the monitor of the UI unit 300 (S5). Various presentation methods can be adopted, but basically, the determination result is displayed in the form of a warning on the monitor of the UI unit 300 together with the camera image. This display screen may display the vital information obtained by the analysis of the image processing unit 261 and the vital information on which the determination is based together with the camera image, and furthermore, in addition to displaying on the monitor, an alert may be issued using a warning sound or voice.

[0033] This allows a user located away from the subject to instantly grasp through the console 30 any changes in the patient's body movements that cannot be determined from camera images alone, particularly body movements that could lead to dangerous situations, and allows appropriate action to be taken, thereby preventing the subject from falling or other accidents.

[0034] Except when the examination must be stopped due to the result of the patient condition assessment, the above-mentioned steps S3 to S5 are repeated until the examination is completed (S6). If the examination conditions are changed by restarting the examination, or if the examination conditions differ depending on the imaging in a series of examinations including multiple imaging (S7), steps S2 to S5 are repeated.

[0035] According to this embodiment, the body movements of the subject are quantified by analyzing the camera images, and an index is calculated by weighting the values ​​related to the body movements with weights according to the examination conditions, and the degree of danger is judged using this index. This makes it possible to eliminate the need for complicated work such as having the patient wear a device to obtain vital information, and to issue an appropriate warning before the patient actually falls into a dangerous state.

[0036] Furthermore, by previously storing the indices and the results of judgments using the indices in a table, processing can be simplified and a warning can be issued without any time delay.

[0037] Next, a specific embodiment of the process will be described based on the outline of the above embodiment. Note that in the following embodiment, the configuration of the device is the same as that of embodiment 1, so duplicated explanations will be omitted and the description will be made with reference to FIG. 2 showing the device configuration as appropriate.

[0038] <Embodiment 2> In this embodiment, the image processing unit 261 calculates the amplitude (AMP) and duration (Time) of body movement from the camera image, and judges them using an index R multiplied by a weight (w) depending on the examination area, the subject's position, and whether or not sedation is present.

[0039] The flow of processing performed by the body movement analysis unit 26 will be described below with reference to Fig. 4. Fig. 4 shows processing of the video signal sent from the camera 40 for each frame.

[0040] When the image processor 261 receives one frame of image signal, it calculates the change in the subject's position using the difference from the image of the previous frame (S21). Specifically, it calculates the optical flow of the two frame images and calculates the amount of movement of feature points on the subject. The feature points are points with characteristic shapes, such as the top of the head, the tip of the chin, both shoulders, and the tips of the limbs. Alternatively, it is possible to register predetermined points, such as a specific position on a worn receiving coil, as feature points. When detecting the waveform of respiratory movement, which will be described later, it is preferable to register a site where respiratory movement can be detected as a feature point.

[0041] The feature points can be registered by accepting one or more feature points on a display screen on which an image of the subject is displayed via the UI unit 300. Alternatively, instead of registering the feature points in advance, a mask for extracting a predetermined area may be created, and the area in which the body movement should be monitored (monitoring area) may be extracted using the mask.

[0042] The amount of movement is calculated using a velocity vector that represents the change in pixel position between frames obtained by optical flow as follows: If the length and width of an image are the x and y directions, respectively, and the velocity of a specific pixel in the x direction is Vx and the velocity in the y direction is Vy, then assuming that respiratory motion is dominated by movement perpendicular to the horizontal plane (bed table surface) and that the main direction of respiratory motion is the y direction, then respiratory motion Vresp can be calculated using the following formula (1). Vresp = Vy (1)

[0043] On the other hand, since the body movement Vbody moves in an irregular direction, it is calculated using, for example, the following equation (2). Vbody = Vx (2) Depending on the direction of the body movement, it can take positive or negative values, so if we calculate its magnitude as an absolute value, for example, Abody = (Vx) 2 (3) It becomes.

[0044] When the main direction of respiratory movement is different from Vx or Vy due to the mounting angle of the camera, equation (4) may be used instead of equation (1) by using the angle θ of the XY plane with respect to the horizontal plane. Vresp=Vx cosθ-Vy sinθ (4)

[0045] As for the body movement, in order to minimize the inclusion of respiratory movement, the movement in the direction perpendicular to Vresp is taken into consideration and the calculation is performed using equations (5) and (6). Vbody=Vx sinθ+Vy cosθ (5) Abody = (Vx sinθ) 2 +(Vy cosθ) 2 (6)

[0046] As described above, when the amount of movement of each of the respiratory movement and the body movement is calculated, the image processor 261 generates a respiratory waveform and a body movement waveform based on the amount of movement of the feature point or the monitoring area (S22, S31). For the respiratory movement, the amount of movement of the feature point for detecting the respiratory movement is generated as a waveform. For the body movement, the amount of movement of a feature point (e.g., the head, the legs, or both) other than the feature point for detecting the respiratory movement is generated as a waveform.

[0047] Next, in order to determine the patient's condition, the patient condition estimation unit 262 calculates the average respiration rate from the respiration waveform (S23). If the average respiration rate calculated in step S23 is lower than the respiration rate of a normal person (e.g., 3) for a certain period of time, it is determined that an abnormal situation has occurred, that is, it is determined that an alert should be issued (S24, S25). This makes it possible to monitor conditions that could lead to serious apnea accidents. Note that, although a case where the respiration rate has been reduced for a certain period of time from the respiration waveform is shown here, it is also possible to include an abnormal situation in the determination of a condition where the respiration rate is abnormally high.

[0048] The patient condition estimation unit 262 calculates a body movement score (index) R from the body movement waveform (S32). The body movement score R is obtained by multiplying the amplitude (AMP) and duration (Time) of the body movement by a predetermined weight (W), and can be calculated, for example, using formula (7) or (8). R = w (Amp × Time) (7) R = w1·Amp+w2·Time (8)

[0049] Equation (7) is a case where the product of amplitude and duration is normalized, the value is regarded as one quantity that quantifies the body movement, and the weight is multiplied. Equation (8) is a case where the amplitude and duration are multiplied by different weights w1 and w2, respectively. In equation (8), the sum of the weighted amplitude and the weighted duration is the body movement score R, but the sum may be further weighted W to obtain the body movement score R. In addition, the index representing the body movement is not limited to the body movement score expressed by equation (7) or equation (8) as long as it is a function of the quantification of the body movement and the weight. In addition, in equations (7) and (8), one index is calculated using the amplitude and duration, but it is also possible to give an index to each of the amplitude and duration.

[0050] The weights w or w1, w2 used in calculating the index are stored in advance in the memory for each examination condition as a table 263. An example of the weight table is shown in Fig. 5. In this example, a predetermined weight is set for each examination site, depending on the body position and the presence or absence of sedation.

[0051] For the body movement score R, three thresholds, 0.1, 1, and 2, are set, and four body movement statuses separated by these thresholds are determined. Specifically, the patient state estimation unit 262 determines that an accident has occurred when R is 2 or more, that a watch-required state when R is greater than 1 and less than 2, that a slight body movement has occurred when R is greater than 0.1 and equal to or less than 1, and that a resting state when R is equal to or less than 0.1 (S331 to S333, S341 to S342). When any of the determination results is obtained, the body movement analysis unit 26 updates the determination result (body movement status) in the previous frame (S35). If the updated body movement status is "accident has occurred," an alert is issued (S36, S37), and processing of the next frame is started.

[0052] The relationship between the body movement score and the body movement status and the control according to the body movement status can be stored in advance in memory, and the analysis control unit 27 and the display control unit 28 operate based on the control procedures stored in the memory. Specifically, the patient condition estimation unit 262 uses the relationship between the body movement score and the body movement status to determine the body movement status, and the display control unit 28 performs control such as issuing an alert.

[0053] An example of body movement status determination and the subsequent display control is shown in Fig. 6. As shown in the figure, when the body movement score R is 0.1 or less and the patient is determined to be in a resting state, only the camera images and vital signs waveforms (respiratory movement waveform and body movement waveform) are displayed on the monitor screen of the UI unit, as shown on the left in Fig. 7. In the example shown in Fig. 7, one camera 40 is installed at each of the openings on both sides of the gantry 11, and images from the two cameras, an image from the head side and an image from the foot side, are displayed, and below these camera images, the respiratory movement waveform (left) and body movement waveform (right) are displayed.

[0054] Even in other body movement statuses, the display control unit 28 continues to display the camera image and vital waveforms, and displays icons and alerts with different contents on the screen according to the body movement status. For example, in the case of minor body movement, a body movement icon indicating that body movement is occurring is displayed, and in the case of a state requiring attention, a warning icon is displayed. In the case of an accident or a state extremely close to such an accident, an alert is displayed in a display mode (red, flashing, etc.) that calls the user's attention, as shown on the right side of FIG. 7. At that time, an alert sound is also issued at the same time. In addition, when it is determined that the body movement status is this, the information is also passed to the imaging control unit 21, although it is not shown in the flow of FIG. 4. In response to this, the imaging control unit 21 performs control such as stopping the scan. In this way, it is possible to automatically stop the scan when a serious accident occurs, or for the user to select automatic stopping of the scan.

[0055] As described above, according to the judgment algorithm of this embodiment (FIG. 4), abnormalities in respiratory motion and the state of body motion are monitored in parallel, and if an alert should be generated for either one, the user is immediately notified. This makes it possible to detect not only the danger of the subject moving due to body motion, but also disturbances in breathing, thereby further improving safety during examinations.

[0056] According to this embodiment, the subject's body movements are divided into a plurality of stages, from tolerable body movements to dangerous body movements, and control is performed according to each stage, so that the user can take appropriate measures against body movements and unnecessary alerts can be reduced. At this time, by predetermining (table-formatting) the relationship between the body movement score and the body movement status, and the relationship between the body movement status and the corresponding control, control such as issuing an alert can be performed in an extremely short time after the occurrence of body movement, enabling a rapid response.

[0057] Although the present embodiment has been described above with a focus on the determination algorithm in Fig. 4, the present embodiment is not limited to Fig. 4, and for example, it is possible to use a waveform from a respiratory motion monitor other than a camera image as the respiratory motion waveform. In that case, as a function of the body motion analysis unit 26 in this embodiment, step S22 in Fig. 4 is replaced with a step of reading information from the respiratory motion monitor (if the information includes a waveform, the waveform).

[0058] <Embodiment 3> In the first embodiment, the case where the patient condition is estimated while the patient is placed in the examination space has been mainly described, but the patient condition estimation function continues at least from when the door to the examination room is closed, through imaging, until the door is opened. While this estimation function is operating, while the operator remains in the examination room to set up the subject or while the bed is moving, control different from the alert during imaging may be performed.

[0059] For example, before and after the door is opened and closed (while the subject is being set up), the weight of the body movement judgment is lowered to make it less likely that an alert will be issued because the operator is in the examination room, and while the bed is being moved, no alert is sent to the monitor installed in the control room to prevent false detection of body movement alerts.

[0060] An example of the control flow is shown in Fig. 8. The processing of this embodiment is similar to that of the first embodiment shown in Fig. 3, but when issuing an alert, it is determined whether or not there is a limit to issuing an alert (S84), and if there is a limit, a process is performed to issue a conditional alert in accordance with the limit, or not to issue an alert (S87).

[0061] That is, before the subject 50 is carried into the examination space, acquisition of camera images is started (S81), and the patient condition is estimated using the camera images and the examination conditions (S82). The process of this step S82 is the same as steps S2 to S5 in Fig. 3, and if there is no restriction on the issuance of an alert (S84), an alert is issued according to the patient condition (S85), and the process returns to step S82. For example, in the second embodiment, different alerts are issued according to the value of the body movement score, as shown in steps (S331 to S333, S341 to S344, S35 to S37) in Fig. 4.

[0062] On the other hand, in the state where a restriction such as lowering the alert level or not issuing an alert is set in step S84, processing is performed in accordance with the restriction (S87). Such a restriction may be automatically switched in conjunction with the completion of setting the subject in the examination space and the movement of the bed due to the end of imaging, or, in the case where an operation terminal (gantry monitor) is provided on the console 30 or the gantry 11, it is also possible for the operator to operate the operation terminal and manually control the alert display, the presence or absence of a warning sound, the detection sensitivity, and the like.

[0063] An example of a gantry monitor that accepts user operations is shown in Fig. 9, and an example of a monitor screen of the console 30 is shown in Fig. 10. Fig. 9 shows an example of a user setting screen (Setting), in which a "Motion Alert" can be set, and while a technician who has set up the patient remains in the examination room, the alert for the operator is set to a low level, and both the automatic scan and the motion alert are turned off. In this case, step S84 in Fig. 8 is restricted so that no alert is issued, and no alert is issued even if the patient moves. After the patient is placed at a predetermined position in the examination space, the "Motion Alert" is turned on to enable normal, i.e., unrestricted, alerts to be issued.

[0064] FIG. 10 is an example of a motion alert setting screen of the console 30, where the motion alert can be set not only to ON / OFF, but also to sensitivity and notification volume. The sensitivity setting is reflected in the threshold value or the weight of the motion score when applying the motion score to the patient's condition. For example, when the patient can be visually monitored and the sensitivity is set low, the patient's condition that would normally be judged as "needing attention" is judged as "slight," reducing excessive burden on the operator. Conversely, for patients who are expected to have motion that could lead to an accident, setting the sensitivity high increases the effect of preventing accidents.

[0065] The user settings via the monitor of the console 30 or the gantry 11 can be changed depending on the stage of the examination process (during setting, during bed movement, during scanning). The conditions related to the alert set via the monitor screen are passed to the body movement analysis unit 26 via the analysis control unit 27 and are reflected in the weights and thresholds used for estimating the patient's condition, and the display control unit 28 performs an alert issuing process according to the conditions specified by the user.

[0066] According to this embodiment, body movements are monitored consistently from the setting of the subject to the end of the examination, and the estimation of the patient's condition and the issuance of alerts are controlled according to the examination process, thereby reducing the burden on the operator from excessive alert issuance and reliably preventing the occurrence of accidents such as falls.

[0067] Furthermore, according to this embodiment, the conditions for the body movement alert can be specified by the user, which enables flexible responses according to the situation. In particular, by arranging monitors that can be operated by the user both inside the examination room (gantry) and outside the examination room (console), the convenience of the user moving between inside and outside the examination room is improved.

[0068] Although an embodiment in which the image diagnostic apparatus of the present invention is applied to an MRI apparatus has been described above, the present invention can also be applied to modalities other than an MRI apparatus, such as a CT apparatus or a PET apparatus.

[0069] In the above-described embodiment, a case has been described in which unintentional body movements of a subject are detected to infer a dangerous state. However, it is also possible to use the body movement detection function to enable the subject to intentionally make body movements and to generate an alert, i.e., to use the imaging diagnostic device of the present invention as an operator call, and such specifications are also encompassed by the present invention. [Explanation of symbols]

[0070] 10:, 11: gantry, 12: bed, 20: computer, 30: console, 40: camera, 50: subject, 21: imaging control unit, 22: examination flow control unit, 23: pulse sequence unit, 24: image reconstruction unit, 25: memory, 26: body movement analysis unit, 27: analysis control unit, 28: display control unit, 261: image processing unit, 262: patient state estimation unit, 263: table, 264: body movement index calculation unit

Claims

1. a gantry which provides an examination space; an imaging unit which images a subject placed in the examination space; a body movement analysis unit which acquires an image from an imaging device which images the inside of the gantry and analyzes the movement of the subject; a console which is installed at a location separate from the gantry and has a user interface function; and a display control unit which controls an output to the console, The body movement analysis unit a body movement index calculation unit that calculates a quantity related to the body movement of the subject using the image from the imaging device, and calculates an index of the body movement using the quantity and a coefficient that is predetermined based on the examination conditions; a patient state estimation unit that estimates a state of the subject by using the body movement index calculated by the body movement index calculation unit; The image diagnostic apparatus according to claim 1, wherein the display control unit causes the console to output alert information based on an estimation result from the patient condition estimation unit.

2. 2. The imaging diagnostic apparatus according to claim 1, The examination conditions include any one of a position and posture of the subject when the subject is inserted into the examination space, an examination area, and whether or not a drug is administered to the subject in advance.

3. 2. The imaging diagnostic apparatus according to claim 1, The body movement index calculation unit calculates an amplitude and a duration of the body movement of the subject as quantities related to the body movement, and calculates the index using the amplitude and the duration of the body movement.

4. 4. The imaging diagnostic apparatus according to claim 3, The imaging diagnostic apparatus according to claim 1, wherein the coefficient is a weighting value for the amplitude and duration of the body movement.

5. 2. The imaging diagnostic apparatus according to claim 1, The imaging diagnostic apparatus according to claim 1, wherein the body movement analysis unit holds a table in which relationships between the indices of body movement, the state of the subject, and control contents are preset.

6. 6. The imaging diagnostic apparatus according to claim 5, The patient condition estimating unit estimates a condition of the subject by referring to the table.

7. 6. The imaging diagnostic apparatus according to claim 5, The display control unit refers to the table, and outputs alert information when the control content is to issue an alert.

8. 2. The imaging diagnostic apparatus according to claim 1, The imaging diagnostic apparatus, wherein the body movement analysis unit further includes an analysis control unit that controls execution and stop of body movement analysis and alert output.

9. 9. The imaging diagnostic apparatus according to claim 8, The image diagnostic apparatus according to claim 1, wherein the analysis control unit controls stopping of the analysis of the body movement and output of an alert based on a user's instruction via the console.

10. 2. The imaging diagnostic apparatus according to claim 1, An imaging diagnostic apparatus comprising: a user interface unit on at least one of the console and an outer surface of the gantry, the user interface unit receiving adjustments of the coefficients by a user.

11. 2. The imaging diagnostic apparatus according to claim 1, the quantity related to the body movement calculated by the body movement index calculation unit includes vital information of the subject, The image diagnostic apparatus according to claim 1, wherein the display control unit displays the vital sign information on a monitor of the console.

12. 2. The imaging diagnostic apparatus according to claim 1, an imaging diagnostic apparatus, characterized in that the imaging unit is a magnetic resonance imaging apparatus including a magnetic field generating unit that generates a static magnetic field and a gradient magnetic field in the examination space, a transmitting unit that irradiates the subject with a high-frequency magnetic field, and a receiving unit that receives a nuclear magnetic resonance signal generated from the subject.

13. A method for monitoring a patient during imaging, comprising: acquiring an image of a subject placed in an examination space of an imaging diagnostic apparatus; observing a condition of the subject; and issuing a necessary alert in accordance with the condition of the subject, Calculating a quantity related to the subject's body movement, and calculating a body movement index using the quantity and a coefficient that is predetermined based on the examination conditions; estimating a state of the subject using the indicator of body movement; A patient monitoring method, comprising: performing predetermined alert issuance control in response to the estimated condition of the subject.

14. 14. A method for monitoring a patient as claimed in claim 13, comprising the steps of: A patient monitoring method, comprising: controlling to stop operation of the imaging diagnostic apparatus according to the estimated condition of the subject.

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