JP2003079610A - Medical diagnosing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photographic image of a good quality by making the rotating balance or the like of a medical diagnosing system, which has a rotating section such as an X-ray CT device or an X-ray diagnosing device, easily and accurately adjustable. SOLUTION: A control unit 13 calculates the moving amounts and the moving directions of balance weight units 12, one or a plurality of which are provided for a rotating pedestal 1, based on the torque of a motor 6 which rotate-drives the rotating pedestal 1, and the rotating location of the rotating pedestal 1. Then, the control unit 13 display-controls the moving amounts and the moving directions on a monitor device 14. A person who adjusts this medical diagnosing system performs positional adjustments of respective balance weight units 12 wherein balance weights are provided, based on the moving amounts and the moving directions displayed on the monitor. Thus, the rotating balance or the like of the rotating pedestal 1 can be easily and accurately adjusted, and a photographic image of a good quality can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical diagnostic apparatus which is suitable for use in, for example, an X-ray CT apparatus or an X-ray diagnostic apparatus, and particularly to a weight imbalance of a rotary mount and a moment unbalance due to a centrifugal force around a tilt axis. The present invention relates to a medical diagnostic device capable of adjusting balance and the like.

[0002]

2. Description of the Related Art Conventionally, an X-ray CT for taking a tomographic image of a subject by rotating an X-ray tube and an X-ray detector in a gantry.
Although an X-ray CT apparatus such as this is known,
Due to the rotation of the X-ray tube and the X-ray detector, a weight unbalance and a moment unbalance due to the centrifugal force around the tilt axis occur, which causes a deviation between the center of gravity of the gantry rotating base and the center of scanning (scan center position). Occurs.

Since the degree of each unbalance varies from device to device, conventionally, the amount of unbalance is measured for each device.
Depending on the amount of unbalance, adjust the position and weight of the counterweight to be attached to the rotary mount so that the center of gravity of the rotary mount of the gantry and the center position of scan (scan center position) match. It was assembled and shipped.

[0004]

Conventionally, the balance adjustment is performed for each device as described above. However, when the X-ray CT device is installed in a hospital or after the clinical use is started, the X-ray tube of the rotary mount is used. There is a possibility that the balance adjusted at the time of shipment of the device may be lost due to replacement of parts such as. If this balance is lost, the center of gravity of the gantry rotary mount and the center of scanning (scan center position) are displaced, and the gantry vibrates. A decline occurs.
Particularly, in recent years, the gantry rotation speed has been increased in the X-ray CT apparatus, and this problem has become remarkable.

Specifically, when the weight balances of one X-ray CT apparatus and the other X-ray CT apparatus are the same, the gantry rotation speed of one X-ray CT apparatus is the other X-ray CT apparatus.
When the rotation speed is twice as high as the gantry rotation speed of the T apparatus, the weight due to the imbalance of one X-ray CT apparatus becomes four times that of the other X-ray CT apparatus.

Further, one X-ray CT apparatus and the other X-ray C
If the device rigidity is the same as the T device, one X-ray CT
When the rotation speed of the gantry of the apparatus becomes twice as high as the rotation speed of the gantry of the other X-ray CT apparatus, the vibration of the rotary gantry of one X-ray CT apparatus becomes four times as large.

As described above, the recent increase in the rotation speed of the gantry causes a deviation between the center of gravity of the gantry rotary gantry and the imaging center position (scan center position), and also increases the vibration applied to the gantry to increase the photographic image. Therefore, there is an increased risk of artifacts and deterioration of the resolution of the imaging density.

On the other hand, in the gantry of the conventional X-ray CT apparatus, it is relatively easy to measure the weight balance around the rotation axis, but it is difficult to measure the moment imbalance due to the centrifugal force around the tilt axis. There was a difficult problem to accurately adjust the gantry balance.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a medical diagnostic apparatus capable of easily and accurately adjusting the rotational balance and obtaining a high quality photographed image. .

[0010]

Means for Solving the Problems The medical diagnostic apparatus according to the present invention is, as means for solving the above-mentioned problems, a photographing means for photographing a subject image, a rotating means for rotating the photographing means, and It has one or a plurality of balance weight units provided on the rotating means and provided with a rotation axis direction movement adjusting mechanism which is movable at least in the rotation axis direction.

In such a medical diagnosis apparatus, the balance weight unit is moved in the rotation axis direction by the rotation axis direction movement adjusting mechanism according to the rotation state of the rotating means. This makes it possible to easily and accurately adjust the rotating state of the rotating means so as to perform normal rotation, and obtain a good quality captured image.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] In a medical diagnostic apparatus according to the present invention, an X-ray tube and an X-ray detector provided so as to face each other rotate in a gantry and It can be applied to an X-ray CT apparatus that captures a tomographic image.

[Structure of First Embodiment] First, referring to FIG.
FIG. 3 is a block diagram showing a configuration of a main part of the X-ray CT apparatus according to the first embodiment. As can be seen from FIG. 1, the X-ray CT apparatus according to the first embodiment is provided with a rotary base 1 provided in the gantry and an X-ray CT fixed to the rotary base 1 so as to face each other. It has a ray tube 2 and an X-ray detector 3, and a bug 4 fixedly provided to the rotary mount 1.

Further, the X-ray CT apparatus according to the first embodiment is provided with a photo sensor 5 for detecting the passage timing of the bag 4 which rotates with the rotation of the rotary gantry 1, and a rotary drive for rotating the rotary gantry 1. It has a motor 6, a belt receiver 7 fixedly provided on a rotating shaft 6 a of the motor 6, and a turn belt 8 for transmitting the rotational force of the motor 6 to the rotary mount 1 via the belt receiver 7.

Further, the X-ray CT apparatus according to the first embodiment has a driver 9 for rotationally driving the motor 6, and a motor 6
The rotation speed detection unit 10 that detects the rotation speed of the motor 6, the torque detection unit 11 that detects the torque of the motor 6, and the motor 6 are rotationally driven via the driver 9, and the X-ray tube 2 is irradiation-driven to subject the subject. Of the tomographic image is controlled, and the rotation balance in the scan plane (around the Z axis) is detected and displayed on the monitor device 14 based on the detection outputs from the photo sensor 5, the rotation speed detection unit 10, and the torque detection unit 11. In addition, the control unit 13 detects the balance of moments due to the centrifugal force around the tilt axis and displays the balance on the monitor device 14 based on a sinogram obtained by photographing a phantom described later. .

Further, the X-ray CT apparatus according to the first embodiment is provided at equal intervals along the outer circumference of the rotary mount 1, and is a scan plane detected by the control unit 13 and displayed on the monitor. For example, four balance weight units that can be manually moved in the rotational axis direction of the rotary gantry 1 and in the radial direction of the rotary gantry 1 according to the rotational balance inside (around the Z axis) and the moment balance due to the centrifugal force about the tilt axis. Have twelve.

In this example, the description will be made assuming that the four balance weight units 12 are provided on the rotary mount 1 at equal intervals, but two balance weight units 12 are provided at 180 ° intervals, for example. 3 at 120 degree intervals
One may be provided, or five may be provided at intervals of 72 degrees depending on the design and the like.

[Structure of Balance Weight Unit] FIG. 2
FIG. 3 is a perspective view of a balance weight unit 12 provided on the rotary mount 1. As you can see from this Figure 2,
Each balance weight unit 12 has a flat plate-shaped attachment port 20 for attaching the balance weight unit 12 to the rotary mount 1.

At approximately four corners of the mounting port 20, there are slidable holes 21 in the shape of an ellipse along the rotation axis direction of the rotary frame 1 (front and rear direction of the frame).
Are provided so as to penetrate from the upper surface side to the lower surface side.

When each balance weight unit 12 is attached to the rotary mount 1, a bolt 22 is inserted through a slide hole 21 of the mounting port 20, and the bolt 22 is attached to a screw hole provided in the rotary mount 1. Screw into. As a result, each balance weight unit 12 is fixed to the rotary mount 1.

By sliding the mounting port 20 along the slide hole 21 before completely screwing the bolt 22, the balance weight units 12 can be moved in the longitudinal direction of the gantry to adjust their positions. ing. As will be described later, the position adjustment in the longitudinal direction of the gantry is manually adjusted according to the rotational balance of the rotary gantry 1.

A stud 23, which is threaded on the entire outer peripheral portion thereof, is provided along the radial direction of the rotary mount 1 at a substantially central portion on the upper surface side of the mounting port 20 so as to project from the rotary mount 1. There is. This stud 23 has
This stud 23 is threaded on the entire outer circumference.
A substantially disk-shaped nut plate 24 having a screw hole for engaging with, a balance weight 25, and a nut plate 26 are provided in a laminated manner.

Then, the nut plate 24, the balance weight 25, and the nut plate 26 are stacked, and the nut plate 24, the balance weight 25, and the nut are tightened by screwing the nut 27 from above the nut plate 26. Plate 26 is stud 23
It is designed to be fixed to. As will be described later, the fixed position of the balance weight 25 with respect to the stud 23 and the weight (or the number) of the balance weight 25 are manually adjusted according to the rotational balance of the rotary mount 1.

[Operation of First Embodiment] The X-ray CT apparatus according to the first embodiment is provided with a "rotation balance adjustment mode" for adjusting the rotation balance of the rotary mount 1. Has been. The adjustment of the rotation balance of the rotary gantry 1 by the "rotation balance adjustment mode" is performed, for example, at the time of shipment of the X-ray CT apparatus from the factory, when the X-ray CT apparatus is installed in a hospital, or after the clinical use is started. This is done after replacing the parts.

In the "rotational balance adjustment mode", the control unit 13 shown in FIG. 1 detects and monitors the "rotational balance in the scan plane (around the Z-axis)" as described below. Detect and monitor "balance of moment due to centrifugal force around tilt axis".

Based on the monitored detection outputs, the adjuster moves each balance weight unit 12 in the longitudinal direction of the gantry to manually adjust the position, and then fixes the balance weight 25 of each balance weight unit 12 and the balance weight 25. By manually adjusting the weight (or the number of weights) of the weights 25, the rotation balance of the rotary gantry 1 is adjusted.

[Monitoring of Rotational Balance in Scan Plane (Around Z Axis)] Specifically, first, in the "rotational balance adjustment mode", the control unit 13 shown in FIG.
Controls the rotation of the motor 6 through the driver 9 so that the rotation speed is constant. As a result, the rotational force of the motor 6 is transmitted to the rotary gantry 1 via the rotary shaft 6a, the belt receiver 7 and the turn belt 8, and the rotary gantry 1 is rotationally driven at the number of rotations at the time of photographing, for example.

As described above, the hub 4 is attached to the rotary mount 1.
Is provided. Therefore, the hub 4 passes in front of the photo sensor 5 every time the rotary base 1 makes one rotation. The photo sensor 5 uses, for example, a high-level detection output as a position sensor signal at the timing when the hub 4 passes by the control unit 1.
Supply to 3. As a result, the control unit 13 is supplied with a position sensor output that becomes high level each time the rotary mount 1 makes one rotation (360 degrees), for example, as shown in FIG.

On the other hand, when the rotary base 1 is rotationally driven, the rotation speed detection unit 10 supplies continuous pulses corresponding to the rotation speed of the motor 6 to the control unit 13 as an encoded output indicating the rotation speed of the motor. Further, the torque detector 11 detects the torque of the motor 6 and outputs this torque detection output to the controller 1.
Supply to 3.

The control unit 13 counts the number of encode output pulses supplied from the rotation speed detection unit 10, and resets the position sensor signal supplied from the photosensor 5 every time the rotary mount 1 makes one rotation. This count value is reset as a pulse. As a result, the count value of the encoded output counted by the control unit 13 increases and decreases in a sawtooth shape as shown in FIG. Since the count value of the encoded output is reset every time the rotary gantry 1 makes one rotation, the count value indicates the rotational position of the rotary gantry 1. Therefore, the control unit 13 detects the rotational position of the rotary gantry 1 by detecting the count value while the rotary gantry 1 is reset.

Further, the control unit 13 controls the upper peak level and the down peak level () of the torque detection output from the torque detection unit 11 from the time the position sensor signal is supplied until the time when the next position sensor signal is supplied. Peak-to-peak: PP) is detected. Then, the shift amount of the center of gravity of the rotary gantry 1 is calculated based on each of the peak levels and the rotation position of the rotary gantry 1, and this is monitored by the monitor device 14.

More specifically, the control unit 13 first sets the upper peak level of the torque detection output to "T1" and the down peak level of the torque detection output to "T2", and then based on the following equation (1): Calculate the balance moment “M”.

M = T1-T2 (1) Next, the control unit 13 determines the unbalance moment "M" and the torque amount "mg" of the motor 6 at the predetermined rotation position of the rotary base 1. The shift amount “l” of the center of gravity of the rotary gantry 1 is calculated based on the following mathematical expression (2).

L = M / mg (2) For example, FIG. 3C shows an example of the torque detection output from the torque detection unit 11. In this case,
The torque amount (mg) of the motor 6 is at the upper peak level, and when the torque amount (mg) is at the upper peak level, the rotation position O of the rotary gantry 1 is the rotation position of 270 degrees. This is because the rotation position of the rotary mount 1 is
It shows that the center of gravity of the rotary gantry 1 is deviated in the direction of 270 degrees at the rotation position O.

The control unit 13 detects the shift amount of the center of gravity of the rotary mount 1 and the direction in which the center of gravity shifts based on the equations (1) and (2), and based on this detection result. Then, the moving amount and the weight amount of each balance weight unit 12 are calculated, and these numerical values are monitored by the monitor device 14.
Display control.

[Monitoring Moment Balance Due to Centrifugal Force Around Tilt Axis] Next, in this “rotation balance adjustment mode”, when the rotation balance in the scan plane (around the Z axis) is monitored, X
A phantom is placed on the bed of the X-ray CT apparatus and an image of it is taken. Then, the balance of the moment is adjusted by the centrifugal force around the tilt axis based on the sinogram obtained by this photographing.

In FIG. 4A, the rotation angle of the rotary mount 1 is 0 °.
4B shows the phantom 50 photographed in this state, and FIG. 4B shows the phantom 50 photographed in the state in which the rotation frame 1 has a rotation angle of 180 °. This FIG. 4 (a),
As can be seen from (b), the phantom 50 placed on the bed is embedded with a ball 51 having a diameter of, for example, about 0.5 mm above it (on the side opposite to the contact surface between the phantom 50 and the bed). The sphere 51 is formed of a member having a high CT value, and the phantom 50 is formed by covering the sphere 51 formed of a member having a high CT value with a member having a low CT value.

Further, such a phantom 50 has a ball 5
1 is placed on the bed so as to be photographed so that it is vertical to the bed.

In the X-ray CT apparatus according to the present embodiment, such a phantom 50 is provided, for example, in four stages of the X-ray detector 3 along the bed forming direction (body axis direction of the subject = Z axis direction).
The X-ray detector 3 for multi-scan, which is formed by arranging a to 3d in parallel, is used for imaging.

When the centroids of the respective parts of the gantry are all aligned with the slice plane, and when the centroids of the opposing parts and the moment of centrifugal force due to the weight are balanced, when the phantom 50 is photographed, the X-ray detector is detected. In the sinograms obtained from the X-ray detector 3b of the second channel and the X-ray detector 3c of the third channel in 3a to 3d, the influence of the sphere 51 is a sine curve as shown in FIG. Appears.

On the other hand, when the center of gravity of each part of the gantry is deviated, and when the centroids of the facing parts and the moment of centrifugal force due to the weight are not balanced,
As shown in FIG. 6, among the sinograms of the sphere 51 obtained from the X-ray detectors 3a to 3d, the sinograms obtained from the X-ray detector 3b of the second channel and the X-ray detector 3c of the third channel are changed. The amount of displacement of the center of gravity of each part of the gantry, and the amount of imbalance of the moment of centrifugal force due to the center of gravity and the weight of the opposing parts can be read from the sinogram.

[Adjustment of Rotational Balance in Scan Plane (Around Z Axis) and Moment Balance Due to Centrifugal Force Around Tilt Axis] Next, the adjuster indicates to the monitor device 14 in such a "rotational balance adjustment mode". Based on the displayed movement amount and weight amount and the sinogram of the sphere 51 obtained from each of the X-ray detectors 3a to 3d, each balance weight unit 12 is moved and the weight amount is increased / decreased within the scan plane ( Manually adjust the rotational balance around the Z-axis and the moment balance due to the centrifugal force around the tilt axis.

Specifically, each balance weight unit 12 is provided with a slide hole 21 in the mounting port 20 as described with reference to FIG. For this reason,
The adjuster slightly loosens the bolts 22 and applies a force in the longitudinal direction of the gantry to each balance weight unit 12 to move each balance weight unit 12 along the slide hole 21. Then, after this movement, the bolts 22 are tightened to fix the moved balance weight unit 12 to the rotary mount 1.

The adjuster also removes the nut 27 provided on the stud 23 and the nut plate 26. Then, the balance weight is increased by increasing the number of balance weights 25, or the balance weight is decreased by decreasing the number of balance weights 25 to manually adjust the weight of each balance weight unit 12.

Such a balance weight unit 12
The manual adjustment of the torque is based on the amount of movement and the amount of weight displayed on the monitor device 14 and the sinogram of the sphere 51 obtained from each of the X-ray detectors 3a to 3d, as shown in FIG. It is performed so that the torque detection output waveform from the detection unit 11 becomes a flat waveform.

When the torque detection output waveform from the torque detection unit 11 is a flat waveform, this means that the rotation balance in the scan plane (around the Z axis) is the optimum rotation balance, and the tilt axis rotation is It indicates that the balance of moments due to the centrifugal force of is the optimum balance.

Therefore, by manually adjusting the balance weight unit 12 so that the torque detection output waveform from the torque detection unit 11 becomes a flat waveform, the rotational balance in the scan plane (around the Z axis) and the tilt axis are obtained. It is possible to optimize the balance of moments due to the centrifugal force around them.

[Effects of First Embodiment] As is clear from the above description, the X-ray CT apparatus according to the first embodiment is based on the rotational position and torque of the rotary gantry 1 in the scan plane. The rotation balance inside (around the Z axis) is detected, and the balance of moments due to the centrifugal force around the tilt axis is detected based on the scanogram obtained by photographing the phantom 50 in which the sphere 51 is embedded. Then, the position of the balance weight unit 12 is moved and adjusted so that each balance is optimized, and the balance weight 25 of the balance weight unit 12 is increased or decreased.

As a result, in the scan plane (around the Z axis)
The rotational balance and the moment balance due to the centrifugal force around the tilt axis can be adjusted to optimum ones by simple operations. Therefore, the rotary gantry 1 can be rotated in an optimum state, and the captured image thus captured can have good image quality.

Further, the control unit 13 determines the shift amount of the center of gravity of the rotary gantry 1 based on the rotational position and torque of the rotary gantry 1,
Since the direction in which the center of gravity is deviated is detected, the movement amount and the weight amount of each balance weight unit 12 are calculated based on this detection result, and these numerical values are displayed and controlled on the monitor device 14. The adjuster can adjust each balance weight unit 12 based on the numerical value displayed on the monitor device 14. Therefore, the moving position and weight of each balance weight unit 12 can be easily adjusted.

In the description of the first embodiment,
The phantom 50 is photographed after the rotational balance in the scan plane (around the Z axis) is monitored. This is because the phantom 50 is photographed and the sinogram is obtained, and then the phantom 50 is photographed in the scan plane (around the Z axis). The rotation balance may be monitored.

[Second Embodiment] Next, the second embodiment of the present invention will be described.
The X-ray CT apparatus according to the embodiment will be described. In the first embodiment described above, each balance weight unit 12 is
In the second embodiment, the movement of each balance weight unit 12 in the radial direction of the gantry is automated, and each balance weight unit 1 is adjusted.
By manually moving 2 of the balance weight units 12 in the front-back direction, the movement of each balance weight unit 12 in the radial direction of the base can be omitted, and the overall movement adjustment is simplified.

The above-mentioned first embodiment and the second embodiment
This embodiment is different from the above embodiment only in this point. For this reason,
Only the difference will be described below, and the duplicate description will be omitted.

[Structure of the Second Embodiment] FIG. 7 is a block diagram showing the main part of the X-ray CT apparatus according to the second embodiment. As can be seen from FIG. 7, the X-ray CT apparatus according to the second embodiment moves each balance weight unit 12 in the gantry radial direction based on the rotational position and torque of the rotary gantry 1 detected by the control unit 13. By controlling the rotary mount 1
It has a weight unit driver 15 for adjusting the rotational balance within the scan plane (around the Z axis) and the moment balance due to the centrifugal force around the tilt axis.

[Structure of Balance Weight Unit] FIG. 8
(A) shows a balance weight unit 1 whose movement is controlled in the radial direction of the gantry by the weight unit driver 15.
2 is a transverse sectional view, and FIG. 8B is a top view of the balance weight unit 12.

As can be seen from FIGS. 8A and 8B, the balance weight unit 12 has a lead screw 30 rotatably provided at a substantially central portion of the mounting port 20. Also, this mounting port 2
0 is provided with a pair of guide shafts 31 facing each other with the lead screw 30 in the center.

The mounting port 20 has a motor 3
3 is provided. A washer 34 is provided on the rotary shaft 33a of the motor 33.
By engaging the worm wheel 32, which is fixed to the center of the lead screw 30 in the longitudinal direction, the rotational force of the motor 33 is reduced by the washer 34.
And the lead screw 3 through the worm wheel 32
0, so that the lead screw 30 is rotated.

The lead screw 30 (and each guide shaft 31) is provided with a disk-shaped bush 35. The bush 35 is adapted to move in the radial direction of the mount along the lead screw 30 according to the rotation direction of the motor 33. A disc-shaped weight 36 is placed on the bush 35, and is fixed to the bush 35 by a bolt 38.

In this balance weight unit 12,
Along with the weight 36, a fine adjustment weight 37 (fine adjustment weight) having a diameter smaller than that of the weight 36 and having a weight smaller than the weight of the weight 36 can be fixed. The fine adjustment weight 37 is fixed to the weight 36 with a bolt 38. The fine adjustment weight 37 is attached to the weight 36 when finely adjusting each balance.

[Balance adjusting operation of the second embodiment]
The second having such a balance weight unit 12
In the X-ray CT apparatus according to the embodiment, the control unit 13 detects the rotational position of the rotary pedestal 1 based on the encoded output from the rotational speed detection unit 10 as described above, and the torque detection unit 11 outputs the rotational position. The torque of the motor 6 is detected based on the torque detection output. Then, based on the rotational position and torque of the rotary base 1, the motor 33 of each balance weight unit 12 shown in FIGS. 8A and 8B is rotated in the clockwise or counterclockwise direction via the weight unit driver 15. Drive to rotate.

As described above, the washer 34 provided on the rotary shaft 33a of the motor 33 of each balance weight unit 12 is mechanically connected to the lead screw 30 via the worm wheel 32. Therefore, the lead screw 30 rotates according to the rotation direction of the motor 33. When the lead screw 30 rotates, the bush 35 moves in the rack radial direction, and the bush 3
The weight 36 (and the fine adjustment weight 37) placed on the table 5 moves in the pedestal radial direction.

As a result, in the scan plane (around the Z axis)
The balance weight units 12 can be automatically controlled to move in the radial direction of the gantry so that the rotational balance and the moment balance due to the centrifugal force around the tilt axis are optimal.

Further, the fine adjuster attaches the fine adjustment weight 37 to the weight 36 when finely adjusting each balance. Thereby, the weight of the weight 36 can be finely adjusted, and each balance can be finely adjusted.

Furthermore, the adjuster only needs to move each balance weight unit 12 in the radial direction of the cradle as described above.
When each balance cannot be adjusted, the movement of each balance weight unit 12 in the longitudinal direction of the gantry based on the scanogram obtained by photographing the phantom 50 (see FIGS. 4A and 4B) as described above. Read the amount. Then, the bolts 22 provided on the mounting port 20 are slightly loosened, and a force in the rack front-rear direction is applied to each balance weight unit 12, so that each balance weight unit 12 is moved back and forth along the slide hole 21. The balance weight unit 12 which is moved in the direction and then moved by tightening the bolt 22 after the movement.
Fixed to.

As a result, each balance weight unit 12 is manually operated so that the rotational balance within the scan plane (around the Z axis) of the rotary gantry 1 and the moment balance due to the centrifugal force around the tilt axis are optimally balanced. Can be fine-tuned.

[Effect of Second Embodiment] As is clear from the above description, the X-ray CT apparatus according to the second embodiment automatically determines the moving position of each balance weight unit 12 in the radial direction of the gantry. The position of each balance weight unit 12 is manually adjusted. For this reason, since the moving position of each balance weight unit 12 in the gantry radial direction can be automatically adjusted, the adjustment process of the adjuster can be simplified.

Further, the fine adjustment weight 37 is changed to the weight 36.
The weight of the weight 36 can be finely adjusted by mounting the weight 36 on the balance, and the fine adjustment of each balance can be performed, and the same effect as that of the above-described first embodiment can be obtained.

[Third Embodiment] Next, the third embodiment of the present invention will be described.
The X-ray CT apparatus according to the embodiment will be described. In the second embodiment described above, each balance weight unit 12
The weight 36 (and the fine adjustment weight 37) of No. 3 was designed to be moved in the radial direction of the cradle.
In this embodiment, the weight 36 (and the fine adjustment weight 37) of each balance weight unit 12 is moved in the longitudinal direction of the gantry.

The second embodiment and the third embodiment described above are used.
This embodiment is different from the above embodiment only in this point. For this reason,
Only the difference will be described below, and the duplicate description will be omitted.

[Structure of Third Embodiment] In the X-ray CT apparatus according to the second embodiment, each balance weight unit 1 is controlled by the weight unit driver 15 shown in FIG.
Although the second weight 36 is moved in the radial direction of the gantry, in the X-ray CT apparatus according to the third embodiment, the weight unit driver 15 is used to move each balance weight unit 1.
The second weight 36 is moved in the longitudinal direction of the gantry.

[Structure of Balance Weight Unit] FIG. 9
FIG. 1 shows a cross-sectional view of the balance weight unit 12 whose movement is controlled in the front-back direction of the gantry by the weight unit driver 15.

As can be seen from FIG. 9, the balance weight unit 12 has a mounting port 40 having a substantially concave cross section. A lead screw 41 is rotatably provided on the attachment port 40 so as to hang on the side wall portions 40a and 40b of the attachment port 40, and a guide shaft 42 is also provided.

The rotary shaft 43a of the motor 43 is connected to the lead screw 41 via a rotary connecting member 44, and the lead screw 41 is rotated according to the rotation of the motor 43.
Is designed to rotate.

The lead screw 41 and the guide shaft 4
The disk 2 is provided with a weight 45 having a disk shape, for example, so as to penetrate the lead screw 41 and the guide shaft 42. The weight 45 moves in the front-back direction of the gantry according to the rotation direction of the lead screw 41 (= rotation direction of the motor 43) while being guided by the guide shaft 42.

The weight 45 has a diameter smaller than that of the weight 45, and a weight 46 (fine adjustment weight) for fine adjustment having a weight smaller than the weight of the weight 45 can be fixed. This fine adjustment weight 46
Is fixed to the weight 45 with a bolt 47. The fine adjustment weight 46 is attached to the weight 45 when finely adjusting each balance.

[Balance adjusting operation of the third embodiment]
The third having such a balance weight unit 12
In the X-ray CT apparatus according to the embodiment, the control unit 13 detects the rotational position of the rotary pedestal 1 based on the encoded output from the rotational speed detection unit 10 as described above, and the torque detection unit 11 outputs the rotational position. The torque of the motor 6 is detected based on the torque detection output. Then, the motor 43 of each balance weight unit 12 shown in FIG. 9 is rotationally driven in the clockwise direction or the counterclockwise direction via the weight unit driver 15 based on the rotational position and torque of the rotary mount 1.

As described above, the rotary shaft 43a of the motor 43 of each balance weight unit 12 is connected to the rotary connecting member 44.
It is mechanically connected to the lead screw 41 via. Therefore, the lead screw 41 rotates according to the rotation direction of the motor 43. Then, as the lead screw 41 rotates, the weight 45 (and the fine adjustment weight 46) moves in the pedestal radial direction.

By this, in the scan plane (around the Z axis)
The weight 45 of each balance weight unit 12 can be automatically controlled to move in the longitudinal direction of the gantry so that the rotational balance and the moment balance due to the centrifugal force around the tilt axis are optimally balanced.

Further, the fine adjuster attaches the fine adjustment weight 46 to the weight 45 when finely adjusting each balance. Thereby, the weight of the weight 45 can be finely adjusted, and each balance can be finely adjusted.

[Effects of the Third Embodiment] As is clear from the above description, the X-ray CT apparatus according to the third embodiment automatically determines the movement position of each balance weight unit 12 in the longitudinal direction of the gantry. Position can be adjusted manually. For this reason, since the movement position of each balance weight unit 12 in the gantry front-back direction can be automatically adjusted, the adjustment process of the adjuster can be simplified.

Further, the fine adjustment weight 46 is changed to the weight 45.
The weight of the weight 45 can be finely adjusted by attaching the weight to the balance, and the fine adjustment of each balance can be performed, and the same effect as that of the above-described first embodiment can be obtained.

[Fourth Embodiment] In the first to third embodiments described above, the movement control of the balance weight unit is described based on the image data such as sinogram, but the image data is used. Instead of the movement control described above, one or a plurality of pressure detecting elements may be provided in the tilt mechanism, and the position of the balance weight unit may be changed based on the output of this pressure detecting element.

[Structure of Fourth Embodiment] FIG. 10 is a diagram for explaining the structure of the fourth embodiment of the present invention, and FIG. 10A is a front view of the medical diagnostic apparatus of the present invention. FIG. 10 (b) is a schematic view seen from the side. In FIG. 10A, the balance weight 12 is arranged on the rotary mount 1. In FIG. 10A, two balance weights 12 are arranged. This rotating mount 1
Actuator for chilled drive for rotating
Further, a pressure detecting means for detecting the pressure generated in this portion is arranged at the connection portion between the rotary gantry 1 and the chilled drive actuator 49. This pressure detecting means is arranged on each of the right and left sides of the rotary shaft of the rotary base 1, and is shown as a right side pressure detecting element 48R and a left side pressure detecting element 48L in FIG. 10 (a).

[Balance adjusting operation of the fourth embodiment]
FIG. 11A shows a position sensor output waveform, and a high level signal is output every time the rotary base 1 makes one rotation (360 degrees). Further, the count value of the encoded output counted by using the position sensor signal supplied each time the rotary gantry 1 makes one rotation as a reset pulse, rises and falls like a sawtooth wave as shown in FIG. 11B. The count value of this encode output is the rotary mount 1.
Is reset every one rotation, the count value indicates the rotational position of the rotary gantry 1. Figure 11
FIG. 11C shows an output waveform of the right pressure detection element 48R, and FIG. 11D shows an output waveform of the left pressure detection element 48L.

FIG. 12 is a view for explaining the structure of the rotation control section of the chilled drive actuator 49 shown in FIG. The balance weight unit 12 shown in FIG. 2 has a rotary drive unit 53 (chilled drive actuator 49) that is a drive mechanism in the gantry rotation direction, and the arithmetic control unit 54 detects the rotational position detected by the rotational position detection unit 50. Information and left and right pressure detection elements 48R, 4
Based on the detection information from 8L, the arithmetic control unit 54 calculates the imbalance in the front-rear direction to obtain the correction value. This calculated value is input to the balance weight front / rear drive unit 52 and the balance weight front / rear drive unit 51 to drive the balance weight units 12 (plurality) back and forth. By adjusting the rotary drive unit 53 with the arithmetic output value of the arithmetic control unit 54 so that the outputs of the pressure detection elements 48R and 48L are constant, the balance adjustment operation during the rotation of the rotary gantry 1 is realized.

[Other Application Examples of the Present Invention] Finally, the above-described embodiment is an example of the present invention. Therefore, the present invention is
The present invention is not limited to this embodiment. For example, in the description of the above-described embodiment, the four balance weight units 12 are provided at equal intervals on the rotary mount 1, but this is provided, for example, two at 180 ° intervals and 120 ° intervals. The same effect as described above can be obtained even if the number is changed according to the design such as providing three or five at 72 degree intervals.

Further, in the second embodiment described above, the weight 36 is controlled to move in the radial direction of the gantry, and in the third embodiment described above, the weight 45 is controlled to move in the front-rear direction of the gantry. The technique of the second embodiment and the technique of the third embodiment may be combined to allow movement control of the weight in the gantry radial direction and the gantry front-back direction. Thereby, each balance can be adjusted more accurately.

Further, although the present invention is applied to the X-ray CT apparatus in the above description of each embodiment, the present invention is also applied to an X-ray diagnostic apparatus having a rotating part and the like. Good.

Of course, other than the above, various modifications can be made in accordance with the design etc. within a range not departing from the technical idea of the present invention.

[0090]

In the medical diagnostic apparatus according to the present invention, the balance weight unit can be moved in the rotation axis direction by the rotation axis direction movement adjusting mechanism according to the rotation state of the rotating means. Therefore, the rotating state of the rotating means can be easily and accurately adjusted so as to perform normal rotation, and a high quality captured image can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an X-ray CT apparatus according to a first embodiment to which a medical diagnostic apparatus according to the present invention is applied.

FIG. 2 is a perspective view of a balance weight unit provided on the rotary mount of the X-ray CT apparatus according to the first embodiment.

FIG. 3 is a time chart of each part for explaining the adjusting method of the balance weight unit in the X-ray CT apparatus according to the first embodiment.

FIG. 4 is a diagram for explaining a phantom imaged to detect a moment balance due to a centrifugal force about a tilt axis in the X-ray CT apparatus according to the first embodiment.

FIG. 5 is a schematic diagram showing an example of a scanogram obtained by photographing a phantom when the rotary mount of the X-ray CT apparatus according to the first embodiment is normally rotating.

FIG. 6 is a schematic diagram showing an example of a scanogram obtained from a plurality of X-ray detectors when the rotary mount of the X-ray CT apparatus according to the first embodiment is abnormally rotating.

FIG. 7 is a block diagram of a main part of an X-ray CT apparatus according to a second embodiment to which a medical diagnostic apparatus according to the present invention is applied.

8A and 8B are a horizontal cross-sectional view and a top view of a balance weight unit provided on a rotary mount of the X-ray CT apparatus according to the second embodiment.

FIG. 9 is a cross-sectional view of a balance weight unit provided on the rotary mount of the X-ray CT apparatus according to the third embodiment to which the medical diagnostic apparatus according to the present invention is applied.

FIG. 10 is a diagram for explaining the configuration of the fourth embodiment of the present invention, FIG. 10 (a) is a schematic view of the medical diagnostic apparatus of the present invention seen from the front, and FIG. ) Is a schematic view seen from the side.

FIG. 11 is a diagram showing an output waveform of the pressure detecting element according to the fourth embodiment of the present invention.

FIG. 12 is a diagram illustrating a configuration of a rotation control unit according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... Rotating mount, 2 ... X-ray tube, 3 ... X-ray detector, 4 ... Bug, 5 ... Photo sensor, 6 ... Motor, 7 ... Belt receiver, 8
... Turn belt, 9 ... Driver, 10 ... Rotation speed detector,
11 ... Torque detecting part, 12 ... Balance weight unit, 13 ... Control part, 14 ... Monitor device, 15 ... Weight unit driver, 20 ... Mounting port, 21 ... Sliding hole, 22 ... Bolt, 23 ... Stud, 24 ... Nut Plate, 25 ... Balance weight, 26 ... Nut plate, 27 ... Nut, 30 ... Lead screw, 31
… Guide shaft, 32… Worm wheel, 33… Motor,
34 ... Washers, 35 ... Bushings, 36 ... Weights, 3
7 ... Fine adjustment weight, 38 ... Bolt, 40 ... Mounting port, 41 ... Lead screw, 42 ... Guide shaft, 43
... Motor, 44 ... Rotating connection member, 45 ... Weight, 46
… Fine adjustment weight, 47… Bolt

Claims (7)

[Claims] 1. An image pickup unit for picking up an image of a subject, a rotating unit for rotating the image pickup unit, and a rotation axis direction movement adjusting mechanism provided on the rotation unit and movable at least in a rotation axis direction. A medical diagnostic device having one or a plurality of balance weight units. 2. The medical diagnostic apparatus according to claim 1, wherein the balance weight unit has a radial movement adjustment mechanism that is movable in the radial direction of the rotating means. 3. The medical diagnostic apparatus according to claim 1, wherein the balance weight unit is attachable to a fine adjustment weight for fine adjustment of a small weight. 4. A rotational position detecting means for detecting a rotational position of the rotating means, a torque detecting means for detecting a torque of the rotating means, a rotational position detected by the rotational position detecting means, and the torque detecting means. And a display unit for displaying the moving position of the balance weight unit calculated by the calculating unit, based on the torque of the rotating unit detected by the calculating unit. The medical diagnostic apparatus according to any one of claims 1 to 3. 5. A rotational position detecting means for detecting a rotational position of the rotating means, a torque detecting means for detecting a torque of the rotating means, a rotational position detected by the rotational position detecting means, and the torque detecting means. Calculating means for calculating the moving position of the balance weight unit based on the torque of the rotating means detected by the control means, and controlling means for moving the balance weight unit so that the moving position is calculated by the calculating means. The medical diagnostic apparatus according to any one of claims 1 to 4, further comprising: 6. A phantom internally provided with a member showing different photographing values, wherein the balance weight unit is movement-controlled based on a photographed image obtained by photographing the phantom by the photographing means. The medical diagnostic apparatus according to any one of claims 1 to 5, wherein: 7. A means for detecting the rotational position of the rotating means and a rotational torque load in the tilt direction is provided, and a control means for controlling the forward and backward positions of the balance weight unit based on the rotational torque load and the rotational position is provided. Of Claim 1 thru | or Claim 6 characterized by these,
The medical diagnostic device according to claim 1.