JP2002143146A - Gantry device in x-ray ct system and gantry system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gantry device in an X-ray CT system and a gantry system capable of detecting the position of the moving limit of the gantry device reliably by simple constitution and capable of flattening a floor surface. SOLUTION: A proximity sensor 31 is disposed at a position at a prescribed distance from a traveling rail 4 in the inside of the gantry device 1 mounted on the rail 4. At the positions 41 and 42 of the moving limit of the rail 4, metallic material having electromagnetic character different from the other parts (aluminum to stainless, for example) is used to be as flat as possible with the floor surface instead of provision of a dog. When the output of the sensor 31 is changed while the device 1 is moved along the rail 4, the device is judged to have reached the position of its moving limit and controlled so as to avoid moving more than it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gantry device and a gantry system in an X-ray CT system.
In particular, the present invention relates to a movement control technique for a gantry device.

[0002]

2. Description of the Related Art Angiography (Angiograph) for the purpose of diagnosing lesions in blood vessels and surrounding tissues.
y); A method of injecting a contrast agent into a blood vessel and observing the flow of the contrast agent by X-ray imaging) is known as an apparatus for realizing a diagnosis by a so-called angio apparatus. With this angio apparatus, a catheter can be easily inserted into a blood vessel.

[0003] Insertion of a catheter is performed while confirming the insertion state on an angiographic image by an angiography apparatus. However, since the angiographic image is a two-dimensional image, there are many cases where it is insufficient to accurately grasp the insertion state. As a solution to such a problem, X combined with an angio apparatus, which enables the insertion state to be grasped three-dimensionally, is proposed.
Line CT systems (also called angio-CT systems) are known.

[0004] FIG. 12 is a view showing a combination of an angio apparatus and X.
It is an external appearance perspective view showing an example of a line CT system. In the figure, 100 is an angio apparatus, 200 is a gantry apparatus for performing scanning, 300 is a table apparatus,
Hereinafter, each device will be briefly described.

[0005] The angio apparatus 100 generates X-rays.
The X-ray tube 10 includes an X-ray tube 101 and an image converter 102 that receives X-rays from the X-ray tube 101 and converts the X-ray into a visible image.
1 and the image converter 102 are fixed by a connecting arm 103 so as to face each other. Here, connecting arm 1
Reference numeral 03 is attached along the guide rail 105, and is rotatable as indicated by an arrow 106. Further, the guide rail 105 is rotatably attached to the base 104 as shown by an arrow 107.

In such a configuration, when the subject is located between the X-ray tube 101 and the image converter 102, the X-ray transmitted through the subject reaches the image converter 102, and the image converter 1
A two-dimensional X-ray image is detected by an imaging device provided in the device 02. The detected X-ray image is displayed on a monitor (not shown).

[0007] The gantry apparatus 200 is provided with an X-ray tube and an X-ray detector (not shown) at opposite positions across a hollow portion (also referred to as an opening) 201.
The structure is such that the X-ray tube and the X-ray detector rotate around the cavity while maintaining the positional relationship. Therefore,
By driving the X-ray tube and performing the detection operation of the X-ray detector while performing the rotation while the subject is positioned in the hollow portion 201, X-rays from different directions (projection angles) are obtained. Irradiation and transmission X-ray detection (scan) can be performed.
A tomographic image of the subject is arithmetically reconstructed. An apparatus for reconstructing an X-ray tomographic image and an apparatus for displaying the same are performed on an operation console (terminal) (not shown).

The table apparatus 300 places the subject on the table and then places the table on the angio apparatus 100.
Between the X-ray tube 101 and the image converter 102,
In addition, the gantry device 200 has a structure for transporting the gantry device 200 into the hollow portion 201.

The above-mentioned X-ray CT system is a system suitable for obtaining an X-ray tomographic image immediately after obtaining an angiographic image by the angio apparatus 100.

In the above system, generally,
In order to avoid interference with the gantry device 200 when the angio apparatus 100 is rotated in the directions of arrows 106 and 107, a traveling rail 400 is laid as shown, and the gantry apparatus 200 is moved along the traveling rail 400. Mobile. When the gantry device 100 is used, the gantry device 200 is moved to a position where the gantry device 200 does not interfere with the direction away from the angio device 100 (OUT side). Move to the required position on the (IN side). The movement is performed by driving wheels (not shown) of the gantry device 200 located on the rails by operating an operation panel 202 provided on the gantry device 200.

By the way, it is necessary to limit the movable range of the gantry device 200 from the viewpoints of safety and / or practicality. Conventionally, the movable range has been limited as follows.

First, as shown in FIG.
At the movement limit positions on the IN side and the OUT side on the 00, a projection 401 called a dog, which is generally made of metal, is installed. On the other hand, the gantry cover 203 in the gantry device 200
Is provided with a limit switch 250 having an actuator 250a for detecting the dog 401. This switch switches ON / OFF of a switch output signal when the actuator 250a contacts the dog 401 while moving. The gantry device 200 determines that the switch output signal has changed to reach the IN-side movement limit position (IN Limit) or the OUT-side movement limit position (OUT Limit), and performs control to prevent further movement. I do.

[0013]

However, the conventional movement control described above has various problems as described below.

First, since the limit switch 250 has a mechanically operable portion, there is a possibility that the actuator 250a may be deformed, worn, or broken, thereby increasing the maintenance cost. As shown in FIG. 13, the gantry cover 203 has a cutout 203 so that only the actuator 205a contacts the dog 401 without the gantry cover 203 coming into contact with the dog 401.
A molding process such as providing a is necessary, which is a factor in increasing the manufacturing cost of the gantry cover. Also, it is difficult to cover the limit switch 250 with a cover to protect it from a failure due to ingress of water or the like.

Further, there is a possibility that foreign matter such as dust on the traveling rail 400 is erroneously detected as the dog 401.

Further, there is a demand for eliminating irregularities on the floor surface as much as possible so as not to hinder the movement of the cart or the like on which the medical device is placed. Nevertheless, it is necessary to provide the dog 401 on the traveling rail 400, and there is a problem that the traveling rail cannot be flattened.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a simple structure that can reliably detect the movement limit position of the gantry apparatus and can make the floor surface more flat. It is an object to provide a gantry device and a gantry system in a line CT system.

[0018]

In order to achieve the above object, for example, a gantry apparatus of the present invention has the following arrangement. That is, a gantry device in an X-ray CT system mounted on a traveling rail and movable along the traveling rail, wherein a detecting means for detecting a change in electromagnetic characteristics of the traveling rail, and a detection result of the detecting means And control means for controlling the stop / movement of the movement of the gantry device based on the above.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an external perspective view showing an example of a gantry device mounted on a traveling rail in the embodiment.

As shown in the figure, the gantry apparatus 1 includes an operation panel 2 for performing a moving operation thereof, a hollow section 3 for carrying a subject placed on a table, and a gantry pedestal section 11, and a traveling rail 4. Mounted on top. Although not shown here, wheels and a motor for driving the wheels are provided inside the gantry pedestal portion 11, whereby the wheels can be moved on the traveling rail 4. Either one motor may be provided to drive any one of the wheels, or a motor for each wheel may be provided.

As described above, in the examination room in which the system is installed, various types of medical tools and the like mounted on the cart are often moved. Therefore, it is desirable that the floor surface be as flat as possible.
Therefore, as shown in FIG. 2, the rail plate of the traveling rail 4 is buried so as to be at the same height as the floor surface 5, and only the rail main body projects from the floor surface. Then, the gantry device 1 can move along the rail in a state where the groove formed in the center of the wheel 111 is fitted to the rail.

FIG. 3 shows an example of the operation panel 2. The operation panel 2 includes a first movement button 21 for moving the gantry device 1 to the IN side and a gantry device 1.
A second move button 22 is provided for moving to the OUT side. Of course, buttons for other purposes can be provided, but are not shown here for the sake of simplicity. While the operator is pressing the first movement button 21, the gantry device 1 moves to the IN side at a predetermined speed. While the second movement button 22 is being pressed, it moves to the OUT side in reverse. When both buttons are released, the movement stops.

As the material of the running rail 4, for example, stainless steel is used. Here, the conventional dog is not provided. Instead, IN Limit position 41 and OUT limit shown in FIG.
The material of the running rail at the limit position 42 is not stainless steel but aluminum, for example. Aluminum travel rails in both positions
It is installed so as to be almost flat without any steps from the stainless steel running rail at other positions.

Further, as shown in FIG. 4, inside the gantry pedestal portion 11, proximity sensors are provided at two places on an IN side and an OUT side which are separated from a floor surface (ie, a rail plate) by a predetermined distance h described later. A gantry 31 is provided and fixed to a predetermined base inside the gantry device 1.

FIG. 5 is a side view (partially cutaway view) of the gantry device 1 mounted on the traveling rail 4 shown in FIG. According to this figure, the arrangement relationship between the proximity sensor 31 and the wheel 111 will be clear. The rotation of one wheel 111 is controlled by the drive of the motor 5.

As the proximity sensor 31, for example, a magnetic proximity sensor is used. This is to detect a change in the strength of the magnetic field due to an eddy current generated on the metal side when the exciting coil of the sensor is brought close to the metal, using a semiconductor magnetic sensor or the like.

FIG. 6 is a graph showing the relationship (proximity sensor detection characteristic) between the area of the detection target and the detectable distance of the proximity sensor 31. This characteristic differs depending on the metal material, and the figure shows the characteristics of stainless steel and aluminum.

In the figure, the area of the object to be detected is L. The installation distance of the proximity sensor 31 from the detection target is B
When the distance is shorter, the proximity sensor 31 can detect whether the material of the detection target is stainless steel or aluminum. Conversely, if the installation distance is longer than A, none of the stainless steel and aluminum detection targets can be detected. When the installation distance is C, the detection target made of stainless steel can be detected, but the detection target made of aluminum cannot be detected.

In the embodiment, this property is used. That is, the installation distance h of the proximity sensor 31 from the rail plate is set to C. As described above, the traveling rail 4
Is made of stainless steel, but IN Limit position 41 and OUT
Aluminum is exceptionally used for the limit position 42. Therefore, while the gantry device 1 is traveling near the center position of the traveling rail 4, the proximity sensor 31 detects stainless steel, and the strength of the magnetic field (that is, sensor output) detected during that time is substantially constant. And the gantry device 1 is IN L
When approaching the imit position 41 or OUT Limit position 42,
The sensor output changes. This change indicates that stainless steel can no longer be detected. That is, the proximity sensor 31 functions as a unit that detects a change in the electromagnetic characteristics of the traveling rail 4. The gantry device 1 determines whether the IN limit position 41 or the OUT limit position 42
, And control is made so that the vehicle cannot proceed any further.

The material used for the traveling rail 4 is not limited to a combination of stainless steel and aluminum, as long as the proximity sensor 31 can accurately detect a change in electromagnetic characteristics.
Materials such as iron and copper may be used.

Next, FIG. 7 which is a block diagram of the movement control system of the gantry apparatus 1 in the embodiment and FIG. 8 which is a processing procedure thereof will be described.

In the figure, reference numeral 51 denotes a CPU for controlling the entire apparatus, 52 denotes a ROM for storing operation processing procedures (programs) of the CPU, and 53 denotes a CPU.
Is a RAM used as a work area. 54
Is an interface for inputting data from the X-ray CT operation console 600, 2 is the above-described operation panel, and 56 is a motor driver that controls the driving of the motor 5 under the control of the CPU 51. Reference numeral 31 denotes the above-described proximity sensor.

In the above configuration, the ROM 52 stores, for example, a program according to a flowchart as shown in FIG. Hereinafter, processing by the program will be described.

First, in step S1, a gantry moving operation input from the operation panel 2 is waited. When the gantry moving operation is performed, the process proceeds to step S2, and the motor driver 5
6 is the movement direction (OUT side / IN
The motor 5 is driven in a direction corresponding to (side). Thereby, the gantry device 1 starts moving along the traveling rail 4.

In step S3, the sensor output of the proximity sensor 31 is monitored, and as described above, the gantry 1
Is located at the movement limit position (IN Limit position 41 or OUT Limit position 42). If it is determined that it has reached the movement limit position, the process proceeds to step S5, where the motor driver 56 stops the motor drive, thereby stopping the movement of the gantry device 1. Even if there is a movement instruction in the same direction from the operation panel 2, it is not accepted so that the movement is not continued further.

If it is determined in step S3 that the current position is not the movement limit position, the flow advances to step S4 to determine whether or not the movement instruction from the operation panel 2 has been canceled. If the movement instruction has been released, the process proceeds to step S5, and the movement of the gantry device 1 is stopped. If the movement instruction has been continued, the process returns to step S2 to repeat the processing.

According to the above-described embodiment, since the movement limit position of the gantry device is detected by using the proximity sensor, it is necessary to install a dog which was conventionally required at the movement limit position of the traveling rail. lost. For this reason, the protrusion on the floor can be eliminated, and the cart or the like carrying the medical device can be smoothly moved.

Also, by using a proximity sensor,
Unlike conventional limit switches, the sensor itself does not need to contact the running rail or dog. Therefore, it is possible to avoid problems such as deformation and abrasion of a contact portion of an actuator or the like, which are conventionally required, and to reduce maintenance costs.

Conventionally, a molding process such as providing a cutout in the gantry cover was necessary so that only the actuator comes into contact with the dog without the gantry cover coming into contact with the dog. A complicated molding process is not required, which makes it possible to reduce the manufacturing cost of the gantry cover. Further, it is possible to cover the proximity sensor with a cover made of non-metal such as plastic to protect the proximity sensor from failure due to ingress of water or the like.

Further, even if there is a foreign substance such as dust on the traveling rail, the possibility of malfunction of the movement control can be reduced.

The above-described movement control technique can be applied to a table device.

FIG. 9 is an external perspective view showing a table device 500 to which the present invention can be applied.

Reference numeral 510 denotes a table on which a subject is placed. The table 510 is made of a material having a high X-ray transmittance (for example, a foam material such as acrylic is made of CFRP (Carbon Fiber Reinforced Plastics)).
Reinforced by wrapping it with the like).

Reference numeral 520 denotes a table support that supports the table 510 and also functions as a guide that slides the table 510 along the arrow A in the drawing. The table support 520 requires sufficient strength and is made of metal or the like.

Reference numeral 530 denotes a base for supporting the table support 520 so as to be movable in the direction of arrow A in the figure. That is, in this case, the sliding member is the table 510.
And the table support portion 520.

An operation unit 540 for instructing the table 510 and the table support 520 to move is attached to the base 530.
Inside, a motor (not shown) for moving the table 510 and the table support 520 and a proximity sensor (not shown) are provided.

It is necessary to limit the movable range of the table support 520. Hereinafter, the movement control mechanism of the table support unit 520 in the above configuration will be described.

Conventionally, as shown in FIG. 10, the IN and OUT movement limit positions on the side surface of the table support 520 are
While a dog 521 similar to that shown in FIG. 13 is installed, as shown in FIG.
A limit switch 535 having an actuator 535a for detecting the dog 521 is provided, and the actuator 535a detects a contact with the dog 521 during the movement of the table support 520. Therefore, as can be seen from the front view of the table device 500 shown in FIG. 11A (a view seen from F in FIG. 9 and a partially cutaway view), the base 530 itself has the dog 521.
So that only the actuator of the limit switch 535 contacts the dog 521 without contacting the
1 had to be provided. That is, the manufacturing cost of the base 530 is increased. Also, it is difficult to cover the limit switch 535 with a cover or the like to avoid a failure due to entry of water or the like.

On the other hand, according to the present invention, FIG.
As shown in (b), the proximity sensor 5 is provided inside the base 530.
50 are provided. Thus, the dog 521 provided on the table support 520 becomes unnecessary. Further, it is not necessary to provide the hollow portion 531 in the base 530. Therefore, the base 530 has a simple shape, and an increase in manufacturing cost can be avoided. Further, since the proximity sensor is used, there is no contact portion, which leads to avoiding a failure.

[0051]

As described above, according to the present invention,
It is possible to provide a gantry apparatus and a gantry system in an X-ray CT system that can reliably detect the movement limit position of the gantry apparatus with a simple configuration and can make the floor surface more flat.

[Brief description of the drawings]

FIG. 1 is an external perspective view illustrating an example of a gantry device mounted on a traveling rail according to an embodiment.

FIG. 2 is a diagram illustrating a relationship between a running rail laid state and wheels of a gantry device in the embodiment.

FIG. 3 is a diagram illustrating an example of an operation panel of the gantry device according to the embodiment.

FIG. 4 is a diagram for explaining installation of a proximity sensor in the embodiment.

FIG. 5 is a diagram showing a configuration of a gantry device and a traveling rail in the embodiment.

FIG. 6 is a diagram illustrating a relationship between an area of a detection target and a detectable distance of the proximity sensor according to the embodiment.

FIG. 7 is a block configuration diagram of a movement control system of the gantry device in the embodiment.

FIG. 8 is a flowchart illustrating a movement control process of the gantry device according to the embodiment.

FIG. 9 is an external perspective view showing a table device to which the present invention can be applied.

FIG. 10 is a diagram showing a configuration of a conventional table support unit.

FIG. 11 is a diagram showing an example of a configuration of a conventional table device and a configuration of a table device according to the present invention.

FIG. 12: X-ray CT combined with a conventional angio apparatus
It is an external appearance perspective view showing an example of a system.

FIG. 13 is a view for explaining a movement control mechanism of a conventional gantry device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Mizukoshi 4-7, Asahigaoka, Hino-shi, Tokyo 127 G F Yokogawa Medical System Co., Ltd. F-term (reference) 2G005 BA03 4C093 AA22 CA16 CA32 EC60 EE30 FA60

Claims (4)

[Claims] 1. A gantry device for an X-ray CT system mounted on a traveling rail and movable along the traveling rail, comprising: detecting means for detecting a change in electromagnetic characteristics of the traveling rail; Control means for controlling the stop / movability of the movement of the gantry device based on the detection result of the gantry device. 2. The gantry device according to claim 1, wherein the detection unit is a proximity sensor that is not in contact with the traveling rail. 3. A gantry system comprising a traveling rail and a gantry device in an X-ray CT system mounted on the traveling rail and movable along the traveling rail, wherein the traveling rail is substantially A member having electromagnetic characteristics different from other positions is disposed at a position where the gantry device is stopped, wherein the gantry device is configured to detect a change in the electromagnetic characteristics of the traveling rail. And a control means for controlling stop / movability of movement of the gantry device based on a detection result of the detection means. 4. The gantry system according to claim 3, wherein the detection unit is a proximity sensor that is not in contact with the traveling rail.