JPS6373936A - Table apparatus of tomographic imaging apparatus - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a table device for a tomography apparatus equipped with a cradle held in a cantilevered state at the illumination position, and more particularly, to a table device for a tomography apparatus equipped with a cradle held in a cantilevered state at the illumination position. This invention relates to improving height position errors due to deflection.

(Prior Art) As a tomography device, for example, X-ray CT (Computer CT) is used.
-ed Tomoc+raphy) devices are well known. As shown in FIGS. 8(a) and 8(bl), the X-ray CT apparatus is mounted on a cradle 1 (
X-rays from an X-ray tube 5 are irradiated via a collimator 6 to a table device 3 that supports a table device 3 that supports a top plate on which a subject 2 is placed, and a subject 2 inserted into an opening 4. X the line
It consists of a gantry 8 that detects with a ray detector 7, a computer that processes the detected signal (projection data), and a console (not shown) on the right side of the CRTW that displays an image based on No. 13 from the computer. Ru.

Conventionally, the main part of the table device of this type of X1QCT apparatus has the configuration shown in FIG. That is, the cradle 1 has a roller 12Δ (the roller is rotatably installed in the carriage 13) rotating with the rail 11A in between, and a roller and rail 11B having the same configuration on the opposite side of the roller 12A.
) and supported by cradle support rollers 14. Rails 11△, 11B and support roller 14
The cradle 1 is configured to be able to move horizontally in its longitudinal direction (a gantry is installed toward the tip of the cradle 1). The carriage 13 is connected to a drive unit 16 via a wire latch 15 that is fixed to the carriage. The drive section 16 includes a motor 17 that rotates in a predetermined direction by a control section (not shown), a rotation/linear motion conversion section 22 consisting of pulleys 18 and 19, a take-up pulley 20° wire 21, etc., and a coupling 23. , and a transmission mechanism 25 that transmits the rotation of the motor 17 to the take-up pulley 20 via a gear box 24 or the like. In addition, rails 11A, 11
B, support roller 14, pulleys 18, 19, etc. are fixed to the main body of the table device.

In such a table device, at the time of observation, the subject 2 is placed on the cradle 1, and the height 1 is adjusted to determine the set position SL (height at the time of imaging) (see Fig. 8). (
a)), the subject 2 is sent into the opening 4 of the gantry (FIG. 8(b)). The horizontal movement of the cradle 1 is performed while the control section controls the rotation direction and rotation speed of the motor 17. As a result, the cradle 1 is installed at a predetermined position.

(Problem to be Solved by the Invention) However, in the table device of the conventional tomography apparatus, the cradle is installed at the imaging position by horizontally moving the cradle. When the lens flexes, the height H2 at the actual photographing position (shaded position: near the tip) deviates greatly from the previously set height Hl (HQ fixed position SL), and moreover, the tip is lowered.

For this reason, in an emergency, a large amount of force is required to pull the cradle out from the edge of the gun (in an emergency, the cradle must be pulled out
(It is decided that withdrawals can be made for 0 pounds). Furthermore, if the cradle is lowered forward, there is a risk of contact with the gantry. This is especially noticeable when tilting the gantry. Therefore, the area in which images can be captured in the height direction is considerably limited.

The present invention has been made in view of the above, and an object of the present invention is to provide a table device for a 117'i-layer imaging apparatus that reduces the error in the height of the cradle at the photographing position.

(Means for Solving the Problems) In the present invention, which achieves the above object, the table device of the layer is a shadow device: The cradle is in a cantilevered state at the most shaded position, and the cradle is in a downward-hanging configuration. The inclination angle of the rail and the height of the cradle support roller are determined so that

(Example) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing the main parts of a table device according to an example of the present invention. In FIG. 1, the same reference numerals as in FIG. 9 are used with the same meanings, so the explanation here will be omitted. The rail 31A is installed on the main body (not shown) of the table device with the front end bent at a predetermined inclination angle α with respect to the horizontal reference line 1-IL passing through the rear end 31A of the rail 31A. On the opposite side to rail 31 is rail 31B with the same configuration.
(not shown) is installed. Cradle support roller 32
The center of rotation of is located on the horizontal reference line HL, and the drive unit (
(not shown) to move the cradle 1 in a predetermined direction. That is, the cradle support roller 32
The cradle 1 is installed at a position closer to the tip 31A of A, and the cradle 1 is in a cantilevered configuration as shown in FIG.

Note that the cradle support row 532 does not necessarily need to be placed on the horizontal reference line H151, but may be placed near it. In short, as shown in FIG. 2, when the cradle 1 is in a cantilevered state, the cradle 1 should be installed so that it can be sold.

In the above configuration, at the time of examination, the subject is placed on the cradle 1, the height of the cradle 1 is adjusted, and the set position SL is determined. When the cradle support roller 32 is driven to move the subject 2 in the direction of the gantry (IN direction), the carriage 13 also runs on the rail in one direction of the gantry (the rear end 1 of the cradle moves along the rail 31A). ). This movement is performed in the direction of pushing the tip 1f of the cradle 1 upward (promoting sales of the cradle 1). Then, at the photographing position, the cradle 1 becomes cantilevered as shown in FIG. is higher than the set position SL). At this time, in the actual apparatus, the cradle 1 bends due to the weight of the subject, as shown in FIG. With this 1-bit h, the cradle part on the line of the shooting position matches the set position,
Alternatively, if the cradle 1 is located in the vicinity, the conventional height error due to deflection will be eliminated or reduced, and the longitudinal direction of the cradle 1 will be substantially horizontal.

By the way, the above-mentioned deflection h is determined by the movement path i11. of the cradle 1 in one direction of the gantry, as shown by equation (1). Q1-3
Proportional to the power.

h = W −j / 3・[・I(1) However, E
...Longitudinal elastic modulus of the cradle ■...Second moment of inertia of the cradle ~V...'JJ applied to the cradle
m<unit weight of subject + weight of cradle) Therefore, if the cradle 1 is given a movement that makes correction along the bending curve shown in FIG. 4, the height error in the cantilevered state can be reduced or It can be made zero.

On the other hand, as shown in FIG.
Let the position where the is in contact with the cradle 1 be (0, 0), the coordinates of the position of the tip of the cradle 1 at the imaging position be (x, y), and β, i, and t represent the lengths shown in the figure, then and y are represented by equations (2) and (3).

x=(,G-Ω, )-Hl-t-cos a>/
(J.

-11-(E-t-cosα)/N (2)1
°C y-(fJ-9t)・t-81nα/ρ.

Therefore, by determining the inclination angle α so as to be closest to y=h, errors due to deflection can be corrected.

FIG. 6 is a configuration diagram showing the main parts of a table device according to another embodiment of the present invention. In FIG. 6, the same symbols as in FIG. 1 are used with the same meanings. In this embodiment, the rail 31A is installed on the main body (not shown) of the table device at a predetermined inclination angle α with respect to the horizontal reference line 1-IL passing through the U end 31Δ of the rail. Further, the rotation center of the cradle support roller 32 is installed on an extension of the rail (the contact portion between the cradle and the roller is located at a higher position than the tip of the rail).

In the above configuration, at the photographing position, the cradle 1 is in a cantilevered state as shown in FIG. 7 (the tip 1 of the cradle is higher than the set position). And then, due to the weight of the subject, cradle 1! Infertility. As in the previous example, this deflection is caused by
The cradle portion located on the line of the one-door type position coincides with the set position or is located close to the set position, and the conventional height error due to deflection is eliminated or becomes small even if it exists.

(Effects of the Invention) As explained above, according to the dople device of the tomography device of the present invention, when the cradle is in a cantilever state at the imaging position, the rail is tilted so that the cradle is in the sales configuration. Since the height of the corner and the cradle support roller is determined, the error in the height of the cradle in the one-door position can be reduced and the cradle can be made substantially horizontal. Therefore, the cradle can be easily pulled out from the gantry in an emergency. Moreover, the arbitrary contact between the cradle and the gantry is eliminated, and the area in which decoy shadowing is possible can be expanded in the height direction.

[Brief explanation of the drawing]

11 and 2 show the main parts of a table device according to an embodiment of the present invention.
FIG. 6 is an explanatory diagram of the operation in the embodiment shown in FIG. 6, and FIG.
The figure is an explanatory diagram of the operation in the embodiment shown in Fig. 6, and Fig. 8 (a)
), (b) and FIG. 9 are configuration diagrams showing the main parts of a conventional table device. 1... Cradle, 2... Subject, 3... Table device, 4... Opening, 8... Gantry, 11A
and 31A...Rail, 12△...Roller, 13.
...Carriage, 32...Cradle support roller.

Claims (4)

[Claims] (1) In a table device for a tomography system equipped with a cradle that is held in a cantilevered state at the imaging position, a rail is installed on the table body at an angle of inclination to the horizontal direction, and a cradle is installed between the rail and the gantry. The inclination angle and the cradle are provided with a support roller and a cradle supported by the roller and whose rear end moves along the rail, and the inclination angle and the A table device for a tomography apparatus, characterized in that the height of a cradle support roller is determined. (2) The tomography apparatus according to claim 1, characterized in that the rail is installed with the tip downward, and the cradle support roller is installed on a horizontal reference line passing at or near the rear end of the rail. table equipment. (3) The table device for a tomography apparatus according to claim 1, wherein the rail is installed so that the top end is raised, and the cradle support roller is installed as an extension of the rail. (4) The table device for a tomography apparatus according to claim 1, wherein the inclination angle corresponds to a displacement due to flexure of the cradle at the imaging position.