JP2811192B2 - Continuous rotation CT scanner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Industrial application field) The present invention relates to an X-ray CT scanner of a continuously rotating type, rotating and rotating system (hereinafter referred to as a CT scanner), and in particular, a continuously rotating type CT scanner with an improved power supply method. About.

(Prior Art) Conventionally, a so-called cable take-up mechanism for winding a cable around a rotating part is required for supplying a large amount of electric power to an X-ray tube, which is an X-ray source, in a rotation-to-rotation type CT scanner. Therefore, it cannot be rotated continuously, and a pause time between scanners is required, and it is difficult to reduce the influence of body movement of the subject by shortening the imaging time. Therefore, in order to make the CT scanner a continuous rotation type, a method of supplying power from the fixed part to the rotating part by using a brush mechanism called a slip ring has come into practical use.

(Problems to be Solved by the Invention) By the way, the system using the slip ring has the following problems.

(1) Since the power is supplied by bringing the brush into contact with the rotating part, spark discharge is likely to occur due to the rotation of the contact part of the brush. For this reason, there is a possibility that an obstacle such as noise may be caused near the detector that handles a weak electric signal.

(2) In order to suppress the occurrence of the above-mentioned spark discharge and maintain insulation, a gas-insulated system in which gas is sealed is required, but this is mechanically complicated and requires a long time for maintenance. .

(3) Because the brush is worn by friction with the rotating part,
Periodic replacement is required.

The present invention has been made in view of the above points, and an object of the present invention is to realize a continuously rotating CT scanner that does not require an electrical contact mechanism such as a slip ring.

(Means for Solving the Problems) The present invention for solving the above-mentioned problems is a continuous rotation type in which an X-ray source and an X-ray detector rotate around the subject so as to be continuously rotatable.
In the CT scanner, the X-ray source and the X-ray detector have the same rotation center as the rotation center of the first rotation unit to which the X-ray source and the X-ray detector are attached. A second rotating means for freely rotating with respect to both, a rotation driving means provided on the fixed portion for applying rotational energy to the second rotating means, and a second rotating means attached to the first rotating means. Power generating means for generating electric energy in accordance with a relative linear velocity difference between a circumference of the first rotating means on an arbitrary radius of rotation and a circumference of the second rotating means on an arbitrary radius of rotation. It is characterized by doing.

(Operation) The power generating means attached to the first rotating means is rotated by a relative speed difference with respect to the second rotating means to generate electric energy.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic structural view of a CT scanner according to one embodiment of the present invention. In the figures, (a) is a front view and (b) is a side view. In the figure, reference numeral 1 denotes an object to be subjected to cross-sectional imaging by CT, and a rotating frame A11 rotates around the object 1. An X-ray tube 12 and an X-ray detector 13 are attached to the rotating frame A11, and the rotating frame A11 rotates around the subject 1. Reference numeral 14 denotes a motor A mounted on a fixed portion of a CT scanner for rotating the rotating frame A11, and transmits a rotating motion via a belt 15. 16
Is a generator attached to the rotating frame A11, and the roller 17 attached to the rotating shaft is a rotating frame B2.
1 and rotates by the rotation of the rotating frame B21. twenty two
Is a motor B attached to a fixed portion of the CT scanner for rotating the rotating frame B21 via the belt 23,
The rotating frame B21 is rotated independently of the rotating frame A11.

Next, the operation of the apparatus of the embodiment configured as described above will be described. At the start of operation, first, the switch of the motor B22 is turned on, and the rotating frame B21 is rotated via the belt 23. This rotation is performed at a rotation speed within a predetermined range regardless of whether the rotating frame A11 is stationary or rotating.

When the motor A14 is started and starts rotating by the scan starting operation of the CT scanner, the rotation is transmitted to the rotating frame A11 via the belt 15, and the rotating frame A11 is in a constant speed continuous rotation state. The rotation directions of the rotating frame A11 and the rotating frame B21 are set to be opposite. When the rotating frame A11 rotates, the generator 16 attached to the rotating frame A11 also rotates the rotating frame A11.
Rotate around the same rotation center as 11.

On the other hand, the rotating shaft of the generator 16 is
Since 17 is in contact with rotating frame B21, it rotates in proportion to the rotation speed of rotating frame B21.

Since the rotating directions of the rotating frame A11 and the rotating frame B21 are opposite to each other as described above, the rotating shaft of the generator 16 rotates in proportion to the sum of the rotating speeds of the rotating frame A11 and the rotating frame B21. Is output from the generator 16 as electric energy, and necessary electric power is supplied to the X-ray tube 12 attached to the rotating frame A11.

According to the present embodiment as described above, the following effects can be expected.

(1) An X-ray tube 12 for irradiating X-rays to a subject and an X-ray detector 13 for detecting X-rays transmitted through the subject 1 are composed of a rotating frame A1.
In a third-generation CT that is attached to and rotates together with an X-ray tube 12 attached to a rotating frame A11
A generator 16 for supplying power to the rotating frame A11 is attached to the rotating frame A11, and the rotating shaft thereof is rotated by the rotating frame B21 of another rotating mechanism provided independently of the rotating frame A11, and the difference in the number of rotations (substantially In general, the two rotating bodies rotate in opposite directions, so that the sum is generated.), So that power is supplied to the rotating X-ray tube 12 without providing an electrical contact portion such as a slip ring. be able to. Therefore, it is possible to prevent spark noise generated in the slip ring, and to eliminate wear due to abrasion to improve durability.

(2) Rotating frame A1 which is a mechanism for rotating X-ray tube 12
By having the rotating frame B21, which is a rotating mechanism independent of 1, the X-ray tube 12 can be rotated even in a stationary state where the X-ray tube 12 does not rotate.
Electric power can be supplied to the wire tube 12. Therefore, scout view shooting is also possible.

(3) Since the rotation centers of the two rotating bodies are matched, the rotation operation of the X-ray tube 12 is not affected and the X-ray tube 12 is not affected.
Power can be supplied to the X-ray tube 12 regardless of the position.

The present invention is not limited to the above embodiment.
FIG. 2 is an explanatory diagram in which only a power generation unit is extracted for explaining an apparatus according to another embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals. In the figure, (a)
FIG. 4 is an explanatory view showing the relative positions of the rotating frames A11 and B21 and the power generation part, and FIG. 4B is an enlarged view of one of the power generation units. Reference numeral 31 denotes a power generation coil wound around a magnetic iron core 32. The magnetic iron core 32 is attached to the rotating frame A11, and the plurality of power generation coils 31 are connected in series. 33
Is an exciting coil wound around a magnetic iron core 34, and a DC power supply 35 is connected to each of them to create a DC magnetic field.

In this embodiment, electric energy is obtained in the power generation coil 31 from the peripheral speed based on the difference between the rotation speeds of the rotating frame A11 and the rotating frame B21, and the X-ray tube that rotates together with the rotating frame A11 to which the power generating coil 31 is attached. Supply power to 12.

In the embodiment of FIG. 1, the following modifications are possible.

(1) Although an example is shown in which one generator is provided, a plurality of generators may be used within a physically mountable range.

(2) Although an example is shown in which a belt is used to connect the motor and the rotating frame, a gear or a direct drive system may be used.

(3) Roller 17 is used to connect rotating frame B21 and generator 16
Although an example of performing the above is shown, a gear, a belt, or the like may be used.

(4) The entire structure can be inclined (tilted) with respect to the ground plane.

(Effect of the Invention) As described in detail above, according to the present invention, a continuous rotating CT that does not require an electrical contact mechanism such as a slip ring
The power supply system of the scanner can be realized, and the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of one embodiment of the present invention, and FIG. 2 is an explanatory diagram extracting main parts of another embodiment of the present invention. 11: rotating frame A, 12: X-ray tube 13: X-ray detector, 14: motor A 15, 23: belt, 16: generator 17: roller, 21: rotating frame B 22 ... Motor B, 31 ... Generating coil 32,34 ... Magnetic iron core, 33 ... Exciting coil 35 ... DC power supply

Claims (1)

(57) [Claims] 1. A continuously rotating CT scanner in which an X-ray source and an X-ray detector rotate around a subject so as to be continuously rotatable,
The CT having the same rotation center as the rotation center of the first rotation means to which the X-ray source and the X-ray detector are attached.
A second rotating means for freely rotating with respect to both the fixed part of the scanner and the first rotating means, and a rotation provided on the fixed part for applying rotational energy to the second rotating means; A driving means, and a relative linear velocity difference between a circumference of the first rotating means on an arbitrary radius of rotation and a circumference of the second rotating means on an arbitrary radius of rotation. And a power generating means for generating electric energy according to the following.