JP4508335B2 - Radiography equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for capturing a radiographic image by projecting radiation such as X-rays onto a subject.
[0002]
[Prior art]
The radiographic apparatus is used in the medical field such as medical diagnosis of a subject, and in the inspection field such as non-destructive inspection of a substance, and there are several types of receivers that receive a radiographic image.
[0003]
The first method is a radiographic method in which an intensifying screen and a radiographic film are used in close contact. This is because when the radiation that has passed through the subject enters the intensifying screen, the phosphor contained in the intensifying screen absorbs the energy of the radiation to generate fluorescence, and the radiographic film is exposed to this fluorescence, and the radiation image Is recorded as a visible image.
[0004]
The second method is known as an image recording / reproducing apparatus including a radiation detector made of a stimulable phosphor. When radiation passes through the subject and enters the stimulable phosphor, the stimulable phosphor stores a part of the radiation energy. When the stimulable phosphor is irradiated with visible light, the stimulable phosphor exhibits stimulated emission corresponding to the accumulated energy. That is, the stimulable phosphor accumulates radiographic image information of the subject, the scanning means scans the stimulable phosphor with excitation light such as laser light, and the signal reading means photoelectrically reads the photostimulated luminescence light. A recording material such as CRT or a display means such as CRT records or displays it as a visible image.
[0005]
As a third method, a radiation detector that detects radiation in real time and directly outputs the radiation is known. For example, Japanese Patent Application Laid-Open No. 8-116044 describes the principle. Digital detectors have become possible due to advances in semiconductor process technology. A scintillator and a solid-state photodetector are stacked, the scintillator converts radiation into visible light, and the solid-state detector photoelectrically converts visible light. The solid-state photodetector has a configuration in which a solid-state photodetector composed of a transparent conductive film and a conductive film is sandwiched between amorphous semiconductor films on a substrate made of quartz glass. Since the radiation detector has a flat panel shape with a thickness of several millimeters, it is easy to reduce the thickness and weight.
[0006]
FIG. 7 shows an example of a specific apparatus configuration. It is the figure which looked at the Bucky imaging stand used when the subject's S limbs, a head, an abdominal part, etc. are imaged simply from the longitudinal direction (subject's overhead direction). In this imaging table, the subject S lying on the top board 1 is exposed to X-rays from the tube T located above, and the X-rays transmitted through the subject S are received by the radiation receiver 2. To obtain a radiographic image.
[0007]
[Problems to be solved by the invention]
In the medical field, there is a demand for obtaining images of a subject from various directions with a simple operation, and there is an apparatus as shown in FIG. In this apparatus, in order to photograph the side surface of the subject S on the top board 1, instead of using the receiver 2 below the top board 1, a cassette 3 containing a film or a storage phosphor sheet is taken. It is placed on the side of the examiner S, X-rays are exposed from the side by the tube T ′, and the X-rays transmitted through the subject S are received by the film of the cassette 3.
[0008]
However, if possible, photographing using the same receiver is desired no matter what direction the photographing is performed. At that time, safety and operability should not be impaired.
[0009]
[Means for Solving the Problems]
The present invention has been made to meet the above-described demand. A radiation imaging apparatus according to a first embodiment includes a top plate on which a subject is placed, an image receiver for obtaining a radiation image of the subject, and the ceiling. A moving mechanism for changing the position of the receiver with respect to a plate, a lifting mechanism for lifting and lowering the top plate and the receiver, and an operation of the lifting mechanism according to the position of the receiver with respect to the top plate. Limiting means for limiting.
[0010]
A radiation imaging apparatus according to a second aspect includes a top plate on which a subject is placed, an image receiver for obtaining a radiation image of the subject, and a movement that makes the position of the image receiver variable with respect to the top plate. A mechanism, an elevating mechanism for raising and lowering the top plate and the receiver, and an obstacle detection for detecting an obstacle existing below the receiver when the receiver is in a horizontal state on the side of the top plate And a restricting means for restricting the lowering operation of the elevating mechanism based on detection by the detector.
[0011]
A radiation imaging apparatus according to a second aspect includes a top plate on which a subject is placed, an image receiver for obtaining a radiation image of the subject, and a movement that makes the position of the image receiver variable with respect to the top plate. A mechanism, an elevating mechanism for raising and lowering the top plate and the receiver, and a receiver installed on a support base that supports the top plate, and the receiver is in a horizontal state on the side of the top plate. And an operation switch for operating the elevating mechanism installed underneath.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. In the following description, an example using a digital radiation detector is shown as an example of a radiation receiver. However, the present invention is not limited to this, and radiation using a cassette containing a radiographic film or a storage phosphor sheet is used. It can be replaced with a receiver.
[0013]
FIG. 1 is an overall schematic diagram of the radiation imaging apparatus. An X-ray tube, which is an X-ray generator, can be selectively installed at any position of T and T ′, and projects X-rays toward the subject S from above or from the side. A top plate 102 of an imaging table such as a table or bed is used to place a subject S to be photographed, and the material thereof is an acrylic plate, a carbon plate, or wood. The top plate 102 is supported in a substantially horizontal state above the support base 101 via support columns 103 at four corners. An image receiver 104 incorporating an X-ray digital detector is disposed below the top plate 102 and on the upper surface of the support base 101. For a specific example of the X-ray digital detector, refer to JP-A-8-116044. By the moving mechanism 105, the imaging engineer (operator) pulls out the receiver 104 from the bottom of the top panel 102 in the horizontal and horizontal direction (defined as “side”) and is exposed (state H in FIG. 1). In addition, it can be rotated to the vertical state (state V in FIG. 1) after being exposed from the inside of the top plate 102 to the side. The moving mechanism 105 includes a guide rail 105a that guides the image receiver 104 in the horizontal direction of the top plate 102, and a rotation that allows the image receiver 104 exposed to the side of the top plate 102 to rotate from a horizontal state to a vertical state. And a shaft 105b. Since the receiver 104 can be pulled out from the top plate 102 and installed in either the horizontal state H or the vertical state V, the subject can be photographed from different directions by the same receiver 104. Further, as shown in FIG. 2, the hand and arm of the subject can be photographed from above while the receiver is pulled out horizontally.
[0014]
In addition, a lifting mechanism that can move the top plate 102 up and down in the vertical direction and change the height from the floor is built in the photographing stand. As a result, when the subject climbs up and down the top plate, the height of the top plate is lowered to a position where the burden on the subject is low, or it is adjusted to a height at which the assistant can work easily when transferring from the stretcher. Is possible. In addition, at the time of photographing, the photographing engineer can be set to a height at which it is easy for the subject to perform operations such as positioning of the subject, so that the burden on the photographing engineer itself is reduced.
[0015]
By the way, as shown in FIG. 2, when the subject's hand or arm is photographed while the receiver is pulled out horizontally, the subject S is photographed while sitting in a chair or a wheelchair. Below the knee of the examiner S is positioned below the receiver 104. If the top plate 1 is erroneously lowered in this state, there is a possibility that the foot of the subject S interferes with the receiver and gets caught. In addition, if the equipment in the photographing room is inadvertently placed below the receiver and the lowering operation is performed without noticing it, the receiver or the equipment may interfere. The radiation imaging apparatus of this embodiment is provided with a device for preventing such inconvenience. This will be described in detail below.
[0016]
FIG. 3 is a detailed explanatory view of the photographing stand. Between the support base 101 and the image receiver 104, a position detector 106 for detecting whether or not the image receiver 104 that moves in the horizontal direction of the top plate 102 is located below the top plate 102 is provided. The position detector 106 uses, for example, a micro switch 107. When the lever 107a extending from the micro switch 107 is positioned below the top plate 102 as shown in FIG. It turns ON, and when pulled out, it turns off and turns off. On the other hand, the support base 101 has a lifting motor 108 and a driver 109 for driving it, and the lifting mechanism 111 is driven by a signal from a controller 110 including a microprocessor so that the top plate 102 and the receiver 104 are moved. Move up and down as a unit. An operation switch 113 is connected to the controller 110 so that the photographing engineer can lift and lower the top plate 102 with his / her foot. Further, the signal from the position detector 106 is also input to the controller 110, and the lifting operation is limited based on this detection. Specifically, in the controller 110, when the position detector 106 detects that the image receiver 104 is under the top plate 102, the controller 110 moves up and down according to the input of the lift switch 113. On the other hand, when the position detector 106 detects that the receiver 104 is not under the top plate 102, the operation is restricted so that the lifting operation is not performed even if the lifting switch 113 is pressed.
[0017]
In the above configuration, when a subject is mounted on the top plate 102 and photographing is performed from above, the top plate 102 is first lowered while the receiver 104 is stored below the top plate 102, and the subject is placed on the top plate 102. Place it on the plate 102. Thereafter, the image is taken up to a height where the shooting operation is easy. Since the position detector 106 detects (ON) that the image receiver 104 is below the top plate 102, the position detector 106 performs the ascending / descending operation according to the input of the ascending / descending switch 113 by the photographing engineer.
[0018]
On the other hand, when the subject is photographed without being placed on the top plate 102, the height of the receiver 104 is set in advance to a height that facilitates the photographing operation. The imaging engineer pulls out the image receiver 104 from the bottom of the top plate 102 to the side to make it horizontal with the image receiving surface of the image receiver 104 exposed. Then, the subject is positioned on the side of the image receiver 104 and the imaging region is placed on the image receiving surface of the image receiver 104. In this state, since the detection output of the position detector 106 is OFF, the raising / lowering operation cannot be performed, and interference between the receiver 104 and the subject can be avoided. It should be noted that it is possible not to restrict both the ascending and descending operations, but to restrict only the descending operation so that the ascending operation is possible. Further, regarding the configuration and mounting location of the position detector 106, different types of sensors such as a non-contact type may be used, or may be provided at other positions such as the support base 101, the image receiver 104, the moving mechanism 105, and the like.
[0019]
Next, the operation when the receiver 104 is changed from the horizontal state to the vertical state will be described. When the image receiver 104 is set in a vertical state, the amount of protrusion of the image receiver 104 from the end of the support base 101 is small, so that it does not interfere with the subject and surrounding instruments by the lifting operation. Since imaging in the vertical state is often performed with the subject placed on the top board, in this case, it is desirable not to restrict the elevation. Therefore, even when the image receiver 104 is pulled out to the side, a logic that enables a lifting operation when the image receiver 104 is in a vertical state is employed.
[0020]
FIG. 4 is a diagram for explaining the above, and is a perspective view of a rotation connecting portion of the moving mechanism 105. An attitude detector 122 composed of a micro switch and a photo interrupter is provided in the vicinity of the rotary connecting member 121 of the moving mechanism 105, and the signal is input to the controller 110. For example, the posture detector 122 is provided with a protrusion 121a on the rotary connecting member 121, and when the receiver 104 is in a horizontal state, the protrusion 121a presses the lever 123a of the micro switch 123, and the receiver 104 is in a vertical state. If the micro switch 123 is arranged so that the protrusion 121a is separated from the lever 123a, it is possible to distinguish and detect whether the receiver 104 is in a horizontal state or a vertical state. In the controller 110, when the receiver 104 is in the horizontal state at the position where it is pulled out to the side, the lifting operation is limited as described above. On the other hand, when the posture of the receiver 104 is changed from the horizontal state to the vertical state, this is detected by the posture detector 122 so that the lifting operation can be performed even if the detection result of the position detector 106 is OFF. Remove the restriction. That is, the control is performed so that the lift is performed according to the input of the lift switch 113.
[0021]
FIG. 5 is an explanatory diagram of the second embodiment of the present invention. In the above example, the position of the image receiver 104 is detected and the raising / lowering operation is controlled by the controller 110. However, in this example, an obstacle detector 131 for detecting an obstacle is provided on the bottom surface of the image receiver 104, and this obstacle detector. In accordance with a signal from 131, the controller 110 controls the lifting operation. The obstacle detector 131 includes an operation plate 132 attached so as to cover the bottom surface of the receiver 104, a fulcrum 133 supported so as to rotate smoothly when a force is applied to the operation plate 132, and positions of the operation plate 132. It comprises a microswitch 134 that detects a change. Although the support table can be raised and lowered basically even when the receiver 104 is pulled out, a part of the subject's body or instrument is placed on the operation plate 132 located on the back of the receiver 104 during the lowering. When contact is made, the operation plate 132 detects contact by the tilt microswitch 134. The signal is immediately judged by the controller 110 and the lowering operation is stopped. If the obstacle detector 131 is configured so that the operating plate 132 can be rotated more than the braking distance from the detection to the actual stop, the obstacle detector 131 can stop quickly when it comes in contact with an obstacle such as a subject or an instrument. It becomes possible. The configuration of the obstacle detector 131 is not limited to the above example. For example, a non-contact sensor may be used for the detector. Further, the obstacle detector of this embodiment may be further provided in the configuration of FIG. 3 to constitute a double safety mechanism.
[0022]
FIG. 6 is an explanatory diagram of the third embodiment of the present invention. In this example, the installation position of the operation switch operated by the photographer with his / her foot is devised. Similarly to the above example, the controller 110 receives a signal from the raising / lowering operation switch 113 for raising / lowering the top plate 102. As shown in FIG. 6, the operation switch 113 is placed below the pulled-out receiver 104. As a result, in a state where the image receiver 104 is located below the top plate 102, the photographing engineer can easily operate the operation switch 113 as usual. However, when the image receiver 104 is exposed to the side of the top plate 102, the operation switch 113 is located below the image receiver 104, so that it is difficult to operate because the photographer's foot does not reach, and an incorrect lifting operation is performed. Can be prevented. It should be noted that a double or triple safety mechanism may be configured by adding the operation switch arrangement of the present embodiment to the configuration of FIG. 3 or FIG.
[0023]
【The invention's effect】
According to one aspect of the present invention, by restricting the operation of the lifting mechanism according to the position of the receiver with respect to the top plate, the receiver interferes with the subject by the lifting operation, and the equipment / receiver is damaged. Can be prevented in advance.
[0024]
According to another aspect of the present invention, it is possible to prevent interference between the receiver and the obstacle by restricting the lowering operation of the lifting mechanism based on the detection by the obstacle detector.
[0025]
According to another aspect of the present invention, an operation switch for operating the lifting mechanism is provided at a position where it is difficult to operate when the receiver is in a horizontal state outside the top plate, so that an erroneous operation of the photographing engineer can be prevented. Can be prevented.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a first embodiment of a radiation imaging apparatus. FIG. 2 is an explanatory diagram when a subject images a hand and an arm. FIG. 3 is a configuration diagram of the first embodiment. FIG. 5 is a configuration diagram of the second embodiment. FIG. 6 is a configuration diagram of the third embodiment. FIG. 7 is a configuration diagram of the conventional example. FIG. 8 is a configuration diagram of the conventional example. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 Support stand 102 Top plate 103 Support | pillar 104 Image receiver 105 Moving mechanism 106 Position detector 108 Lifting motor 109 Motor driver 110 Controller 113 Lifting switch 122 Attitude detector 131 Obstacle detector

Claims (2)

A top plate on which the subject is placed;
A receiver for obtaining a radiation image of the subject;
A moving mechanism that makes the position of the receiver variable with respect to the top plate;
An elevating mechanism for elevating and lowering the top plate and the receiver;
An obstacle detector for detecting an obstacle present below the receiver when the receiver is in a horizontal state on the side of the top plate;
A radiation imaging apparatus comprising: restriction means for restricting a descending operation of the elevating mechanism based on detection by the detector. A top plate on which the subject is placed;
A receiver for obtaining a radiation image of the subject;
A moving mechanism that makes the position of the receiver variable with respect to the top plate;
An elevating mechanism for elevating and lowering the top plate and the receiver;
And an operation switch for operating the elevating mechanism installed below the receiver when the receiver is in a horizontal state on the side of the top panel and installed on a support base that supports the top panel. A radiographic apparatus characterized by.

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