JP3197796U - Collimator for X-ray fluoroscopic apparatus and X-ray fluoroscopic apparatus - Google Patents

Abstract

A collimator for an X-ray fluoroscopic imaging apparatus and an X-ray fluoroscopic imaging apparatus capable of keeping the illuminance constant regardless of differences in illuminance due to individual differences of aiming lamps or deterioration of the aiming lamp. An aiming lamp 4 for irradiating the same region as an X-ray irradiation region Wx with light, a CdS photodetector 7 for detecting the illuminance of the aiming lamp 4, and a detection result of the CdS photodetector 7 An illuminance control means for adjusting the illuminance of the aiming lamp 4, and a surface on which the light of the movable leaf 5 that moves the CdS photodetector 7 in the X direction (left and right relative to the paper surface) closer to the aiming lamp 4 hits Install on top. [Selection] Figure 1

Description

  The present invention relates to a collimator (aperture device) and an X-ray fluoroscopic apparatus used in an X-ray fluoroscopic apparatus.

  The X-ray fluoroscopic apparatus includes a table on which a subject who is a subject is placed, an X-ray tube that irradiates the subject with X-rays, an X-ray detection means (for example, a flat panel detector), and a collimator And. X-rays irradiated from the X-ray tube pass through the subject and enter the flat panel detector. The flat panel detector outputs an image signal corresponding to the incident X-ray.

  The collimator is intended to reduce the exposure dose to the subject by irradiating only the necessary region of the subject with X-rays to prevent unnecessary exposure and to reduce the exposure dose to the subject. It has an aiming lamp provided at a position mirror-conjugate with the X-ray focal point, and two sets of movable leaves and reflecting mirrors which are made of an X-ray absorber such as lead and arranged in parallel to each other. When X-ray imaging is performed, an X-ray irradiation region is set by moving two sets of movable leaves in the XY directions by appropriate driving means with the aiming lamp turned on. By irradiating X-rays from the X-ray tube in this state, X-rays are irradiated only to the irradiation region set by the two sets of movable leaves.

  On the other hand, in an X-ray diaphragm apparatus provided with an aiming lamp as a collimator, a lamp voltage for detecting the applied voltage of the lamp and comparing the detected applied voltage with the set voltage and feedback-controlling the applied voltage to the set voltage value It is driven by a control means, lamp life determination means for detecting the brightness of the lamp, comparing the detected brightness with the initial brightness of the lamp, and determining a lamp replacement time based on a decrease in illuminance, and a lamp life determination means. There exists an X-ray aperture device provided with the alerting | reporting means (refer patent document 1).

  The lamp voltage control means always controls the lamp applied voltage to a set voltage value. The lamp life determination means compares the initial brightness of the lamp (during installation or lamp replacement) with the actually measured brightness to determine a decrease in lamp illuminance. At this time, since the applied voltage of the lamp is controlled to a constant value of the set voltage value by the lamp voltage control means, since the brightness comparison is performed with the same applied voltage, it is possible to determine the decrease in illuminance by the lamp life determining means. As a result of the determination, when the illuminance decreases by a predetermined value (for example, 5% with respect to the initial brightness) or more, the lamp life determination means drives the notification means such as an indicator lamp.

  The operator can know that the lamp has reached the replacement time by the notification means. Therefore, when the lamp is turned on or during the aiming, the filament suddenly breaks and the aiming is impossible, and it is possible to cope in advance so that such an unforeseen situation does not occur. Become.

JP-A-8-322833

Conventional collimators detect the illuminance by driving the aiming lamp at a constant voltage and compare the initial illuminance with the deteriorated illuminance. Originally, there are individual differences in the lamp, and the illuminance may be different even at the same voltage. is there. In particular, in the case of an LED lamp, the illuminance may vary greatly depending on the manufacturing lot due to the characteristics of semiconductors.
Therefore, every time the lamp is replaced, adjustment such as resetting the initial illuminance is necessary. The adjustment work is carried out at the time of shipment from the factory for the first time. After the product is delivered to the customer, it is necessary to carry out the adjustment work at the customer's facility every time the lamp is replaced. This will increase costs.

  Moreover, in the conventional collimator, although the deterioration of illuminance is detected and notified, the illuminance is not detected and the illuminance is not readjusted. On the other hand, in X-ray fluoroscopic equipment, the lower limit of lamp illuminance is defined by JIS and IEC standards, and it is necessary to maintain the illuminance above the lower limit. There was also a risk that it would become impossible to aim, which would fall below the standard illuminance.

  Furthermore, in order to detect the illuminance inside the collimator, if the means for detecting the illuminance enters the light irradiation field, the light irradiation field is shaded, so the illuminance must be detected at a position that does not interfere with the light irradiation field. There was also a restriction.

  In order to solve the above-mentioned problems of the prior art, the present invention eliminates the need to adjust the illuminance at the factory or delivery destination even if there is an individual difference in the illuminance of the lamp. An object of the present invention is to provide a collimator for an X-ray fluoroscopic imaging apparatus and an X-ray fluoroscopic imaging apparatus that can always maintain the illuminance so as not to fall below.

In order to solve the above problems, a collimator for an X-ray fluoroscopic apparatus according to claim 1 of the present invention comprises:
Aiming lamp for irradiating the same area as the X-ray irradiation area with light, illuminance detection means for detecting the illuminance of the aiming lamp, and illuminance control means for adjusting the illuminance of the aiming lamp according to the detection result of the illuminance detection means And the illuminance detection means is disposed at a position where the light from the aiming lamp is irradiated inside the collimator and at a position where the X-ray irradiation area is not shielded.
The aiming lamp is usually a halogen lamp or an LED lamp, and is provided at a position that is mirror-conjugate with the X-ray focal point of the X-ray tube.

According to a second aspect of the present invention, there is provided a collimator for an X-ray fluoroscopic apparatus according to the present invention, wherein the collimator for the X-ray fluoroscopic apparatus has a movable leaf for narrowing an X-ray irradiation area, and an illuminance detecting means. Are arranged on the surface of the movable leaf where the light from the aiming lamp is irradiated.
The movable leaf for narrowing down the X-ray irradiation area is composed of a total of four movable leaves of two sets of movable leaves that move in the XY direction by appropriate driving means. An X-ray irradiation area is set in a quadrangle. The illuminance detection means is arranged on the surface irradiated with light from the aiming lamp, that is, on the movable leaf surface near the aiming lamp. By irradiating X-rays from the X-ray tube in this state, X-rays are irradiated only to the irradiation region set by the two sets of movable leaves.

  Furthermore, the X-ray fluoroscopic apparatus according to the third aspect of the present invention includes an X-ray tube that irradiates a subject with X-rays and an aiming lamp that irradiates the same region as the X-ray irradiation region with light. A collimator for fluoroscopic imaging apparatus, an X-ray detection means for detecting X-rays irradiated from the X-ray tube and transmitted through the subject, and an X-ray fluoroscopic image displayed based on an X-ray detection value by the X-ray detection means An X-ray fluoroscopic apparatus having an image display unit that performs X-ray fluoroscopic apparatus collimator comprising: an illuminance detecting means for detecting an illuminance of an aiming lamp; and an aiming lamp according to a detection result of the illuminance detecting means Illuminance control means for adjusting the illuminance of the illuminant, and the illuminance detection means is disposed in a position where the light from the aiming lamp is irradiated inside the X-ray fluoroscopic imaging collimator and at a position where the X-ray irradiation area is not shielded It is a thing.

According to the collimator for an X-ray fluoroscopic apparatus of the present invention, the illuminance of the aiming lamp is detected and the illuminance of the aiming lamp is adjusted according to the detection result. The illuminance can be kept constant regardless of the difference in illuminance or the decrease in illuminance due to the deterioration of the aiming lamp, and the illuminance adjustment work at the time of shipment or at the customer becomes unnecessary. Moreover, even if the aiming lamp is deteriorated, it does not fall below the standard specified illuminance.
Further, since the illuminance detection means is disposed at a position where the light from the aiming lamp is irradiated inside the collimator for the X-ray fluoroscopic imaging apparatus and at a position where the X-ray irradiation area is not shielded, usable X-rays The maximum irradiation area can be secured without narrowing the irradiation area.

  Furthermore, according to the X-ray fluoroscopic imaging apparatus of the present invention, it is possible not only to avoid an unexpected situation where the aiming is impossible when the lamp is turned on, but also to aim at a constant illuminance at all times, and thus preferably fluoroscopic imaging. X-ray fluoroscopic imaging can be executed quickly by confirming the position.

It is a block diagram which shows an example of the collimator for X-ray fluoroscopes of this invention. It is a block diagram which shows the structure of the illumination intensity control means of the collimator for X-ray fluoroscopes of this invention. It is a schematic diagram of the X-ray fluoroscopic apparatus of the present invention. It is a block diagram which shows the basic composition of the X-ray fluoroscope of this invention.

  Hereinafter, exemplary embodiments of a collimator for an X-ray fluoroscopic apparatus and an X-ray fluoroscopic apparatus will be described with reference to the drawings.

  FIG. 1 shows a basic configuration of a collimator 1 for an X-ray fluoroscopic apparatus according to the present invention. In FIG. 1, a collimator 1 for an X-ray fluoroscopic apparatus has a housing 8, and a lead-made tube 2 for shielding X-rays is provided therein. An appropriate width is provided on the upper surface (housing 8) and the center of the lower surface of the lead-made tubing 2 so that X-rays irradiated from the X-ray tube 10 disposed above the housing 8 can pass through without being absorbed. Holes (not shown) are formed.

Below the housing 8 are a set of movable leaves 5 that move in the X direction (left and right with respect to the paper surface) and a set of movable leaves 6 that move in the Y direction (perpendicular to the paper surface) by known driving means. Movable leaves 5 and 6 made of an X-ray absorber such as lead made of a total of two sets of two movable leaves are arranged. An arbitrary rectangular space surrounded by moving these movable leaves 5 and 6 in the XY direction forms an X-ray irradiation region Wx.
It is impossible to move the two sets of movable leaves 5 and 6 on the same plane, and either one set of the movable leaves is arranged on the side close to the aiming lamp 4, but the implementation of FIG. In the embodiment, a set of movable leaves 5 that move in the X direction are installed on the side close to the aiming lamp 4.

The aiming lamp 4 (for example, an LED lamp, a halogen lamp, etc.) is disposed on the side of the housing 8 at a position that is mirror-conjugate with the focal point F of the X-ray tube 10. The light radiated from the aiming lamp 4 enters the lead tube 2, is turned back by the reflection mirror 3 disposed at an inclination with respect to the X-ray irradiation axis, and is irradiated with the X-rays emitted from the X-ray tube 10. It is comprised so that it may irradiate with the same optical path.
The aiming lamp 4 needs to be close to an ideal point light source in order to irradiate light in the same optical path as that of the X-ray irradiation region and without blur. In addition, the light emitted from the aiming lamp 4 is designed to prevent unnecessary scattering and reflection and to be directed only into the lead-made tubes 2.

Both the X-rays emitted from the X-ray tube 10 and the light emitted from the aiming lamp 4 coincide with each other by setting the irradiation area Wx by the four movable leaves 5 and 6. Therefore, since the X-ray irradiation area can be projected by light by turning on the aiming lamp 4, the opening of the movable leaves 5, 6 is adjusted prior to the X-ray fluoroscopic imaging, that is, the X-ray irradiation area is adjusted. In addition, the fluoroscopic region can be positioned in the X-ray irradiation region.
In FIG. 1, a region indicated by a solid line from the aiming lamp 4 corresponds to a region where light is actually irradiated, and the region indicated by a broken line is an actual state when the movable leaves 5 and 6 are widened to the maximum. The maximum irradiation area Wx that can be used is shown. Therefore, the region Wv between the solid line and the broken line does not shield the X-ray irradiation region and is always a region irradiated with light.

The illuminance detection means, for example, a CdS (cadmium sulfide) photodetector 7 is disposed at an appropriate position in the region Wv between the solid line and the broken line in FIG. In the embodiment of FIG. 1, the movable leaf 5 that moves in the X direction on the side close to the aiming lamp 4 is installed on the surface on which the light strikes.
In the embodiment of FIG. 1, the CdS photodetector 7 cannot be installed on the movable leaf 6 that moves in the Y direction far from the aiming lamp 4. This is because the movable leaf 6 enters the shadow depending on the position of the movable leaf 5 moving in the X direction.

  The configuration of the illuminance control means 15 of the collimator for an X-ray fluoroscopic apparatus according to the present invention is shown in the block diagram of FIG. In FIG. 2, a CdS photodetector 7 as a means for detecting the illuminance of light emitted from the aiming lamp 4 is widely applied as a photoconductive element for converting the amount of light into a resistance value, and the resistance value increases as the received light intensity increases. Becomes smaller. Therefore, if a circuit (not shown) that divides the CdS photodetector 7 by a resistor is provided, the voltage input to the minus side of the comparator 12 varies depending on the illuminance. The voltage increases as the illuminance increases.

On the other hand, a reference voltage set in advance from the reference voltage generation circuit 11 is input to the plus side of the comparator 12, and an output value from the CdS photodetector 7 input to the minus side of the comparator 12 (voltage that varies depending on illuminance). Compared with The reference voltage is set to a voltage corresponding to when the illuminance is 300 lux, for example. Therefore, a value corresponding to the difference between the voltage corresponding to the actual illuminance and the reference voltage is output from the comparator 12 and output to the current control circuit 13.
The value output to the current control circuit 13 is, for example, a 4-bit counter (not shown) only during (reference voltage)> (voltage changing according to illuminance), that is, until the illuminance detected by the CdS photodetector 7 reaches 300 lux. 2), and this value is converted into an analog voltage by a DA converter (not shown) and output to the current control circuit 13.

The current control circuit 13 uses a known constant current IC (for example, LTM8042 manufactured by Linear Technology Co., Ltd.) using a value (analog voltage) corresponding to the difference between the voltage corresponding to the actual illuminance from the comparator 12 and the reference voltage. A current proportional to the magnitude of the voltage is output to the aiming lamp 4. In addition, 14 is a DC15V power supply, for example.
Thus, the analog voltage, that is, the illuminance of the aiming lamp 4 is gradually increased until the illuminance reaches 300 lux after the sighting lamp 4 is turned on, and when the illuminance reaches 300 lux, the state can be maintained. . Therefore, even if the aiming lamp 4 has individual differences or has deteriorated, the illuminance is automatically adjusted to be 300 lux every time it is turned on again.

Next, an embodiment of the X-ray fluoroscopic apparatus of the present invention will be described with reference to FIGS. 3 and 4.
In FIG. 3, the X-ray fluoroscopic apparatus includes a table 28 on which a subject 29 as a subject is placed, an X-ray tube 10 that emits X-rays toward the subject 29, and an X-ray tube, as is well known. It comprises a flat panel detector 22 as a line detection means, an aiming lamp 4 (see FIG. 1) and a collimator 1 for an X-ray fluoroscopic apparatus having two sets of movable leaves 5 and 6.
X-rays irradiated from the X-ray tube 10 pass through the subject 29 and enter the flat panel detector 22. The flat panel detector 22 outputs an image signal corresponding to the incident X-ray.

  As shown in FIG. 4, the X-ray fluoroscopic irradiation apparatus includes a control unit 20 that controls the entire apparatus, and a storage unit 21 that stores data during control. The control unit 20 is connected to the collimator 1 for the X-ray fluoroscopic apparatus shown in FIG. 1, which includes the reflecting mirror 3, the aiming lamp 4, and the two sets of movable leaves 5 and 6. The control unit 20 is connected to the keyboard 27, the hand switch 25, and the flat panel detector 22. Further, the control unit 20 is connected to the X-ray tube 10 via the X-ray tube control unit 23. Furthermore, the control unit 20 is connected to an image display unit 26 such as a CRT via the image processing unit 24.

  When X-ray imaging is started, first, the imaging position is confirmed by the X-ray fluoroscopic apparatus collimator 1. Specifically, by moving two sets (four sheets) of movable leaves 5 and 6 with the aiming lamp 4 (see FIG. 1) turned on, the subject 29 is irradiated with light, By confirming the irradiation region, the X-ray irradiation region is set. At this time, the sighting lamp 4 is automatically adjusted so that the illuminance is always 300 lux every time it is turned on, even if there is an individual difference or has deteriorated, and the sighting lamp 4 cannot be aimed when the lamp is turned on. In addition to avoiding unforeseen circumstances, it is possible to aim at a constant illuminance at all times, so that the fluoroscopic imaging position can be confirmed and set quickly and suitably.

When the setting of an appropriate fluoroscopic imaging position is completed, a signal is transmitted from the hand switch 25 to the control unit 20 by operating the hand switch 25, and an X-ray is transmitted from the X-ray tube 10 according to a command from the X-ray tube control unit 23. Irradiated.
X-rays irradiated from the X-ray tube 10 and passing through the subject 29 are detected by the flat panel detector 22. The detection value obtained by the flat panel detector 22 is input to the control unit 20, and the control unit 20 takes the image signal into the storage unit 21 and transmits the image signal to the image display unit 26 via the image processing unit 24. The image display unit 26 displays an X-ray fluoroscopic image according to the image signal.

DESCRIPTION OF SYMBOLS 1 Collimator 2 for X-ray fluoroscopic imaging devices 2 Leads 3 Reflection mirror 4 Aiming lamp 5, 6 Movable leaf 7 CdS photodetector 8 Case 10 X-ray tube 11 Reference voltage generation circuit 12 Comparator 13 Current control circuit 14 DC15V power supply 15 Illuminance control means 20 of X-ray fluoroscopic apparatus collimator 20 Control unit 21 Storage unit 22 Flat panel detector 23 X-ray tube control unit 24 Image processing unit 25 Hand switch 26 Image display unit 27 Keyboard 28 Table 29 Subject

Claims (3)

  An aiming lamp for irradiating the same area as the X-ray irradiation area with light, an illuminance detecting means for detecting the illuminance of the aiming lamp, and adjusting the illuminance of the aiming lamp according to the detection result of the illuminance detecting means An illuminance control unit, and the illuminance detection unit is disposed in a collimator at a position where light from the aiming lamp is irradiated and at a position where the X-ray irradiation region is not shielded. Collimator for fluoroscopic imaging equipment.   The collimator for an X-ray fluoroscopic apparatus according to claim 1, further comprising a leaf for narrowing the X-ray irradiation area, wherein the illuminance detection means is disposed on a surface of the leaf irradiated with light from the aiming lamp. A collimator for an X-ray fluoroscopic apparatus, characterized in that An X-ray tube for irradiating an X-ray toward the subject, an X-ray fluoroscopic apparatus collimator having an aiming lamp for irradiating the same region as the X-ray irradiation region, and the subject irradiated from the X-ray tube An X-ray fluoroscopic apparatus comprising: an X-ray detection unit that detects X-rays transmitted through the X-ray; and an image display unit that displays an X-ray fluoroscopic image based on an X-ray detection value by the X-ray detection unit.
As the X-ray fluoroscopic apparatus collimator, illuminance detection means for detecting the illuminance of the aiming lamp and illuminance control means for adjusting the illuminance of the aiming lamp according to the detection result of the illuminance detection means The illuminance detection means is disposed in a position where the light from the aiming lamp is irradiated inside the collimator for the X-ray fluoroscopic apparatus and is disposed at a position where the X-ray irradiation area is not shielded. An X-ray fluoroscopic apparatus comprising a collimator.

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