JPS5936399B2 - X-ray fluoroscopy equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray fluoroscopic imaging apparatus having an automatic adjustment function for X-ray tube voltage.

In X-ray fluoroscopic imaging equipment, the brush of the autotransformer for imaging is adjusted to have a certain relationship with the film imaging X-ray tube voltage based on the fluoroscopic X-ray tube voltage during fluoroscopy. Conventionally, a method of automatically setting the

This is because the sensitivity of the film is lower than that of the X-ray imaging device, when the image received by the image intensifier X-ray imaging device is received by a TV camera and the same area is photographed on film as in fluoroscopy, which is displayed on a monitor. This is because the X-ray tube voltage must be increased.

First, a specific example of a conventional fluoroscopic photographing apparatus of this type will be described with reference to FIG.

In FIG. 1, 1 is an X-ray tube that emits X-rays using a high voltage from a high voltage transformer 25, 2 is a subject, 3 is a fluoroscopy table,
31 is a movable film, and 4 is an X-ray imaging device (image intensifier) that converts fluoroscopic X-rays into fluorescent images.
, 5 is a mirror having the function of transmitting the output light from the X-ray imaging device 4 and reflecting a part of it, 6 is a TV camera for photographing a subject image, 7 is a video amplifier, and 8 is an X-ray television device (hereinafter abbreviated as a monitor) and has a fluoroscopic imaging function.

Further, 9 is a fluorescent intensifier tube that detects and multiplies the light reflected by the mirror 5, 10 is a preamplifier, 11 is a variable resistor that sets a reference voltage according to the thickness of the subject, and 12 is the preamplifier 10. 13 is a servo amplifier, and 14 is its servo motor.

Reference numeral 15 denotes a fluoroscopic autotransformer having a movable brush 16, which constitutes a fluoroscopic imaging voltage control section.The brush 16 is moved by the drive of the servo motor 14, and the output of the transformer is used to switch between fluoroscopy and film imaging. It is input to the high voltage transformer 25 via the normally closed contact 24b of the relay 24, which is not shown.

Further, 17 is a voltage conversion circuit which inputs the voltage obtained through the brush 16 of the autotransformer 15 for fluoroscopy, and 18 is a voltage conversion circuit 23 that uses the output voltage and the brush 22 of the autotransformer 21 for photography. a comparison amplifier that compares and outputs the voltage obtained through the
is the servo amplifier for servo motor 20, and
The output voltage of the photographing autotransformer 21, which is variably set to 0, is input to the high voltage transformer 25 via the normally open contact 24a of the relay 24 (not shown).

According to the circuit configured as shown in Fig. 1, in the case of fluoroscopy, X-rays emitted from the X-ray tube 1 are absorbed by the subject 2, converted into a fluorescent image by the X-ray imaging device 4, and the fluorescent The image is transmitted through the mirror 5 and taken by a TV camera 6, and the image is observed as a transparent image on a monitor 8 via a video amplifier 7.

Further, the output fluorescent image of the X-ray imaging device 4 is reflected by a mirror 5 and guided to a fluorescence multiplier tube 9, and a preamplifier 10
The servo motor 14 is driven via the comparison amplifier 12 and the servo amplifier 13 so that the output electrical signal is the same as the reference voltage preset by the variable resistor 11. , transformer 1
The brush 16 of No. 5 is set to slide so that a predetermined voltage is obtained.

In this way, the output voltage of the autotransformer 15 for fluoroscopy is sent to the high voltage transformer 25 through the normally closed contact 24b of the switching relay 24 for fluoroscopy and film photography, and in addition to applying the fluoroscopy voltage to the X-ray tube 1, It is also used as a reference voltage for film photography.

That is, the output voltage of the autotransformer 15 for fluoroscopy is also used as the reference voltage of the drive circuit of the servo motor 20 that slides the brush 22 of the autotransformer 21 for film photography, and the tube voltage for fluoroscopy and photography is The servo motor 20 is driven so that the relationship as shown in FIG. 2 is achieved.

Through such operations, the fluoroscopic image is always kept at the optimum brightness, and the tube voltage for film imaging suitable for the fluoroscopic area can be automatically set during fluoroscopy.

However, such conventional devices still have the following points to be improved.

In other words, since the servo system that sets the tube voltage is connected to two series, one for fluoroscopy and one for film photography,
It takes a long time to set the optimal imaging tube voltage after the subject pressure changes, and when switching from fluoroscopy to snapshot imaging, X-rays are emitted while the transformer brush for film imaging is moving. Since the servo mechanism is locked to prevent the X-ray tube voltage from changing during imaging, the servo mechanism that slides the brush is locked before the optimal X-ray tube voltage is set. There were cases where

Furthermore, since two sets of servo amplifiers, servo motors, and autotransformers are required, the adjustment and circuit configuration thereof are complicated, and there is also an economical problem of high cost.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above, to provide an economically advantageous X-ray control device that always has the function of setting the optimal X-ray tube voltage.

The present invention focuses on the fact that there is a pause time of about 1 to 2 seconds to ensure the film movement time between fluoroscopy and film photography, and uses this period to make a single roll when taking film photography. The main feature is that it has a function to move the brush of the transformer and adjust it to the optimal tube voltage.It also moves the brush of the autotransformer and confirms that the specified tube voltage has been reached.
In addition, the autotransformer that adjusts the X-ray tube voltage is equipped with multiple taps, and these taps can be switched for fluoroscopy and film photography. The present invention is characterized in that an autotransformer is used in common, and that a microcomputer is used as means for calculating a predetermined camera tube voltage from the input voltage of the high voltage transformer.

Specific embodiments of the present invention are shown in FIGS. 3 and 4 and will be described in detail below.

FIG. 3 shows an example of this, and in the figure, the same reference numerals as in FIG. 1 have the same functions.

In FIG. 3, reference numeral 29 is an autotransformer used for adjusting the tube voltage for both fluoroscopy and film photography, and its brush 30 is slid by the servo motor 4.

The autotransformer 29 also has an intermediate tap a. b, c, d
, e are provided, and tap a is a voltage conversion circuit 17 for transparent viewing.
It is also connected to a high voltage transformer 25.

Taps b, c, d, and e are contacts I of relays IRY~4RY
They are connected in parallel via RYa to 4RYa and connected to a voltage conversion circuit 17' for film photography.

Note that the other input voltage of this voltage conversion circuit 17' is inputted from the sliding lily pad 30.

Reference numeral 26 denotes an arithmetic storage circuit, in which the output of the autotransformer 29 is converted through the voltage conversion circuit 17 into the relationship shown in FIG. 2, and is stored as an electrical signal corresponding to the camera tube voltage to be set. It is.

27 is a discrimination circuit, which includes an arithmetic storage circuit 26 and a voltage conversion circuit 1.
The output of 7' is used as input, and the voltage difference is set to such an extent that the servo motor 4 can adjust the tube voltage during the pause time (1 to 2 seconds to ensure the film movement time) between fluoroscopy and film photography. This is for constantly operating any one of relays IRY to 4RY during fluoroscopy.

Reference numeral 28 denotes a comparator that drives relay 5RY and outputs a tube voltage suitable for film shooting to high voltage transformer 25 when the film shooting tube voltage has reached a so-called predetermined film shooting tube voltage. It has an interlock function to confirm that the tube voltage is correct and not to emit X-rays until a predetermined tube voltage is reached.

Also, 24 a- to 24 a-a and 24b-1 to 2
Reference numeral 4b-6 indicates normally open and normally closed contacts of a relay 24 (not shown) for switching between fluoroscopy and film photography, which are inserted as shown.

Next, the operation of this circuit will be explained.

First, in fluoroscopy, the brush 3 of the autotransformer 29 is
0 is automatically adjusted.

At this time, the output of the autotransformer 29 is led to the arithmetic storage circuit 26 through the voltage conversion circuit 17 and the relay contact 24b-2, which is closed when viewed through, and is converted so as to have the relationship as shown in FIG. It is stored as an electrical signal that is equal to the imaging tube voltage.

This memory is updated at a fixed period, for example, every 10 cycles of the power supply.Meanwhile, the autotransformer 29 has a plurality of taps b,
c, d, and e are provided, and contacts IRYa to 4RYa of relays IRY to 4RY are connected to each tap, respectively. Therefore, the photographing tube voltage is the same as that of the voltage passed through the contact of any one of these relays. It is applied depending on the voltage between the tap and the brush 30.

The voltage between the brush 30 and the tap is led to the discrimination circuit 27 together with the output of the memory circuit 26 through the voltage conversion circuit 17' and the contact 24b-3, which is closed during transparent viewing.

The discrimination circuit 27 generates a voltage difference, for example 5K, that allows the servo motor 14 to adjust the tube voltage during the pause time (1 to 2 seconds) between the two electrical signals transitioning from fluoroscopy to film photography.
Any one of the relays IRY to 4RY is always operated during fluoroscopic imaging so that the voltage is about V.

In such a state, when the relay 24 (not shown) is switched to switch from fluoroscopy to film photography, the contacts 24a-2 and 24a-3 close in the comparison circuit 12, so that the output of the memory circuit 26 becomes the standard. The output of the voltage conversion circuit 17' is led to the other terminal, and the servo motor 14 is driven to operate the brush 30 so as to obtain a proper film tube voltage.

When the camera tube voltage becomes appropriate, the comparator 28 operates to drive the relay 5RY and apply the appropriate film tube voltage to the X-ray tube 1 via its contact 5RYa and the already closed contact 24a-. The image of the subject is photographed on the film 30.

FIG. 4 shows another embodiment of the present invention. In the embodiment described above, an arithmetic storage circuit or the like is used as a means for calculating the numerically indicated camera tube voltage from the input voltage of the high voltage transformer. However, in the non-embodiment, this is processed by a microcomputer.

Also in FIG. 4, the same reference numerals as in FIGS. 1 and 3 described above have the same functions.

As shown in the figure, a multi-input, single-output multiplexer 32t A/D whose output is the output of the preamplifier 10 is used.
The converter 33 includes, for example, an 8080 microprocessor and memory circuits (RAM).

A computer (CPV) mainly configured with ROM) etc.
34 and a buffer memory 35 for temporarily storing signals from the computer 34, etc., are connected as shown in the figure.

According to this circuit configuration, the output signal of the preamplifier 10 and the output signal of the voltage conversion circuit 17'' are each converted into a digital value by the A/D converter 33 via the multiplexer 32, and the digital value and the output signal in the computer 34 are converted into digital values. A computer 34 performs arithmetic processing using data for calculating the camera tube voltage previously stored in the ROM, and the arithmetic processing data is input to a buffer memory 35, and as in the embodiment shown in FIG. 3, the servo amplifier 13 , the servo motor 14 is driven or IRY to 5RY are driven to output the optimum tube voltage.

As is clear from the above examples, in the present invention,
One autotransformer is used to adjust the optimal tube voltage for film photography during the X-ray pause period when switching from transparent photography to film photography.

Therefore, it takes only a short time from fluoroscopy to setting the optimum film tube voltage, and there is no possibility that the servo mechanism will be locked during the process.

Furthermore, since one set of servo mechanisms and one autotransformer are used to set the tube voltage during fluoroscopy and film photography, the adjustment and circuit configuration are simplified, and the economical effect is extremely large.

[Brief explanation of the drawing]

Figure 1 is an overall block diagram of a conventional X-ray fluoroscopic imaging device.
Fig. 2 is a correlation diagram of tube voltages for fluoroscopy and film photography, Fig. 3 is an overall block diagram of an X-ray fluoroscopic imaging apparatus showing one embodiment of the present invention, and Fig. 4 is a diagram showing another embodiment of the present invention. FIG. 2 is an overall block diagram illustrating. 1...X-ray tube, 2...subject, 3...
...Transmission table, 4...X-ray imaging device, 5...
...Mirror, 6...TV camera, 7...
...Video amplifier, 8...X-ray television equipment,
9... Fluorescence multiplier tube, 10... Preamplifier, 11... Variable resistor, 12, 28...
...Comparator, 13... Servo amplifier, 14...
...Servo motor, 17, 17', 17"・
...Voltage conversion circuit, 24a-i to 24a a,
24b t~24b st 5RYa...
Relay contact, 25... High voltage converter, 26...
... Arithmetic storage circuit, 27 ... Discrimination circuit, 2
9...Auto transformer, 30...Brush, 3
1...Film, IRY~5RY...
Relay, 32...Multiplexer, 33...
... A/D converter, 34 ... Computer, 3
5...Buffer memory.

Claims (1)

[Scope of Claims] 1. High voltage generation that takes in input voltage for fluoroscopy input from an input terminal during fluoroscopy and generates high voltage for fluoroscopy, and generates high voltage for photography by taking input voltage for photography input from an input terminal during imaging. During fluoroscopy, the high voltage for fluoroscopy of the high voltage generator is input and X-rays for fluoroscopy are emitted, and during imaging, the high voltage for imaging of the high voltage generator is input and the X-rays for radiography are emitted. an X-ray tube, a switchable first tap, and a second tap provided to extract voltage between the first tap during fluoroscopy;
an autotransformer comprising a third tap provided to take out voltage between the first tap during imaging, and a third tap provided to take out voltage between the first tap and the second tap during fluoroscopy; is supplied to the high voltage generator as the input voltage for fluoroscopy, and during imaging, the voltage between the first and third taps is supplied to the high voltage generator as the input voltage for imaging via the input terminal. a first means for supplying the fluoroscopy X-rays to the X-ray tube; and a means for switching the first tap according to the deviation from the fluoroscopic voltage, and obtaining the voltage between the first and second taps of the autotransformer during fluoroscopy to obtain a voltage for imaging corresponding to the fluoroscopy voltage. , a memory circuit for storing a reference voltage for imaging, and a voltage between the first and third taps at the time of imaging after completion of fluoroscopy, so that the voltage between the stored reference voltage for imaging becomes the stored reference voltage for imaging;
A second tap that switches the first tap according to the deviation between the voltage between the first and third taps and the photographing reference voltage.
An X-ray fluoroscopic imaging device comprising: 2. Until the voltage between the first and third taps in the second means reaches the photographing reference voltage, the voltage between the first and third taps is connected to the input terminal of the high voltage generator. An X-ray fluoroscopic imaging apparatus according to claim 1, wherein the X-ray fluoroscopic imaging apparatus is configured such that no voltage is applied. 3. A microcontroller as means for calculating a predetermined camera tube voltage from the input voltage of the autotransformer. Claim 1 characterized in that a computer is used.
The X-ray fluoroscopic imaging device described in Section 1.