JPS5885687A - X-ray television device - Google Patents

Abstract

PURPOSE:To simplify an operation, and to prevent generation of halation, by detecting an outline part of a body to be inspected, from a television signal by an X-ray image, and making an aperture position of X-rays follow the outline part of the body to be inspected. CONSTITUTION:A titled device is provided with an automatic X-ray aperture controlling circuit 10 which detects an outline part of a body to be inspected 5 by a television signal from a television camera 7, and supplies a control signal to a driving circuit 3 when a position of an X-ray aperture 2 has been shifted from the outline part of an image of the body to be inspected 5, on a picture surface 9 of a monitor 8. Accordingly, the X-ray aperture is moved automatically by following a movement of the body to be inspected 5, halation is not generated, and monitoring can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray television blinding apparatus which is particularly suitable for medical use and is capable of displaying an X1m transmission image as a television image every time.

The technique of observing an integral (living body) by irradiating it with X-rays is widely used for medical diagnosis and non-destructive testing of various products, but on the other hand, the accompanying X-ray exposure of operators poses a major problem.

In order to solve this problem, an X-ray television apparatus that reproduces an X-ray transmitted image as a television image has come into practical use, and an example thereof is shown in FIG.

In the figure, 1 is an X-ray tube, 2 is an X-ray number switch, 3 is its drive device, 4 is a control switch, 5 is a subject (human body), and 6
is an image intensifier (called LI), ・7
8 is a television camera, 8 is a monitor, and 9 is an image reproduction surface of the monitor. Note that a is a perspective image, and b and b' are diaphragm images obtained by aperture J)2.

XII generated in the X-ray tube 1 passes through the human body 5 and becomes lTl6
The optical signal is photoelectrically converted and amplified and replayed optically (IK). This optical signal is captured by a television camera 7, becomes a television signal, and is reproduced as a transparent image a on an image reproduction surface 9 of a monitor 8.

Therefore, this monitor 8 can be used as the X-ray tube 1 or 1. If it is installed in a place away from I6 and television camera 7, or in a place where there is sufficient X-ray protection,
Diagnosis and testing sessions can be performed without being exposed to XII radiation.

However, in such a system for observing the transmission of dangerous Xl1l, 1. If the human body 5 is not present in the full field of view of the I6 or the television camera 7, it is directly exposed to the X-ray tube 1.

A bright elementary fluoroscopic area due to the +X-rays incident on the optical system 6 appears around the image of the human body 5, and this causes a halation on the monitor and the observation of the fluoroscopic image becomes a cause of this, as shown in Figure 1. A KX-ray diaphragm 2 is provided as in the device described above, and the diaphragm 2 is apertured around the fluoroscopy @a of the KL and monitor 8's image reproduction device 9 so that the Fixe is not irradiated to the part where the human body 5 is not present within the field of view. A statue of Shiyahei.

b’t- I try to make it.

Conventionally, the Xls aperture 2 can be moved arbitrarily within the field of view by a drive device 3, and a predetermined position around the JXII aperture 25 can be moved by operating a control switch 4f. I was moving it to parts.

Therefore, in the above-mentioned conventional technology, it is necessary to move the switch 4 during monitor operation and change the position of the X-ray diaphragm 2 depending on the movement of the human body 5 and the position of the fluoroscopic image a. 90 The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to enable the X-ray aperture to automatically follow the subject such as a human body without any special operation. An object of the present invention is to provide an X-ray television device that can be moved and monitored without causing any noise.

In order to achieve this objective, the present invention detects the outline of a subject such as a human body from a television signal based on an X-ray image, and automatically adjusts the position of the RX* aperture with respect to the outline of the subject. It is characterized by being made to follow.

Embodiments of the xlI television apparatus according to the present invention will be described below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention, which is a 10Fi automatic X-ray diaphragm p control circuit.Otherwise, the automatic x*lRn control circuit 10 is the same as the conventional example shown in FIG. The outline of the human body 5 is detected by the television signal from the monitor 8, and when the position of the X-ray number 2 deviates from the outline of the human body 5 on the i** plane 9 of the monitor 8, A control signal is supplied to the drive circuit 3. As a result, the movement of the human body 5 is automatically followed by the movement of the human body 5.
It works to prevent the occurrence of burrage by creating ↓.・Figure 3 shows an embodiment of the automatic X-ray number control circuit 16, in which 20 is a four-bus filter, 21 is a binarization circuit,
22 to 25 are inverting circuits, 26 is a D flip-flop, 2
7.28 is monostable multivibrator, 29-31 is N
AND gate, 32 is exclusive OR gate, 3
3 is a delay circuit, 34 is a rectifier circuit, 35 is a switch changeover circuit, 36 is a drive amplifier circuit, and 37.38- is a changeover switch.

Note that the drive device 3 is the same as in FIG. 2 and is represented as a motor.

Further, VIDEO is an input of a video signal from the television camera 7, and HD is an input of a horizontal drive signal.

Next, the operation of this embodiment will be explained with reference to the waveform diagram in FIG. Note that the numbers 101 to 119 in FIG. 4 represent the waveforms of the signals that appear in the portions where the same numbers are all shown in FIG. 3, respectively.

Video signal 101 supplied from television camera 7
The signal 102 from which high frequency components are removed by the Fi milli-pass filter 2 is input to the comparison circuit 21 and becomes a signal 103 which is binarized at a predetermined level. .

This binary signal 103 is converted into an inverted signal 4 by an inverting circuit 22.
104 is input to the trigger input T of the DI)y flip-flop 26.

On the other hand, the monostable multi-pipe relay 27, to which a time constant of about 1/2 of the horizontal scanning period H is given by a time constant circuit consisting of a resistor R1 and a capacitor CI, is supplied from the television camera 7. The Paves signal 106 is triggered by the horizontal drive signal 105 with a pulse width of approximately H/2! The signal is generated and supplied to the D input of the D flip 70 block 26 and one input of the NAND gates 29 and 30.

Therefore, from the Q output of this D grip flop 26,
In the first half of the horizontal scanning period, when the signal 104 rises, K"
Thereafter, when the signal 104 rises in the latter half of the horizontal scanning period, a signal 107 of "LNK" is obtained.

This signal 107t is applied to the other input of the NAND gate 29 to obtain the signal 108 at its output, which is further applied to the NAND gate 29.
If K is supplied to the other input of the D gate 30 to obtain a signal 109, this signal 109 is the first half from the falling edge of the horizontal drive signal 105 to about the 172nd part of the horizontal scanning period. When the video signal 101 falls below a predetermined level, the signal becomes V'L' for the period It and remains "H" for the remaining 90 periods.

Therefore, this signal 109 is supplied to a delay circuit 33 having a delay time of t-1 frames, and the signal 109 is delayed by one frame period to obtain a nine-delay signal 110, which is excluded from the delay circuit 33.
The signal 109 is supplied to one input of the sibu-OR gate 32, and the signal 109 is supplied to the other input. And this exclusive OR gate 32
The output signal 111 is smoothed by the rectifier circuit 34 to obtain a DC signal 112, which is amplified by the amplifier circuit 36 and then supplied to the motor 3.

Similarly, the signal 109t N from the NAND gate 30
At the same time, the delayed signal 110 from the -grinding circuit 33' is inverted by the inverting circuit 24, and the signal 113t is supplied to the other input of the NAND gate 31, and its output signal 114 is inverted. The inverted signal 115t in circuit 25 is supplied to monostable multivibrator 28 for triggering.

This monostable multivibrator 28 is retriggerable and is composed of a resistor R2 and a capacitor C2.
It is made to have a time constant slightly longer than the horizontal scanning period H by several circuits, and its output signal 116t is supplied to the switch switching circuit 35, which switches the switches 37 and 38 in the opposite direction to that shown. K.

Now, suppose that the human body 5 does not move between the 7 frame period and the previous frame period.In that case, the signals 109 and 110 have the same waveform, so the output of the exclusive OR gate 32 The signal 111 is up to the "L" level of 1], so the rectifier circuit 34
The output signal 112 of is 0.

Therefore, since no power is supplied to the motor 3, it remains stopped, and the X-ray number) 2 also remains stopped at that position.

! Furthermore, since the input signal 113 of the NAND gate 31 is a signal obtained by inverting the polarity of the signal 109, the output signal 114 remains "H", and therefore the inverting circuit 2
The output signal 115 of No. 5 remains at 1L".

Therefore, the monostable multivibrator 28 is not triggered, the output signal 116 remains 'L' ttK, and the switch 3
7.38 is the switching state 11 shown in the figure.

Next, assume that the human body 5 moves between the frame period and the previous frame period, and the signal 119 becomes 119' relative to the delayed signal 110 of the delay circuit 32.

Then, the exclusive OR gate 320 input becomes signals 110 and 119', and a mismatching portion i occurs in the waveforms of the two, so an output signal 111′ corresponding to the mismatching portion appears, which is sent to the rectifier circuit 34. Therefore, a signal 112' of level + is inputted to the amplifier circuit 36.

Also, at this time, the NAND gate 310 input signal 1
13 and 109' coincides with each other in each horizontal scanning period, and the next part appears, so the output signal 114'
is changed to the "L# level", and the monostable multivibrator 28 becomes "K" so that it is triggered every horizontal scanning period by the signal 115'.

As a result, the output signal 1 of the monostable multivibrator 28
Since '16' goes to the "H" level, the switch switching circuit 35 switches the switches 37 and 38 in the opposite direction from that shown.

Then, the motor 3 starts rotating the tube in a predetermined direction, moves the X-ray number 2t to follow the human body 5, and returns to the relationship between the signals 119 and 111 at a position K that matches the contour of the body 5. The motor 3 then stops and the switches 37 and 38 return to the illustrated switching positions.

Further, when the direction of movement of the human body 5 is opposite to that described above, the signal 110 one frame period before the signal 109' in the frame period becomes as shown in the fourth @.

Therefore, at this time as well, exclusive OR gate 3
The same point as in the above case is that a mismatch portion appears in the input signal 112 and the signal 112 becomes a level 10 signal.
At this time, since there is no part where the input signal 113 of the NAND gate 31 matches the signal 109#, its output signal 114 remains at the vIH" level, and the output signal 115 of the inverter 25 maintains the ttK level at the ML" level. However, the switches 37 and 38 are in the switching state shown in the figure.In this case, the motor 3 starts rotating in the opposite direction to that described above, and moves the XII diaphragm 2 body 5 in the direction in which it moved. It operates to follow the contour.

The above explanation is about the X-ray diaphragm K corresponding to the shielding image on the image reproduction surface 9 of the monitor 8, but the same applies to the X-ray diaphragm K corresponding to the shielding image b'. Furthermore, the configurations corresponding to this part are shown with dashed numbers in Figure 3], and these are the same as those without a dash, especially those enclosed by dashed lines in Figure 3. Since the parts are exactly the same, the detailed explanation 1l11 will be omitted, and only the different parts will be explained. At the same time, a signal 117 obtained by inverting the output signal 106' of the monostable multivibrator 270 by the inverting circuit 23 is supplied to the D input of the D flip-flop 26' to obtain a signal 11g, which is 't' NAND gate 29'. This NAN
A signal 119 is obtained at the output of the D gate 29'.

As is clear from FIG. 4, this signal 119 is horizontally When the video signal 101 falls below a predetermined level in the latter half of the scanning period, the signal becomes vlL''.

Therefore, like the signal 109, this signal 119 is processed in the area enclosed by the chain line in FIG. Bye.

Furthermore, in Jin's embodiment, since the subject is the human body 51, there is no particular explanation of the shading portion in the vertical direction within the field of view, but the automatic control of the XII strangulation in the vertical direction should be carried out in the same way. In this case, the input HD
The tube direct drive signal is input VD, the time constant tUt of the monostable multivibrator 22 is approximately 1/2 K of the direct scanning period, and the time constant of the monostable multivibrator 28 is slightly longer than the vertical scanning period. Just do it.

As explained above, according to the present invention, the position of the KXII diaphragm is automatically moved so as to approximately match the contour of the subject such as the human body, which is different from the prior art.

Except for the defective tube, the X is easy to operate and does not cause burrage damage! An I-television system can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing a conventional example of an X-ray television device, FIG. 2 is a schematic block diagram showing an embodiment of an XII television television device according to the present invention, and FIG. 3 is an automatic X-ray aperture control. A block diagram showing one embodiment of the circuit, and FIG. 4 is a waveform diagram for explaining its operation.

Claims (1)

[Claims] In an X-ray television device equipped with an means for generating a control signal, and means for controlling an aperture that is moved in a predetermined direction by the number of X-rays in response to the control signal; 10. A television device configured to automatically perform multiple movements.