JPS5914840A - Radioactive ray photographic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a radiographic apparatus that can minimize the radiation dose given to a subject and reduce the burden on the heart, for example in cardiac volume measurement, etc. be.

[Technical background of the invention]

Conventionally, for example, when measuring ventricular volume as part of a cardiovascular system test, radiation was irradiated and images were taken regardless of the ventricular systole or diastole, so the maximum ventricular diastole required for the test was The subjects were exposed to radiation and photographed even at times other than the minimum reduction, so subjects were exposed to more radiation than necessary and the amount of film required for photography was enormous.

In addition, X-ray contrast method using contrast agent injection is used to image the heart, but since the ting for injecting the contrast agent into the ventricle must be aligned with the imaging tie ink 1, in the case of the above-mentioned method, the movement of the ventricle is Contrast media will be injected regardless of the condition, and since the blood volume in the ventricles is low during the ventricular contraction stage, depending on the amount of contrast media injected, the human body may be at risk and intraventricular pressure may also increase. , the contrast agent injection device also operates under a large pressure burden.

Therefore, a method of performing X-ray photography based on an electrocardiogram has also been proposed. However, in such cases, the relationship between the ECG waveform and ventricular expansion and contraction is such that although the maximum point of ventricular volume corresponds to the S wave on the ECG, the minimum point of ventricular volume is after the T wave. It has been difficult to determine the minimum cardiac volume point from the p1 electrocardiogram waveform due to individual differences.

[Purpose of the invention]

The present invention was developed in view of the above circumstances, and it minimizes the amount of radiation exposure when measuring p1 ventricular volume, reduces the burden on the heart due to the injection of contrast media, etc., and also significantly reduces the amount of film used. It is an object of the present invention to provide a radiographic apparatus that can reduce the amount of radiation.

[Summary of the invention]

That is, in order to achieve the above object, the present invention provides a means for shaping a cardiac sound waveform to obtain a pulse synchronized with the heart sound, a means for obtaining a signal corresponding to the diastolic phase of the ventricle from the obtained 9 pulses, and (a means for injecting a contrast agent controlled by the obtained signal, and a means for performing X-ray photography in response to the above-mentioned arm) to obtain pulses synchronized with heart sounds and cardiac movements, and to The circulatory system is imaged using radiation such as X-rays in response to pulses, and since the diastolic period of the ventricle is shorter than the next systolic period in the generation cycle of heart sounds caused by the movement of ventricular expansion and contraction,・Diastole can be easily detected by using the fact that diastole can be easily detected compared to frus, and contrast agent injection can be performed to ensure the safety of the subject and to allow imaging at maximum and minimum dilation of the ventricle. This enables efficient and accurate inspection.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a professional diagram showing the schematic configuration of this device; 1 in the figure is a cardiac sound waveform shaping device that amplifies the heart waveform signal, limits the band, extracts it, shapes the waveform, and outputs it;
JJ is an X-ray imaging device drive device that controls X-ray imaging in response to the output/f pulse of this heart wave shape shaping device 1; 18 is an X-ray imaging device drive device that is controlled by the output of this X-ray imaging device drive device 12; The X-ray imaging device 14 receives the pulse output from the heart sound waveform shaping device foIJ and determines whether this pulse is the first or second heart sound. and a first sound/second sound discrimination circuit that outputs a judgment output.
Reference numeral 5 denotes a contrast medium injection device which operates upon receiving a determination signal indicating that the sound is between the second sound and the first sound output by the first sound/second sound discrimination circuit 14, and injects a contrast medium into the subject. 16, and a contrast medium injection device 16.

With this device having such a configuration, the heart waveform signal extracted from the subject, which is not shown in FIG. After being amplified, it is shaped into a rectangular wave and output as a pulse representing the heart sound.

The details are shown in FIG.

FIG. 2 shows the specific circuit configuration of the cardiac waveform shaping device 11, which includes a band-limiting amplifier 21, a detection diode 22, an integrating capacitor 23, and a Schmitt trigger type 5-inverter 24 for waveform shaping. , 215 as shown in the figure. The heart waveform shaping device 1 with such a configuration is
The derived heart sound waveform is first input to the first-stage band-limiting amplifier 21 via a coupling capacitor, where the frequency band components of the heart sound are amplified, and only the heart sound is amplified. This amplified output is subjected to p half-wave rectification by a diode 22 in the next stage, which is a rectifier circuit, and charges a capacitor 23. When the potential of capacitor 23 exceeds a certain value, 1
! 4,25 shi! , one shaped rectangular wave is generated by the trigger type in-tweeter. This output is generated in synchronization with the first and second heart sounds.

In this way, the heart waveform shaping device 1 outputs a rectangular wave (ie, a pulse) in response to the heart sound. Therefore,
This rectangular wave is generated in synchronization with the first and second heart sounds.

This situation is shown in FIG. 4 a+b. In the figure, the pulse train synchronized with the heart sounds output from the heart sound waveform shaping device 11 thus obtained is input to the first sound/second sound discriminating circuit 14 and the XM imaging device driving device 12, respectively. The first sound/second sound discrimination circuit 14 uses the fact that the interval between the first heart sound and the second heart sound is sufficiently shorter than the interval between the second heart sound and the next first heart sound to distinguish between the three heart sounds. conduct.

The details are shown in FIG.

FIG. 3 shows a specific example of the circuit configuration of the first tone/second tone discriminating circuit 14.
, a monostable multivibrator circuit 32, and a JK flip-flop circuit 34 as shown in the figure.

That is, the first sound/second sound discriminating circuit 14 is made monostable by the output of the AND/DART circuit 31 which takes the AND logic of the rectangular wave pulse output from the cardiac waveform shaping device 11 and the Q output of the monostable multi-pie break circuit 32. Multi pie break circuit 3
2 operates, and is also shifted by the Q output of the monostable multivibrator circuit 32, and takes AND logic with the Q output of this monostable multivibrator circuit 32 and the output pulse of the cardiac sound wave shaping device 1. AND gate circuit 3
The JK Afrinoflo 2 circuit 34 whose terminal is set to the logic level °'1'' is operated by the output of 3, and the q output is configured to be the discrimination output.
It is possible to detect the period from the generation of a sound until the generation of the next first sound.

That is, in this device, the JK flip-flop circuit 34 in which the monostable multi-iJ ibrator 32 is connected is maintained in a reset state because there is no input of the 4 pulses in normal times, so the Q output of the JK flip-flop circuit 34 is maintained in a reset state. is at logic level ``1#.'' In this state, the heart wave shaping device 11
When the above-mentioned pulse train from
A trigger pulse is applied to the monostable multivibrator circuit 32 through this.

Here, the width of the Q output of the monostable multivibrator circuit 32 is longer than the interval between the first tone and the second tone, and the interval between the second tone and the next first tone, as shown in FIG. 4(c). Keep it short.

In this way, for example, considering the point in time when the monostable multivibrator circuit 32 is triggered by a nof pulse synchronized with the first tone, the monostable multivibrator circuit 32 is activated when a pulse synchronized with the second tone is generated. Q output of 32 is still at logic level MO#, so AND? −)
There is no risk of bringing the circuit 31 to logic level "l#" and therefore the monostable multivibrator circuit 32 will not be retriggered. Conversely, the monostable multivibrator circuit 3 will not be retriggered.
2 is triggered by a pulse synchronized with the second tone, the Q output of the monostable multivibrator circuit 32 is already at the logic level ``'1'' when the next pulse synchronized with the first tone occurs. This ensures that the monostable multivibrator circuit 32 is triggered each time by a pulse synchronized with the first tone.

Here, the Q output of the monostable multivibrator circuit 32 exhibits a change as shown in (cl) in FIG.

Therefore, for each f pulse input, this human power if This output is input to the JK Afri f Florazo circuit 34, which alternately sets and resets the JK Frizzo 7μ horn circuit 34.

As a result, the output of the JK flip-flop circuit 34 becomes as shown in (dl in FIG. 4.)
2. The alternating output d of the circuit 34 has a logic level of 1'07 between the first and second notes, and a logic level of ``12'' between the second note p and the next first note.

Conventionally, when a contrast agent or the like is injected into the ventricle 10- using a catheter or the like, the injection is forcibly performed from outside, regardless of the diastole or systole of the heart. In this case, injecting a contrast agent while the ventricle is contracting puts a strain on the subject's heart, which poses safety issues, and also has drawbacks such as the tendency to increase the injection pressure of the injection device. was occurring.

Therefore, in the apparatus of the present invention, in order to selectively inject a contrast agent or the like during the diastolic phase of the ventricle, the injection is controlled using the output of the JK Frizzoflo circuit 34 shown in FIG. That is, between the second sound corresponding to the diastolic phase of the ventricle and the next first sound, as described above, the Q output of the JK Afri f Frozzo circuit 34 is at the logic level "1111," so this signal is used for injection. If used for control, the burden on the subject and the injection device can be reduced.

Therefore, the same output (FIG. 4(d)) is applied to the contrast medium injection device driving device J5i7m to control it, thereby driving the contrast medium injection device 16 during ventricular diastole to inject the contrast medium. conduct. FIG. 4 (@) shows how the amount of contrast medium injected by this apparatus changes. This reduces the burden on the subject and ensures greater safety for the human body during cardiac examinations.In addition, since contrast medium injection is performed during a period when ventricular pressure is low, the contrast medium injection device 16 is mechanically This reduces the burden on users and extends the life of the equipment.

In order to drive the device for taking images of the contrast medium injected by the method described above, a pulse train synchronized with the heart sounds shown in Fig. 4, which are signals indicating the end of systole and end of diastole of the ventricle, is required. use That is, the Xa imaging device driving device 12 is driven in response to the pulses of this heart sound f pulse train, thereby controlling the X-ray imaging device 13.

As a result, the X-ray imaging device 13 performs X-ray exposure every time the f pulse is input, and imaging proceeds. With this method, imaging is performed in synchronization with the movement of the ventricle. This allows you to obtain photographs of the ventricles during expansion and contraction, which are useful for diagnosis, and reduces the number of radiographs needed because there are no unnecessary photographs compared to the conventional method of taking images at regular intervals regardless of ventricular expansion and contraction. This makes it possible to save a great deal of energy (9), and it also greatly contributes to reducing the amount of X-ray exposure to subjects and the number of films to be photographed.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, and can be modified in various ways without changing the gist of the invention. As shown in FIG.
Alternatively, as shown in FIG. 6, when injecting a contrast medium or simultaneously measuring intraventricular pressure, it is possible to obtain the information by attaching it to the chest of the subject P through a blood vessel 60. It is also possible to obtain the heart sound by extracting a frequency component corresponding to the heart sound from the intraventricular pressure obtained from the catheter 62 set inside the heart.

Further, the present invention is effective not only for measuring ventricular volume but also for radiation measurement of phenomena that occur in synchronization with heartbeats. For example, since movement of blood within a blood vessel is caused by contraction of the ventricle, if a contrast agent is injected into the ventricle using a catheter and an angiographic image is taken with each heartbeat using the method of the present invention. Abnormalities such as vascular stenosis can be detected from the movement of blood pumped out by a single contraction of the ventricle.

〔Effect of the invention〕

As described in detail above, the present invention shapes the heart waveform and synchronizes it with the heart sounds. a means for obtaining a signal corresponding to the diastolic phase of the ventricle from the obtained signal; a means for injecting a contrast medium controlled by the obtained signal; This is a means to perform XM photography in response to Luz.
The system is configured to obtain pulses synchronized with the heart sounds and heart motion, and to perform X-ray photography in response to the pulses.
4. Since the diastole phase of the ventricle can be easily detected, the diastole phase is detected, and the ↓p contrast agent is injected into this detection output, so the contrast agent injection is safe for the human body. In addition, it can be performed in conjunction with the 14-diastole phase when the pressure is low, making it possible to perform highly safe tests. Photographs and data are obtained when the ventricle is at maximum expansion and minimum contraction, and therefore,
Since unnecessary imaging is not performed as in the past, it is possible to significantly reduce the radiation dose given to the subject, reduce the amount of film used for imaging, and reduce the burden on the heart during contrast medium injection. It is possible to provide a radiation imaging apparatus for testing the circulatory system that is safe and has low running costs, such as being able to perform accurate tests.

[Brief explanation of drawings]

FIG. 1 is a system block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a heart wave shaping device 11 in FIG. 1.
Figure 31 is a circuit diagram showing the configuration of a specific example of the first sound in Figure 1! A circuit diagram showing a specific example of the second sound discrimination device 13, FIG. 4 is a timing chart showing the operation of this device,
FIGS. 5 and 6 are diagrams for explaining an example of picking up heart sounds. 1 No.. Cardiac sound wave shaping device, 12.. Xi imaging device drive device, 13.. X-ray imaging device, J4.. 1st sound/2nd sound discrimination circuit, 15.. Contrast medium injection Device driving device, 16... Contrast medium injection device, 2... Band-limiting amplifier, 22... Diode, 23... Capacitor, 2
4.26...shi, <, totrigger type inno (-ta, 31
...and dart circuit, 32...monostable multi-pie break circuit, 33...and r-) circuit, 34...
・JK Frizzoflo, 1 circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 5 Figure 6

Claims (1)

[Claims] A means for obtaining a pulse synchronized with the heart sound from a heart sound waveform obtained from the subject, a means for obtaining a signal corresponding to the diastole phase of the p ventricle from this pulse, and a contrast agent injected into the subject's circulatory system under the control of the obtained signal. A radiographic apparatus comprising: means for performing injection; and means for performing radiographic imaging of a subject's circulatory system in response to the nofrus.