JPH0199530A - Electrocardiography system - Google Patents

Abstract

PURPOSE:To prevent the mutual obstruction between an imaging device and a differential electrode by providing a plurality of differential electrodes of electrocardiograph for the purpose of sampling heart beat signals on regions other than the one where images of image-diagnosis for various medical treatment are displayed or photographed. CONSTITUTION:An LL defferential electrode 3 and a RL differential electrode 4 are connected to a differential amplifier 7 of an electrocardiograph 6 as a differential voltage input, while an indifferent electrode 5 is grounded 8 as a reference ground of the cardiograph 6. Out of those electrocardiographic signals which has been amplified by the differential amplifier 7 and signal- treated by the cardiograph 6, only the heart beat signals to represent heart beat action generate trigger signals from a trigger generator 10 of an imaging device 9 and actuate the imaging device 9. In this case, the imaging region 2 of a test specimen 1 is normally an organ located above a hip or a head part, thereby both the LL differential electrode 3 and the RL differential electrode 4 are positioned distant apart from the imaging region 2, therefore, are hardly affected even by a strong RF magnetic field or an X-rays.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applicable to the purpose of generating a heartbeat trigger for various medical timbre imaging devices that perform heartbeat-synchronized imaging or post-edit data editing with reference to heartbeats. Regarding the electrocardiogram system used.

(Conventional technology) Magnetic Resonance Imaging Device (hereinafter referred to as MRI).

When observing and diagnosing the heart using tomographic images using medical image diagnostic equipment (hereinafter referred to as imaging equipment) such as X-ray IIFi layer imaging equipment (hereinafter referred to as X-ray CT) and ultrasound diagnostic equipment, Since image display or image capture (hereinafter referred to as imaging) is performed, the obtained image is a mixed image of systole and diastole, and details are not clearly depicted. Therefore, in order to obtain clear tomographic images of the heart,
So-called heart rate synchronized photography, which takes images in synchronization with the heartbeat,
A method of editing data after the fact by referring to the heartbeat is used, and the trigger that controls the transmission of the imaging device is synchronized with the QR8 complex of the electrocardiogram waveform obtained from the electrocardiogram system using the above method. is occurring. This is true not only in the case of cardiac imaging but also in the case of tissue fibers including blood vessels. The induction method used in this electrocardiogram system is the same as that for ordinary electrocardiograms.

An electrocardiogram is a record of the temporal changes in weak electricity generated in response to the rhythmic movement of the heart through the combination of two electrodes. This electrical phenomenon is amplified by a differential amplifier by selecting two points on the body surface or inside the body, and the potential difference is recorded. Various induction methods can be considered depending on how the two points are selected. Among these, induction from within the body is a special case, and generally a method of induction from the body surface is used, and the induction method currently used is as shown in FIG. These electrocardiogram recording techniques have also been adopted in the electrocardiogram system guidance method for heart rate synchronized imaging using the first lead and the second lead shown in FIG. In other words, an ordinary electrocardiograph was used according to its specifications.

(Problems to be Solved by the Invention) For example, if lead I is used, electrodes must be attached to the right and left hands, or alternatively to the right and left shoulders, but in that method, the original MRI + XIC
In addition to being a hindrance to T, especially in the case of MRI, when an electrode wire is passed through a location where a high-level radio-frequency magnetic field is applied, a high-frequency current flows through the wire and a strong current flows through the electrode to the patient. . In addition, there are problems such as a large high-frequency current flowing into the electrocardiograph amplifier and potentially destroying the first-stage amplifier, and the high-frequency trap to solve this problem is a short-wave transmitter with a kilowatt-class output. It is quite troublesome as it requires something that can coexist. The same is true for standard limb leads other than lead I and unipolar limb leads, in which both hands or hands and feet are used, and the imaging device images the upper part of the body, including the lumbar region. Since most of them are, similar problems occur.

The present invention has been made in view of the above points, and its purpose is to obtain electrocardiographic signals without interfering with the original purpose of imaging the upper part of the body, including the lumbar region, and without being affected by said imaging. The object of the present invention is to realize an electrocardiogram system that can collect electrocardiograms and cause an imaging device to perform a heartbeat-synchronized dance.

(Means for Solving the Problems) The present invention solves the above-mentioned problems by providing a method for generating a heartbeat trigger in various medical image diagnostic devices that perform data editing using a heartbeat synchronized image or a heartbeat signal as a reference signal. In an electrocardiographic system that collects heartbeat signals using electrocardiographs, a plurality of electrocardiographs are used to collect heartbeat signals outside the image display or image capturing area of the various medical image diagnostic devices. It is characterized by attaching NIm poles.

(Function) Since the heartbeat signal is collected by the electrode attached outside the imaging area of the imaging device, there is no mutual interference between the imaging device and the intercalary electrode.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of the present invention.

In the figure, 1 is a subject to be imaged by an imaging device, and 2 is a region in which the imaging device images the subject 1, and for example, in the case of MRI, this is a region to which a high-frequency magnetic field is applied.

3 is the LL attached to the left leg to collect biological signals
Separate electrode, 4, is the RLII attached to the right leg for the same purpose.
The Im pole, 5, is the non-1 [pole that is attached to the right foot or for taking the friend's ground.

LL main electrode 3RLl! The I electric field 4 is connected to a differential amplifier 7 of an electrocardiograph 6 as a differential voltage input, and the indifferent electrode 5 is connected to a ground 8 as a reference ground of the electrocardiograph 6. Among the electrocardiographic signals amplified by the differential amplifier 7 and signal-processed by the electrocardiograph 6, a heartbeat signal for transmitting heart beats is sent to the trigger generation circuit 10 of the imaging device 9.
A trigger signal is generated from the camera to operate the imaging device [9].

It is assumed that the electrocardiograph 6 and the imaging device @10 are electrically separated from each other by, for example, using a photocoupler to maintain safety for the living body.

Next, the operation of the embodiment configured as above will be explained. The guidance method for electrocardiogram measurement is as shown in Figure 2. In all methods, the measurement points are selected so that the line connecting the two measurement points passes close to the heart, allowing the electrocardiogram signal to be detected with high sensitivity. However, as shown in the example, even if the left and right foot leads are selected, there is almost no change in the waveform, and the output voltage is only about 115 to 1/10 of that of lead I. be. This is the left leg LLf! II pole 3
The relationship between the RL electrode 4 of the right foot and the L of the left hand in lead T
Since the relationship between the A electrode and the RA electrode on the right hand and the position with respect to the heart are almost the same, and the only difference is the distance, the waveforms are considered to be the same, so even if the output is small, an electrocardiogram may be drawn. Instead, the trigger generating circuit 10 is simply excited by the QR8 complex of the electrocardiogram waveform, and other small changes are not observed, so it can be used even if the S/N ratio is somewhat degraded. FIG. 3 shows an example of an electrocardiogram waveform.

(A) The figure shows the waveform of the first conductor, which is drawn at 111v/Cl11, and the peak value is about 1.2mV. (b) The figure shows the waveform induced between the sole of the left foot and the sole of the right foot at 100 μV/cm.
The peak value is approximately 70 to 75 .mu.m, which is 1/16 to 1/17 of the former, but the waveforms are very similar. Even if you choose the farthest point from the heart, like the sole of the foot, it will be the third point.
As shown in the figure, it can be seen that the QR8 group is sufficiently usable. The electrocardiographic signals extracted by the LL electrode 3 and the RLf11I electrode 4 are amplified by the differential amplifier 7 of the electrocardiograph 6. The indifferent electrode 5 connected to the ground 8 is usually the right leg that is farthest from the heart, and this embodiment follows this practice, but it is not used in practice. The output signal of the QR8 wave from the electrocardiograph 6 is input to the trigger generation circuit 10 of the imaging device 9, which causes the transmitting section of the imaging device 9 to output a trigger signal for generating a transmission wave. In this case, the imaging region 2 of the subject 1 is usually the internal organs above the waist or the head, and the LLfA electrode 3 and the RL electrode 4 are both far away from the imaging region 2, and cannot be affected by the strong RFla field. , and is hardly affected by X-rays. Furthermore, it does not interfere with the transmission of X-rays or the high frequency magnetic field of MRI.

As explained above, according to this embodiment, by simply increasing the gain and changing the electrode arrangement using a conventional electrocardiograph, the imaging by the imaging device is not obstructed (and the imaging device is not interfered with). It is possible to realize an electrocardiographic system that is not affected.

Note that the present invention is not limited to the above embodiments.

For example, we explained by attaching the related electrodes to the right and left legs, but as long as they are out of the field of view of the imaging device, there will be no big difference in the waveform no matter where you choose them, and you can freely change the attachment positions. can. Further, the electrocardiograph and the imaging device may be connected by a telemeter. Further, the reference ground may be a driven ground that drives the indifferent electrode with the average of the related electrodes.

(Effects of the Invention) As described above in detail, according to the present invention, a trigger for transmission of an imaging device can be generated by a heartbeat signal without interfering with or being influenced by the original imaging. This has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of a conventional electrocardiogram guidance method, and FIG. 3 is a comparison diagram of electrocardiogram waveforms. 1... Subject 2... Imaging device 3
...LL related electrode 4...RLI'll electrode 5.
... Indifferent electrode 6 ... Electrocardiograph 7 ... Differential amplifier 8 ... Ground 9 ... Imaging device 10 ... Trigger generation circuit

Claims (1)

[Claims] In an electrocardiogram system that collects heartbeat signals using an electrocardiograph in order to generate a heartbeat trigger in various medical image diagnostic devices that perform heartbeat synchronized imaging or data editing using heartbeat signals as reference signals, the various medical images described above are used. An electrocardiograph system characterized in that a plurality of interest electrodes of the electrocardiograph for collecting heartbeat signals are attached outside an area where an image is displayed or imaged by a diagnostic device.