JP2009240623A - Pacemaker pulse detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection precision of a pacemaker pulse without increasing the number of electrocardiograph electrodes to use. <P>SOLUTION: Connection parts 102a, 102b, and 102c are connected to an electrocardiograph electrode 12a which is not a neutral electrode, an electrocardiograph electrode 12b which is not a neutral electrode, and an electrocardiograph electrode 12c which is a neutral electrode. A pacemaker pulse amplifier 106a performs differential amplification between a signal from the electrocardiograph electrode 12a and a signal from the electrocardiograph electrode 12b, a pacemaker pulse amplifier 106b performs differential amplification between a signal from the electrocardiograph electrode 12a and a signal from the electrocardiograph electrode 12c, and a pacemaker pulse amplifier 106c performs differential amplification between a signal from the electrocardiograph electrode 12b and a signal from the electrocardiograph electrode 12c. Pacemaker pulse detectors 108a to 108c detect pace pulses from signals inputted from the pacemaker pulse amplifiers 106a to 106c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pacemaker pulse detection device that detects a pacemaker pulse emitted from a cardiac pacemaker.

  When measuring an electrocardiogram from a patient implanted with a cardiac pacemaker (hereinafter simply referred to as a “pacemaker”), it is necessary to perform an electrocardiogram analysis by identifying the pacemaker pulse emitted from the pacemaker in the patient's body and the electrocardiogram waveform. is there. For this reason, the pacemaker pulse detection is simultaneously performed using the electrocardiographic electrode attached to the patient (see, for example, FIG. 5 of Patent Document 1). Therefore, in order to obtain an accurate electrocardiogram analysis result, it is required to perform pacemaker pulse detection with high accuracy.

  In general, there are pacemakers having a monopolar (monopolar) pacemaker lead and those having a bipolar (bipolar) pacemaker lead. In the bipolar type, the stimulation pulse is output between the two electrodes at the tip of the pacemaker lead, so the amplitude of the pacemaker pulse detected on the body surface is smaller than in the case of the monopolar type, ensuring a certain detection accuracy. It becomes difficult. Further, in the case of the bipolar type, the amplitude of the pacemaker pulse detected on the body surface greatly depends on the placement direction of the tip of the pacemaker lead.

  For example, as shown in FIG. 3A, the electrical relative angle between the stimulation electrode portion 2 of the bipolar pacemaker lead 1 and the pair of electrocardiographic electrodes 4a and 4b on the body surface of the living body 3 is substantially parallel. Thus, when the pacemaker lead 1 is placed, there is a distance difference between the electrocardiogram electrode 4a and the two stimulation electrodes 2a and 2b, and the electrocardiogram electrode 4b and the two stimulation electrodes 2a and 2b Since there is a distance difference between them, a potential difference is generated between the electrocardiographic electrodes 4a and 4b. In this case, it is relatively easy to accurately detect the pacemaker pulse in the output signal 6a of the differential amplifier 5. On the other hand, for example, as shown in FIG. 3B, the pacemaker lead 1 is arranged so that the electrical relative angle between the stimulation electrode portion 2 of the pacemaker lead 1 and the pair of electrocardiographic electrodes 4a and 4b is substantially perpendicular. When it is indwelled, there is no difference in the distance, and therefore no potential difference occurs between the electrocardiographic electrodes 4a and 4b. In this case, it becomes difficult to accurately detect the pacemaker pulse in the output signal 6b of the differential amplifier 5.

That is, the pacemaker pulse detection device is required to have performance capable of preventing the pacemaker pulse from being overlooked even in the situation shown in FIG.
JP-A-10-165383

  As described above, in the situation shown in FIG. 3B, it is difficult to accurately detect the pacemaker pulse. As a solution to this, it is conceivable to change the mounting position of the electrocardiogram electrodes or switch the electrocardiogram guidance. However, in this case, the electrocardiogram waveform also changes, and there is a possibility that accurate analysis cannot be performed in the electrocardiogram analysis. Another solution is to use a larger number of electrocardiographic electrodes. However, despite the fact that ECG can be measured from a patient with a small number of ECG electrodes, adding several ECG electrodes only for accurate detection of pacemaker pulses is detrimental to healthcare professionals and patients It is also inconvenient.

  The present invention has been made in view of this point, and an object of the present invention is to provide a pacemaker pulse detection device capable of improving the detection accuracy of pacemaker pulses without increasing the number of electrocardiographic electrodes to be used.

  The pacemaker pulse detection device of the present invention includes a first electrocardiogram electrode that is not a dead electrode, a second electrocardiogram electrode that is not a dead electrode, and an electrode connection unit that is connected to the third electrocardiogram electrode that is a dead electrode. , Differential amplification of the signal from the first electrocardiogram electrode and the signal from the second electrocardiogram electrode, and the signal from the first electrocardiogram electrode and the third electrocardiogram electrode A differential amplification unit for performing differential amplification with a signal and performing differential amplification between the signal from the second electrocardiographic electrode and the signal from the third electrocardiographic electrode; and the differential amplification unit And a detector that detects a pacemaker pulse from the received signal.

  The pacemaker pulse detection device of the present invention includes a first electrocardiogram electrode that is not a dead electrode, a second electrocardiogram electrode that is not a dead electrode, and an electrode connection unit that is connected to the third electrocardiogram electrode that is a dead electrode. Differential amplification of the signal from the first electrocardiogram electrode and the signal from the second electrocardiogram electrode, and the signal from the first or second electrocardiogram electrode and the third electrocardiogram A configuration having a differential amplifying unit that differentially amplifies the signal from the electrode and a detecting unit that detects a pacemaker pulse from the signal obtained by the differential amplifying unit is adopted.

  The pacemaker pulse detection device of the present invention includes a first electrocardiogram electrode that is not a dead electrode, a second electrocardiogram electrode that is not a dead electrode, and an electrode connection unit that is connected to the third electrocardiogram electrode that is a dead electrode. Differential amplification of the signal from the first electrocardiogram electrode and the signal from the third electrocardiogram electrode, and the signal from the second electrocardiogram electrode and the signal from the third electrocardiogram electrode A configuration having a differential amplifier that performs differential amplification with a signal and a detector that detects a pacemaker pulse from the signal obtained by the differential amplifier is adopted.

  According to the present invention, pacemaker pulse detection accuracy can be improved without increasing the number of electrocardiographic electrodes to be used.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a pacemaker pulse detection device according to an embodiment of the present invention. The maker pulse detection device 100 includes connecting portions 102a, 102b, 102c, pacemaker pulse pass filters 104a, 104b, 104c, pacemaker pulse amplifiers 106a, 106b, 106c, pacemaker pulse detectors 108a, 108b, 108c, and a pacemaker pulse blocking filter 110. Have.

  The connection part 102a is provided on a signal line for transmitting a signal from the electrocardiogram electrode 12a mounted on the body surface near the left leg of the patient 10, and the electrocardiogram electrode 12a and the buffer amplifier 16a are connected via the connection part 102a. , The (+) input terminal of the pacemaker pulse amplifier 106a and the (+) input terminal of the pacemaker pulse amplifier 106b are electrically connected.

  The connection part 102b is provided on a signal line for transmitting a signal from the electrocardiogram electrode 12b mounted on the body surface near the right arm of the patient 10, and the electrocardiogram electrode 12b and the buffer amplifier 16b are connected via the connection part 102b. The input terminal, the (−) input terminal of the pacemaker pulse amplifier 106a, and the (+) input terminal of the pacemaker pulse amplifier 106c are electrically connected.

  The buffer amplifiers 16a and 16b are impedance conversion amplifiers, and signals from the buffer amplifiers 16a and 16b are input to the (+) input terminal and the (−) input terminal of the electrocardiographic amplifier 18, respectively. The electrocardiograph 18 performs differential amplification of the input signal and outputs a signal having an electrocardiogram waveform.

  The connection part 102c is provided on a signal line for transmitting a signal from the electrocardiogram electrode 12c mounted on the body surface near the left arm of the patient 10, and the electrocardiogram electrode 12c and the pacemaker pulse amplifier 106b are connected via the connection part 102c. The (−) input terminal and the (−) input terminal of the pacemaker pulse amplifier 106c and the ground terminal (N) are electrically connected.

  The pacemaker pulse pass filter 104a is provided between the connection portion 102a and the (+) input terminal of the pacemaker pulse amplifier 106a, and between the connection portion 102b and the (−) input terminal of the pacemaker pulse amplifier 106a. Only the frequency components of about 1 to 10 kHz in the signals from the electrodes 12a and 12b are allowed to pass, and these components are input to the (+) input terminal and the (−) input terminal of the pacemaker pulse amplifier 106a, respectively. Note that approximately 1 to 10 kHz is the main frequency band of the pacemaker pulse.

  The pacemaker pulse amplifier 106a performs differential amplification of the signal input from the pacemaker pulse pass filter 104a. The output terminal of the pacemaker pulse amplifier 106a is connected to the pacemaker pulse detector 108a, and the differential output signal output from the pacemaker pulse amplifier 106a as a result of differential amplification is input to the pacemaker pulse detector 108a.

  The pacemaker pulse detector 108a detects a pacemaker pulse from the input differential output signal.

  The pacemaker pulse pass filter 104b is provided between the connection portion 102a and the (+) input terminal of the pacemaker pulse amplifier 106b, and between the connection portion 102c and the (−) input terminal of the pacemaker pulse amplifier 106b. Only the frequency components of about 1 to 10 kHz in the signals from the electrodes 12a and 12c are allowed to pass, and these components are input to the (+) input terminal and the (−) input terminal of the pacemaker pulse amplifier 106b, respectively.

  The pacemaker pulse amplifier 106b performs differential amplification of the signal input from the pacemaker pulse pass filter 104b. The output terminal of pacemaker pulse amplifier 106b is connected to pacemaker pulse detector 108b, and the differential output signal output from pacemaker pulse amplifier 106b as a result of differential amplification is input to pacemaker pulse detector 108b.

  The pacemaker pulse detector 108b detects a pacemaker pulse from the input differential output signal.

  The pacemaker pulse pass filter 104c is provided between the connection portion 102b and the (+) input terminal of the pacemaker pulse amplifier 106c, and between the connection portion 102c and the (−) input terminal of the pacemaker pulse amplifier 106c. Only the frequency components of about 1 to 10 kHz in the signals from the electrodes 12b and 12c are allowed to pass, and these components are input to the (+) input terminal and the (−) input terminal of the pacemaker pulse amplifier 106c, respectively.

  The pacemaker pulse amplifier 106c performs differential amplification of the signal input from the pacemaker pulse pass filter 104c. The output terminal of pacemaker pulse amplifier 106c is connected to pacemaker pulse detector 108c, and the differential output signal output from pacemaker pulse amplifier 106c as a result of differential amplification is input to pacemaker pulse detector 108c.

  The pacemaker pulse detector 108c detects a pacemaker pulse from the input differential output signal.

  In the above configuration, the pacemaker pulse amplifiers 106a to 106c constitute a differential amplification unit, the pacemaker pulse detectors 108a to 108c constitute a detection unit, and the pacemaker pulse pass filters 104a to 104c constitute the first filter unit. The connecting portions 102a to 102d constitute an electrode connecting portion. Of the electrocardiographic electrodes 12a to 12c, the electrocardiographic electrode 12c is a dead electrode connected to the ground terminal (N) and grounded. A pacemaker pulse blocking filter 110 as a second filter unit is provided in the ground unit that connects the connection unit 102c and the ground terminal (N) and grounds the electrocardiogram electrode 12c.

  The pacemaker pulse blocking filter 110 passes a frequency component other than about 1 to 10 kHz in the signal from the electrocardiogram electrode 12c to the ground terminal (N), while blocking a frequency component of about 1 to 10 kHz.

  Here, a case where the pacemaker pulse detection process is performed using the electrocardiogram electrodes 12a to 12c in the electrocardiogram measurement under a specific situation will be described.

  FIG. 2 shows a situation where the electrical relative angle between the stimulation electrode portion of the pacemaker lead 20 implanted in the body of the patient 10 and the pair of electrocardiographic electrodes 12a and 12b is substantially perpendicular. Yes. In FIG. 2, in order to easily understand the situation where the electrical relative angle is substantially a right angle, the pacemaker lead 20 is physically connected to the stimulation electrode portion and the pair of electrocardiographic electrodes 12 a and 12 b. However, since the body tissue is generally non-uniform, the electrical relative angle can be a right angle due to the influence of the body tissue even if the physical relative angle is not a right angle.

  Since the combination of the electrocardiographic electrodes 12a and 12b makes a right angle with the indwelling direction of the pacemaker lead 20, there is no potential difference in the signals from the electrocardiographic electrodes 12a and 12b. Therefore, even if these input signals are differentially amplified by the pacemaker pulse amplifier 106a, it is difficult to accurately detect the pacemaker pulse, and the pacemaker pulse detector 108a does not show a pacemaker pulse waveform. Is output.

  On the other hand, since the combination of the electrocardiographic electrodes 12a and 12c does not form a right angle with the indwelling direction of the pacemaker lead 20, a potential difference is generated in signals from the electrocardiographic electrodes 12a and 12c. Therefore, when these input signals are differentially amplified by the pacemaker pulse amplifier 106b, the pacemaker pulse can be accurately detected, and the pacemaker pulse detector 108b outputs a signal 22b in which the pacemaker pulse waveform appears. The

  Further, since the combination of the electrocardiographic electrodes 12b and 12c does not form a right angle with the indwelling direction of the pacemaker lead 20, a potential difference also occurs in the signals from the electrocardiographic electrodes 12b and 12c. Therefore, when these input signals are differentially amplified by the pacemaker pulse amplifier 106c, the pacemaker pulse can be accurately detected, and the pacemaker pulse detector 108c outputs a signal 22c in which the pacemaker pulse waveform appears. The

  Thus, according to the present embodiment, signals are detected from a plurality of directions with respect to the pacemaker implanted in the body using the three electrocardiographic electrodes 12a to 12c. For this reason, even if the pacemaker used is a bipolar type, an arrangement of electrocardiographic electrodes that does not form a right angle to the pacemaker is always obtained. Therefore, a pacemaker pulse can be accurately detected by a signal input from any combination of electrocardiographic electrodes, and the miss of the pacemaker pulse can be prevented. Further, the detection direction of the pacemaker pulse is not increased by increasing the number of electrocardiographic electrodes used for pacemaker pulse detection in this way, but is increased by actively using the dead electrode for pacemaker pulse detection. Thereby, the usability for the user is not impaired.

  In the present embodiment, pacemaker pulses are detected in all three detection directions formed by using three electrocardiographic electrodes, but pacemaker pulses are detected in two of the three detection directions. May be performed.

  In the present embodiment, the case where three electrocardiographic electrodes are used has been described as an example, but four or more electrocardiographic electrodes may be used.

  In addition, according to the present embodiment, differential amplification is simultaneously performed on signals in the three detection directions to perform pacemaker pulse detection, so that the accuracy of pacemaker pulse detection can be improved more reliably. Note that detection in a plurality of detection directions is not necessarily performed at the same time. One of the detection directions is selected in advance and detection is performed in the detection direction, or detection directions are set at fixed or arbitrary time intervals. Detection may be performed while switching.

  In addition, according to the present embodiment, the filter that blocks only the passage of the main frequency component of the pacemaker pulse is provided in the grounding portion that grounds the dead electrode. Normally, the dead electrode has a very low input impedance compared to other electrocardiographic electrodes because it is grounded, but this filter can reduce such a difference in input impedance. Therefore, a pacemaker pulse can be detected with sufficient sensitivity even if differential amplification is performed on a signal from an electrocardiographic electrode that is not a dead electrode and a signal from an electrocardiographic electrode that is a dead electrode.

  The embodiment of the present invention has been described above. The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. That is, the description of the configuration and operation of the above apparatus is an example, and it is obvious that various modifications and additions to these examples are possible within the scope of the present invention.

  The pacemaker pulse detection device of the present invention is useful for detecting a pacemaker pulse at the time of electrocardiogram measurement in various measuring devices (biological information monitor, electrocardiogram telemeter, electrocardiograph, etc.) that can measure the electrocardiogram.

The block diagram which shows the structure of the pacemaker pulse detection apparatus which concerns on one embodiment of this invention The figure for demonstrating the pacemaker pulse waveform output in the pacemaker pulse detection apparatus which concerns on one embodiment of this invention Diagram for explaining the relationship between the pacemaker lead placement direction and the output pacemaker pulse waveform

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Pacemaker pulse detection apparatus 102a, 102b, 102c Connection part 104a, 104b, 104c Pacemaker pulse passage filter 106a, 106b, 106c Pacemaker pulse amplifier 108a, 108b, 108c Pacemaker pulse detector 110 Pacemaker pulse prevention filter

Claims (5)

An electrode connection connected to a first electrocardiogram electrode that is not a dead electrode, a second electrocardiogram electrode that is not a dead electrode, and a third electrocardiogram electrode that is a dead electrode;
Differential amplification of the signal from the first electrocardiogram electrode and the signal from the second electrocardiogram electrode is performed, and the signal from the first electrocardiogram electrode and the signal from the third electrocardiogram electrode A differential amplification unit for performing differential amplification of the signal from the second electrocardiographic electrode and the signal from the third electrocardiographic electrode;
A detection unit for detecting a pacemaker pulse from a signal obtained by the differential amplification unit;
A pacemaker pulse detection device having An electrode connection connected to a first electrocardiogram electrode that is not a dead electrode, a second electrocardiogram electrode that is not a dead electrode, and a third electrocardiogram electrode that is a dead electrode;
Differentially amplifying a signal from the first electrocardiogram electrode and a signal from the second electrocardiogram electrode, and a signal from the first or second electrocardiogram electrode and the third electrocardiogram electrode A differential amplifier for performing differential amplification with a signal from
A detection unit for detecting a pacemaker pulse from a signal obtained by the differential amplification unit;
A pacemaker pulse detection device having An electrode connection connected to a first electrocardiogram electrode that is not a dead electrode, a second electrocardiogram electrode that is not a dead electrode, and a third electrocardiogram electrode that is a dead electrode;
Differential amplification of the signal from the first electrocardiogram electrode and the signal from the third electrocardiogram electrode is performed, and the signal from the second electrocardiogram electrode and the signal from the third electrocardiogram electrode are performed. A differential amplifier for performing differential amplification with
A detection unit for detecting a pacemaker pulse from a signal obtained by the differential amplification unit;
A pacemaker pulse detection device having The differential amplification unit includes differential amplification of a signal from the first electrocardiogram electrode and a signal from the second electrocardiogram electrode, and a signal from the first electrocardiogram electrode and the third Performing differential amplification with the signal from the electrocardiogram electrode and differential amplification with the signal from the second electrocardiogram electrode and the signal from the third electrocardiogram electrode simultaneously;
The pacemaker pulse detection device according to claim 1. A signal input unit connected to the electrode connection unit and inputting a signal from the third electrocardiographic electrode to the differential amplification unit;
A first filter unit provided in the signal input unit and passing a frequency band of a pacemaker pulse in a signal from the third electrocardiogram electrode;
A grounding part connected to the electrode connecting part and grounding the third electrocardiographic electrode;
A second filter unit provided in the grounding unit and blocking a frequency band of a pacemaker pulse in a signal from the third electrocardiographic electrode;
The pacemaker pulse detector according to any one of claims 1 to 4, further comprising:

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