JPH1066735A - Cardiac irregular pulse suppressing electrostimulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely control irregular pulses by generating the stimulation having the polarity opposite to that of the electric stimulation extending the refractory period, applying this stimulation after the stimulation extending the refractory period, and keeping the sum of the charge quantity of the stimulation neutral. SOLUTION: This stimulation output circuit is constituted of a transistor Tr1, a resistor R, and a capacitor C, a transistor Tr2 is additionally connected in parallel with the resistor R of this circuit, and the circuit is controlled by a control signal 9 to generate a reverse-polarity pulse. In this circuit, the current from an electrode +V normally flows through the resistor R, the capacitor C, and the cardiac muscle connected to an output terminal. The capacitor C is gradually charged. When the transistor Tr1 conducts, a stimulative pulse is generated by the discharge of the capacitor C. When the transistor Tr2 conducts, the capacitor C is quickly charged, and a reverse-polarity pulse is generated. The cardiac muscle potential is made neutral, and the occurrence of very dangerous fibrillation is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cardiac arrhythmia suppressing electrical stimulation device for safely controlling arrhythmias.

[0002]

2. Description of the Related Art A conventional arrhythmia suppressing stimulator applies a current, which is several tens times larger than a stimulation current used for normal cardiac pacing, to the heart to suppress tachycardia. Damage to the battery and the consumption of the battery are severe, which has been a problem for long-term use.

[0003] A device intended to prolong the refractory period after myocardial excitation by applying a stimulation pulse to reduce the chance of arrhythmia has been conceived. And has not yet been put to practical use. That is, the stimulation pulse as shown in FIG. 1 was applied to the heart.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a safe arrhythmia controlling electrical stimulator which does not induce fibrillation even when a stimulus for prolonging the refractory period of the heart is performed.

[0005] When such an electrical stimulator for controlling arrhythmia is completed, it will be widely used by those who are in need of arrhythmia and will bring the gospel. In addition, new markets will be created and contribute to the industry.

[0006]

The gist of the present invention will be described with reference to the accompanying drawings.

[0007] An apparatus for providing electrical stimulation for prolonging the refractory period of the heart using an electric pulse, wherein the apparatus is configured to generate a stimulus having a polarity opposite to that of the electrical stimulus for prolonging the refractory period. The present invention relates to an electrical stimulator for cardiac arrhythmia suppression, which is configured to be applied after a stimulus for extending a refractory period so that the sum of charge amounts of the stimulus can be kept neutral.

Further, there is provided an output circuit of a cardiac electric stimulation circuit for realizing the cardiac arrhythmia suppressing electric stimulation method according to claim 1, wherein one end of a power supply is connected to a transistor Tr via a resistor R.
1 and the emitter of the transistor Tr1 is connected to the other polarity of the power supply.
Connected to the output terminal, the other terminal of the output is connected to the emitter of the transistor Tr1, another transistor Tr2 is connected in parallel with the resistor R, and each transistor Tr1,
2. The electrical stimulator for suppressing cardiac arrhythmia according to claim 1, wherein a stimulus output circuit for applying a control signal is provided at the base of Tr2.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention (how to implement the invention) will be briefly described with reference to the drawings, showing the operational effects thereof.

In the method of the present invention, I) after detecting the R-wave as shown in FIG. 2, a discharge pulse of the opposite polarity is applied to the myocardium following the conventional arrhythmia suppressing stimulation pulse.

II) As shown in FIG. 3 (b), a pulse pp for stimulating the heart is applied, and then a discharge pulse of the opposite polarity is applied to the myocardium following the conventional stimulating pulse for arrhythmia suppression.

III) As an application example, as shown in FIG. 3A, in addition to the conventional stimulation pulse, one or a plurality of stimulation pulses are applied, and then a reverse polarity discharge pulse is applied to the myocardium. Good.

IV) Further, two or more discharge pulses of opposite polarities may be applied.

In practice, one end of a conductive catheter is connected to the output terminal of the stimulator and the other end is contacted or fixed to the myocardium (not shown) in the same manner as in a conventional cardiac pacemaker to stimulate the myocardium. One end of the stimulator and the conducting catheter may be external to the body or may be implanted within the body.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A circuit according to a preferred embodiment of the present invention for easily generating a reverse polarity pulse and generating a neutralizing action without any excess or shortage will be described. The technique for generating the timing for generating the pulse will not be described here because the analog or digital technique which has been conventionally implemented can be applied as it is.

First, a circuit diagram is shown.

1) FIG. 5 shows a circuit I of the present invention. Conventionally, the most frequently used stimulus output circuit is composed of a transistor Tr1, a resistor R and a capacitor C as shown in FIG. 4, and a transistor Tr2 is connected in parallel with the resistor R of this circuit.
Are additionally connected, and a reverse polarity pulse is generated by controlling opening and closing by a control signal.

2) Another specific example is shown in FIG. 6 as a circuit II of the present invention. A transistor Tr2 is added in parallel with the resistor R of the conventional circuit, and a resistor R2 is added to generate a reverse polarity pulse. The amount of current of the reverse polarity pulse can be adjusted by the resistor R2.

3) FIG. 7 shows a circuit according to another embodiment of the present invention.
Shown in III. A transistor in which a transistor Tr2 and a resistor R3 are connected in series is added in parallel with the resistor R of the conventional circuit to generate a reverse polarity pulse. The amount of current of the reverse polarity pulse can be adjusted by the resistor R3.

If the value of the resistor R can be made very large in the above 1), 2) and 3), the resistor R can be removed from the circuit.

Further, as a completely different circuit, a circuit for generating a reverse polarity pulse is provided, and this circuit is connected to a circuit for generating a stimulus pulse, thereby achieving the effect of neutralizing the accumulated charge of the method of the present invention. Needless to say, this is possible.

Next, the operation will be described.

The prior art is shown in FIG. When the R wave of the electrocardiogram is detected, only a refractory period extension stimulation pulse is applied after a certain period. When two or three stimulation pulses for extending the refractory period are applied within a short period of time, electric charges are accumulated in the myocardium. When this is repeated, the myocardial potential eventually increases, and the state shifts to a very dangerous fibrillation state. For this reason, this technique has been in the experimental stage until now.

According to the present invention, the transistor Tr2 is added as shown in the above configuration circuit to generate a pulse of the opposite polarity as shown in FIG. 2, so that the electric charge of the myocardium is neutralized and the myocardial potential is neutral. Therefore, there is a great advantage that very dangerous fibrillation does not occur.

The necessity of a technique for applying a stimulation pulse and a reverse polarity pulse at a short time after the myocardial stimulation pulse PP as shown in FIG. 3B is as follows. The myocardial stimulation pulse PP is as large as several volts, whereas the myocardial excitation voltage is much as small as a few millivolts. In some cases, the judgment cannot be made. To avoid this, the operation is ensured by applying the stimulus pulse and the reverse polarity pulse regardless of whether or not the excitement has occurred.

If the pulse width of the reverse polarity pulse is adjusted,
The electric charge stored in the myocardium can be sufficiently discharged.

Although the ventricular muscle has been described above, it goes without saying that the same action is performed on the atrial muscle.

Here, the operation of the circuit of the present invention for generating pulses of opposite polarity will be described.

In FIG. 5, the current from the power supply + V flows through the resistor R, the capacitor C and the myocardium (not shown) connected to the output terminal. At this time, the capacitor C is gradually charged (at this point, the myocardial potential hardly changes, because the myocardial potential is gradually charged and is canceled by the self-discharge effect inside the myocardium). By control signal
When Tr1 conducts, the capacitor C discharges and a stimulus pulse or is generated (at this time, the myocardial potential increases). Next, when Tr2 is turned on by the control signal, the capacitor C is rapidly charged, and a reverse polarity pulse is generated at this time (the myocardial potential becomes neutral). Since the resistor R2 in FIG. 6 or the resistor R3 in FIG. 7 is inserted in the current path, the amount of current of the reverse polarity pulse can be controlled.

[0030]

Since the present invention is constructed as described above, according to the first aspect of the present invention, there is a high possibility that electric charge is accumulated in the myocardium to induce fibrillation in the prior art. Fibrillation may occur 1-3 minutes after the start of stimulation. At this time, when the potential of the myocardium is being measured, the potential gradually increases, and when the potential exceeds a certain potential, the fibrillation shifts to dangerous. It is a well-known fact that electricity is very dangerous to the heart muscle. According to the technique of the present invention, the electric charge accumulated in the myocardium is neutralized by the pulse of the opposite polarity, no electric charge accumulation occurs, the myocardial potential remains neutral, and fibrillation is not induced. At this time,
Even if the potential of the myocardium is measured, the potential does not change and remains neutral. For this reason, a cardiac arrhythmia suppressing electrical stimulator having excellent features that can safely extend the refractory period of the myocardium and safely control arrhythmias is provided.

According to the second aspect of the present invention, the circuit of the present invention is extremely practical because it can realize a reverse-polarity pulse by simply adding components to the conventional circuit. The myocardial stimulation pulse is as large as several volts, whereas the myocardial excitation voltage is much as small as several millivolts. May not be possible. In order to avoid this, regardless of whether or not the excitement has occurred, application of the stimulus pulse and the reverse-polarity pulse has excellent features such as reliable operation.

In addition, the effects from the aspect of patient treatment are as follows:
Treatment of arrhythmias that cannot be controlled even with drugs has been difficult, and there is always the risk of inducing fibrillation and dying.
By using this device prophylactically for such dangerous patients, the risk of inducing fibrillation can be greatly reduced, and the gospel will be great for patients.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing how to apply a pulse according to a conventional technique.

FIG. 2 is an explanatory diagram showing how to apply a pulse according to the present embodiment.

FIG. 3 is an explanatory diagram showing an application example of the present embodiment.

FIG. 4 is an explanatory diagram showing a conventional circuit.

FIG. 5 is an explanatory diagram of a configuration of a circuit according to the present embodiment.

FIG. 6 is a configuration explanatory diagram showing an application example (1) of the circuit of the present embodiment.

FIG. 7 is a configuration explanatory diagram showing an application example (part 2) of the circuit of the present embodiment.

[Description of Signs]: Stimulation pulse for refractory period extension: Stimulation pulse train for refractory period extension: Reverse polarity pulse: Control signal: Control signal PP: Cardiac pacing pulse C: Capacitor R: Resistance R2: Resistance R3: Resistance Tr1: Transistor Tr2 : Transistor + V: Power supply

Claims (2)

[Claims] An apparatus for providing electrical stimulation for extending a refractory period of a heart using an electrical pulse, wherein the stimulation is configured to generate a stimulus having a polarity opposite to that of the electrical stimulation for extending a refractory period. Is applied after the stimulus for extending the refractory period, so that the sum of the charges of the stimulus can be kept neutral. 2. An output circuit of a cardiac electrical stimulation circuit for realizing the cardiac arrhythmia suppressing electrical stimulation method according to claim 1, wherein one end of a power supply is connected to a collector of a transistor Tr1 via a resistor R. The emitter of Tr1 is connected to the other polarity of the power supply, the collector is connected to the output terminal via the capacitor C, the other terminal of the output is connected to the emitter of the transistor Tr1, and another transistor Tr2 is connected to the resistor R. Connected in parallel, each transistor Tr1, Tr
2. The electrical stimulator for cardiac arrhythmia suppression according to claim 1, wherein a stimulus output circuit for applying a control signal is provided at a base of the stimulator.