JP5566228B2 - Nerve stimulator - Google Patents

Description

  The present invention relates to a nerve stimulation apparatus.

  2. Description of the Related Art Conventionally, an implantable heart treatment device that performs heart treatment by electrically stimulating the vagus nerve for the purpose of preventing sudden death caused by heart disease is known (see, for example, Patent Document 1). . This heart treatment device detects an intracardiac electrogram using an intracardiac lead, acquires a heart rate from the intracardiac electrogram, adjusts the nerve stimulation intensity according to the acquired heart rate, and controls the heart rate To do.

Japanese Patent No. 4381044

  However, according to the heart treatment device disclosed in Patent Document 1 described above, since the nerve stimulation pulse propagates into the heart cavity through the living body, the nerve stimulation pulse propagated in the living body is erroneously detected as a heartbeat. There is an inconvenience.

  The present invention has been made in view of the above-described circumstances, and can prevent a nerve stimulation pulse that has propagated in a living body from being erroneously detected as a heartbeat, and can perform nerve stimulation with high accuracy. An object is to provide an apparatus.

In order to achieve the above object, the present invention employs the following means.
The present invention includes neural stimulation means for generating stimulation pulses for stimulating the vagus nerve, electrocardiogram generation means for detecting an electrical signal from the heart and generating an electrocardiogram waveform, and an electrocardiogram waveform generated by the electrocardiogram generation means Storage means for storing the generated noise waveform, correction electrocardiogram generation means for correcting the electrocardiogram waveform generated by the electrocardiogram generation means using the noise waveform stored in the storage means, and generating a corrected electrocardiogram waveform ; Noise waveform extraction means for extracting a noise waveform by the nerve stimulation means from an electrocardiogram waveform generated by the electrocardiogram generation means , and the nerve stimulation means is based on the corrected electrocardiogram waveform generated by the correction electrocardiogram generation means the stimulation pulses generated, the noise waveform extracting noise waveform extracted by means stored in said storage means, said noise Shape extracting means at the timing of stimulation with the nerve stimulation unit, by averaging the generated electrocardiogram waveform by the electrocardiogram generating means, for providing a neural stimulator for extracting noise waveform by the nerve stimulation device.

  According to the present invention, the electrocardiogram generation means detects an electrical signal from the heart to generate an electrocardiogram waveform, and the noise waveform included in the generated electrocardiogram waveform is stored in the storage means. Then, the corrected electrocardiogram generation unit corrects the electrocardiogram waveform generated by the electrocardiogram generation unit using the noise waveform stored in the storage unit, and generates a corrected electrocardiogram waveform. Based on the corrected electrocardiogram waveform thus generated, a stimulation pulse for stimulating the vagus nerve is generated by the nerve stimulation means. By doing in this way, it can prevent misdetecting the nerve stimulation pulse which propagated in the living body as a heartbeat, and can perform highly accurate nerve stimulation.

Further, with the noise waveform extracting means for extracting a noise waveform by the nerve stimulation means from the electrocardiogram wave generated by the electrocardiogram generating means, noise waveform extracted by said noise waveform extracting means, Ru stored in said storage means . That is, the noise waveform extraction means can extract the noise waveform (that is, the nerve stimulation pulse propagated in the living body) by the nerve stimulation means from the electrocardiogram waveform generated by the electrocardiogram generation means and store it in the storage means. As a result, for example, even when the intensity of the stimulation pulse that stimulates the vagus nerve is changed, the noise waveform corresponding to the intensity of the stimulation pulse can be extracted in real time, and the noise detection accuracy can be improved. Appropriate nerve stimulation can be performed.

Furthermore, the noise waveform extracting means, the timing of stimulation with the nerve stimulation unit, by averaging the generated electrocardiogram waveform by the electrocardiogram generating means, since the extracted noise waveform by the nerve stimulation device, neural stimulation By averaging the electrocardiogram waveforms generated by the electrocardiogram generation means at the timing of stimulation by the means, the noise waveform by the nerve stimulation means can be easily extracted. Thereby, the noise detection accuracy can be improved and more appropriate nerve stimulation can be performed.

According to another aspect of the present invention, a nerve stimulation unit that generates a stimulation pulse for stimulating the vagus nerve, an electrocardiogram generation unit that detects an electrical signal from the heart and generates an electrocardiogram waveform, and the electrocardiogram generation unit Storage means for storing a noise waveform included in the electrocardiogram waveform, and a corrected electrocardiogram for correcting the electrocardiogram waveform generated by the electrocardiogram generation means by using the noise waveform stored in the storage means to generate a corrected electrocardiogram waveform Generating means, wherein the nerve stimulation means generates a stimulation pulse based on the corrected electrocardiogram waveform generated by the correction electrocardiogram generation means, and the correction electrocardiogram generation means matches the timing of stimulation by the nerve stimulation means. Then, a noise inversion waveform obtained by inverting the noise waveform stored in the storage unit is added to the electrocardiogram waveform generated by the electrocardiogram generation unit. And to provide a neural stimulator for generating a correction electrocardiogram waveform.
Corrected by adding a noise inversion waveform obtained by inverting the noise waveform stored in the storage means to the electrocardiogram waveform generated by the electrocardiogram generation means by the correction electrocardiogram generation means in accordance with the timing of the stimulation by the nerve stimulation means. An electrocardiogram waveform can be easily generated. Then, based on the corrected electrocardiogram waveform generated in this way, it is possible to perform highly accurate nerve stimulation by generating a stimulation pulse that stimulates the vagus nerve.

Still another aspect of the present invention includes a nerve stimulation unit that generates a stimulation pulse for stimulating the vagus nerve, an electrocardiogram generation unit that detects an electrical signal from the heart and generates an electrocardiogram waveform, and the electrocardiogram generation unit Storage means for storing a noise waveform included in the electrocardiogram waveform, and correction for generating a corrected electrocardiogram waveform by correcting the electrocardiogram waveform generated by the electrocardiogram generation means using the noise waveform stored in the storage means An electrocardiogram generation unit, wherein the nerve stimulation unit generates a stimulation pulse based on the corrected electrocardiogram waveform generated by the correction electrocardiogram generation unit, and the correction electrocardiogram generation unit detects the timing of the stimulation by the nerve stimulation unit. In addition, the noise waveform stored in the storage means is subtracted from the electrocardiogram waveform generated by the electrocardiogram generation means, and a corrected electrocardiogram wave is obtained. Provide neural stimulator for generating.
The corrected electrocardiogram waveform is easily generated by subtracting the noise waveform stored in the storage means from the electrocardiogram waveform generated by the electrocardiogram generator in accordance with the timing of the stimulation by the nerve stimulation means. be able to. Then, based on the corrected electrocardiogram waveform generated in this way, it is possible to perform highly accurate nerve stimulation by generating a stimulation pulse that stimulates the vagus nerve.

  According to the present invention, it is possible to prevent erroneous detection of a nerve stimulation pulse transmitted through a living body as a heartbeat, and to perform highly accurate nerve stimulation.

1 is an overall configuration diagram of a nerve stimulation device according to each embodiment of the present invention. It is a functional block diagram of the nerve stimulating device concerning a 1st embodiment. It is a figure which shows the electrocardiogram waveform detected by the heartbeat detection part of FIG. It is a flowchart which shows the process performed by the nerve stimulation apparatus of FIG. It is a functional block diagram of the nerve stimulation apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the process (process until it memorize | stores a correction | amendment pulse) performed by the nerve stimulation apparatus of FIG. It is a flowchart which shows the process (The process until it produces | generates a correction | amendment electrocardiogram using the memorize | stored correction pulse) performed by the nerve stimulation apparatus of FIG.

[First Embodiment]
A nerve stimulation apparatus 1 according to a first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the nerve stimulation device 1 according to the present embodiment includes a device main body 2 embedded in the body, a first electrode unit 4 attached to the vagus nerve A, a device main body 2, and a first A nerve stimulation lead 3 that connects the electrode unit 4, a second electrode unit 5 attached to the heart B, and a heartbeat detection lead 6 that connects the apparatus main body 2 and the second electrode unit 5 are provided. .

The first electrode portion 4 has an anode electrode and a cathode electrode that are electrically insulated from each other (not shown). Each electrode is formed in a cylindrical shape, for example, and is attached so as to cover the side surface of the vagus nerve A in the circumferential direction.
The second electrode unit 5 is attached to the right ventricle of the heart B, for example, and detects an electrocardiographic signal from the heart B.

FIG. 2 is a functional block diagram showing the functions of the apparatus main body 2 in an expanded manner.
As shown in FIG. 2, the apparatus body 2 includes a heartbeat detection unit (electrocardiogram generation unit) 11, a signal combination unit (correction electrocardiogram generation unit) 12, a noise acquisition unit (noise waveform extraction unit) 13, and a correction pulse. A calculation unit 14, a correction pulse storage unit (storage unit) 15, a timing generation unit 16, and a nerve stimulation output unit (nerve stimulation unit) 17 are provided.

  The heartbeat detection unit 11 generates an electrocardiogram waveform from an electrocardiogram signal from the heart B detected by the second electrode unit 5, and detects a heartbeat. Specifically, the heartbeat detection unit 11 is configured to detect a period of an R wave that becomes a peak in an electrocardiogram and indicates an excited state of the ventricle, for example. The electrocardiogram waveform generated in this way is output to the signal coupling unit 12.

  The noise acquisition unit 13 acquires a noise waveform from the electrocardiogram waveform generated by the heartbeat detection unit 11. As shown in FIG. 1, this noise is noise that has circulated in the living body, and a nerve stimulation pulse given to the vagus nerve A from the nerve stimulation output unit 17 via the nerve stimulation lead 3 passes through the living body. It occurs when it passes through and propagates to the heart B. As shown in FIG. 3, a plurality of noise waveforms appear at the timing of nerve stimulation by the nerve stimulation output unit 17.

  The noise acquisition unit 13 acquires a noise waveform that appears in this way by calculation. Specifically, the noise acquisition unit 13 acquires the noise waveform by the nerve stimulation output unit 17 by averaging the electrocardiogram waveform generated by the heartbeat detection unit 11 at the timing of stimulation by the nerve stimulation output unit 17. It is like that.

  As illustrated in FIG. 3, the correction pulse calculation unit 14 inverts the noise waveform acquired by the noise acquisition unit 13 and outputs the inverted waveform to the correction pulse storage unit 15 as a nerve stimulation noise reverse phase signal.

The correction pulse storage unit 15 stores the neural stimulation noise reverse phase signal output from the correction pulse calculation unit 14 in time series and stores it as a correction pulse.
The timing generation unit 16 outputs a nerve stimulation timing signal to the correction pulse storage unit 15 and the nerve stimulation output unit 17.

  The signal combination unit 12 corrects the electrocardiogram waveform generated by the heartbeat detection unit 11 using the correction pulse stored in the correction pulse storage unit 15 to generate a correction electrocardiogram waveform. Specifically, as shown in FIG. 3, the signal combining unit 12 generates a noise inversion waveform obtained by inverting the noise waveform stored in the correction pulse storage unit 15 in accordance with the timing of stimulation by the nerve stimulation output unit 17. The corrected electrocardiogram waveform is generated by adding to the electrocardiogram waveform generated by the heartbeat detection unit 11.

  The nerve stimulation output unit 17 generates a stimulation pulse for stimulating the vagus nerve A based on the timing signal from the timing generation unit 16 and the corrected electrocardiogram waveform generated by the signal coupling unit 12, and outputs the stimulation pulse to the nerve stimulation lead. 3 to the respective electrodes of the first electrode unit 4. Thereby, in the position arrange | positioned between each electrode of the 1st electrode part 4, the vagus nerve A is stimulated by the stimulation pulse and excited, and the heart rate is lowered.

  The nerve stimulation output unit 17 can increase or decrease the stimulation applied to the vagus nerve A by increasing or decreasing the energy of the stimulation pulse by increasing or decreasing the pulse width of the generated stimulation pulse. .

The operation of the nerve stimulation apparatus 1 having the above configuration will be described below using the flowchart shown in FIG.
The nerve stimulation apparatus 1 according to the present embodiment is embedded in the body of a patient performing heart treatment, the first electrode unit 4 is disposed on the vagus nerve A such as the cervix, and the second electrode unit 5 is For example, it is attached to the right ventricle of heart B.

  In this state, the operation of the nerve stimulation apparatus 1 is started, and a stimulation pulse is output from the nerve stimulation output unit 17 to each electrode of the first electrode unit 4 via the nerve stimulation lead 3 to intermittently cause the vagus nerve A. Is stimulated (step S1).

Next, an intracardiac electrocardiogram is acquired from the electrocardiogram signal from the heart B detected by the second electrode unit 5 by the heartbeat detection unit 11 (step S2).
Next, the noise acquisition unit 13 acquires a noise waveform of neural stimulation from the electrocardiogram waveform generated by the heartbeat detection unit 11 (step S3). Specifically, the noise waveform by the nerve stimulation output unit 17 is acquired by averaging the electrocardiogram waveform generated by the heartbeat detection unit 11 at the timing of stimulation by the nerve stimulation output unit 17.

  Next, the correction pulse calculation unit 14 calculates the correction pulse by inverting the noise waveform acquired by the noise acquisition unit 13 (step S4). The correction pulse calculated in this way is stored in the correction pulse storage unit 15.

  Next, a correction electrocardiogram waveform is generated from the correction pulse stored in the correction pulse storage unit 15 and the electrocardiogram waveform generated by the heartbeat detection unit 11 by the signal combining unit 12. Specifically, the heartbeat detection unit 11 generates a noise inversion waveform obtained by inverting the noise waveform stored in the correction pulse storage unit 15 in accordance with the timing of the stimulation by the nerve stimulation output unit 17 by the signal combination unit 12. The added ECG waveform is added (step S5). By doing in this way, the correction | amendment electrocardiogram waveform from which the noise by the nerve stimulation output part 17 was reduced is produced | generated from the electrocardiogram waveform (step S6).

  Then, based on the corrected electrocardiogram waveform generated as described above and the timing signal from the timing generator 16, a stimulation pulse is generated by the nerve stimulation output unit 17, and the vagus nerve A is stimulated.

  As described above, according to the nerve stimulation apparatus 1 according to the present embodiment, the heartbeat detection unit 11 detects an electrical signal from the heart B to generate an electrocardiogram waveform, and a noise waveform included in the generated electrocardiogram waveform. Is stored in the correction pulse storage unit 15. Then, the electrocardiogram waveform generated by the heartbeat detection unit 11 is corrected by the signal combining unit 12 using the noise waveform stored in the correction pulse storage unit 15, and a corrected electrocardiogram waveform is generated. Based on the corrected electrocardiogram waveform thus generated, the nerve stimulation output unit 17 generates a stimulation pulse for stimulating the vagus nerve A. By doing in this way, it can prevent misdetecting the nerve stimulation pulse which propagated in the living body as a heartbeat, and can perform highly accurate nerve stimulation.

  Further, the noise acquisition unit 13 acquires the noise waveform (that is, the nerve stimulation pulse propagated in the living body) by the nerve stimulation output unit 17 from the electrocardiogram waveform generated by the heartbeat detection unit 11, for example, the vagus nerve A Even when the intensity of the stimulation pulse that stimulates the sound is changed, the noise waveform corresponding to the intensity of the stimulation pulse can be acquired in real time, and the noise detection accuracy can be improved to perform more appropriate nerve stimulation Can do.

  Further, by averaging the electrocardiogram waveform generated by the heartbeat detection unit 11 at the timing of stimulation by the nerve stimulation output unit 17, the noise waveform by the nerve stimulation output unit 17 can be easily extracted. Thereby, the noise detection accuracy can be improved and more appropriate nerve stimulation can be performed.

  In addition, an electrocardiogram generated by the heartbeat detection unit 11 is a noise inversion waveform obtained by inverting the noise waveform stored in the correction pulse storage unit 15 by the signal combining unit 12 in accordance with the timing of the stimulation by the nerve stimulation output unit 17. By adding to the waveform, a corrected electrocardiogram waveform can be easily generated. Then, by generating a stimulation pulse that stimulates the vagus nerve A based on the corrected electrocardiogram waveform generated in this way, highly accurate nerve stimulation can be performed.

[Second Embodiment]
Next, a nerve stimulation device 10 according to a second embodiment of the present invention will be described mainly with reference to FIGS.
The nerve stimulation apparatus 10 according to this embodiment is different from the above-described embodiment in that a noise waveform by the nerve stimulation output unit 17 is acquired in advance and the acquired noise waveform is stored in the correction pulse storage unit 15. It is. Hereinafter, with respect to the nerve stimulation apparatus 10 of the present embodiment, description of points that are common to the first embodiment will be omitted, and different points will be mainly described.

  As shown in FIG. 5, the nerve stimulation apparatus 10 according to the present embodiment has functions of the noise acquisition unit 13 and the correction pulse calculation unit 14 illustrated in FIG. 2 provided to an external device (not illustrated). 1 includes a heart rate detection unit (electrocardiogram generation means) 11, a signal combination unit (correction electrocardiogram generation unit) 12, a correction pulse storage unit (storage unit) 15, a timing generation unit 16, and a nerve stimulation output unit (neural stimulation). Means) It is sufficient that the function 17 is provided.

The operation of the nerve stimulation apparatus 10 according to the present embodiment will be described below using the flowcharts shown in FIGS. 6 and 7.
FIG. 6 is a flowchart showing a process until a correction pulse is acquired and stored, and FIG. 7 is a flowchart showing a process until a corrected intracardiac electrocardiogram is acquired using the stored correction pulse.

Since the processing from outputting the nerve stimulation pulse in FIG. 6 (step S1) until acquiring the correction pulse (step S4) is the same as in the above-described embodiment, the description thereof is omitted here.
In step S4, the correction pulse calculation unit 14 inverts the noise waveform acquired by the noise acquisition unit 13, so that the calculated correction pulse is stored in the correction pulse storage unit 15 (step S7).

  In order to obtain a corrected intracardiac electrocardiogram using the correction pulses stored in this way, as shown in FIG. 7, after outputting a nerve stimulation pulse (step S1) and acquiring the intracardiac electrocardiogram (step S2), a process for calling the correction pulse stored in the correction pulse storage unit 15 is performed (step S8).

  Next, a correction electrocardiogram waveform is generated from the correction pulse called from the correction pulse storage unit 15 and the electrocardiogram waveform generated by the heartbeat detection unit 11 by the signal combining unit 12. Specifically, the heartbeat detection unit 11 generates a noise inversion waveform obtained by inverting the noise waveform stored in the correction pulse storage unit 15 in accordance with the timing of the stimulation by the nerve stimulation output unit 17 by the signal combination unit 12. The added ECG waveform is added (step S5). By doing in this way, the correction | amendment electrocardiogram waveform from which the noise by the nerve stimulation output part 17 was reduced is produced | generated from the electrocardiogram waveform (step S6).

  Then, based on the corrected electrocardiogram waveform generated as described above and the timing signal from the timing generator 16, a stimulation pulse is generated by the nerve stimulation output unit 17, and the vagus nerve A is stimulated.

As described above, according to the nerve stimulation apparatus 10 according to the present embodiment, the nerve stimulation output is performed based on the corrected electrocardiogram waveform in which noise from the nerve stimulation output unit 17 is reduced from the electrocardiogram waveform, as in the above-described embodiment. The unit 17 generates a stimulation pulse that stimulates the vagus nerve A. By doing in this way, it can prevent misdetecting the nerve stimulation pulse which propagated in the living body as a heartbeat, and can perform highly accurate nerve stimulation.
In this case, the noise waveform is stored in the correction pulse storage unit 15 in advance, and the corrected electrocardiogram waveform is generated using the stored noise waveform, thereby facilitating the processing when generating the corrected electrocardiogram waveform. Can be.

As mentioned above, although each embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention. .
For example, by subtracting the noise waveform stored in the correction pulse storage unit 15 from the electrocardiogram waveform generated by the heartbeat detection unit 11 by the signal combining unit 12 in accordance with the timing of stimulation by the nerve stimulation output unit 17, A corrected electrocardiogram waveform may be generated. By generating a stimulation pulse for stimulating the vagus nerve A based on the corrected electrocardiogram waveform generated in this manner, highly accurate nerve stimulation can be performed.

  In addition, the magnitude of nerve stimulation noise varies depending on the intensity of nerve stimulation (voltage, current, pulse width), so when changing the intensity of nerve stimulation, the magnitude of the correction pulse is adjusted according to the intensity of nerve stimulation. It is good to do.

  In the second embodiment, the noise of nerve stimulation may be measured once immediately after being embedded in the body. However, since the detected nerve stimulation noise may change depending on the positional deviation of the lead wire or the living body, it is preferable to acquire the nerve stimulation noise periodically, for example, once a month.

  Further, since the heart rate normally decreases due to stimulation of the vagus nerve A, when the heart rate increases due to nerve stimulation, it may be determined that the nerve stimulation noise is erroneously detected, and the correction pulse may be acquired again.

DESCRIPTION OF SYMBOLS 1,10 Nerve stimulation apparatus 2 Apparatus main body 3 Nerve stimulation lead 4 1st electrode part 5 2nd electrode part 6 Heart rate detection lead 11 Heart rate detection part (electrocardiogram generation hand means)
12 Signal coupling part (corrected electrocardiogram generation means)
13 Noise acquisition unit (noise waveform extraction means)
14 Correction Pulse Calculation Unit 15 Correction Pulse Storage Unit (Storage Unit)
16 Timing generator 17 Neural stimulation output unit (neural stimulation means)
A vagus nerve B heart

Claims (3)

A nerve stimulation means for generating a stimulation pulse for stimulating the vagus nerve,
An electrocardiogram generating means for detecting an electrical signal from the heart and generating an electrocardiogram waveform;
Storage means for storing a noise waveform included in the electrocardiogram waveform generated by the electrocardiogram generation means;
Corrected electrocardiogram generation means for correcting the electrocardiogram waveform generated by the electrocardiogram generation means using a noise waveform stored in the storage means to generate a corrected electrocardiogram waveform ;
A noise waveform extraction means for extracting a noise waveform by the nerve stimulation means from an electrocardiogram waveform generated by the electrocardiogram generation means ,
The nerve stimulation means generates a stimulation pulse based on the corrected electrocardiogram waveform generated by the correction electrocardiogram generation means ;
The noise waveform extracted by the noise waveform extraction unit is stored in the storage unit,
The nerve stimulation apparatus which extracts the noise waveform by the said nerve stimulation means by the said noise waveform extraction means averaging the electrocardiogram waveform produced | generated by the said electrocardiogram generation means in the timing of the stimulation by the said nerve stimulation means . A nerve stimulation means for generating a stimulation pulse for stimulating the vagus nerve,
An electrocardiogram generating means for detecting an electrical signal from the heart and generating an electrocardiogram waveform;
Storage means for storing a noise waveform included in the electrocardiogram waveform generated by the electrocardiogram generation means;
A correction electrocardiogram generation unit that corrects the electrocardiogram waveform generated by the electrocardiogram generation unit using a noise waveform stored in the storage unit and generates a corrected electrocardiogram waveform;
The nerve stimulation means generates a stimulation pulse based on the corrected electrocardiogram waveform generated by the correction electrocardiogram generation means;
The corrected electrocardiogram generation means adds a noise inversion waveform obtained by inverting the noise waveform stored in the storage means to the electrocardiogram waveform generated by the electrocardiogram generation means in accordance with the timing of the stimulation by the nerve stimulation means. Te, nerve stimulation device that generates a correction ECG waveform. A nerve stimulation means for generating a stimulation pulse for stimulating the vagus nerve,
An electrocardiogram generating means for detecting an electrical signal from the heart and generating an electrocardiogram waveform;
Storage means for storing a noise waveform included in the electrocardiogram waveform generated by the electrocardiogram generation means;
A correction electrocardiogram generation unit that corrects the electrocardiogram waveform generated by the electrocardiogram generation unit using a noise waveform stored in the storage unit and generates a corrected electrocardiogram waveform;
The nerve stimulation means generates a stimulation pulse based on the corrected electrocardiogram waveform generated by the correction electrocardiogram generation means;
The correction electrocardiogram generation unit generates a correction electrocardiogram waveform by subtracting the noise waveform stored in the storage unit from the electrocardiogram waveform generated by the electrocardiogram generation unit in accordance with the timing of the stimulation by the nerve stimulation unit. be that God through stimulation device.

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