JP5818352B2 - Neural stimulation device and control method thereof - Google Patents

Description

  The present invention relates to a nerve stimulation apparatus, and more particularly to a nerve stimulation apparatus that performs treatment by stimulating the vagus nerve and a control method thereof.

2. Description of the Related Art Conventionally, a nerve stimulation device that treats arrhythmia by suppressing an increase in heart rate and sympathetic excitement by applying electrical stimulation to the vagus nerve via an electrode connected to the vagus nerve is known.
Patent Document 1 describes such a nerve stimulation device. In this nerve stimulation apparatus, an electrode lead to which electrical stimulation is transmitted is implanted and placed in a living body in order to make it as close as possible to a target to be stimulated in the living body.

  In the nerve stimulation apparatus described in Patent Document 1, the heart rate is measured by the heart rate measuring means, and the vagus nerve is stimulated when the heart rate exceeds a predetermined threshold. As a heartbeat detecting means, a general electrode installed in the heart is used.

Japanese Patent No. 4563785

However, the nerve stimulation device of Patent Document 1 has a problem that it cannot be said that the invasion given to the patient is small because the heartbeat detecting means is placed in the heart.
On the other hand, although it is conceivable to install a heartbeat detecting means on the body surface, there is a problem that troublesomeness occurs when the number of electrodes to be installed is increased although the invasion is reduced.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a nerve stimulation apparatus and a control method thereof that can reduce invasion and annoyance.

  A first aspect of the present invention is a nerve stimulation apparatus that performs treatment by stimulating a nerve, and includes a stimulation signal generation unit that generates a nerve stimulation signal composed of a plurality of unit pulses, and the nerve stimulation signal to the nerve. Electrical information on a living body is acquired at a plurality of acquisition timings from two electrodes including at least one of the pair of electrodes to be applied and a heart rate is calculated based on the electrical information. A heart rate measuring unit, the electrode unit, a lead unit connecting the stimulation signal generating unit and the heart rate measuring unit, and a control unit for controlling operations of the stimulation signal generating unit and the heart rate measuring unit. The controller is configured to generate the unit pulse by the stimulus signal generation unit between the acquisition timings, and the acquisition timing for the first time after the unit pulse is generated when the unit pulse is generated. Spacing is such that sufficient predetermined value or more to the potential change of the living body caused by the unit pulse disappears, and sets a generation timing of the unit pulse and the acquisition timing.

  The controller is configured such that an interval between the generation of the unit pulse and the first acquisition timing after the unit pulse generation is greater than an interval between the generation of the unit pulse and the acquisition timing immediately before the unit pulse generation. You may set the said acquisition timing and the said generation | occurrence | production timing so that it may become long.

  The nerve stimulation apparatus of the present invention is provided between the lead unit, the stimulation signal generation unit, and the heart rate measurement unit, and the lead unit, the stimulation signal generation unit, and the heart rate measurement unit. There may be further provided a switching section for selectively and switchably connecting.

  According to a second aspect of the present invention, a heart rate measuring unit that acquires electrical information of a living body at a plurality of acquisition timings, calculates a heart rate based on the electrical information, and a nerve stimulation signal including a plurality of unit pulses. And a stimulation signal generator for generating a neurostimulator, wherein the unit pulse has a pulse width set shorter than an interval between the acquisition timings immediately before and immediately after the unit pulse, The acquisition timing is such that the interval between the generation of the pulse and the first acquisition timing after the unit pulse generation is equal to or greater than a predetermined value sufficient to eliminate the potential change of the living body caused by the unit pulse. The generation timing of the unit pulse is set.

  According to the nerve stimulation apparatus and the control method thereof of the present invention, it is possible to reduce invasion and annoyance.

It is a mimetic diagram showing the nerve stimulation device concerning a first embodiment of the present invention. It is a timing chart which shows the relationship between the nerve stimulation signal and the acquisition timing of an electrocardiogram waveform. It is a figure which expands and shows a part of FIG. It is a figure which expands and shows a part of FIG. It is a schematic diagram which shows the nerve stimulation apparatus which concerns on 2nd embodiment of this invention. It is a schematic diagram which shows the state in which the same nerve stimulation apparatus is acquiring the electrocardiogram waveform. It is a timing chart which shows the relationship between the nerve stimulation signal and the acquisition timing of an electrocardiogram waveform. It is a figure which expands and shows a part of FIG. It is a schematic diagram which shows the nerve stimulation apparatus which concerns on the modification of this invention. It is a schematic diagram which shows the nerve stimulation apparatus which concerns on the modification of this invention.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic diagram showing a nerve stimulation apparatus 1 of the present embodiment. The nerve stimulation system 1 is for treating arrhythmia such as tachycardia by stimulating the vagus nerve, and is connected to the stimulus generator 10 that generates a nerve stimulus signal and is placed in a living body. And the lead part 30 that connects the stimulation generator 10 and the electrode part 20 to each other.

  The stimulus generation device 10 according to the present embodiment is a non-implantable device, and includes a heart rate measurement unit 11, a stimulus signal generation unit 12, and a control unit 13 connected to the heart rate measurement unit 11 and the stimulus signal generation unit 12. And an interface unit 14 connected to the control unit 13.

  The heart rate measuring unit 11 acquires the electrical information acquired by the electrode unit 20 at a predetermined timing, and measures the heart rate based on the electrical information. The stimulation signal generation unit 12 generates a nerve stimulation signal having a predetermined pulse width and voltage value at a predetermined timing instructed by the control unit 13. The generated nerve stimulation signal is sent to the electrode unit 20 through the lead unit 30 and applied to the vagus nerve Vn.

  The control unit 13 includes a calculation unit such as a CPU and a storage unit such as a memory, and a timing (acquisition timing) at which the heart rate measurement unit 11 acquires electrical information according to a program stored in the storage unit and a stimulus. The timing at which the signal generation unit 12 generates the nerve stimulation signal is set in a predetermined manner, and is controlled by instructing the heart rate measurement unit 11 and the stimulation signal generation unit 12. Details of this control mode will be described later.

  The interface unit 14 has a known configuration such as a liquid crystal screen (including a touch panel), buttons, and the like, displays the heart rate measured by the heart rate measuring unit 11, and inputs a user's operation input to the stimulus generator 10. Accept and send to control unit 13.

The electrode unit 20 includes a first electrode 21 and a second electrode 22 that form a pair of a positive electrode and a negative electrode. The electrode unit 20 is placed in the patient's body so as to contact the vagus nerve Vn. The first electrode 21 and the second electrode 22 are applied with the nerve stimulation signal generated by the stimulation signal generator 12, and the potential difference between the first electrode 21 and the second electrode 22 is an electrocardiogram waveform ( The information is acquired by the heart rate measuring unit 11 as electrical information). The heart rate measuring unit 11 performs A / D conversion on the electrocardiogram waveform and calculates the RR interval to measure the heart rate. That is, the electrode unit 20 has two types of functions, that is, a function of acquiring electrical information of a patient and a function of applying a nerve stimulation signal.
In order to suitably exhibit the above-described two functions of the pair of electrodes of the electrode unit 20, it is preferable to set the distance between the first electrode 21 and the second electrode 22 to 5 millimeters (mm) or more and 10 mm or less. When the distance is less than 5 mm, the potential difference between the pair of electrodes becomes small, which is insufficient as electrical information, and when the distance exceeds 10 mm, it is not preferable in view of the application of the nerve stimulation signal.

  The lead portion 30 has a known configuration including a lead wire 31 therein, and electrically connects the electrode portion 20 to the heart rate measuring portion 11 and the stimulus signal generating portion 12 in the stimulus generator 10 via the lead wire 31. To do. The lead part 30 is fixed to the stimulus generator 10 by the connector 15.

  As shown in FIG. 1, the heart rate measuring unit 11 and the stimulus signal generating unit 12 are connected in parallel to the electrode unit 20. The voltage appearing in the heart rate measuring unit 11 is about several millivolts (mV), and the stimulus signal generating unit can generate a signal having a magnitude of about 20 volts (V). Input protection circuit. Also, a known filter circuit for removing noise components contained in the input signal is provided.

The operation at the time of use of the nerve stimulation apparatus 1 of the present embodiment configured as described above will be described.
When an operation for starting neural stimulation is input to the interface unit 14 when the patient feels a subjective symptom or the doctor determines that treatment with neural stimulation is necessary, the control unit 13 performs a neural stimulation execution flag. Becomes 1, and nerve stimulation is executed. The control unit 13 controls the stimulation signal generation unit 12 to generate a nerve stimulation signal in a predetermined manner, and controls the heart rate measurement unit 11 to acquire an electrocardiographic waveform from the electrode unit 20 in a predetermined manner. Thereafter, the heart rate measuring unit 11 calculates an RR interval based on the acquired electrocardiogram waveform, further calculates an approximate heart rate from the RR interval, and sequentially displays it on the interface unit 14.

FIG. 2 is a timing chart showing the relationship between the nerve stimulation signal and the electrocardiographic waveform acquisition timing. As shown in FIG. 2, the stimulation of the vagus nerve Vn is performed by repeating the unit cycle with a predetermined length (1 minute in this embodiment) as a unit cycle. The nerve stimulation signal is composed of a plurality of unit pulses P, and is generated by the stimulation signal generation unit 12 based on the set voltage, pulse width, and frequency in a part of the unit cycle (in this embodiment, 10 seconds (sec)). Is done.
Meanwhile, the heart rate measurement unit 11 acquires an electrocardiographic waveform at a predetermined frequency (in this embodiment, 250 hertz (Hz)). In FIG. 2, the electrocardiographic waveform acquisition timing is indicated by Tm.
Since the actual unit pulse P and the acquisition timing Tm are many and difficult to describe accurately, FIG. 2 shows the number of the unit pulses P and the acquisition timing Tm smaller than the actual number. Yes.

  3 is an enlarged view of the range of three unit pulses P in FIG. 2, and FIG. 4 further shows acquisition timings Tm before and after one unit pulse P in FIG. It is an enlarged view. The control unit 13 sets the interval between the unit pulses as the acquisition timing so that the positional relationship between the unit pulse P and the acquisition timing Tm before and after the unit pulse P is fixed while using the frequency preset in the stimulation signal generation unit 12 as a base. Set to an integer multiple of the interval between.

  In the present embodiment, the set frequency of the nerve stimulation signal is 20 Hz (interval between unit pulses 50 milliseconds (ms)), and the frequency of acquisition timing Tm is 250 Hz (interval between acquisition timings 4 ms). The interval between pulses is not an integer multiple of the interval between acquisition timings. Therefore, if each of them is executed at the set frequency, the positional relationship between the unit pulse P and the acquisition timing Tm is not fixed and varies depending on each unit pulse. In this case, although details will be described later, the accuracy of the calculated heart rate may be lowered.

Therefore, the control unit 13 calculates the least common multiple of the interval between the unit pulses and the interval between the acquisition timings, and the interval between the unit pulses is an integral multiple of the interval between the acquisition timings in the time of the least common multiple. In addition, the unit pulse generation timing is set so that the unit pulses are arranged as evenly as possible, and the stimulation signal generator 12 is instructed.
In this embodiment, since the least common multiple of the interval between unit pulses and the interval between acquisition timings is 100 ms, this 100 ms is close to the standard interval of unit pulses 50 ms and is an integral multiple of the interval between acquisition timings 52 ms. The next unit pulse P2 is generated 52 ms after the unit pulse P1, which is the starting point of the count of 100 ms, and the next unit pulse P3 is generated 48 ms later. Thereafter, so as to repeat this cycle, the control unit 13 controls the stimulation signal generation unit 12 so as to generate unit pulses by alternately switching the interval between unit pulses between 52 ms and 48 ms.

  Since 52 ms corresponds to a time corresponding to 13 acquisition timings and 48 ms corresponds to a time corresponding to 12 acquisition timings, in any of the unit pulses P1, P2, and P3, the unit pulse P and the acquisition timing Tm1 before and after the unit pulse P The positional relationship with Tm2 is the same as shown in FIG. 4 and does not change during nerve stimulation. Further, since the interval between unit pulses is alternately switched between 52 ms and 48 ms, at least two unit pulses P always exist during any 100 ms during nerve stimulation. Therefore, although the interval between unit pulses is not completely uniform, the average value is 50 ms, and unit pulses are generated at a frequency of approximately 20 Hz.

As shown in FIG. 4, the pulse width of the unit pulse P is shorter than the interval between the acquisition timings, and at a predetermined position between the acquisition timings Tm1 and Tm2, that is, at a predetermined timing so as not to overlap with the acquisition timings Tm1 and Tm2. Generated. The interval t1 between the unit pulse P and the immediately preceding acquisition timing Tm1 is set shorter than the interval t2 between the unit pulse P and the immediately following acquisition timing Tm2. This is due to the following reason.
When the unit pulse P is applied to the living body, the value of the electrical information of the living body such as an electrocardiogram changes under the influence. For this reason, if the heart rate measurement unit 11 acquires an electrocardiogram waveform in the state where the influence of the unit pulse P remains, there is a possibility that correct heart rate measurement cannot be performed.
In FIG. 4, the potential change pv of the living body caused by the unit pulse P is shown as an image. This occurs when the living tissue is polarized by the unit pulse P and then the potential is released, and becomes a noise for the electrocardiogram waveform. As shown in FIG. 4, the potential change pv occurs after a slight time lag after the application of the unit pulse P, and then disappears after a certain time. Therefore, the intervals t1 and t2 are set so that the acquisition timing Tm2 immediately after the potential change pv accompanying the application of the unit pulse P completely disappears.
The pulse width of the unit pulse P is preferably about 100 microseconds (μs) to 1 ms, and may be adjustable by the user within this range. When the pulse width is larger than 1 ms, it becomes difficult to set the interval t2 suitably depending on the frequency of the acquisition timing.

The suitable length of the interval t2 varies depending on the voltage value of the unit pulse P, the pulse width w1, and the like, but in many cases, it is preferable to secure 2 ms or more. On the other hand, for the interval t1, since the application of the unit pulse P does not affect the electrical information acquired at the acquisition timing Tm1, there is no particular lower limit value and may be as short as possible. As an example, in this embodiment, the voltage value and pulse width w1 of the unit pulse P are set to 5 V and 1 ms, respectively, and the intervals t1 and t2 are set to 0.4 ms and 2.6 ms, respectively.
In the present embodiment, the numerical settings such as the interval are recorded and set in the control unit 13, but instead of this, a separate storage unit may be provided and the setting may be called from the storage unit.

  When the patient or doctor confirms the therapeutic effect while observing the heart rate displayed on the interface unit 14 and determines that the treatment may be terminated, the patient or doctor performs a predetermined stop operation. Thereby, the nerve stimulation execution flag is set to 0 (zero) in the control unit 13, and the treatment by the nerve stimulation device 1 is completed.

  As described above, according to the nerve stimulation device 1 of the present embodiment, the stimulus generation device 10 includes the heart rate measurement unit 11, and the pair of electrode units 21 and 22 of the electrode unit 20 are connected to the heart rate measurement unit 11. Therefore, it is possible to perform both nerve stimulation and electrocardiographic waveform acquisition for heart rate measurement with only the electrode unit 20. Therefore, it is not necessary to attach an electrode for acquiring an electrocardiogram waveform in the heart or on the body surface, and arrhythmia treatment can be performed while reducing the invasion and troublesomeness of the patient.

  Further, since the control unit 13 adjusts the interval between the unit pulses so that the positional relationship between the unit pulse P of the nerve stimulation signal and the acquisition timing Tm before and after the unit pulse P is fixed, the positional relationship between the unit pulse and the acquisition timing is changed. It can always be kept in a suitable state.

  Furthermore, since the interval t2 from the acquisition timing Tm2 immediately after the unit pulse P is set to a length sufficient for the potential change pv to completely disappear, the electrocardiographic waveform acquired at the acquisition timing Tm2 is a potential. It is not affected by the change pv. Therefore, the heart rate can be accurately measured based on the electrical information acquired by the electrode unit 20 even during application of the nerve stimulation signal.

In the present embodiment, the example has been described in which the control unit fixes the positional relationship between the acquisition timing and the unit pulse and adjusts the intervals t1 and t2 by adjusting the generation timing of the unit pulse with the acquisition timing unchanged. Alternatively, the same control may be performed by adjusting the acquisition timing with the unit pulse generation timing unchanged. However, since the number of acquisition timings is significantly larger than that of unit pulses, adjusting the generation timing of unit pulses can simplify the calculation and has the advantage of reducing the load on the control unit.
Furthermore, if the interval t2 is sufficiently secured, the electrocardiographic waveform does not necessarily have to be acquired at a predetermined frequency, and may be performed sporadically, for example.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The difference between the nerve stimulation apparatus 101 of the present embodiment and the nerve stimulation apparatus 1 of the first embodiment is the internal structure of the stimulation generator. In the following description, the same components as those already described are denoted by the same reference numerals and redundant description is omitted.

  FIG. 5 is a schematic diagram showing the nerve stimulation apparatus 101. The configuration is generally the same as that of the nerve stimulation apparatus 1, but is different in that a switching unit 16 is provided in the stimulation generator 10A instead of the input protection circuit. An element such as a relay or a semiconductor switch can be used as the switching unit 16, and the heart rate measuring unit 11 and the stimulus signal generating unit 12 are selectively connected to the lead unit 30 by the switching unit 16. The switching unit 16 is connected to the control unit 13, and the part connected to the lead unit 30 is switched by the control unit 13. With this structure, when applying a nerve stimulation signal, the lead unit 30 and the stimulation signal generation unit 12 are selectively connected as shown in FIG. 5, and when acquiring an electrocardiographic waveform, as shown in FIG. As shown, the lead unit 30 and the heart rate measuring unit 11 are selectively connected.

7 and 8 are timing charts showing the relationship between the nerve stimulation signal and the acquisition timing of the electrocardiographic waveform in the nerve stimulation apparatus 101, and generally correspond to FIG. 3 and FIG. The control mode of the unit pulse P and the acquisition timing Tm in the neurostimulator 101 is except that the interval between the unit pulses P1 and P2 is set to 48 ms, and the interval between the unit pulses P2 and P3 is set to 52 ms. This is the same as the first embodiment.
Further, as shown in FIG. 8, the connection of the switching unit 16 is switched by the control unit 13 so as to correspond to the timing control described above.

Similarly to the first embodiment, the nerve stimulation apparatus 101 of the present embodiment can perform both the application of a nerve stimulation signal and the acquisition of an electrocardiogram waveform for heart rate measurement using only the electrode unit, and the invasion and troublesomeness of the patient. The arrhythmia treatment can be performed with reduced depth.
In addition, since the switching unit 16 is provided instead of the input protection circuit, the heart rate measuring unit 11 can be protected more reliably to friends if the circuit configuration can be simplified.

  The embodiments of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiments, and the combinations of the components or the components may be changed without departing from the spirit of the present invention. It is possible to make various changes to or delete them.

  For example, as in the modification shown in FIG. 9, a third electrode 41 is further provided on the body surface, and an electrocardiographic waveform is acquired between one of the pair of electrodes of the electrode unit 20, for example, the first electrode 21. It is good also as a structure. In this case, although one electrode is installed on the body surface, the troublesomeness of the patient is reduced as compared with the case where a plurality of electrodes are installed on the body surface for acquiring an electrocardiographic waveform as in the conventional case. In this modification, when the third electrode 41 is installed so that the first electrode 21 and the third electrode 41 sandwich the heart Ht, a clearer electrocardiographic waveform can be obtained, and the calculated heart rate Accuracy can be improved.

  FIG. 10 is a modified example in which the third electrode 42 is disposed along the lead portion 30. In this case, although the configuration around the electrode unit is slightly complicated, both the measurement of the heart rate and the application of the nerve stimulation signal are performed simply by placing the electrode unit 20 in the body, as in the above-described embodiments. be able to. Further, since the distance between the first electrode 21 and the third electrode 42 can be set sufficiently long without considering the influence on the application of the nerve stimulation signal, the potential difference between the first electrode 21 and the third electrode 42 can be set. Can be ensured sufficiently, and a clearer electrocardiographic waveform can be obtained more easily than in the above embodiments.

In the modification of FIG. 10, substantially the same effect can be obtained even if the third electrode 42 is left in the body without being along the lead portion 30.
9 and 10, the first electrode 21 shared by the heart rate measuring unit 11 and the stimulus signal generating unit 12 is replaced with the heart rate measuring unit 11 by switching means similar to the switching unit 16. Alternatively, the stimulus signal generator 12 may be selectively and switchably connected.

Furthermore, the frequency of the unit pulse and the frequency of the acquisition timing of the electrocardiographic waveform are not limited to the examples of the embodiments.
Further, by inputting the frequency of the unit pulse or the acquisition timing of the electrocardiographic waveform to the interface unit 14, these frequencies may be set by a user such as a patient or a doctor. Here, based on the input value, the control unit 13 may calculate suitable intervals t1 and t2 and set them in the heart rate measurement unit and the stimulation signal generation unit. Further, when the interval t2 cannot be suitably set because the pulse width of the unit pulse is too long or the acquisition timing frequency is too large, the stimulus generator 10 issues an alarm and prompts the frequency to be re-input. You may comprise as follows.
Furthermore, when the user inputs any of the parameters of the unit pulse frequency, pulse width, and electrocardiographic waveform acquisition timing, the control unit performs calculation so that the interval t2 is optimized, and the remaining parameters are automatically set. You may comprise so that it may set.

  The interval t2 is not necessarily longer than the interval t1 as long as the acquisition timing Tm2 is arranged after the potential change due to the unit pulse has completely disappeared. However, the higher the acquisition timing frequency, the better the heart rate calculation accuracy. There is an advantage that the frequency of the acquisition timing can be increased by making the interval t1 shorter than the interval t2.

  The calculation method by which the heart rate measurement unit calculates the heart rate is not limited to the above method, and various known methods may be applied, and the above-mentioned least common multiple is also used in the setting of the acquisition timing and the unit pulse generation timing. Arithmetic other than the arithmetic method using the may be used.

  In each of the above-described embodiments, the non-implantable stimulus generator is used. However, the present invention is not limited to this, and an implantable stimulus generator may be used. In this case, another device including an interface unit may be prepared, and communication between the control unit and the interface unit may be performed wirelessly or the like.

DESCRIPTION OF SYMBOLS 1,101 Neural stimulation apparatus 11 Heart rate measurement part 12 Stimulus signal generation part 13 Control part 16 Switching part 20 Electrode part 30 Lead part P, P1, P2, P3 Unit pulse Tm, Tm1, Tm2 Acquisition timing

Claims (4)

A nerve stimulation device that stimulates nerves to perform treatment,
A stimulation signal generator for generating a nerve stimulation signal composed of a plurality of unit pulses;
An electrode unit having a pair of electrodes for applying the nerve stimulation signal to the nerve;
A heart rate measurement unit that acquires electrical information of a living body from two electrodes including at least one of the pair of electrodes at a plurality of acquisition timings, and calculates a heart rate based on the electrical information;
A lead portion that connects the electrode portion to the stimulation signal generation portion and the heart rate measurement portion;
A control unit for controlling operations of the stimulation signal generation unit and the heart rate measurement unit;
With
The controller is
During the acquisition timing, the unit pulse is generated by the stimulus signal generator,
And the interval between the occurrence of the unit pulse and the first acquisition timing after the generation of the unit pulse is equal to or greater than a predetermined value sufficient for the potential change of the living body caused by the unit pulse to disappear.
A nerve stimulation apparatus, wherein the acquisition timing and the generation timing of the unit pulse are set.   The controller is configured such that an interval between the generation of the unit pulse and the first acquisition timing after the unit pulse generation is greater than an interval between the generation of the unit pulse and the acquisition timing immediately before the unit pulse generation. The nerve stimulation apparatus according to claim 1, wherein the acquisition timing and the generation timing are set to be longer.   Provided between the lead unit, the stimulation signal generation unit, and the heart rate measurement unit, and selectively and switchably connect the lead unit, the stimulation signal generation unit, and the heart rate measurement unit. The nerve stimulation apparatus according to claim 1, further comprising a switching unit that performs the switching. A heart rate measurement unit that acquires electrical information of a living body at a plurality of acquisition timings, calculates a heart rate based on the electrical information, and a stimulation signal generation unit that generates a nerve stimulation signal composed of a plurality of unit pulses. A method for controlling a neurostimulator comprising:
The pulse width of the unit pulse is set shorter than the interval between the acquisition timings immediately before and immediately after the unit pulse,
The acquisition is performed such that the interval between the generation of the unit pulse and the acquisition timing for the first time after the generation of the unit pulse is equal to or greater than a predetermined value sufficient to eliminate the potential change of the living body caused by the unit pulse. A control method for a nerve stimulation apparatus, characterized in that timing and generation timing of the unit pulse are set

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