JP2004049536A - Pulsing electrostimulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulsing type electrostimulator which eliminates pain and an uncomfortable feeling due to electric stimulation, enables simultaneous acquisition of the effect of stimulation by a high-frequency and that by a low-frequency and executes a safe and effective treatment. <P>SOLUTION: The frequency of pulses of the electrostimulator is made to correspond to a muscular refractory period. The frequency is modulated with a frequency of the refractory period or below and the frequency of the pulses is varied in a wide range of the refractory period so that the stimulation by the low-frequency can be performed simultaneously with the stimulation by the high-frequency. An electric current during the stimulation is monitored and controlled so that it may not becomes large beyond a prescribed range. Thereby the safe electric stimulation can be performed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial application fields]
The present invention relates to a pulse electrical stimulation device that applies a pulse current to a human body to perform muscle stimulation, pain relief, etc., and in particular, there is little sharp irritation and pain due to pulse stimulation, and low frequency while stimulating in a high frequency region. An object of the present invention is to provide a pulse-type electric stimulation device that can obtain a therapeutic feeling of the above, and that is safe and can simultaneously obtain immediate effect and persistence in pain relief.
[0002]
[Prior art]
The pulse-type electrical stimulator uses a low-frequency pulse current output from an oscillator to flow through a conductor to the affected area, and stimulates the pulse current waveform, pulse width, frequency, energization time, and rest time. Various parameters such as polarity can be set by operating a mode switch.
A pulse width of about several tens to several hundreds μs is usually used. On the other hand, the frequency (pulse frequency) is used in the low frequency treatment device from near zero to 1000 Hz, mainly about 100 Hz or less.
[0003]
In the stimulation with a frequency of 20 to 30 Hz or less, the muscle repeats contraction and relaxation following each pulse, but when the frequency is higher than that, the muscle cannot follow the pulse stimulation and maintains the contracted state. The period in which the muscle reaction does not follow the pulse is called the refractory period.
Here, with a frequency of 20 to 30 Hz as a boundary, a frequency higher than this is set as a frequency in the refractory period or a frequency corresponding to the refractory period, and a frequency lower than this is set as a frequency below the refractory period.
[0004]
In pain relief, a high frequency of several tens Hz or more is used to obtain an immediate effect, and a low frequency of several Hz is used to obtain a continuous effect.
In addition, there are two methods for pain relief: a method of contracting muscles and a weak stimulation method that does not contract. However, contraction of muscles also has an indirect effect other than the direct action of current, which improves blood flow and relieves pain. Therefore, usually, a method of performing stimulation while contracting muscles is frequently used.
For this reason, there are those that stimulate the low-frequency region mainly, those that stimulate the high-frequency region, and those that sweep from the low-frequency region to the high-frequency region.
[0005]
Skin impedance depends on the frequency, and the higher the frequency, the lower the impedance.
When the frequency of the pulses is low, the muscles repeatedly contract and relax in response to individual pulses, resulting in a physical shock. Moreover, since the impedance is high, when the output is increased, pain and an unpleasant irritation sensation occur, and it is therefore difficult to supply a large amount of energy.
On the other hand, when the frequency is high, there are few unpleasant stimuli and a lot of energy can be supplied.
[0006]
In electrical stimulation, there is also a problem that the output becomes excessive and pain and burns occur. Although the output is supplied to the living body through the conductor, if the contact between the conductor and the skin is insufficient, the treatment is often performed by increasing the output voltage to flow a desired current. While the stimulation is continued in this state, when the contact is improved by sweating or the like and the impedance of the load is lowered, an excessive current flows, causing pain and burns. In particular, in an electrical stimulation device using a metal local stimulation electrode, this risk is high because the metal electrode is used in contact with dry skin.
[0007]
[Problems to be solved by the invention]
In the conventional low-frequency region, i.e., a stimulus with a frequency lower than the refractory period, a shock-like unpleasant stimulus or pain may occur.
Further, since pulses are output at a low frequency in time series, it takes time for stimulation and there is a limit to improving efficiency. Furthermore, there were differences in the therapeutic effect depending on the ratio of the amount of stimulation between the wide area and the low area.
On the other hand, in an electrical stimulation device using a metal local stimulation electrode, contact failure with the skin is likely to occur, and there is a risk that excessive current flows and pain and burns occur.
[0008]
[Means for Solving the Problems]
In order to solve these problems, in the invention according to claim 1, the frequency f of the output pulse of the electrical stimulation device is set to a frequency corresponding to the refractory period of the muscle, and this is frequency-modulated with a frequency δf equal to or lower than the refractory period, The frequency f is changed in a wide range of the refractory period, and a stimulus is given at a low frequency δf while stimulating at a high frequency f.
According to the second aspect of the present invention, in the pulse electrical stimulation device using the metal local stimulation electrode, the current value I0 at the start of stimulation is stored, the current value is monitored during stimulation, and the current during stimulation The output is controlled so that does not change beyond a predetermined range from the current at the start of stimulation.
[0009]
[Action]
According to the first aspect of the present invention, since the living body is stimulated by frequency-modulating a high frequency of the refractory period with a low frequency below the refractory period, the living body can be stimulated simultaneously at both the high frequency and the low frequency. For this reason, there are few unpleasant irritation | stimulation like a pain and a shock, a big energy can be supplied, and the low frequency muscle stimulation effect can fully be acquired. In addition, it is possible to obtain a stimulation sensation associated with a frequency change, and to obtain both an immediate effect and a sustained effect of pain relief at the same time.
According to the second aspect of the present invention, control is performed so that the output does not change greatly even when the impedance of the load changes during stimulation. For this reason, troubles such as pain, unpleasant irritation, and burns can be prevented, and safe irritation can be performed.
[0010]
【Example】
According to the first aspect of the present invention, the pulse frequency f of the stimulator is set to a frequency corresponding to the refractory period of the muscle, and this is frequency-modulated with a frequency δf that is equal to or lower than the refractory period. While changing greatly between fH and stimulating at a high frequency f, a feeling of stimulation is simultaneously produced at a low frequency δf.
[0011]
FIG. 1 shows a state of frequency control according to the present invention.
In this example, fL is set to 100 Hz, fH is set to 1 kHz, and at first, it is linearly changed between 100 Hz and 1 kHz over 1 second. The next time is 900 ms, the next time is 800 ms, and the last time is 100 ms. That is, δf is frequency-modulated by changing from 1 Hz to 10 Hz.
100 Hz or higher is a frequency corresponding to the refractory period of muscle. On the other hand, the frequency below 10 Hz is a frequency below the refractory period. For this reason, there are few unpleasant shock-like irritation | stimulations and pains, a sufficiently low-frequency irritation can be obtained, and the muscles can be sufficiently contracted. Since the low frequency stimulation is performed simultaneously with the high frequency stimulation, the immediate effect and the sustained effect of analgesia can be obtained at the same time.
Since the frequency of the pulse is 100 Hz or more, the skin impedance is smaller than that of a conventional stimulus of 100 Hz or less, and therefore, large electric energy can be supplied.
The frequency is changed from 100 Hz to 10 kHz, 1 kHz. By giving such a frequency change, the difference in stimulation sensation can be sufficiently identified. In this frequency band, it is better to empirically change the frequency within the range of several times. Thereby, the habituation at the time of electrical stimulation can also be prevented.
[0012]
In this embodiment, fL is set to 100 Hz and fH is set to 1 kHz, but the present invention is not limited to this value. Since the frequency may correspond to the muscle refractory period, fL may be about 20 to 30 Hz or more, and fH may be larger than fL and may be 1 kHz or more. If it is desired to obtain a difference in stimulation sensation as the frequency changes, fH should be several times greater than fL.
Moreover, although fL and fH showed the example fixed to 100 Hz and 1 kHz, you may make it change arbitrarily. This can also reduce habituation.
In this embodiment, an example of linearly increasing / decreasing from 100 Hz to 1 kHz has been described, but the rate of change may be arbitrary.
[0013]
In the embodiment, δf is changed to 1 to 10 Hz, but may be fixed or changed. The range of change may be larger or smaller. It may be a constant frequency. In short, it may be below the frequency of the refractory period.
In this example, the pulse frequency is changed between 100 to 1000 Hz while changing the frequency δf, and the stimulation is continuously performed. However, an arbitrary pause (output zero) period may be provided at an arbitrary timing. . Intermittent stimulation may be performed with a pause period for each low frequency period or for each of a plurality of periods. An example of this is shown in FIG. FIG. 2A is an example in which a pause period is provided for each low frequency period while performing the frequency modulation of FIG.
In FIG. 2B, 10 stimulations shown in FIG. 1 are set as one group, and a rest period is provided after the group stimulation. However, it is not necessary to make 10 stimulations as one group, and any number of stimulations can be made into one group.
[0014]
In the low-frequency treatment device, if the electrode contact is poor at the start of stimulation, the impedance of the load is high. Therefore, the stimulation is performed with a higher voltage than usual and a predetermined current. Then, during stimulation, the impedance decreases due to sweating or the like, and the current increases. Therefore, an excessive current flows, and pain or burns may occur. This danger is particularly noticeable in electrical stimulation devices using metal local stimulation electrodes.
Therefore, the invention according to claim 2 stores the current value at the time of starting the stimulus, monitors the current value during the stimulus, and outputs the current during the stimulus so that the current during the stimulus does not change beyond a predetermined range. It is intended to control.
[0015]
An embodiment of the claimed invention is shown in FIG. The figure is a graph of current when actually controlled.
The current value I0 when the output is set and stimulation is started is stored in memory. During stimulation, the current is measured every certain time and compared with I0. When the current exceeds the allowable range beyond I0, the voltage is lowered to reduce the current. FIG. 3 is an example in which the voltage is controlled at the point where the current changes stepwise four times in this way so that the current falls within a predetermined range. There may be a case where the current decreases from the initial value, but this is also a phenomenon that occurs when the electrode is peeled off by electrical stimulation, so there is a risk of burns if the current is increased in such a case. Therefore, it is better to avoid increasing the current if possible.
By doing so, the current can be kept within a predetermined range from the value at the start of stimulation, so that excessive current does not flow and safe stimulation with less burns and pain can be performed. it can.
[0016]
【The invention's effect】
According to the first aspect of the present invention, stimulation is performed at a high frequency corresponding to the refractory period of the muscle, and this is frequency-modulated at a low frequency equal to or lower than the refractory period. Thus, the muscle does not respond to high frequency individual pulses, but responds to low frequency changes. That is, high frequency and low frequency stimuli can be obtained simultaneously. Moreover, since the frequency of the pulse is high, the skin impedance is low and a large amount of electric energy can be supplied.
For this reason, there is no intense reaction such as contraction and relaxation during low-frequency pulse stimulation, and there is little pain or shock-like irritation. Since the muscle contracts slowly and reliably with a low frequency change, a sufficient muscle stimulation effect can be obtained.
Moreover, the analgesic sustained effect by the low frequency stimulation and the immediate effect of the analgesia by the high frequency stimulation can be obtained at the same time.
Furthermore, a high therapeutic effect can be obtained efficiently.
[0017]
According to the second aspect of the present invention, the current value at the start of stimulation is stored, and even if the load impedance changes greatly during the treatment, the current does not change greatly. It is possible to prevent problems such as pain and burns from occurring.
[Brief description of the drawings]
FIG. 1 shows an example of frequency modulation of an electrical stimulation device according to claim 1;
FIG. 2 is another example of frequency modulation of the electrical stimulation device according to claim 1;
(A) is an example in which one frequency-modulated stimulation wave is a group, (B) is a group of a plurality of stimulation waves, and a rest period is provided between the groups.
FIG. 3 is an example of current control of the electrical stimulation device according to claim 2;

Claims (2)

In a pulse-type electrical stimulation device having a frequency f,
The frequency f is a frequency corresponding to the refractory period of the muscle, and this is frequency-modulated with a frequency δf equal to or lower than the frequency corresponding to the refractory period,
The frequency f is changed in a wide range between the low frequency fL and the high frequency fH in the refractory period region,
A pulse electrical stimulation device that gives a feeling of stimulation at a low frequency δf while stimulating at a high frequency f. 2. The pulse electrical stimulation device according to claim 1, wherein the metallic local stimulation electrode is used, the current value I0 at the start of the stimulation is stored, the current value is monitored during the stimulation, and the current I0 and the stimulation current at the start A pulse electrical stimulation device in which the outputs are controlled so that the current during stimulation does not change beyond a predetermined range from the current I0 at the start of stimulation.

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