JP6014824B1 - Biological stimulator - Google Patents

Abstract

Provided is a biological stimulation device that suppresses stimulation of a living body by a gradually decreasing waveform after a high-frequency switching operation in a short time. The present invention relates to a biostimulation apparatus that outputs a stimulation signal to a living body, an output transformer, a first switch for flowing a current in a predetermined direction to a primary side of the output transformer, and the output transformer. A second switch for flowing a current in a direction opposite to the predetermined direction on the primary side, an output unit for outputting the stimulation signal on the secondary side of the output transformer, and controlling the first switch and the second switch The control unit repeatedly turns on or off one of the first switch and the second switch by the pulse group GP in the group energization period, and then determines the pulse width GP of the pulse group GP. Further, the biostimulation apparatus is characterized in that the other switch is turned on by a pulse P2 having a long pulse width t2. [Selection] Figure 2

Description

  The present invention relates to a biological stimulation device.

  2. Description of the Related Art There is known a biological stimulation device that allows an electric current (stimulation signal) to flow from a conductor (output unit) incorporating an electrode to a living body. In such a living body stimulating device, stimulation is applied to the living body by stimulating nerves or contracting / relaxing muscles by flowing a stimulation signal through the living body. For example, Patent Documents 1 and 2 describe a biological stimulation device that stimulates a living body by outputting a stimulation signal from a conductor connected to a secondary winding of an output transformer.

In the biostimulators described in Patent Documents 1 and 2, a high-frequency pulse group is output to the switching means on the primary side of the output transformer, and a high-frequency stimulation signal is induced on the secondary side of the output transformer.
In the biostimulator described in Patent Document 1, FETs (switch means) are connected to both ends of the primary side winding of the output transformer, and a predetermined voltage is applied to the center tap of the primary side winding. The FET is repeatedly turned on and off by the high frequency pulse group to output a positive high frequency stimulation signal to the secondary side, and then the other FET is repeatedly turned on and off by the high frequency pulse group to reverse polarity to the secondary side. The high-frequency stimulation signal is output.
The biostimulation apparatus described in Patent Document 2 includes two transformers, supplies a high-frequency pulse drive signal to the primary side of one transformer to induce a high-frequency pulse, and low-frequency to the primary side of the other transformer. A low-frequency pulse is induced by supplying a pulse drive signal, and a stimulus signal in which a high-frequency pulse and a low-frequency pulse generated on the secondary side of separate transformers are superimposed is output from a conductor to a living body (note that In the living body stimulation apparatus described in Patent Document 2, since the high-frequency pulse and the low-frequency pulse are superimposed, the group energization period of the high-frequency pulse drive signal to the primary side of one transformer is the primary side of the other transformer. It will overlap with the energization period of the low-frequency pulse drive signal to).

Japanese Patent No. 3503135 Japanese Patent No. 5051625

  While a high-frequency pulse group is input to the primary side of the output transformer, energy due to DC magnetization continues to be accumulated in the output transformer. For this reason, when the input of a high-frequency pulse group to the primary side of the output transformer is turned off, a gradually decreasing waveform that decreases exponentially is induced in the secondary winding by the energy accumulated in the output transformer, and the stimulation signal May be output (described later). This gradually decreasing waveform is a waveform that depends on the characteristics of components (for example, an output transformer and a switching element), and may give an unpleasant stimulus to the living body. In addition, when trying to select a part so as not to cause discomfort due to the gradually decreasing waveform, the cost of the biostimulator is increased.

  An object of this invention is to suppress the irritation | stimulation to the biological body by the gradually decreasing waveform after high frequency switching operation | movement for a short time.

A main invention for achieving the above object is a biological stimulation device that outputs a stimulation signal to a living body, the output transformer, a first switch for flowing a current in a predetermined direction to a primary side of the output transformer, A second switch for flowing a current in a direction opposite to the predetermined direction to the primary side of the output transformer; an output unit for outputting the stimulation signal on the secondary side of the output transformer; the first switch; and the second switch A controller for controlling the switch, and the output transformer accumulates energy during the group energization period when the first switch or the second switch is repeatedly turned on and off by a pulse group of the group energization period, and the group energization period is configured to output a reverse polarity gradually decreasing waveform from the output section immediately after the control unit, one of the first and second switches by pulse group of the group conduction period After repeated on-off switch, within a period of occurrence of the decreasing waveform, by turning on the other switch by a pulse of a pulse width longer than the pulse width of the pulse groups, the immediately said group conduction period The biostimulation apparatus is characterized in that the gradually decreasing waveform output from the output unit is suppressed .

  Other characteristics of the present invention will be made clear by the description and drawings described later.

  ADVANTAGE OF THE INVENTION According to this invention, the irritation | stimulation to the biological body by the gradually decreasing waveform after high frequency switching operation | movement can be suppressed in a short time.

FIG. 1 is an explanatory diagram of the configuration of the biological stimulation device 1 of the present embodiment. FIG. 2 is an explanatory diagram of various signals according to the first embodiment. FIG. 3 is an explanatory diagram of various signals according to the second embodiment. FIG. 4 is an explanatory diagram of various signals according to the third embodiment. FIG. 5 is an explanatory diagram of various signals according to the fourth embodiment. FIG. 6 is an explanatory diagram of various signals of the comparative example.

  At least the following matters will be apparent from the description and drawings described below.

  A biostimulation apparatus that outputs a stimulation signal to a living body, wherein an output transformer, a first switch for causing a current in a predetermined direction to flow to a primary side of the output transformer, and the predetermined direction to a primary side of the output transformer A second switch for flowing a current in the reverse direction, an output unit for outputting the stimulation signal on the secondary side of the output transformer, and a control unit for controlling the first switch and the second switch, The control unit repeatedly turns on or off one of the first switch and the second switch by a pulse group in a group energization period, and then turns on the other switch by a pulse having a pulse width longer than the pulse width of the pulse group. A biological stimulator characterized by being turned on is revealed. According to such a living body stimulating device, it is possible to suppress the stimulation to the living body by the gradually decreasing waveform after the high frequency switching operation in a short time.

  The time from the end of the group energization period in which the one switch is repeatedly turned on / off until the other switch is turned on is preferably equal to or less than the pulse width of the pulse for turning on the other switch. More preferably, it is not more than the pulse width of the pulse group. Thereby, the irritation | stimulation to the biological body by the taper waveform after a high frequency switching operation | movement can be suppressed in a short time.

  The control unit preferably turns on the other switch a plurality of times by a plurality of pulses having a pulse width longer than the pulse width of the pulse group after the group energization period. Thereby, the pulse width of each pulse after a group energization period can be shortened, and the irritation | stimulation to a biological body can be relieved.

  After the group energization period, the control unit turns on the other switch by a pulse having a pulse width longer than the pulse width of the pulse group, and repeats the other switch by a pulse group in the group energization period. After turning on / off, it is desirable to alternately repeat turning on the one switch with a pulse having a pulse width longer than the pulse width of the pulse group. Thereby, the stimulus signal to the living body becomes bipolar.

  Preferably, the controller does not repeatedly turn on / off the pulse group during the group energization period by using the other switch, but preferably repeatedly turns the one switch on / off by the pulse group during the group energization period. . Even in such a case, since it is possible to suppress a direct current from flowing through the living body, it is particularly effective.

=== First Embodiment ===
<Configuration>
FIG. 1 is an explanatory diagram of the configuration of the biological stimulation device 1 of the present embodiment. The symbol R in the figure is a resistance of the human body or a pseudo resistance that simulates the human body resistance. For example, JIS C 6310 stipulates that a 500Ω non-inductive resistor is connected between the output terminals of the biological stimulation device 1.

  The biological stimulation device 1 is a device that gives a stimulus to a living body using a stimulation signal output from the output unit 31. When the current due to the stimulation signal flows through the living body, the nerve is stimulated and the muscle contracts / relaxes, thereby applying the stimulation to the living body. Generally, the higher the frequency of the stimulation signal, the smaller the impedance of the human body and the lesser the muscle stimulation sensation. For example, at a high frequency of 100 kHz or more, muscle stimulation by the stimulation signal is almost eliminated. On the other hand, the lower the frequency of the stimulation signal, the greater the impedance of the human body and the stronger the feeling of stimulation.

  In the biological stimulation device 1 of the present embodiment, the high frequency means a frequency band of approximately several tens of kHz or more. The low frequency means a frequency band of approximately several kHz or less (including a region of several Hz). The frequency of the pulse group GP (see FIG. 2) in the group energization period described later is a high frequency, and the repetition frequency of the group energization period is a low frequency.

  The biological stimulation device 1 includes an output transformer 10, a first switch 21 and a second switch 22, an output unit 31, and a control unit 40.

  The output transformer 10 is a converter (transformer) that converts a signal between a primary side winding and a secondary side winding. The output transformer 10 converts the electric energy supplied to the primary side into magnetic energy, reconverts the magnetic energy into electric energy on the secondary side, and outputs it as a stimulation signal.

In order to transmit a high-frequency signal from the primary side to the secondary side, the number of windings of the output transformer 10 is generally reduced to reduce the inductance of the windings. However, if the number of turns of the output transformer 10 is reduced, there arises a problem that the low frequency signal becomes difficult to be transmitted to the secondary side. On the other hand, if the number of turns is increased in order to transmit a low-frequency signal from the primary side to the secondary side, the impedance at high frequency becomes large, current becomes difficult to flow, and a problem arises that high-frequency characteristics deteriorate. In order to solve such conflicting problems, if high performance permalloy or amorphous is used for the core material of the output transformer 10, the cost increases. Even if another method is adopted such as splitting the primary side winding and secondary side winding and arranging them in a sandwich shape, or connecting multiple windings in parallel instead of a single wire, the cost is high. Will lead to a change.
In contrast, in the present embodiment, a small and inexpensive output transformer 10 using a silicon steel plate as a core is used, and the number of turns is reduced in order to transmit a high-frequency signal to the secondary side. However, as a result, in the present embodiment, the low frequency characteristic and the hysteresis characteristic are sacrificed, and there arises a problem (described later) that the back electromotive voltage in the stored energy increases after the high frequency pulse group is input to the primary side. The core material of the output transformer 10 may be ferrite instead of the silicon steel plate.

  The output transformer 10 includes a first input terminal 11, a second input terminal 12, a center tap 13, a first output terminal 14, and a second output terminal 15. A first input terminal 11, a second input terminal 12, and a center tap 13 are provided on the primary side of the output transformer 10. The first input terminal 11 is a terminal on one end side of the primary side winding. The second input terminal 12 is a terminal on the other end side (the side opposite to the primary input terminal) of the primary side winding. The center tap 13 is a terminal from which an intermediate point of the primary side winding is drawn. A first output terminal 14 and a second output terminal 15 are provided on the secondary side of the output transformer 10.

  The first switch 21 is a switch for causing a positive current (predetermined direction) to flow through the primary winding of the output transformer 10. The first switch 21 is connected to the first input terminal 11 on one end side of the primary winding of the output transformer 10. The first switch 21 is, for example, an FET, and the drain of the FET whose source is grounded is connected to the first input terminal 11, and on / off (energization / pause) control is performed according to a signal input to the gate. It will be. When the first switch 21 is turned on, a positive current flows through the primary winding. When the first switch 21 is turned off, this positive current is cut off.

  The second switch 22 is a switch for flowing a current in the negative direction (the direction opposite to the predetermined direction) through the primary winding of the output transformer 10. The second switch 22 is a switch connected to the second input terminal 12 on the other end side of the primary winding of the output transformer 10 (the side opposite to the side to which the first switch 21 is connected). Similarly to the first switch 21, the second switch 22 is also an FET, for example. The drain of the FET whose source is grounded is connected to the second input terminal 12, and is turned on / off according to a signal input to the gate. It will be. When the second switch 22 is turned on, a negative current flows through the primary winding. When the second switch 22 is turned off, the current in the negative direction is cut off.

  The output unit 31 is an electrode that outputs a stimulation signal to a living body. The output unit 31 is connected to the first output terminal 14 and the second output terminal 15 of the secondary winding of the output transformer 10. The output unit 31 is built in a conductor (for example, an adhesive pad, a suction pad, a metal rod-shaped or glove-shaped conductor) that comes into contact with the living body, and outputs a stimulation signal to the living body via the conductor.

  The control unit 40 is a part (controller) that controls driving of the first switch 21 and the second switch 22. That is, the control unit 40 controls input to the output transformer 10 via the first switch 21 and the second switch 22. The control unit 40 also controls the voltage at the center tap 13 of the primary winding of the output transformer 10. The control unit 40 executes various processes to be described later by executing a program stored in a storage unit (not shown). Here, the control unit 40 includes a processing device 41, a voltage setting unit 42, and a drive signal generation unit 43.

  The processing device 41 is a processing device 41 such as a CPU or MPU. The processing device 41 outputs a setting signal for instructing a setting voltage to the voltage setting unit 42. In addition, the processing device 41 outputs an instruction signal for instructing generation of the first drive signal and the second drive signal to the drive signal generation unit 43.

  The voltage setting unit 42 is a part (circuit) that sets the voltage (set voltage) of the center tap 13 of the output transformer 10. Here, the voltage setting unit 42 includes a D / A converter 42A and an amplifier 42B. The D / A converter 42A outputs a voltage corresponding to the signal input from the processing device 41, and the amplifier 42B amplifies the output voltage from the D / A converter 42A and sets the voltage of the center tap 13. When the setting signal from the processing device 41 is changed, the setting voltage of the center tap 13 of the output transformer 10 is changed, and the voltage of the stimulation signal is adjusted. The voltage setting unit 42 may be configured not to variably configure the set voltage output to the center tap 13 but to output a constant voltage.

The drive signal generation unit 43 is a signal generation unit (circuit) that generates a first drive signal and a second drive signal. The drive signal generator 43 outputs the first drive signal to the first switch 21 (specifically, the gate of the first switch 21 that is an FET), and outputs the second drive signal to the second switch 22 (specifically, the second switch that is an FET). Output to the gate of the switch 22. The control unit 40 may be configured so that the processing device 41 outputs the first drive signal and the second drive signal to the first switch 21 and the second switch 22 without providing the drive signal generation unit 43.
The first drive signal is a signal (drive signal, switch control signal) for driving the first switch 21. When the first drive signal is at the H level, the first switch 21 is turned on, a set voltage is applied to the primary side winding between the first input terminal 11 and the center tap 13 of the output transformer 10, and the primary side winding is applied to the primary side winding. A current in the positive direction (predetermined direction) flows (energization). When the first drive signal is at the L level, the first switch 21 is turned off, and the current in the positive direction is cut off (pause).
The second drive signal is a signal for driving the second switch 22. When the second drive signal is at the H level, the second switch 22 is turned on, a set voltage is applied to the primary winding between the second input terminal 12 and the center tap 13 of the output transformer 10, and the primary winding is applied. A current in the negative direction (the direction opposite to the predetermined direction) flows. When the second drive signal is at the L level, the second switch 22 is turned off, and the current in the negative direction is cut off.

<About various signals>
First, before describing the various signals of the present embodiment, various signals of the comparative example will be described.

■■■ Various signals in the comparative example ■■■
FIG. 6 is an explanatory diagram of various signals of the comparative example. In the figure, the horizontal axis indicates time, and the vertical axis indicates voltage. Various signals in the drawing are a setting signal, a first drive signal, a second drive signal, a virtual stimulus signal for explanation, and a stimulus signal in order from the top.

  The set voltage is the voltage (potential) of the center tap 13 of the output transformer 10. Here, the setting voltage is V1, but the control unit 40 can change the setting voltage V1, and thereby the intensity of the stimulation signal can be adjusted.

  The first drive signal of the comparative example includes a group energization period in which the first switch 21 is switched at a high frequency by the high frequency pulse group GP, and a group inactivity period in which the high frequency pulse group GP is deactivated and the first switch 21 is turned off. Repeat alternately. The high-frequency pulse group GP is a signal that repeats a pulse P having a predetermined pulse width t1 at a high frequency. During the group energization period, a high-frequency pulse group GP is input to the first switch 21, and the first switch 21 is repeatedly turned on and off at a high frequency. Similarly, the second drive signal of the comparative example alternately repeats the group energization period and the group rest period. Since the group energization period of the first drive signal and the group energization period of the second drive signal occur alternately, the first switch 21 and the second switch 22 perform high-frequency switching operations alternately. Note that the group energization period of the first drive signal and the group energization period of the second drive signal do not overlap. When one drive signal is the group energization period, the other drive signal is the group pause period.

  When the first switch 21 (or the second switch 22) is repeatedly turned on and off at a high frequency by the high-frequency pulse group GP, a high-frequency stimulation signal is induced on the secondary side of the output transformer 10. When the first switch 21 is turned on and when the second switch 22 is turned on, the direction of the current on the primary side is reversed. Therefore, a high-frequency stimulation signal having a positive polarity and a negative side Polarity and high-frequency stimulation signals are alternately generated.

By the way, when the pulse P is input to the first switch 21 (or the second switch 22) and the first switch 21 is turned on, the magnetization of the core is generated by the DC current of the primary side winding, and the energy due to this DC magnetization is generated. Is stored in the output transformer 10. When the first switch 21 is turned off after the pulse P is input to the first switch 21 (or the second switch 22), a reverse polarity signal is generated on the secondary side due to the back electromotive force due to the release of the DC magnetization.
When the first switch 21 (or the second switch 22) is repeatedly turned on and off by the high-frequency pulse group GP, energy due to DC magnetization is continuously accumulated. For this reason, when each pulse P of the pulse group GP in the group energization period is at L level (when the switch is off), the voltage of the secondary side stimulation signal is not equal to the reference voltage (0 V) like the virtual stimulation signal. Instead, it gradually increases to the opposite polarity side. That is, the stimulus signal is not a square wave like the virtual stimulus signal in the group waveform GP ′ but a group waveform in which the envelope on the reverse polarity side is gradually increased. Even if the pulse width t1 (energization period) of each pulse P of the high-frequency pulse group GP is short, when the high-frequency pulse group GP is input to the primary side and energy due to DC magnetization is continuously accumulated, at the end of the group energization period, The voltage of the gradually increasing waveform on the reverse polarity side (voltage V3 in the figure) increases.

  When the group energization period in which the first switch 21 (or the second switch 22) is switched at a high frequency ends and the first switch 21 (and the second switch 22) is turned off, the direct current magnetization accumulated in the output transformer 10 Is released, and a gradually decreasing waveform is generated on the reverse polarity side due to the back electromotive force. The stimulus signal of the comparative example in the figure shows that a gradually decreasing waveform is generated that gradually decreases from the reverse polarity voltage V3 to the reference voltage (0V) exponentially immediately after the group energization period.

  Since the gradually decreasing waveform generated after the group energization period has a longer time width than the pulse width t1 of the high-frequency pulse P, it tends to stimulate the living body. In addition, this gradually decreasing waveform is a waveform that depends on the characteristics of the components (for example, the output transformer 10 and the switching element) and is likely to be an unpleasant stimulus to the living body. In particular, as in the present embodiment, when an output transformer 10 having an inexpensive silicon steel plate as a core and a reduced number of turns is used, a gradually decreasing waveform appears remarkably, and the living body is likely to be stimulated. As already described, if it is attempted to select a component whose waveform gradually decreases to the reference voltage so as not to cause discomfort, the cost increases.

  In addition, when the group rest period is short, the next group energization period may occur before the gradually decreasing waveform becomes the reference voltage. In the case of reversing the polarity of the next group energization period, if the next group energization period is reached before the gradually decreasing waveform becomes the reference voltage, the rising voltage (voltage V2 in the figure) of the stimulation signal is reduced. A problem also arises (as a result, a desired feeling of stimulation may not be obtained).

■■■ Various signals of the first embodiment ■■■
FIG. 2 is an explanatory diagram of various signals according to the first embodiment. Various signals in the figure are a setting signal, a first drive signal, a second drive signal, and a stimulus signal in order from the top.

  The first drive signal of the present embodiment alternately repeats a group energization period in which the first switch 21 is switched at a high frequency by the high-frequency pulse group GP and a group pause period in which the high-frequency pulse group GP is paused. The period includes a pulse period in which the first switch 21 is turned on immediately after the group energization period of the second drive signal. Similarly, the second drive signal also repeats the group energization period and the group rest period alternately, and the group rest period includes a pulse period for turning on the second switch 22 immediately after the group energization period of the first drive signal. It is included.

  Similar to the above-described comparative example, in the present embodiment, the group energization period of the first drive signal and the group energization period of the second drive signal are alternately generated. Therefore, the first switch 21 and the second switch 22 have a high frequency. These switching operations are performed alternately. Note that the group energization period of the first drive signal and the group energization period of the second drive signal do not overlap. When one drive signal is the group energization period, the other drive signal is the group pause period.

  On the other hand, unlike the above-described comparative example, in the present embodiment, immediately after the group energization period of the first drive signal, the first drive signal enters the group pause period, the first switch 21 is turned off, and the second drive signal Becomes a pulse period, and the second switch 22 is turned on by a pulse P2 having a predetermined pulse width t2. Similarly, in the present embodiment, immediately after the group energization period of the second drive signal, the second drive signal becomes the group pause period and the second switch 22 is turned off, and the first drive signal becomes the pulse period, One switch 21 is turned on by a pulse P2 having a predetermined pulse width t2. It should be noted that both the first drive signal and the second drive signal become a group rest period after the pulse period until the next group energization period.

  In the present embodiment, the output transformer 10 is driven to a polarity opposite to the polarity of the group energization period in the pulse period immediately after the group energization period. As a result, the energy accumulated in the output transformer 10 during the group energization period is canceled during the pulse period. Therefore, in the stimulation signal of this embodiment, the generation of the gradually decreasing waveform of the stimulation signal of the comparative example (see FIG. 6) is shortened. can do. In addition, the gradually decreasing waveform of the stimulation signal of the comparative example (see FIG. 6) is a waveform depending on the parts, whereas the waveform P2 ′ of the pulse period of the stimulation signal of the present embodiment is based on the controlled waveform. Therefore, it is possible to control the feeling of stimulation given to the living body, and to suppress giving an unpleasant stimulus to the living body. When adjusting the pulse period in order to obtain a desired feeling of stimulation, for example, the number of pulses in the group energization period is adjusted or the duty of the pulses in the group energization period is adjusted in the design stage of the biological stimulation device 1. Or adjust the set voltage.

  The pulse P2 in the pulse period is set to a pulse width t2 that cancels the energy accumulated in the output transformer 10 immediately before. If the first switch 21 (or the second switch 22) is turned on only once with the high-frequency pulse P during the group energization period, the second switch 22 has the same pulse width t1 in order to cancel the energy at that time. (Or the first switch 21) is turned on. In the present embodiment, during the group energization period, the first switch 21 (or the second switch 22) is repeatedly turned on and off by the high-frequency pulse group GP, and energy is continuously accumulated in the output transformer 10. In order to cancel the energy, the pulse P2 in the pulse period needs a pulse width t2 longer than the pulse width t1 (energization period) of each pulse P of the high-frequency pulse group GP in the group energization period (t2> t1). ). In other words, the pulse P2 in the pulse period is a pulse having a lower frequency than the frequency of the pulse group GP in the group energization period.

  By the way, in the above-described comparative example, when the group rest period is short, there is a possibility that the next group energization period may occur before the gradually decreasing waveform becomes the reference voltage (0 V) (as a result, the rising voltage of the stimulation signal (see FIG. 6 voltage V2) may be reduced). In contrast, in the present embodiment, since the generation of a gradually decreasing waveform can be suppressed in a short time, the waveform of the stimulation signal is returned to the reference voltage (0 V) before the next group energization period even if the group pause period is short. be able to.

  In the present embodiment, the end of the group energization period of the first drive signal (start of the group pause period of the first drive signal) and the start of the pulse period of the second drive signal are the same, but not necessarily at the same time. good. However, in order to suppress the stimulation by the gradually decreasing waveform immediately after the group energization period in a short time, from the end of the group energization period of the first drive signal (start of the group pause period of the first drive signal), The time until the pulse period is started (until the second switch is turned on) is preferably not more than the pulse width t2, more preferably not more than the pulse width t1.

By the way, a high-frequency stimulation signal can be expected to have a blood circulation promoting effect, a metabolism promoting effect, and the like. However, the higher the frequency, the smaller the impedance of the human body, and the weaker the stimulation (or no feeling). When the stimulation feeling of the stimulation signal is weak (or insensitive), the user of the biological stimulation device 1 tends to set the amplitude of the stimulation signal excessively in an attempt to increase the stimulation feeling. However, if such a setting (setting that makes the setting voltage V1 excessive) is performed, an overcurrent flows in the human body, which may cause burns to the user.
On the other hand, in this embodiment, after a high-frequency stimulation signal GP ′ in the group energization period, a relatively low-frequency stimulation signal (medium frequency pulse P2 ′) in the pulse period is generated. In other words, in the present embodiment, a pulse P2 ′ having a pulse width t2 longer than the pulse width t1 of the pulse P ′ in the group energization period is generated after the high-frequency stimulation signal GP ′ in the group energization period. Since the impedance of the human body increases as the frequency is lower, even if the feeling of stimulation during the group energization period is weak, it is easy to obtain a feeling of stimulation during the pulse period. Note that the gradually decreasing waveform of the stimulation signal of the comparative example (see FIG. 6) is a waveform depending on the parts, whereas the waveform P2 ′ of the pulse period of the stimulation signal of the present embodiment is a controlled waveform. When the user changes the setting voltage V1 greatly, the user's feeling of stimulation (stimulation feeling due to the waveform of the pulse period) is surely increased. Therefore, in this embodiment, the effect that a user's erroneous operation (operation which sets the setting voltage V1 excessively) can be suppressed is also acquired.

  The control unit 40 may increase or decrease the frequency of the pulse P (pulse of the high-frequency pulse group GP) in the group energization period by controlling the waveforms of the first drive signal and the second drive signal. For example, the frequency of the pulse P may be increased or decreased within the group energization period, or the frequency of the pulse P may be increased or decreased for each group energization period. Further, the frequency of the pulse P may be increased or decreased regularly or randomly. Thus, by increasing or decreasing the frequency of the pulse P in the group energization period, it is possible to create a complex stimulation sensation, and to prevent habituation and improve the treatment effect. Similarly, the control unit 40 increases or decreases the duty of the pulse P of the pulse group GP in the group energization period, increases or decreases the time width or repetition period of the group energization period or the group pause period, and increases or decreases the set voltage. May be. The control unit 40 is configured to be able to change settings of these various parameters based on input information such as a treatment mode and intensity input from an input unit (not shown in FIG. 1) of the biological stimulation device 1. .

=== Second Embodiment ===
In the first embodiment, the pulse P2 (medium frequency pulse P2) in the pulse period is only once. However, since the pulse P2 in the pulse period is set to a pulse width t2 that cancels the energy accumulated in the output transformer 10, if the pulse P2 in the pulse period is only once, the pulse width t2 is relatively long. Will be set. As a result, the waveform P2 ′ of the stimulation signal in the pulse period tends to be low frequency, and there is a possibility that the stimulation to the living body becomes strong. Therefore, in the second embodiment, the pulse P2 in the pulse period is set to a plurality of times (two times or more).

  FIG. 3 is an explanatory diagram of various signals according to the second embodiment. Various signals in the figure are a setting signal, a first drive signal, a second drive signal, and a stimulus signal in order from the top. In addition, the structure of the biostimulation apparatus 1 of 2nd Embodiment is the same as that of 1st Embodiment (refer FIG. 1: other Examples are also the same).

  In the second embodiment, immediately after the group energization period of the first drive signal, the first drive signal becomes the group pause period and the first switch 21 is turned off, and the second drive signal becomes the pulse period, and the second switch 22 is turned on a plurality of times (here, twice) by a pulse P2 (medium frequency pulse P2) having a predetermined pulse width t3. Similarly, immediately after the group energization period of the second drive signal, the second drive signal becomes a group pause period, the second switch 22 is turned off, the first drive signal becomes a pulse period, and the first switch 21 is predetermined. It is turned on a plurality of times (here, twice) by a pulse P2 (medium frequency pulse P2) having a pulse width t3.

  Also in the second embodiment, the output transformer 10 is driven to the opposite polarity side to the polarity of the group energization period in the pulse period immediately after the group energization period. As a result, the energy accumulated in the output transformer 10 during the group energization period is canceled during the pulse period. Therefore, the generation of the gradually decreasing waveform of the stimulation signal of the comparative example (see FIG. 6) is shortened also in the stimulation signal of the second embodiment. Can be on time.

  In the second embodiment, the energy stored in the output transformer 10 is divided into a plurality of times (here, twice) and canceled. For this reason, compared with 1st Embodiment, the pulse width t3 of each pulse P2 of a pulse period can be set short (t3 <t2). Thereby, the waveform P2 'of the stimulation signal in the pulse period has a higher frequency than that of the first embodiment, and the stimulation to the living body can be softened.

  In the second embodiment, there is an L level idle period between the pulses P2 of the pulse period, and the DC magnetization of the output transformer 10 is released during this idle period. As a result, the total pulse width t3 (energization period) of each pulse P2 in the pulse period of the second embodiment can be made shorter than the pulse width t2 of the pulse period of the first embodiment (here, t3 + t3 <t2). That is, in the second embodiment, the energization period of the pulse period can be shortened, and further, the energization period can be divided into a plurality of times to set the pulse width t3, so that the pulse width t3 of each pulse P2 in the pulse period is synergistic. It becomes possible to set to short.

=== Third Embodiment ===
FIG. 4 is an explanatory diagram of various signals according to the third embodiment.
In the third embodiment, in the pulse period immediately after the group energization period of the first drive signal, the pulse P2 (medium frequency pulse P2) having a predetermined pulse width t4 is applied not only to the second drive signal but also to the first drive signal. It has occurred. Also in the pulse period immediately after the group energization period of the second drive signal, the pulse P2 (medium frequency pulse P2) having a predetermined pulse width t4 is generated not only in the first drive signal but also in the second drive signal. Yes. That is, the pulse period of the present embodiment includes not only the pulse P2 having the opposite polarity to the polarity of the immediately preceding group energization period but also the pulse P2 having the same polarity as the polarity of the immediately preceding group energization period.

  In the third embodiment, the number of pulses P2 in the pulse period is an odd number (here, three), and one pulse P2 having a polarity opposite to the polarity of the immediately preceding group energization period is one than the pulse P2 having the same polarity. Become more. This cancels both the energy accumulated in the group energization period and the energy accumulated by the medium frequency pulse P2 on the same polarity side as the polarity of the immediately preceding group energization period by the plurality of medium frequency pulses P2 on the opposite polarity side. Because.

  By the way, in the third embodiment, since the pulse period is set to be relatively long, it is expected that the energy of the output transformer 10 (energy accumulated in the group energization period) is released by the end of the pulse period. it can. For this reason, since the energy required to cancel the energy accumulated in the output transformer 10 during the group energization period can be reduced, the pulse width t4 of each pulse P2 in the pulse period of the third embodiment is equal to the pulse of the first embodiment. It can be made shorter than the pulse width t2 of the period (t4 <t2).

  In the third embodiment, since the stimulation signal in the pulse period is bipolar, it is possible to obtain a feeling of stimulation different from that in the first embodiment or the second embodiment.

=== Fourth Embodiment ===
In the above-described embodiment, the group energization period of the first drive signal and the group energization period of the second drive signal are alternately generated, and the first switch 21 and the second switch 22 alternately perform a high-frequency switching operation. It was. However, it is not limited to such a form.

FIG. 5 is an explanatory diagram of various signals according to the fourth embodiment.
The first drive signal of the fourth embodiment alternately repeats a group energization period in which the first switch 21 is switched at a high frequency by the high-frequency pulse group GP and a group pause period in which the high-frequency pulse group GP is paused. However, in the fourth embodiment, the group energization period is only in the first drive signal, and the second drive signal is not provided with the group energization period by the high-frequency pulse group GP.

  Also in the fourth embodiment, immediately after the group energization period of the first drive signal, the first drive signal is in the group pause period, the first switch 21 is turned off, and the second drive signal is in the pulse period. The switch 22 is turned on by a pulse P2 (medium frequency pulse P2) having a predetermined pulse width t2. For this reason, also in the fourth embodiment, the output transformer 10 is driven to the opposite polarity side to the polarity of the group energization period in the pulse period immediately after the group energization period. As a result, the energy accumulated in the output transformer 10 during the group energization period is canceled during the pulse period, so that the generation of a gradually decreasing waveform of the stimulation signal of the comparative example (see FIG. 6) is shortened also in the stimulation signal of the fourth embodiment. Can be on time.

In the fourth embodiment, unlike the above-described embodiments, the high-frequency switching operation is performed only by the first switch 21, and therefore the polarity of the high-frequency stimulation signal GP ′ is only on one side. In the situation where the polarity of the high-frequency stimulation signal GP ′ is set to one side as in the fourth embodiment, if a gradually decreasing waveform of the stimulation signal of the comparative example (see FIG. 6) is generated without providing a pulse period, the gradually decreasing waveform is Since it occurs only in the polarity on one side, the stimulation signal is in a state where a DC bias is applied. As a result, a direct current continues to flow through the living body, possibly damaging (eg, burning) the cells of the living body.
On the other hand, in the fourth embodiment, since the energy accumulated in the output transformer 10 during the group energization period is canceled during the pulse period, the stimulation signal quickly returns to the reference voltage (0 V). For this reason, in 4th Embodiment, it can suppress that a direct current continues flowing into a biological body, even under the condition where the polarity of the high-frequency stimulation signal is only on one side. As described above, when the high-frequency switching operation is performed only by one switch (for example, the first switch 21) and the polarity of the high-frequency stimulation signal GP ′ is only one side, it is accumulated in the output transformer 10 during the group energization period. It is particularly advantageous to cancel the generated energy with a pulse P2 (medium frequency pulse P2) in the pulse period.

  In the fourth embodiment, the pulse P2 in the pulse period after the group energization period is only once, but the pulse P2 in the pulse period may be plural times as in the second embodiment. In the fourth embodiment, the pulse P2 in the pulse period is only the pulse P2 having a polarity opposite to that of the immediately preceding group energization period, but as in the third embodiment, the pulse having the same polarity as that of the immediately preceding group energization period. P2 may be included.

=== Others ===
The above-described embodiments are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

<About the output transformer 10>
In the above embodiment, the first switch 21 is connected to one end of the primary winding of the output transformer, and the second switch 22 is connected to the other end of the primary winding of the output transformer 10, Since the predetermined voltage V1 is applied to the center tap 13 of the output transformer 10, it is not necessary to divide the primary winding, and the inexpensive output transformer 10 can be used. However, the primary winding of the output transformer 10 may be divided into two.

1 biological stimulation device, 10 output transformer,
11 First input terminal, 12 Second input terminal, 13 Center tap,
14 1st output terminal, 15 2nd output terminal,
21 1st switch, 22 2nd switch,
31 output part (conductor), 40 control part,
41 processing device, 42 voltage setting unit,
42A D / A converter, 42B amplifier,
43 Drive signal generator,
GP high frequency pulse group, P high frequency pulse group pulse,
P2 Medium frequency pulse, R Human resistance

Claims (6)

A biological stimulation device that outputs a stimulation signal to a living body,
An output transformer,
A first switch for flowing a current in a predetermined direction to the primary side of the output transformer;
A second switch for flowing a current in a direction opposite to the predetermined direction on the primary side of the output transformer;
An output unit for outputting the stimulation signal on the secondary side of the output transformer;
A control unit for controlling the first switch and the second switch,
The output transformer accumulates energy in the group energization period when the first switch or the second switch is repeatedly turned on and off by a pulse group in the group energization period, and immediately after the group energization period, the gradually decreasing waveform of the reverse polarity is stored in the output transformer. It is a configuration that outputs from the output unit,
The control unit repeatedly turns on or off one of the first switch and the second switch by a pulse group in a group energization period, and then, within a period in which the gradually decreasing waveform is generated, is greater than a pulse width of the pulse group. The biological stimulation device according to claim 1, wherein the gradually decreasing waveform output from the output unit immediately after the group energization period is suppressed by turning on the other switch with a pulse having a long pulse width. The biostimulator according to claim 1,
The time from the end of the group energization period in which the one switch is repeatedly turned on / off until the other switch is turned on is equal to or less than the pulse width of the pulse for turning on the other switch. Biological stimulation device. The biostimulator according to claim 2,
The biostimulator according to claim 1, wherein a time from the end of the group energization period in which the one switch is repeatedly turned on / off until the other switch is turned on is equal to or less than a pulse width of the pulse group. The biostimulator according to any one of claims 1 to 3,
The control unit turns on the other switch a plurality of times by a plurality of pulses having a pulse width longer than the pulse width of the pulse group after the group energization period. The biostimulator according to any one of claims 1 to 4,
The controller is
After repeatedly turning on and off the first switch by a pulse group in a group energization period, and turning on the second switch by a pulse having a pulse width longer than the pulse width of the pulse group;
Alternately turning on and off the second switch by a pulse group in a group energization period and then turning on the first switch by a pulse having a pulse width longer than the pulse width of the pulse group. A biostimulator that is characterized. The biostimulator according to any one of claims 1 to 4,
The controller repeats turning on and off one of the switches repeatedly by a pulse group in the group energization period, and not repeatedly turning on and off by the pulse group in the group energization period. Biological stimulation device.

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