Iontophoresis device and iontophoresis method

Abstract

To achieve iontophoresis aiming at the maximum current deliverable to the skin.SOLUTION: An iontophoresis device that introduces ions into a living body through electrical stimulation via electrodes, the device performing current control comprising: a first step in which, when a first mode is defined as a mode in which a cutoff frequency of a low-pass filter is raised stepwise and a second mode is defined as a mode in which the cutoff frequency of the low-pass filter is lowered stepwise, the first mode is executed until a current value shifts from increasing to decreasing; a second step in which, when the current value shifts from increasing to decreasing in the first step, the first mode is switched to the second mode and the second mode is executed until the current value again shifts from increasing to decreasing; and a third step in which, when the current value shifts from increasing to decreasing in the second step, the second mode is switched to the first mode.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an iontophoresis device for introducing ions into a living body. [Background technology]

[0002] Iontophoresis devices that introduce ions into a living body by electrical stimulation via electrodes are known (see, for example, Patent Documents 1 and 2). Because bioimpedance varies depending on the condition of the skin, the environment in which it is used, and the method of using the device (the area in contact with the skin), it has long been a challenge to provide electrical stimulation based on a targeted pulse waveform in real time.

[0003] Patent Document 1 discloses an ionic drug introduction device for introducing an ionic drug through the skin, comprising: electrodes to which the ionic drug is applied and attached to the surface of the skin; current detection means for detecting the value of the current flowing through the electrodes; optimal frequency determination means for measuring the complex dielectric constant of the skin based on the detected current value and determining the optimal frequency corresponding to the measured complex dielectric constant; and pulse voltage application means for generating a pulse voltage at the determined optimal frequency and with a predetermined duty ratio and applying the pulse voltage to the electrodes.

[0004] Patent Document 2 discloses a cosmetic liquid agent penetration device for penetrating an ionic liquid agent into human skin tissue to enhance cosmetic effects, the device comprising: electrodes to which the liquid agent is applied and attached to the skin surface; and pulse voltage application means for generating a pulse voltage having a frequency between 100 kHz and 1000 kHz and a duty ratio between 30% and 50%, and applying the pulse voltage to the electrodes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-11589 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-319474 [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-102851 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to realize iontophoresis that aims at the maximum value of current that can be passed through the skin while monitoring the current value. [Means for solving the problem]

[0007] In order to solve the above problems, the iontophoresis device of the present invention is (1) an iontophoresis device that introduces ions into a living body by electrical stimulation via electrodes, the iontophoresis device comprising: a controller; a voltage signal generation unit for adjusting a peak voltage; an output synthesis unit including at least a low-pass filter; an output unit that outputs a pulse signal synthesized by the output synthesis unit; and an output detection unit that detects a current value output from the output unit and transmits the detected current value to the controller; wherein, when a mode in which the cutoff frequency of the low-pass filter is gradually increased is defined as a first mode, and a mode in which the cutoff frequency of the low-pass filter is gradually decreased is defined as a second mode, the controller performs current control including: a first step of operating the first mode until the current value changes from increasing to decreasing when the current value changes from increasing to decreasing in the first step; a second step of operating the second mode until the current value changes from increasing to decreasing when the current value changes from increasing to decreasing in the second step; and a third step of switching the second mode from the second mode to the first mode when the current value changes from increasing to decreasing when the current value changes from increasing to decreasing in the second step.

[0008] (2) The iontophoresis device described in (1) above, characterized in that the controller performs a first pre-step, which is a preparatory process for passing a weak current through a living body, and then determines whether or not the electrode is in contact with the living body, and if it determines that there is contact, performs a second press step in which a base current having a higher current value than the weak current is passed through the living body, and after the second press step, starts the current control, and the controller determines whether or not there is contact between the electrode and the living body each time it changes the cutoff frequency in the first mode and the second mode, and if it determines that there is no contact, switches from the first mode or the second mode to the first pre-step.

[0009] (3) The iontophoresis device according to (2) above, wherein the controller performs a process of gradually increasing the duty ratio or the peak voltage in the second pre-step.

[0010] (4) The iontophoresis device according to any one of (1) to (3), wherein the controller maintains a constant peak voltage during the first mode and the second mode.

[0011] (5) The iontophoresis device according to (1) or (2) above, characterized in that the first mode and the second mode are implemented by a polarity reversal method in which the polarity of the electrodes alternates.

[0012] (6) An iontophoresis method (excluding medical procedures) for introducing ions into a living body by electrical stimulation via electrodes of an iontophoresis device, the iontophoresis device having a controller, a voltage signal generating unit for adjusting a peak voltage, an output combining unit including at least a low-pass filter, an output unit for outputting a pulse signal combined by the output combining unit, and an output detecting unit for detecting a current value output from the output unit and transmitting the detected current value to the controller, wherein, when a mode for gradually increasing the cutoff frequency of the low-pass filter is defined as a first mode and a mode for gradually decreasing the cutoff frequency of the low-pass filter is defined as a second mode, the controller is caused to perform current control including: a first step of implementing the first mode until the current value changes from increasing to decreasing when the current value changes from increasing to decreasing in the first step; a second step of switching the first mode to the second mode and implementing the second mode until the current value changes from increasing to decreasing when the current value changes from increasing to decreasing in the second step; and a third step of switching the second mode to the first mode when the current value changes from increasing to decreasing when the current value changes from increasing to decreasing in the second step. [Effects of the Invention]

[0013] According to the present invention, by controlling the cutoff frequency while monitoring the increase or decrease in the current value, it is possible to achieve iontophoresis that aims at the maximum value of the current that can be passed through the skin. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. [Figure 2] FIG. 2 is a functional block diagram of the facial beauty device. [Figure 3] 1 is a flowchart of an overall iontophoresis method. [Figure 4] This is a subroutine of the flowchart in FIG. 3 (current control mode). [Figure 5] FIG. 2 is a schematic diagram showing the waveform of a weak current. [Figure 6] FIG. 10 is a schematic diagram showing another waveform of a weak current. [Figure 7] FIG. 2 is a schematic diagram showing the waveform of a base current. DETAILED DESCRIPTION OF THE INVENTION

[0015] Fig. 1 is a perspective view of the exterior of a facial massager, an example of an iontophoresis device. Facial massager 1 includes a housing 2, an introduction electrode 3, a counter electrode 4, a power on switch 5, a power off switch 6, and a battery housing 7. Housing 2 may be made of an insulating material such as synthetic resin. However, the present invention is not limited to facial massagers, and may be any device that can introduce ions into any part of a living body.

[0016] The introduction electrode 3 corresponds to OUT1 in Fig. 2, which will be described later, and outputs a pulse signal to the living body. The counter electrode 4 corresponds to OUT2 in Fig. 2. The facial beauty device 1 operates when the power on switch 5 is operated, and stops when the power off switch 6 is operated.

[0017] In the facial beauty device 1, an absorbent member (not shown) impregnated with ionized cosmetic liquid is interposed between the introduction electrode 3 and the facial area where ions are to be introduced, and ion introduction is initiated by operating the power-on switch 5 while the housing 2 is held in the palm of the hand so as to cover the counter electrode 4. After operation has begun, a pulse signal is output to the introduction electrode 3, allowing the ionized cosmetic liquid in the absorbent member to be introduced into the living body.

[0018] 2 is a functional block diagram of the facial beauty device 1. The facial beauty device 1 includes a controller 10, a voltage signal generating unit 20, an output combining unit 30, an output unit 40, and an output detecting unit 50. The controller 10 controls the entire facial beauty device 1 and may use a microcomputer or the like. The microcomputer may include an I / O (Input / Output), a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc.

[0019] The controller 10 adjusts the peak voltage by controlling the voltage signal generator 20. The peak voltage means the highest voltage within one cycle. The voltage signal for the output pulse generated by the voltage signal generator 20 is sent to the output combiner 30. The output combining unit 30 includes a pulse generating unit 31, a filter control unit 32, and an amplifying unit 33. The controller 10 controls the frequency and duty ratio of the pulse signal by controlling the pulse generating unit 31. The controller 10 controls the cutoff frequency of a low-pass filter included in the filter control unit 32. By controlling the cutoff frequency, the rise time of the pulse signal is adjusted.

[0020] The controller 10 adjusts the frequency, duty ratio, and cutoff frequency of the pulse signal, and then adjusts the peak voltage in the amplifier 33 to generate an output pulse. The generated output pulse is output via the output unit 40. The output detection unit 50 constantly detects the current output from the output unit 40 and outputs the detection result to the controller 10.

[0021] Next, the iontophoresis method using the facial beauty device 1 will be described in detail with reference to the flowcharts of Figures 3 and 4. Figure 3 is a flowchart showing the entire iontophoresis, and Figure 4 is a subroutine corresponding to the power supply control mode (step S104) of Figure 3. It should be noted that the iontophoresis method of the present invention does not include medical procedures.

[0022] 3, when the power-on switch 5 is turned on, the controller 10 performs a "preparatory process" for outputting a pulse signal corresponding to a weak current from the output unit 40 (step S101). Step S101 corresponds to a "first prestep." As will be described later, setting the duty ratio or peak voltage to a low value corresponds to the "preparatory process." The controller 10 determines whether a weak current has flowed based on the detection result of the output detection unit 50 (step S102). If a weak current is detected, it is assumed that the introduction electrode 3 has come into contact with the skin (step S102: Yes), and the process proceeds to step S103. If a weak current has not been detected (i.e., the detected current is 0), step S101 continues. When proceeding to step S103, the controller 10 sets a flag indicating "first skin contact" (hereinafter also referred to as "skin contact flag"). The weak current is set to a low current value that does not make the user aware of the current flowing, and can be determined in advance through experiments using test subjects.

[0023] Here, the controller 10 may generate a weak current by controlling the pulse generating unit 31 to lower the duty ratio. For example, if the reference value of the duty ratio is 50%, a weak current can be generated by setting the duty ratio to a value lower than that. Figure 5 shows a schematic diagram of the waveform of a pulse signal with a lower duty ratio, with the vertical and horizontal axes representing the voltage level and time, respectively.

[0024] In the figure, the output is negative, but the present invention is not limited to this and may be positive, or may be a system in which negative and positive polarity alternate (polarity reversal system) (the same applies to the second pre-step, first mode, and second mode described below). When the output is positive, the positive ion components of the ionized cosmetic liquid are more likely to penetrate the skin, and when the output is negative, the negative ion components of the ionized cosmetic liquid are more likely to penetrate the skin. The polarity reversal system is disclosed, for example, in Patent Document 3.

[0025] Alternatively, the controller 10 may generate a weak current by controlling the amplifier 33 to reduce the peak voltage. In this case, the controller 10 maintains the duty ratio at a reference value. Figure 6 is a diagram showing a waveform of a pulse signal with a reduced peak voltage, with the vertical and horizontal axes representing the voltage level and time, respectively.

[0026] In step S103, a process is performed to change the pulse signal output from the output unit 40 from a pulse signal corresponding to a weak current to a pulse signal corresponding to a base current. The base current has a higher current value than the weak current. The controller 10 can transition from the weak current to the base current by increasing the duty ratio or peak voltage. The base current can be set to an appropriate current value that allows iontophoresis, and can be determined in advance by experiments using subjects.

[0027] Here, it is desirable to perform the above-mentioned transition process by gradually (in other words, stepwise) increasing the duty ratio or peak voltage. By performing this transition process in stages, it is possible to achieve less painful electrical stimulation. That is, if the base current flows immediately after contact with the skin, the electrical stimulation will be painful, so it is desirable to change the current in stages from a weak current to the base current.

[0028] After reaching the base current, the system transitions to current control mode in step S104. As mentioned above, the current that can be passed through the skin varies depending on the condition of the skin (i.e., bioimpedance), the usage environment, the usage method, etc. In current control mode, "current control aiming at the maximum value of the current that can be passed through the skin" is performed, and this current control achieves efficient iontophoresis. The "maximum value of the current that can be passed through the skin" can be experimentally determined by actually performing iontophoresis on multiple subjects, from the perspective of not causing excessive irritation to the skin. Furthermore, "aiming for the maximum value" means "aiming for the maximum value," and does not necessarily mean reaching the maximum value.

[0029] In this embodiment, changing the cutoff frequency is the core of current control. Generally, when the cutoff frequency is increased, the waveform becomes closer to a square wave and the current flow increases. On the other hand, when the cutoff frequency is decreased, the waveform becomes more rounded and the current flow decreases.

[0030] Therefore, to achieve efficient iontophoresis, the basic concept of current control is to gradually increase the cutoff frequency. However, as iontophoresis progresses, increasing the cutoff frequency no longer increases the current value (i.e., the current value changes from increasing to decreasing). This is because the charge accumulated in the living body increases as iontophoresis progresses. In this case, the mode is switched to gradually lowering the cutoff frequency. By lowering the cutoff frequency, the charge discharged from the living body becomes greater than the charge applied to the living body, making it easier for current to enter, and the current value increases despite the lowering of the cutoff frequency. As the discharge from the living body progresses, the current value decreases at a certain point, so the cutoff frequency is raised again to continue iontophoresis. In this way, by controlling the cutoff frequency while monitoring the increase or decrease in the current value, iontophoresis aimed at the maximum current that can be passed through the skin is achieved. The current control mode of the present invention is based on the above findings.

[0031] The current control mode will be described in detail below with reference to the subroutine in Fig. 4. The controller 10 determines whether or not the introducer electrode 3 has come into contact with the skin for the first time based on the above-mentioned skin contact flag (step S201).

[0032] If this is the first skin contact (Yes in step S201), the process proceeds to step S202. In step S202, the controller 10 controls the filter control unit 32 to start iontophoresis with the cutoff frequency increased by one step relative to the base current, and the process proceeds to step S203. By increasing the cutoff frequency, high-frequency bands can be more easily transmitted.

[0033] In step S203, the controller 10 sets the first mode as a state monitoring flag, and the process proceeds to step S105. When setting the first mode in step S203, the controller 10 updates the skin contact flag to change it to "second skin contact."

[0034] In step S105, the controller 10 determines whether the introducer electrode 3 continues to be in contact with the skin. The method of determination is the same as that in step S102, and therefore will not be described again. If the skin contact continues (Yes in step S105), the process proceeds to step S106. If the skin contact is discontinued, the process returns to step S101. When returning to step S101, the controller 10 clears the state monitoring flag and the skin contact flag.

[0035] In step S106, the controller 10 determines whether a predetermined iontophoresis time has elapsed. The iontophoresis time can be set to an appropriate time that achieves the desired iontophoresis in the current control mode. Therefore, if the process proceeds from step S203 to step S105 to step S106, the iontophoresis time has not elapsed, and the process returns to step S201.

[0036] Since the skin contact flag has been updated to "second skin contact," the process returns to step S201 and proceeds to step S204. In step S204, the controller 10 determines whether a predetermined time has elapsed since the cutoff frequency was increased in step S202 (in other words, since the waveform was shaped). The predetermined time is preferably a time equal to or longer than one cycle of the pulse frequency.

[0037] If a predetermined time has passed since the waveform was shaped (Yes in step S204), the process proceeds to step S205. If a predetermined time has not passed since the waveform was shaped (No in step S204), the process proceeds to step S105. After proceeding to step S105, the processes of steps S105, S106, S201, and S204 are repeated until the predetermined time has passed.

[0038] In step S205, the controller 10 determines whether the state monitoring flag is set to the first mode. As described above, since the first mode is set in step S203, the process proceeds to step S206 (step S205 Yes). In step S206, the controller 10 determines whether the current value has increased based on the detection result of the output detection unit 50. If the current value has increased, the process proceeds to step S210. If the current value has not increased, the process proceeds to step S208. If the current value has reached the maximum current, the process also proceeds to step S208. Here, the first step S205 occurs immediately after the transition to the current control mode, and since the charge accumulated in the living body is small, it is usually determined that the current value has increased.

[0039] In step S210, the controller 10 increases the cutoff frequency by another step, and the process proceeds to step S105. Increasing the cutoff frequency increases the current value, thereby facilitating iontophoresis. Here, assuming that the value of the cutoff frequency before the increase is 100%, it is desirable to set the increase amount in one step to about 15 to 25% of that. The same applies to the decrease amount when the cutoff frequency is decreased in a stepwise manner.

[0040] Here, the process of step S105 → step S106 → step S201 → step S204 → step S205 → step S206 → step S210 is repeated for a while (corresponding to the first step). This allows ion introduction to be actively carried out while increasing the current value.

[0041] As time passes and the charge accumulated in the living body increases, the current value detected by the output detection unit 50 changes from increasing to decreasing, and the process proceeds from step S206 to step S208 (step S206 No). In step S208, the controller 10 sets the status monitoring flag to the second mode. That is, the status monitoring flag is updated from the first mode to the second mode, and the process proceeds to step S211.

[0042] In step S211, the controller 10 lowers the cutoff frequency by one step, and the process proceeds to step S105. By lowering the cutoff frequency, the discharged charge becomes greater than the charge applied to the living body, so the charge accumulated in the living body can be gradually reduced while iontophoresis is continued. As described above, when the cutoff frequency is lowered, the current value is reduced by design, but because the charge accumulated in the living body decreases, it becomes easier for the current to flow, and the current value increases.

[0043] That is, after proceeding to step S105, the process of steps S106 → step S201 → step S204 → step S205 → step S207 → step S208 → step S211 is repeated (corresponding to the second step) until it is determined in step S207 that the current value has decreased. When the charge accumulated in the living body has sufficiently decreased, the current value changes from increasing to decreasing (No in step S207), and the process proceeds to step S209.

[0044] In step S209, the controller 10 sets the first mode as a status monitoring flag. That is, the status monitoring flag is updated from the second mode to the first mode, and the process proceeds to step S210 (corresponding to the third step). Here, when the process proceeds from step S209 to step S210, the charge accumulated in the living body has sufficiently decreased, so the current value can be increased by increasing the cutoff frequency. This can promote iontophoresis. Here, in the first and second modes, the controller 10 maintains the peak voltage constant. That is, in the first and second modes, current control is performed by changing the cutoff frequency while maintaining the peak voltage constant, thereby avoiding adverse effects on the living body. [Explanation of symbols]

[0045] 1. Facial beauty device 2. Housing 3 Introducing electrode 4 Counter electrode 5 Power on switch 6 Power off switch 7 Battery compartment 10 Controllers 20 Voltage signal generator 30 Output synthesis unit 31 Pulse generation unit 32 Filter control section 33 Amplification section 40 Output section 50 Output detection unit

Claims

1. An iontophoresis device that introduces ions into a living body by electrical stimulation via electrodes, A controller; a voltage signal generator for adjusting the peak voltage; an output synthesis unit including at least a low-pass filter; an output unit that outputs the pulse signal synthesized by the output synthesis unit; an output detection unit that detects a current value output from the output unit and transmits the detected current value to the controller; and When a mode in which the cutoff frequency of the low-pass filter is increased in stages is defined as a first mode, and a mode in which the cutoff frequency of the low-pass filter is decreased in stages is defined as a second mode, The controller a first step of performing the first mode until the current value changes from increasing to decreasing; a second step of switching from the first mode to the second mode when the current value changes from increasing to decreasing in the first step, and continuing the second mode until the current value changes from increasing to decreasing; a third step of switching the second mode to the first mode when the current value changes from increasing to decreasing in the second step; An iontophoresis device characterized by performing current control including:

2. the controller performs a first pre-step, which is a preparation process for passing a weak current through a living body, and then determines whether or not the electrode is in contact with the living body, and when it determines that contact is occurring, performs a second press step of passing a base current, which has a current value higher than that of the weak current, through the living body, and starts the current control after the second press step; the controller determines whether or not the electrodes are in contact with the living body every time the cutoff frequency is changed in the first mode and the second mode, and when determining that the electrodes are not in contact with the living body, switches from the first mode or the second mode to the first pre-step.

2. The iontophoresis device of claim 1.

3. the controller performs a process of gradually increasing the duty ratio or the peak voltage in the second pre-step.

3. The iontophoresis device according to claim 2.

4. 4. The iontophoresis device of claim 1, wherein the controller maintains a constant peak voltage during the first and second modes.

5. 3. The iontophoresis device according to claim 1, wherein the first mode and the second mode are implemented by a polarity reversal method in which the polarity of the electrodes is alternated.

6. An iontophoresis method (excluding medical procedures) for introducing ions into a living body by electrical stimulation via electrodes of an iontophoresis device, The iontophoresis device comprises: A controller; a voltage signal generator for adjusting the peak voltage; an output synthesis unit including at least a low-pass filter; an output unit that outputs the pulse signal synthesized by the output synthesis unit; an output detection unit that detects a current value output from the output unit and transmits the detected current value to the controller; and When a mode in which the cutoff frequency of the low-pass filter is increased in stages is defined as a first mode, and a mode in which the cutoff frequency of the low-pass filter is decreased in stages is defined as a second mode, to the controller, a first step of performing the first mode until the current value changes from increasing to decreasing; a second step of switching from the first mode to the second mode when the current value changes from increasing to decreasing in the first step, and continuing the second mode until the current value changes from increasing to decreasing; a third step of switching the second mode to the first mode when the current value changes from increasing to decreasing in the second step; An iontophoresis method characterized by carrying out current control including:

Images