JP2016140582A - Skin barrier function measuring circuit and electronic apparatus including skin barrier function measuring circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a skin barrier function measuring circuit capable of highly accurately measuring a skin barrier function in every state of the skin, and electronic apparatus including the skin barrier function measuring circuit.SOLUTION: The skin barrier function measuring circuit includes: an AC wave generating circuit for generating an AC signal; an application electrode for applying the AC signal; a detection electrode for detecting a signal from the application circuit, transmitting through the skin; a detection circuit for detecting a signal based on the AC signal and adjusting the waveform; a computing unit for controlling the AC wave generating circuit or detecting an output signal from the detection circuit and executing calculation; and a determination circuit for detecting the signal based on the AC signal, determining the magnitude of the signal, and outputting a switching signal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a skin barrier function measuring circuit and an electronic apparatus having the skin barrier function measuring circuit, and more particularly to a measuring circuit for measuring the skin barrier function in all states.

A conventional skin barrier function measuring circuit will be described. FIG. 13 is a block diagram showing a conventional skin barrier function measuring circuit. The conventional skin barrier function measurement circuit includes a display device 1601, a calculator 1602, a signal generator 1603, an application electrode 1604, a detector 1605, and a detection electrode 1606.
After the application electrode 1604 and the detection electrode 1606 are brought into contact with the skin, an AC signal is generated by the signal generator 1603 and the AC signal is applied from the application electrode 1604 to the skin. The AC signal passes through the skin surface stratum corneum 1607 and the epidermis layer 1608 in the skin, and then is detected by the detector 1605 via the detection electrode 1606. The detected signal is processed by the calculator 1602, and the stratum corneum barrier function is calculated and displayed on the display 1601 (see, for example, Patent Document 1).

FIG. 14 is a block diagram showing an electronic apparatus having a conventional skin barrier function measuring circuit. The electronic device includes a main body portion 1701, a display portion 1702, a probe 1703, a detection electrode 1704, and an application electrode 1705.
An electrical signal generated from the application electrode 1705 passes through the skin, and the passed signal is detected via the detection electrode 1704. The detected electric signal is subjected to a predetermined calculation process in a calculation unit built in the main body 1701, and a characteristic value that can serve as a stratum corneum barrier function is calculated based on the calculated susceptance, admittance, and the like. And a characteristic value is displayed on the display part 1702, and it uses as a numerical value showing a skin barrier function (for example, refer patent document 2).

JP 2003-310567 A JP 2010-172543 A

However, it is difficult for conventional electronic devices that measure the skin stratum corneum barrier function to accurately measure the skin barrier function in all skin conditions such as rough skin where the stratum corneum has been peeled off from a normal state. It was difficult to measure.
On the other hand, the present invention provides a skin barrier function measuring circuit and an electronic device having a skin barrier function measuring circuit capable of accurately measuring the skin barrier function in all skin states.

That is, the present invention provides an AC wave generation circuit that generates an AC signal, an application electrode that applies the AC signal, a detection electrode that detects a signal transmitted through the skin from the application electrode, and a signal based on the AC signal. A detection circuit that detects and adjusts the waveform; an arithmetic unit that controls the AC wave generation circuit or detects an output signal from the detection circuit; performs an operation; detects the signal based on the AC signal; The present invention relates to a skin barrier function measurement circuit comprising: a determination circuit that determines the thickness and outputs a switching signal.
The present invention also relates to an electronic device including the skin barrier function measuring circuit.

  The electronic device having the skin barrier function measuring circuit and the skin barrier function measuring circuit of the present invention can accurately measure the skin barrier function in all skin conditions such as rough skin from which the stratum corneum has been peeled off from a normal state.

It is a block diagram which shows the electronic device which has the skin barrier function measurement circuit of 1st embodiment. It is a block diagram which shows the structure of the probe of the electronic device which has the skin barrier function measurement circuit of 1st embodiment. It is a circuit diagram of the skin barrier function measuring circuit of the first embodiment. It is a timing chart which shows operation | movement of the skin barrier function measurement circuit of 1st embodiment. It is a timing chart which shows operation | movement at the time of measuring the rough skin of the skin barrier function measuring circuit of 1st embodiment. It is a circuit diagram of the skin barrier function measuring circuit of a second embodiment. It is a timing chart which shows operation | movement of the skin barrier function measuring circuit of 2nd embodiment. It is a circuit diagram of the skin barrier function measuring circuit of 3rd embodiment. It is a timing chart which shows operation | movement of the skin barrier function measuring circuit of 3rd embodiment. It is a circuit diagram of the skin barrier function measuring circuit of 4th embodiment. It is a circuit diagram of the skin barrier function measuring circuit of 5th embodiment. It is a timing chart which shows operation | movement of the skin barrier function measuring circuit of 5th embodiment. It is a block diagram of the conventional skin barrier function measuring circuit. It is a block diagram showing the electronic device which has the conventional skin barrier function measurement circuit.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<First embodiment>
FIG. 1 is a configuration diagram illustrating an electronic apparatus having a skin barrier function measuring circuit according to the first embodiment. The electronic device having the skin barrier function measuring instrument of the first embodiment includes a main body 101, a display unit 102, a probe 103, and a detection electrode 104. FIG. 2 is a configuration diagram showing the configuration of the probe 103 of the electronic device. The probe 103 includes a detection electrode 104, an application electrode 201, and a ground electrode 202. Here, the ground electrode 202 of the probe 103 prevents external noise from propagating to the detection electrode 104 and the application electrode 201 during measurement, thereby preventing the measurement from being affected by noise.

  FIG. 3 is a circuit diagram of the skin barrier function measuring circuit of the first embodiment. The skin barrier function measurement circuit of the first embodiment includes a computing unit 301, an AC signal generation circuit 310, a signal detection circuit 320, a determination circuit 371, and a ground terminal 300. The computing unit 301 includes output terminals 351, 352, and 353 and input terminals 361 and 362. The AC signal generation circuit 310 includes a 500 Hz AC signal generation circuit 311, a 100 KHz AC signal generation circuit 312, and a switching circuit 313. The switching circuit 313 includes input terminals 314 and 315 and an output terminal 316. The signal detection circuit 320 includes an amplification circuit 321, a filter circuit 322, a current detection circuit 302, and a detection resistor 303.

  Next, connection of the skin barrier function measuring circuit of the first embodiment will be described. In the computing unit 301, the output terminal 351 is connected to the input of a 500 Hz AC signal generation circuit 311, the output terminal 352 is connected to the input of a 100 KHz AC signal generation circuit 312, and the output terminal 353 is connected to the switching circuit 313. Is done. The input terminal 361 is connected to the output of the amplifier circuit 321 and the input of the determination circuit 371, and the input terminal 362 is connected to the output of the determination circuit 371 and the amplifier circuit 321.

  The output of the 500 Hz AC signal generation circuit 311 is connected to the input terminal 314 of the switching circuit 313, and the output of the 100 KHz AC signal generation circuit 312 is connected to the input terminal 315 of the switching circuit 313. An output terminal 316 of the switching circuit 313 is connected to the application electrode 201. The detection electrode 104 is connected to one terminal of the detection resistor 303 and the input of the current detection circuit 302. The other terminal of the detection resistor 303 is connected to the ground terminal 300. The output of the current detection circuit 302 is connected to the input of the filter circuit 322, and the output of the filter circuit 322 is connected to the input of the amplifier circuit 321.

Next, the operation of the electronic apparatus having the skin barrier function measuring circuit of the first embodiment will be described. After turning on the power of the main body 101, the probe 103 on the side surface of the main body 101 is pressed against human skin, the detection electrode 104 and the application electrode 201 are brought into contact with the skin, and a measurement start switch (not shown) )
Then, the skin barrier function measurement circuit inside the main body 101 is operated to measure the impedance in the skin (hereinafter referred to as skin impedance), and the measurement result is converted into a numerical value representing the skin barrier function by the calculator 301. Is displayed on the display unit 102 (see FIG. 1).

  FIG. 4 is a timing chart showing the operation of the skin barrier function measuring circuit of the first embodiment. After the application electrode 201 and the detection electrode 104 are in contact with human skin, the calculator 301 is connected to the output terminal by turning on a measurement start switch (not shown) of the skin barrier function measurement circuit at time t1. A signal for operating the AC signal generation circuit 311 from 351 to 500 Hz is output. At the same time, the computing unit 301 outputs a signal for controlling the switching circuit 313 from the output terminal 353, connects the output of the 500 Hz AC signal generation circuit 311 and the application electrode 201, and causes the application electrode 201 to generate an AC signal of 500 Hz. At the same time, the computing unit 301 is set so that an output signal can be detected from the input terminal 361.

  The 500 Hz AC signal applied from the application electrode 201 is transmitted through the human skin, and the peak value is attenuated or the phase is delayed by the skin impedance, and is detected from the detection electrode 104. A signal from the detection electrode 104 is converted into a response signal by a detection resistor 303 and a current detection circuit 302. This response signal is amplified and shaped into an output signal that can be detected by the arithmetic unit 301 by the amplifier circuit 321 after noise and the like are removed by the filter circuit 322. The computing unit 301 detects the output signal of the amplifier circuit 321 from the input terminal 361, calculates the skin impedance, and uses it as a first measurement value for quantifying the state of the skin barrier function.

Here, there are various states of the human skin such as a rough skin state in which all the stratum corneum has been peeled off from a normal state, an atopy state, and a dry state. For this reason, the skin impedance value also changes in a wide range.
For example, when an AC signal of 500 Hz is applied, the skin impedance changes in the range of 2 KΩ to 20 MΩ between the rough skin where all the stratum corneum has been peeled off and the normal skin. In the case of rough skin where all the stratum corneum of human skin has been peeled off, the signal of the detection electrode 104 is amplified and shaped by the signal detection circuit 320 as shown in FIG. The value appears as a waveform that is cut at certain parts. This occurs because the output limit of the amplifier circuit 321 has been exceeded.

  At this time, the determination circuit 371 determines that the output signal based on the AC signal of 500 Hz exceeds the output limit of the amplifier circuit 321, and before the output signal exceeds the maximum value, the amplifier circuit 321 and the arithmetic unit 301. A signal for switching the gain of the amplifier circuit 321 is output. As a result, the gain of the amplification circuit 321 is reduced, and the arithmetic unit 301 performs remeasurement. As a result, the output signal is prevented from exceeding the output limit of the amplifier circuit 321, and the arithmetic unit 301 can detect an accurate output signal.

  At time t2 in FIG. 4, since the output signal based on the 500 Hz AC signal has exceeded the output limit of the amplifier circuit 321, the output signal after the gain change of the amplifier circuit 321 is shown. When the output limit of the amplifier circuit 321 is exceeded, this output signal is detected by the computing unit 301, and the skin impedance is calculated and used as a first measurement value for quantifying the state of the skin barrier function.

  After the arithmetic unit 301 detects the first measurement value, a signal for operating the 100 KHz AC signal generating circuit 312 is output from the output terminal 352 of the arithmetic unit 301 as shown at time t3, and a 500 Hz AC signal is output from the output terminal 351. A signal for stopping the generation circuit 311 is output. At the same time, the computing unit 301 outputs a signal for controlling the switching circuit 313 from the output terminal 353, connects the output of the 100 KHz AC signal generation circuit 312 and the application electrode 201, and causes the application electrode 201 to generate an AC signal of 100 KHz.

  At the same time, the computing unit 301 is switched so that an output signal can be detected from the input terminal 361. Here, when generating an AC signal of 100 KHz, the current consumption of the skin barrier function measuring circuit can be reduced by stopping the operation of the 500 Hz AC signal generating circuit 311.

  The 100 KHz AC signal applied from the application electrode 201 passes through the human skin and is detected from the detection electrode 104. A signal from the detection electrode 104 is converted into a response signal by the detection resistor 303 and the current detection circuit 302. After the noise and the like are removed by the filter circuit 322, the response signal is amplified and shaped into an output signal that can be detected by the arithmetic unit 301 by the amplifier circuit 321. The computing unit 301 detects this output signal and uses it as a second measurement value for calculating the skin barrier function.

Here, as with the application of a 500 Hz AC signal, when a 100 KHz AC signal is applied, the skin impedance value varies in a wide range depending on the skin condition. For example, the skin impedance is normal from rough skin with all the stratum corneum peeled off. Skin impedance varies between 200Ω and 200KΩ between skins. When the skin layer is rough and peeled off, the maximum value of the output signal from the input terminal 361 appears as a waveform that is cut at a fixed portion, similar to when a 500 Hz AC signal is applied. .
The determination circuit 371 determines that the maximum value of the output signal based on the 100 KHz AC signal exceeds the output limit of the amplifier circuit 321. That is, the determination circuit 371 outputs a signal for switching the gain of the amplification circuit 321 to the amplification circuit 321 and the arithmetic unit 301 before the output signal exceeds the maximum value, thereby reducing the gain of the amplification circuit 321, and the arithmetic unit 301. To perform remeasurement. As a result, the output signal is prevented from exceeding the output limit of the amplifier circuit 321, and the arithmetic unit 301 can detect an accurate output signal.

  At time t4 in FIG. 4, since the output signal based on the 100 KHz AC signal has exceeded the output limit of the amplifier circuit 321, the output signal after the gain change of the amplifier circuit 321 is shown. This signal is detected by the calculator 301 and used as a second measurement value for calculating the skin barrier function.

  According to the skin barrier function measuring circuit of the first embodiment, since the determination circuit 371 is provided, the signal that can be detected by the computing unit 301 regardless of the skin state, that is, the first The measured value and the second measured value can be accurately measured. As a result, it is possible to accurately measure the skin barrier function in various states such as a rough skin state in which all the stratum corneum has been peeled off from a normal state, an atopy state, and a dry state. Also, the current consumption of the skin barrier function measuring circuit is reduced by stopping the operation of the 100 KHz AC signal generation circuit when generating a 500 Hz AC signal and stopping the operation of the 500 Hz AC signal generation circuit when generating a 100 KHz AC signal. Can be made.

  In the skin barrier function measurement circuit according to the first embodiment, the determination circuit 371 employs a method for determining that the output signal exceeds the output limit of the amplifier circuit 321, but is not limited to this method. Any method may be used as long as it can accurately and accurately detect the output signal, such as determining that the signal detection voltage limit of the arithmetic unit 301 has been exceeded. Further, the skin impedance when an AC signal of 500 Hz or 100 KHz is applied is not limited to the described range, and may be an impedance value in any range. Further, the switching of the gain of the amplifier circuit 321 is not limited to once, and may be switched any number of times. In addition, the skin barrier function measuring circuit of the first embodiment adopts a configuration that detects that the voltage of the output signal is high and changes the gain, but detects that the voltage of the output signal is low and changes the gain. You may employ | adopt the structure to do. Moreover, although the AC signal uses frequencies of 500 Hz and 100 KHz, the present invention is not limited to this frequency, and any frequency may be used.

  Further, when the 100 kHz AC signal is oscillating, the operation of the 500 Hz alternating current signal generation circuit 311 is stopped, but it may be kept operating. One signal detection circuit converts 500Hz and 100KHz signals into output signals, but other circuits use two circuits, 500Hz signal detection circuit and 100KHz signal detection circuit. May be. At this time, when a signal of 500 Hz is detected, the operation of the signal detection circuit for 100 KHz may be stopped to reduce current consumption. In addition, although one determination circuit is used to determine the output signals of 500 Hz and 100 KHz, the output signal based on the AC signal of 500 Hz and 100 KHz is determined by two or more determination circuits and a signal for changing the gain is output. May be.

  Furthermore, the skin barrier function measuring circuit of the first embodiment is measured by the electronic device shown in FIG. 1, but the electronic device is not limited to this configuration, and the electronic device can incorporate the measurement probe and the skin barrier function measuring circuit. If so, it may be mounted on any electronic device such as a mobile phone, a smartphone, or a watch. Furthermore, the configuration of the probe 103 is not limited to the configuration shown in FIG. 2 and may be any configuration as long as it can detect an AC signal applied to the skin. Furthermore, the ground electrode 202 need not be used if the influence of external noise during measurement can be reduced.

<Second Embodiment>
FIG. 6 is a circuit diagram of a skin barrier function measuring circuit of the second embodiment. FIG. 7 is a timing chart showing the operation of the skin barrier function measuring circuit of the second embodiment. The skin barrier function measuring circuit of the second embodiment is the skin of the first embodiment in that the output of the determination circuit 371 is connected to the 500 Hz AC signal generating circuit 311, the 100 KHz AC signal generating circuit 312 and the input terminal 362. Different from the barrier function measurement circuit. Others are the same as in the first embodiment, and the main body and the probe to be used are also the same. For this reason, the same code | symbol was attached | subjected about the structure which is common in the skin barrier function measuring circuit of 1st embodiment. Hereinafter, the difference from the skin barrier function measurement circuit of the first embodiment in the skin barrier function measurement circuit of the second embodiment will be mainly described, and the description of the common configuration will be omitted.

As described above, when the skin layer of the person to be measured has rough skin such as all the skin is peeled off, the signal of the detection electrode 104 is amplified and shaped by the signal detection circuit 320, and then the output signal of the input terminal 361 is output. Appears as a waveform that is cut at a constant portion.
On the other hand, in the skin barrier function measuring circuit of the second embodiment, the determination circuit 371 determines that the output signal based on the AC signal of 500 Hz exceeds the output limit of the amplifier circuit 321, and the output signal Before the value exceeds the maximum value, a signal for reducing the peak value of the 500 Hz AC signal is output to the 500 Hz AC signal generating circuit 311 and the calculator 301 (time t2 in FIG. 7). Then, the peak value of the 500 Hz AC signal is lowered, and the calculator 301 is caused to perform remeasurement.
When a 100 KHz AC signal is applied, the determination circuit 371 determines that the maximum value of the output signal based on the 100 KHz AC signal exceeds the output limit of the amplifier circuit 321. Then, before exceeding the maximum value of the output signal, a signal for reducing the peak value of the 100 KHz AC signal is output to the 100 KHz AC signal generating circuit 312 and the arithmetic unit 301, and the peak value of the 100 KHz AC signal is reduced (see FIG. 7 at time t4), the arithmetic unit 301 performs remeasurement. Thus, the output signal is prevented from exceeding the output limit of the amplifier circuit 321, and the arithmetic unit 301 can detect an accurate output signal.

  According to the skin barrier function measuring circuit of the second embodiment, since the determination circuit 371 is provided, a signal that can be detected by the computing unit 301 regardless of the skin condition can be acquired, and thus normal. The skin barrier function can be accurately measured in various states such as a rough skin state in which all the stratum corneum has been peeled off, a topy state, and a dry state. Further, when a 500 Hz AC signal is generated, the operation of the 100 KHz AC signal generation circuit or the 100 KHz signal detection circuit is stopped, and when a 100 KHz AC signal is generated, the operation of the 500 Hz AC signal generation circuit or the 500 Hz signal detection circuit is stopped. The current consumption of the skin barrier function measuring circuit can be reduced.

  In the skin barrier function measuring circuit according to the second embodiment, the switching of the peak value of the AC signal generation circuit is not limited to once, and may be switched any number of times. The skin barrier function measuring circuit of the second embodiment adopts a configuration that detects that the voltage of the output signal is high and changes the peak value, but detects that the voltage of the output signal is low and detects the peak value. You may employ | adopt the structure which changes.

<Third embodiment>
FIG. 8 is a circuit diagram of a skin barrier function measuring circuit of the third embodiment. FIG. 9 is a timing chart showing the operation of the skin barrier function measuring circuit of the third embodiment. The skin barrier function measuring circuit of the third embodiment is different from the skin barrier function measuring circuit of the first embodiment in that the detection resistor 303 is changed to detection resistors 902 and 903 and a switching circuit 901 is added. Others are the same as in the first embodiment, and the main body and the probe to be used are also the same. For this reason, the same code | symbol was attached | subjected about the structure which is common in the skin barrier function measuring circuit of 1st embodiment. Hereinafter, the difference from the skin barrier function measuring circuit of the first embodiment in the skin barrier function measuring circuit of the third embodiment will be mainly described, and the description of the common configuration will be omitted.

  In the skin barrier function measuring circuit according to the third embodiment, the detection electrode 104 is connected to the input terminal of the switching circuit 901 and the input of the current detection circuit 302. The detection resistor 902 has one terminal connected to the first output terminal of the switching circuit 901 and the other terminal connected to the ground terminal 300. The detection resistor 903 has one terminal connected to the second output terminal of the switching circuit 901 and the other terminal connected to the ground terminal 300. The output of the determination circuit 371 is connected to the input terminal 362 and the switching circuit 901, and the connection of the switching circuit 901 is switched.

  In the skin barrier function measuring circuit of the third embodiment, after the application electrode 201 and the detection electrode 104 are brought into contact with human skin, a measurement start switch (not shown) of the skin barrier function measuring circuit is shown at time t1. 1) is turned on, the computing unit 301 outputs a signal for operating the 500 Hz AC signal generation circuit 311 from the output terminal 351. At the same time, the arithmetic unit 301 outputs a signal for controlling the switching circuit 313 from the output terminal 353, connects the output of the 500 Hz AC signal generation circuit 311 and the application electrode 201, and causes the application electrode 201 to generate a 500 Hz AC signal. At the same time, the arithmetic unit 301 is set so that an output signal can be detected from the input terminal 361, and the determination circuit 371 outputs a signal for connecting the detection resistor 902 and the detection electrode 104 to the switching circuit 901.

  The 500 Hz AC signal applied from the application electrode 201 is transmitted through the human skin, and the peak value is attenuated or the phase is delayed by the skin impedance, and is detected from the detection electrode 104. The signal from the detection electrode 104 is converted into a response signal by the detection resistor 902 and the current detection circuit 302, and after the noise is removed by the filter circuit 322, the response signal is output that can be detected by the arithmetic unit 301 by the amplifier circuit 321. Amplified and shaped into a signal. Then, the computing unit 301 detects the output signal of the amplifier circuit 321 from the input terminal 361 and calculates the skin impedance, which is used as a first measurement value for quantifying the state of the skin barrier function.

As described above, when the skin of the person to be measured is rough skin, the maximum value of the output signal of the input terminal 361 is a waveform cut at a certain portion.
On the other hand, in the skin barrier function measuring circuit according to the third embodiment, the determination circuit 371 determines that the output signal based on the AC signal of 500 Hz exceeds the output limit of the amplification circuit 321, and Before the output signal exceeds the maximum value, a signal for switching the detection resistor is output to the arithmetic unit 301 and the switching circuit 901. The computing unit 301 switches the switching circuit 313 from the output terminal 353 so that the application electrode 201 becomes the ground. Thereafter, the switching circuit 901 switches from the detection resistor 902 to the detection resistor 903 to lower the detection resistance value. The arithmetic unit 301 outputs a signal for connecting the output of the 500 Hz AC signal generating circuit 311 and the application electrode 201 from the output terminal 353, and then causes the arithmetic unit 301 to perform remeasurement. Thus, the output signal is prevented from exceeding the output limit of the amplifier circuit 321, and the arithmetic unit 301 can detect an accurate output signal. By stopping the application of an AC signal from the application electrode to the skin when switching the detection resistor, it is possible to prevent the transient noise generated at the time of switching from being transmitted to the human skin and feeling pain.

  At time t2 in FIG. 9, since the output signal based on the 500 Hz AC signal has exceeded the output limit of the amplifier circuit 321, the output signal after the detection resistor is changed is shown. When the output limit of the amplifier circuit 321 is exceeded, this signal is detected by the computing unit 301, and the skin impedance is calculated and used as a first measurement value for quantifying the state of the skin barrier function.

  After the arithmetic unit 301 detects the first measurement value, a signal for operating the 100 KHz AC signal generation circuit 312 is output from the output terminal 352 of the arithmetic unit 301 as shown at time t3, and a 500 Hz AC signal is generated from the output terminal 351. A signal for stopping the circuit 311 is output. At the same time, a signal for controlling the switching circuit 313 is output from the output terminal 353 of the computing unit 301, the output of the 100 KHz AC signal generation circuit 312 and the application electrode 201 are connected, and the application electrode 201 generates a 100 KHz AC signal. At the same time, the computing unit 301 is set to detect an output signal, and the determination circuit 371 outputs a signal for connecting the detection resistor 902 and the detection electrode 104 to the switching circuit 901.

  The 100 KHz AC signal from the application electrode 201 passes through the human skin and is detected from the detection electrode 104. A signal from the detection electrode 104 is converted into a response signal by the detection resistor 902 and the current detection circuit 302. The response signal is noise-removed by the filter circuit 322 and then amplified by the amplifier circuit 321 to an output signal that can be detected by the arithmetic unit 301. Then, the calculator 301 detects the output signal of the amplifier circuit 331 and uses it as a second measurement value for calculating the skin barrier function.

  As described above, even when an AC signal of 100 KHz is applied, if the skin of the person to be measured is rough skin, the maximum value of the output signal of the input terminal 361 is a waveform that is cut at a constant portion. appear. On the other hand, in the skin barrier function measuring circuit according to the third embodiment, the determination circuit 371 determines that the output signal based on the 100 KHz AC signal exceeds the output limit of the amplifier circuit 321 and outputs the output signal. Before the signal exceeds the maximum value, a signal for switching the detection resistor is output to the arithmetic unit 301 and the switching circuit 901. The computing unit 301 switches the switching circuit 313 from the output terminal 353 so that the application electrode 201 becomes the ground. Thereafter, the detection circuit is switched from the detection resistor 902 to the detection resistor 903 by the switching circuit 901 to lower the detection resistance value. The computing unit 301 outputs a signal for connecting the output of the 100 kHz AC signal generation circuit 312 and the application electrode 201 from the output terminal 353, and then causes the computing unit 301 to perform remeasurement. Thus, the output signal is prevented from exceeding the output limit of the amplifier circuit 321, and the arithmetic unit 301 can detect an accurate output signal. By stopping the application of an AC signal from the application electrode to the skin when switching the detection resistor, it is possible to prevent the transient noise generated at the time of switching from being transmitted to the human skin and feeling pain.

  At time t4 in FIG. 9, since the output signal based on the 100 kHz AC signal has exceeded the output limit of the amplifier circuit 331, the output signal after the detection resistor is changed is shown. This signal is detected by the calculator 301 and used as a second measurement value for calculating the skin barrier function. Thus, the first measurement value and the second measurement value can be measured accurately and accurately, and the skin barrier function can be calculated from the first measurement value and the second measurement value.

  According to the skin barrier function measuring circuit of the third embodiment, since the determination circuit 371 is provided, a signal that can be detected by the arithmetic unit 301 regardless of the skin condition can be acquired, and thus normal. The skin barrier function can be accurately measured in various states such as a rough skin state in which all the stratum corneum has been peeled off, a topy state, and a dry state. Further, when the AC signal of 500 Hz is generated, the operation of the 100 KHz AC signal generation circuit is stopped, and when the AC signal of 100 KHz is generated, the operation of the 500 Hz AC signal generation circuit is stopped, thereby reducing the current consumption of the skin barrier function measuring circuit. Can be made. Further, by stopping the generation of an AC signal from the application electrode when switching the detection resistor, it is possible to prevent the skin from feeling pain due to noise at the time of switching.

  In the skin barrier function measuring circuit according to the third embodiment, switching of the resistance value of the detection resistor is not limited to once, and may be switched any number of times. In addition, the skin barrier function measuring circuit of the third embodiment adopts a configuration that detects that the voltage of the output signal is high and changes the detection resistance value, but detects and detects that the voltage of the output signal is low. You may employ | adopt the structure which changes resistance value. Further, the AC signal is stopped from being generated from the application electrode 201 when the detection resistor is switched. However, if the transient noise generated when the detection resistor is switched is small, the AC signal may not be stopped.

<Fourth embodiment>
FIG. 10 is a circuit diagram of a skin barrier function measuring circuit of the fourth embodiment. The skin barrier function measurement circuit of the fourth embodiment differs from the skin barrier function measurement circuit of the first embodiment in that the input of the determination circuit 371 is changed to the detection electrode 104. Others are the same as in the first embodiment, and the main body and the probe to be used are also the same. For this reason, the same code | symbol was attached | subjected about the structure which is common in the skin barrier function measuring circuit of 1st embodiment. Even with the configuration of the skin barrier function measuring circuit of the fourth embodiment, the skin barrier function can be accurately measured in various states such as a rough skin in which the stratum corneum is completely peeled off from a normal state. In addition, the output of the determination circuit 371 may output a signal so as to change the peak value or the detection resistance value of the AC signal, as in the second embodiment or the third embodiment.

  According to the skin barrier function measuring circuit of the fourth embodiment as described above, the skin barrier function can be accurately performed in various states such as a rough skin state in which all the stratum corneum has been peeled off from a normal state, an atopy state, and a dry state. Can be measured. Further, when a 500 Hz AC signal is generated, the operation of the 100 KHz AC signal generation circuit or the 100 KHz signal detection circuit is stopped, and when a 100 KHz AC signal is generated, the operation of the 500 Hz AC signal generation circuit or the 500 Hz signal detection circuit is stopped. The consumption current of the skin barrier function measuring circuit can be reduced. Further, by stopping the generation of an AC signal from the application electrode when switching the detection resistor, it is possible to prevent the skin from feeling pain due to noise at the time of switching.

<Fifth embodiment>
FIG. 11 is a circuit diagram of a skin barrier function measuring circuit of the fifth embodiment. FIG. 12 is a timing chart showing the operation of the skin barrier function measuring circuit of the fifth embodiment. The skin barrier function measuring circuit of the fifth embodiment is different from the skin barrier function measuring circuit of the first embodiment in that an amplifier 1301 is added. Others are the same as in the first embodiment, and the main body and the probe used are also the same. For this reason, the same code | symbol was attached | subjected about the structure which is common in the skin barrier function measuring circuit of 1st embodiment. Hereinafter, the difference from the skin barrier function measurement circuit of the first embodiment in the skin barrier function measurement circuit of the fifth embodiment will be mainly described, and the description of the common configuration will be omitted.

  In the skin barrier function measuring circuit of the fifth embodiment, the amplifier 1301 has a non-inverting input terminal connected to the output terminal 316 of the switching circuit 313, an inverting input terminal connected to the detection electrode 104, and an output terminal applied. Connected to the electrode 201. The determination circuit 371 has an input connected to the application electrode 201 and an output connected to the input terminal 362 and the amplifier circuit 321 of the computing unit 301. The input of the current detection circuit 302 is connected to the application electrode 201.

  In the skin barrier function measuring circuit of the fifth embodiment, after the application electrode 201 and the detection electrode 104 are brought into contact with human skin, a measurement start switch (not shown) of the skin barrier function measuring circuit at time t1. Is turned on, the computing unit 301 outputs a signal for operating the 500 Hz AC signal generation circuit 311 from the output terminal 351. At the same time, the arithmetic unit 301 outputs a signal for controlling the switching circuit 313 from the output terminal 353, and connects the output of the 500 Hz AC signal generation circuit 311 and the non-inverting input terminal of the amplifier 1301.

  An AC signal of 500 Hz is output from the output terminal of the amplifier 1301, and the 500 Hz AC signal passes through the human skin from the application electrode 201 and is detected from the detection electrode 104. When the 500 Hz AC signal from the application electrode 201 passes through the human skin, the peak value is attenuated or the phase is delayed by the skin impedance, and is detected from the detection electrode 104. The amplifier 1301 detects this signal and controls the waveform of the signal at the output terminal so that the signal at the non-inverting input terminal and the signal at the inverting input terminal are the same. For example, when the peak value of the signal appearing at the detection electrode 104 is high or the phase is delayed compared to the AC signal because the skin impedance is high, the amplifier 1301 increases the peak value of the signal at the output terminal of the amplifier 1301 or advances the phase. The output is controlled so that the waveform of the signal at the non-inverting input terminal and the signal at the inverting input terminal are the same.

At time t2 in FIG. 12, since the output signal based on the 500 Hz AC signal has exceeded the output limit of the amplifier circuit 321, the output signal after the gain change of the amplifier circuit 321 is shown. When the output limit of the amplifier circuit 321 is exceeded, this signal is detected by the computing unit 301, and the skin impedance is calculated and used as a first measurement value for quantifying the state of the skin barrier function.
After the first measurement value is detected, the arithmetic unit 301 outputs a signal for operating the 100 KHz AC signal generation circuit 312 from the output terminal 352 of the arithmetic unit 301 as shown at time t3, and generates a 500 Hz AC signal from the output terminal 351. A signal for stopping the circuit 311 is output. At the same time, the arithmetic unit 301 outputs a signal for controlling the switching circuit 313 from the output terminal 353, and connects the output of the 100 KHz AC signal generation circuit 312 and the non-inverting input terminal of the amplifier 1301.

  An AC signal of 100 KHz is output from the output terminal of the amplifier 1301, and the AC signal of 100 KHz is detected from the detection electrode 104 through the application electrode 201 through the human skin. When the 100 KHz AC signal from the application electrode 201 passes through the human skin, the peak value is attenuated or the phase is delayed by the skin impedance, and is detected from the detection electrode 104. The amplifier 1301 detects this signal and controls the waveform of the signal at the output terminal so that the signal at the non-inverting input terminal and the signal at the inverting input terminal are the same. For example, when the skin impedance is high and the peak value of the signal appearing on the detection electrode 104 decreases or the phase is delayed compared to the AC signal, the amplifier 1301 increases the peak value of the signal at the output terminal of the amplifier 1301 or advances the phase. And control so that the waveform of the signal at the non-inverting input terminal and the signal at the inverting input terminal are the same.

  The signal from the applied electrode 201 is converted into a response signal by the detection resistor 303 and the current detection circuit 302. The response signal can be detected by the arithmetic unit 301 by the amplifier circuit 321 after noise and the like are removed by the filter circuit 322. Amplified and shaped into an output signal. Then, the computing unit 301 detects the output signal of the amplifier circuit 321 from the input terminal 361 and calculates the skin impedance, which is used as a second measurement value for quantifying the state of the skin barrier function.

  At time t4 in FIG. 12, since the output signal based on the 100 kHz AC signal has exceeded the output limit of the amplifier circuit 321, the output signal after the gain change of the amplifier circuit 321 is shown. This signal is detected by the calculator 301 and used as a second measurement value for calculating the skin barrier function. Thus, the first measurement value and the second measurement value can be accurately measured, and can be used as a measurement value for calculating the skin barrier function.

  According to the skin barrier function measuring circuit of the fifth embodiment, the determination circuit 371 determines that the output limit of the amplifier circuit 321 is exceeded based on the output signal of the amplifier 1301. The operator 301 can acquire a signal that can be detected regardless of the state of the skin, so that the skin can be accurately obtained in various states such as a rough skin state where the stratum corneum has been peeled off from a normal state, an atopy state, and a dry state. Barrier function can be measured. In addition, it is possible to determine the output signal using the signal of the applied electrode and switch the gain or the like to accurately measure the skin barrier function with high accuracy.

  The skin barrier function measuring circuit according to the fifth embodiment employs a method in which the determination circuit 371 determines that the output signal of the amplifier 1301 exceeds the output limit of the amplifier circuit 321. The method is not limited to this, and any method may be used as long as the output signal can be detected with high accuracy, such as determining that the output signal of the amplifier 1301 exceeds the signal detection voltage limit of the arithmetic unit 301. The output of the determination circuit 371 may output a signal so as to change the peak value or detection resistance value of the AC signal, as in the second embodiment or the third embodiment. At this time, switching of the gain of the amplifier circuit 321, the peak value of the AC signal, and the detection resistance value is not limited to once, and may be switched any number of times.

A preferred embodiment for carrying out the present invention can also be configured as follows.
[1] An AC wave generation circuit for generating an AC signal, an application electrode for applying the AC signal, a detection electrode for detecting a signal transmitted through the skin from the application electrode, and a signal based on the AC signal are detected and waveformd A detection circuit that adjusts the AC wave, a calculator that controls the AC wave generation circuit or detects an output signal from the detection circuit, and detects the signal based on the AC signal, and determines the magnitude of the signal And a determination circuit that outputs a switching signal, and a skin barrier function measurement circuit.
[2] The skin barrier function measuring circuit according to [1], wherein the detection circuit includes an amplifier circuit that adjusts a waveform of the signal based on the AC signal, and changes a gain of the amplifier circuit according to the switching signal.
[3] The skin barrier function measuring circuit according to [1], wherein the AC wave generating circuit changes a peak value of the AC signal according to the switching signal.
[4] The skin barrier function measuring circuit according to [1], wherein the detection circuit includes a detection resistor for detecting the signal based on the AC signal, and changes a resistance value of the detection resistor according to the switching signal. .
[5] The skin barrier function measuring circuit according to [4], wherein the computing unit stops applying the AC signal from the application electrode before changing a resistance value of the detection resistor.
[6] The skin barrier function measuring circuit according to any one of [1] to [5], wherein the determination circuit detects the output signal, determines the magnitude of the output signal, and outputs the switching signal.
[7] The determination circuit detects the signal transmitted through the skin from the application electrode, determines the magnitude of the signal transmitted through the skin from the application electrode, and outputs the switching signal. [5] The skin barrier function measuring circuit according to any one of [5].
[8] The skin barrier function measuring circuit further includes an amplifier having a non-inverting input terminal connected to the output of the AC wave generating circuit, an inverting input terminal connected to the detection electrode, and an output terminal connected to the application electrode. And the skin barrier function measuring circuit according to [1].
[9] The skin barrier function measuring circuit according to [8], wherein the determination circuit detects an output of the amplifier, determines a magnitude of a signal output from the amplifier, and outputs a switching signal.
[10] The skin barrier function measuring circuit according to [9], wherein the detection circuit includes an amplifier circuit that adjusts a waveform of the signal based on the AC signal, and changes a gain of the amplifier circuit according to the switching signal.
[11] The skin barrier function measuring circuit according to [9], wherein the detection circuit includes a detection resistor for detecting the signal based on the AC signal, and changes a resistance value of the detection resistor in accordance with the switching signal. .
[12] The AC wave generation circuit includes a first AC signal generation circuit, a second AC signal generation circuit, an output of the first AC signal generation circuit, and an output of the second AC signal generation circuit. The skin barrier function measuring circuit according to any one of [1] to [11], further comprising a switching circuit that is connected and switches connection to the application electrode in accordance with a signal from the computing unit.
[13] When the computing unit is generating a signal based on the signal of the first AC signal generation circuit or the signal of the first AC signal generation circuit at the application electrode, the second AC signal When the operation of the generation circuit is stopped and a signal based on the signal of the second AC signal generation circuit or the signal of the second AC signal generation circuit is generated on the application electrode, the first AC signal The skin barrier function measuring circuit according to [12], wherein operation of the generating circuit is stopped.
[14] An electronic device comprising the skin barrier function measuring circuit according to any one of [1] to [13] and a display unit for displaying a calculation result in the skin barrier function measuring circuit.

DESCRIPTION OF SYMBOLS 101 Main body part 102 Display part 103 Probe 104 Detection electrode 201 Application electrode 202 Ground electrode 300 Ground terminal 301 Calculator 302 Current detection circuit 303,902,903 Detection resistor 310 AC signal generation circuit 311 500Hz AC signal generation circuit 312 100KHz AC signal generation Circuits 313, 901 Switching circuit 320 Signal detection circuit 321 Amplifier circuit 322 Filter circuits 316, 351, 352, 353 Output terminals 314, 315, 361, 362 Input terminal 371 Determination circuit 1301 Amplifier

Claims (10)

An AC wave generating circuit for generating an AC signal;
An application electrode for applying the AC signal;
A detection electrode for detecting a signal transmitted through the skin from the application electrode;
A detection circuit for detecting a signal based on the AC signal and adjusting a waveform;
An arithmetic unit for performing calculation by detecting an output signal from the control of the AC wave generation circuit or the detection circuit;
A determination circuit that detects the signal based on the AC signal, determines the magnitude of the signal, and outputs a switching signal;
A skin barrier function measuring circuit comprising:   The skin barrier function measuring circuit according to claim 1, wherein the detection circuit includes an amplifier circuit that adjusts a waveform of the signal based on the AC signal, and changes a gain of the amplifier circuit according to the switching signal.   The skin barrier function measuring circuit according to claim 1, wherein the AC wave generating circuit changes a peak value of the AC signal in accordance with the switching signal.   The skin barrier function measurement circuit according to claim 1, wherein the detection circuit includes a detection resistor for detecting the signal based on the AC signal, and changes a resistance value of the detection resistor in accordance with the switching signal.   The skin barrier function measuring circuit according to any one of claims 1 to 4, wherein the determination circuit detects the output signal, determines the magnitude of the output signal, and outputs the switching signal.   5. The determination circuit according to claim 1, wherein the determination circuit detects the signal transmitted through the skin from the application electrode, determines the magnitude of the signal transmitted through the skin from the application electrode, and outputs the switching signal. The skin barrier function measuring circuit according to claim 1. The skin barrier function measuring circuit further includes
A non-inverting input terminal is connected to the output of the AC wave generation circuit, an inverting input terminal is connected to the detection electrode, and an output terminal is connected to the application electrode.
The skin barrier function measuring circuit according to claim 1, wherein the determination circuit detects an output of the amplifier, determines a magnitude of a signal output from the amplifier, and outputs a switching signal.   The skin barrier function measuring circuit according to claim 7, wherein the detection circuit includes an amplifier circuit that adjusts a waveform of the signal based on the AC signal, and changes a gain of the amplifier circuit according to the switching signal.   8. The skin barrier function measuring circuit according to claim 7, wherein the detection circuit includes a detection resistor for detecting the signal based on the AC signal, and changes a resistance value of the detection resistor in accordance with the switching signal. A skin barrier function measuring circuit according to any one of claims 1 to 9,
An electronic apparatus comprising a display unit for displaying a calculation result in the skin barrier function measuring circuit.

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