JPS59148855A - Measuring device for conductance of epidermal horny layer - Google Patents

Abstract

PURPOSE:To measure easily and precisely the conductance of an epidermal horny layer by changing a flat tuning curve according to the conductance of the epidermal horny layer via a quartz oscillator, a buffer amplfier and two sets of tuners and detecting the same. CONSTITUTION:The high frequency output from a quartz oscillator 1 is made into the output of the voltage in which the vltage e2 in the flat tuning curve having a single peak response is equal to the voltage of the high frequency output from a buffer amplifier 2 by a tuner 3 provided with coils 305, 306, coupled coarsely by a critical coupling via the amplifier 2. The output is made into the tuning curve output changing in proportion to the conductance GX corresponding to moisture irrespectively of the capacity Cx of an epidermal horny layer 5 by a tuner 4 provided with a coil 401 having adjusted tap positions. The output from the amplifier 2 and the output from the tuner 4 are processed respectively with detectors 6, 7 and are added to a differential amplifier, then the conductance of the epidermal horny layer having a high correlation with the moisture contained therein is measured easily and precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for easily measuring the conductance of the stratum corneum on the skin surface using the same method.

It is known that there is a certain correlation between the conductance of the stratum corneum and the water content, and if one of them increases, it is known that there is a certain correlation between the conductance and the water content of the stratum corneum. However, such conductance is measured by a complicated method, and diagnosis of the skin surface stratum corneum and accumulation of data regarding the skin surface stratum corneum have been performed solely by knowing the skin surface conductance. Therefore, conventional instruments for measuring the conductance of the stratum corneum of the skin are expensive, have low reliability due to complicated methods, and are inconvenient to handle.

The purpose of the present invention is to precisely adjust the measurement frequency using a crystal oscillator.
The output of the crystal oscillator is set to be stable and the output of the crystal oscillator is loosely coupled to the crystal oscillator. By adding this, a good heavy electric tuning characteristic is realized, and this gives a change to the tuning curve according to the value of the conductance to be measured, and this change is detected by the first and second linear detectors with high impedance. It is an object of the present invention to provide a device which easily and accurately measures the conductance of the stratum corneum of the skin by eliminating the drawbacks of the conventional method by differentially amplifying the difference between the outputs of the re-detector.

The skin surface stratum corneum conductance measuring instrument according to the present invention includes a crystal oscillator, a buffer amplifier, first and second tuners, a measurement electrode section, first and second linear detectors, and a differential amplifier. , and an indicator.

The crystal oscillator is of a type that does not use a constant temperature
It generates the high frequency voltage used for measurements. A buffer amplifier is used to input and amplify a high frequency voltage by loosely coupling a crystal oscillator through a coupling element.

The first tuner is for tuning the output voltage of the buffer amplifier and providing a heavy current open characteristic. The second tuner includes a coil having an intermediate tap for external output, and is used to tune to the output of the first tuner and provide heavy electric characteristics. The measurement electrode section is connected to the intermediate tap and forms a ring-shaped electrode, and is a probe for detecting the conductance of the stratum corneum on the skin surface to be measured. The first linear detector is for detecting the output voltage of the buffer amplifier, and the second linear detector is for detecting the output voltage of the second tuner. The differential amplifier has the first and second
This is to compare the output voltages of the linear wave detectors and generate an output voltage proportional to the difference voltage between the output voltages.

The indicator is for reading the output voltage of the differential amplifier and outputting the conductance of the stratum corneum on the skin surface to be measured.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a conductance measuring device for the stratum corneum of the skin surface according to the present invention, and the measuring device shown in FIG. The device is equipped with detectors 3 and 4, a measurement electrode section 5, a second and second linear detector 6.7, a differential amplifier 8, and an indicator 9.

In FIG. 1, a high frequency voltage generated by a crystal oscillator 1 is passed through a buffer amplifier 2 to a first . and second tuner 3
．． 4 from the second tuner 4 to the measurement electrode section 5.
has been added to. The first and second tuners 3.4 are each composed of passive elements with consideration given to stability,
The Q of each circuit is approximately 20. In the first tuner 3, the coil 305 and the coil 306 are coupled loosely through critical coupling, and the tuning curve exhibits a fairly flat heavy electric characteristic. On the other hand, in the four second tuners, a low impedance branch point is provided in the coil 401. The intermediate tap f is set at both ends of the tuning capacitor so that the impedance division ratio at this branch point is approximately 1/10. A measurement electrode section 5 for measuring the condition of the stratum corneum on the skin surface is connected to this branch point. The measuring electrode section 5 has its center conductor connected to the internal electrode 51 via a lead 53, and its external conductor connected to the ring-shaped external electrode 52. The internal electrode 51 and the external electrode 52 are connected to the skin 5.
4, the conductance of the skin surface stratum corneum between the internal electrode 51 and the external electrode 52 increases in accordance with the moisture contained in the skin surface stratum corneum.

First, before contacting the measurement electrode section 5 with the skin. and the second
The tuner 4.5 of is set to a resonant state, and the signal line 23
It is necessary to adjust the reference high frequency voltage e1 from the signal line 47 and the high frequency voltage e2 across the tuning capacitor from the signal line 47 to be equal to each other. When the measurement electrode section 5 is brought into contact with the skin surface, the conductance Gx of the skin surface stratum corneum is detected at the branch point of the coil 401 in the second tuner, that is, at the intermediate tap f.
, and an associated small capacitance 1 (Cx) are added.

Gx is several tens to hundreds of μmho, and Cx is a value on the order of several 1) F. The conductance Gx of the skin surface stratum corneum is coil 40.
1 and lowers the high frequency voltage e2. Since the capacitance Cx detunes the second tuner 4, it lowers the high frequency voltage e2 in the same manner as above.

FIG. 2 is a tuning curve conceptually drawn with the high frequency voltage e2 plotted on the vertical axis and the tuning capacitance in the second tuner 4 plotted on the horizontal axis. In FIG. 2, curve 10QI shows the tuning curve when no skin surface conductance is added;
02 shows a tuning curve when loss increases due to skin surface conductance. When the measuring electrode part 5 is not brought into contact with the skin surface, the high frequency voltage e2 is at the level shown by a in FIG. 2, and when the measuring electrode part 5 is brought into contact with the skin surface.
Effective QfJ due to the conductance component Gx of the skin surface stratum corneum
<'F therefore follows curve 1'002. In this case, if there is no capacitance component Cx, the high frequency voltage e2 is at a level indicated by b, but if there is a capacitance component Cx, it becomes a level indicated by C.

However, the change in the high frequency voltage e2 due to the above-mentioned capacitance component Cx can be reduced in practical use by optimizing the setting of the branch point in the coil 401, that is, the intermediate tap f, and lowering the effective Q of the second tuner 4. It can be reduced to a level that does not cause any problems.

In this embodiment, the position of the intermediate tap f is selected at ⅓ of the total number of turns of the coil 4°I. Compared to the case where the measurement electrode 5 is directly connected in parallel to the tuning capacitance of the coil 401,
When connecting to a branch point as described above, the change in the high frequency voltage e2 due to the capacitance component is reduced to the impedance division ratio, which in this embodiment is 1/1o. Second
As shown in the figure, the shape of the tuning curve near the resonance point changes quadratically, so the value of the converted capacitance Cx is approximately 1
/1o, the change in the high frequency voltage e2 due to the capacitance Cx becomes approximately 1/100. On the other hand, when the conductance G
The change in the high frequency voltage e2 due to this is proportional to the converted conductance and is approximately 1/1o. In the end, the change in high frequency voltage e2 due to capacitance Cx was relatively improved to about 1/1o compared to the change in high frequency voltage (!2) due to conductance component Gx, at the expense of sensitivity to the conductance component Gx to be measured. On the other hand, it is also effective to lower the effective Q of the first tuner 3.The first tuner 3 is a double-tuned circuit, and the tuning characteristics near the resonance point are better than the normal heavy electric characteristics. is also flat, the capacitance component C
The change in high frequency voltage e2 due to x becomes considerably small. It is clear from the above explanation that if the change in the high frequency voltage e2 due to the capacitance component Cx can be ignored, the value of the high frequency voltage e2 is proportional to the equivalent conductance including the conductance component Qx of the second tuner 4. be. For this reason,
Lower the effective Q so that it is approximately 10% or less compared to the equivalent conductance value obtained by converting the conductance component Gx to a value parallel to the tuning capacitance, or the equivalent parallel conductance of the coil 401, and further select the location of the branch point appropriately. For example, a change in the high frequency voltage e2 due to the conductance component Gx is proportional to the value of the conductance component Gx.

The high frequency voltages eI and e2 obtained as described above are detected by linear transverse wave detectors 6 and 7, respectively, and their outputs are applied to a differential amplifier 8. The output of the differential amplifier 8 is proportional to the conductance GX of the stratum corneum, and its value can be directly displayed on the indicator 9.

FIG. 3 shows an example of a circuit configuration diagram of an embodiment of the skin surface stratum corneum conductance measuring device shown in FIG. 1 according to the present invention. In FIG. 3, the crystal oscillator 1 includes a crystal oscillator 101 that does not use a constant temperature chamber, a transistor 107,
It consists of a plurality of passive elements. The buffer amplifier 2 includes a transistor 210, input coupling coils 201 and 202,
It consists of a plurality of passive elements. The first tuner 3 includes coils 305 and 306 for heavy electric power switching, and a variable capacitance element 301.
, a fixed capacitance element 302, and resistors 303 and 304. The second tuner 4 includes a coil to1 having an intermediate tap, capacitive elements 402 to 404, and a resistor 405.
It consists of. The measurement electrode section 5 is connected to the center tap f of the coil 401 built in the second tuner 4. The first linear detector 6 is a field effect transistor 60
2 and.

consists of a capacitive element 603 and a resistor 604].

The second linear detector 7 also has the same configuration as the first linear detector 6, and includes a field effect transistor 702.

It consists of a capacitive element 703 and a resistor 7'04.

The differential amplifier 8 includes an integrated circuit 808 for differential amplification.

It consists of a plurality of passive elements. The indicator 9 indicates a DC voltage proportional to the value of the conductance to be measured Gx, and must be calibrated in advance so that the conductance value can be read.

Figure 4 is 1. FIG. 6 is a diagram showing an example of the input/output characteristics of the second linear detector 6.7. In FIG. 4, high frequency input voltage e1. Alternatively, the DC output voltage has a proportional relationship with e2. 1st. and a second linear detector 6.7
Since it uses field effect transistors 602 and 702, it has high impedance input characteristics. For this reason, 1. and the Q of the tuning circuit of the second tuner 3, 4
The effect on the characteristics is much smaller than that of conventional configurations using npn) transistors.

On the other hand, FIG. 5 is a diagram showing an example of the relationship between the reading of the output voltage of the indicator 9 and the conductance to be measured Gx.

In FIG. 5, a curve 10o3 is a curve showing actually measured values, and a curve 1004 is a curve showing measured values (theoretical values).

As explained above, according to the present invention, the measurement frequency is precisely and stably set using a crystal oscillator, and a buffer amplifier that loosely couples the output of the crystal oscillator to the crystal oscillator provides heavy electrical tuning characteristics. Good heavy electrical tuning characteristics are achieved by adding the first and second tuners to the first and second tuners, which change the tuning curve depending on the value of the conductance to be measured, and this change is applied to the high-impedance tuner. By detecting with the first and second linear detectors and differentially amplifying the difference between the outputs of the rain detectors, there is an effect that the skin surface stratum corneum conductance can be easily and accurately measured.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a block configuration of an embodiment of the skin surface stratum corneum conductance measuring device according to the present invention. FIG. 2 is a diagram showing a tuning curve for conductance measurement in FIG. 1. FIG. 3 is a diagram illustrating an example of the configuration of the conductance measuring device 6 shown in FIG. 1. FIG. 4 is a diagram showing an example of the detection characteristics of the linear detector used in the conductance measuring instrument shown in FIG. 1. FIG. 5 is a diagram showing an example of the relationship between the indication of the indicator and the conductance value in the conductance measuring instrument shown in FIG. 1. 1...Crystal oscillator 2...Buffer amplifier 3
．． 4... Tuner 5... Measuring electrode section 6.
7...Linear amplifier 8...Differential amplifier 9...
・Indicator 23. ．． 2.4...Signal line patent applicant IB Niss Co., Ltd. Agent Patent attorney Hisashi Inoro

Claims (1)

[Claims] a crystal oscillator for generating a high frequency voltage; a buffer amplifier for inputting and amplifying the high frequency voltage by loosely coupling the crystal oscillator through a coupling element; a first tuner for providing heavy electrical tuning characteristics by tuning to the output of the first tuner, and a second tuner for providing heavy electrical characteristics by tuning to the output of the first tuner, which includes a coil having an intermediate tap for external output; a tuner; a measurement electrode portion connected to the intermediate tap and having a ring shape for detecting the conductance of the stratum corneum on the skin surface to be measured;
a first linear detector for detecting the output voltage of the buffer amplifier; a second linear detector for detecting the output voltage of the second tuner; and the first and second linear detectors. a differential amplifier for comparing the output voltages of the instruments and generating an output voltage proportional to the difference voltage; and an indicator for reading the output voltage of the differential amplifier and outputting the conductance of the skin surface stratum corneum to be measured. 1. A conductance measuring device for the stratum corneum on the skin surface, comprising: