JPS61128942A - Skin impedance measuring circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a skin impedance measuring circuit used for acupuncture point exploration.

(B) Conventional Technology Conventionally, as a method for exploring acupuncture points, there is an electrical resistance method that measures the skin resistance (impedance) when electricity is applied. In this electrical resistance method, a pair of metal electrodes, so-called dry electrodes, are brought into contact with the skin without using an electrolyte, and a DC voltage is applied.The skin impedance is small at acupuncture points, that is, Since the current applied is large, acupuncture points are explored by measuring skin impedance.

In this conventional skin impedance measurement, one of the pair of electrodes is held, for example, in the hand and is brought into contact with the skin over a relatively large area (this electrode is called an indifferent electrode), and the other is a relatively small electrode in the shape of a needle, for example. The electrode was brought into contact with the skin over a certain area, that is, point-contacted (this electrode is called a relative electrode), and a DC voltage of positive polarity was applied to the interstitial electrode and negative polarity to the indifferent electrode.

(c) Problems to be solved by the invention As mentioned above, by moving the interest electrode over the skin of a living body,
Acupuncture points are discovered by searching for points where skin impedance is small, that is, points where current is large, but in reality,
There are also points other than acupuncture points where the skin impedance is small, and this has caused a problem of erroneous detection of acupuncture points. In particular, acupuncture points are difficult to explore, so the electrode is often moved slowly, which means that a voltage is applied to one point in one direction, which causes skin breakdown and increases the amount of current applied.

In view of the above, an object of the present invention is to provide a skin impedance measuring circuit that can accurately explore acupuncture points while minimizing skin breakdown.

(d) Means for Solving Problems and 4″P In the skin impedance measurement circuit of the present invention, the negative electrode side of the direct current voltage of the electrode is applied. a first electrode that contacts the skin, a second electrode that makes point contact with the skin in a micro area smaller than the area of the first electrode, a current limiting resistor, the first electrode, and the second electrode. and a current-limiting resistor, and a current-carrying circuit for energizing the skin; a first electrode is connected to the positive side of the current-carrying circuit;
It is comprised of a DC voltage source that provides a voltage with a polarity such that the second electrode is on the negative side, and an output means that corresponds to the current flowing through the current-carrying circuit.

When electricity is applied to the skin using this skin impedance measurement circuit, it is possible to detect points other than acupuncture points for a predetermined period of time (
Although the skin breakdown current does not flow for several seconds, after a predetermined time period, the breakdown current flows like an avalanche. Therefore, the acupuncture point exploration is performed while moving to the next energized point within the above-mentioned time.

(E) Examples The present invention will be explained in more detail with reference to Examples below.

FIG. 1 is a skin impedance measurement circuit diagram showing one embodiment of the present invention. In the figure, the DC voltage source 1 is
The + side of the DC voltage e is connected to the indifferent electrode (first electrode) 2, while one side of the DC voltage e is connected to the indifferent electrode (second electrode) 3 via a protective resistor Rp for limiting the upper limit of the current. It is connected to the.

Further, both ends of the protective resistor Rp are connected to an amplifier 4 in order to derive a voltage according to the current flowing through the protective resistor Rp. Amplifier 4 amplifies the voltage and outputs it from terminal 5, causing a meter (not shown) connected to terminal 5 to swing.

The indifferent electrode 2 is formed in the shape of a rod, and the indifferent electrode 3 is formed in the shape of a needle. When energizing, the indifferent electrode 2 is held in the person's hand, for example, and the tip of the indifferent electrode 3 is placed on the skin surface. bring into contact. Therefore, the indifferent electrode 2 is in contact with the skin over a relatively large area, and the indifferent electrode 3 is in contact with the skin in a much smaller area than the indifferent electrode 2.

As mentioned above, when the indifferent electrode 2 is held in the hand, the indifferent electrode 3 is brought into contact with the skin surface, and the DC voltage source 1 is turned on, the voltage ■ is applied between the indifferent electrode 2 and the indifferent electrode 3, and the indifferent electrode 3 is brought into contact with the skin surface. A current flows from the electrode 2 to the electrode 3 via the skin. In other words, the indifferent electrode 2
, the electrical electrode 3 and the protective resistor R1) are connected to the energizing circuit 6.
A current I according to the skin impedance flows through the skin. When the skin impedance is large, the current ■ is small, and therefore the voltage obtained across the protective resistor Rp is also small.
The output derived from this is also small. Conversely, when the skin impedance is small, the current I is large, and the voltage across the protective resistor Rp,
The output output from terminal 5 also becomes large.

When using this embodiment circuit to explore acupuncture points, it is sufficient to move the interstitial electrode 3 to various locations on the skin surface to find points where the skin impedance is small.

In this case, if electricity is maintained at the same point on the skin, the skin will break down, the skin impedance will become small, and even a normal point will be mistaken for an acupuncture point.

Therefore, when the relationship between the current application time t (seconds) and the current application current (μA) at various points on the skin was determined using this example circuit, the characteristics shown in FIG. 2 were obtained. In this characteristic diagram, i represents the lip and the heart, which is a typical breakdown characteristic in which there is almost no current increase period and then the breakdown occurs suddenly. ii is the case of the palm; conversely, destruction occurs after a period of increasing current. iii is the 9th side of the foot, which is characteristically an intermediate case between the above i and ii. IV is an example of damage after the stratum corneum was peeled off several dozen times with cellophane tape on the forearm.

As far as these characteristics are concerned, there are considerable variations depending on the location, but in all cases there is a certain amount of time (several seconds) or more from the start of energization until the skin breaks down. Therefore, by moving the energizing point within a few seconds, exploration can be continued without causing skin damage.

On the other hand, Figure 4 shows the relationship between the energization time t (seconds) and the energization current I (μA) in a conventional circuit, that is, when applying a DC voltage with the separator electrode as the positive electrode. Types iii and iv are those in which the related electrode is a plate. According to this, an increase in current occurs from the time when the current application is started, indicating that skin destruction has already progressed.

Furthermore, in the case of the above-mentioned example circuit, that is, the case where the related electrode is of negative polarity, and the case of the conventional circuit, that is, that is, the case that the related electrode is made of positive polarity, a DC voltage is applied to the skin from the related electrode and the indifferent electrode, respectively. FIG. 3 shows a characteristic curve obtained statistically from the relationship between the applied voltage and the time at which skin breakdown occurs. In the figure, a is a conventional characteristic curve, and b is a characteristic curve of the embodiment circuit.

These characteristic curves were obtained by conducting a destructive test on the forearm in winter with a protective resistance Rp of 100KΩ, and a voltage of 7.5.10.15.
．． 25. Measurements were made 10 times for each voltage at 6 levels of 35.45V, and the breakdown time for each measurement was 1. The voltages are determined and the average value of the breakdown time t1 for each voltage is plotted. As is clear from these characteristic curves, if the applied voltage is the same value, the skin of the circuit of this embodiment does not break down for a longer period of time than the conventional circuit.

According to the characteristic curve, for example, if the applied voltage is 25 V and the current application time is 4 seconds or less, measurements can be made with almost no destruction.

In the circuit of the above embodiment, if the applied voltage V is set within the range of 10 to 30 V, the circuit is sufficiently practical, with almost no destruction occurring after a current application time of about 1 (second).

In the above embodiments, needle-shaped electrodes are used as the related electrodes, and rod-shaped electrodes are used as the indifferent electrodes, but these may have other appropriate shapes.

(f) Effects of the Invention According to the skin impedance measuring circuit of the present invention, since the negative electrode side of the DC voltage is applied to the related electrode (second electrode),
The predetermined time (several seconds) at the start of energization is unlikely to cause skin breakdown, and therefore, for example, when performing acupuncture point exploration, it is possible to reduce the possibility of erroneously determining points other than acupuncture points as acupuncture points, allowing for highly accurate acupuncture point exploration. It can be performed.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a skin impedance measuring circuit showing one embodiment of the present invention, Fig. 2 is a characteristic diagram showing the relationship between the energization time and the energization current measured using the same circuit, and Fig. 3 is a
FIG. 4 is a characteristic diagram showing the relationship between the applied voltage and the breakdown time in the same embodiment circuit and the conventional circuit. FIG. 4 is a characteristic diagram showing the relationship between the conduction time and the conduction current in the conventional circuit. 1: DC voltage source, 2: Indifferent electrode, 32-way electrode, 4: Amplifier, 6: Current-carrying circuit, Rp: Protection resistor. Figure 1 Figure 2

Claims (1)

[Claims] (1) a first electrode that contacts the skin over a relatively large area, a second electrode that makes point contact with the skin over a small area smaller than the area of the first electrode, and a current limiting resistor; Said first
an energizing circuit for energizing the skin by connecting the electrode, the second electrode, and the current limiting resistor;
A skin impedance measuring circuit comprising: a DC voltage source that provides a voltage with a polarity such that the second electrode is on the positive side and the second electrode is on the negative side; and an output means that derives an output according to the current flowing through the current-carrying circuit.