JPH03228738A - Living body potential measuring electrode - Google Patents

Abstract

PURPOSE:To carry out the stable measurement which is hardly influenced by the contact resistance and cables by constituting, integrally at least as one body, an electrode part for detecting the living body potential in close contact with a living body and an impedance conversion circuit in which the living body potential detected by the electrode part is converted into the low impedance and outputted. CONSTITUTION:A title living body potential measuring electrode is constituted of an electrode plate 11 for detecting the living body potential in contact with a living body, casing 12 which is formed so as to cover the back surface of the electrode plate 11, impedance converter 13 accommodated in the casing 12, and an output cable 14 for connecting the output of the impedance converter 13 and the input of a measuring device. The living body potential detected by the electrode plate 11 is inputted into the impedance converter 13 through an input cable 15, and the impedance converter 13 outputs the living body potential which is received with high impedance to the measuring device with low impedance through the output cable 14. Accordingly, because of the direct vicinity of a measurement point, the input impedance of the impedance converter can be set high, and since the measuring decice can be connected with low impedance, stable measurement can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a biopotential measuring electrode used for measuring biopotential.

(Conventional technology) Electrical signals called biopotentials such as myoelectricity, electrocardiography, and brain waves exist in living organisms including the human body, and by measuring these biopotentials, the state of biological activity can be electrically determined. be able to.

To measure this biopotential, biopotential measurement electrodes (hereinafter referred to as electrodes) are placed at measuring points on the living body to detect the biopotential.
or the biopotential detected by this electrode.
It is input to the ll-determiner.

By the way, when considering the influence of the contact resistance between the measuring point of the living body and the electrode on the measured value, the higher the input impedance of the measuring instrument, the less it is affected by the contact resistance. For example, when the input impedance is as low as 50 OKΩ or less, the influence of contact resistance between the electrode and the living body is large, and stable and accurate measurement cannot be expected.

On the other hand, when the input impedance of the measuring device is high, for example, 10XΩ or more, the influence of the contact resistance between the electrode and the living body on the measured value is reduced, but inductive noise is likely to be mixed in from the cable connecting the electrode and the measuring device. Furthermore, changes in stray capacitance between the cable and the living body due to cable sway etc. also affect the measured values. Therefore, when the living body is in motion, the state becomes so unstable that the baseline indicating the zero state of the biopotential jumps out of the measurement range.

Therefore, in the past, the input impedance of the measuring device was set to about IMΩ to moderate the above-mentioned influence, and electrode paste was used to improve the contact resistance with the living body when attaching the electrodes.

However, with an input impedance on the order of IMΩ, the influence of contact resistance cannot be ignored, so special techniques are required for how to apply electrode paste and how to fix electrodes in order to obtain the best conditions. Ta. In addition, due to the influence of stray capacitance, it was impossible to measure when the body was moving vigorously, such as when running at full speed.

(Problem to be solved by the invention) As mentioned above, in the past, the biopotential detected by the biopotential measuring electrode was input directly to the measuring device, which was not affected by various external factors, but stable measurement was possible. The present invention was made to address these issues, and provides a biopotential measurement electrode that can perform stable measurements with little influence of contact resistance or cables. .

[Configuration of the Invention (Means for Solving the Problem) The present invention includes an electrode part that is brought into close contact with a living body to detect a biopotential, and a biopotential that is detected by the electrode part and is output after being converted to a low impedance. The impedance conversion circuit is configured at least integrally with the impedance conversion circuit.

(Function) In the present invention, a biopotential measuring electrode and an electronic circuit device such as an impedance converter that receives detected biopotential at high impedance and outputs it at low impedance are integrally configured.

Therefore, since the bioelectrical potential can be received at high impedance, the influence of contact resistance with the living body is reduced, and attachment to the living body is facilitated.

Furthermore, since the biopotential measuring electrode and the measuring device can be connected with low impedance, the influence of the cable for connecting to the measuring device is reduced, allowing stable biopotential measurement.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the configuration of a biopotential measuring electrode according to an embodiment of the present invention.

As shown in the figure, this biopotential measurement electrode 10 includes an electrode plate 11 that detects biopotential by contacting a living body, and an electrode plate 1
1, and an impedance converter 1 housed in the casing 12.
3 and an output cable 14 that connects the output of the impedance converter 13 and the input of a measuring device (not shown).

The biopotential detected by the electrode plate 11 is input to the impedance converter 13 via the input cable 15. The impedance converter 13 outputs, for example, the biopotential received at high impedance to the measuring instrument via the output cable 14 at low impedance.

In this way, since it is close to the measuring point, the input impedance of the impedance converter can be set high, and since it can be connected to the measuring device with low impedance, stable measurements can be performed.

Moreover, the appearance of this bioelectrometer 71111 electrode 10 is the second
As shown in the perspective view of Figure (a) and the side view of Figure 2(b), there is no difference from the conventional bioelectrometer/III electrode, but the electrode plate 11 is made smaller because the influence of contact resistance is reduced. Therefore, the overall size of the biopotential measurement electrode 10 can be reduced.

Note that the impedance converter does not need to have an amplification factor, but if it has an amplification factor, it will be more advantageous against noise and the like.

Next, other embodiments will be described.

Normally, biopotential measurement is performed by inputting biopotentials detected by two biopotential measurement electrodes attached to a measurement point into one differential amplifier. Therefore, as shown in FIG. 3, a differential amplifier 21 is built into one bioelectrometer #1 electrode 20a, and each electrode plate 22 is connected to this differential amplifier 21. The biopotential amplified by the differential amplifier 21 is output to the measuring instrument with low impedance.

FIG. 4 shows the appearance of the biopotential measuring electrode of this example.

Therefore, since the number of cables connected to the measuring device is reduced, mobility with the electrode attached is improved.

In addition, in this embodiment, the biopotential measuring electrode 20b does not have an electronic circuit built-in, or the biopotential measuring electrode 20b
It is also possible to incorporate an electronic circuit device such as an impedance converter.

[Effects of the Invention] In the present invention, since the biopotential measuring electrode and the electronic circuit device are integrated, the input impedance of the electronic circuit device can be increased to about 100 MΩ, and the distance between the electrode and the measuring device is also low. It is possible to connect by impedance.

Therefore, the influence of contact resistance with the living body is reduced, making it easier to attach it to the living body.Furthermore, the cable for connecting to the measuring instrument is less susceptible to the influence, so it can be used even when the living body is doing intense exercise. It is also possible to measure stable biopotentials.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a biopotential measurement electrode according to an embodiment of the present invention;
FIG. 2(a) is a perspective view of the biopotential measuring electrode of FIG. 1, FIG. 2(b) is a side view of the same, and FIG. 3 illustrates the configuration of the biopotential measuring electrode of another embodiment of the present invention. FIG. 4 is a diagram showing the appearance of the bioelectrometer 71111 electrode of FIG. 3. 10... Biopotential measurement electrode, 11... Electrode plate, 12...
・Casing, 13... Impedance converter, 14
... Output cable, 20a, 20b... Biopotential measurement electrode, 21... Differential amplifier, 22. Electrode plate.

Claims (1)

[Claims] (1) An electrode part that is brought into close contact with a living body to detect a biological potential;
A biopotential measurement electrode characterized in that it is configured at least integrally with an impedance conversion circuit that converts the biopotential detected by the electrode portion into a low impedance and outputs the low impedance.