JPS60158834A - Dry muscle operation signal detection apparatus - 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 [Field of Industrial Application] The present invention relates to a dry muscle movement signal detection device used, for example, in an electrocardiograph.

[Prior Art] Conventionally, many electrodes have been used to detect muscle movement signals. These can be roughly classified into three types. The first type consists of a simple metal plate, which is contacted to the skin surface via a conductive paste or gel. The metal plate must have excellent conductivity, and stainless steel or nickel is generally used. In this type of electrode, polar voltages result from chemical imbalances at the metal-to-electrolyte contact and the electrolyte-to-skin contact. In other words, this polar voltage can cause changes in body temperature, sweating,
It changes due to changes in the electrolyte concentration of the base or gel, relative displacement between the metal and the skin, etc., and the current changes as well.

In order to stabilize such electrolyte voltage, muscle movement signal detection devices having various configurations have been proposed. The second type of electrode is the widely used silver/silver chloride electrode.

This electrode is also brought into contact with the skin via a conductive paste or eyeglass. This electrode has the advantage of reduced electrolyte voltage and is more stable. Both types of electrodes described above are fully functional once the skin lipids have been wiped away with a solvent and the dead skin removed by abrasion. However, pre-treatments such as ε reduce the impedance of the skin electrolyte interface.

A third type of electrode requires no prior treatment of the skin surface or a conductive medium. This electrode is resistively or capacitively coupled to the conductor to the skin. In the case of capacitively coupled electrodes, the electrode surface is coated with a thin dielectric material and the electrode acts as a capacitor. Although capacitor-coupled electrodes have the advantage of not requiring a conductive medium, they have fairly high inherent noise. Furthermore, this electrode has poor reliability for long-term use because the dielectric material changes sensitively due to perspiration or corrosion of the dielectric material.

[Problems to be Solved by the Invention] An object of the present invention is to provide an improved resistance-coupled dry muscle action signal detection device for detecting muscle action signals on the skin surface.

In order to achieve the above object, the present invention has a contact surface made of an electrical insulator that is in contact with the skin surface, and a ring-shaped conductor that surrounds the contact surface and is formed to be in contact with the skin surface. an electrode consisting of a grounding ring, a pair of contact pieces disposed on the contact surface with an interval of 8 to 12 mm, and a current detected by the pair of contact pieces below the skin surface; and an amplifier connected to the one contact piece and receiving a detection signal from the contact piece.

[Function j] The dry muscle movement signal detection device according to the present invention includes a contact surface 15 made of a non-conductive material that comes into contact with the skin surface, and this contact surface 15 is surrounded by an annular ground ring 16 made of a conductive material. , this ground ring 16 is also configured to come into contact with the sebum surface. A pair of contact pieces 12 and 13 as electrodes are arranged on the contact portion 15 with an interval of 8 to 12 mm. The pair of contact pieces 12 and 13 are connected to an amplifier 1B, whereby the detection signal is amplified.

When the ground ring 16 is brought into contact with the skin surface to scan the electrical signals generated by the muscles, the ground link 16
The skin surface surrounded by the ground ring 16 is grounded to a constant reference level, nullifying extraneous signals transmitted to the skin surface outside the ground ring 16. Therefore, disturbance of the required muscle movement signals and interference with signals generated from nearby muscles can be suppressed.

The distance between the pair of contact pieces 12 and 13 is determined by the frequency band of the filtering characteristics of the differential recording device. As a result, a pair of contact pieces 1
The interval of 2.13 is determined to fit a typical muscle movement signal detected by the electrodes. Furthermore, sufficient spacing is provided between the pair of contact pieces 12, 13 to prevent electrical short circuits between the contact pieces when used on perspiring skin surfaces; Between .13 and 1- is the electrode 41
It is said to be suitable for downsizing four-story buildings. Due to these conditions of the electrode, it is possible to apply Elt4G on the sebum surface without any other prior treatment such as conventional gel or paste.
signal can be detected.

[Embodiments of the Invention] The present invention will be explained based on embodiments. FIG. 1 shows a dry muscle movement 4'F=signal detection device 11 according to the present invention.

One armature of the contact piece 12 , 13 is held in a plug 14 with a flat contact surface 15 . The plug 14 is covered by a cylindrical ground ring 16. The upper end surface of the ground ring 16 forms a flat ground surface 17 that defines a predetermined skin area. The earth ring 16 is preferably made of titanium (
While made from a corrosion-resistant material such as ASTM 8348), the plug 14 is made of epoxy resin to retain the contact pieces 12, 13 and is filled inside the ground ring 16.

Corresponding to the required geometrical conditions, the contact piece 12.13
is projected from the ground plane 17 by at least Q, 5 mm.

Further, it projects from the contact surface 15 by at least 0°501 m from the contact surface 15. The amount of protrusion of the ground surface 17 from the contact surface 15 is at least 0.5n1111&. In addition, the width of the pair of contact pieces 12.13 (or 2 to 5 u+n+), and the interval between the pair of contact pieces 12.13 is 8 to 12 m.
It is assumed to be ll1.

While forming the plug 14, the contact pieces 12 and 13 are respectively soldered to the input terminals of the circuit that constitutes the amplifier 18 shown in FIG. Connecting pieces 12 and 13 to the amplifier 18
After connecting, these are the 7 foot ring 16 of the frame
The plug 14 is placed inside the earth ring 16, and then the plug 14 is molded by filling the inside of the earth ring 16 with epoxy resin. In this way, the dry muscle movement signal detection device 11 is completed.

The amplifier '18 receives the detection voltages Ea and Eb from the contact pieces 12 and 13, respectively, and receives the detection voltages Ea and Eb from the first ground width circuit 21, etc.
It is composed of a ground width circuit 22, a third ground width circuit 23, and the like. The first ground width circuit 21 includes a pair of differential amplifiers Δ1. A2
are connected to each other to form a -C configuration, and each output terminal is connected to a resistor R1,
R2, R3 and content 4 no 01. It is connected to each - input terminal via C2.

The first ground width circuit 21 has a gain (amplification factor) equal to (R3+2R1) and 'R3, and is in a common mode with a gain of O for the input signal voltage.

The second ground width circuit 22 includes a differential amplifier A3, and receives the differential output signal of the first ground width circuit 21 via resistors R4 and R5.

The output terminal of amplifier A3 is connected via a resistor 6 to one input terminal of amplifier 3, while the input terminal of amplifier A3 is connected via a resistor 7 to a conventional circuit. The second ground width circuit 22 has a gain equal to R6 and /R4.

The third ground width circuit 23 includes a buffer amplifier A4 that modifies the output signal of the amplifier A3, and the output terminal of the second ground width circuit 22 is connected to one input terminal of the amplifier Δ4 via a resistor R8. be done. The ten input terminals of the amplifier A4 are connected to an ordinary circuit, while the one input terminal of the amplifier A4 is connected to the output terminal of the amplifier A4 through a parallel circuit of a resistor R9 and a capacitor C3. Gain R9 by the third ground width circuit 23
/'R8 is obtained. ] Dendenzers C1, 02, and C31 are inserted into the feedback circuits of the first ground width circuit 21 and the third ground width circuit 23, and act as low-pass filters. Thus, the final output signal voltage of the amplifier 18 is EOut - (Eb - Ea) (R8+2R1)R
6・R9,,/R3・R4・R8>.

To explain a typical usage example of the dry muscle movement signal detection device '11 according to the present invention, the dry muscle movement signal detection device '11
1 has a contact surface 15 pressed against the skin surface covering a predetermined muscle. There is no need to apply paste, gel, etc. between the contact surface 15 and the skin surface.

Since the ground plane 17 and the contact pieces 12, 13 project outward, these elements are held firmly in contact with the skin surface and perform a unique electrical contact function. The contact pieces 12 and 13 detect EMG signals generated in the muscles below the skin surface, and the detected voltages Ea, l:b are amplified by an amplifier @18 consisting of a three-stage amplification circuit. The output signal of amplifier 18 is sent to the required equipment via cable 25. For example, the output signal is sent to an oscilloscope, or if it exceeds a certain threshold,
It can be sent to a threshold device where an audio output signal or an image output signal is generated.

The invention is susceptible to other modifications, as will be apparent from the above description. For example, in the embodiment described above, a circular 161-shaped ground ring is advantageous in manufacturing, but the shape of this ground ring may also be box-shaped.

[Effects of the Invention] (1) According to the present invention, the grounding ring 16 has an annular grounding surface 1 that is pushed onto the flat skin surface of the detection surface.
7, and a pair of contact pieces 12, 13 protrude upward by at least 0.5 mm from the ground surface 17. Even in such cases, it works to closely adhere to the skin surface to be detected. The contact surface 15 is substantially flat, and the annular ground surface 17 surrounding the contact surface '15 protrudes from the contact surface ]5 by at least Q, 5 mm.
The ground plane 17 makes good contact with the skin surface, and the area of skin surrounded by it is electrically shielded. Roughly speaking, the pair of contact pieces 12 and 13 have a width of at least 2 to 5 nm+m from the annular ground surface 17, and the ground ring 16 is approximately circular, so it is lightweight and compact for easy portability. can do.

(2) The ground ring 16 is configured as a hollow frame made of a conductive material, and surrounds the plug 14 made of a non-5MN material that partitions the contact surface 15, and this plug 14 also has a pair of contact pieces 12, 13. and the amplifier 18, the dry muscle movement signal detection device is constructed as a small, completely integrated unit.

(3) The amplifier device 18 includes a pair of first step difference initial layer width circuits 21
The detection signals of the pair of contact pieces 12 and 13 are applied to the input terminal of the 1st stage differential width circuit 2.
1 are connected to each other to generate a differential output (fi signal). This differential output signal is applied to the second stage differential amplifier circuit 22,
The output signal of the second stage differential amplifier circuit 22 is applied to the third stage output conversion buffer amplifier circuit 23. This circuit 41
The four components provide the required common mode radiation, amplification and frequency band of the output signal.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a dry muscle motion signal detection device according to the present invention, and FIG. 2 is an electrical circuit diagram of the dry muscle motion signal detection device shown in FIG. △1. A2. A3: Differential amplifier A4: Buffer amplifier 11; Dry muscle movement signal detection device 12゜13: Contact piece 14 Nibrag 15: Contact surface 16: j'-sling] 7: Earth surface 21: First ground width circuit 22: 2nd layer width circuit 23: 3rd layer width circuit 25: Cable patent applicant Libadi Mutual Insurance Company agent Patent attorney Toshio Yamamoto

Claims (4)

[Claims] (1) A contact surface made of an electrical insulator that comes into contact with the skin surface; a ground ring made of an annular conductor that surrounds the contact surface and is formed to be in contact with the skin surface; an electrode comprising a pair of contact pieces disposed on the contact surface; a current source located under the skin surface and detected by the pair of contact pieces; and an electrode connected to the pair of contact pieces and connected to the contact piece; A muscle movement signal detection device comprising: an amplification device that receives a detection signal from a contact piece. (2) The grounding ring has an annular grounding surface that comes into contact with the skin surface to define a predetermined grounded skin surface, and the pair of contact pieces protrudes from the grounding surface by at least Q, 5 inches. The range of the characteristic Th'Fg^ sought (
1) The dry muscle movement signal detection device according to item 1). (3) A plug made of an electrical insulator partitions the contact surface and holds the pair of contact pieces and the amplifier, and the ground ring takes the plug and is recessed in a hollow part made of the electrical insulator. The dry muscle movement signal detection device according to claim (1), which constitutes a frame. (4) A pair of differential foil one-installation amplifier circuits in which the amplifier device amplifies the detection voltages of the pair of contact pieces separately, and a difference in which the output signal of the first ground width circuit is used as an input signal. 1ilI second
The dry muscle movement signal detection device according to claim (1), comprising a ground width circuit and an output conversion buffer amplifier circuit that receives the output signal of the differential type dual amplifier circuit as an input signal. (5) The dry % type % according to claim (2), wherein the contact surface is substantially flat and the ground surface protrudes from the contact surface by at least Q, 5 mm.