JPH0230253B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to the structure and manufacturing method of a needle electrode used in an electromyograph for measuring myoelectric potential of a living body.

(Prior art) Measuring the potential difference between two points on a muscle fiber, or measuring the potential difference between one point and zero potential,
Means for detecting muscle fiber abnormalities are widely used. For this measurement, a detection electrode placed at the area to be measured and a reference electrode that detects the ground or average potential of muscle fibers over a wide range are installed, and these electrodes are connected to an electromyograph to detect changes in potential difference over time. A common method is to measure These electrodes include a dish-shaped surface electrode that is used to detect muscle activity in a wide range of superficial muscles, and a dish-shaped surface electrode that is used to derive myoelectric potential in a narrower range than the surface electrode, and that is used to detect muscle activity in one limited muscle or slightly deeper layer. There is a needle electrode that is used when testing for muscle. The structure of this needle electrode includes a detection electrode with the exposed tip of a metal wire whose surface is coated with insulation, a monopolar needle electrode using a copper plate, etc. as a reference electrode, and a hypodermic injection needle. A metal wire coated with insulation is enclosed in a metal tube,
A concentric needle electrode is known in which the metal wire is used as a detection electrode and the metal tube is used as a reference electrode. In addition, there is also one in which two metal wire detection electrodes are enclosed in the metal tube. The present invention relates to the above concentric needle electrode.

Among these concentric needle electrodes, there is one in which a detection electrode is made to protrude from the circumferential surface of the metal tube, making it easier to measure the potential at a shallow portion from the epidermis of the muscle fiber. In this case, a hole is formed on the circumferential surface of the metal tube by machining, etc., and a metal wire that becomes the detection electrode is inserted into the hole. After fixing to the inner diameter part of the metal tube, the metal wire of the part exposed from the hole is cut and polished so that it is flush with the outer peripheral surface of the metal tube. However, in this case, it is not only difficult to fix the metal wire in the center of the hole, but also burrs are left on the inner diameter end surface of the hole when forming the hole in the peripheral wall of the metal tube, which causes friction when inserting the metal wire. This caused the problem that the insulating coating formed on the outer periphery of the metal wire peeled off, causing electrical contact between the metal wire and the metal tube, making measurement impossible.

(Problems to be Solved by the Invention) The present invention solves the problem of conventional concentric needle electrodes by forming a hole in the peripheral wall of a metal tube that serves as a reference electrode to expose a metal wire that serves as a detection electrode. This technology solves the problem that sometimes the insulation coating of the metal wire peels off when the metal wire is inserted due to burrs generated on the inner diameter end surface of the hole, resulting in poor insulation between the metal tube and the metal wire. It is an object of the present invention to provide a needle electrode for an electromyograph and a method for manufacturing the same that can prevent the occurrence of poor insulation between the electrode and a reference electrode.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention inserts a metal wire whose periphery is insulated into a metal tube, and a part of the metal wire is inserted into the metal pipe. In a needle electrode for electromyography that is exposed from a part of a metal tube, at least one through hole penetrating the tube wall is formed in a part of the circumferential surface of the metal tube, and one end of the metal wire has a tubular shape. The tubular insulating member is inserted into the insulating member, and the tubular insulating member is fitted into the through hole, and the end face of the one end side of the metal wire and the outer end face of the tubular insulating member fitted into the through hole are connected to the metal wire. The needle electrode for electromyograph is constructed so as to be on the same plane as the outer peripheral surface of the tube.

In addition, as a manufacturing method of this needle electrode, a through hole is formed in a part of the peripheral surface of the metal tube, and a metal wire whose peripheral surface is coated with insulation is passed through the through hole to the inner diameter of the metal tube. After inserting the metal wire into the metal wire and making it protrude from one end of the metal tube, inserting a tubular insulating member into the metal wire exposed from the through hole, fitting the insulating member into the through hole, and then An insulating resin is injected into the metal tube to fix the metal wire and the insulating member to the metal tube, and the end surfaces of the metal wires and the insulating member on the insertion side into the through hole are attached to the outer periphery of the metal tube. It is cut and polished so that it is flush with the surface.

(Function) According to the above structure and manufacturing method, it is possible to form a through hole with a relatively large diameter, so when inserting a metal wire, it is possible to prevent the insulation coating of the metal wire from peeling off due to burrs in the through hole. . Furthermore, since a tubular insulating member is interposed at the contact portion between the metal wire and the metal tube, it is possible to prevent insulation failure from occurring during use.

(Example) Hereinafter, an example of a needle electrode for an electromyograph and a method for manufacturing the same according to the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show the structure of an embodiment of the present invention. A diameter of approximately
A 100 μm through hole 1a is formed obliquely with respect to the radial direction, and this through hole 1a has an outer diameter of approximately
A tubular insulating member 2 made of glass or the like with a diameter of 100 μm and an inner diameter of approximately 40 μm is fitted. A metal wire 3 having an outer diameter of about 25 μm and serving as a detection electrode is inserted into the inner diameter of the insulating member 2 and is made of gold or the like and whose surface is insulated with epoxy resin or the like. One end of the metal wire 3 inserted into the metal tube 1 is inserted into the metal tube 1 along the slope of the through hole 1a.
It is drawn out from one end of the body, and is connected to one of a pair of grids of an electromyograph (not shown). The other grid of the electromyograph is connected to the metal tube 1 by a conductor 4. An insulating epoxy resin or the like is sealed inside the metal tube 1 to fix the metal wire 3 and the insulating member 2.

Next, a method of manufacturing the electromyograph needle electrode according to this embodiment will be explained with reference to FIG. A needle-shaped metal tube 1 made of stainless steel or the like has a diameter of approximately
A 100 μm through hole 1a is formed in the wall of the metal tube 1 at an angle in the axial direction by means such as machining or electrical discharge machining. Next, as shown in b, a metal wire 3 made of gold or the like and having a diameter of about 25 μm and whose outer periphery is insulated with epoxy resin or the like is inserted into the through hole 1a, and is passed along the slope of the through hole 1a to one side of the metal tube 1. end face 1b of
Pull out a predetermined length from the metal wire, and attach an inner diameter of about 40 μm, an outer diameter of about 100 μm, and a length of about 0.3 mm to one end of the metal wire.
A tubular insulating member 2 made of glass or the like is inserted from the direction of the arrow and fitted into the through hole 1a. Next, as shown in c, the metal wire 3 drawn out from the insulating member 2 is wound around the outer circumference of the metal tube 1.
is held so that it does not shift relative to the metal tube 1.
Then, an insulating member 5 such as epoxy resin is injected into the metal tube 1 and dried and solidified to fix the metal wire 3 and the insulating member 2 to the metal tube 1. Finally, as shown in d, the metal wire 3 and insulating member 2 protruding from the through hole 1a of the metal tube 1 are cut and polished so that they are flush with the outer peripheral surface of the metal tube 1.

According to this embodiment, since the metal wire 3 is inserted through the through hole 1a formed in the metal tube 1 and having a relatively large inner diameter, the insulation coating of the metal wire 3 is not peeled off due to burrs remaining in the through hole 1a. can be prevented. Further, even after the metal wire 3 is fixed to the metal tube 1, since the insulating member 2 is interposed at the contact portion, no electrical continuity occurs between them.

In the embodiment described above, one through hole 1 is provided in the metal tube 1.
A has been described for the case where a plurality of through holes 1a are formed at a constant pitch as shown in FIG. A similar effect can be obtained if a plurality of tubular insulating members 2 are arranged in a line, fitted and fixed with an insulating member such as epoxy resin. In this case, one needle electrode can selectively detect the potentials of muscle fibers at multiple locations. Further, the dimensions of each part of the through hole 1a and the insulating member 2 are not limited to the dimensions shown in this embodiment.

[Effects of the Invention] As described above, according to the present invention, a through hole is formed in a metal tube that serves as a reference electrode of an electromyograph needle electrode, and a through hole is inserted through a tubular insulating member to serve as a detection electrode. Since the metal wire is held, it is possible to prevent the insulation coating of the metal wire from peeling off due to burrs in the through hole during manufacturing, and it is also possible to prevent insulation defects between the metal pipe and the metal wire after completion. .

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figures are a sectional view taken along the line AA in FIG. 1, FIG. 3 is a sectional view showing the manufacturing method of this embodiment, and FIG. 4 is a perspective view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Metal tube, 1a... Through hole, 2... Insulating member, 3
...Metal wire, 5...Resin.

Claims (1)

[Scope of Claims] 1. A needle electrode for an electromyograph in which a metal wire whose peripheral surface is coated with insulation is inserted into a metal tube, and a portion of the metal wire is exposed from a portion of the metal tube, At least one tube penetrating the tube wall on a part of the circumferential surface of the metal tube.
through holes are formed, one end of the metal wire is inserted into a tubular insulating member, the tubular insulating member is fitted into the through hole, and the end surface of the one end side of the metal wire and the through hole are fitted. A needle electrode for an electromyograph, characterized in that an outer end surface of the tubular insulating member passed through is on the same plane as an outer circumferential surface of the metal tube. 2. A through hole is a long hole drilled in the axial direction of a metal tube, and multiple metal wires whose circumferential surfaces are insulated are inserted into this long hole through a tubular insulating member. A needle electrode for electromyography according to claim 1. 3. Forming at least one through hole penetrating the tube wall in a part of the circumferential surface of the metal tube, and inserting a metal wire whose circumferential surface is insulated through the through hole into the inner diameter part of the metal tube. After the metal tube is made to protrude from one end, a tubular insulating member is inserted into each of the metal wires exposed from the through hole, the insulating member is fitted into the through hole, and then the insulating material is The metal wire and the insulating member are fixed to the metal tube by injecting a resin into the metal tube, and the end surfaces of the metal wire and the insulating member on the insertion side into the through hole are aligned with the outer circumferential surface of the metal tube. A method for manufacturing a needle electrode for an electromyograph, characterized by cutting and polishing so that they are on the same surface. 4. A patent characterized in that the through hole is formed in the shape of a long hole parallel to the axial direction of the metal tube, and a plurality of metal wires whose peripheral surfaces are coated with insulation are respectively inserted into the long hole into the inner diameter part of the metal tube. A method for manufacturing a needle electrode for electromyography according to claim 3. 5. The method according to claim 3 or 4, characterized in that the metal wire protruding from one end of the metal tube is wound and held around the outer periphery of the metal tube until the metal wire is fixed with resin. A method for manufacturing needle electrodes for electromyography.