JP2008054720A - Sheet-like bioelectrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet-like bioelectrode which is free from a possibility to damage nerves, is attached more easily than before, and hardly develops a poor electrical contact between nerves and electrodes. <P>SOLUTION: The bioelectrode 10 is equipped with a sheet-like insulating substrate 11, two sheet-like electrodes 12 which are fixed on the substrate and have flexibility, wire leads 13 connected to the electrodes 12, and a thread 14 connected to the substrate 11. Two electrodes 12 are arranged in parallel, and the nerve 15 is placed on two electrodes in a manner to cross electrodes 12 perpendicularly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet-like bioelectrode.

JP 2003-204946 A

  Conventionally, a method of inserting an electrode into a living body and electrically measuring nerves and the like of the living body is known. In this method, tissue around the nerve to be measured is peeled off in accordance with the size of the electrode, the electrode is connected to the nerve and embedded in the living body, and the minute potential difference or minute current of the nerve is measured.

  As a microelectrode used for such a measuring method, as shown in Patent Document 1, a cylindrical biological electrode having a slit, in which a cylindrical non-conductor and a cylindrical conductor are alternately stacked. Are known. In this bioelectrode, an electrode slit is opened, a nerve is inserted into the central hole from the slit, and the slit is closed to mount the nerve. Since this bioelectrode uses a synthetic resin having a flexible electrode material, particularly silicone rubber as a conductor, it is difficult to damage nerves. Further, since the nerve is attached to the cylindrical center hole, there is an advantage that it is difficult to come off.

  However, this cylindrical bioelectrode has the following problems. When performing this measurement method, the tissue around the nerve to be measured is peeled off in accordance with the size of the electrode, so in order to measure the sympathetic nerve of a small living body such as a rat or mouse, such a cylindrical biological electrode Then there is a problem that it is too big. Further, since the nerve is inserted into the cylindrical central hole, the measurement is likely to be performed while the nerve is pulled, and the nerve may be damaged. Furthermore, since the shape is cylindrical and the nerve is inserted from the slit, its attachment is difficult. And since the measurement site | part of a nerve is in a bioelectrode, the contact site | part of a nerve and its conductor cannot be seen, and a measurement tends to become unstable.

  On the other hand, it is also known to use a parafilm and a metal wire electrode as a biological electrode. In this bioelectrode, a parafilm is placed under the nerve from which the tissue has been peeled off, and a metal wire electrode is slid between the nerve and the parafilm to bring the nerve and the electrode into contact with each other. In other words, since this electrode has a simple structure and can be made compact, it can reliably measure in an acute experiment, etc., can be used regardless of its use location and situation, and can be easily installed. There is an advantage of being. Furthermore, since it is not bulky as an electrode, it is less likely to pull the nerve and less likely to damage the nerve. Moreover, since the contact site | part of an electrode and a nerve can be visually observed, the mounting | wearing can be performed reliably.

  However, even with such a bioelectrode, the metal wire is brought into direct contact with the nerve, which may damage the nerve. In addition, since only a metal wire is inserted into the living body as an electrode, there is a problem that the nerve and the electrode are easily detached during measurement, or poor contact is likely to occur.

  The present invention was created in view of the problems of conventional bioelectrodes using parafilm, maintains the advantages of conventional bioelectrodes, has a low risk of damaging nerves, is easier to attach, and nerves and electrodes An object of the present invention is to provide a sheet-like bioelectrode in which poor contact with the electrode hardly occurs.

  The sheet-like bioelectrode of the present invention is a bioelectrode that is embedded in a living body and electrically measures nerves and the like, and has a sheet-like insulating substrate and flexibility 2 fixed on the substrate. It consists of a sheet-like electrode and a lead wire connected to the electrode, and the two electrodes are arranged in parallel so that the nerve is arranged on the two electrodes so as to intersect the electrode perpendicularly. It is characterized by being lined up.

It is preferable that such a biological electrode has a groove for holding the two electrodes so that nerves are not displaced. Moreover, what was provided with the sheet-like insulating cover for providing on the nerve arrange | positioned on the said electrode is preferable.
On the other hand, two sheet-like bioelectrodes of the present invention may be used and stacked so as to sandwich the nerve.
In any of the bioelectrodes of the present invention, it is preferable that the insulating substrate and / or the insulating lid is provided with an operation thread. And what uses electroconductive silicone rubber as a material of an electrode is preferable.
Further, a thin metal conductor may be provided inside the electrode. Furthermore, a shape holding portion made of a shape memory material may be provided under the substrate.

  The sheet-like bioelectrode of the present invention comprises a sheet-like insulating substrate, two flexible sheet-like electrodes fixed on the substrate, and lead wires connected to the electrodes. The structure is simple and the installation is very easy. That is, the mounting operation can be performed only by changing the angle of the substrate laid under the nerve so as to intersect two electrodes arranged in parallel. Therefore, even if it is a very small electrode, the difficulty of the attachment work does not change so much. Further, since the electrode is fixed to the substrate, there is little possibility of contact failure or nerve disconnection due to electrode displacement after the nerve is attached to the electrode. Furthermore, since the electrode uses a flexible material, there is little risk of damaging the nerve. And since it is not bulky as a whole bioelectrode, it can be mounted without pulling the nerve. Since the contact site between the nerve and the electrode can be visually observed, the nerve can be securely attached.

  In such a biological electrode, when a groove for holding the nerve so as not to shift is formed on the two electrodes, the nerve can be mounted more reliably, and the displacement or disconnection after mounting can be prevented. Can be prevented. Further, when the sheet-like insulating lid is placed on the nerve placed on the electrode, the state can be fixed with the lid after visually observing the contact of the nerve with the electrode. Therefore, it is possible to prevent contact failure due to electrode displacement or disengagement after mounting.

  In addition, when two sheet-like bioelectrodes of the present invention are used and stacked so as to sandwich the nerve, it is possible to prevent displacement or detachment of the electrode after the nerve is mounted, as in the case of placing the lid. it can.

In any one of the bioelectrodes of the present invention, when an operating thread is provided on the insulating substrate and / or the insulating lid, an operation for attaching the bioelectrode in the living body, for example, the substrate under the nerve Insertion or opening / closing of the lid can be facilitated. This thread may be detached after the bioelectrode is attached.
When silicone rubber is used as the material of the electrode, the electrode can be made flexible, and nerves are hardly damaged.
When a thin metal conductor is provided inside the electrode, the conductor acts as a rib of the sheet-type electrode and is not easily deformed after being embedded in the living body. Moreover, when the shape holding part which consists of shape memory materials is provided under the said board | substrate, it can be made into a desired shape and can be maintained by giving energy, such as a heat | fever.

  Next, the bioelectrode of the present invention will be described with reference to the drawings. 1a, b and c are a perspective view, a front view and a side view showing one embodiment of the bioelectrode of the present invention, and FIGS. 2a and 2b are front views and other views showing another embodiment of the bioelectrode of the present invention. 3a, b, and c are side views showing still another embodiment of the bioelectrode of the present invention, and FIGS. 4a and 4b are perspective views showing still other embodiments of the bioelectrode of the present invention. FIG. 4c is a side view when FIG. 4b is bent, FIG. 5a is a perspective view showing another embodiment of the bioelectrode of the present invention, and FIG. 5c is a side view. It is a side view when bent and used.

  A bioelectrode 10 shown in FIGS. 1a to 1c is a sheet-like insulating substrate 11, two sheet-like electrodes 12 having flexibility to be fixed on the substrate, and two electrodes connected to the electrodes. Lead wire 13 and a thread 14 connected to the substrate 11.

  The insulating substrate 11 has a thickness of 0.05 to 0.3 mm, particularly 0.05 to 0.15 mm, and its size is arbitrarily determined depending on the object to be measured. When the thickness is larger than 0.3 mm, there is a risk of damaging the bulky nerve as a whole biological electrode. Examples of the material of the substrate 11 include rubbers such as non-conductive silicone rubber, or synthetic resin materials such as fluorine-based resin, polyurethane, and nylon elastomer. In particular, non-conductive silicone rubber is flexible and biocompatible. It is preferably used because of its good properties.

The electrode 12 has a thickness of 0.1 to 0.5 mm, particularly 0.2 to 0.4 mm. When the thickness is larger than 0.5 mm, the whole bioelectrode is bulky.
The electrodes 12 are fixed on the substrate 11 so as to be parallel to each other. The electrode 12 is fixed to the substrate 11 with an adhesive or the like.
For the electrode 12, a conductive polymer material having rubber-like elasticity such as conductive rubber is used. In particular, conductive silicone rubber is preferable because of its good biocompatibility.

  The lead wire 13 is connected to one end portion (upper end portion in the drawing) of the electrode 12. By embedding and connecting the lead wire 13 in a sheet-like electrode, the entire electrode can be thinned and the resistance in the electrode can be suppressed. This is because the distance from the connection point between the lead wire and the electrode to the nerve (measurement target) can be shortened. By shortening the distance, a sheet-like electrode made of a conductive resin (especially silicone) Resistance due to rubber) can be reduced. However, you may affix on an electrode by an adhesive agent, solder, pressure bonding, etc. As such a lead wire 13, metals such as platinum, gold, silver, copper, and stainless steel are used.

  The thread 14 is attached to a part of the bottom of the substrate 11 (the surface on which no electrode is provided) with an adhesive or the like. By sticking on the surface where the electrode is not provided in this way, there is no possibility that the electrode 12 is peeled off by operating the thread 14. Further, the thread 14 extends on the side opposite to the lead wire 13. Thereby, the direction of the substrate 11 can be manipulated while pulling the thread 14 and the lead wire 13.

  The biological electrode 10 configured in this manner preferably has a thickness of 0.2 to 1.0 mm, particularly 0.2 to 0.5 mm. Then, the biological electrode 10 is embedded in the living body as follows. First, the tissue around the nerve to be measured is removed according to the size of the electrode. Next, the biological electrode 10 is inserted under the nerve. At this time, as shown in FIG. 1a, the nerves 15 (imaginary lines) are arranged while adjusting the substrate 11 so as to intersect the two electrodes 12 vertically. Finally, a silicone gel is poured around the electrode to insulate the electrode from the periphery and fix the electrode and the nerve 15. Here, the yarn 14 of the substrate 11 may be cut before or after pouring the silicone gel.

  Since the bioelectrode 10 is fixed to the substrate, the attachment of the nerve 15 can be completed simply by operating the substrate 11 when the electrode is fixed in the living body, and the attachment is very simple. In addition, there is little risk of contact failure or nerve detachment due to displacement of the electrode 12 after the nerve 15 is attached to the electrode 12. Further, since the electrode 12 is a flexible sheet, it is difficult to damage the nerve 15. And since the contact site | part of the nerve 15 and the electrode 12 can be visually observed, the electrode 12 and the nerve 15 can be mounted | worn reliably and the stable measurement can be aimed at.

The biological electrode 20 shown in FIGS. 2a to 2b includes a groove 22 for holding the nerve to which the electrode 21 is attached so as not to shift. Other configurations are substantially the same as those of the bioelectrode 10 shown in FIG.
Since it is configured in this manner, the substrate 11 is operated so that the nerve 15 is inserted into the groove of the electrode 21 when the biological electrode 20 is inserted into the living body. Thereby, the shift | offset | difference of the nerve 15 can be prevented and a more stable measurement can be performed.

A biological electrode 30a shown in FIG. 3a is obtained by providing the biological electrode 10 shown in FIG. The lid 31 has a thickness of 0.05 to 0.3 mm, particularly 0.05 to 0.15 mm. The bioelectrode 30a has an overall thickness of 0.3 to 1.3 mm, particularly 0.3 to 0.6 mm.
The size and material of the insulating lid 31 are substantially the same as those of the substrate 11. Thereby, the electrode 11 can be covered with the substrate 11 and the lid 31. The lid 31 and the substrate 11 are connected to each other by an adhesive or the like at the end. In FIG. 3 a, the lid 31 and the substrate 11 are connected at the upper part in the drawing. This connecting portion corresponds to a connecting portion between the electrode 12 and the lead wire 13 in the substrate 11, and the connection between the electrode 12 and the lead wire 13 is reinforced by connecting the lid 31 and the substrate 11 at this portion. be able to. In addition, the contact pressure of the part to be measured of the living nerve can be made almost constant, and the measurement error is small. In other words, more stable measurement can be expected. However, the lid 31 may be separated from the substrate 11. When a transparent or translucent material is used for the lid, the contact state between the nerve and the electrode can be visually confirmed from above the lid.

  Since it is configured in this manner, the lid body 31 and the substrate 11 of the bioelectrode 30a are opened using the thread 14 and the thread 32 as shown by the imaginary line in FIG. 3a so that the substrate 11 is under the nerve. To place. And after adjusting the board | substrate 11 and arrange | positioning the biological electrode 30a so that a nerve may become perpendicular | vertical with respect to the electrode 12, the cover body 31 is covered on the board | substrate 11 so that a nerve and the electrode 12 may be covered. Thereafter, a silicone gel is poured to fix the biological electrode 30a. Here again, the yarn 14 and the yarn 32 may be cut off.

  A biological electrode 30b shown in FIG. 3b is obtained by providing the biological electrode 20 of FIG. 2 with an insulating lid 31 provided with a thread 32. Furthermore, the bioelectrode 30c shown in FIG. 3c is obtained by connecting two bioelectrodes 10 in FIG. 1 so that the electrodes 12 face each other. Since these are also embedded in the living body like the biological electrode 30a of FIG. 3a and attached to the nerve, the electrode and the contact part of the nerve can be covered with the lid and the substrate or the substrates, so that the measurement error is reduced, Measurement can be performed more stably.

  The biological electrode 40 shown in FIGS. 4 a and b includes a base material 41, an electrode 42 fixed on the base material, a conductor 43 fixed inside the electrode 42 so that a part protrudes from the substrate, A lead wire 44 connected to the conductor protrusion 43a and a thread 45 connected to the substrate 41 are provided. The conductor 43 is made of a highly conductive metal such as silver-plated copper, and has a thickness of 0.1 to 0.5 mm, particularly 0.2 to 0.4 mm. The thickness of the biological electrode 40 is 0.2 to 1.0 mm, particularly 0.2 to 0.5 mm. Since it is such a thickness, it does not become bulky. The biological electrode 40 is obtained by dividing the ten lead wires 13 of the biological electrode of FIG. 1 into a thin plate-like conductor 43 embedded in the electrode and a lead wire 44 connected to a measuring instrument or the like. Other configurations are substantially the same as those of the bioelectrode of FIG.

  The biological electrode 40 holds the shape of the state in which the metal shape holding force of the conductor 42 is bent by arranging the biological nerve on the biological electrode 40 and bending it as shown in FIG. 4C. By using the biological electrode 40 so as to sandwich the nerve in this way, the pressure applied to the entire nerve part sandwiched between the biological electrode 40 can be made constant, and the displacement of the electrode after mounting is prevented. be able to.

  Further, like the biological electrode 40a shown in FIGS. 5a and 5b, a shape holding portion 46 made of a shape memory material may be provided under the base 11 of the biological electrode 10 of FIG. 1 or the biological electrode 40 of FIG. 4a. When energy such as heat and current is applied to the shape holding portion 46, the shape holding portion 46 is designed to be deformed into a U-shape in advance, so that when the energy is applied to the biological electrode 40a, the biological electrode 40a wraps the nerve. It changes to such a shape (FIG. 5c), and the shape is maintained. In this case as well, the pressure applied to the entire nerve measurement site can be made constant as in the case of the biological electrode 40, and the mounting operation is easy.

  A base material 41 having a size of 2 × 2 mm and a thickness of 0.1 mm, a conductor 42 having a size of 4 × 0.5 mm and a thickness of 0.07 mm, and a size of 2 × 0.6 mm and a thickness Is a biological electrode 40 which is composed of an electrode 43 of 0.38 mm, omitting the lead wire and the thread, and is referred to as Example 1.

  The tester 50 is connected to the conductor 42 of the first embodiment, and a silver-plated copper wire 51 having a diameter of 0.2 mm is disposed on the electrode 43, and the silver-plated copper wire 51 as a whole on the biological electrode 43 is disposed thereon. The weight 52 is arranged so as to cover the surface. The weight of this weight and the resistance applied to both conductors were measured. The relationship is shown in Table 1.

  From this experiment, it can be seen that the electrode resistance changes depending on the contact pressure with the nerve. Therefore, it is preferable that the contact pressure between both electrodes and the nerve is the same.

1a, b, and c are a perspective view, a front view, and a side view showing an embodiment of a biological electrode of the present invention. 2a and 2b are a front view and a partial side view showing another embodiment of the bioelectrode of the present invention. 3a, 3b, and 3c are side views showing still other embodiments of the bioelectrode of the present invention. 4a and 4b are a perspective view and a side view showing still another embodiment of the bioelectrode of the present invention, respectively, and FIG. 4c is a side view when FIG. 5a and 5b are a perspective view and a side view, respectively, showing still another embodiment of the bioelectrode of the present invention, and FIG. 5c is a side view when FIG. 5b is folded and used. 6a and 6b are schematic diagrams of experiments for measuring the resistance of the bioelectrode of FIG. 4a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bioelectrode 11 Insulating substrate 12 Electrode 13 Lead wire 14 Thread 15 Nerve 20 Bioelectrode 21 Electrode 22 Groove 30a, 30b, 30c Bioelectrode 31 Insulation lid 32 Thread 40, 40a Bioelectrode 41 Base material 42 Electrode 42 Conductor 43a Protruding portion of conductor 44 Lead wire 45 Thread 46 Shape holding portion 50 Tester 51 Silver-plated copper wire 52 Weight

Claims (8)

A biological electrode that is embedded in a living body and electrically measures nerves and the like,
It consists of a sheet-like insulating substrate, two sheet-like electrodes having flexibility to be fixed on the substrate, and lead wires connected to the electrodes,
The two electrodes are sheet-like bioelectrodes arranged in parallel so that the nerves are arranged on the two electrodes so as to intersect perpendicularly to the electrodes. The sheet-like bioelectrode according to claim 1, wherein a groove for holding the nerve so as not to shift is formed in the two electrodes. The sheet-like bioelectrode according to claim 1, further comprising a sheet-like insulating lid provided on the nerve disposed on the electrode. A biological electrode obtained by stacking two sheet-like biological electrodes according to claim 1 so as to sandwich a nerve. The bioelectrode according to claim 1, wherein an operation thread is provided on the insulating substrate and / or the insulating lid. The bioelectrode according to claim 1, wherein conductive silicone rubber is used as a material for the electrode. The biological electrode according to claim 1, further comprising a thin metal conductor inside the electrode. The biological electrode according to claim 1, further comprising a shape holding portion made of a shape memory material under the substrate.