JP5317265B2 - Wire electrode insertion / fine movement / holding device - Google Patents

Description

  The present invention relates to a device (electrode fine movement device) for inserting at least one wire-like electrode into nerve tissue.

  Single neuronal activity is recorded in freely moving animals to elucidate brain function. A wire electrode is used as an electrode for recording an action potential in a nerve tissue such as the brain. In order to record the action potential change in the nerve tissue, the tip of the wire electrode is delivered to the target site, and more preferably, the nerve action potential that can be recorded during the movement of the electrode is stabilized. Thus, it is desired to record continuously for a long time.

A device for finely moving the tip of a wire electrode in the brain has conventionally existed. However, since the conventional electrode microfibrillation device does not have a cover to protect the wire electrode, it is hardened with polyethylene glycol or the like when the wire is inserted into the deep part of the brain, and is inserted into the nerve tissue before it dissolves. There was a need. In addition, there is no device that can stably record a nerve action potential that can be recorded in the middle of electrode movement for a long period of time. Further, the conventional apparatus is weak against vibration, and there is a problem that the recording of nerve activity is stopped only by the animal shaking his head vigorously or just biting the solid food.
Patent documents 1, 2, and 3 are presented as patent documents related to the present invention.

JP 2001-231759 A Japanese National Patent Publication No. 10-503105 JP 2005-516697 A

  An object of the present invention is to provide a device that can easily deliver the tip of a very thin wire electrode used for recording nerve action potentials or stimulating nerve cells to a target site of nerve tissue.

  It is another object of the present invention to provide an electrode fine movement device capable of stably recording a nerve action potential that can be recorded in the middle of electrode movement for a long period of time.

The present inventors have surprisingly found that the above problem can be solved by the following configuration.
(1) A device for inserting a wire-like electrode into nerve tissue, comprising at least one wire-like electrode, an inner sheath tube, and an outer sheath tube, wherein the at least one wire-like electrode The electrode is fixedly arranged inside the inner sheath tube so that a part including the tip of the electrode protrudes from an opening at one end of the inner sheath tube to form an electrode protruding portion. A part including one end where the opening is formed is inserted inside the outer sheath tube so as to be slidable in the longitudinal direction, and the inner sheath tube is located inside the outer sheath tube and the whole of the electrode protruding portion. Is slidable between a position where the electrode is housed inside the outer sheath tube and a position where a part or all of the protruding portion of the electrode protrudes from an opening at one end of the outer sheath tube. The device according to.

(2) The apparatus according to (1), further including position adjusting means for freely adjusting a position of the inner sheath tube with respect to the outer sheath tube.

(3) The position adjusting means includes a first support plate erected perpendicularly to a longitudinal direction of the inner sheath tube on an outer wall of a portion of the inner sheath tube that is not inserted into the outer sheath tube, A second support plate disposed perpendicularly to the longitudinal direction of the outer sheath tube on the outer wall of the outer sheath tube and disposed opposite to the first support plate; the first support plate and the second support; One of the plates corresponds to the screw shaft of the screw shaft tip side support plate, which is a support plate located on the tip side of the screw shaft among the first support plate, the first support plate, and the second support plate. The same number of screw shafts as the screw shafts are opened at the positions where one of the screw shafts is movably inserted, and the screw shaft is screwed into a portion protruding from the through hole on the tip side of the screw shafts. The positioning nut and the screw shaft tip side support plate that are joined together are positioned. Characterized in that it comprises a biasing means for pressing the positioning nut urges the use nut (2) Apparatus according.

(4) The two screw shafts are provided, and the screw shaft tip side support plate and the tube in which the screw shaft tip side support plate is provided on the outer wall of the inner sheath tube and the outer sheath tube are bent. The positions of the end portions of the positioning nuts screwed onto the two screw shafts that contact the screw shaft tip side support plate are different from each other in the longitudinal direction of the screw shaft. The screw shaft tip side support plate having flexibility and the tube are bent by adjusting to be, and the bent screw shaft tip side support plate and the tube are restored to return to the original shape. A part of the outer wall of the inner sheath tube and a part of the inner wall of the outer sheath tube are pressed against each other by force, and the inner sheath tube is fixed to the outer sheath tube. The device according to (3), characterized in that

(5) The urging means is arranged to be compressed around an axis of a portion of the screw shaft between the first support plate and the second support plate, and the screw shaft tip side support plate is used as the screw shaft. The device according to (3) or (4), characterized in that the device is constituted by an extension spring that is urged toward the distal end of the device.

(6) The screw shaft is fixedly arranged perpendicularly to a side of the second support plate facing the first support plate, according to any one of (3) to (5), Equipment.

  According to the apparatus of the present invention, the tip of a very thin wire electrode used for recording nerve action potentials or stimulating nerve cells can be delivered to a target site of nerve tissue without damaging the electrodes.

  Furthermore, according to the embodiment of the apparatus of the present invention having the position adjusting means, it is possible to stably and continuously record the nerve action potential that can be recorded during the movement of the electrode in the nerve tissue. It becomes.

  The structure and function of an embodiment of the apparatus according to the present invention will be described with reference to FIG.

  According to the present invention, an electrode fine movement device 10 for inserting a wire-like electrode into nerve tissue includes at least one (eight in the example shown in FIG. 1) wire-like electrodes 11, an inner sheath tube 12, And at least an outer sheath tube 13. The inner peripheral surface of the outer sheath tube 13 and the outer peripheral surface of the inner sheath tube 12 are in slidable contact. At least one wire-like electrode 11 is fixedly arranged inside the inner sheath tube 12 so that a part including the tip of the electrode 11 protrudes from the opening 14 at one end of the inner sheath tube 12 to form an electrode protruding portion 11 ′. Has been. Furthermore, a portion including one end where the opening 14 of the inner sheath tube 12 is formed is inserted inside the outer sheath tube 13 so as to be reciprocally movable in the longitudinal direction. The inner sheath tube 12 is positioned inside the outer sheath tube 13 so that the entire electrode protruding portion 11 ′ is accommodated inside the outer sheath tube 13 (for example, FIG. 1B) and the electrode protruding portion 11 ′. A part or all of the outer sheath tube 13 can slide between positions protruding from the opening 15 at one end of the outer sheath tube 13 (for example, FIG. 1A). With such a configuration, when the electrode 11 is brought close to the vicinity of the target site in the nerve tissue, the electrode 11 is protected by the outer sheath tube 13, and the electrode protruding portion 11 ′ is exposed at the target site in the nerve tissue. It is possible to record neural activity or stimulate nerve cells.

  That is, according to the present invention, even when targeting a nerve cell population deep from the brain surface, it is possible to proceed to the vicinity without risk of electrode damage or bending.

  When a plurality of wire electrodes are used, the arrangement of the tips can be appropriately determined according to the purpose. For example, at least one tip of the plurality of wire-like electrodes may be disposed at a different position in the axial direction of the assembly of wire-like electrodes as compared to the tips of the other wire-like electrodes. The tips of the wire electrodes may be arranged at the same position in the axial direction of the assembly of wire electrodes. Furthermore, each tip may be arranged so that a gap is generated between the side surfaces of the tips of adjacent wire electrodes, or each tip is arranged so that the side surfaces of the tips of adjacent wire electrodes are in close contact with each other. It may be. As shown in FIG. 1, the protruding portions 11 ′ of the plurality of wire-like electrodes are arranged so that the maximum outer diameter is larger than the inner diameter of the outer sheath tube in different directions starting from the opening 14 of the inner sheath tube 12. When the inner sheath tube 12 is bent in a divergent shape, the distance between the tips of the electrodes can be changed by sliding the inner sheath tube 12 with respect to the outer sheath tube 13.

  The wire electrode is composed of, for example, a conductive linear core material and an insulating coating layer that covers the outer periphery of the linear core material so that the linear core material can come into contact with the outside at the tip. What was formed is mentioned. Although the material which comprises a linear core material is not specifically limited as long as it is an electroconductive material, Typically, Nichrome, tungsten, stainless steel, platinum iridium etc. can be illustrated. Examples of the thickness of the linear core material include 5 to 80 μm. The length of the linear core material can be appropriately changed according to the measurement site or the like, and is typically about several tens of cm, for example, 10 to 20 cm. Although the material which comprises a coating layer is not specifically limited as long as it is an insulating material, It is preferable to use resin, such as an epoxy resin. The thickness of the coating layer is preferably 3 to 20 μm. The number of wire electrodes can be determined as appropriate.

  The configuration of FIG. 1 will be described in more detail. The inner sheath tube 12 is a hollow tubular member having an opening 14 at one end. The outer sheath tube 13 is a hollow tubular member having an opening 15 at one end. The inner peripheral surface of the outer sheath tube 13 and the outer peripheral surface of the inner sheath tube 12 are in slidable contact. The outer sheath tube 13 is shorter than the inner sheath tube 12. The inner sheath tube 12 is inserted into the outer sheath tube 13 so that the opening 14 and the opening 15 face in the same direction and can slide in the longitudinal direction. A side wall opening 16 that connects the inner space of the inner sheath tube 12 and the outside is formed on the side wall of the inner sheath tube 12 at a different end side from the opening 14 of the inner sheath tube 12. The plurality of wire-like electrodes 11 have their tips protruding from the openings 14 (the protruding portions are referred to as “electrode protruding portions 11 ′”), and the other ends (hereinafter referred to as “electrode rear end portions 11 ″”) are side walls. It is fixedly disposed in the inner space of the inner sheath tube 12 so as to appear outside from the opening 16. At this time, in the embodiment using a plurality of wire-like electrodes, the wire-like electrode 11 is such that each electrode protruding portion 11 ′ faces a different direction within an angle range of less than 90 ° with respect to the opening direction of the opening 14. It is preferable that the inner sheath tube 12 is bent in the vicinity of the opening 14. The wire electrode 11 is fixed to the inner sheath tube 12 by injecting an adhesive 17 from the side wall opening 16.

  Further, although not shown because it overlaps with the wire electrode 11, an adhesive is injected into the inner sheath tube 12 from the opening 14, and the wire electrode 11 is fixed to the inner sheath tube 12 in the vicinity of the opening 14. The In the case where the opening 15 side end (outer sheath tube tip) of the outer sheath tube 13 is located on the tip side in the longitudinal direction of the inner sheath tube than the opening 14 side end (inner sheath tube tip) of the inner sheath tube 12, When the distance L from the distal end of the inner sheath tube to the distal end of the outer sheath tube is smaller than the length of the wire electrode protruding portion 11 ′, a part from the distal end of the electrode protruding portion 11 ′ is exposed to the outside. When the outer sheath tube tip and the inner sheath tube tip are located at the same position in the inner sheath tube longitudinal direction, or the outer sheath tube tip is located at the rear end side with respect to the inner sheath tube longitudinal direction than the inner sheath tube tip. In this case, the entire electrode protruding portion 11 ′ is exposed to the outside. FIG. 1A shows a case where the outer sheath tube tip and the inner sheath tube tip are located at the same position in the longitudinal direction of the inner sheath tube. In FIG. 1 (b), the outer sheath tube tip is located closer to the tip side in the longitudinal direction of the inner sheath tube than the inner sheath tube tip, and the distance L is the same as the length of the protruding portion 11 ′. Show. At this time, the wire electrode protruding portion 11 ′ is stored inside the outer sheath tube 13 and is not exposed to the outside.

  In the embodiment shown in FIGS. 1 and 2, the electrode rear end portion 11 ″ is led to the outside through the side wall opening 16 of the inner sheath tube 12, but this is not limitative. In another embodiment, the electrode rear end portion 11 ″ is guided to the outside through the opening at the end opposite to the end on the opening 14 side of the inner sheath tube 12. In the other embodiment, the wire electrode can be fixed by injecting an adhesive into the inner sheath tube 12 from the opening through which the electrode rear end portion 11 ″ passes.

  The device of the present invention preferably further includes a position adjusting means for freely adjusting the position of the inner sheath tube 12 with respect to the outer sheath tube 13. By providing the position adjusting means, the wire electrode can be finely moved in the nerve tissue. Further, it becomes easy to finely adjust the length of insertion of the wire electrode 11.

  The configuration and function of a further preferred embodiment of the present invention including the position adjusting means will be described with reference to FIG. 2A is a top view of the apparatus shown in FIG. 2A, and FIG. 3B is a bottom view of the apparatus shown in FIG.

  The position adjusting means in the present invention includes a first support plate 21 erected perpendicularly to the longitudinal direction of the inner sheath tube 12 on the outer wall of the inner sheath tube 12 that is not inserted into the outer sheath tube 13, and the outer side. On the outer wall of the sheath tube 13, a second support plate 22, which is erected perpendicularly to the longitudinal direction of the outer sheath tube 13, is arranged opposite to the first support plate 21, and the first support plate 21 and the second support At least one of the plates 22 (the second support plate 22 in FIGS. 2 and 3) fixedly arranged vertically on the side facing the other of the first support plate 21 and the second support plate 22 (FIGS. 2 and 3). The two screw shafts 23 and the screw shaft front end side support plate (the first in FIG. 2 and FIG. 3) which is a support plate located on the front end side of the screw shaft among the first support plate and the second support plate. The same number of screw shafts 23 opened at positions corresponding to the screw shafts 23 of the support plate 21) A through hole into which one of the screw shafts 23 is movably inserted, a positioning nut 27 screwed into a portion protruding from the through hole on the tip side of the screw shaft 23, and the screw shaft tip side Biasing means for biasing and pressing the support plate toward the positioning nut 27.

  The urging means is preferably arranged by being compressed around the axis of the portion of the screw shaft 23 between the first support plate 21 and the second support plate 22, and the other first or second support plate is screwed. The extension spring 26 is urged toward the distal end of the shaft 23.

  Preferably, there are two screw shafts 23 as shown in FIGS. 2 and 3, and the screw shaft tip side support plate is flexible. When only the positioning nut 27 screwed into one of the two screw shafts 23, 23 is moved, the electrode protruding portion 11 ′ moves only a half of the moving distance of the positioning nut 27. Therefore, it is possible to finely adjust the movement distance of the electrode. Although it is difficult to reduce the pitch of the grooves of the screw shaft 23, if the two screw shafts 23, 23 are provided and the screw shaft tip side support plate is made of a flexible material, An effect equivalent to halving the pitch of the grooves can be obtained. In the embodiment provided with two screw shafts 23, a tube (not only the screw shaft tip side support plate but also the inner shaft tube 12 and the outer sheath tube 13 of which the screw shaft tip side support plate is provided on the outer wall ( In FIG. 2, the inner sheath tube 12) is preferably flexible. At this time, by adjusting the positions of the end portions of the positioning nuts 27, 27 on the two screw shafts that are in contact with the screw shaft tip side support plate so as to be different from each other in the longitudinal direction of the screw shaft, One of the outer wall of the inner sheath tube 12 is bent by the bending force of the shaft tip side support plate and the flexible tube, and the bending force of the screw shaft tip side support plate and the tube to return to the original shape. And a part of the inner wall of the outer sheath tube 13 are pressed against each other, and the inner sheath tube 12 is fixed to the outer sheath tube 13.

  FIG. 4C shows that the first support plate 21 and the inner sheath tube 12 that are the screw shaft tip side support plates are bent, and the axis of the inner sheath tube 12 is slightly inclined with respect to the axis of the outer sheath tube 13. The example which fixes the inner sheath pipe | tube 12 by doing is shown. For easy understanding in FIG. 4C, the shaft and the outer portion of the inner sheath tube 12 that is not inserted into the outer sheath tube (the portion that does not flex) from the screw shaft tip side support plate. Although the angle formed with the axis of the sheath tube 13 is exaggerated, it is actually preferable that the angle be in the range of about 0.5 to 5 °. As a result, even if the experimental animal to which the electrode fine movement device is fixed moves vigorously, or even when a part of the electrode fine movement device collides with the wall, the recorded nerve activity is not easily lost. The deformation rate of the screw shaft front end side support plate is preferably smaller than the deformation rate of the flexible tube provided with the screw shaft front end side support plate. The flexible screw shaft tip side support plate and the flexible tube provided with the screw shaft tip side support plate are positioned at the ends of the positioning nuts 27 and 27 that are in contact with the screw shaft tip side support plate. Can be restored to their original shape by the restoring force of each of the screw shafts at the same position with respect to the longitudinal direction of the screw shaft.

  The positioning nut 27 is preferably a nut with a nylon lock in order to prevent loosening due to vibration caused by movement of an animal.

  The screw shaft 23 is preferably fixedly arranged vertically on the side of the second support plate 22 facing the first support plate 21.

  The method for fixing the screw shaft 23 is not particularly limited. For example, as shown in FIGS. 2 and 3, when a screw head 28 having an enlarged diameter is formed at the base portion of the screw shaft 23, the first support plate 21. Alternatively, the screw shaft 23 is passed through an insertion hole formed on one side of the second support plate 22 and having a diameter smaller than that of the screw head 28 and larger than that of the screw shaft 23, and the screw head from the distal end side of the screw shaft 23. The screw shaft 23 can be fixed by screwing and tightening the fixing nut 24.

  2 and 3 show a preferred embodiment of the present invention in which two screw shafts 23, 23 are fixed on the second support plate 22. The present invention will be described in more detail with reference to FIGS. The first support plate 21 and the second support plate 22 each have two screw shaft through holes (not shown), and are formed at positions facing each other when the first support plate 21 and the second support plate 22 are opposed to each other. Has been. The two screw shafts 23, 23 are arranged in parallel so that the heads 28, 28 are on the second support plate 22 side and the shaft tip is on the first support plate 21 side, respectively. The screw heads 28 and 28 are fixed to the second support plate 22 by tightening the screw head fixing nuts 24 and 24 to the second support plate 22 side. Further, spring support nuts 25 and 25 for supporting one end of extension springs 26 and 26, which will be described later, are screwed onto the screw shafts 23 and 23 on the tip side of the screw head fixing nuts 24 and 24, respectively. The extension springs 26 and 26 are compressed and arranged between the surface on the screw shaft tip side of the spring support nuts 25 and 25 and the surface on the screw head side of the first support plate 21. Each of the extension springs 26 and 26 urges the first support plate 21 toward the tip end of the screw shaft. Positioning nuts 27 and 27 are screwed into the screw shafts 23 and 23 on the tip side of the first support plate 21. The inner sheath tube 12 fixed to the first support plate 21 can be sent out in the distal direction of the outer sheath tube 13 by turning the positioning nuts 27 and 27 in the tightening direction. On the other hand, the inner sheath tube 12 can be retracted in the reverse direction by turning the positioning nuts 27, 27 in the loosening direction. FIG. 2A is a view showing a state in which the positioning nuts 27 are loosened. At this time, all the wire electrode protruding portions 11 ′ are stored in the outer sheath tube 13. The internal structure of the tip in FIG. 2 (a) corresponds to FIG. 1 (b). FIG. 2B is a diagram showing a state in which the positioning nuts 27 are tightened. At this time, the protruding portion 11 ′ of the wire electrode is exposed to the outside through the opening 15 of the outer sheath tube 13. The internal structure of the tip in FIG. 2 (b) corresponds to FIG. 1 (a).

  In this way, by appropriately adjusting the tightening positions of the positioning nuts 27, 27, the protruding length of the protruding portion 11 'of the wire electrode from the outer sheath tube 13 can be freely adjusted. Further, by adjusting the position of the spring supporting nuts 25, 25 on the screw shafts 23, 23, the relationship between the magnitude of the urging force by the extension springs 26, 26 and the protruding length of the wire electrode protruding portion 11 ′. Can be adjusted freely. Although not shown in FIGS. 1 and 2, the electrode rear end portion 11 ″ is electrically connected to a device for recording a potential change.

  Next, an outline of a procedure for delivering the wire electrode tip portion 11 ′ into the brain tissue using the apparatus of the present invention will be described with reference to FIG. 4. As shown in FIG. 4A, first, the experimental animal is anesthetized and a hole 41 is opened in a part of the skull 40. Next, as shown in FIG. 4B, the outer sheath tube 13 of the electrode fine movement device 10 of the present invention is inserted to a predetermined position in the brain tissue 42 in a state where the wire-like electrode tip portion 11 ′ is stored. . Further, the electrode fine movement device 10 is fixed to the skull 40 with an adhesive 43 such as acrylic resin. When using an adhesive that does not adhere to bone, such as acrylic resin, adhesion is assisted by attaching anchor bolts 44, 44 to the skull 40. As shown in FIG. 4, the positions of the spring support nuts 25, 25 can be appropriately adjusted so that the urging force of the extension springs 26, 26 is maximized when the tip of the electrode reaches a desired target site. it can. Next, as shown in FIG. 4C, after the experimental animal recovers, the wire-like electrode protruding portion 11 ′ is sent to a desired position in the brain tissue 42 to record neural activity.

  In this example, the device shown in FIGS. 2 and 3 was manufactured, and the nerve action potential in the rat brain was recorded according to the procedure shown in FIG. A stainless steel tube having an outer diameter of 0.6 mm and an inner diameter of 0.3 mm was used as the inner sheath tube 12, and a stainless steel tube having an outer diameter of 0.9 mm and an inner diameter of 0.6 mm was used as the outer sheath tube 13. As the wire electrode 11, eight wire electrodes obtained by the following procedure (a nichrome wire with a diameter of 40 μm is covered with an epoxy coating with a thickness of 12 μm and the tip is subjected to the treatment described later) are used. did. The length of the protruding portion 11 ′ of the wire electrode was 7 mm. In the apparatus used in the present embodiment, if the protruding length (movement distance) of the protruding portion 11 ′ of the wire-like electrode fed from the opening 15 of the outer sheath tube 13 is about 3 mm, the bundle of the protruding portions 11 ′ is It does not spread radially. If you move it further, it will gradually spread.

  First, the distal end of the outer sheath tube 13 was inserted into the rat brain in a state where the wire electrode 11 was completely stored inside the outer sheath tube 13 (that is, the state of FIG. 2A). Specifically, the rat was anesthetized with pentobarbital (50 mg / kg) and fixed to a stereotaxic device, and a hole of about 2 mm was made in the skull 2 mm behind Bregma and 0.5 mm right from the midline, 5.5 mm from the brain surface. The distal end of the outer sheath tube 13 was inserted to a depth of 5 mm and fixed with acrylic resin in the inserted state. The distal end of the outer sheath tube 13 was positioned 2 mm above the hypothalamic paraventricular nucleus. Before waking up from anesthesia, a recording preamplifier was connected to the electrode rear end portion 11 ″ via a connector.

  Waiting for sufficient recovery of the rat, recording was performed while the two positioning nuts 27 and 27 were alternately turned in the tightening direction to send out and move the tip of the wire electrode and moved closer to the target site after about 3 days. . The point where the tip of the wire electrode moved 3 mm was taken as the end point.

  An example of the measurement result by the electrode of this invention is shown in FIG. In FIG. 5, action potentials having a certain amplitude or larger are cut out and superimposed for each electrode (# 1 to # 8).

  With the electrode of the present invention, an activity with a maximum amplitude of 1.5 mV could be recorded in 6 to 7 of the 8 electrodes. In the example shown in FIG. 5, about 1 mV of activity could be recorded simultaneously in # 3 and # 7. A number of activities other than # 3 and # 7 were also recorded for a plurality of activities of 100 to 200 microvolts. In addition, while the 8 electrodes were simultaneously moved 3 mm in the brain, 1 mV class activity was recorded on the electrodes other than # 3 and # 7. During movement, neural activity was recorded at each electrode without interruption, although the amplitude varied.

The wire electrode used in this experiment was prepared by the following procedure.
1. Electrode creation
1.1. Preparation of Epoxy Film A nichrome wire having a diameter of 40 μm was cut into 15 centimeters, and a weight was applied to the lowermost part to hang it vertically. A brush containing epoxy was applied to it, and the required length was moved downward, and then the brush was released. The same operation was performed once again with the direction changed by 180 degrees. After drying at room temperature for about 5 minutes, it was placed in an oven and heated at 100 ° C. for 20 minutes and further at 180 ° C. for 30 minutes. This operation (application to warming) was repeated 10 times. The thickness of the epoxy film thus obtained was 12 μm. One end was cut with scissors to produce a primary electrode.

1.2. Mechanically polished Diamond powder fixed to the tip of a small motor shaft was rotated at high speed, and the tip of the primary electrode obtained in 1.1 was brought into contact. A secondary electrode having a tapered tip was obtained by gradually shifting the three-dimensional positional relationship between the small motor and the electrode.

1.3. The tip of the secondary electrode obtained in electrolysis 1.2 and a silver wire as a counter electrode are both immersed in saline, the positive side of the constant current device is used as the secondary electrode, and the negative side is used as the silver wire. Each was connected and energized. Energization was performed at 5 microamperes for 12 minutes. A cavity having a depth of 110 micrometers was formed at the tip of the electrode of the present invention thus obtained.

It is the cross-sectional schematic diagram of the front-end | tip part of the electrode fine movement apparatus provided with the multiple (8 pieces) wire-like electrode which it created and used in the Example. FIG. 3 is a perspective view of an electrode fine movement device that includes a plurality of (8) wire-like electrodes that are created and used in an embodiment and includes position adjusting means for freely adjusting the protruding length of the wire-like electrode. FIG. 3 shows a top view and a bottom view of the apparatus shown in FIG. The procedure for measuring the action potential in the brain using the electrode microtremor device of the present invention will be described. The recording result of the nerve action potential when eight electrodes of the present invention are combined is shown for each electrode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrode fine-movement apparatus 11 ... Wire-like electrode 11 '... Wire-like electrode protrusion part 11''... Electrode rear end part 12 ... Inner sheath tube 13 ... Outer sheath tube 14- .... Opening 15 of inner sheath tube ... Opening 16 of outer sheath tube ... Side wall opening 17 of inner sheath tube ... Adhesive 21 ... First support plate (screw shaft tip side support plate)
22 ... second support plate 23 ... screw shaft 24 ... screw head fixing nut 25 ... spring support nut 26 ... extension spring 27 ... positioning nut 28 ... screw Head 40 ... Skull 41 ... Hole 42 ... Brain tissue 43 ... Adhesive 44 ... Anchor bolt

Claims (5)

A device for inserting a wire-like electrode into nerve tissue,
At least one wire-like electrode, an inner sheath tube, and an outer sheath tube,
The at least one wire-like electrode is fixedly arranged inside the inner sheath tube so that a part including the tip of the electrode protrudes from an opening at one end of the inner sheath tube to form an electrode protruding portion. ,
A part including one end where the opening of the inner sheath tube is formed is inserted inside the outer sheath tube so as to be slidable in a longitudinal direction,
The inner sheath tube is located inside the outer sheath tube at a position where the entire electrode protruding portion is accommodated inside the outer sheath tube, and a part or all of the electrode protruding portion is at one end of the outer sheath tube. Slidable between the position protruding from the opening ,
The apparatus according to claim 1, further comprising position adjusting means for freely adjusting a position of the inner sheath tube with respect to the outer sheath tube . The position adjusting means includes
A first support plate erected perpendicularly to the longitudinal direction of the inner sheath tube on the outer wall of the inner sheath tube that is not inserted into the outer sheath tube;
A second support plate disposed on the outer wall of the outer sheath tube perpendicular to the longitudinal direction of the outer sheath tube and disposed opposite to the first support plate;
At least one screw shaft fixedly arranged vertically on one side of the first support plate and the second support plate facing the other of the first support plate and the second support plate;
The screw shaft opened at a position corresponding to the screw shaft of a screw shaft tip side support plate, which is a support plate located on the tip side of the screw shaft among the first support plate and the second support plate; The same number of through-holes into which one of the screw shafts is movably inserted,
A positioning nut screwed into a portion protruding from the through hole on the tip side of the screw shaft;
Characterized in that it comprises a biasing means for pressing the urging by the positioning nut towards the screw shaft distal end side supporting plate to the positioning nut device according to claim 1. Two screw shafts are provided,
The screw shaft tip side support plate and the tube of the inner sheath tube and the outer sheath tube, on which the screw shaft tip side support plate is provided on the outer wall, each have flexibility.
By adjusting the positions of the end portions of the positioning nuts screwed onto the two screw shafts to be in contact with the screw shaft tip side support plate so as to be different from each other in the longitudinal direction of the screw shaft. The inner sheath tube is deformed by bending the screw shaft tip side support plate having flexibility and the tube, and the bending force of the bent screw shaft tip side support plate and the tube to return to the original shape. A part of the outer wall of the outer sheath tube and a part of the inner wall of the outer sheath tube are pressed against each other, and the inner sheath tube is configured to be fixed to the outer sheath tube. Item 3. The apparatus according to Item 2 . The biasing means is arranged to be compressed around an axis of a portion of the screw shaft between the first support plate and the second support plate, and the screw shaft tip side support plate is arranged in the tip direction of the screw shaft. characterized in that it is constituted by a biasing extending spring apparatus according to claim 2 or 3 wherein. The apparatus according to any one of claims 2 to 4 , wherein the screw shaft is fixedly arranged perpendicularly to a side of the second support plate facing the first support plate.

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