JP5139007B2 - Observation drill - Google Patents

Description

The present invention relates to observations for drilling equipment.

  Conventionally, as a method of observing the brain function of an animal or the like, a method of measuring an electroencephalogram by inserting an electrode into a brain tissue has been performed (see, for example, Patent Document 1). Since the brain potential measurement is a measurement of the potential at the point where the electrode is pierced, there is a disadvantage that the observable range is very narrow.

  In contrast, optical observation allows two-dimensional observation over a relatively wide range, and furthermore, if a confocal optical system is used, three-dimensional observation is also possible. It is desired to optically observe brain functions.

Japanese Patent No. 3204875

  However, when observing brain function optically, especially when observing the deep part of the brain, the brain tissue is pierced through a through-hole formed in the skull, and a small-diameter objective is formed in the opened hole. It is necessary to insert the tip of the lens and observe the bottom surface of the hole, but when puncturing, the brain cells are crushed and destroyed, or the observation surface formed on the bottom surface of the hole is uneven by the destroyed brain tissue There is an inconvenience of being formed.

The present invention was made in view of the above circumstances, without destroying the tissue structure and cells of the body tissue, Ru can be formed a substantially cylindrical bore having a flat viewing surface to the bottom surface It is an object of the present invention to provide the police for drilling tart.

In order to achieve the above object, the present invention provides the following means.
The present invention is an observation surface cutter for forming a substantially cylindrical hole having a flat observation surface on a bottom surface of a living tissue, and a circumferential blade portion extending in the circumferential direction at the tip of the cylindrical body, and at least comprising a radial blade portion extending radially from the center of the cylindrical body, and a tension adjusting mechanism for adjusting the tension of the wire, the radial cutting portion, ing from wires looped around in the circumferential direction cutting section observation A surface cutter and a cylindrical guide member having an annular cutting edge at the tip thereof, and the observation surface cutter is removably fitted inside the guide member, and the guide member Provides a drilling tool for observation that is rotatably supported in the circumferential direction .
According to the present invention, the distal edge is brought into contact with the surface of the biological tissue and rotated around the axis, whereby the circumferential blade portion forms a cylindrical cut in the biological tissue, and the radial blade portion of the cut. The internal biological tissue can be cut in a direction intersecting the axis. That is, the cylindrical body is rotated around the axis while the tip position of the cylindrical body is fixed in the axial direction at a desired depth position, and the observation surface cut flat by the radial blade portion is provided on the bottom surface. A substantially cylindrical hole can be easily formed. In this case, since the living tissue is cleanly cut by the radial blade portion, it is not crushed and destroyed, and an optically clear observation image can be acquired.

In the present invention, the radial cutting portion, between this consisting of wires stretched in the circumferential direction cutting unit, the circumferential edge portion can turn formed thin by wire, viewed in the axial direction toward the tip When the area can be minimized. Therefore, even when the tip is brought into contact with the surface of the living tissue and pressed in the axial direction, the incision can be easily formed in the living tissue with a small pressing force.

In the present invention, the in and this with a tension adjusting mechanism for adjusting the tension of the wire to adjust the tension of the wire by the operation of the tension adjusting mechanism, to prevent deterioration of the cutting ability of the wire slack, flat A simple observation surface can be formed.

Further , according to the present invention, the annular cutting edge over the entire circumference of the guide member is brought into contact with the surface of the living tissue, pressed in the axial direction, or rotated around the axis, thereby making the annular cut. After the formation, an observation cutter can be inserted inside the guide member to cut out the living tissue disposed inside the annular cut. The observation cutter can be stably rotated using the guide member cut into the living tissue as a guide, and a substantially cylindrical hole having a flat observation surface on the bottom surface can be easily formed.

In the above SL invention, in the circumferential direction cutting section, cut-apart 180 ° circumferentially provided, may be said wire is engaged with the notch.
By doing so, the wire can be maintained at a predetermined position against the reaction force that the wire receives from the living tissue in the direction perpendicular to the axis when the observation surface cutter is rotated around the axis. . Therefore, it is possible to prevent inconvenience that the wire is disconnected during the cutting operation and the radial blade portion is lost.

Further, in the above invention, a stepped portion that tapers toward the tip is provided on the outer peripheral surface of the guide member, and the guide member is rotatably supported, and the stepped portion of the guide member is axially supported. It is good also as providing the abutting surface to abut and the supporting member provided so that position adjustment is possible to the axial direction of a guide member.

  In this way, when the guide member is pressed in the axial direction with respect to the position-adjusted support member or rotated around the axis line to form an annular cut in the living tissue, the abutment surface of the support member Further, the stepped portion of the guide member hits in the axial direction, and further cutting by the guide member is prohibited. Therefore, by adjusting the position of the support member, the depth of cut by the guide member can be adjusted with high accuracy, and a hole having an observation surface at a desired depth can be easily formed.

  Moreover, in the said invention, the said guide member has a main-body part which has the said step part, a front-end | tip part which has an annular cutting blade attached to the main-body part so that attachment or detachment is possible to an axial direction, this front-end | tip part, It is good also as providing the fixing means which fixes the said main-body part so that it may not rotate relatively in the circumferential direction.

  By doing so, an annular incision is formed in the living tissue with the main body portion and the distal end fixed by the fixing means, and the living tissue in the incision is cut out by the observation surface cutter to obtain a flat observation surface. After forming the cylindrical hole having, the fixing by the fixing means is released and the main body is separated from the tip, thereby leaving the tip cut into the living tissue. Since the tip is placed so as to surround the hole formed, body fluid such as blood from the surrounding living tissue is prevented from flowing into the hole, and the observation surface is kept clean. In addition, optical observation can be facilitated.

Further, the reference example of the present invention comprises a metal film obtained by forming a metal film by electroforming on the surface of a substantially cylindrical mold member having a slope inclined with respect to the axis at the tip, and drawing the mold member. A radius extending from the cylindrical material at least in the radial direction from the center of the cylindrical body by cutting off the tip portion by a plane perpendicular to the axis passing through the middle position of the inclined portion of the metal film formed on the inclined surface of the mold member Provided is a method for manufacturing an observation surface cutter in which a directional blade portion is formed and a peripheral edge portion extending in the circumferential direction is formed by cutting or grinding an outer peripheral edge of a tip of a cylindrical body.
By doing in this way, the substantially cylindrical observation surface cutter which has a circumferential direction blade part and a radial direction blade part at the front-end | tip can be manufactured easily.

In the above reference example , the inclined surface of the mold member may be formed on one side of a plane including the axis, and a substantially semi-elliptical region constituted by a plane orthogonal to the plane.
By doing in this way, the observation surface cutter having one radial blade portion extending radially outward from the center and one circumferential blade portion extending over 3/4 rounds at the tip of the cylindrical body is provided. It can be manufactured easily.

Further, in the above reference example , the inclined surface of the mold member is composed of two substantially semi-elliptical regions formed on both sides of the plane including the axis line by planes orthogonal to the plane and inclined in the opposite direction. It is good as well.
By doing in this way, the cutter for observation surfaces which has two radial blade parts extended in the radial direction outward from the center, and two circumferential blade parts extended over 1/4 turn at the tip of a cylindrical body Can be easily manufactured.

  According to the present invention, there is an effect that a substantially cylindrical hole having a flat observation surface on the bottom surface can be formed without destroying the tissue structure or cells of the living tissue.

Hereinafter, the observation surface cutter 1 according to the first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, an observation surface cutter 1 according to the present embodiment includes a cylindrical cutter body (cylindrical body) 3 having an annular cutting edge (circumferential blade part) 2 at the tip. , A wire (radial blade portion) 5 spanned by two notches 4 provided 180 degrees apart in the circumferential direction on the cutting blade 2 of the cutter body 3, and a tension adjusting mechanism for adjusting the tension of the wire 5 6 is provided. The thickness of the wire 5 is preferably about 0.05 mm or less. Further, the depth of the notch 4 is substantially equal to the thickness of the wire 5.

In the vicinity of the two notches 4 of the cutter body 3, there are provided through holes 7 penetrating in the radial direction respectively, and both ends of the wire 5 spanned through the notches 4 are inserted into the cutter body 3 through the through holes 7. Then, it is connected to the tension adjusting mechanism 6.
The wire 5 is wound around the center of the annular cutting blade 2, that is, a position passing through the central axis C of the cutter body 3.

  The tension adjusting mechanism 6 is fitted to the male screw 8 provided on the outer peripheral surface of the cutter main body 3, the nut 9 fastened to the male screw 8, and the cutter main body 3 so as to be movable in the axial direction. And a piece member 10 having a wire fixing portion 10a for fixing both ends of the frame. By rotating the nut 9 in one direction with respect to the male screw 8 and moving it away from the cutting blade 2, the piece member 10 is moved away from the cutting blade 2 so that the tension applied to the wire 5 can be increased. It has become. Further, the tension applied to the wire 5 can be reduced by rotating the nut 9 in the reverse direction.

  In order to form the cylindrical hole B in the living tissue A using the observation surface cutter 1 according to the present embodiment configured as described above, the tension adjusting mechanism 6 is operated to appropriately adjust the tension of the wire 5. To do. Next, as shown in FIG. 3A, the tip of the observation surface cutter 1 is brought close to the surface of the living tissue A and pressed to press in the axial direction. As a result, as shown in FIG. 3 (b), the distal end of the observation surface cutter 1 is desired to be cut while cutting the living tissue A by the large contact pressure received from the thin distal end of the annular cutting blade 2 and the thin wire 5. It can be pushed to the depth position.

Alternatively, by pushing the cutter body 3 while rotating around the axis C, the living tissue A inside the cutter body 3 is formed by the wire 5 while the annular cutting edge 2 is formed in the living tissue A. The tip of the observation surface cutter 1 can be pushed to a desired depth position while being cut in a spiral shape.
Moreover, since the wire 5 is engaged with the notch 4, it is possible to prevent the wire 5 from being displaced and maintain the cutting ability.

  From this state, as shown in FIG. 3 (c), by rotating the observation surface cutter 1 about its axis C, the wire 5 stretched around the cutting blade 2 is rotated about the axis C of the cutter body 3. Rotate to Since the wire 5 is stretched at a position passing through the axis C of the cutter body 3 so as to be orthogonal to the axis C, when the wire 5 is rotated around the axis C, the wire 5 is placed inside the cutter body 3 at the tip end position of the cutter body 3. The existing biological tissue A is cut along a plane orthogonal to the axis C. Then, the entire body tissue A existing inside the cutter body 3 can be cut without leaving the entire body by rotating the cutter body 3 at least half a circle.

Thereafter, as shown in FIG. 3D, the observation surface cutter 1 is pulled out from the living tissue A, so that the cylindrical hole B having the observation surface D flatly cut by the wire 5 on the bottom surface becomes the living body. It will be formed in organization A. The cut biological tissue A is caught by the wire 5 and removed at the time of extraction. Even if it remains in the hole B without being removed, it can be easily removed by suction or washing.
Further, when the observation cutter 1 is pulled out, the cut biological tissue A hardly remains in the hole B by closing the hole on the terminal surface (the surface on which the wire 5 is not provided) of the cutter body 3 with a finger or the like. can do.

  That is, according to the observation surface cutter 1 according to the present embodiment, not only an annular cut can be formed in the living tissue A, but also flat observation can be performed without crushing cells on the bottom surface or destroying the tissue structure. Surface D can be formed by cutting. Therefore, there is an advantage that a two-dimensional or three-dimensional optical observation of a healthy living tissue A can be performed by inserting a small-diameter objective lens (not shown) into the formed hole B.

In the present embodiment, the case where the tip of the cutter body 3 has the annular cutting blade 2 over the entire circumference has been described. Instead, the cutting blade 2 is provided only in a part of the circumferential direction. It may be.
In addition, the wire 5 is passed through the cutter body 3 through the through hole 7 that penetrates the cutter body 3 in the radial direction. Instead, as shown in FIG. It may be passed through the hole 7. Reference numeral 11 in the drawing is a groove provided on the outer peripheral surface of the cutter main body 3 for accommodating the wire 5.
In addition, although the tension adjusting mechanism including the male screw 8, the nut 9, and the piece member 10 has been illustrated, other arbitrary mechanisms may be employed instead.

Next, the observation surface cutter 20 and the manufacturing method thereof according to the second embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 5, the observation surface cutter 20 according to the present embodiment includes a circumferential blade portion 22 extending in the circumferential direction over 3/4 rounds at the tip of a substantially cylindrical cutter body 21, and 1 / A radial blade portion 23 that projects radially inward in an area of four rounds and extends in the radial direction at one end edge thereof is integrally provided.

The observation surface cutter 20 according to the present embodiment can be easily manufactured by the following manufacturing method.
First, as shown in FIG. 6 and FIG. 7A, a mold 24 made of a cylindrical metal material having a slope 24a at the tip is prepared. The inclined surface 24a is formed, for example, in a shape that is scraped with a constant gradient only on one side with respect to the plane P including the central axis C of the mold 24.

  Next, the surface of the mold 24 is subjected to, for example, nickel plating (electrocasting) to cover the outer peripheral surface and the end surface provided with the inclined surface 24a, as shown in FIG. 7B. (Metal film) 25 is formed. The plated layer 25 is formed to have a sufficient thickness dimension that can maintain rigidity. After the plating layer 25 is formed, the mold 24 is extracted from the inside, thereby forming a cylindrical portion 26 formed at a position covering the outer peripheral surface of the mold 24 and a position covering the inclined surface 24 a of the mold 24. A cylindrical material 28 having an inclined portion 27 and closed at one end is formed.

Thereafter, as shown by a broken line EE in FIG. 7B, the inner surface of the inclined portion 27 is cut along a plane perpendicular to the central axis C at a position where the inner surface of the inclined portion 27 intersects the central axis C of the cylindrical portion 26. Cut off the edge. Thereby, as shown in FIG.7 (c), the radial direction blade part 23 extended in a radial direction from the center of the cylindrical part 26 is formed in a cut surface.
Further, as shown in FIG. 7 (d), by cutting or grinding the outer peripheral edge of the arc-shaped portion formed on the cut surface over approximately ¾ of the circumference so as to taper toward the tip, A directional blade 22 is formed.
Thereby, the observation surface cutter 20 of FIG. 5 is manufactured.

  In order to form a hole in the living tissue A by the observation surface cutter 20 manufactured as described above, the tip on which the radial blade portion 23 and the circumferential blade portion 22 are formed is pressed against the surface of the living tissue A. Then, the radial blade portion 23 is rotated around the central axis C so as to be directed forward in the rotation direction. As a result, while forming an annular cut by the circumferential blade portion 22, the biological tissue A inside the circumferential blade portion 22 is helically cut by the radial blade portion 23, and the distal end of the observation surface cutter 20 is moved. It can be advanced into the living tissue A. Then, after proceeding to the predetermined depth, the bottom surface has an observation surface D cut flat by the radial blade portion 23 by stopping pressing in the axial direction and continuing to rotate in the same direction on the spot. The hole B can be easily formed.

In addition, in the observation surface cutter 20 according to the present embodiment, after the radial blade portion 23 and the circumferential blade portion 22 are formed by cutting or grinding, each of them is subjected to etching such as wet etching or dry etching. The blade portions 22 and 23 may be formed sharply to improve the sharpness.
Further, each blade portion may be coated with a coating made of a material having a hardness higher than that of the plating material, for example, a diamond coating.

  Further, as the mold 24, one having the inclined surface 24a on one side of the plane P including the axis C is employed, but instead, on both sides of the plane P including the axis C, as shown in FIG. You may employ | adopt the metal mold | die which has the inclined surfaces 24a and 24b which incline in a reverse direction. By doing in this way, as shown in FIG. 9, two radial blade portions 23 extending radially outward from the center and two arc-shaped circumferential blade portions 22 corresponding to ¼ circumference are provided. The observation surface cutter 20 'can be manufactured.

Next, an observation drilling tool 30 according to an embodiment of the present invention will be described below with reference to FIGS.
The observation hole drilling tool 30 according to the present embodiment has, for example, the observation surface cutter according to the first embodiment, but instead of this, the observation surface cutter according to the second embodiment is used. You may have.

  As shown in FIG. 10, the observation hole drilling tool according to the present embodiment is inserted into and removed from a cylindrical guide member 32 having an annular cutting edge 31 at the tip thereof, and an inner side of the guide member 32. The observation surface cutter 1 is fitted so as to be capable of being rotatably supported by the guide member 32 in the circumferential direction, and a positioning mechanism 33 for positioning the axial position of the guide member 32 is provided.

  The guide member 32 includes a substantially cylindrical main body 34, a front end 35 that is detachably attached to the front end of the main body 34, and a push screw (fixing means) 36 that fixes these so as not to rotate relative to each other in the circumferential direction. And. On the outer peripheral surface of the main body portion 34, a step portion 37 is formed over the entire circumference so as to become thinner by one step toward the tip side to which the tip portion 35 is attached.

  The positioning mechanism 33 includes a support member 38 that receives the guide member 32 and an XYZ drive mechanism 39 that moves the support member 38 in the XYZ three-dimensional direction. The XYZ drive mechanism 39 is attached to a support column 41 extending vertically upward from a stage 42 on which a sample X such as an animal is placed, and can position the support member 38 at an arbitrary position.

  The support member 38 includes a through hole 40 in which the guide member 32 is rotatably fitted, and an abutting surface 41 against which the stepped portion 37 of the guide member 32 abuts. By inserting the guide member 32 into the through hole 40 of the support member 38 and abutting the stepped portion 37 against the abutting surface 41, the cutting edge 31 at the tip of the guide member 32 can be accurately positioned in the axis C direction. It is like that.

  For example, in order to open an observation hole B in the deep part of the brain of an animal using the observation drilling tool 30 according to the present embodiment configured as described above, the positioning mechanism 33 is operated and a known tool is operated. The support member 38 is arranged at the position of the hole G drilled in the skull F by the above, and the guide member 32 is fitted into the through hole 40 of the support member 38 so that the cutting edge 31 at the distal end of the guide member 32 is inserted into the skull F. It is brought into contact with the surface of the internal brain tissue A ′. Since the cutting edge 31 of the distal end portion 35 of the guide member 32 is formed in a sharp annular shape, the guide member 32 is axially pressed against the support member 38 or rotated around the axis C. Thus, an annular cut is formed from the surface of the brain tissue A ′ by the cutting blade 31.

  By positioning the support member 38 at a predetermined position, when the stepped portion 37 of the guide member 32 is inserted until it abuts against the abutment surface 41 of the support member 38, further insertion of the guide member 32 is prohibited. As shown in FIG. 5, the cutting edge 31 at the tip of the guide member 32 can be accurately placed at a desired depth position in the brain tissue A ′.

  In this state, the observation surface cutter 1 is inserted inside the guide member 32 as shown in FIG. 12, and the brain tissue is rotated while the observation surface cutter 1 is rotated about the axis C as shown in FIG. By pushing into A ′, the circumferential blade 2 and the wire 5 at the tip of the observation surface cutter 1 are arranged at the same position as the cutting blade 31 at the tip of the guide member 32. At this position, the brain tissue A ′ inside the guide member 32 can be cut along a plane perpendicular to the axis C by rotating the observation surface cutter 1 at least half a circumference around the axis C.

Thereafter, as shown in FIG. 14, by pulling out the observation surface cutter 1 in the direction of the axis C, the cut brain tissue A ′ can be removed while being held at the distal end portion 35 of the observation surface cutter 1. A substantially cylindrical hole B having a flat observation surface D as a bottom surface can be formed in the brain tissue A ′.
In the present embodiment, as shown in FIG. 15, the distal end portion of the guide member 32 is bonded to the skull F with an adhesive H, and the body screw 34 is separated from the distal end portion 35 by loosening the push screw 36. As shown in FIG. 16, the positioning mechanism 33 is operated to raise the main body 34 together with the support member 38, so that the distal end 35 can be placed in a state where the distal end 35 is adhered to the hole G of the skull F.

  Thereby, the distal end portion 35 can function as a hemostatic member, and blood and body fluid from the brain tissue A ′ outside the distal end portion 35 can be prevented from flowing into the observation surface D inside the distal end portion 35. In this state, the inside of the tip 35 is washed with physiological saline or the like. Then, as shown in FIG. 17, the small-diameter tip 44 of the objective lens 43 is inserted into the hole B formed inside the tip 35 and the tip is opposed to the observation surface D. Thereby, the deep part of the brain tissue A ′ can be optically observed two-dimensionally or three-dimensionally.

In the present embodiment, first, an annular cut is formed in the brain tissue A ′ by the guide member 32, and then the inside of the cut is cut by the observation surface cutter 1. And the observation surface cutter 1 may be fixed integrally and cut at the same time.
In the present embodiment, the sample X such as an animal is not fixed, but is fixed by a known fixing device, for example, a stereotaxic fixing device SR-5M manufactured by Narimo Scientific Instruments Research Laboratory, You may decide to improve the arrangement | positioning and observation precision of a guide member more.

It is a longitudinal cross-sectional view which shows the cutter for observation surfaces which concerns on the 1st Embodiment of this invention. It is a partial perspective view which shows the circumferential direction blade part and radial direction blade part of the front-end | tip of the cutter for observation surfaces of FIG. It is a figure explaining the operation | work which forms the hole which has a flat observation surface in a biological tissue using the observation surface cutter of FIG. It is a longitudinal cross-sectional view which shows the modification of the cutter for observation surfaces of FIG. It is a partial perspective view which shows the front-end | tip part of the cutter for observation surfaces which concerns on the 2nd Embodiment of this invention. FIG. 6 is a partial perspective view showing a structure of a tip portion of a mold used for manufacturing the observation surface cutter of FIG. 5. It is process drawing explaining the manufacturing method of the cutter for observation surfaces of FIG. FIG. 6 is a partial perspective view showing a structure of a tip portion of a mold used for manufacturing a modification of the observation surface cutter of FIG. 5. It is a partial perspective view which shows the front-end | tip part of the cutter for observation surfaces which concerns on the modification of FIG. 5 manufactured using the metal mold | die of FIG. It is a whole block diagram which shows the drilling tool for observation which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view explaining the operation | work which forms a hole in brain tissue using the drilling tool for observation of FIG. FIG. 12 is a longitudinal sectional view for explaining an operation of inserting the observation surface cutter into the guide member in which the cut is formed in the brain tissue according to FIG. 11. It is a longitudinal cross-sectional view explaining the operation | work which cut | disconnects a brain tissue with the cutter for observation surfaces inserted by FIG. It is a longitudinal cross-sectional view explaining the operation | work which removes a part of brain tissue cut | disconnected by FIG. It is a longitudinal cross-sectional view explaining the operation | work which adhere | attaches the front-end | tip part of a guide member, after removing a part of brain tissue by FIG. It is a longitudinal cross-sectional view explaining the operation | work which cut | disconnects the front-end | tip part adhere | attached on the skull from the main-body part by FIG. It is a longitudinal cross-sectional view explaining the optical observation performed by inserting the small diameter front-end | tip part of an objective lens in the hole formed in the main-body part cut away by FIG.

Explanation of symbols

A biological tissue A 'brain tissue (biological tissue)
B hole C axis D observation plane P plane 1, 20, 20 'cutter for observation plane 2,22 circumferential blade 3 cutter body (cylindrical body)
4 Notch 5 Wire (radial blade)
6 Tension adjustment mechanism 23 Radial direction blade part 24 Mold (mold member)
24a, 24b Slope 25 Plating layer (metal film)
27 Inclined portion 28 Cylindrical material 30 Observation drilling tool 31 Cutting blade 32 Guide member 34 Main body portion 35 Tip portion 36 Press screw (fixing means)
37 Step 38 Support member 41 Abutting surface

Claims (4)

An observation surface cutter for forming a substantially cylindrical hole having a flat observation surface on a bottom surface of a living tissue,
The tip of the cylindrical body, provided with a circumferential edge portion extending in a circumferential direction, the radial blade section extending radially from a center of at least the cylindrical body, and a tension adjusting mechanism for adjusting the tension of said wire, said radial blades Department has a viewing surface for the cutter ing from wires stretched in the circumferential direction cutting section,
A cylindrical guide member having an annular cutting edge over the entire circumference at the tip,
An observation hole drilling tool in which the observation surface cutter is removably fitted inside the guide member and is rotatably supported by the guide member in a circumferential direction. The circumferential blade portion is provided with a notch at an interval of 180 ° in the circumferential direction,
Observation drilling tool according to claim 1, wherein the wire notch is engaged. On the outer peripheral surface of the guide member, a stepped portion that tapers toward the tip is provided,
While rotatably supporting the guide member, the guide provided with the stepped portion abutting against the abutting surface axially of the member, and a supporting member provided so positionable in the axial direction of the guide member according to claim 1 or The observation hole punch according to claim 2 . The guide member includes a main body having the stepped portion, a tip having an annular cutting blade attached to the main body so as to be detachable in the axial direction, and the tip and the main body in the circumferential direction. The observation hole drilling device according to claim 3 , further comprising fixing means for fixing so as not to relatively rotate.

Images