JP2016077356A - Skull fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easier to attach a fixing tool for fixing a skull and minimize the burden on the skull.SOLUTION: A fixing tool for fixing a skull includes: skull side fixing tools 2-1 to 2-3; a C-shaped frame 1 extending along the outer periphery of a skull; a fixing bolt 3 having an end portion engaged with the skull side fixing tools; a fixing bolt holding part 4 for connecting the fixing bolt 3 to the C-shaped frame 1. A slit is formed in the C-shaped frame 1 in the circumferential direction and allows the fixing bolt holding part 4 to be turned and adjusted within a predetermined angle range in the radial direction of the C-shaped frame 1. A spherical bearing is formed between the end portion of the fixing bolt 3 and the bottom surface of a cylindrical part provided on the skull side fixing tools 2-1 to 2-3.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a skull fixing device, and more particularly, to a skull fixing device for clamping a head so that it does not move during an experiment using a laboratory animal such as a monkey. .

Generally, Patent Literature 1 is known as a head fixing device for brain surgery. In such a head fixing device, bolts are screwed to both ends of the C-shaped frame so as to face the skull, and each bolt is screwed to fix the opposite surface of the skull with a pin at the tip, and the C-shaped frame Is fixed to the operating table.
However, in the case of an experimental animal that conducts experiments in a conscious state, such a fixing device cannot reliably fix the skull, making the experiment impossible, and damaging the experimental animal. End up.
Further, in the case of a laboratory animal, since experiments are repeatedly performed on one animal over a long period of time, a great deal of labor is required for the skull fixing work each time.

Therefore, for example, in the case of a laboratory animal such as a monkey, as shown in Non-Patent Document 1, when a fixture is embedded in a predetermined position of the head and this experiment is performed, Secure to a fixed point around the laboratory, such as a chair.
As such a fixture, for example, a fixture provided with a bolt receiving portion is embedded at three points along the periphery of the skull, and the tip of the bolt attached to the C-shaped frame is screwed into the bolt receiving portion of this fixing device. A frame is fixed, or a radially extending leg is screwed to the skull and fixed with a central protrusion.
By fixing the fixing device embedded in the head in this way to fixed points around the laboratory, various experiments were conducted after fixing the head, and after the experiment was completed, the fixing device was removed from the fixing point. Return the experimental animal to the cage with the fixture in place.

JP-T-2004-530471

NIH Public Access (J Neurosci Methods, issued June 30, 2009)

In the skull fixing device as shown in Non-Patent Document 1, the three bolts attached to the C-shaped frame are fixed by aligning the tip ends of the bolts with the bolt receiving portions of the fixture.
However, the conventional apparatus does not have a degree of freedom in the bolt tip position with respect to the embedded fixture. For this reason, when the fixture is embedded in the experimental animal, it is very difficult to mount the bolt unless the position of each bolt receiving portion is accurately matched with the bolt position of the C-shaped frame.
In addition, as the number of places where fixtures are embedded increases, the load per point can be reduced and the burden on experimental animals can be reduced. However, if there are four or more fixtures, the positions of the bolt receiving portions are exactly the same. It must be arranged on a plane, and it is very difficult to make the fixing tool embedded at four or more places.

However, because there are cases where experimental animals are exposed, the fixing tool must be firmly fixed to the skull, and the bolt used to screw the fixing tool must be large and thick. Giving a big burden.
Therefore, the present invention significantly increases the degree of freedom when fixing the C-shaped frame with screws, reduces the operation for attaching the fixture to the maximum, and suppresses the burden on the skull to a minimum. It is aimed.

  In order to solve the above-described problems, a fixing device of the present invention is a fixing device for fixing a skull, and includes a skull-side fixing device mounted at a predetermined interval along a circumferential direction of the skull, and an outer periphery of the skull. A C-shaped frame, a fixing bolt having a distal end portion that engages with the skull-side fixing tool, and a fixing bolt holding portion that connects the fixing bolt to the C-shaped frame. A slit is formed in the letter-shaped frame along the circumferential direction, and is fixed to the slit at two points via bolt insertion holes formed at both ends in the circumferential direction of the fixing bolt holding portion. The fixing position of the fixing bolt can be adjusted in the circumferential direction along the slit, and one of the bolt insertion holes formed at both ends in the circumferential direction of the fixing bolt holding portion is connected to the C-shaped frame. No lap By making the slit in a direction orthogonal to the direction, the fixing position of the fixing bolt can be adjusted in a predetermined angular range with respect to the radial direction of the C-shaped frame, and the tip of the fixing bolt A spherical bearing was formed between the portion and the bottom surface of the cylindrical portion provided on the skull side fixture.

  According to the present invention, the fixing position of the fixing bolt can be adjusted not only in the circumferential direction of the C-shaped frame but also in a predetermined angle range with respect to the radial direction. Therefore, it is possible to reduce the burden on experimental animals.

FIG. 1 is a diagram showing a C-shaped frame. FIG. 2 is a view showing a skull side fixing tool. FIG. 3 is a diagram illustrating a connection state of the skull side fixing tool and the fixing bolt. FIG. 4 is a view showing a state in which the fixing bolt is mounted by the fixing bolt holder along the circumferential direction of the C-shaped frame 1.

  Hereinafter, examples will be described with reference to the drawings.

The main parts of the skull fixing device of the present embodiment include a C-shaped frame 1, a skull side fixing tool 2, and a fixing bolt holder 4.
FIG. 1 shows a C-shaped frame 1, in which the left side is a plan view and the right side is a side view. The C-shaped frame 1 is made of an aluminum alloy or the like, and has an inner diameter larger than the outer periphery of the head of the experimental animal to be mounted. In FIG. 1, the right arc portion protrudes in the circumferential direction from the left side, and the right arc portion has a first slit 1 a extending in the circumferential direction from the end portion and spaced from the first slit 1 a in the circumferential direction. A second slit 1c extending near the fixed portion 1b formed at the lower end is formed. Also, bolt holes 1d and 1e are formed at the left arc portion end. A plurality of bolt holes are formed in the fixing portion 1b, and by using these bolt holes, the C-shaped frame 1 can be fixed to an experimental facility, and other instruments necessary for experiments can be mounted. Yes.

2A and 2B show the structure of the skull-side fixing device 2, wherein FIG. 2A is a front view, FIG. 2B is a plan view, and FIG. 2C is a side view.
The skull-side fixture 2 is directly attached to the skull of a laboratory animal, and is preferably formed of titanium or a titanium alloy in consideration of the affinity for the skull including the tap screw described later.
A cylindrical portion 2a is formed in the center of the skull side fixing tool 2, and a bearing groove 2b shown in FIG. 3 can be mounted using a screw groove formed on the inner periphery thereof.
The bearing component 2b is processed into a conical concave surface so that a spherical bearing is formed between the bearing component 2b and a hemispherical portion 3a provided at the tip of a fixing bolt 3 to be described later.

On the bottom surface of the cylindrical portion 2a, a hole 2i for inserting a tap screw that is embedded in the skull of the experimental animal is formed. The shape of the tap screw insertion hole 2i is selected so as not to interfere with the bearing component 2b when the tap screw is inserted.
A spherical bearing may be integrally formed on the side surface of the cylindrical portion 2a, and the tap screw insertion hole 2i may be provided individually.

On the other hand, on the bottom surface of the cylindrical portion 2a, legs 2f to 2h having holes 2c to 2e for inserting tap screws are integrally formed above (in the direction of the top of the skull) and left and right (in the circumferential direction of the skull) in FIG. Is formed.
That is, as shown in FIG. 3, when the fixing bolt 3 is pushed into the bearing component 2b, the leg portions 2f to 2h are loaded on the skull through the hole 2i for inserting the tap screw. It arrange | positions in the position which distributes the stress which carries out. As a result, by embedding the four tap screws 2j to 2m in the holes 2i and 2c to 2e for inserting the tap screws, respectively, the burden on the skull is minimized, and the skull side fixing device 2 is firmly attached. be able to.
In order to firmly fix the skull side fixing tool 2 to the skull, it is desirable that the bottom surface portion thereof is as close as possible to the skull surface. Therefore, the bottom surface of the cylindrical portion 2a is molded into a curved surface close to the skull, and the leg portions 2f to 2h are provided with grooves so that they can be easily bent along the surface of the skull. An effect of promoting adhesion to bone tissue is also expected when the skull-side fixing device 2 made of titanium is in close contact with the skull.

Next, attachment of the fixing bolt 3 to the C-shaped frame 1 will be described.
FIG. 4 shows a state in which three fixing bolts 3-1 to 3-3 are attached by fixing bolt holders 4-1 to 4-3 along the circumferential direction of the C-shaped frame 1. Yes.
A fixing bolt holder 4-1 having a thread groove into which the fixing bolt 3-1 is screwed is formed on the lower surface on the left end side of the C-shaped frame 1, and the bolt is formed on the left end side of the C-shaped frame 1. It is fixed by two bolts 6a and 6b inserted through the holes 1d and 1e and 5a and 5b formed in the fixing bolt holder 4-1. The bolt insertion hole 5b formed in the fixing bolt holder 4-1 that is aligned with the lower insertion hole 1e is an arc-shaped slit, and the fixing angle of the fixing bolt 3-1 is set to the upper side. Rotation adjustment can be made within a range of ± 10 ° around the bolt insertion hole 5a.

As a result, the fixing bolt 3-1 is screwed into the screw groove of the fixing bolt holder 4-1, and the tip thereof is aligned with the inside of the fixing bolt tip receiving portion of the skull side fixing tool 2-1. The bolts 6a and 6b inserted into the bolt insertion holes 5a and 5b can be fastened and fixed. Reference numeral 7 denotes a nut for preventing the fixing bolt 3-1 from loosening.
In this embodiment, the distal end portion of the fixing bolt 3-1 is made to enter a receiving hole formed in the side wall of the cylindrical portion of the skull side fixing tool 2-1.

On the lower surface on the right end side of the C-shaped frame 1, a fixing bolt holder 4-2 having a bolt hole into which the fixing bolt 3-2 is screwed is formed in an arc shape formed on the upper surface of the C-shaped frame 1. It is fixed by two bolts 6c and 6d inserted from the first slit 1a. The upper bolt 6c is screwed into the fixing bolt holder 4-2 itself. The lower bolt 6d is passed through an arc-shaped bolt insertion hole 5d formed in a direction orthogonal to the circumferential direction of the C-shaped frame 1 formed in the fixing bolt holder 4-2, and the nut 8 By fixing, the fixing angle of the fixing bolt 3-2 can be adjusted in a range of ± 10 ° with respect to the radial direction of the C-shaped frame 1 around the upper bolt 6c.
As a result, the fixing bolt 3-2 can be positioned and adjusted within a range of ± 10 ° around the circumferential direction of the C-shaped frame 1 and the upper bolt 6c in addition to the length direction.
The mounting structure of the fixing bolt 3-3 using the fixing bolt holder 4-3 also includes an arc-shaped bolt insertion hole 5f and adopts the same structure as the mounting structure of the fixing bolt 3-2. Note that the fixing bolt connectors 4-1 to 4-3 and the like are preferably lightweight and high-strength, and are formed of pure titanium in this embodiment.

When fixing the C-shaped frame to the skull, perform the following procedure: Determine the attachment position of the skull-side fixture 2 along the periphery of the skull, taking into account the joints of the skull bones, etc. Screw onto the skull with tap screws.
For example, when attaching the skull side fixing tool to three locations of the skull, it is preferable that the fixing bolt 3 meshes perpendicularly with the bearing portion in order to strengthen the fixing. However, in the present invention, as described above, in particular, the fixing bolt 3-2 and 3-3 are added to the length direction, swiveling in the circumferential direction of the C-shaped frame 1 and further in the radial direction of the C-shaped frame 1 around the upper bolt insertion holes 5c and 5e. Since the positioning can be adjusted by making it possible, it is not necessary to precisely position the skull side fixing device when the head is mounted on the skull. Furthermore, since the bearing portion is a spherical bearing, it is not necessary to place the skull side fixing tool along the horizontal plane, and it is relatively easy to use four or more.

  Next, the fixing bolt holder 4-1 on the left end side in FIG. 4 is temporarily fixed. That is, after the bolt insertion holes 5a and 5b formed in the fixing bolt holder 4-1 are aligned with the two bolt insertion holes 1d and 1e of the C-shaped frame, the bolts 6a and 6b are respectively inserted. To do. The bolt 6a inserted into the upper bolt insertion hole 5a is fixed to the screw hole of the fixing bolt holder 4-1, and the bolt 6b inserted into the lower bolt insertion hole 5b is fixed to the lower surface with a nut.

  Fixing bolts are screwed into the respective fixing bolt holders, and the fixing bolt holders 4-2, 4- are fitted so that the tips of the fixing bolts fit into the recesses of the skull side fixing tool attached in Step 1 (see paragraph [0020]). 3 is slid in the arc-shaped first slit 1a and second slit 1c, and the position is adjusted so as to match the skull-side fixture 2 corresponding thereto. At that time, as shown in FIG. 4, the bolts 6c and 6e inserted into the upper bolt insertion holes 5c and 5e are turned around using the arc-shaped bolt insertion holes 8 formed in the skull side fixing tool 2, and C Angle adjustment in a direction (radial direction) orthogonal to the circumferential direction of the letter-shaped frame is performed.

  While tightening the fixing bolts 3-2 and 3-3 in sequence, the position is finely adjusted along the two arc-shaped slits, and when the tightening torque of the fixing bolts 3-2 and 3-3 reaches a predetermined position, All bolts 5 are tightened to complete the mounting.

  As described above, since each fixing bolt has a degree of freedom in two directions, even if the position of embedding the skull side fixing device is slightly shifted, even if the skull side fixing device is attached to four or more points, Appropriate tightening is possible. Since the skull side fixing tool is fixed with four tap screws, even if the tap screw hole is made small, it can be fixed securely.

1 C-shaped frame 2 Skull side fixture 3 Fixing bolt 4 Fixing bolt holder

Claims (2)

A fixture to fix the skull,
A skull-side fixing device mounted at a predetermined interval along the circumferential direction of the skull;
A C-shaped frame along the outer periphery of the skull;
A fixing bolt having a tip portion engaged with the skull side fixing tool;
A fixing bolt holding part for connecting the fixing bolt to the C-shaped frame;
The C-shaped frame has slits along the circumferential direction, and is fixed to the slit at two points via bolt insertion holes formed at both ends of the fixing bolt holding portion in the circumferential direction. The fixing position of the fixing bolt can be adjusted in the circumferential direction along the slit, and
By fixing one of the bolt insertion holes formed at both circumferential ends of the fixing bolt holding portion as a slit in a direction perpendicular to the circumferential direction of the C-shaped frame, the fixing position of the fixing bolt is With respect to the radial direction of the C-shaped frame, turning adjustment is possible within a predetermined angle range,
A fixing device, wherein a spherical bearing is formed between a distal end portion of the fixing bolt and a bearing component attached to a cylindrical portion provided in the skull side fixing device. The skull-side fixture includes a cylindrical portion, a leg portion extending from the bottom surface of the cylindrical portion, and a tap screw for inserting a tap screw to be embedded in the skull into the bottom surface of the cylindrical portion and the end portion of the leg portion. The fixing tool according to claim 1, wherein an insertion hole is formed.

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