JPS6132651Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a skull fixation adapter plug for fixing a medical device such as an intracranial pressure measuring device to the skull.

When measuring the internal pressure inside the skull without damaging the dura mater under the skull, a skull fixation adapter plug is used to fix the pressure measurement sensor of the brain pressure meter to the skull.

FIG. 1 represents the conventional structure of such an adapter plug. Reference numeral 1 designates an adapter plug made of stainless steel or the like, which extends from its upper end surface 2 to its lower end surface 3.
A screw 5 is formed in the outer circumferential wall 4 which is tapered toward the outer peripheral wall 4, and a through hole 6 is formed in the inner side approximately at the center.

When measuring intracerebral pressure, cut a hole into the patient's skull.
A hole is made using a reamer or the like so that the central axis is as perpendicular to the center point of the head as possible. Next, since the thickness of the skull differs depending on the patient, the thickness of the skull is measured, and an adapter plug 1 having a thickness matching the measured thickness is selected. The selected adapter plug 1 is positioned corresponding to the hole using a special tool, rotated, and screwed into the skull. FIG. 2 shows the installed state.

By the way, when measuring intracerebral pressure, an elastic, flat pressure-receiving membrane (not shown) is pressed onto the dura mater 8 that surrounds the ventricles of the brain beneath the skull 7, and the pressing force of the pressure-receiving membrane is measured. and the tension of the dura mater 8 are balanced, and the pressure at the time of balance is measured. Therefore, it is desirable that the dura mater 8 be uniformly flat at the measurement location as well as under the skull 7.

Therefore, the lower end surface 3 of the adapter plug 1 is formed so as to be able to press the dura mater 8 flatly (the lower end surfaces 3 of the inner wall 6A forming the through hole 6 and the outer peripheral wall 5).
The adapter plug 1 needs to be attached so that the lower end surface 3 is approximately flush with the inner plate 9 of the skull 7 (the distance (thickness) in the vicinity is approximately 2 mm). The adapter plug 1 is rotated and screwed in while checking visually from the through hole 6 whether the lower end surface 3 is located on the same plane as the inner plate 9. The thickness is relatively thick and the pressure inside the ventricle is 0~
Since the temperature is about 50 mmHg, when a hole is made in the skull 7, the dura mater 8 bulges outward in a spherical shape (see Figure 2), so this confirmation is extremely difficult and requires skill.

The present invention was developed in view of the above situation, and an object of the present invention is to provide an adapter plug with which it can be easily confirmed that the lower end surface is located substantially on the same plane as the inner plate of the skull.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In these figures, parts corresponding to those in FIGS. 1 and 2 are given the same numbers, and detailed description thereof will be omitted. The difference between the adapter plug 1 according to the present invention and the conventional one shown in FIGS. 1 and 2 is that the distance (thickness) between the outer peripheral wall 4 and the inner wall 6A of the through hole 6 in the vicinity of the lower end surface 3 is At least one groove 10 (in the embodiment, two grooves 10 are formed so that the thickness is smaller than that in other parts
(individuals) were formed. In other words, the adapter plug 1 has a relatively large wall thickness in the vicinity of the lower end surface 3 where the groove 10 is not formed (corresponding to the width of the lower end surface 3); In the portion where the outer peripheral wall 4 and the inner wall 6A are formed, the outer peripheral wall 4 and the inner wall 6A do not constitute the lower end surface 3 but directly intersect with each other (the wall thickness is almost zero). The thickness of the portion where the groove 10 is formed may be constant from the lower end surface 3 to the upper end surface 2, but if it is formed so as to gradually increase as in the embodiment. , sufficient strength can be obtained. Further, since the groove 10 is provided only in a part, there is less risk of accidentally damaging the dura mater 8 when the lower end face 3 is screwed in, as in the case where the entire lower end face 3 is formed thin with an acute angle. Although the groove 10 has a substantially circular cross section in the embodiment, it goes without saying that it may have a rectangular or other shape.

The state in which such an adapter plug 1 is attached to the skull 7 is shown in FIG. As is clear from this figure, since the groove 10 is formed relatively small, the bulge of the dura mater there is relatively small. If the screwing is stopped at a position where the side surface of the hole in the skull 7 is no longer visible, this will be the position where the lower end surface 3 reaches approximately the same plane as the inner plate 9 of the skull 7.

As described above, in the present invention, it is possible to safely and easily confirm that the lower end surface of the adapter plug has reached substantially the same plane as the inner plate of the skull, and it is possible to accurately measure intracerebral pressure.

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional view of a conventional adapter plug.
Figure 2 is an explanatory diagram showing how it is installed, Figure 3a
FIG. 4 is a partial sectional view of the adapter plug according to the present invention, FIG. 4B is a bottom view thereof, and FIG. 1...Adapter plug, 2...Top end surface, 3...
... lower end surface, 4 ... outer peripheral wall, 5 ... screw, 6 ...
Through hole, 6A...Inner wall, 7...Cranium, 8...Dura mater, 9...Inner plate, 10...Sulcus.

Claims (1)

[Scope of utility model registration request] A skull fixing adapter plug for fixing a medical device such as an intracranial pressure measuring device to the skull, which has an outer circumferential wall formed in a tapered shape, a screw formed on the outer circumferential wall, and a screw formed approximately at the center. A through hole, a lower end surface formed flat between an inner wall of the through hole and an outer circumferential wall, and a wall thickness formed by the outer circumferential wall and the inner wall in the vicinity of the lower end surface. An adapter plug for fixing a skull, characterized by having a groove formed to have a width smaller than the width of the adapter plug.