JPH01175833A - Cranium internal pressure measuring device - Google Patents

Abstract

PURPOSE:To facilitate the measurement of cranium internal pressure by providing an air pressure measuring section communicating to an air chamber for measuring the air pressure in the air chamber and a pressure indicator connected said measuring section for indicating the air pressure in the air chamber. CONSTITUTION:A brain chamber shunt A for measuring the cranium internal pressure is embedded in a predetermined position, and the flow of marrow liquid from a brain chamber catheter 2 to an abdominal cavity catheter 3 is interrupted by closing a cut-off valve mechanism V in a shunt body 1. While the marrow liquid is introduced through a brain chamber catheter 2 into a cranium internal pressure measuring reservoir 11 embedded under the head skin and on the skull 17, the upper dome 11a of reservoir 11 is developed to protrude outward by the pressure of said marrow liquid. An air chamber B is fixed to the head skin 16 so that a flexible diaphragm 27 of an air chamber B reaches the upper dome 11a of reservoir 11. An air pump 104 is operated to send air into the air chamber B through a supply pipe 105 and pressurize the interior of air chamber B with proper pressure. A pressure value when pressure in the air chamber B indicated on an indicator 102 becomes constant is the measured pressure value.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an intracranial pressure measuring device, and particularly to an intracranial pressure measuring device for measuring the intracranial pressure of a patient suffering from hydrocephalus, etc. The ventricular shunt used for intracranial pressure measurement functions as a ventricular-peritoneal shunt or a ventricular-atrial shunt (hereinafter referred to as "ventricular shunt") that is surgically implanted into the body of a patient suffering from hydrocephalus, etc. Concerning things that have both.

[Conventional technology]

Generally, in neurosurgical diseases accompanied by increased intracranial pressure,
Accurate measurement of intracranial pressure is necessary to elucidate these pathological conditions.

Conventionally, various methods for measuring intracranial pressure have been proposed, including Surg, Neuro 1. .

Volll, April 1979, proposes a "remote pressure sensor for ventricular shunt systems."

This remote pressure sensor for ventricular shunt system is provided with a ventricular shunt 50 and a pressure detection device 60, as shown in FIGS.
is a tubular ventricular catheter 51 inserted into the ventricle.
and a shunt main body (relay chamber) 52 connected to this ventricular catheter 51 and composed of a reservoir and a pump chamber,
The shunt main body 52 is connected to a tubular peritoneal catheter or an atrial catheter 53 that is inserted into the abdominal cavity or atrium.

The shunt main body 52 is buried on the skull 17 under the scalp 16, and the shunt main body 52 includes a miter valve or the like that can be pushed open by the pressure of cerebrospinal fluid, which is fluid discharged from the ventricles. A relief valve 54 is provided.

Furthermore, the shunt main body 52 includes a flexible diaphragm 55 formed in the upper part of the flow path and capable of expanding upward in response to the pressure of the cerebrospinal fluid flowing in the flow path, and a flexible diaphragm 55 formed in the lower part of the flow path. A diaphragm stopper 56 is provided to face the flexible diaphragm 55, and a pressure detection device 6 is provided in the flow path of the shunt body 52.
An embedded pressure sensor 57 forming a part of the diaphragm 0 is inserted, and this embedded pressure sensor 57 is embedded in the shunt body 52 forming the diaphragm stopper 56 and has a resonant circuit such as a coil. It is composed of a tuning circuit 58 and a tuning element 59 attached to the flow path side of the flexible diaphragm 55 and changing the resonance frequency of the tuning circuit 58 according to the distance between the tuning circuit 58 and the tuning circuit 58.

The pressure detection device 60 includes the above-mentioned embedded pressure sensor 57 embedded within the patient's body, and the following members provided outside the patient's body.

That is, outside the body, there is an antenna 61 that sends electromagnetic waves to the pressure sensor 57 in order to detect the resonant frequency in the pressure sensor 57, and an electronic device 62 that receives a change in the signal sent to the antenna 61 and indicates that it is at the resonant frequency. By pressing the above-mentioned flexible diaphragm 55 through the scalp 16, the embedded pressure sensor 5
A non-metallic pressurizing body 63 that is inflated by air pressure in order to bring the tuning element 59 of No. 7 closer to the tuning circuit 58 is attached to the scalp 1.
6 and the antenna 61, and a compressed air supply device 64 that supplies compressed air to the pressurizing body 63, and a pressure sensor that detects the pressure of the compressed air supplied from the compressed air supply device 64. A total of 65 are provided.

In such a conventional example, intracranial pressure is measured by the following procedure.

<1> The electronic device 62 receives the signal from the antenna 61 by placing the antenna 61 at the detection position, pressing the diaphragm 55 with a finger through the scalp 16, and bringing the tuning circuit 58 and tuning element 59 close together. Calibrate.

(2> In the <+> state, release your finger and release the diaphragm 55.
bulges outward, the tuning circuit 58 and the tuning element 59 are separated, and the signal from the antenna 61 causes the electronic device 62 to
Check that the display moves away from the calibration area.

<3> Insert the pressurizing body 63 between the scalp 16 and the antenna 61 and apply pressure until the display on the electronic device 62 is in the calibration range, and the pressure measured by the pressure gauge 65 at this time is the intracranial pressure. shall be.

[Problem that the invention seeks to solve]

However, in such conventional intracranial pressure measuring means, a resonant circuit consisting of a tuned circuit 58 and a tuned element 59 must be built into the body, and a part that responds to electromagnetic waves etc. is buried inside the body. There are problems in that it interferes with the formation of tomographic images by CT scanners, nuclear magnetic resonance scanners, etc., and the overall structure is complicated, making it difficult to calibrate accurately.

The present invention aims to solve these problems by making it possible to easily handle objects buried in the body using a simple device, and making it possible to easily measure intracranial pressure. The purpose of the present invention is to provide an intracranial pressure measuring device with the following features.

[Means for solving problems]

Therefore, the intracranial pressure measuring device of the present invention includes a ventricular catheter whose distal end can be inserted into the ventricle to draw out cerebrospinal fluid from the ventricle, and a ventricular catheter which is connected to the proximal end of the ventricular catheter. It is equipped with an intracranial pressure measurement reservoir that guides cerebrospinal fluid and is buried under the scalp and on the skull, and in the upper part of the reservoir,
A shunt for measuring intracranial pressure is formed with a flexible curved dome for measuring intracranial pressure that is formed to protrude outward and is expanded by the pressure of the cerebrospinal fluid and can be bent in response to pressure from an external force. an air chamber having a flexible membrane as a wall that can be contacted from the outside through the scalp; an air discharge part having a small opening protruding into the chamber and facing the inner surface of the flexible membrane; an air supply unit that communicates with the air chamber and can supply air at a constant flow rate into the air chamber; an air pressure measurement unit that communicates with the air chamber and can measure the air pressure in the air chamber; The present invention is characterized in that a pressure measuring means is combined with a pressure indicator connected to the measuring section and capable of displaying the air pressure in the air chamber.

[For production]

In the intracranial pressure measurement device of the present invention described above, cerebrospinal fluid is guided from the brain to the intracranial pressure measurement reservoir through the ventricular catheter, and the pressure of this cerebrospinal fluid expands the curved dome of the reservoir. The flexible membrane of the air chamber deforms as it expands, creating a gap between the flexible membrane and the small opening of the air discharge section, through which the air supplied from the air supply section passes through the air discharge section. leaks, and the intracranial pressure and air pressure in the air chamber become balanced,
Intracranial pressure can be measured by measuring the pressure within the air chamber.

〔Example〕

Hereinafter, an intracranial pressure measuring device as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing its measurement state, and FIGS. 2 and 3 are plan views and views showing its air chamber, respectively. A side sectional view, FIG. 4 is a schematic diagram of the measurement system, and FIG. 5 is a cross-sectional view showing the ventricular shunt for intracranial pressure measurement used in this device (cross-sectional view along the v-■ arrow in FIG. 1).
, FIG. 6 is a sectional view taken along the line Vl-Vl in FIG. 5, the seventh factor is a sectional view taken along the line ■-■ in FIG.
■A cross-sectional view taken along the arrows, Figures 8 (b) to (d) are all schematic diagrams for explaining the action during burial, and Figure 9 is a cross-sectional view taken along the line II-IIX of Figure 5. Figure 10 is x- in Figure 5
11 is a plan view showing an enlarged view of the section ■ in FIG. 5; FIG. 12.13 is a schematic perspective view and side view for explaining the measurement principle; FIG. 14.15 The figure is a schematic cross-sectional view for explaining changes depending on the pressure state of the air chamber.

As shown in FIG. 1, an intracranial pressure measuring device as an embodiment of the present invention includes a shunt A for measuring intracranial pressure that is implanted inside the body of a patient, and a shunt A for measuring intracranial pressure that is placed outside the patient's body. Scalp 16 to reservoir 11 for intracranial pressure measurement of shunt A
It consists of an air chamber B as a pressure detection device that can be contacted via the air chamber B.

The intracranial pressure measurement shank 1-A is connected to a tubular ventricular catheter 2 whose tip end 2b can be inserted into a patient's ventricle 19 to drain cerebrospinal fluid from the ventricle 19, and the catheter 2. The skull 17 is equipped with a reservoir 11 and a skull 16 below the scalp 16.
The shunt body 1 is made of a soft wall made of silicone resin or the like fixed thereon, and a thin film-like flexible curved dome lla for intracranial pressure measurement is formed above the reservoir 11.

A flexible membrane 27 is provided on the wall of the air chamber B.

Furthermore, in the air chamber B, as shown in FIGS. 2 to 4,
An air exhaust port 25 having a small opening 26 is provided so as to face the inner surface of the flexible membrane 27 .

When the external pressure acting on the outer surface of the flexible membrane 27 (in this case, the pressure due to the force of the scalp 16 pushing the flexible membrane 27) and the internal pressure acting on the inner surface of the flexible membrane 27 (pressure inside the air chamber) are equally balanced. In order for the flexible membrane 27 to close the small opening 26, the central portion of the flexible membrane 27 has a thickness t.

Furthermore, during the above-mentioned balance, the outer surface (the surface that contacts the scalp 16) of the flexible membrane 27 is a flat surface without any curvature.

The thickness of the outer and inner parts of the flexible membrane 27 is smaller than the thickness t of the central part, and if the internal pressure is even slightly larger than the external pressure acting on the flexible membrane, the small opening 26 and the flexible membrane 27 form a gap, and the air in the air chamber B flows through the small opening 26.
It is opened to the exhaust port 25 through the exhaust port 25 to cause near leakage.

Furthermore, a supply port 24 and a measurement port 23 are provided on the side surface of the air chamber B. The supply port 24 is the supply pipe 1
05 to the air pump 104. The supply pipe 105 is provided with a throttle 103 so that air can be supplied into the air chamber B at a constant flow rate.

The measurement port 23 is connected to the pressure sensor 100 through a pipe 106, so that the pressure inside the air chamber B can be measured.

Further, a pressure amplifier 101 is connected to the pressure sensor 100, and its output can be displayed on a display 102.

To explain the shunt A for intracranial pressure measurement in more detail,
As shown in Fig. 1, in addition to the tubular ventricular catheter 2 that can drain cerebrospinal fluid in the patient's ventricle 19, the shunt A for intracranial pressure measurement has its tip inserted into the patient's abdominal cavity or atrium. A peritoneal catheter or an atrial catheter (hereinafter referred to as a "peritoneal catheter") 3 is provided so that the cerebrospinal fluid can be withdrawn into the abdominal cavity or atrium.

A main passage 10 is provided in the shunt body 11, and the proximal end 2a of the ventricular catheter 2 and the proximal end 3a of the peritoneal catheter 3 are communicated with each other.

Moreover, as shown in FIG. 5, these shunt bodies 1.
The ventricular catheter 2 and the peritoneal catheter 3 are provided with a check valve 4 that can prevent backflow of cerebrospinal fluid from the peritoneal catheter 3 to the ventricular catheter 2. Slit type relief valves 6 and 7 serving as flow rate adjusting sections of the flow rate switching mechanism 5, which will be described later, also serve this function.

As shown in FIG. 11, these slit type relief valves 6.7 are formed integrally with valve seats 8a and 9a, which will be described later, to constitute a member 33 with a relief valve. is sandwiched between the upper part IA and the lower part IB of the shunt main body 1 and is bonded thereto.

That is, the shunt main body 1 is separated into an upper part LA and a lower part IB at the hatched part in FIG. 5, and is assembled by adhering them to each other.

The shunt body 1 is attached to the skull 1 under the scalp 16 by suturing the suture or the like passing through the suture through hole 15 to the scalp 16.
a main passage 10 fixed on the ventricular catheter 7 and connected to the above-mentioned ventricular catheter 2 and peritoneal catheter 3; and a small chamber-shaped glue reservoir 11 formed on the ventricular catheter 2 side of the main passage 1O.
, a small chamber 12 formed on the peritoneal catheter 3 side of the main passage 10 , and a first chamber 12 that connects the branch part 10 a in the main passage 10 downstream of the reservoir 11 and the small chamber 12 in parallel with each other.
The flow path 13 and the second flow path 14 are provided.

In the first flow path 13, as shown in FIG.
The first slit 6a is formed with a predetermined depth Dl that can adjust the flow rate in the communicating state of the flow path 13 to a predetermined flow rate Q1.
A slit-type relief valve 6 as a flow rate adjustment part, and a pole-type on-off valve 8 as a first on-off valve capable of blocking this first flow path 13 by receiving a driving force from the outside of the shunt body 1. It is interposed.

The pole type on-off valve 8 includes a circular valve seat 8a formed on the wall surface of the shunt main body 1, a valve chamber 8b formed in a first flow path 13 on the upstream side opposite to the circular valve seat 8a, A soft upper wall 1a and a soft front wall 1b of the valve chamber 8b are sealed in the chamber 8b.
A movable spherical valve body 8c that can be moved by receiving a driving force from a finger 18 or the like from the outside of the scalp 16, and a flexible spherical valve body 8c in a position where the valve body 8c is aligned with the valve seat 8a by seating the valve body 8c. A circular seat (recess) 8d for holding the closed position which is sandwiched between the upper wall 1a and closes the on-off valve 8 and blocks the first flow path 13, and the valve body 8C by seating the valve body 8c.
and a circular seat (recess) 8e for holding the open position, which is held between the soft upper wall 1a at a position apart from the valve seat 8a, and opens the on-off valve 8 and communicates the first flow path 13. .

In the second flow path 14, as shown in FIG.
A predetermined depth D2 (<
A slit-type relief valve 7 as a second flow rate adjustment part formed with a slit 7a of DI) and a second opening/closing valve that can block the second flow path 14 by receiving a driving force from the outside of the shunt body 1. A pole type on-off valve 9 as a valve is inserted.

The pole type on-off valve 9 is formed in a circular valve seat 9a formed on the wall surface of the shunt body I, and a second flow path 14 on the upstream side opposite to the circular valve seat 9a. Valve chamber 9b
and the soft upper wall la and the soft front wall 1 of the valve chamber 9b.
A movable spherical valve body 9c that can be moved by receiving a driving force from a finger 18 or the like from the outside of the scalp 16, and a position where the valve body 9c is aligned with the valve seat 9a by seating the valve body 9C. A circular seat (concave portion) 9d for holding the closed position that is sandwiched between the soft upper wall 1a and the valve body 9c closes the on-off valve 9 and blocks the second flow path 14, and the valve body 9c is seated thereon.
c and a circular seat (recess) 9e for holding the open position, which is held between the soft upper wall 1a at a position apart from the valve seat 9a, and opens the on-off valve 9 and communicates the second flow path 14. The structure is substantially the same as the above-mentioned Paul type on-off valve 8.

The first relief valve 6 has a larger regulated flow rate than the second relief valve 7, and in this embodiment, each relief valve 6,
7 is constructed as a single-slit type check valve, but these may be changed to a cross-slit type, a spring-equipped type, a membrane type, etc.

The movable spherical valve bodies 8c, 9c may be made of plastic or metal, but may also be made of a metal ball coated with silicone resin.

In the case of plastic movable spherical valve bodies, it is desirable to mix a contrast medium into the plastic material so that the position of the movable spherical valve bodies 8c, 9c can be confirmed by X-ray photography as in the case of metal ones. .

The flow rate switching mechanism 5 controls the predetermined flow rate Q as described above.

Flow path to control the distribution of! A first flow rate switching section 5a equipped with a slit type relief valve 6 and a pole type on-off valve 8 inserted into the predetermined flow rate Q! It is composed of a second flow rate switching section 5b equipped with a slit type relief valve 7 inserted in the flow path 14 and a pole type on-off valve 9 to control the flow of (-1/2Q,), Valve body 8c in these on-off valves 8.9.

The moving directions F, , F of the shunt body 1 are configured to be parallel to each other and parallel to the center lines C and L of the shunt body 1.

Furthermore, the orientation of the valve seats 8a, 9a facing the valve chambers 8b, 9b of the pole type on-off valves 8, 9 is set so as to be inclined toward the center from the moving direction F, , F2 of the valve bodies 8c, 9c. has been done.

That is, the first flow paths 13 and 14 are connected in a straight line between the center of the small chamber 12 and the center positions of the circular seats 8d and 9d.
are formed, and valve bodies 8c, 9c are formed from the circular seats 8d, 9d.
If you follow the direction of movement of the circle in the opposite direction to the circles 8e and 9e,
Soft rear wall 1 d, 1 forming the outer wall of the immediate shunt body 1
e is placed.

Moreover, the first and second flow rate switching parts 5a and 5b have a function as a shutoff valve mechanism V by being closed simultaneously.

In addition, the code|symbol 20 in a figure shows a brain, and 21 shows a dura mater.

Since the intracranial pressure measuring device as an embodiment of the present invention is configured as described above,
With A implanted in a predetermined position, intracranial pressure can be measured by performing the following procedure.

Step (1) A shutoff valve mechanism V capable of blocking the flow of cerebrospinal fluid from the ventricular catheter 2 to the peritoneal catheter 3 is operated to close in the shunt body 1, thereby blocking the flow of cerebrospinal fluid.

In this case, the shutoff valve mechanism V is operated by simultaneously closing the first and second flow rate switching sections 5a and 5b.

Step (2) cerebrospinal fluid is guided through the ventricular catheter 2 to the intracranial pressure measurement reservoir 11 buried under the scalp 16 and on the skull 17, and the upper dome lla of the reservoir 11 is removed by the pressure of the cerebrospinal fluid. Expand it so that it protrudes towards the direction.

Step 0) As shown in FIG. 1, fix the air chamber B on the scalp 16 so that the visible membrane 27 of the air chamber B is above the upper dome 11a of the reservoir 11.

Step (4) Activate the air pump 104 and open the supply pipe 105.
Air is sent into the air chamber B through the air chamber B, and the inside of the air chamber B is pressurized to an appropriate pressure.

Step (5) Let the pressure value displayed on the display when the pressure in air chamber B becomes constant be the measured pressure value.

The flexible membrane 27 of the air chamber B during the above measurement operates as follows depending on the magnitude relationship between the pressure Po within the air chamber B and the intracranial pressure Pi.

■ When Po) Pi (see Figure 14).

Since Po is greater than Pi, the visible membrane 27 pushes down on the scalp 16 and the upper dome 11a of the reservoir 11 and expands downward.

At this time, since a gap is created between the inner surface of the flexible membrane 27 and the small opening 26, the air in the air chamber B is
6 and the exhaust port 25.

Since the air leaks, the pressure Pa in the air chamber B decreases, and eventually the gap disappears and there is no near leak. In other words, Po and Pi are equal (Po=P
i) The inner surface of the flexible membrane 27 just closes the small opening 26. This is because the flexible membrane 27 has a thickness t in the center so that when Po and Pi are equally balanced, the inner surface of the flexible membrane 27 just closes the small opening 26. This is because it has been done.

■ When Pi) Pa (see Figure 15).

Since Po is smaller than Pi, the flexible membrane 27 is pushed into the air chamber B.

At this time, the inner surface of the flexible membrane 27 closes the small opening 26.

Therefore, there is no near leak from inside the air chamber B, and the air supplied from the air pump 104 accumulates inside the air chamber B. As a result, Po and P
PO increases until i becomes equal (Po=Pi).

Furthermore, if Po becomes larger than Pi, the result will be as shown in (■) above.

As shown above, ■Pa)Pi and ■Pi>Pa
In either case, Po=Pi in the end.

Note that when Po and Pi are equal, the outer surface of the flexible membrane 27 has a planar shape with no curvature.

The above measurement procedure (5) is a procedure for setting the pressure value when Po=Pi as the measured pressure value.

The principle of lid internal pressure measurement is based on the premise that the following conditions hold, and the measurement is performed on the following measurement target.

First, as shown in FIG. 1, the conditions are that intracranial pressure is derived directly below the scalp 16, and that a pressure equal to the intracranial pressure exists in a "soft" dome lla of radius r.

In this case, the object to be measured is the pressure within the ventricular shunt main body 1, which is implanted under the scalp 16.
Measured indirectly from the outside of 6.

At this time, it is assumed that there is almost no change in intracranial pressure even if the scalp 16 and reservoir 11 are lightly compressed.

At this time, the following measurement principle is derived from Laplace's theorem.

As shown in FIG. 12, when considering the scalp 16 and the dome lla of the ventricular shunt body l as part of a sphere with radius r, the sphere has internal pressure (brain pressure) Pi and external pressure (usually large Laplace's theorem is established between the atmospheric pressure) Pa and the tension T of the scalp 16 and the dome lla of the ventricular shunt body 1.

P 1-Po-2T/r # a (1) Here, when measuring the internal pressure Pi from outside the dome lla,
It suffices if the condition that Pi=Po is satisfied under (1) 2''.

Based on Laplace's theorem, the following measurement principle is established.

Now, the outside of the dome lla is covered with a board 2 as shown in Figure 13.
Try applying pressure at 9. The upper surface of the dome lla is made flat by the plate 29. Assuming that the area of the planar portion of this plate 29 is D, in the region of D, r is equivalent to infinity when considered based on Laplace's theorem.

That is, if r is ψ, the right side of equation (1) becomes Ol, and in this case P i ! PG is established. From this, it can be seen that when the dome lla and the scalp 16 are compressed with an appropriate external pressure, the external pressure applied to the planar portion becomes equal to the internal pressure.

Therefore, it is necessary to pay attention to the following two points.

(1) Pressing the dome lla in a flat shape; (2) Detecting external pressure only in the above-mentioned areas. When these conditions are met, actual measurements can be carried out.

As shown above, in this example, the above (1) and (
Intracranial pressure can be measured by satisfying the condition 2).

Furthermore, this embodiment has a function of switching the flow rate as follows.

As shown in FIG. 8(d), a movable spherical valve body 8c.

9c are seated on the open position retaining seats 8e and 9e, respectively, the cerebrospinal fluid that has flowed from the patient's ventricle 19 through the ventricular catheter 2 into the reservoir 11 flows through the main passage 10 and the first and second through the flow passages 13 and 14 of the valve chamber 8.
b, 9b, passes through the two open release valves 8, 9, and enters the upstream side of the relief valve 6.7.

At this time, if the difference between the pressure of the cerebrospinal fluid upstream of the relief valve 6.7 and the pressure of the cerebrospinal fluid downstream of the relief valve 6.7 is equal to or greater than a predetermined value, the relief valve 6.7
．． 7 is opened, cerebrospinal fluid flows into the small chamber 12, and the cerebrospinal fluid in this small chamber 12 further passes through the peritoneal catheter 3 and flows into the patient's abdominal cavity and atrium.

In this way, the cerebrospinal fluid from the ventricles flows at the maximum flow rate as the sum (q++q*) of the respective regulated flow rates of the two relief valves 6 and 7.

Next, if you want to set the flow rate to a medium Q, as shown by the chain line in FIG. It is sufficient to seat the movable spherical valve body 9c on the circular seat 9d and close the second on-off valve 9, thereby allowing the cerebrospinal fluid to flow only through the first relief valve 6, which has a relatively large regulated flow rate. Can be done.

In addition, when it is desired to reduce the flow rate to Q2, as shown by the solid line in FIG. It is sufficient to seat the body 9c on the circular seat 9e and close the second on-off valve 9, thereby allowing the cerebrospinal fluid to flow only through the second relief valve 7, which has a relatively small regulated flow rate.

As mentioned above, in this embodiment, the first relief valve 6 and the second relief valve
Since the relief valves 7 have mutually different regulated flow rates, the two relief valves 6 and 7 perform three-stage flow rate switching and shutoff, but both relief valves 6 and 7 have the same regulated flow rate. Even in the case of having a flow rate, the flow rate can be switched in two stages: when the flow rate is made to flow only to one side, and when it is made to flow to both sides.

When it is desired to stop the outflow of cerebrospinal fluid via this ventricular shunt, the movable spherical valve bodies 8c and 9c are guided to the closed position holding seats 8d and 9d, respectively, and the first and second on-off valves 8 9 may be closed to block both the flow of cerebrospinal fluid from the reservoir 11 to the relief valves 6 and 7 through the main passage 10 and the first and second passages 13 and 14.

Further, in this embodiment, as shown in FIGS. 8(a) to 8(d), a circular seat 8d is used to hold the valve bodies 8c and 9c in the closed position.

When moving from 9d to the open position holding circular seats 36, 9e, the soft upper wall 1a and the soft rear wall l d, 1 e
Just press it with your fingers 18 over the scalp 16.

Further, the valve bodies 8c, 9c are held in the open position by the circular seats 8e, 9.
When moving from e to the closed position holding circular seats 8d, 9d, the soft upper wall 1a and the soft front wall 1b, 1c
Just press it with your fingers 18 over the scalp 16.

According to this embodiment, the moving directions Fl and F of the valve bodies 8c and 9c
2 are configured to be parallel to each other, it is easy to visually or tactually check the open/close state of the on-off valves 8.9.

〔Effect of the invention〕

As detailed above, according to the intracranial pressure measuring device of the present invention, the following effects and advantages can be obtained.

(1) There is no need to perform pressure zero point adjustment (calibration) for pressure measurement after implantation.

(2) The construction can be such that buried objects do not interfere with the creation of tomographic images by CT scanners, nuclear magnetic resonance scanners, etc.

(3) It is easy to handle and does not cause invasiveness such as brain damage when not being measured.

(4) Implantation surgery can be performed easily.

(5) Can be realized at low cost.

(6) It also functions as a ventricular shunt.

[Brief explanation of the drawing]

Figures 1 to 15 show an intracranial pressure measuring device as a first embodiment of the present invention, with Figure 1 being a schematic vertical sectional view showing its measurement state, and Figures 2 and 3 showing its air chamber, respectively. 4 is a schematic diagram of the measurement system, and FIG. 5 is a cross sectional view showing the ventricular shunt for intracranial pressure measurement used in this device (as viewed from the V-V arrow in FIG. 1). cross-sectional view)
, FIG. 6 is a sectional view taken along the line Vl-Vl in FIG. 5, FIG. 7 is a sectional view taken along the line ■-■ in FIG.
■A cross-sectional view taken along the arrows, and Figures 8 (b) to (d) are schematic diagrams for explaining the action during burial. Figure 9 is a cross-sectional view taken along the ff-ff arrow in Figure 5, and The figure is X- in Figure 5.
11 is a plan view showing an enlarged view of the section ■ in FIG. 5; FIG. 12.13 is a schematic perspective view and side view for explaining the measurement principle; FIG. 14.15 The figure is a schematic sectional view for explaining changes due to the pressure state of the air chamber, Figures 16 and 17 show a conventional intracranial pressure measuring device, and Figure 16 is a schematic diagram showing its overall configuration. , FIG. 17 is an enlarged sectional view showing the detection portion. 1... Shunt body (relay room), 1a... Soft upper wall, l
b, lc = soft anterior wall, ld, 1e = soft posterior wall, 2... ventricular catheter, 2a... proximal end, 2b... distal end, 3...
・Peritoneal catheter, 3a... Proximal end, 4... Check valve, 5
...Flow rate switching mechanism, 5a...First flow rate switching section, 5b.
・Second flow rate switching unit, 6...Slit type relief valve as first flow rate adjustment unit, 6a...Slit, 7...Second
Slit type relief valve as a flow rate adjustment part, 7a...
Slit, 8... Pole type on-off valve as the first on-off valve, 8a... Circular valve seat, 8b... Valve chamber (upstream compartment),
8c...Movable spherical valve body, 8d...Circle seat for maintaining closed position,
8e...Circular seat for holding open position, 9...Pole type on-off valve as second on-off valve, 9a...Circular valve seat, 9b...Valve chamber (upstream compartment), 9c...Movable spherical valve Body, 9d...Circle seat for holding closed position, 9e...Circle seat for holding open position, 10
...Main passage, loa... Branch, 11... Reservoir, l
la... Thin film-like flexible curved dome for intracranial pressure measurement, 12
...Small chamber (downstream compartment), 13...First channel, 1
4. Second channel, 15. Suture through hole, 16. Scalp, 17. Skull, 18. Finger, 19. Ventricle, 20.
・Brain, 21..Dura mater, 23..Measurement port, 24..Supply port, 25..Exhaust port, 26..Small opening, 27..Flexible membrane,
29...Plate, 33...IJ IJ-member with valve, 10
0...Pressure sensor, 101...Pressure amplifier, 102...Display device, 103...Aperture, 104...Air pump, 105...
・Supply tube, 106... Piping, A... Ventricular shunt for intracranial pressure measurement, B... Air chamber, C, L... Center line, ■
...Shutoff valve mechanism.

Claims (1)

[Claims] A ventricular catheter whose tip is inserted into the ventricle to draw cerebrospinal fluid from the same ventricle, and a ventricular catheter that is connected to the proximal end of the ventricular catheter to guide the cerebrospinal fluid and is buried under the scalp and on the skull. A flexible intracranial pressure measuring reservoir formed in the upper part of the reservoir so as to protrude outward, and capable of being expanded by the pressure of the cerebrospinal fluid and deflecting in response to pressure from an external force. In addition to the shunt for intracranial pressure measurement in which a curved dome is formed, there is also an air chamber having a flexible membrane as a wall that can be contacted from the outside through the scalp, and an air chamber that protrudes into the chamber and has the above-mentioned shunt. an air discharge section having a small opening facing the inner surface of the flexural membrane; an air supply section communicating with the air chamber and capable of supplying air at a constant flow rate into the air chamber; A pressure measuring means consisting of an air pressure measuring section capable of measuring the air pressure within the air chamber and a pressure display connected to the measuring section capable of displaying the air pressure within the air chamber is combined. Features: Intracranial pressure measuring device.