JPS5844383B2 - Fluid pressure regulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid pressure adjustment device that is effective when applied to, for example, adjustment of ultraleak overpressure in an artificial kidney device, and particularly relates to an improvement in a gas pressure measurement device.

In artificial kidney devices, particularly positive pressure type artificial kidney devices that perform ultraleakage by applying pressure higher than atmospheric pressure to blood, it is important to keep this ultraleakage pressure almost constant during hemodialysis.

For this purpose, a pressure regulator with a double tube structure consisting of a flexible inner tube and a non-flexible sealed outer tube is inserted into the blood flow path, and a pressure higher than atmospheric pressure is applied to the sealed outer tube. A device for automatically keeping blood pressure constant is known from Japanese Patent Application Laid-Open No. 50-88883 filed by the applicant of the present application.

In this fluid pressure regulating device, a separate sealed container is provided in communication with the outer tube in order to increase the substantial volume of the sealed outer tube.

If the substantial volume of the outer tube is increased by providing a sealed container in this manner, there is a risk that a large amount of air or the like will be mixed into the blood when the inner tube of the pressure regulator is damaged.

For this reason, the applicant has already filed an application for a device in which a separation means such as an elastic membrane is provided in the sealed container to restrict the outflow of air from the sealed container when the inner tube is broken. Gansho 49-147859).

By the way, in such a fluid pressure regulating device, it is desirable to measure the pressure of the air or the like sealed in the sealed outer tube of the pressure regulator with a pressure gauge in order to balance the pressure with the fluid pressure to be controlled.

In the apparatus configured as described above, it is convenient to provide this pressure gauge in a closed container provided separately from the constant pressure regulator consisting of a double pipe.

However, as mentioned above, this sealed container is equipped with a separation means that allows airtightness and mutual pressure to be freely transmitted within the container, so accurate gas pressure can be measured without being affected by this separation means. There is a need to.

The present invention has been made in view of this problem and provides a fluid pressure regulating device that can accurately measure and display the pressure of gas sealed in the sealed outer tube of a constant pressure regulator.

FIG. 1 is a configuration diagram of a fluid pressure regulating device showing an embodiment of the present invention.

The conduit 1 is a tube whose one end is connected to, for example, a positive pressure type artificial kidney device (not shown) and blood is supplied after being dialyzed by this device, and the other end is connected to a constant pressure regulator 2.

The pressure regulator 2 is composed of an inner tube 3 made of a flexible member and a sealed outer tube 4 made of a substantially inflexible material.

One end of the inner tube 3 is connected to one end of the conduit 1, and the other end is connected to one end of a conduit 5, which is connected to, for example, a vein in the human body.

The sealed outer tube 4 of the pressure regulator 2 is connected to a closed container 6 having a sufficiently large volume compared to this volume through a communication pipe 7.

Air is fed into the closed container 6 by a manual pump 8 and set at a predetermined pressure by a pressure gauge 9.

An elastic membrane 10 made of rubber, for example, is hermetically stretched inside the closed container 6, thereby separating the inside of the closed container 6 into two parts.

This elastic membrane 10 acts to reduce the air pressure on both sides to substantially zero.

In order to limit the expansion of the elastic membrane 10, a stopper 11 made of a plate with a through hole is provided in parallel with the elastic membrane 10.

A first part 12 of the sealed container 6 separated by an elastic membrane 10 is provided with a communication port 14 communicating with the sealed outer tube 4 of the pressure regulator 2 and a pressure gauge 9, and a second part 13 is provided with a manual pump. An intake port 15 communicating with the air intake port 8 is provided.

In the fluid pressure regulating device configured as described above, the sealed container 6 and the sealed outer tube 4 of the pressure regulator 2 are initially opened to atmospheric pressure, and then sealed after being brought to atmospheric pressure.

When the manual pump 8 is operated to send in more air, the air pressure in the second portion 13 of the closed container 6 increases, which inflates the elastic membrane 10 toward the first portion 12.

As a result, the air pressure in the first portion 12 also increases, and the air pressure in the sealed outer tube 4 via the communication pipe 7 also increases.

This increase in atmospheric pressure is displayed on the pressure gauge 9, and the operator sets the pressure to a desired value by looking at the indication on this meter.

In the pressure regulator 2, the fluid pressure, such as blood, passing through the flexible inner tube 3 is automatically adjusted to a fluid pressure that is balanced with the air pressure in the sealed outer tube 4.

Therefore, by measuring the atmospheric pressure of the first portion 12 of the closed container 6 communicating with the closed outer tube 4 with the pressure gauge 9, the pressure of the fluid flowing inside the inner tube 3 of the pressure regulator 2 can be accurately set.

In the previously filed Japanese Patent Application No. 49-147859, the pressure gauge 9 is connected to the second portion of the closed container 6.

In such a configuration, due to the presence of the elastic membrane 10, the pressure is actually slightly lower in the first portion 12 than in the second portion 13 of the closed container 6.

This is because force is required to deform the elastic membrane 10 itself, and pressure loss occurs at this portion.

For this reason, the operator has to set the pressure of the pressure regulator 2 by anticipating the above-mentioned pressure drop in advance in response to the indication from the pressure gauge 9, which has the disadvantage of lacking accuracy.

Furthermore, in such a configuration, in order to reduce the pressure drop due to the elastic membrane 10, it is necessary to carefully select the material, film thickness, etc. of the elastic membrane 10.

All these drawbacks have been improved with the device of the invention.

The present invention is not limited to the embodiment shown in FIG. 1, but can be modified as shown in FIGS. 2 and 3.

In FIG. 2, a cap-shaped elastic membrane 10' such as a rubber cap is used as a means for separating the closed container 6.

This cap-shaped elastic membrane 10' is initially shaped as shown by the solid line in FIG. When air is pumped in, it is pressed as shown by the broken line in the figure, thereby increasing the air pressure in the second part 13 to the first part 12.
The pressure is transmitted through the communication pipe 7 to a constant pressure regulator (not shown).

Since the other parts have the same structure as in FIG. 1, corresponding parts are given corresponding symbols and explanations will be omitted.

FIG. 3 shows still another modification of the separating means, in which a cylinder 17 with a bottom is provided with a through hole 16 on the side surface, and the through hole 16 on the side surface of the cylinder 17 is made airtight by an elastic membrane 10''. It is covered.

In this separation means, the inside of the cylinder 17 becomes the first portion 12.

This operation is the same as in the case of FIG.

The other parts of this device are the same as those shown in FIG. 1, and detailed explanation will be omitted.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing the overall configuration of the fluid pressure regulating device of the present invention, and FIGS. 2 and 3 are sectional views of essential parts showing other modifications of the present invention. 1.5: Conduit, 2: Constant pressure regulator, 3: Inner tube, 4: Outer tube, 6:
Sealed container, γ: communication pipe, 8: manual pump, 9: pressure gauge,
1o, io', io" bielastic membrane, 11: stopper, 12
: first part, 13: second part, 14: communication port, 15: intake hole.

Claims (1)

[Scope of Claims] 1. An inner tube made of a flexible member through which a fluid passes, and an inner tube provided on the outer periphery of the inner tube so as to form a sealed chamber between the outer wall of the inner tube. an outer tube made of a member having sufficient inflexibility compared to the inner tube; an airtight container communicating with the outer tube; a means for separating the part and a second part not including a communication port airtightly and so that the pressure of the drawing part can be transmitted to each other; and measuring the pressure in the second part of the sealed container separated by this means. 1. A fluid pressure regulating device comprising: a pressure gauge provided as shown in FIG. 2. The patent device characterized in that the separating means is constituted by a cap-shaped elastic membrane that is airtightly fixed to the communicating eye portion to the outer tube.