JPH07163661A - Drip chamber for medical use - Google Patents

Abstract

PURPOSE:To provide a drip chamber of a simple structure in which gas can be eliminated without requiring a liquid level detection sensor by forming a ventilation hole to make the inner side communicate with the outer side in a container main body, and installing a hydrophobic porous body on an aperture part of the container main body communicating with the ventilation hole. CONSTITUTION:A ventilation hole 25 to make the inner side communicate with the outer side is formed on the upper surface of a container main body 24 of a drip chamber 23, and an entrance conduit 20 for liquid is installed on a side surface of the container main body 24. A ventilation tube 26 is inserted into the ventilation hole 25, a filter 27 and a check valve 28 are installed at a part of the ventilation tube 26 on the outer side of the container main body 24, and a hydrophobic porous body 29 is installed at a tube end aperture part opened facing the container main body 24 of the ventilation tube 26. An installation height of the hydrophobic porous body 29 is set to be a desirable liquid surface level in the drip chamber 23 to be held. When gas staying in an air chamber 16 becomes excessive, pressure in the air chamber 16 rises to push down the liquid surface level. When the liquid surface level falls to the position of the hydrophobic porous body 29, excessive air is discharged out, thereby the liquid surface level is regulated automatically.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an artificial heart-lung machine, an artificial kidney,
Regarding a medical drip chamber equipped in the blood or plasma circuit for extracorporeal circulation such as blood purification, technology that keeps the liquid level in the chamber constant by removing excess gas in the blood staying in the chamber It is about.

[0002]

2. Description of the Related Art In medical devices such as blood processing devices,
Blood components such as blood cells and plasma taken out of the body are processed to remove unnecessary substances, and then returned to the body for circulation. In these medical devices, blood is taken out directly from the patient's body and returned, so that it is important not to affect the patient's body. For that purpose, it is necessary to control blood pressure, plasma pressure and plasma filtration pressure in the treatment process, and further return blood pressure so as to be within a predetermined range.

For example, a conventional blood processing apparatus 1 shown in FIG.
In this case, the blood collected by the blood pump 2 is supplied to the plasma filter 3 and separated into blood cell components and plasma.
The separated plasma is supplied to the plasma filter 5 by the plasma pump 4, where harmful polymer components contained in the plasma are filtered. Then, the plasma is discharged in a concentrated state by the plasma removal pump 6. At this time, if necessary, the replacement liquid 7 is replenished via the replacement liquid pump 8 in an amount commensurate with the concentrated plasma discharged by the plasma removal pump 6. The plasma thus treated is mixed with the previously separated blood component and then returned to the body through the bubble detector 9.

Therefore, in the blood processing apparatus 1,
A blood sampling detector 10, a blood filtration pressure gauge 11, a plasma pressure gauge 12, and a plasma filtration pressure gauge 1 in the middle of the above-mentioned processing route.
A total of 5 pressure detectors, 3 and a blood return pressure gauge 14, are installed to detect the presence or absence of abnormality. A drip chamber 15 as shown in FIG. 4 is used as these pressure detectors. In addition to measuring the pressure, the drip chamber 15 also has a function of separating and removing the gas at the time of priming and the gas mixed in blood or plasma.

In such a drip chamber 15, an air chamber 16 formed in the upper portion thereof is connected to a strain gauge type pressure sensor 18 via a pressure guiding tube 17. A filter 19 that allows the passage of air but blocks the passage of liquid is installed in the middle of the pressure guiding tube 17. In addition, the air chamber 16 of the drip chamber 15
Is connected to the liquid inlet line 20 and the air venting line 21.

On the other hand, a liquid outlet conduit 22 is connected to the lower end of the drip chamber 15. The air vent pipe 21 is for positioning the liquid level of the liquid in the drip chamber 15, and is normally closed.

The pressure is detected by the drip chamber 1
The pressure of the air chamber 16 of No. 5 is detected by the pressure sensor 18. In the conventional blood processing apparatus 1,
In this way, the pressure is detected by using the drip chamber 15, and the above-mentioned blood pressure, blood filtration pressure, plasma pressure, plasma filtration pressure, blood return pressure, etc. are detected.

Further, in the prior art, the height of the liquid surface in the chamber is measured by a photoelectric tube system or an ultrasonic system, and the height of the liquid surface is kept constant, so that blood collection pressure, blood filtration pressure, etc. Some have even kept the pressure constant.

[0009]

In the drip chamber 15 as described above, the liquid level in the chamber is increased in order to save time and accuracy as a preparatory step before the treatment of the blood processing apparatus 1. Is automatically kept constant. However, in order to keep these liquid level heights constant, the gas release automatic valve (not shown) of the air vent pipe 21 is used by using the pressure sensor 18, the photoelectric tube type or ultrasonic type liquid level detection sensor described above. ) And the like are required to be automatically controlled, and an electronic circuit for that purpose is also required. Therefore, there is a drawback that the whole blood processing apparatus 1 is large-scaled.

In addition, in the photoelectric tube type or ultrasonic type liquid level detection sensor, the liquid contact portion is sterilized, and it is necessary to dispose of it in order to prevent infection of diseases. The liquid level detection sensor is inevitably attached from the outside of the main body of the drip chamber 15. However, it is necessary to pay special attention when mounting from the outside,
In addition, it may cause malfunction. Therefore, there has been a demand for a drip chamber having a simple structure capable of removing gas without requiring a liquid level detection sensor.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made by improving the above-mentioned problems in view of the above-mentioned problems, and it is possible to automatically discharge excess gas in a chamber without the need for a liquid level detection sensor. It is intended to provide a drip chamber capable of keeping the liquid surface water level constant.

Thus, in order to solve the above-mentioned problems, the means adopted by the present invention is that the container body is provided with a vent hole for communicating the inside and the outside, and the opening in the container body communicating with the vent hole is made hydrophobic. It is a medical drip chamber characterized by having a porous body attached.

[0013]

In the drip chamber of the present invention, the vent hole for communicating the inside and outside of the container body with the opening in the container body,
A hydrophobic porous body is attached. This hydrophobic porous body is a porous material composed of molecules which are hardly soluble in water and have a property of being hydrophobically bonded so as to reduce the contact area with water. Therefore, the hydrophobic porous body can discharge only the air in the drip chamber and cannot pass the liquid.

Therefore, when the pressure of the gas phase in the drip chamber becomes high, the liquid surface is pushed down to the position of the hydrophobic porous body. Then, excess air is discharged through the hydrophobic porous body, and along with this, the water level of the liquid surface is restored to the upper limit position of the hydrophobic porous body.

As described above, it is possible to automatically keep the liquid level in the drip chamber constant through the hydrophobic porous body. That is, it is possible to omit a special ultrasonic type or photoelectric tube type liquid level detection sensor and a gas discharge automatic valve, which are conventionally required, and an electronic circuit for controlling them.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the embodiments shown in the drawings. The same reference numerals as in the conventional case are the same members. FIG. 1 is a vertical sectional view of a drip chamber 23 according to the first embodiment of the present invention. As shown in the figure, in this first embodiment, a vent hole 25 that communicates the inside and the outside is formed on the upper surface side of the container body 24, and the liquid inlet pipeline 20 is installed on the side surface of the container body 24. ing.

A ventilation pipe 26 is inserted through the ventilation hole 25, and a filter 27 and a check valve 28 are provided on the outside of the container body 24 of the ventilation pipe 26. Vent pipe 2
In the pipe end opening portion that faces the inside of the container body 24 of 6,
A hydrophobic porous body 29 made of ethylene tetrafluoride or the like having a pore diameter of 0.1 to 1.0 μm is attached. The height position where the hydrophobic porous body 29 is installed is the drip chamber 23.
Is set to the liquid level that you want to keep. Other configurations are the same as those in the conventional case.

By the way, the hydrophobic porous body 29 can also have a function as a sterilizing filter by selecting its pore size, and such a sterilizing filter is not always necessary. However, in the first embodiment, the filter 27 is separately attached for safety reasons. The check valve 28 is for preventing gas from flowing back into the container body 24 through the ventilation pipe 26 when the container body 24 is in a reduced pressure state.

Thus, in the drip chamber 23 of the first embodiment having such a structure, when the gas staying in the air chamber 16 becomes excessive, the pressure in the air chamber 16 gradually rises and the liquid It will push down the water level. Then, when the liquid surface water level drops to the position of the hydrophobic porous body 29, excess air in the air chamber 16 is discharged from the hydrophobic porous body 29 through the ventilation pipe 26 to the outside, and the liquid surface water level is this hydrophobicity. The position of the porous body 29 is automatically adjusted. That is, the blood collection pressure, blood filtration pressure, plasma pressure, plasma filtration pressure, blood return pressure, etc. in the blood processing apparatus 1 shown in FIG. 3 can be automatically adjusted using the drip chamber 23.

By the way, the operation of the drip chamber 23 as described above requires that the inside of the drip chamber 23 be in a pressurized state. Drip chamber 23
When the inside is in a negative pressure state, the pressure inside the drip chamber 23 is made higher than that on the secondary side of the ventilation pipe 26 by communicating the ventilation pipe 26 with a vacuum pump or the like, so that a pressure is applied. You can use it.

FIG. 2 is a vertical sectional view of a drip chamber 30 according to the second embodiment of the present invention. In this embodiment, the vent hole 25 is provided on the side surface of the container body 24, and the hydrophobic porous body 29 is attached to the opening of the vent hole 25 in the container body 24. The basic operation of the hydrophobic porous body 29 and other configurations and operational effects are the same as those in the case of the first embodiment.

[0022]

[Experimental Example] As a result of performing an experiment as to whether or not the liquid surface water level can be kept constant by using the drip chamber 23 from which the filter 27 and the check valve 28 of the first embodiment shown in FIG. 1 are removed. Is as follows. Hydrophobic porous body 2
As for 9, a tube-shaped one made of tetrafluoroethylene and sealed at one end was used. The average pore size is 0.45
μm, porosity 60%, thickness 0.5 mm, tube length 1 cm.

In the experiment, the empty drip chamber 2 is assumed by assuming the degassing at the time of priming in the blood processing apparatus 1.
Water is pumped into the liquid from the liquid inlet pipe line 20, the liquid outlet pipe line 22 is squeezed with a valve, and the inside is about 100 mmHg.
Was carried out under pressure. Further, in order to confirm the release of gas, a tube was attached to the outlet side of the ventilation pipe 26 and the tube was immersed in a flask containing water.

As a result, the gas in the drip chamber 23 and the pipe was discharged as bubbles through the hydrophobic porous body 29 into the flask. At this time, when the liquid level rises until it comes into contact with the hydrophobic porous body 29, the release of gas stops and the water level on the liquid level stabilizes.

Subsequently, water was continuously fed, and air bubbles were injected into the drip chamber 23 from the water absorption side of the pump with a syringe. As a result, although the liquid surface water level in the drip chamber 23 temporarily drops, excess gas is sequentially released into the flask, and the liquid surface water level is maintained at the same water level as the set position of the hydrophobic porous body 29. It was confirmed.

As is clear from the results of these experiments,
The liquid surface water level in the drip chamber 23 can be automatically adjusted to the set water level only by using the hydrophobic porous body 29.

By the way, the present invention is not limited to the above-mentioned embodiment, and for example, the hydrophobic porous body 29 is
If the vent hole 25 is of a type formed on the side surface of the container body 24, the vent pipe 26 may be omitted by directly mounting the vent hole 25 in the container body. Further, the shape and size of the hydrophobic porous body 29 can be arbitrarily changed.

[0028]

As described above, according to the present invention,
Since a hydrophobic porous body that allows gas to pass but does not pass liquid is attached to the opening in the container body of the vent hole that communicates the inside and outside of the container body, excess air in the drip chamber is automatically passed through the hydrophobic porous body. The liquid level in the chamber can always be automatically adjusted to the upper limit position of the hydrophobic porous body.

That is, it is possible to omit a special ultrasonic type or photoelectric tube type liquid level detection sensor and an automatic valve for releasing gas, which are conventionally required, and an electronic circuit for controlling them. In addition, it is possible to provide a medical device at a very low cost, and it is possible to remarkably reduce the time and labor required for preparing medical procedures.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a drip chamber according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a drip chamber according to a second embodiment of the present invention.

FIG. 3 is an overall block diagram of a conventional blood processing apparatus.

FIG. 4 is a partial vertical sectional front view of a conventional drip chamber.

[Explanation of symbols]

23 ... Drip chamber 24 ... Container body 25 ...
Vent hole 26 ... Vent tube 29 ... Hydrophobic porous body

Claims (1)

[Claims] 1. A ventilation hole for communicating the inside and the outside is provided in the container body,
A drip chamber for medical use, wherein a hydrophobic porous body is attached to an opening in a container body communicating with the ventilation hole.