JPS63189160A - Hollow yarn type artificial lung excellent in gas exchange efficiency - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an artificial lung that removes carbon dioxide from the blood and adds oxygen to the blood through extracorporeal blood circulation. More specifically, the present invention relates to a membrane oxygenator using a hollow fiber membrane.

[Conventional technology]

Conventionally used oxygenators can be broadly classified into bubble-type and model oxygenators, and the development of model oxygenators is active because they cause less blood damage and are safer. Among these, hollow fiber oxygenators, which are formed by bundling a large number of hollow fibers and storing them in a housing, are attracting particular attention because the device can be made smaller compared to the membrane area.

[Problem that the invention seeks to solve]

In most conventional hollow fiber oxygenators, blood flows inside the hollow fibers and oxygen-containing gas flows outside to perform gas exchange. There was a problem in that the membrane resistance for gas movement became large, and the original performance of the membrane was not fully exhibited, resulting in a low gas exchange capacity (gas exchange efficiency) per membrane area. Therefore, in order to solve such problems, Japanese Patent Application Laid-Open Nos. 58-155862, 60-225572, and 60-253 have been published.
No. 458, etc., proposes a so-called external perfusion method in which blood flows outside the hollow fibers and oxygen-containing gas flows inside the hollow fibers. Although this method produces some effects, it is insufficient, and further improvements have been desired.

An object of the present invention is to provide a hollow fiber oxygenator with even better gas exchange efficiency.

[Means for solving problems]

The present invention achieves the above-mentioned object by employing an external perfusion system and providing means for periodically changing the pressure of the oxygen-containing gas.

That is, the present invention provides a hollow fiber oxygenator in which a large number of hollow fibers are housed in a housing provided with a blood inlet and an outlet and a gas inlet and an outlet. and the outflow port to form a gas flow path, and the space formed by the inner surface of the housing and the outer surface of the hollow fiber to communicate with the blood inflow port and the blood outflow port to form a blood flow path; Periodically changing the gas pressure in the flow path [effect] The reason why the oxygenator of the present invention has excellent gas exchange efficiency is not clear, but by periodically changing the gas pressure, the hollow fibers vibrate, This is thought to be because this is transmitted to the blood side, generating turbulence and reducing membrane resistance for gas movement.

〔Example〕

Hereinafter, the present invention will be explained in more detail using the drawings.

FIG. 1 is a sectional view of a main body portion 1 of an embodiment of the oxygenator of the present invention, excluding the vibration generating means, and basically has the same structure as a conventional hollow fiber oxygenator. That is, the hollow fibers 7 are housed in a bundle inside the housing Z, and both ends of the hollow fibers are adhesively fixed with a curable resin such as polyurethane in an open state. The housing L is provided with a gas inlet 4, a gas outlet 3, a blood inlet 5, and a blood outlet 6. The M element-containing gas is introduced into the main body through the gas inlet 4, enters the hollow fiber from the right end in the figure, passes through the hollow fiber, reaches the left end, and is discharged through the gas outlet 3. - 10,000 blood is introduced into the housing from the blood inlet 5, and while flowing outside the hollow fiber, gas exchange is performed with the oxygen-containing gas flowing inside the hollow fiber, and at the same time, acid is accumulated and carbon dioxide is added. is removed, converted into arterial blood, and discharged from the blood outlet 6. Hollow fiber 7 has an inner diameter of 100
It is a gas permeable membrane with a thickness of about 20 to 200 pm, and preferably made of silicone rubber or porous polypropylene. In the illustrated embodiment, the hollow systems are bundled in parallel, but one or several hollow systems may be bundled so as to cross each other.
In addition, by adjusting the tension of the hollow fiber so that the hollow fiber can easily vibrate, or by providing a protrusion inside the housing that pushes the middle of the hollow fiber from the outside, vibration nodes are formed when the hollow fiber vibrates. You may also do so. Further, although the blood inlet and blood outlet are provided in the same direction of the housing, they may be provided in opposite directions.

Next, FIG. 2 shows a block diagram of the principle of the artificial lung of the present invention.As mentioned above, the oxygenator main body 1 has a blood inlet 5.
Blood is supplied from the blood outlet 6 and discharged from the blood outlet 6. Blood is supplied using a pump 9.

Furthermore, blood can be supplied only by differential pressure without using a pump. Then, the @ element-containing gas is supplied from the gas inlet 4 and discharged from the gas outlet 3. A vibration generating means 8 is provided just before the gas inlet 4 to give pressure vibrations to the supplied gas and to periodically adjust the pressure. to change. The appropriate frequency for the 1st shift to be given is in the range of 10 to 5011z,
Since the optimal frequency varies depending on the size and shape of the oxygenator body used, it is preferable to experimentally determine the frequency that will increase the gas exchange efficiency in advance. Therefore, it is preferable that it is 3 mHg or more. There is no particular shed, but if it is too large, there is a risk of damaging the hollow fibers, etc.

FIG. 3 shows an embodiment of the vibration generating means 8 as a sectional view. The apparatus includes a container 10 connected to an oxygen-containing gas supply circuit.
．． a rubber diaphragm 11 provided within the container 10;
Morph for vibrating the diaphragm 12. Movable wall 1
4 and a motor 15 for moving the movable wall.

The diaphragm 11 and the motor 12 are connected to the crankshaft 1
3, and the diaphragm vibrates up and down as the motor rotates. Also, movable wall 1
4 can be moved up and down airtightly by a motor 15, thereby making it possible to change the internal volume of the container. Container 10. Since the volume of the chamber 16 surrounded by the diaphragm 11 and the movable wall 14 changes periodically when the diaphragm is vibrated, the pressure of the oxygen-containing gas flowing inside the chamber 16 changes periodically. The frequency of vibration can be adjusted by changing the rotation speed of the motor 12, and the width can be adjusted by changing the volume of the chamber 16 by moving the movable wall 14, or by changing the vibration width of the diaphragm. Can be adjusted.

Furthermore, a valve such as a check valve may be provided at the inlet or outlet of the chamber 16 in order to more sensitively transmit pressure changes.

Practical Example 1 An oxygenator main body having the structure shown in FIG. 1 using silicone hollow fibers (membrane area: 0.5 m, inner diameter: 200 μm).

A vibration generator having a structure shown in FIG. 3 was connected as shown in FIG. 2.

Next, oxygen gas was flowed at a flow rate of 11/min, and a 20% solution of artificial blood (FC-43 manufactured by Green Cross) was added at 100ml/t1.
The amount of oxygen transferred from the gas side into the artificial blood was measured by applying vibrations at a frequency of 3011z and an amplitude of 5 mHg to the oxygen gas.

As a result, the amount of oxygen transfer was 5.63 mN/min.

Comparative Example 1 The amount of oxygen transfer was measured in the same manner as in Practical Example 1, except that no vibration was applied, and it was found to be 4.08 m/! /minute. Comparing this result with the result obtained in Practical Example 1, the amount of oxygen transferred by applying vibration was 1.38.
It turns out that it doubles.

Implementation example 2: Instead of artificial blood - 300m of fresh heparinized blood!
! /min flow rate, frequency 20 Hz, amplitude 7ta
The same procedure as in Example 1 was carried out except that Hg vibration was applied.
The amount of oxygen transferred into the blood from the gas side was measured. As a result, the amount of oxygen transferred per 1 dl per night is 3.98 m1! Met.

Comparative Example 2 The oxygen transfer amount was determined in the same manner as Example 2 except that no vibration was applied, and it was 2.48 mE/df.
It was fi. Comparing this result with Example 2,
It can be seen that by applying vibration, the amount of oxygen transferred increases by 1.60 times.

As is clear from the above results, the oxygenator of the present invention has superior gas exchange efficiency compared to conventional oxygenators. In the present invention, it is necessary to adopt an external perfusion system in which blood flows outside the hollow fibers, and this is also an important point of the invention. That is, even if pressure vibrations are applied to the gas in an internal perfusion system in which blood flows inside the hollow fiber and oxygen-containing gas flows outside the hollow fiber, little improvement in gas exchange efficiency is observed.

〔Effect of the invention〕

Since the oxygenator of the present invention has high gas exchange efficiency, it is possible to obtain the necessary gas exchange ability even if the membrane area is smaller than that of conventional oxygenators. Therefore, since it can be made smaller than a conventional oxygenator, the amount of blood filled during use can be reduced, and the burden on the patient can be reduced. Furthermore, since it has a simple structure in which a vibration generating means is simply provided in a conventional hollow fiber oxygenator, it is easy to manufacture and is excellent in terms of economy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main body portion of the oxygenator according to the embodiment of the present invention, excluding the vibration generating means. Further, FIG. 2 is a block diagram of the artificial lung of the present invention, and FIG. 3 is a sectional view of one embodiment of the vibration generating means used in the present invention. l...Artificial lung body 2...Housing 3...
Gas outflow port 4...Gas inflow port 5...Blood inflow port 6...Blood outflow lower...Hollow fiber
8... Vibration generating means procedure principal 1 company official document (voluntary) February 23, 1988

Claims (1)

[Claims] In a hollow fiber oxygenator in which a large number of hollow fibers are housed in a housing provided with a blood inlet and an outlet and a gas inlet and an outlet, the inside of the hollow fiber and the gas inlet and outlet are connected to each other. The space formed by the inner surface of the housing and the outer surface of the hollow fiber communicates with the blood inlet and outlet to form a blood flow path, and the gas pressure in the gas flow path is increased. An artificial lung characterized by being provided with vibration generating means for periodically changing the amount of vibration.