JPH0783765B2 - Oxygenator - Google Patents

Description

TECHNICAL FIELD The present invention relates to an artificial lung capable of enhancing gas exchange performance by favorably contacting blood and oxygen via a hollow fiber.

[Prior Art] Oxygenators are roughly classified into a bubble type and a membrane type, but the membrane type oxygenator using a gas exchange membrane has a more physiological gas exchange method than the bubble type, and has an adverse effect on blood. There is an advantage that there are few.

The gas exchange method is a method of flowing blood into the hollow part of the hollow fiber and flowing gas outside the hollow fiber (blood internal perfusion type), and conversely, flowing gas into the hollow part of the hollow fiber and outside the hollow fiber. Has a method of flowing blood (external blood perfusion type).

[Problems to be Solved by the Invention] However, in the method of flowing blood into the hollow portion (blood internal perfusion type), the pressure loss between the blood inlet and the outlet becomes large, and the internal pressure of the blood circuit on the side of flowing into the artificial lung is increased. If raised and excessive, the latex rubber tube of the roller pump will bulge significantly and there is a risk of rupture. It is also known that red blood cell destruction is high when the circuit pressure is high.

Also, a method of flowing blood to the outside of the hollow fiber (blood external perfusion type)
In that case, it is generally difficult to disperse the blood uniformly, and as a result, it is difficult to bring the blood into sufficient contact with oxygen.

[Means for Solving the Problems] Therefore, the present inventor has conducted extensive studies to provide an artificial lung capable of excellent gas exchange in both the internal blood perfusion type and the external blood perfusion type. The present invention has been reached.

That is, according to the present invention, a plurality of porous hollow fibers are bundled,
Both ends of the hollow fiber are embedded in a polymer polymer partition wall in an open state, and both ends of the hollow fiber are flow-tightly sealed in the housing by the partition wall (here, flow-tightness means sealing liquid and gas). An artificial lung in which the hollow fibers are sealed substantially uniformly in the entire housing, and blood or gas inlets and outlets are provided in the central part of one partition and the peripheral part of the other partition. A featured oxygenator is provided.

[Operation] In the artificial lung of the present invention, when the inlets and outlets provided in the central portion of one partition wall and the peripheral portion of the other partition wall are used as the inlet and outlet of blood, gas is flowed inside the porous hollow fiber, so-called blood external perfusion type On the contrary, when the inlet / outlet provided in the central portion of one partition wall and the peripheral portion of the other partition wall is used as a gas inlet / outlet, on the contrary, it is a blood internal perfusion type in which blood is flown inside the porous hollow fiber. Therefore, the oxygenator of the present invention can be used as two types of oxygenator only by changing the cap, for example. Examples of the gas mentioned here include air, a gas in which air is enriched with oxygen, oxygen gas, and a gas in which nitrogen and oxygen are mixed.

In this artificial lung, when blood or gas flows outside the hollow fiber, it spreads from the central direction to the surroundings or flows toward the center from the surroundings, so that the drift of the blood or gas can be suppressed as much as possible. Therefore, the gas exchange performance can be improved.

That is, when the artificial lung is used as an external perfusion type of blood, since blood crosses the hollow fiber from various angles, uneven flow can be prevented, and a blood flow (turbulent flow) important for gas exchange can be created, and the gas exchange performance can be improved. Can be improved.

On the other hand, when this artificial lung is used as a blood internal perfusion type, gas does not flow from the inlet / outlet provided in the outer cylinder inside the partition wall as in the conventional case, so that the gas can flow evenly throughout the hollow fiber. , The performance of artificial lung is improved.

EXAMPLES The present invention will be described below based on examples shown in the drawings, but the present invention is not limited to these examples.

FIG. 1 is a sectional view showing a heat exchanger-integrated artificial lung which is an embodiment of the artificial lung of the present invention.

The oxygenator of the present embodiment is composed of a gas exchange section I and a heat exchange section II integrally arranged with the gas exchange section I.
A carbon dioxide cartridge is installed inside II.

Reference numeral 1 denotes a blood inlet for introducing blood, which is provided in the peripheral portion of a partition wall 4 described later, and this is provided continuously to the outer portion of the heat exchange portion II. In the cylinder 2 of the gas exchange section I, a large number of porous hollow fibers 3 are evenly and evenly arranged in the cylinder 2. At both ends of the cylinder 2 and the porous hollow fibers 3, the cylinders The inner surface of 2 and the outer surface of the porous hollow fiber 3 form partition walls (potting portions) 4 which are fluid-tightly supported by an adhesive (supporting member). A blood outlet 5 is provided at the center of the partition wall 4. On the outside of the partition 4, a gas inlet 6 and a partition 4 are provided.
An outlet 7 for exchange gas is provided on the outside.

On the other hand, a heat exchange tube 10 for keeping blood at a predetermined temperature is provided between the inner cylinder 8 and the outer cylinder 9 of the heat exchange section II. Further, a carbon dioxide gas cartridge 11 is loaded in the space inside the inner cylinder 8 of the heat exchange section II, and is used when priming the artificial lung. In addition, 12 is an inlet of the heat exchange medium, and 13 is an outlet of the heat exchange medium.

In the above structure, the blood flows from the blood inlet 1 to the heat exchange section II.
After having been heat-exchanged to a predetermined temperature in, the gas enters into the gas exchange part I from the peripheral part of the partition wall 4, then flows through the outer part of the porous hollow fiber 3 arranged in the cylinder 2, and reaches the central part of the partition wall 4. The blood is discharged from the blood outlet 5 provided in the. At this time, the blood is
The gas introduced from the gas inlet 6 into the hollow portion of the porous hollow fiber 3 is brought into contact with the gas through the pores formed in the porous hollow fiber 3 to perform gas exchange, but as shown in FIG. Since blood crosses the hollow fiber from various angles, uneven flow can be prevented, blood can flow evenly throughout the hollow fiber, and blood flow (turbulent flow), which is important for gas exchange, occurs and gas exchange performance Can be improved. Further, in the case of this embodiment, since the blood inlet / outlets 1 and 5 are tapered,
Blood can flow smoothly, and pressure loss and blood cell destruction can be reduced.

The arrangement shape of the heat exchange tube 10 provided between the inner cylinder 8 and the outer cylinder 9 of the heat exchange section II is not particularly limited, but a spiral or spiral shape can increase the contact area, and the heat exchange efficiency can be increased. Is improved, which is preferable. Also this tube
It is preferable to provide, for example, a spiral convex portion on the outer peripheral surface of 10, since the contact area can be similarly increased.

The material of the heat exchange tube 10 is not particularly limited, and any material having a large heat transfer coefficient can be used. For example, stainless steel, aluminum, etc., such as epoxy resin, silicon resin, fluorine resin or alumina (Al ₂ A material coated with O ₃ ) or the like is preferable.

Further, as the porous hollow fiber 3 arranged in the cylinder 2,
A polyolefin resin such as polypropylene or polyethylene, a fluororesin such as polyvinylidene fluoride or an ethylene tetrafluoroethylene copolymer, or a hydrophobic resin such as a silicone resin is preferably used. Further, even when a material other than the hydrophobic bioresin is used, it is also possible to use a material in which the contact surface with blood is treated with a silicone resin or the like to be hydrophobic. The porous hollow fiber 3 has a large number of fine pores in its peripheral wall portion, and gas exchange is performed therein. Generally, the average pore diameter of the fine pores is preferably 0.01 to 1 μm. Further, it is generally preferable that the hollow fiber 3 has a porosity of about 20 to 80%.

Further, the membrane area of the porous hollow fiber 3 is usually 3 m ² or less,
It can be made smaller than conventional commercial products. This is because, as described above, the hollow fiber allows the blood and the gas to come into sufficient contact with each other, which is a great advantage of the present invention.

Further, in the artificial lung shown in the present embodiment, even if the arrangement of the inlet and outlet of blood and the inlet and outlet of gas are reversed,
It can be easily used only by exchanging the cap, and thus can be used as two types of artificial lungs, an external blood perfusion type and an internal blood perfusion type.

Hereinafter, the results of performing gas exchange using an example of the artificial lung according to the present invention will be specifically described.

(Example) An artificial lung having the configuration shown in FIG. 1 and having the following dimensions and conditions was used.

Cylinder 2 ... Diameter 65 mm Heat exchange part outer cylinder 9 ... Diameter 84 mm Heat exchange part inner cylinder 8 ... Diameter 50 mm Overall length ... 200 mm Porous hollow fiber ... Membrane area 2 m ² Number of hollow fibers 8841 Packing density (both ends: 0.4, central part: 0.6 ) Inner diameter 300 μm Outer diameter 400 μm Peripheral wall thickness 50 μm Average pore diameter 0.22 μm Porosity 68% Supporting member (potting material)… Polyurethane resin heat exchange tube… 1 mm thick, 10 mm (φ) diameter aluminum pipe with epoxy coating It is applied, and is arranged spirally inside the inner cylinder. A convex portion is formed on the outer peripheral surface of the tube.

Using the above artificial lung, blood was drawn from the jugular vein and returned to the hip artery of an adult dog weighing 10 kg. The venous blood was converted into standard venous blood defined by AAMI and then led to the artificial lung. Blood sampling is performed at the inlet and outlet of the artificial lung, and the values are used to calculate the O ₂ transfer amount and CO ₂ transfer amount.
It is shown in FIG. Further, in order to obtain the pressure loss of the artificial lung, pressure sensors were attached to the inlet and outlet sides of the artificial lung to measure the pressure, and the results are shown in FIG. O ₂ was blown to the artificial lung at a rate of 1 / min per membrane area.

As is clear from the above results, according to the artificial lung, the O ₂ transfer amount and the CO ₂ transfer amount are sufficiently obtained, and the gas exchange performance is high.

[Effects of the Invention] As described above, according to the artificial lung of the present invention, in both the internal blood perfusion type and the external blood perfusion type,
Since blood and gas are in sufficient and good contact, good gas exchange can be performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the artificial lung of the present invention, FIG.
The figure is a graph showing the O ₂ transfer amount, FIG. 3 is a graph showing the CO ₂ transfer amount, and FIG. 4 is a graph showing the pressure loss of the artificial lung. 1 ... Blood inlet, 2 ... Cylinder, 3 ... Porous hollow fiber, 4
, 4 ... Septa, 5 ... Blood outlet, 6 ... Gas inlet, 7
…… Exchange gas outlet, 8 …… Heat exchange section inner cylinder, 9 …… Heat exchange section outer cylinder, 10 …… Heat exchange tube, 11 …… Carbon dioxide cartridge, 12 …… Heat exchange medium inlet , 13 …… Outlet of heat exchange medium.

Claims (1)

[Claims] 1. A plurality of porous hollow fibers are bundled, both ends of the hollow fibers are embedded in a polymeric polymer partition wall in an open state, and both ends of the hollow fiber are hermetically sealed in a housing by the partition wall. And an artificial lung in which the hollow fibers are substantially evenly arranged in the entire housing, wherein blood or gas inlets and outlets are provided in the central part of one partition and the peripheral part of the other partition. Artificial lung.