JPH0732801B2 - Oxygenator with integrated heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is a method in which blood is flown to the outside of a hollow fiber and oxygen is introduced into the hollow fiber. More particularly, the present invention relates to a heat exchanger-integrated artificial lung that enables blood and oxygen to come into good contact with each other through a hollow fiber and can make the apparatus extremely compact.

[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.

As the gas exchange method, there is a method of flowing blood into the hollow portion of the hollow fiber and a gas flowing to the outside of the hollow fiber, and conversely, a method of flowing gas into the hollow portion of the hollow fiber and flowing blood to the outside of the hollow fiber. is there.

[Problems to be Solved by the Invention] However, in the method of flowing blood into the hollow portion, the pressure loss between the blood inlet and the outlet becomes large, the internal pressure of the blood circuit on the side flowing into the oxygenator rises, and excessive pressure is generated. In this case, the latex rubber tube of the roller pump bulges greatly and there is a risk of bursting. It is also known that red blood cell destruction is high when the circuit pressure is high.

Further, in the method of flowing blood to the outside of the hollow fiber, it is generally difficult to uniformly disperse the blood, and as a result, it is difficult to bring the blood and oxygen into sufficient contact.

Furthermore, in such an artificial lung, when returning blood to the body, it is necessary to maintain the blood temperature at a predetermined temperature of about 36 to 37 ° C. A heat exchanger was arranged in the heat exchanger to keep the blood temperature at a predetermined level, and the entire apparatus was large.

[Means for Solving the Problems] Therefore, the present inventor has diligently studied in order to solve the above problems, provide good gas exchange, and provide a compact oxygenator as a whole, It has arrived.

That is, according to the present invention, a first inner cylinder having a central portion whose diameter is larger than both ends and a first outer cylinder are provided, and the first inner cylinder is provided between the first inner cylinder and the first outer cylinder. And the porous hollow fibers are arranged along the longitudinal axis direction of the first outer cylinder, and the first inner cylinder, the first outer cylinder, and the outer surface of the first outer cylinder and the inner surface of the first outer cylinder at the openings at both ends of the hollow fiber. And a gas exchange section in which the outer surface of the hollow fiber is airtightly supported by a support member, a second inner cylinder and a second outer cylinder are provided, and a heat exchange tube is provided between the second inner cylinder and the second outer cylinder. A heat exchanger integrated artificial lung comprising a heat exchange part integrally provided outside the gas exchange part, which is provided on the end of the first outer cylinder of the gas exchange part. The blood is flown to the outside of the hollow fiber through the blood inlet, and oxygen is introduced into the hollow portion of the hollow fiber for gas exchange, and then the gas-exchanged blood is passed through the passage provided at the end of the first inner cylinder. It is introduced into the heat exchanging part by the mouth, blood is stored between the second inner cylinder and the second outer cylinder of the heat exchanging part, and the heat is exchanged and discharged while passing the outside of the heat exchanging tube. There is provided a heat exchanger-integrated lung.

[Operation] The blood flowing outside the hollow fiber passes through the passage port (blood outflow hole) provided at the end of the first inner cylinder of the gas exchange section to form the second inner cylinder and the second outer cylinder of the heat exchange section. It is temporarily stored in between. A heat exchange tube is built in between the second inner cylinder and the second outer cylinder of the heat exchange section, and blood flows outside the heat exchange tube.

Thus, once the blood is stored between the second inner cylinder and the second outer cylinder of the heat exchange section, the blood introduced from the blood introduction port provided at the end of the first outer cylinder flows outside the hollow fiber. At this time, the blood flows toward the center, so that the blood and oxygen gas are brought into good contact with each other.

In addition, since the blood slowly flows outside the heat exchange tube provided between the second inner cylinder and the second outer cylinder of the heat exchanger, heat exchange is sufficiently performed and the blood is kept at a predetermined temperature. Be drunk

[Examples] The present invention will be described below based on examples shown in the drawings.

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

The artificial lung of the present embodiment is composed of a gas exchange section I and a heat exchanger II integrally disposed on the gas exchange section I.

Reference numeral 1 is a blood inlet for introducing blood A, and an outer cylinder 2
It is provided at the bottom of. A large number of porous hollow fibers 4 are arranged between the outer cylinder (first outer cylinder) 2 of the gas exchange section I and the inner cylinder (first inner cylinder) 3 of the gas exchange section I, At both ends of the first outer cylinder 2, the first inner cylinder 3 and the porous hollow fiber 4, the inner surface of the first outer cylinder 2, the outer surface of the first inner cylinder 3 and the outer surface of the porous hollow fiber 4 Are airtightly supported by the adhesive (supporting member) 5. An inlet 6 for oxygen gas B is provided at the lower end of the porous hollow fiber 4, and an exchanged gas outlet 7 is provided at the upper end of the porous hollow fiber 4.

Here, the diameter of the central portion of the first inner cylinder 3 is larger than the diameters of both end portions thereof, that is, the central portion has a convex shape.
The packing density of the porous hollow fibers 4 arranged between the first outer cylinder 2 and the first inner cylinder 3 becomes lower toward the ends.

On the other hand, a heat exchange tube 8 for keeping blood at a predetermined temperature is provided between the inner cylinder (second inner cylinder) 12 and the outer cylinder (second outer cylinder) 11 of the heat exchange section II. Has been.

In the above configuration, the blood A enters the artificial lung gas exchange part I through the blood inlet 1, and then the porous hollow fiber 4 arranged between the first outer cylinder 2 and the first inner cylinder 3. Flows down the outside of the. At this time, the blood A comes into contact with the oxygen gas fed into the hollow portion of the porous hollow fiber 4 through the oxygen gas inlet 6 through the pores formed in the porous hollow fiber 4 to exchange gas. To do. The blood A is then guided to the inside of the first inner cylinder 3 from a predetermined number of passage ports 9 provided in the circumferential direction in the upper part of the first inner cylinder 3 of the gas exchange section I, where the blood is temporarily stored. To be done. As described above, the blood is guided toward the inside of the first inner cylinder 3 through the passage port 9 while rising toward the center from the blood introduction port 1 and is temporarily stored. As a result, the outer surface of the high-quality hollow fiber 4 is evenly contacted, and the gas exchange with the oxygen gas passing through the hollow part of the hollow fiber 4 is sufficiently and satisfactorily performed. The diameters and numbers of the passage openings 9 provided in the circumferential direction of the first inner cylinder 3 are the diameters of the inner cylinder and the outer cylinder,
Although it depends on the length and the like, it is necessary to provide at least the blood so that it can evenly contact the porous hollow fiber. Normally, the diameter is 1 to 15 mm (φ) and the pitch is 2 to 90
formed in mm.

The blood that has flowed into the inner cylinder 3 flows upwardly outside the heat exchange tube 8 provided between the second inner cylinder 12 and the second outer cylinder 11 of the heat exchange section II to exchange heat. The heat is exchanged with the medium C flowing in the tube 8, the temperature of the medium C is regulated, and the medium C is discharged from the blood outlet 10.

The arrangement shape of the heat exchange tube 8 provided between the second inner cylinder 12 and the second outer cylinder 11 of the heat exchange section II is not particularly limited, but a spiral shape or a spiral shape has a contact area. This is preferable because it can be increased and the heat exchange efficiency is improved. Also,
It is preferable to provide the convex portion 15 in a spiral shape as shown in FIG. 2 on the outer peripheral surface of the tube 8 because the contact area can be similarly increased.

The material of the heat exchange tube 8 is not particularly limited, and any material having a large heat transfer coefficient can be used. For example, 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 4 disposed between the first outer cylinder 2 and the first inner cylinder 3, a polyolefin resin such as polypropylene or polyethylene, polyvinylidene fluoride,
A fluororesin such as ethylene tetrafluoroethylene copolymer or a hydrophobic resin such as silicone resin is preferably used. Further, even when a material other than the hydrophobic resin is used, it is possible to use a material in which the contact surface with blood is treated with a silicone resin to make it hydrophobic.

The porous hollow fiber 4 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 4 has a porosity of about 20 to 80%.

In addition, the membrane area of the porous hollow fiber 4 is usually 3 m ² or less,
It can be made smaller than conventional commercial products. This is because the hollow fiber has a large porosity and the blood and oxygen gas are sufficiently contacted with each other as described above, which is a great advantage of the present invention.

As described above, the diameter of the central portion of the first inner cylinder 3 is made larger than the diameters of both end portions thereof, so that the first inner cylinder 3 is disposed between the first outer cylinder 2 and the first inner cylinder 3. The packing density of the porous hollow fibers 4 becomes lower toward the ends, and the packing density is usually 0.3 to 0.5 at both ends and 0.4 to 0.7 at the central part.

In the above embodiments, an example of a vertical type heat exchanger-integrated oxygenator was shown, but other horizontal type may also be used, and the arrangement of the blood inlet and the gas inlet is reversed. Can also be used.

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

(Example) A heat exchanger-integrated artificial lung having the configuration shown in FIG. 1 and having the following dimensions and conditions were used.

First inner cylinder ... Diameter (both ends: 54 mm (φ), central part: 64 mm
(Φ)] First outer cylinder… 80 mm diameter Second inner cylinder… 65 mm diameter Second outer cylinder… 80 mm diameter Overall length… 220 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% Support member (potting material) ... Polyurethane resin heat exchange tube ... Thickness 1 mm, diameter 10 mm (φ) The pipe is made of aluminum with epoxy coating, and is arranged spirally inside the inner cylinder. A convex portion as shown in FIG. 2 is formed on the outer peripheral surface of the tube.

In the above, when the oxygen gas addition ability and the carbon dioxide exchange ability with respect to bovine blood (hematocrit value 40%, hemoglobin amount 12 ± 1 g / dl) were measured, as shown in FIGS. 3 and 4, blood amount 1.0, The amount of oxygen gas added at 2.0 and 3.0 (/ min) is 58, 84 and 102 (ml / min) respectively, and the amount of carbon dioxide gas removed is 1.0, 2.0 and 3.0 (/ min) when the blood flow is 50, 80, 95 (ml) at a flow rate of 1 (/ min)
/ min), blood flow 2 (/ min) 70, 100, 120 (ml)
/ min), indicating sufficient gas exchange performance.

[Effects of the Invention] As described above, according to the heat exchanger-integrated artificial lung of the present invention, since blood comes into uniform contact with the outer portion of the porous hollow fiber, there is sufficient blood and oxygen gas. Since they are in good contact with each other, good gas exchange can be performed, and since the gas exchange section and the heat exchanger are integrally provided, the whole artificial lung can have an extremely compact structure.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a heat exchanger-integrated artificial lung of the present invention, FIG. 2 is a partial explanatory view showing a part of a heat exchange tube, and FIGS. 3 and 4 are oxygen. It is a graph which shows gas addition ability and carbon dioxide exchange ability. 1 ... Blood inlet, 2 ... First outer cylinder of gas exchange section, 3
...... First inner cylinder of gas exchange part, 4 ... Porous hollow fiber, 5
...... Adhesive, 6 ... Oxygen gas inlet, 7 ... Exchange gas outlet, 8 ... Heat exchange tube, 9 ... Passage port, 10 ... Blood discharge port, 11 ... Second heat exchange section Outer cylinder, 12 ... second inner cylinder of heat exchanger, 13 ... heat exchange medium inlet, 14 ... heat exchange medium outlet, 15 ... convex portion.

Claims (1)

[Claims] Claim: What is claimed is: 1. A first inner cylinder having a central portion whose diameter is larger than both ends, and a first outer cylinder are provided, and the first inner cylinder and the first outer cylinder are provided between the first inner cylinder and the first outer cylinder. Porous hollow fibers are arranged along the longitudinal axis direction of the outer cylinder, and the outer surface of the first inner cylinder, the inner surface of the first outer cylinder, and the hollow fibers are formed at the openings of both ends of the first inner cylinder, the first outer cylinder and the hollow fiber. A gas exchange section whose outer surface is airtightly supported by a support member, a second inner cylinder and a second outer cylinder are provided, and a heat exchange tube is wound between the second inner cylinder and the second outer cylinder. A heat exchanger integrated oxygenator comprising a heat exchange part integrally provided outside the gas exchange part, wherein the blood introduction part is provided at a first outer tube end part of the gas exchange part. Oxygen is introduced into the hollow portion of the hollow fiber for gas exchange while blood is flown from the mouth to the outside of the hollow fiber, and then the gas-exchanged blood is passed through the passage opening provided at the end of the first inner cylinder. It is introduced into the exchange part, and the blood is stored between the second inner cylinder and the second outer cylinder of the heat exchange part, and the heat is exchanged and discharged while passing the outside of the heat exchange tube. Oxygenator with integrated heat exchanger.