JP2003010323A - Artificial lung - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial lung in which the movability of carbon dioxide can be controlled in the extracorporeal circulation of blood. SOLUTION: The artificial lung is provided with a gas flow rate adjusting member in the state of being closable at least partially at least at one open end of a bundle of hollow fiber membranes in the artificial lung.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an artificial lung. More specifically, the present invention relates to an oxygenator capable of controlling the carbon dioxide gas transfer ability of the oxygenator during extracorporeal circulation.

[0002]

2. Description of the Related Art The gas exchange capacity required for an artificial lung used for extracorporeal circulation includes oxygen addition capacity and carbon dioxide gas removal capacity. In recent years, the artificial lung has remarkably improved the ability to remove carbon dioxide as well as the ability to add oxygen. This is largely due to the design such that the blood and gas flow directions are opposite or orthogonal.

However, in actual extracorporeal circulation, although high oxygen addition ability is desired, high carbon dioxide gas removal ability is not required. Since the amount of carbon dioxide removed relative to the flow rate of gas blown to the oxygenator changes severely, it is necessary to control the gas flow rate in detail.
As a result, the burden on the extracorporeal circulation technologist increases.

In order to prevent this, there is an artificial lung whose carbon dioxide gas removing ability is kept low in advance. Since the sensitivity of the carbon dioxide gas removing ability to the flow rate of the blown gas is low, it is a means for facilitating the control of the carbon dioxide partial pressure by using such an artificial lung.

However, in such an artificial lung, it is essential that the blood and gas flows be in parallel flow, which cannot be realized in an artificial lung having a convective flow or a direct flow structure. Further, when the ability to exceed the carbon dioxide removing ability of the artificial lung is required, such as when the patient's carbon dioxide partial pressure is to be rapidly reduced, such as when the circulation is restarted, the response will be delayed.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a new artificial lung.

Another object of the present invention is to provide an oxygenator capable of controlling the carbon dioxide gas transfer ability of the oxygenator during extracorporeal circulation.

Still another object of the present invention is to reduce oxygen addition ability by providing a substance which becomes a gas flow resistance in a part of a carbon dioxide gas flow path in an artificial lung module which originally has sufficient carbon dioxide gas transfer ability. The object is to provide an artificial lung in which only the carbon dioxide gas transfer ability is reduced without causing the above.

Another object of the present invention is to remove the above-mentioned resistance by a simple operation when a high carbon dioxide gas removing ability is required,
An object of the present invention is to provide an artificial lung capable of exhibiting a sufficient carbon dioxide gas removing ability.

[0010]

The above various objects are achieved by the following items (1) to (6). (1) An oxygenator in which a gas flow rate adjusting member is at least partially occluded at least at one open end of a hollow fiber membrane bundle in the oxygenator. (2) The oxygenator according to (1), wherein the gas flow rate adjusting member is made of a porous material. (3) The artificial lung according to (2) above, wherein the porous material is a non-woven fabric or a foamed resin. (4) The artificial lung according to any one of (1) to (3) above, wherein the hollow fiber membrane bundle is provided on the outer peripheral portion of the tubular heat exchange layer. (5) An artificial lung part composed of a tubular core, a tubular hollow fiber membrane bundle consisting of a large number of hollow fiber membranes for gas exchange wound around the outer surface of the tubular core, and inside the tubular core. An artificial lung comprising a heat exchanger part housed therein and a housing for housing the oxygenator part and the heat exchanger part, wherein a gas flow rate adjusting member is provided at at least one open end of the hollow fiber membrane bundle. An artificial lung that is occluded at least partially. (6) The oxygenator according to (5), wherein the gas flow rate adjusting member is made of a porous material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an artificial lung according to the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view showing an example of an artificial lung according to the present invention, and FIG. 2 is a sectional view taken along line BB in FIG.

As shown in FIG. 1 and FIG. 2, the artificial lung 1 according to the present invention comprises a tubular core 5 and a tubular core 5 having a large number of hollow fiber membranes for gas exchange wound around the outer surface thereof. An artificial lung part composed of the hollow fiber bundles 3, a heat exchanger part accommodated in the tubular core 5, and a housing 2 accommodating the artificial lung part and the heat exchanger part.

The tubular core 5 has a groove 51 which forms a blood flow path between the outer surface of the tubular core 5 and the inner surface of the tubular hollow fiber membrane bundle 3,
First blood chamber 1 formed between the tubular core 5 and the heat exchanger section
There is an opening 52 for blood circulation that connects 1 and the groove 51.
The artificial lung 1 has a blood inflow port 24 communicating with the first blood chamber 11 formed between the tubular core 5 and the heat exchanger portion, and a first inflow port formed between the outer surface of the tubular hollow fiber membrane and the inner surface of the housing 2. A blood outflow port 25 that communicates with the second blood chamber 12 is provided.

In the hollow fiber membrane oxygenator 1 of this embodiment,
As shown in FIGS. 1 and 2, from the outside, the tubular housing body 21, the second blood chamber 12, the hollow fiber membrane bundle 3, and the groove 51 are arranged.
Or the first blood chamber 11, the tubular heat exchange body 31, the tubular heat exchange body deformation restricting portions 34 and 35, and the tubular heat medium chamber forming member 32 are arranged substantially concentrically in this order, or Has been formed.

The housing 2 has a tubular housing body 21 having a blood outflow port 25, a first header 22 having a gas inflow port 26, a heat medium inflow port 28 and a heat medium outflow port 29, a gas outflow port 27 and a tubular shape. The core 5 is provided with a second header 23 having an insertion port for a blood inflow port 24. First header 2
The inner surface of 2 is provided with a heating medium chamber forming member connecting portion 22a that projects in a tubular shape and a partitioning portion 22b that divides the inside of the tubular connecting portion 22a into two parts. Further, on the inner surface of the second header 23, the heat medium chamber forming member connecting portion 23 protruding in a cylindrical shape is formed.
a is provided. Therefore, as shown in FIG. 1, the tubular heat medium chamber forming member 32, which will be described later, is held at the open end side by the first header 22 and at the closed end side by the second header 2.
It is held at 3.

First, the artificial lung section will be described.

FIG. 3 is an explanatory view for explaining the internal structure of the artificial lung part of one embodiment of the artificial lung according to the present invention.
FIG. 4 is a left side view of a tubular core used in an embodiment of the hollow fiber membrane oxygenator of the present invention, and FIG. 5 is a right side view of the tubular core shown in FIG.

The artificial lung part comprises a tubular core 5 and a tubular hollow fiber membrane bundle 3 consisting of a large number of hollow fiber membranes wound around the outer surface of the tubular core 5.

As shown in FIGS. 6 and 1 to 5, the tubular core 5 is a tubular body, and a donut plate-like protrusion 55 extending inward with a predetermined width is formed at one end thereof. The blood inflow port 24 is formed on the outer surface of the flat surface of the donut plate-shaped protruding portion 55 so as to project outward in parallel to the central axis of the tubular core 5. On the outer surface of the tubular core 5, a large number of grooves 51 that form a blood flow path are formed between the outer surface of the tubular core 5 and the inner surface of the tubular hollow fiber membrane bundle 3. Further, the tubular core 5 has a blood circulation opening 52 that connects the groove 51, the tubular core 5, and the first blood chamber 11 formed between the tubular heat exchanger portion. The tubular core 5 has an outer diameter of 2
About 0 to 100 mm is suitable, and the effective length (the length of the portion not buried in the partition wall in the total length) is 10 to 730 m.
About m is preferable.

Specifically, the tubular core 5 has a plurality of grooves 51 which are parallel to each other and are not continuous except for both end portions thereof, and an annular rib 53 is provided between the grooves 51. The groove of the tubular core 5 is formed so as to extend over almost the entire portion of the hollow fiber membrane bundle that contributes to gas exchange (effective length, portion not buried in partition wall). The tubular core 5 used here is provided with a flat surface-shaped groove-unformed portion 54 that is substantially on the extension line of the blood inflow port 24 and extends over almost the entire groove 51-formed portion of the tubular core 5. Therefore, the groove 51 and the rib 53 of the tubular core 5 are an annular groove 51 (arc-shaped groove 51) having a start end and an end, and an annular rib 53 (arc-shaped rib).

Further, the blood inflow port 24 is formed by the tubular core 5
The blood circulation opening 52 is provided on one end side of the
Are formed in a region facing a region where the center line of the blood inflow port 24 is extended. By doing so, the blood circulation form in the first blood chamber 11 formed between the tubular core and the heat exchanger portion is likely to be uniform, and the heat exchange efficiency is also high.

The hollow fiber membrane bundle 3 is wound around the outer surface of the cylindrical core 5 described above. As shown in FIG. 6, the hollow fiber membranes 3a forming the hollow fiber membrane bundle 3 are wound around the tubular core 5 in sequence, so that the hollow fiber membrane layers spreading on the outer peripheral surface of the tubular core 5 have a multi-layer structure. In other words, it is in a state of being overlapped with each other, in other words, being overlapped in a spiral shape, or being wound in a reel shape with a tubular core as a core. Further, the hollow fiber membrane layer is provided with an intersecting portion 3b where the hollow fiber membranes 3a intersect in the vicinity of the center in the longitudinal direction of the tubular core 5, and the intersecting portion (crosswind portion) 3b is positioned depending on the portion of the hollow fiber membrane layer. Are different. By changing the positions of the intersecting portions in this way, as shown in FIG. 6, the intersecting portions in the overlapping layers do not overlap each other, and a blood short circuit due to the overlapping of the intersecting portions can be prevented. The intersecting portion is formed continuously by alternately intersecting, for example, 2 to 6 hollow fiber membranes that are wound substantially in parallel.

In this embodiment, the position of the intersecting portion 3b is different depending on the location of the hollow fiber membrane layer so that another intersecting portion does not directly overlap the intersecting portion. In other words,
If the direct intersecting portions do not overlap, the positions of the intersecting portions may indirectly overlap with each other through the non-overlapping intersecting portions (in other words, the hollow fiber membrane layers). Specifically, as shown in FIG. 7 that illustrates a state in which the hollow fiber membrane bundle (hollow fiber membrane layer) is expanded, the position of the intersection 3b is continuous with the center in the longitudinal direction of the hollow fiber membrane bundle as the center. Are changing. Each layer shown in FIG. 6 is a hollow fiber membrane layer that goes around the core of the hollow fiber membrane bundle, and is laminated in the order of N + 1 layer on N layer. Then, in this example, the position of the intersecting portion 3b continuously changes so that a total of eight layers from the N layer to the N + 7 layer forms one set, and thereafter, the position is repeated. The number of sets is
Although it depends on the membrane area of the artificial lung, about 3 to 40 sets are general, and the number of layers is about 3 to 40 in general.

In this example, the intersecting portion 3b, which was located approximately at the center in the longitudinal direction of the hollow fiber membrane bundle at the beginning of the N layer, gradually moved to one end side (right side) of the hollow fiber membrane bundle, and the end of the N + 1 layer. (In other words, at the beginning of the N + 2 layer), the state is the one that has moved to the most end side (right side). Then, again, the intersecting portion moves to the center of the hollow fiber membrane bundle in the longitudinal direction, and at the end of the N + 3 layer (in other words, the beginning of the N + 4 layer), it is in the same position as the initial position of the N layer in the longitudinal direction of the hollow fiber membrane bundle. Located in the center. The intersection at the beginning of the Nth layer and the intersection at the beginning of the N + 4th layer are N +
Overlapping through layers 1, N + 2 and N + 3, but not directly. Subsequently, the intersecting portion moved to the other end side (left side) in the longitudinal direction of the hollow fiber membrane bundle, and moved to the other end side (left side) at the end of the N + 5 layer (in other words, the beginning of the N + 6 layer). It becomes a state. Then, again, the intersecting portion shifts to the central direction in the longitudinal direction of the hollow fiber membrane bundle, and at the end of the N + 7 layer, it is located in the central position in the longitudinal direction of the hollow fiber membrane bundle, which is the same position as the initial position of the N layer. Intersection and N + at the beginning of N + 4 layer
At the end of the 7th layer (then the beginning of the Nth layer), the intersection is N + 5th layer, Nth layer.
Overlapping via +6 and N + 7 layers, but not directly.

The hollow fiber membrane bundle is formed by winding one or a plurality of hollow fiber membranes at the same time and winding the hollow fiber membranes around the tubular core so that all the hollow fiber membranes have substantially constant intervals. There is. The distance between the hollow fiber membranes and the adjacent hollow fiber membranes that are substantially parallel to each other is preferably 1/10 to 1/1 of the outer diameter of the hollow fiber membranes.

In the hollow fiber membrane bundle in which the position of the intersecting portion moves as described above, one or a plurality of hollow fiber membranes at the same time and all the adjacent hollow fiber membranes have substantially constant intervals. It is formed by spirally winding the tubular core, and a tubular core rotating means 61 and a hollow fiber membrane for rotating the tubular core when the hollow fiber membrane is wound around the tubular core. The winder device 62 for weaving the

[0028]

[Equation 1]

When the center of the longitudinal direction of the cylindrical core rotating means 61 and the winder device 62 is 0 with respect to the axial direction of the cylindrical core, it moves from -40 to +40 mm.
It can be formed by being wound around the tubular core by continuous relative movement within a range of, preferably within a range of −30 to +30 mm, particularly preferably within a range of −15 to +15 mm.

The relative movement of the tubular core rotating means and the tubular core of the winder device relative to the axial direction is such that the tubular core rotating device is fixed and only the winder device is moved, or the winder device is fixed and only the tubular core rotating device. May be either moving or both moving.

Note that n, which is the relationship between the number of revolutions of the winding rotor and the number of winder reciprocations, should be 1 to 5, and is preferably 1. In this way, by selecting an integer as n in the above formula 1, one hollow fiber membrane intersecting portion (crosswind portion) is formed near the center in the longitudinal direction of the hollow fiber membrane bundle. In the artificial lung 1 of this example, N = 2 is used, and in this case, the hollow fiber membrane bundle 3 wound around the outer surface of the tubular core 5 (before cutting both ends) intersects near the center. The part 3b is formed.

A porous gas exchange membrane is used as the hollow fiber membrane. The porous hollow fiber membrane has an inner diameter of 100 to 10
00 μm, wall thickness 5-200 μm, preferably 10-1
00 μm, porosity 20 to 80%, preferably 30 to 6
0%, and the pore size is 0.01 to 5 μm, preferably 0.1.
Those having a size of 01 to 1 μm can be preferably used. As the material used for the porous membrane, a hydrophobic polymer material such as polypropylene, polyethylene, polysulfone, polyacrylonitrile, polytetrafluoroethylene, or cellulose acetate is used. Polyolefin resins are preferable, and polypropylene is particularly preferable, and those in which fine pores are formed in the wall by a stretching method or a solid-liquid phase separation method are more preferable. The outer diameter of the hollow fiber membrane bundle 3 is
30 to 162 mm is suitable, and the thickness of the hollow fiber membrane bundle 3 is preferably 3 mm to 28 mm. further,
The tubular hollow fiber membrane bundle 3 formed on the outer surface of the tubular core 5 has a filling rate of the hollow fiber membrane in the tubular space formed between the outer surface and the inner surface of the tubular hollow fiber membrane bundle 3 of 50. % To 75% is preferable. More preferably, 53% to 73%
Is.

After the hollow fiber membrane bundle 3 is wound around the tubular core 5, both ends are fixed to the tubular housing body 21 by the partition walls 8 and 9, and both ends of the hollow fiber membrane bundle 3 are fixed. Is disconnected. The hollow fiber membrane bundle produced by the hollow fiber membrane bundle forming device as described above has different traverse positions depending on the layers, and therefore both end portions are not aligned. For this reason, it is necessary to cut both ends of the formed hollow fiber membrane bundle at the portions where all the layers overlap. There is a hollow fiber membrane whose ends do not open unless it is cut at the portion where all layers overlap.

Both ends of the tubular core 5 around which the hollow fiber membrane bundle 3 is wound around the outer surface are liquid-tightly fixed to both ends of the tubular housing main body 21 by the partition walls 8 and 9 to form an outer surface of the tubular hollow fiber membrane. An annular space (cylindrical space) between the inner surfaces of the cylindrical housing body 21.
A second blood chamber 12 is formed. The blood outflow port 25 formed on the side surface of the cylindrical housing body 21 communicates with the second blood chamber 12. The partition walls 8 and 9 are formed of a potting material such as polyurethane or silicone rubber.

Then, as shown in FIG. 3, a heat exchanger section, which will be described later, is housed inside the tubular core 5 of the artificial lung section formed as described above. An annular first blood chamber 11 is formed between the tubular core and the tubular heat exchanger portion, and the blood inflow port 24 communicates with this blood chamber 11.

As shown in FIGS. 1 and 2, the tubular heat exchanger portion includes a tubular heat exchange body 31, a tubular heat medium chamber forming member 32 housed in the heat exchange body 31, and a tubular body. Heat exchanger 3
It is provided with two cylindrical heat exchanger deformation restricting portions 34 and 35 which are inserted between 1 and the cylindrical heat medium chamber forming member 32.

As the cylindrical heat exchange element 31, a so-called bellows type heat exchange element is used. Bellows type heat exchanger 31
As shown in FIG. 1, the (bellows tube) is a bellows forming portion including a large number of hollow annular projections formed substantially parallel to a central side surface, and a cylindrical portion formed at both ends thereof and having an inner diameter substantially equal to that of the bellows forming portion. 31c is provided. One of the cylindrical portions of the heat exchange body 31 is sandwiched between the inner surface of the end portion of the hollow tubular core 5 on the blood inflow port 24 side and the second header 23, and the heat exchange body 3
The other one of the cylindrical portions of 1 is inserted between the ring-shaped heat exchange element fixing member 48 inserted in one end of the hollow cylindrical core 5 and the ring-shaped heat exchange element fixing member 48 and the first header 22. Tubular heat exchanger fixing member 49 and first header 22
It is sandwiched between the spaces.

The bellows type heat exchange element 31 is made of stainless steel,
It is formed into a so-called fine bellows shape from a metal such as aluminum or a resin material such as polyethylene or polycarbonate. Metals such as stainless steel and aluminum are preferable in terms of strength and heat exchange efficiency. In particular, it is composed of a corrugated bellows tube in which a large number of irregularities substantially orthogonal to the axial direction (center axis) of the tubular heat exchange element 31 are repeated, and the heights of the valleys and peaks are 5.0. Approximately 15.0 mm is the most efficient, and preferably 9.0 to 12.0 mm. The axial length of the heat exchanger portion varies depending on the patient to be used, but a length in the range of 10 to 730 mm is used.

As shown in FIGS. 1 and 2, the tubular heat medium chamber forming member 32 is a tubular body having an opening at one end (on the side of the first header 22), and the inside thereof serves as the inflow side heat medium chamber 41. A partition wall 32a which is divided into the outflow-side heat medium chamber 42, a first opening 33a which communicates with the inflow-side heat medium chamber 41 and extends in the axial direction,
The second opening 33b communicates with the inflow side heat medium chamber 42 and extends in the axial direction. The second opening 33b faces the second opening 33b and is formed on a side surface at a position deviated by about 90 degrees from the first opening 33a and the second opening 33b, and protrudes outward. And projections 36a and 36b extending in the axial direction. The protrusion 36a penetrates into an axially extending groove formed in the center of the inner surface of the heat exchange body deformation restricting portion 34 to restrict the movement of the deformation restricting portion 34. Similarly, the protrusion 36b restricts the movement of the deformation restricting portion 35 by penetrating into the axially extending groove formed in the center of the inner surface of the heat exchanger deformation restricting portion 35.

When the open end side of the tubular heat medium chamber forming member 32 is fitted into the heat medium chamber forming member connecting portion 22a of the first header 22, as shown in FIG. The partition portion 22b that divides the inside of the tubular connection portion 22a into two halves is in close contact with one surface (the lower surface in this embodiment) of the tip portion of the partition wall 32a of the forming member 32. As a result, the inflow-side heat medium chamber 41 inside the tubular heat-medium chamber forming member 32 communicates with the heat medium inflow port 28, and the outflow side heat medium chamber 42 communicates with the heat medium outflow port 29.

Further, the two heat exchanger deformation restricting portions 34, 3
5 is provided with a notch portion extending in the axial direction at each end portion to be associated with each other, and two restriction portions 34 and 35 are provided.
As shown in FIG. 2, the medium inflow side passage 37 and the medium outflow side passage 38 are formed by abutting each other. The two heat exchanger deformation restricting portions 34 and 35 may be integrally formed.

The flow of the heat medium in the heat exchanger section of the artificial lung 1 of this embodiment will be described with reference to FIGS. 1 and 2. The heat medium that has flowed into the artificial lung from the heat medium inflow port 28 passes through the inside of the first header 22 and flows into the inflow side heat medium chamber 41. Then, the tubular heat medium chamber forming member 3
2 inflow chamber side opening 33a and heat exchange body deformation restricting portion 3
Medium inflow side passage 37 formed by abutting portions of 4, 35
Through the heat exchange body 31 and the heat exchange body deformation restricting portion 34,
It flows through 35. At this time, the heat exchanger 31 is heated by the heat medium.
Is heated or cooled. Then, the heat medium passes through the medium outflow side passage 38 formed by the contact portions of the heat exchange body deformation restricting portions 34 and 35 and the outflow chamber side opening 33b of the tubular heat medium chamber forming member 32, thereby The heat medium chamber forming member 32 flows out into the outflow side heat medium chamber 42. Then, it passes through the inside of the first header 22 and flows out from the heat medium outflow port 29.

In this artificial lung 1, the blood flowing in from the blood inflow port 24 flows into the blood guiding portion 56 which constitutes a part of the blood chamber 11 between the tubular core 5 and the tubular heat exchanger portion. After flowing between the tubular core 5 and the tubular heat exchange body, it flows out of the tubular core 5 through the opening 52 formed at a position facing the first blood guiding portion 56. The blood flowing out from the tubular core 5 flows into the plurality of grooves 51 formed on the outer surface of the tubular core 5 located between the inner surface of the hollow fiber membrane bundle 3 and the tubular core 5, and then the hollow fiber membrane bundle 3 Flows in between. In the artificial lung of this example, the portion of the hollow fiber membrane bundle 3 that contributes to gas exchange (effective length,
Since a large number of grooves 51 are formed so as to extend over almost the entire area (part not buried in the partition wall), blood can be dispersed throughout the hollow fiber membrane bundle 3 and the entire hollow fiber membrane bundle can be effectively used. , The gas exchange capacity is also high. Then, after coming into contact with the hollow fiber membrane and undergoing gas exchange, it flows into the second blood chamber 12 formed between the tubular housing body 21 and the outer surface of the hollow fiber membrane (outer surface of the hollow fiber membrane bundle 3), Outflow port 2
Outflow from 5. The oxygen-containing gas that has flowed in through the gas inflow port 26 flows through the first header 22 into the hollow fiber membrane from the partition wall end surface, passes through the second header 23, and flows out through the gas outflow 27.

As the material for forming the tubular housing body 21, the tubular core 5, the first and second headers 22 and 23, and the other heat exchanging elements 31, polyolefin (eg, polyethylene, polypropylene), Ester resin (eg polyethylene terephthalate), styrene resin (eg polystyrene, MS resin, MBS)
Resin), polycarbonate, etc. can be used.

Furthermore, the blood contact surface of the artificial lung 1 is preferably an antithrombotic surface. The antithrombogenic surface is
It can be formed by coating the surface with an antithrombotic material and then fixing it. As the antithrombotic material, heparin, urokinase, hydroxyethyl methacrylate-styrene-hydroxyethyl methacrylate, poly (hydroxyethyl methacrylate) and the like can be used.

Then, inside the artificial lung according to the present invention (for example, the space between the first header 22 and the hollow fiber bundle 3),
A gas flow rate adjusting member 85 that is at least partially occludable with respect to the open end of the hollow fiber bundle 3 is provided. A knob 86 is attached to the gas flow rate adjusting member 85. When the knob 86 is pressed, the gas flow rate adjusting member 85 contacts the open end of the hollow fiber membrane bundle 3, and when the knob 86 is pulled, the gas flow rate adjusting member 85 is adjusted. The member 85 separates.

The gas flow rate adjusting member 85 is usually made of a porous material, for example, non-woven fabric, foamed resin such as polyurethane foam, or the like.

However, the gas flow rate adjusting member 85 may be provided in the first header 22 on the gas inflow port 26 side, or the second header 23 on the gas outflow port 27 side.
It may be provided inside or both of the headers 22 and 23.

Next, a method for gas exchange using the artificial lung according to the present invention will be described.

As shown in FIGS. 1 and 2, the blood flowing in from the blood inflow port 26 is heat-exchanged by the heat medium flowing in from the heat medium inflow port 28 while passing through the tubular heat exchanger 31. After adjusting the temperature to a predetermined temperature, gas exchange between the gas passing through the hollow fiber membrane bundle 3 and introduced through the gas inflow port 26 and oxygen and carbon dioxide through the hollow fiber membrane is performed, Then, the blood is discharged from the blood outflow port 25 to the outside of the system.

The heat medium flowing from the heat medium inflow port 28 into the heat medium chamber 41 on the inflow side is heated by the heat medium chamber forming member connecting portion 33.
After passing through a and passing through the cylindrical heat exchange body 31 to exchange heat, the heat medium chamber forming member connecting portion 33b is passed to flow into the outflow side heat medium chamber 42, and then from the heat medium outflow port 29 to the system. It is discharged outside.

From the gas inlet port 26 to the first header 2
The gas introduced into 2 passes through the hollow fiber membrane from the open end of the hollow fiber membrane bundle 3, during which gas exchange is carried out between carbon dioxide in blood and oxygen in the gas. At this time,
The amount of gas supplied can be controlled by adjusting the degree of pressing of the knob 86.

Next, specific examples and comparative examples of the artificial lung according to the present invention will be described.

Example As the cylindrical housing body, the outer diameter is 144 mm and the inner diameter is 1
The one having a length of 09 mm and a length of 114 mm was used. Also, the first
As the header and the second header, those having a shape as shown in FIG. 1 were used.

The bellows type heat exchanger has an outer diameter of 75.
mm, inner diameter 50 mm, length 114 mm, length of bellows forming portion 90 mm, number of peaks 40, pitch of bellows (peaks) 2.2
A 5 mm one was used. Then, a tubular heat medium chamber forming member having a shape as shown in FIG. 1 and having a tubular portion outer diameter of 40 mm, a rib portion outer diameter of 44 mm, and a length of 90 mm is closed in the bellows type heat exchange body. , 90m outside this
m, and the maximum diameter portion of 49.5 mm, a combination of two heat exchange element deformation regulating members was inserted.

The tubular core has a shape as shown in FIGS. 3 to 6, and has a length of 114 mm, an outer diameter of 84 mm and an inner diameter of 7 mm.
6 mm, groove forming portion length 90 mm, groove depth is height 2.
5 mm, groove spacing 4 mm, rib top flat surface width 1 mm,
The one having 22 grooves on the outer circumference was used. Then, the bellows type heat exchanger was inserted into the tubular core.

On the outer surface of the cylindrical core, four porous polypropylene hollow fiber membrane bundles having an inner diameter of 195 μm, an outer diameter of 295 μm and a porosity of about 35% were rewound with the hollow fiber membrane spacing kept at 100 μm, and then adjacent to each other. The spacing between the hollow fiber membranes and the hollow fiber membranes is also the same as the previously wound hollow fiber membranes, and the hollow fiber membranes are wound so that the spacing between adjacent hollow fiber membranes is constant, and a flow path regulating plate is provided. A hollow fiber membrane bobbin with a built-in heat exchanger was also manufactured. When the hollow fiber membrane is wound on the tubular core, the rotating body for rotating the tubular core and the winder for weaving the hollow fiber membrane are moved by the following formula, and the winder continuously moves in a small amount in the axial direction. As shown in FIG. 7, all the 12 sets are moved by changing the position width of the intersection within ± 2.5 mm so that one set is composed of 8 layers.
A hollow fiber membrane bundle having 18 layers and a filling rate of 68% was produced.

[0058]

[Equation 2]

Then, both ends of the bundle of hollow fiber membranes are fixed to both ends of the tubular housing body together with the tubular core by potting materials, and are rotated around the heat exchanger portion without cutting the heat exchanger portion. Both ends of the fixed hollow fiber membrane bobbin were cut. Further, as shown in FIG. 1, the knob 86 is provided in the space on the first header side provided with the gas inflow port.
The gas flow rate adjusting member 85 made of a non-woven fabric connected to the above was provided so as to come into contact with the open end of the hollow fiber bundle 3. Then, an artificial lung having a membrane area of 2.5 m ² and a blood filling amount of 250 ml having a structure as shown in FIGS. 1 and 2 is prepared by attaching the above-mentioned first header and second header to both ends of the tubular housing body. It was made. Note that the gas flow rate adjusting member was set to 52% closed state as Example 1, and the 25% closed state was set to Example 2.

Comparative Example An artificial lung similar to that of Example 1 was prepared except that a gas flow rate adjusting member was not provided. This was designated as Comparative Example 1. Further, in the same artificial lung as in Example 1, except that the gas flow rate adjusting member was made of silicone rubber,
A similar artificial lung was created. In addition, the gas flow rate adjusting member 5
A 2% closed state was set as Comparative Example 2, and a 25% closed state was set as Comparative Example 3. (Experiment) With respect to the artificial lungs of Examples 1 and 2 and Comparative Examples 1 to 3 produced as described above, the following experiment was performed using bovine blood for the closed state of the gas flow rate adjusting member. In addition, cow blood is AAMI (Association)
for the Advance of Medic
Standard venous blood as defined by Al Instrumentation) was used, and the artificial lungs were perfused with standard venous blood at flow rates of 2, 4, 6 and 8 liters / min, respectively. Then, for each artificial lung, blood is collected near the blood inflow port and the blood outflow port, and the oxygen gas partial pressure, carbon dioxide partial pressure, pH, etc. are obtained by the blood gas analyzer, and the blood flow rate and the carbon dioxide transfer amount are calculated. And the relationship between the blood flow rate and the oxygen transfer amount were obtained, and the graphs shown in FIGS. 8 to 11 were obtained.

[0061]

As described above, in the artificial lung according to the present invention, the flow rate adjusting member is occluded at least partially at the open end of at least one hollow fiber membrane bundle in the artificial lung. Therefore, by partially varying the oxygen gas flowing into the hollow fiber membrane, there is an advantage that only the carbon dioxide gas removing ability can be controlled without lowering the oxygen adding ability. That is, when the gas flow rate adjusting member made of non-woven fabric, foam or the like is partially installed near the end face of the hollow fiber membrane bundle, it becomes difficult for the gas to flow only to the fiber portion masked by it. Since the amount of carbon dioxide removed depends on the flow rate of the flowing gas, the ability to remove carbon dioxide in the whole artificial lung is suppressed. On the other hand, the oxygen addition ability depends on the oxygen gas concentration rather than the gas flow rate, and therefore hardly decreases.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an artificial lung according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is an explanatory diagram for explaining the internal structure of the artificial lung part of the embodiment of the artificial lung according to the present invention.

FIG. 4 is a left side view of a tubular core used in an embodiment of the artificial lung according to the present invention.

5 is a right side view of the tubular core shown in FIG.

FIG. 6 is an explanatory view showing a state where the housing of the artificial lung shown in FIG. 1 is partially peeled off.

FIG. 7 is an explanatory diagram for explaining an intersecting portion of an example hollow fiber membrane bundle used in the artificial lung according to the present invention.

FIG. 8 is a graph showing the disclosure of blood flow rate and carbon dioxide transfer rate when using the artificial lungs of Examples and Comparative Examples.

FIG. 9 is a graph showing the disclosure of blood flow rate and oxygen transfer rate when the artificial lungs of Examples and Comparative Examples were used.

FIG. 10 is a graph showing the disclosure of the blood flow rate and the carbon dioxide transfer amount when the artificial lung of the comparative example is used.

FIG. 11 is a graph showing the disclosure of the blood flow rate and the oxygen transfer amount when the artificial lung of the comparative example is used.

[Explanation of symbols]

1 artificial lung 2 housing 3 Cylindrical hollow fiber membrane bundle 3a hollow fiber membrane 3b intersection 5 tubular core 11 First blood chamber 12 Second blood chamber 21 Tubular housing body 22 First Header 23 Second Header 24 Blood inflow port 25 Blood outflow port 26 Gas inflow port 27 Gas outflow port 28 Heat medium inflow port 29 Heat medium outflow port 31 Cylindrical heat exchanger 34,35 Cylindrical heat exchanger deformation restriction part 51 groove 52 Blood circulation opening 85 Gas flow rate adjusting member 86 knobs.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4C077 AA03 BB06 DD25 HH07 HH15                       JJ06 JJ16 KK11 LL05 NN10                       PP03 PP08 PP10 PP14 PP15                       PP16

Claims (3)

[Claims] 1. An oxygenator in which a gas flow rate adjusting member is at least partially occludably provided at at least one open end of a hollow fiber membrane bundle in the oxygenator. 2. The artificial lung according to claim 1, wherein the gas flow rate adjusting member is made of a porous material. 3. The artificial lung according to claim 2, wherein the porous material is a non-woven fabric or a foamed resin.