JPH0622613B2 - Membrane oxygenator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a membrane oxygenator used in an extracorporeal blood circulation circuit.

[Prior Art] Conventionally, a membrane oxygenator has been used in an extracorporeal circulation circuit, and further, blood in the extracorporeal circulation is stored in the extracorporeal circulation circuit and removed when air bubbles flow in. In case the circulating blood volume is reduced due to a broken circuit tube or the like, a blood storage tank for storing blood is provided. Blood reservoirs include closed-type blood reservoirs made of a soft material and open-type blood reservoirs made of a hard material.The open-type blood reservoirs allow easy priming and confirmation of the amount of blood stored. It is widely used because it is possible to realize a blood reservoir with a large capacity, and it is easy to detect a blood storage amount using an ultrasonic wave transmitting and receiving device or a light emitting element and a light receiving element. In addition, it has the advantage that it can be easily integrated with the artificial lung and the circuit configuration can be simplified by making it integral, and it is also easy to remove bubbles during circuit setup and priming. Has been proposed (Japanese Patent Laid-Open No. 59-56661).

The artificial lung has a blood reservoir integrated with it, and causes the artificial lung to perfuse blood by the drop between the human body and the artificial lung. It has been desired to develop a membranous oxygenator that can more safely use blood because the blood can be perfused into the oxygenator due to the drop between the human body and the oxygenator more reliably.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems of the prior art, and allows the artificial lung to be reliably perfused with blood due to the difference between the human body and the artificial lung, and further It is to provide a membrane oxygenator that can be safely used.

[Means for Solving the Problems] What achieves the above object is a membrane oxygenator having a heat exchanger, a membrane oxygenator, and a blood reservoir, wherein the heat exchanger is a heat exchanger. A blood inlet provided in the lower part of the exchanger, and a blood outlet provided in the upper part of the heat exchanger, the membrane oxygenator is provided in the vertical direction, and a housing,
An assembly of hollow fiber membranes for gas exchange housed in the axial direction of the housing, a partition that holds both ends of the assembly of hollow fiber membranes in the housing in a liquid-tight manner, and communicates with the internal space of the hollow fiber membrane. The gas inflow part and the gas outflow part are provided in the lower part of the housing in the axial direction, and communicate with a blood chamber formed by the inner wall of the housing, the partition wall and the outer wall of the hollow fiber membrane, and further, the heat exchange. A blood inlet connected to a blood outlet of a container, and a blood outlet provided in an axially upper portion of the housing and communicating with the blood chamber,
The blood reservoir is a membrane having a blood inlet connected to the blood outlet of the membrane oxygenator, a blood reservoir communicating with the blood inlet, and a blood outlet provided below the blood reservoir. Type oxygenator.

The heat exchanger contains a large number of heat exchanging tubes therein, blood flows further outside the heat exchanging tubes, and a heat exchanging medium exists inside the heat exchanging tubes. It is preferably flowing. Further, it is preferable that the blood storage tank is formed of a transparent member. Further, it is preferable that the blood reservoir is provided between the blood inlet and the blood reservoir, and has a blood inflow portion communicating with the blood inlet and the blood reservoir. Further, it is preferable that a defoaming member is provided in the blood inflow portion so as to cross the blood flow path of the blood inflow portion. Further, the defoaming member is formed of urethane foam, for example. Further, it is preferable that the defoaming member is coated with a defoaming agent. Furthermore, the defoaming agent is, for example, silicone. Further, it is preferable that the blood storage tank has a communication portion that is provided above the blood storage tank and that connects the inside and the outside of the blood storage tank.

The membrane oxygenator of the present invention will be described in detail with reference to the embodiments shown in the drawings.

The membrane oxygenator of the present invention is a membrane oxygenator having a heat exchanger 15, a membrane oxygenator 1, and a blood reservoir 4, and the heat exchanger 15 is a lower portion of the heat exchanger 15. Blood inlet 16
And a blood outlet provided in the upper part of the heat exchanger 15,
The membrane oxygenator 1 includes a housing, an assembly of hollow fiber membranes 9 for gas heat exchange housed in the axial direction of the housing, and a partition wall that holds both ends of the assembly of hollow fiber membranes 9 in the housing in a liquid-tight manner. And a gas inflow portion 10 and a gas outflow portion 11 which communicate with the inner space of the hollow fiber membrane 9 and an inner wall of the housing and a partition wall and an outer wall of the hollow fiber membrane 9 which are provided in the lower portion in the axial direction of the housing. It communicates with the blood chamber and also has a heat exchanger.
It has a blood inlet 2 connected to the blood outlet 15 and a blood outlet 3 provided at the upper part of the housing in the axial direction, and the blood reservoir 4 is connected to the blood outlet 3 of the membrane oxygenator 1. The blood introducing port 12 is provided, the blood storing part 6 communicating with the blood introducing port 12, and the blood discharging port 8 provided in the lower part of the blood storing part 6.

First, the membrane oxygenator 1 will be described.

The membrane oxygenator 1 is for removing carbon dioxide in blood and adding oxygen.

The membrane oxygenator 1 shown in the drawings includes a housing, an assembly of hollow fiber membranes 9 axially housed in the housing, a partition wall that holds both ends of the hollow fiber membranes 9 in the housing in a liquid-tight manner, and a partition wall. Has a gas inflow portion 10 which is provided above and communicates with the internal space of the hollow fiber membrane 9, and a gas outflow portion 11 which is provided below the partition wall and communicates with the internal space of the hollow fiber membrane 9. A blood inlet 2 and a blood outlet 3 that communicate with a blood chamber formed by the partition wall, the inner wall of the housing, and the outer wall of the hollow fiber membrane are provided. The gas outflow portion 11 may open the lower partition wall and use the opening of the hollow fiber membrane 9 formed on the outer surface of the partition wall as the gas outflow portion.

In the membrane oxygenator of the present invention, the hollow fiber membrane 9 is used as described above.
Since it uses a type that allows blood to flow through the blood chamber formed by the outer wall of the housing, the inner wall of the housing, and the partition wall, there is little pressure loss, and it is necessary to install a blood pump in front of the membrane oxygenator in the circulation circuit. Therefore, blood can be sent to the membrane oxygenator and further to the blood reservoir by blood removal from the human body only by the difference between the human body and the membrane oxygenator.

A cardiotomy communication port 14 that communicates with the blood chamber of the artificial lung 1 is provided.

The cardiotomy communication port 14 is for communicating with a cardiotomy blood reservoir (not shown).

Next, the blood storage tank 4 will be described.

The blood reservoir 4 is composed of a housing forming a blood inlet 12, a blood inflow portion 5, a blood reservoir 6 and a blood outlet 8 and a lid 13 provided above the housing. The part is preferably transparent. This is because the stored blood can be easily confirmed.

Materials used for the blood storage tank 4 include hard vinyl chloride resin, styrene resin, and carbonate resin.

The blood storage tank 4 has a blood inlet 12 that communicates with the blood outlet 3 of the membrane oxygenator 1, and a blood reservoir 6 that communicates with the blood inlet 12, and blood is stored below the blood reservoir 6. A discharge port 8 is provided.

The blood reservoir 6 is a portion that stores blood. Further, above the blood storage tank 4, as a communication portion that connects the inside and the outside of the blood storage tank 4, the lid 13 is provided with a communication portion 20 that connects the inside and the outside of the blood storage tank 4. Further, the communication part is a lid 13
It may be formed by a gap between the housing and the housing.
It may be formed on the top of the housing.

The blood outlet 3 of the membrane oxygenator 1 and the blood inlet 12 are in fluid-tight communication. The blood outlet port 3 and the blood inlet port 12 are fitted in a liquid-tight manner or are bonded to each other using ultrasonic waves, high frequency waves or an adhesive so as to be in a liquid-tight manner.

The blood reservoir 4 has a blood inflow portion 5 which is located between the blood inlet 12 and the blood storage portion 6 and communicates with the blood inlet 12 and the blood storage portion 6. The defoaming member 7 is provided so as to cross the blood flow path of the blood inflow section 5. The blood inflow part 5 forms a blood flow path until the blood flowing in from the blood outlet 3 of the membrane oxygenator 1 enters the blood storage part 6, is located at a position higher than the blood storage part 6, and introduces blood. It has a mouth 12 and a bottom with almost no drop. The bottom surface may have a flat shape, a semi-cylindrical shape, or the like, but a flat shape is preferable because the defoaming member 7 described later can be easily installed.

Further, the blood inflow portion 5 is provided with a defoaming member 7 so as to cross the blood flow path, and the defoaming member 7 defoams when blood including bubbles flows and is free of bubbles. It is for sending blood to the blood reservoir 4.

Generally, a foam is used for the defoaming member 7, and the hydrophobic property is utilized to grow and remove bubbles. The foam refers to a mesh-like three-dimensional cube.

The defoaming member 7 should be in close contact with the bottom and side surfaces of the blood inflow portion 5 of the blood reservoir 4 so that all of the flowing blood comes into contact (so that a blood flow path that does not come into contact with the defoaming member is not formed). It is arranged.

The upper end of the defoaming member 7 does not necessarily have to be in close contact with the lid 13 of the blood reservoir 4, but in order to prevent movement of the defoaming member 7 and to prevent blood from flowing out from the upper end of the defoaming member 7. Are preferably in close contact with each other. Also, the defoaming member 7
Is preferably provided such that even when the maximum blood storage level of blood is stored in the blood storage tank 4, a part (preferably the upper part) thereof is in contact with air (atmosphere). It is possible to prevent the entire defoaming member from being buried in the blood and prevent bubbles from remaining in the defoaming member.

Further, a locking portion 21 is provided on the inner surface of the housing to prevent the defoaming member 7 from moving. The locking portions 21 are ribs formed on the inner surface of the housing, and a total of four locking portions 21 are provided, and the ends of the defoaming member 7 are sandwiched between the locking portions 21. The shape of the rib forming the locking portion 21 is preferably linear and continuous.

Further, a baffle plate 30 is provided in a portion facing the blood inlet 12. The baffle plate 30 is provided so as to cross the entire area of the blood inflow section 5.

This is for forming a blood storage space between the baffle plate 30 and the blood introduction port 12. By providing this storage space, it is possible to prevent air from entering the artificial lung 1 side from the blood reservoir 4 side, and the blood chamber side of the artificial lung 1 has a lower pressure than the oxygen chamber side (hollow fiber membrane inner surface side), It is possible to prevent air bubbles from flowing into the blood side through the hollow fiber membrane.

Next, the heat exchanger 15 attached to the blood inlet 2 of the membrane oxygenator 1 will be described.

The heat exchanger 15 accommodates a large number of heat exchange tubes (not shown) inside the housing, and blood flows into the heat exchanger 15 through the blood inlet 16 provided at the bottom of the housing, Flows through a blood chamber formed by an inner wall of the heat exchange tube, an outer surface of the heat exchange tube and a partition wall (not shown) that fixes the heat exchange tube to the housing in a fluid-tight manner. At that time, a heat exchange medium (for example, hot water or cold water) is caused to flow inside the heat exchange tube to heat or cool the blood as necessary.

As the heat exchanger 15, it is preferable to use one that allows blood to flow to the outside of such a heat exchange tube. In such a heat exchanger, since the pressure loss of blood flowing inside the heat exchanger is small, the velocity of the blood flow perfused by the heat exchanger 15 only by the difference between the human body and the heat exchanger is reduced significantly. Without
It can be sent to the membrane oxygenator 1 attached to the blood outlet of the heat exchanger 15.

Therefore, it becomes more reliable to perfuse the membrane oxygenator including the heat exchanger 15, the membrane oxygenator 1, and the blood reservoir 4 with blood only by the difference with the human body.

And, the blood inlet 16 of the heat exchanger 15 is provided at the lower portion thereof, and the blood outlet is provided at the upper portion thereof,
The air that has flown into the heat exchanger 15 together with the blood flows out from the blood outlet together with the blood flow, so it is less likely to be stored inside the heat exchanger 15, and thus the stored air and the heat exchange pipe body will remain for a long time. They do not come into contact with each other and the heat exchange efficiency in blood circulation is not significantly reduced. Similarly, in the membrane oxygenator 1, the blood inlet 2 is provided in the lower part of the housing, and the blood outlet 3 is provided in the upper part of the housing. Since the air that has flowed in together with the blood flows out from the blood outlet 3 together with the blood flow, it is less likely to be stored inside the membrane oxygenator 1, so that the stored air may contact the hollow fiber membrane 9 for a long time. In addition, there is little decrease in gas exchange efficiency during blood circulation.

In the membrane oxygenator of the present invention, since the membrane oxygenator 1 is attached after the heat exchanger 15, the blood before flowing into the membrane oxygenator 1, particularly when heating the blood. Is heated, the blood has a minimum water solubility in blood when flowing into the membrane oxygenator. Therefore, since blood flows into the membrane oxygenator 1 in a state of low solubility, while flowing through the membrane oxygenator 1,
The gas dissolved in blood rarely bubbles.
If it is assumed that the heat exchanger 15 is attached after the membrane oxygenator 1 to heat the blood, oxygen addition and carbon dioxide removal are performed in the membrane oxygenator 1 and water in the blood is changed. Blood with some dissolved gas flows into the heat exchanger. When the blood is heated, the solubility of the gas in the blood decreases, and the dissolved gas becomes fine bubbles and appears in the blood. Such fine bubbles may not be completely removed by the defoaming member provided in the blood storage tank. However, in the membrane oxygenator of the present invention, since the membrane oxygenator 1 is attached after the heat exchanger 15, there is no such problem and it is safer.

Further, the air flowing out from the membrane oxygenator 1 together with the blood flow is defoamed by the defoaming member 7 provided in the blood reservoir 4 and removed from the blood, so that the air is reliably removed from the blood. Therefore, the blood from which air has been removed is stored in the blood storage unit 6 of the blood storage tank 4, so that the blood mixed with air rarely flows out from the blood storage tank 4.

Further, the blood flowing out from the blood outlet 3 of the membrane oxygenator 1 and flowing into the blood reservoir 4 is defoamed by passing through the defoaming member 7, and due to the pressure loss of the defoaming member 7. Since the blood flow flowing out of the defoaming member 7 gently flows down from below to the blood storage portion 6 of the blood storage tank 4, it is less likely to drip on the blood surface stored in the blood storage portion 6, and bubbles are generated by the dropping. Can be prevented.

Further, the heat exchanger 15 is provided with a discharge line 19 for discharging blood to the vicinity of the blood discharge port 8 of the blood reservoir 4 without passing through the membrane oxygenator 1. Further, the heat exchanger 15 and the blood storage tank 4 are provided with temperature measurement probe insertion ports 17 and 18.

Then, in order to effectively perform the defoaming by the defoaming member 7 provided in the blood storage tank 4, it is preferable that the fineness of the foam of the defoaming member 7 is a certain degree or more.

If the eyes are too large relative to the size of the bubbles, the cells of the foam and the bubbles are not sufficiently contacted with each other, and small bubbles may flow out. However, conversely, if the eyes are too fine, the pressure loss in the foam increases, and blood accumulates on the blood inflow side of the foam, making it impossible to ensure the required flow rate. Further, at this time, if the foam is not wet with blood, a portion other than the flow path of the normal blood on the outflow side of the foam (a little above the portion where the bottom surface of the defoaming member is in contact). part)
The blood spouts out vigorously, and at that time, there is a risk that the blood will foam and the air bubbles will be mixed.

Therefore, the defoaming member 7 is a foam and has a small number of meshes of foam 7a and a small number of meshes of foam 7b.
It is preferable that two foams are closely adhered to each other, and two foams are further formed into a foam 7 having a large mesh number.
a is the blood inlet 12 side and foam 7 with a small mesh number
It is preferable to arrange in parallel so that b is on the side of the blood storage unit 6.
By using two foams with different mesh numbers and arranging them in parallel so that the mesh number becomes smaller in the blood flow direction, sufficient defoaming ability can be achieved without increasing the pressure loss. To have.

The number of meshes referred to here is the number of meshes between 25.4 mm (1 inch), and is originally a scale showing the size of the sieve mesh.

The thickness of the defoaming member and the number of meshes are relatively determined by the width of the flow channel and the maximum flow rate. here,
When the width of the flow path is 100 to 200 mm and the maximum flow rate is 6 / min, the thickness of the defoaming member 7 is 3 to 60 mm, preferably 10 to
It is 50 mm. If it is 3 mm or less, it may not have sufficient defoaming ability, and if it is 60 mm or more, the pressure loss may be too large.

As a foam with a large number of meshes, the number of meshes is 8 ~
This is because the pressure loss may become excessively large at 20, preferably 10 to 15, and 20 mesh or more, and may not have sufficient defoaming ability at 8 mesh or less. More preferably, it is 13 mesh.

This is because the thickness is 3 to 50 mm, preferably 5 to 30 mm, and if it is 3 mm or less, it may not have sufficient defoaming ability, and if it is 50 mm or more, pressure loss may become too large.

As a foam with a small number of meshes, the number of meshes is 5
It is 12, preferably 6 to 10, because when it is 12 mesh or more, blood may be jetted from other than the normal blood flow path to cause bubbles, and when it is 5 mesh or less, it may not have sufficient defoaming ability. is there. It is preferably 8 mesh. The thickness is 3 to 80 mm, preferably 5 to 50 mm. If it is 3 mm or less, it may not have sufficient defoaming ability, and if it is 80 mm or more, the pressure loss may be too large.
The thickness ratio of the foam having a large mesh number to the foam having a small mesh number is 1:10 to 10: 1, preferably 1: 4 to 4: 1. Also, the sum of the number of meshes is 13 ~
32, preferably 15-25.

Although two kinds of foams are used here, a foam having a mesh number between them may be inserted between them to form a three-layer structure.

The foam used for the defoaming member 7 may be urethane foam, cellulose foam, nylon foam, or the like. Preferred is urethane foam.

Further, it is preferable to coat the defoaming member 7 with a defoaming agent. As the defoaming agent, oils can be generally used, and silicone oil can be particularly preferably used.

[Operation] The operation of the membrane oxygenator of the present invention will be described with reference to the embodiments shown in the drawings.

This membrane oxygenator is provided in an extracorporeal circulation circuit, and blood flowing from a blood inlet 16 provided in a lower part of a heat exchanger 15 is introduced into a blood inlet 2 provided in a lower part of a membrane oxygenator 1. It is heated or cooled during the process. Then, the blood flowing in from the blood inlet 2 provided in the lower part of the membrane oxygenator 1 removes carbon dioxide while passing through the blood chamber formed by the housing and the gas exchange membrane 9, and oxygen is added. To be done. At this time, the gas containing oxygen is caused to flow from the gas inflow portion 10 into the hollow fiber membrane which is the gas exchange membrane. The blood to which oxygen has been added and carbon dioxide has been removed flows out from the blood outlet 3 provided in the upper part of the membrane oxygenator 1, flows into the blood introducing unit 5 via the blood introducing port 12 of the blood reservoir 4. Then, the blood passes through the defoaming member 7, and the bubbles contained at this time come into contact with the cells of the foam of the defoaming member 7, grow and move above the blood reservoir and are removed, and the blood reservoir of the blood reservoir 4 is removed. It is stored in 6, discharged from the blood discharge port 8 and sent to blood.

[Advantages of the Invention] A membrane oxygenator of the present invention is a membrane oxygenator having a heat exchanger, a membrane oxygenator, and a blood reservoir, and the heat exchanger is a heat exchanger of a heat exchanger. It has a blood inlet provided in the lower part and a blood outlet provided in the upper part of the heat exchanger, and the membrane oxygenator comprises a housing and a gas exchange hollow fiber membrane housed in the axial direction of the housing. An aggregate, a partition wall that holds both ends of the aggregate of hollow fiber membranes in the housing in a liquid-tight manner, a gas inflow portion and a gas outflow portion that communicate with the internal space of the hollow fiber membrane, and an axial direction of the housing. It is provided at the bottom,
A blood chamber formed by the inner wall of the housing, the partition wall, and the outer wall of the hollow fiber membrane is communicated with each other, and a blood inlet port connected to the blood outlet port of the heat exchanger, and an axial upper portion of the housing. A blood inlet connected to the blood chamber, the blood reservoir is connected to the blood outlet of the membrane oxygenator, and a blood reservoir communicating with the blood inlet. Since, in particular,
Since the blood inlet of the heat exchanger is provided in the lower part thereof and the blood outlet is provided in the upper part thereof, the air flowing into the heat exchanger together with the blood flows out from the blood outlet together with the blood flow. In addition, since the blood is rarely stored inside the heat exchanger, and also in the membrane oxygenator, the blood inlet is provided in the lower part of the housing, and the blood outlet is provided in the upper part of the housing. The air that has flown into the type oxygenator together with blood flows out from the blood outlet together with the blood flow, and therefore is rarely stored inside the membrane type oxygenator.

Therefore, the stored air does not come into contact with the heat exchange tube or the hollow fiber membrane for a long time, and the heat exchange efficiency and the gas exchange efficiency during blood circulation are less likely to decrease. Further, in the membrane oxygenator of the present invention, since the membrane oxygenator is attached after the heat exchanger, when heating the blood, the blood is warmed before flowing into the membrane oxygenator. Therefore, when the blood flows into the membrane oxygenator, the water in the blood has the lowest gas solubility. Therefore, since blood flows into the membrane oxygenator in a state of low solubility, it is safe that gas dissolved in the blood is not bubbled while flowing through the membrane oxygenator.

Further, the blood reservoir is located between the blood inlet and the blood reservoir, and has a blood inflow portion that communicates with the blood inlet and the blood reservoir, and the blood inlet has a blood flow path of the blood inflow portion. If the defoaming member is provided so as to cross,
The air flowing out from the membrane oxygenator along with the blood flow is defoamed by the defoaming member provided in the blood reservoir and is removed from the blood, so that the air can be reliably removed from the blood, Since the blood from which air has been removed is stored in the blood reservoir of the blood reservoir, blood containing air is less likely to flow out from the blood reservoir, and further flows out from the blood outlet of the membrane oxygenator to the blood reservoir. The blood that has flowed in is defoamed by passing through the defoaming member, and due to the pressure loss of the defoaming member, the blood flow that flows out of the defoaming member flows down gently from below to the blood reservoir of the blood reservoir. As a result, it is less likely to drip on the surface of the blood stored in the blood reservoir, and the generation of bubbles due to the drip can be prevented.

[Brief description of drawings]

The drawing is a partially cutaway side view of the membrane oxygenator of one embodiment of the present invention. 1 ... Membrane oxygenator, 2 ... Blood inflow port 3 ... Blood outflow port, 4 ... Blood reservoir 5 ... Blood inflow part, 6 ... Blood storage part 7 ... Defoaming member, 8 ... Blood drainage Outlet 7a: Foam with a large number of meshes 7b: Foam with a small number of meshes 9: Hollow fiber membrane, 10: Gas inflow part 11: Gas outflow part, 12: Blood inlet 13: Lid , 15 ...... Heat exchanger 16 ...... Blood inlet, 20 ...... Communication part 21 ...... Locking part, 30 ...... Baffle plate

Claims (9)

[Claims] 1. A membrane oxygenator having a heat exchanger, a membrane oxygenator, and a blood reservoir, wherein the heat exchanger comprises a blood inlet provided at a lower portion of the heat exchanger, A blood outlet provided on the upper part of the exchanger, the membrane oxygenator is provided in a vertical direction, and an assembly of a housing and a hollow fiber membrane for gas exchange housed in an axial direction of the housing. A partition wall that holds both ends of the aggregate of hollow fiber membranes in the housing in a liquid-tight manner, a gas inflow portion and a gas outflow portion that communicate with the internal space of the hollow fiber membrane, and a lower portion in the axial direction of the housing. A blood inlet provided to communicate with a blood chamber formed by an inner wall of the housing, the partition wall and an outer wall of the hollow fiber membrane, and further connected to a blood outlet of the heat exchanger, and a shaft of the housing. Blood provided in the upper part of the direction to communicate with the blood chamber. And an outlet, the blood reservoir includes a blood inlet connected to the blood outlet of the membrane oxygenator,
A membrane oxygenator, comprising a blood reservoir communicating with the blood inlet and a blood outlet provided in a lower portion of the blood reservoir. 2. The heat exchanger has a large number of heat exchange pipes housed therein, blood further flows outside the heat exchange pipes, and heat exchanges inside the heat exchange pipes. The membranous oxygenator according to claim 1, wherein the medium for use flows. 3. The membrane oxygenator according to claim 1, wherein the blood reservoir is formed of a transparent member. 4. The blood reservoir is located between the blood inlet and the blood reservoir, and has a blood inflow portion communicating with the blood inlet and the blood reservoir. The membrane oxygenator according to any one of items 1 to 3. 5. The membrane oxygenator according to claim 4, wherein the blood inflow portion is provided with a defoaming member so as to cross a blood flow path of the blood inflow portion. 6. The membranous oxygenator according to claim 5, wherein the defoaming member is formed of urethane foam. 7. The membrane oxygenator according to claim 5, wherein the defoaming member is coated with an antifoaming agent. 8. The membrane oxygenator according to claim 7, wherein the defoaming agent is silicone. 9. The blood storage tank is provided above the blood storage tank,
The membrane oxygenator according to any one of claims 1 to 8, further comprising a communication portion that communicates the inside and the outside of the blood reservoir.