JPH049544B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hollow fiber membrane type fluid treatment device such as an artificial lung or an artificial kidney.

[Prior Art] Generally, when performing thoracic surgery, etc., an extracorporeal blood circulation circuit is constructed using an artificial lung, and gas exchange of carbon dioxide and oxygen with the blood is performed by the artificial lung. Furthermore, when renal function declines, a dialysis circuit is constructed using an artificial kidney, and blood is filtered by the artificial kidney.

Conventionally, the above-mentioned artificial lungs, artificial kidneys, etc. have been constructed using a method in which the inside of the membrane is a flow path for a first fluid (e.g., gas containing oxygen), the outside is a flow path for a second fluid (e.g., blood), and the membrane is used as a flow path for a second fluid (e.g., blood). a hollow fiber membrane bundle formed by bundling a plurality of hollow fiber membranes for processing fluid; a cylindrical housing housing the hollow fiber membrane bundle; a first fluid inlet and a first fluid outlet, each provided with a first fluid inlet and a first fluid outlet;
A hollow fiber membrane type fluid treatment device comprising a second fluid inlet and a second fluid outlet provided on the upstream and downstream sides of the second fluid flow path has been proposed.

[Problems to be Solved by the Invention] By the way, in the hollow fiber membrane type fluid treatment device described above, it is possible to reduce the pressure loss within the housing of the second fluid flowing outside the hollow fiber membrane bundle;
It is desirable to equalize the flow state of the second fluid within the housing over the entire area of the housing. The reason for this is as follows.

If the pressure loss of the second fluid within the housing is large, the supply pressure of the second fluid for feeding the second fluid into the housing becomes excessive.
This may cause damage to the joints of the device and damage to components of the second fluid (for example, blood cells).
In addition, head perfusion, which supplies the second fluid only through the head difference between the patient and the device, cannot be applied, and it is necessary to install a pump upstream of the device, so a pulsatile flow pump is installed downstream of the device. Therefore, stable blood return to the living body cannot be ensured, and there is a risk that air bubbles may be drawn into the second fluid within the device.

If the flow condition (flow rate, flow velocity) of the second fluid in the housing is non-uniform around the hollow fiber membrane bundle in its axial direction, the second fluid flows through the hollow fiber membranes to the first fluid. The chances of contact with the fluid become non-uniform at various locations within the housing, resulting in a decrease in fluid processing performance such as oxygen addition.

The present invention reduces the pressure loss within the housing of the second fluid flowing outside the hollow fiber membrane bundle, and equalizes the flow condition of the second fluid within the housing over the entire area of the housing. The purpose is to

[Means for Solving the Problems] The hollow fiber membrane type fluid treatment device of the present invention uses the inside of the membrane as a first fluid flow path, the outside as a second fluid flow path, and A hollow fiber membrane bundle formed by bundling a plurality of hollow fiber membranes for processing fluid, a cylindrical housing housing the hollow fiber membrane bundle, and a hollow fiber membrane bundle on the upstream and downstream sides of the first fluid flow path, respectively. A first fluid inlet and a first fluid outlet provided, and a second fluid inlet and a second fluid outlet provided on the upstream and downstream sides of the second fluid flow path, respectively. A plurality of second fluid inlets are provided on the wall of the housing, and each of the plurality of second fluid inlets provided on the wall of the housing is on the same straight line in the axial direction of the housing. The housing is provided in a position that is not in the same position as the housing and in the same plane perpendicular to the axial direction of the housing.

[Function] According to the present invention, since the second fluid inlet is provided at each of a plurality of positions on the wall surface of the housing, if the processing flow rate of the second fluid is the same, each fluid inlet will share the load. The inflow flow rate can be reduced. Therefore, if the area of the second fluid flow path formed around the hollow fiber membrane bundle in the housing is the same, the above-mentioned fluid of the second fluid flowing into the fluid flow path from each fluid inlet The flow rate in the channel also decreases. Since the pressure loss within the housing is approximately proportional to the flow rate in the fluid flow path, the lower the flow rate, the lower the pressure loss can be.

As described above, since the pressure loss of the second fluid within the housing can be reduced, the supply pressure of the second fluid for feeding the second fluid into the housing can be reduced, and the device It is possible to eliminate the risk of damage to the joints, etc. of the fluid, and damage to components of the second fluid (for example, blood cells). In addition, head perfusion can be applied in which the second fluid is supplied only through the head difference between the patient and the device, eliminating the need to install a pump upstream of the device, and allowing a pulsatile flow pump to be installed downstream of the device. This makes it possible to ensure stable blood return to the living body, and also to eliminate the risk of air bubbles being drawn into the second fluid device.

Further, according to the present invention, the inflow flow rate shared by each of the plurality of second fluid inlets can be reduced as described above, so that a large amount of the second fluid can be concentrated from a single fluid inlet. Compared to the case where the second fluid flows into the hollow fiber membrane bundle, the amount of the second fluid flowing into the hollow fiber membrane bundle is reduced, and the tendency of the second fluid to flow unevenly within the housing can be suppressed. Therefore, the state of the flow of the second fluid within the housing can be made uniform over the entire area of the housing.

As described above, the flow state (flow rate, flow velocity) of the second fluid within the housing can be made uniform around the hollow fiber membrane bundle in its axial direction, so that the second fluid flows through the hollow fiber membrane. The chances of contact with the first fluid through the housing become uniform throughout the housing, improving fluid processing performance such as oxygen addition.

Further, according to the present invention, each of the plurality of second fluid inlets is provided at a position that is not on the same straight line in the axial direction of the housing, so that the fluid flows into the housing from each fluid inlet and becomes hollow. The flows of the second fluid surrounding the thread bundle are offset from each other about the axis of the housing. As a result, the overlap of the second fluid flows supplied into the housing from each fluid inlet in the axial direction of the housing is reduced, the aforementioned pressure loss reduction effect can be ensured, and the second The distribution of the fluid around the hollow fiber membrane bundle can be further promoted, and the above-mentioned flow uniformity effect can be ensured.

Further, according to the present invention, since each of the plurality of second fluid inlets is provided in the same plane perpendicular to the axial direction of the housing, the second fluid inlet formed around the hollow fiber membrane bundle is The annular flow path for fluid is divided in the circumferential direction at each of the plurality of fluid inlets. Therefore, the length of the flow path per fluid inlet is shortened, and by reducing the flow path resistance to the fluid, the aforementioned pressure loss reduction effect can be ensured, and the distance between the near and far side of each fluid inlet can be ensured. The difference in flow velocity of the fluid is reduced, and the above-mentioned flow uniformity effect can be ensured.

[Example] Fig. 1 is a half-sectional view showing a hollow fiber membrane oxygenator according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line of Fig. 1, and Fig. 3 is a cross-sectional view of Fig. 1. FIG. 4 is a cross-sectional view showing an extracorporeal blood circulation apparatus equipped with an artificial lung, and FIG. 4 is a perspective view of FIG. 3.

As shown in FIGS. 3 and 4, the extracorporeal blood circulation device 10 includes an artificial lung 11, a heat exchanger 12, and a blood storage tank 13.
It is an integrated structure that integrates the three parties. The heat exchanger 12 is installed upstream of the oxygenator 11, and is connected to the oxygenator 11 via two connecting pipes 12A and 12B. The blood storage tank 13 is installed downstream of the oxygenator 11, and has two connecting pipes 13A and 13B.
It is connected to the artificial lung 11 via.

The artificial lung 11 is constructed as shown in FIG. That is, a hollow fiber membrane bundle 17 formed by bundling a plurality of hollow fiber membranes 16 is housed in the internal space of the cylindrical housing 15 . Both ends of the hollow fiber membrane 16 are connected to partition walls 18 and 1 with both ends opened.
The housing 15 is fluid-tightly held via the housing 9. Headers 2 are provided at both ends of the housing 15.
0 and 21 are joined. The inner surface of the header 20 and the partition wall 18 define a gas inflow chamber 22 that communicates with the internal space (first fluid flow path) of the hollow fiber membrane 16. ) gas inlet port 23 (first fluid inlet)
is formed. Inner surface of header 21 and partition wall 1
9 defines a gas outflow chamber 24 communicating with the internal space of the hollow fiber membrane 16, and the header 21 is formed with a gas outflow port 25 (first fluid outflow port) for gas containing oxygen. There is. That is, artificial lung 1
1, gases such as oxygen and air supplied from the gas inflow port 23 are allowed to flow into the hollow fiber membrane 16. Note that the header 21 may not be particularly provided, and the gas flowing out from the hollow fiber membrane 16 may be directly released into the atmosphere without forming the gas outflow chamber 24 and the gas outflow port 25.

Furthermore, the partition walls 18 and 19, the inner surface of the housing 15, and the outer surface of the hollow fiber membrane 16 define a blood chamber 26 (second fluid flow path), and both ends of the housing 15 are connected to the blood chamber 26, respectively. , two blood inflow ports 27A, 27B (second fluid inlet) connected to the connecting conduits 12A, 12B, and two blood outflow ports 28A, 28B (second fluid inlet) connected to the connecting conduits 13A, 13B. A second fluid outlet) is formed. That is, in the case of the artificial lung 11,
Blood (second fluid) is allowed to flow around the hollow fiber membrane 16 in the blood chamber 26 in a turbulent state.

Here, the inner surface of the portion of the housing 15 where the blood inflow ports 27A, 27B are provided is as follows:
An annular blood flow path as shown in FIG. 2 is provided between the inner surface of the housing 15 extending outward from the inner surface of the axially intermediate portion and the outer circumference of the hollow fiber membrane bundle 17 of the hollow fiber membrane 16. 29, so that blood can be smoothly distributed to each hollow fiber membrane 16 from the entire periphery of the hollow fiber membrane bundle 17 facing the blood flow path 29. Further, the expanded inner surface of the housing 15 is connected to the hollow fiber membrane bundle 1.
7, the blood inflow ports 27A, 2 are eccentrically arranged in a direction including the blood inflow ports 27A, 27B.
The flow path area of the blood flow path 29 facing 7B is larger. That is, the flow area of the blood flow path 29 is gradually decreased as it moves away from the blood inflow ports 27A, 27B, and the amount of blood distributed from the blood flow path 29 is made uniform in the circumferential direction of the hollow fiber membrane bundle 17.
The flow rate of blood in the axial direction of the housing 15 within the blood chamber 26 can be made uniform in the circumferential direction of the hollow fiber membrane bundle 17.

Further, each of the two blood inflow ports 27A and 27B provided in the housing 15 is opened so that the streamlines thereof are not located on the normal line of the outer peripheral surface of the hollow fiber membrane bundle 17. (See Figure 2). This allows each blood inflow port 2
The streamlines of blood flowing into the blood chamber 26 from 7A and 27B are prevented from colliding perpendicularly with the outer peripheral surface of the hollow fiber membrane bundle 17, and as a result, the blood is selectively concentrated on the hollow fiber membrane bundle 17. This allows the blood to flow uniformly in the circumferential direction of the blood flow path 29 on the outer surface of the hollow fiber membrane bundle 17 without flowing.

In addition, the blood outflow port 2 of the housing 15
The inner surface of the portion where 8A and 28B are provided is an inner surface that expands outward from the inner surface of the intermediate portion of the housing 15, and is the inner surface of the hollow fiber membrane bundle 17 of the hollow fiber membrane 16.
An annular blood flow path 30 is formed between the outer periphery of the hollow fiber membrane 16 and the blood around each hollow fiber membrane 16 is smoothly transferred from the entire periphery of the hollow fiber membrane bundle 17 facing the blood flow path 30 to the blood outflow port. It is possible to introduce it towards 28A and 28B. Further, the expanded inner surface of the housing 15 is eccentric in a direction including the blood outflow ports 28A and 28B with respect to the hollow fiber membrane bundle 17 in the same manner as on the blood inflow ports 27A and 27B side in FIG. blood outflow port 28A, 2
The flow path area of the blood flow path 30 facing 8B is made larger. That is, by gradually increasing the flow path area of the blood flow path 30 toward the blood outflow ports 28A and 28B, the volume of the housing 15 is not made excessive and the extracorporeal blood circulation amount (priming volume) from the living body is not made excessive. Under conditions that ensure the safety of the living body, the amount of blood introduced into the blood flow path 30 is made uniform in the circumferential direction of the hollow fiber membrane bundle 17, and the flow rate of blood in the axial direction of the housing 15 in the blood chamber 26 is made uniform in the circumferential direction of the hollow fiber membrane bundle 17. It is possible to make the thread membrane bundle 17 uniform in the circumferential direction.

Furthermore, the housing 15 has a tapered shape in which the inner diameter at the center in the axial direction is the minimum, and the inner diameter gradually increases from the center to both ends, so that the outer diameter of the hollow fiber membrane bundle 17 extends along the inner wall of the housing 15. It is narrowed down to its smallest size at the center in the axial direction. That is, the artificial lung 11
By squeezing the hollow fiber membrane bundle 17 applied by the housing 15, the blood flow in the cross section of the hollow fiber membrane bundle 17 is made uniform, and the blood flow velocity in the axial direction of the hollow fiber membrane bundle 17 is changed. This promotes the generation of turbulent flow and makes it possible to improve the gas exchange rate.

Here, a microporous membrane is used as the hollow fiber membrane 16. That is, the hollow fiber membrane 16
is made of a porous polyolefin resin such as polypropylene or polyethylene, with polypropylene being particularly preferred. This hollow fiber membrane 16 has a large number of pores that communicate between the inside and outside of the wall. The inner diameter of the pore is approximately 100-1000μ,
The wall thickness is about 10-50μ, the average pore diameter is about 200-2000Å, and the porosity is 20-80%. When using the hollow fiber membrane 16 made of this microporous membrane, gas movement is performed as a volumetric flow, so the membrane resistance in gas movement is reduced, making it possible to obtain high gas exchange performance. In addition, hollow fiber membrane 1
6 does not necessarily use a microporous membrane, but may use a silicone membrane or the like in which gas movement is performed by dissolution and diffusion.

The heat exchanger 12 houses a large number of heat exchange tubes 32 in a cylindrical housing 31. One end of each tube 32 is connected to a hot water or cold water supply port 33, and the other end of each tube 32 is connected to a water supply port 33 for hot water or cold water. A drainage port 34 is communicated with the drain port 34. Further, the housing 31 is provided with a blood supply port 35. As a result, the blood supplied from the blood supply port 35 passes around the tube body 32 and is heated or cooled to a predetermined temperature, and then flows into the oxygenator 11 via the aforementioned connection pipes 12A and 12B. It flows into the blood flow path 29 from ports 27A and 27B.

The blood storage tank 13 is connected to the aforementioned connection pipes 13A and 13B.
It is provided with blood inflow ports 36A and 36B connected to each other to store blood that has been oxygenated by the oxygenator 11, and a blood outflow port 37 that sends out the stored blood to the living body. Note that 38 is a urethane antifoaming agent, and 39A and 39B are chemical solution mixing ports.

Next, the operation of the above embodiment will be explained.

An artificial lung is used, for example, in open heart surgery, and is installed in the middle of a blood circulation circuit. Note that blood is usually taken out at a flow rate of 4/min.

In the extracorporeal blood circulation apparatus 10, blood supplied from the blood supply port 35 to the heat exchanger 12 passes around the heat exchange tube body 32, is heated or cooled to a predetermined temperature, and then passes through the connection pipe 12A, The blood is sent to the blood inflow ports 26A and 26B of the oxygenator 11 via the oxygen pump 12B. Blood inflow port 27 of artificial lung 11
The blood sent to A and 27B flows through the blood flow path 29
After moving around the hollow fiber membrane bundle 17 in the blood chamber 26, undergoing gas exchange, and reaching the blood flow path 30,
Connecting conduit 13 from blood outflow ports 28A and 28B
Blood inflow port 3 of blood storage tank 13 via A and 13B
It is sent to 7A and 37B. Blood that has been oxygenated through gas exchange in the artificial lung 11 is stored in the blood storage tank 13, and is sent to the living body by the action of a pump connected to the blood outflow port 37.

According to the above embodiment, since the blood inflow ports 27A and 27B are provided at two positions on the wall surface of the housing 15, if the blood processing flow rate is the same, each blood inflow port 27A and 27B is provided at two positions on the wall surface of the housing 15. The amount of inflow flow to be shared can be reduced. Therefore, the housing 15
If the area of the fluid flow path 29 formed around the hollow fiber membrane bundle 17 in is the same, the flow rate in the fluid flow path 29 of the blood flowing into the fluid flow path 29 from each blood inflow port 27A, 27B is also small. Become. Since the pressure loss of the housing 15 is approximately proportional to the flow rate in the blood flow path 29, the lower the flow rate, the lower the pressure loss can be.

As described above, since the pressure loss of blood in the housing 15 can be reduced, the blood supply pressure for feeding blood into the housing 15 can be reduced, which can prevent damage to the joints of the device 10, etc. It is possible to eliminate the possibility of damage to components (for example, blood cells). In addition, head perfusion can be applied in which blood is supplied only through the head difference between the patient and the device 10, eliminating the need to install a pump upstream of the device 10.
A pulsatile flow pump can be installed downstream of the device 10 to ensure stable blood return to the living body.
It also eliminates the risk of air bubbles being trapped inside.

Further, according to the present invention, since the number of blood inflow channels shared by each of the two blood inflow ports 27A and 27B can be reduced as described above, a large amount of blood can be intensively injected from a single blood inflow port. Compared to the case where the blood flows into the hollow fiber membrane bundle 17, the amount of blood that enters the hollow fiber membrane bundle 17 is reduced, and the tendency of blood to drift inside the housing 15 can be suppressed. Therefore, the flow state of blood within the housing can be made uniform throughout the housing 15.

As described above, the flow state (flow rate, flow velocity) of blood inside the housing 15 is controlled by the hollow fiber membrane bundle 17.
Since the blood can be made uniform around the housing 15 and in its axial direction, the chances of the blood coming into contact with the oxygen-containing gas through the hollow fiber membrane 16 are uniform throughout the interior of the housing 15, and oxygenation can be improved.

In the above embodiment, since the two blood inflow ports 27A and 27B are provided at positions that are not on the same straight line in the axial direction of the housing 15, the housing 1
Flows of blood flowing into the inside of the housing 15 and surrounding the hollow fiber membrane bundle 17 are shifted from each other about the axis of the housing 15. This reduces the overlapping of the blood flows supplied into the housing 15 from the respective ports 27A, 27B in the axial direction of the housing 15, ensuring the aforementioned pressure loss reduction effect, and The distribution around the hollow fiber membrane bundle 17 can be further promoted, and the above-mentioned flow uniformity effect can be ensured.

Further, in the above embodiment, since the two blood inflow ports 27A and 27B are provided in the same plane perpendicular to the axial direction of the housing 15, the annular blood flow path 29 formed around the hollow fiber membrane bundle 17 are used separately for each of the two ports 27A and 27B in the circumferential direction. Therefore, each port 27A, 27B
The flow path length of each blood flow path 29 is shortened, and the above-mentioned pressure loss reduction effect can be ensured by reducing the flow path resistance to the blood. By the way, the difference in blood flow velocity is reduced, and the above-mentioned flow uniformity effect can be ensured.

[Effects of the Invention] According to the present invention, the pressure loss within the housing of the second fluid flowing outside the hollow fiber membrane bundle is reduced, and the flow state of the second fluid within the housing is reduced. It can be made uniform over the entire area of the housing.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view showing a hollow fiber membrane oxygenator according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing the extracorporeal blood circulation device provided, and FIG. 4 is a perspective view of FIG. 3. DESCRIPTION OF SYMBOLS 11... Oxygenator, 15... Housing, 16... Hollow fiber membrane, 17... Hollow fiber membrane bundle, 23... Gas inflow port (first fluid inlet), 25... Gas outflow port (first outflow/inflow port), 26... Blood chamber (second fluid flow path), 27A, 27B... Blood inflow port (second fluid inlet), 28A, 28B... Blood outflow port (second fluid outlet).

Claims (1)

[Claims] 1. A hollow fiber membrane bundle formed by bundling a plurality of hollow fiber membranes in which the inside of the membrane serves as a flow path for a first fluid, the outside serves as a flow path for a second fluid, and fluid is processed through the membrane; a cylindrical housing housing the hollow fiber membrane bundle; a first fluid inlet and a first fluid outlet provided on the upstream and downstream sides of the first fluid flow path; and the second fluid flow path. a second fluid inlet and a second fluid outlet provided on the upstream and downstream sides of the fluid flow path of the housing, a plurality of second fluid inlets are provided on the wall surface of the housing, and a plurality of second fluid inlets are provided on the wall surface of the housing; The plurality of second fluid inlets provided on the wall surface of the housing are provided at positions that are not on the same straight line in the axial direction of the housing and in the same plane perpendicular to the axial direction of the housing. Characteristic hollow fiber membrane fluid treatment device.