JPH03158166A - Hollow fiber membrane type fluid treating device - Google Patents

Abstract

PURPOSE:To cause the uniform passage of flowing-in fluid between hollow fiber membranes and to perform the effective use of the whole of a membrane wall by a method wherein the optimum condition of the filling rate of the hollow fiber membrane in a housing is provided. CONSTITUTION:A porous hollow fiber membrane 6 is disposed substantially in parallel along the longitudinal direction of a housing 2. The filling rate in a housing of a hollow fiber membrane is set to a value within a range of 45-65%. Thus, flowing-in fluid uniformly passes a gap between the hollow fiber membranes 6 and 6. This constitution increases the efficient of contact between the membrane surface of the hollow fiber membrane and fluid, ensures an enough effective membrane area, and improves fluid treating ability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hollow fiber membrane type fluid treatment device in which fluid treatment such as gas exchange is performed through the membrane wall of a porous hollow fiber membrane.

[Prior art] In recent years, in heart surgery, etc., the patient's blood is guided outside the body.
In order to add oxygen and remove carbon dioxide gas, a hollow fiber membrane oxygenator is used to constitute an extracorporeal circulation circuit.

This hollow fiber membrane oxygenator generally has a plurality of hollow fiber membranes bundled together and housed in a housing, and blood is circulated as a fluid to be treated either inside or outside of these hollow fiber membranes. Oxygen-containing gas is blown to the other side as a processing fluid, and gas-liquid contact is carried out through the membrane wall of the hollow fiber membrane, thereby performing desired gas exchange.

Among such hollow fiber membrane oxygenators, blood is circulated inside the hollow fiber membrane, and oxygen-containing gas is blown outside the membrane.
As for the so-called internal perfusion type,
One example is the one published in Publication No. 8947.

[Problems to be Solved by the Invention] Incidentally, in the hollow fiber membrane oxygenator disclosed in the above-mentioned publication, conventionally, the gap between the hollow fiber membranes is narrow in the housing, and the gap between the hollow fiber membranes is narrow along the axial direction. The hollow fiber membrane bundle was stored in a bundle in a state where it could not be actively changed, and the hollow fiber membrane bundle had a constriction part due to the restraining part. In this way, the filling rate of the hollow fiber membrane is high in the constricted area and low in other areas, so when oxygen-containing gas is blown, the contact between this gas and the hollow fiber membrane surface is uneven, making the entire area less effective. I couldn't say it was being used.

The present invention has been made in view of such problems, and includes:
The purpose is to provide optimal conditions for the filling rate of the hollow fiber membranes in the housing, so that the inflowing fluid can pass evenly between the hollow fiber membranes and the entire membrane wall can be used effectively. Oxygen-containing gas is blown outside the
When blood flows inside the hollow fiber membrane, it is possible to improve the flow of oxygen-containing gas, ensure sufficient effective membrane area for contact between blood and oxygen-containing gas, and improve gas exchange performance. Provided is a hollow fiber membrane type fluid treatment device that can smooth the flow of fluid in gaps, proactively and sufficiently secure an effective membrane area where fluid can come into contact through membrane walls, and improve fluid processing performance. It's about doing.

[Means for Solving the Problems 1] In order to solve the above-mentioned conventional problems, the present invention has a housing, and a hollow fiber bundle consisting of a plurality of porous hollow fiber membranes for gas exchange is housed in the housing. and a hollow fiber membrane type fluid treatment device that performs fluid treatment of the fluid to be treated between the fluid to be treated on either the inside or outside of the porous hollow fiber membrane and the other fluid to be treated via the membrane wall of the porous hollow fiber membrane. The porous hollow fiber membrane is arranged substantially parallel to the longitudinal direction of the housing, and the filling rate of the hollow fiber membrane in the housing is set in a range of 45 to 65%. It is something to do.

Further, in the hollow fiber membrane type fluid treatment device according to the present invention,
The inner diameter of the porous hollow fiber membrane is 100 to 500 μm, and the wall thickness is 2
It is preferable to set the hollow fiber membrane to 7 to 80 μm and further crimp the crimp rate in the range of 0.1 to 0.7%.

[Function] In the hollow fiber membrane type fluid treatment device according to the present invention having the above configuration, the porous hollow fiber membranes are disposed substantially parallel to each other along the longitudinal direction of the housing, and the hollow fiber membranes are arranged substantially parallel to each other along the longitudinal direction of the housing. Since the filling rate in the housing is set in the range of 45 to 65%, the inflowing fluid passes evenly between the hollow fiber membranes, and the contact rate between the membrane surface of the hollow fiber membrane and the fluid is reduced. is high (and a sufficient effective membrane area can be secured, resulting in improved fluid processing capacity).

Furthermore, by setting the crimp ratio of the hollow fiber membranes in the range of 0.1 to 0.7%, it is possible to ensure uniform gaps between the hollow fiber membranes, which prevents the occurrence of so-called channeling. The fluid flow becomes smoother, a larger effective membrane area can be secured, and at the same time, turbulence can be generated in the fluid flow.

Therefore, in a hollow fiber membrane oxygenator in which oxygen-containing gas is blown as a processing fluid to the outside of the hollow fiber membrane, and blood is circulated as a fluid to be treated inside the hollow fiber membrane, the hollow fiber membrane between blood and oxygen-containing gas is The fluid to be treated or the fluid to be treated in the gap between the hollow fiber membranes can be uniformly contacted over the entire surface of the hollow fiber membrane, and a sufficient effective membrane area can be secured to obtain high gas exchange performance. The flow becomes smoother,
An effective membrane area with which fluid can come into contact via the membrane wall of the hollow fiber membrane is positively and sufficiently ensured, making it possible to improve fluid processing ability.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a hollow fiber membrane oxygenator according to an embodiment of the present invention. This artificial lung is of a so-called internal perfusion type, in which blood is circulated as a fluid to be treated inside the hollow fiber membrane 6, and oxygen-containing gas is blown as a fluid to be treated outside the hollow fiber membrane 6.

This hollow fiber membrane oxygenator 1 has a housing 2, which is integrally formed with a cylindrical main body 3 and an enlarged diameter part 4.5 with an annular projection formed at both ends thereof. has been done. Inside the housing 2, a plurality of, for example, io
, ooo~60,000 porous hollow fiber membranes 6 are bundled together as a hollow fiber bundle 13 along the longitudinal direction of the housing 2 and housed. Both ends of the hollow fiber membranes 6 are supported in a liquid-tight manner by partition walls 7 and 8 within the cover 4.5 with the openings of each hollow fiber membrane 6 not being closed. A gas chamber 9 is formed between the outer circumferential surface of the porous hollow fiber membrane 6 and the inner surface of the housing 2 by the partition walls 7 and 8 . The above installation is with cover 4.5, and one is with cover 4.
The cover 5 is provided with an oxygen-containing gas inlet 10 for supplying oxygen-containing gas, and the other attached cover 5 is provided with an oxygen-containing gas outlet 11 for discharging oxygen-containing gas.

Note that the partition walls 7 and 8 are made of a highly polar polymer botting material,
For example, it can be obtained by pouring polyurethane, silicone, niboxy resin, etc. onto the inner wall surface of the open end of the housing 2 using a centrifugal injection method and curing it.

The outer surface of one of the partition walls 7 is covered with a blood boat cover 15 having a substantially conical shape. This blood boat cover 15 is attached by attaching liquid to the cover 4 by mutually engaging an annular protrusion 15a formed on the inner circumferential surface thereof and an annular protrusion 4a formed on the outer circumferential surface of the cover 4. They are tightly fitted, and a blood boat basin 23 is formed therein. A blood outlet 26 is formed in the blood boat cover 15.

A heat exchanger 12 is connected to the other partition wall 8 . The heat exchanger 12 has a housing 13, and the housing 13 includes a cylindrical main body 13a and a fitting member 13b. A plurality of stainless steel vibrators 14 are disposed within the cylindrical main body 13a, and are supported in a liquid-tight manner via partition walls 17 and 18 with openings at both ends thereof not being closed. In addition, cold and hot water flow ports 19 and 20 are provided on the circumferential side of the cylindrical body 13a, and a cold water or hot water flow path is formed in the cylindrical body 13a. is adjusted to the desired temperature. The outer surface of the partition wall 18 located on the opposite side to the partition wall 8 is covered with a blood boat cover 16 similar to the blood boat cover 15 described above. In addition, 24 is a blood boat area, 2
5 is a blood introduction port. The fitting member 13-b is liquid-tightly fitted to the enlarged diameter portion 5 in the same way as the blood boat cover 15, and a blood storage space 27 is formed between the partition walls 17 and 5.

In such a configuration, in the hollow fiber membrane oxygenator of the embodiment, the filling rate d of the porous hollow fiber membranes 6 within the cylindrical body 3 of the housing 2 is set in the range of 45 to 65%. If it is less than 45%, the gaps between the porous hollow fiber membranes 6 will become larger on average, and the oxygen-containing gas will flow unevenly to the part where the gaps are larger. That is, because the oxygen-containing gas does not flow uniformly between the porous hollow fiber membranes 6, the membrane area that actually functions for gas exchange cannot be obtained, and the oxygen addition ability, carbon dioxide removal ability, etc. are reduced, making it difficult to put into practical use. I can't offer it. On the other hand, if it exceeds 65%, the gap between the porous hollow fiber membranes 6 becomes small, and the oxygen-containing gas does not enter the inside of the hollow fiber bundle 13, but flows relatively toward the surface of the hollow fiber bundle 13. Become. That is, the oxygen-containing gas flows through the porous hollow fiber membrane 6.
If the membrane does not flow uniformly between the membranes, a membrane area that actually functions for gas exchange cannot be obtained, and the oxygen addition ability, carbon dioxide removal ability, etc. are reduced, making it impossible to put it into practical use.

Note that, within the above range, the filling rate d is preferably 55 to 65%, more preferably 57 to 65%.

Further, the porous hollow fiber membrane 6 has an inner diameter of 100 to 50
0 μm, preferably 150-300 μm, wall thickness 27-300 μm
It is 80 μm. Further, this porous hollow fiber membrane 6 is provided with crimp in a crimp ratio of 0.1 to 0.7%.

When the crimp rate is in the range of 0.1 to 0.7%, the hollow fiber membrane 6
Enough space can be secured between the two. Preferably 0.3 to 0.
It is in the range of 5%. If the crimp ratio is less than 1%, the gaps between the porous hollow fiber membranes 6 will not be sufficiently secured, and if the crimp ratio exceeds 0.7%, there is a risk that the oxygenator will become larger than necessary, and eventually I also don't like it.

The porous hollow fiber membrane 6 can be manufactured by the following method. That is, a hollow fiber membrane made porous by being spun by a drawing method or a phase separation method is wound cross-wound around a suitable bobbin or the like to impart crimps, and then crimped under suitable conditions, e.g. About 24 hours at C.
It is obtained by fixing the crimp state by heat treatment. At this time, when applying crimps, heat setting is performed more than necessary, and the membrane structure changes, for example, in cases where the porosity decreases by 10% or more compared to the state before crimping. teeth,
The effect of crimp is not achieved. Conversely, heat fixation may not be performed sufficiently, and even though the desired crimp state is maintained during the assembly of the oxygenator, residual stress builds up in the hollow fiber membranes and causes the crimp to be lost. Even with things, you can't get that effect.

Furthermore, this porous hollow fiber membrane 6 has a porosity of 37% and an oxygen gas flux of 20,000 to 30.00.
0β/min-m” 0.5 atm, preferably 24.
600±2.600f27min-m” 0.5 at
m, even better effects can be expected.

As the material for the porous hollow fiber membrane 6, for example, polyolefins such as polypropylene and polyethylene, and hydrophobic synthetic resins such as polytetrafluoroethylene can be used. Polypropylene is particularly suitable because it has excellent physical properties and can be easily imparted with porosity.

In the hollow fiber membrane oxygenator of this embodiment, the housing 2 is formed into a cylindrical shape, so that the porous hollow fiber membranes 6 are disposed substantially parallel to the longitudinal direction of the housing 2, and the porous hollow The filling rate of the thread membrane 6 in the housing 2 is 45.
~65%, and further set the crimp rate to 0.1~0.
Since it is set in the range of 7%, when oxygen-containing gas flows in from the gas inlet IO, the contact rate with the membrane surface of the porous hollow fiber membrane 6 is high (and the contact rate between the porous hollow fiber membranes 6 is high). The gap becomes uniform along the longitudinal direction of the housing 2. Therefore, the oxygen-containing gas blown into the gas chamber 9 does not cause drift, and is distributed between the porous hollow fiber membranes 6 in the center of the hollow fiber bundle 13. The oxygen-containing gas flows smoothly even into the gaps.Also, this oxygen-containing gas flows from the blood port region 24 to the porous hollow fiber membrane 6.
Contact with the blood flowing inside the porous hollow fiber membrane 6 is made uniform over the entire surface of the porous hollow fiber membrane 6, and a sufficient loading membrane area is secured.
As a result, high gas exchange performance can be obtained.

FIG. 3 shows a porous hollow fiber membrane 6 as another embodiment of the present invention.
This is a so-called external perfusion type hollow fiber membrane oxygenator in which blood is circulated as a treatment fluid outside the porous hollow fiber membrane 6 and oxygen-containing gas is blown inside the porous hollow fiber membrane 6 as a treatment fluid.

The hollow fiber membrane type oxygenator 31 according to this embodiment is composed of a cylindrical housing 32 and oxygen-containing gas port covers 33 and 34 provided at the open end of the cylindrical housing 32.

Inside the housing 32, as in the previous embodiment, there is a partition wall 7.
A hollow fiber bundle 13 made of porous hollow fiber membranes 6 is supported through the fibers 8 . A blood chamber 35 is formed within the housing 32 by the corner wall 78 . On the other hand, oxygen-containing gas port regions 33a, 34a are formed within the oxygen-containing gas port cover 33,34. The housing 32 is provided with a blood inlet 36 for supplying blood and a blood outlet 37 for discharging blood. Further, an oxygen-containing gas inlet 38 and an oxygen-containing outlet 39 are formed in the oxygen-containing gas port covers 33 and 34, respectively.

In the hollow fiber membrane oxygenator of this embodiment, with the above configuration, the oxygen-containing gas blown into the inside of the porous hollow fiber membrane 6 from the oxygen-containing gas port region 33a is transferred to the inside of the porous hollow fiber membrane 6. When coming into contact with blood flowing through the gaps between the porous hollow fiber membranes 6 through the pores, it becomes difficult for the blood to remain in the gaps (therefore, it becomes difficult to be trapped by so-called air traps. This makes the gaps between the porous hollow fiber membranes 6 The porous hollow fiber membrane 6 between the blood and the oxygen-containing gas is created by the air-trapped oxygen-containing gas mass.
The inhibition of contact through the membrane wall is eliminated, and therefore a sufficient effective membrane area is ensured.

Other functions and effects are similar to those of the previous embodiment.

Next, the present inventor conducted the following experiment in order to confirm the effect of the artificial lung of the above example.

(Examples 1 to 4) First, a porous hollow fiber membrane was manufactured by the following method.

The average pore radius formed by micro phase separation extraction method is approximately 5
A porous hollow fiber membrane made of polypropylene having 0.00 micropores, an inner diameter of 180 to 220 μm, and a wall thickness of 50 μm is wound crosswise around a bobbin with a diameter of 95 mm, and heat treated in an oven at 60° C. for 24 hours. 0.3~0
．． A crimping range of 5% was applied.

Using the hollow fiber membrane 6 obtained in this way, the first
Oxygenators with the same configuration as the hollow fiber membrane oxygenator l according to Example 1 but with different filling rates of 57.8, 60.0°, 61.9, and 62.4 were created, and oxygen gas addition capacity and carbon dioxide Gas elimination ability was measured. The results are shown in Table 1.

(Examples 5 to 8. Comparative Examples 1 to 4) An artificial lung in which the filling rate of the porous hollow fiber membrane 6 crimped in the same manner as in Examples 1 to 4 was lower than that in Examples 1 to 4. Lungs (Examples 5 to 8) and artificial lungs (Comparative Examples 1 to 4) which were higher than those of Examples 1 to 4 were prepared, respectively, and their oxygen gas addition ability and carbon dioxide removal ability were measured. The results are shown in Table-2 and Table-3.

Table 1 Table 2 Table 3 The definitions and measurement methods of each term in this specification are as follows.

The filling rate of the area where the entire circumference of the hollow fiber bundle is restrained by the L1 housing is expressed as the ratio of the total cross-sectional area of the hollow fiber membranes to the cross-sectional area of the internal space of the housing, that is, Regarding the filling rate of the portion where the entire circumference of the hollow fiber bundle is not restrained by the housing, the cross-sectional area of the housing interior space is defined as the area surrounded by the outer circumferential envelope of the hollow fiber bundle.

Yu 1 Blood Engineering 1 Remove 10 hollow thread membranes arbitrarily and cut them into rounds with a length of about LOmm using a sharp razor.

Conprofile projector V-12 as a universal projector
) and measure its outer diameter d8 and inner diameter d2 with a digital counter CM-63).
The wall thickness t was calculated as t=dl dz, and the average value of the 10 pieces was taken as the average value.

=Take about 2 g of LJL standing hollow fiber membrane and cut into rounds of 5 mm or less with a sharp razor. The obtained sample was heated to 1000 kg/am using a mercury porosimeter (Carloerova Model 65A).
” to obtain the porosity from the total pore volume (pore volume of the hollow fiber per unit weight).

After sterilizing the oxygenator, measurements were performed on the porous hollow fiber membrane taken out from the oxygenator.

The sample length of the porous hollow fiber membrane taken out was 70n+
+++ Closed. The measurement method is JIS L 1074
The crimp rate measurement method in 6.11.2 was used as a reference.

Specifically, a tensile testing machine (Autograph, AGS-100A) manufactured by Takasugi Seisakusho was used as a testing machine, and the tensile speed thereof was set to 1 mm/win.

Then, a load of 1 g is applied to the porous hollow fiber membrane of the above sample length using this testing machine, and the load at that time is designated as a, and then the length when a load of Log is applied is designated as b, A cycle test was performed three times between 1 g and log loads in the strograph cycle test mode at the above-mentioned tensile speed, and the average value of the three times was taken as the multi-value of a and b. From the measured values of a and b, the shrinkage rate was obtained using the following calculation formula.

Crimping rate (%) = (b-a) /ax l 00, gas Effective length of gas porous hollow fiber membrane 6 is 100 to 1351 Tlr
11. ll! The area is set to 0.8 to 5.0 m'', and bovine blood (standard venous blood) is fed inside the porous hollow fiber membrane 6 in a single pass at a rate of 0.8 to 5.0 β/
Pure oxygen is supplied to the outside of the porous hollow fiber membrane 6 at a flow rate of 0.8 to 5 min. Flow at a flow rate of On/min, pH 1 partial pressure of carbon dioxide (PCO2
), oxygen gas partial pressure (PO2) is measured using a blood gas measuring device (Ra
Measured by dioraeter, BGAB type),
The partial pressure difference between the oxygenator inlet and the oxygenator outlet was calculated.

As a result of the above, this Example 1 has a filling rate in the range of 45 to 65%.
~4 The oxygen-containing oxygen-containing oxygen-containing gas is a porous hollow fiber membrane 6.
It has been revealed that the porous hollow fiber membrane 6 has an excellent gas exchange ability as a result of the porous hollow fiber membrane 6 being used effectively.

Although the present invention has been described above with reference to Examples, the present invention is not limited to the above-mentioned Examples, and can be modified in various ways without changing the gist of the present invention. For example, in the above embodiments, an example in which the present invention is applied to a hollow fiber membrane type artificial lung has been described, but it goes without saying that the present invention can be applied to various other hollow fiber membrane type artificial kidneys and the like.

[Effects of the Invention] As explained above, in the hollow fiber membrane type fluid treatment device according to the present invention, without providing a constriction part in the housing,
The porous hollow fiber membranes were arranged substantially parallel to the longitudinal direction of the housing, and the filling rate of the porous hollow fiber membranes was set in the range of 45 to 65%, so that the inflowing fluid was porous. It passes evenly through the gaps between the hollow fiber membranes, increases the contact rate between the membrane surface of the porous hollow fiber membrane and the fluid, and ensures a sufficient effective membrane area, resulting in improved fluid treatment performance.

Therefore, in a hollow fiber membrane oxygenator in which oxygen-containing gas is blown as a processing fluid to the outside of a porous hollow fiber membrane, and blood is circulated as a fluid to be treated inside the membrane, the hollow fibers between blood and oxygen-containing gas are Contact through the membrane wall of the fiber membrane is made uniform over the entire surface of the hollow fiber membrane, a sufficient effective membrane area is secured, and high gas exchange performance can be obtained.

In addition, the porous hollow fiber membrane is crimped, and the crimping rate is 0.1 to 0.7.
Since it is set in the range of %, there is a
If the gaps are sufficiently large and actively change along the axial direction of the hollow fiber membrane, for example, when oxygen-containing gas is blown inside the porous hollow fiber membrane, the membrane is hydrophobic. Also, oxygen-containing gas does not accumulate in the gaps between the hollow fiber membranes, resulting in good blood circulation and further improving gas exchange ability. The flow becomes smooth, the effective membrane area where the fluid can come into contact through the membrane wall of the hollow fiber membrane is positively and sufficiently secured, and the fluid processing ability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional front view showing a hollow fiber membrane oxygenator according to a first embodiment of the present invention, and FIG. 2 is a half-sectional front view showing a hollow fiber membrane oxygenator according to a second embodiment of the present invention. It is a cross-sectional front view. 1.31...Hollow fiber membrane oxygenator 2.32...Housing 6...Hollow fiber membrane, 13...Hollow fiber bundle °C

Claims (3)

[Claims] (1) having a housing, in which a hollow fiber bundle consisting of a plurality of porous hollow fiber membranes for gas exchange is housed;
A hollow fiber membrane type fluid treatment device that performs fluid treatment of a fluid to be treated between either one of the fluid to be treated and the other fluid on the inside or outside of the porous hollow fiber membrane through the membrane wall, The hollow fiber membrane is characterized in that the porous hollow fiber membrane is arranged substantially parallel to the longitudinal direction of the housing, and the filling rate of the hollow fiber membrane in the housing is set in a range of 45 to 65%. Thread membrane type fluid treatment device. (2) The crimp rate of the porous hollow fiber membrane is 0.1 to 0.7%.
The hollow fiber membrane type fluid treatment device according to claim 1, wherein the hollow fiber membrane type fluid treatment device is set within the range of . (3) The inner diameter of the porous hollow fiber membrane is 100 to 500 μm.
Claim 2, wherein the wall thickness is set in the range of 27 to 80 μm.
The hollow fiber membrane type fluid treatment device described.