JPS622821B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION TECHNICAL FIELD The present invention relates to a hollow fiber oxygenator and a method for manufacturing the same, and more particularly to an improvement in a method for fixing both ends of a bundle of hollow fibers into an envelope. Prior Art It has been proposed to use a hydrophobic microporous membrane, such as a fiber made of porous polypropylene, as a hollow fiber built into a hollow fiber oxygenator. However, when using such a microporous membrane, if the pressure loss between the blood inlet and outlet is large, the internal pressure of the blood circuit on the side flowing into the oxygenator will increase, and if it is excessive, the latex rubber tube of the roller pump will swell greatly. Risk of rupture. Furthermore, it is also known that when the internal pressure of the circuit is high, red blood cells are often destroyed. Therefore, the total length of the internal space of this type of hollow-eye bar oxygenator must be determined by taking this pressure loss into account. The latex pump tube may bulge if the pressure exceeds 700 mmHg. In some cases, a pressure of 300 to 400 mmHg is generated near the arterial blood return catheter, so for safety, the pressure drop in the oxygenator must be less than 300 mmHg, preferably less than 200 mmHg. These conditions are: average pore diameter 200-2000Å, porosity 20
~85%, and applying it to the case of polypropylene fibers with an inner diameter of 200 μ, in a 3.3 m ² oxygenator, the effective length (distance of contact between blood and oxygen gas) is approximately 14 cm with a bundle of 37,500 fibers. . In this case, if the number of hollow eye bars is increased, the length of the oxygenator can be shortened by that amount, but the thickness of the oxygenator increases, which does not lead to a reduction in the size and weight of the entire oxygenator. Therefore, the inventor of the present invention has determined that the pressure loss of blood flow can be suppressed within the above-mentioned constant conditions by improving the fixing parts at both ends of the hollow-eye fiber bundle fixed in the envelope of the hollow-eye oxygenator. We have found that it is possible to reduce the size and weight of the entire oxygenator. FIG. 1 shows a conventional method for fixing a bundle of hollow fibers into an oxygenator envelope. That is, a single oxygenator envelope 1 containing a hollow fiber bundle is fixed in a centrifugal device (not shown) with fixing plates 2 arranged at both ends thereof, and an oxygen-containing gas is passed through an inlet 3 and an outlet 3. A high-viscosity adhesive such as polyurethane (so-called potting material) is housed near both ends of the oxygenator envelope 1, and then the arrow line "b" rotates around the center "a" of the envelope 1.
The potting material is densely packed into both ends of the envelope 1 by using the centrifugal force at that time, and each hollow eye bar is fixed inside the envelope 1, and the inside of the hollow eye bar is The outer flow path is airtightly partitioned. According to such a method of filling potting material, a considerable curvature occurs on the inner surface (the surface facing the center of the envelope 1) of the filled potting material. but,
In the past, the formation of this curved surface was considered to be unavoidable. However, the present inventor believes that the curved surface formed by such a conventional potting material filling method causes a considerable loss of the effective membrane area of the hollow eye bar, leading to an increase in the amount of potting material filled, and reducing the size of the oxygenator. The present invention was developed by paying attention to the fact that it hinders the product's appearance and impairs the appearance of the product. Purpose of the Invention This invention makes the inner surfaces of the potten material filled at both ends of the envelope nearly flat, thereby increasing the effective membrane area of the hollow fiber and reducing the amount of potten material filled. It is an object of the present invention to provide a hollow fiber oxygenator and a method for manufacturing the same, which can reduce the number of artificial lungs as much as possible, reduce the size of the oxygenator, and improve the appearance. That is, the present invention includes a cylindrical envelope that accommodates a large number of hollow fibers in parallel along the axial direction, and a cylindrical envelope that accommodates a large number of hollow fibers in parallel in the axial direction, and a cylindrical envelope that is provided at both ends of the envelope with only both ends of the accommodated hollow fibers being opened. A blood inlet/outlet port provided at both ends of the cylindrical body is communicated with a potten portion to be fixedly held, a blood inlet/outlet port provided at both ends of the cylindrical body by communicating with openings at both ends of the hollow fiber, and a blood inlet/outlet port provided at both ends of the hollow fiber in communication with an outer space of the hollow fiber in the envelope. In a hollow fiber oxygenator comprising a pair of oxygen supply gas inlet/output ports provided in the enclosure, the inner facing surfaces of both of the potten portions are concave, and the curvature is equal to the distance between the two outer surfaces of the potten portions. is l, and the thickness of the center of one potten is t
In this case, the present invention provides a hollow fiber artificial lung characterized by being drawn by a circular arc having a radius of curvature of at least lt or more. This invention further shows that the hollow eye bars have an average pore diameter.
200~2000Å, porosity 20~85%, inner diameter 100~300μ
The present invention provides the above-mentioned hollow fiber oxygenator which is made of polypropylene fiber. The present invention further provides a method in which a large number of hollow fibers are arranged in parallel along the axial direction in a cylindrical envelope, a viscous potting material is filled in the vicinity of one closed end of the envelope to be potted; Fixing the envelope to the centrifugal device in a state in which the envelope is radially spaced from the rotation center of the centrifugal device, with the one end of the envelope being outside, and the other end of the envelope being spaced at or further away from the rotation center. Then, rotate the centrifugal device,
The centrifugal force at that time causes the potten material to be densely packed into one end of the envelope, and then, after the potten material is cured, the vicinity of the end of the hollow eye bar including the potten material is cut. The present invention provides a method for manufacturing a hollow eye bar type oxygenator, characterized in that the end of each hollow eye bar is opened in the direction of the blood inlet/outlet. The above-mentioned method for producing a hollow-eye oxygenator is characterized in that a plurality of the envelopes containing the potting material and the hollow eye bars are arranged in a centrifugal device symmetrically with respect to the rotation axis of the centrifugal device, and the potting operation is performed simultaneously. This is what we provide. DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described with reference to the embodiments shown in FIGS. 2 and 3. In the embodiment shown in FIG. 2, a method is shown in which hollow fibers are simultaneously potted into envelopes 11 and 12 of two hollow fiber oxygenator lungs. That is, the envelopes 11 and 12 are connected to a centrifugal device (not shown).
The fixed plates 13, 14, 15 are arranged symmetrically around the rotation center "a", and the
an envelope 11 disposed between and outside these;
Fix 12. Each of these envelopes 11 and 12 contains an appropriate number of hollow fibers, for example, tens of thousands of hollow fibers (for example, an average pore diameter of 200 to 2000 Å, a porosity of 20
~85%, polypropylene fiber with an inner diameter of 100~300μ) are built in parallel along the axial direction of the envelopes 11, 12, and the outer ends 16, 17 of the envelopes 11, 12 (for example, by caps, etc. ) is filled with a potting material such as a polyurethane resin adhesive via nearby oxygen-containing gas introduction holes (or outlet holes) 18 and 19. In this state, rotate the envelopes 11 and 12 at the center of rotation "a".
When the potten material is rotated as shown by the arrow "b" around A curved surface that is the same as a circular arc drawn with a radius "c" corresponding to the distance from the center of rotation "a" to the potting material is formed on the surface opposite to "a". In this case, as shown in FIG. If it is made extremely thin and the value is close to zero, it will be almost l-t.
). After the potting material has hardened to the extent that it loses its fluidity, the centrifugal operation is stopped, and the potting agent is almost completely cured. The ends of each hollow eye bar are opened on the blood inlet/outlet side. At the same time, the inside of the envelopes 11 and 12 is divided into a blood flow path and an oxygen-containing gas flow path via the hollow fiber membrane and the potting material. Incidentally, the above-mentioned potting operation naturally involves the envelope 11,
The same process is performed for the opposite end of 12. FIG. 3 shows two oxygenator envelopes 11, as described above.
12 is placed in a centrifugal device in a straight line and the potting operation is performed on one side at a time.The diameter of the potting part is 10 cm from the center of rotation of the centrifugal device to the potting material 2.
The distance from the center of rotation of the centrifugal device to the potting material 21 when the distance from the center of rotation of the centrifugal device to the potting material 21 is 26.5 cm, and when the potting material 21 is potted simultaneously at both ends with the middle point of the oxygenator envelope 1 as the center of rotation using the conventional method described above. of
Potteng material 21 formed when 7.0 cm
It shows a comparison of the degree of curvature of the inner surface. In this figure, the solid line "x" indicates the case where the potting operation is performed on one side at a time according to the present invention (this is called unilateral centrifugation), and the dotted line "y" indicates the case where the potting operation is performed on both sides simultaneously using the conventional method (this is called the case where both sides are potted simultaneously). (referred to as centrifugation). Note that 22 in this figure indicates the area of the hollow fiber bundle. In addition, the amount of loss in the effective membrane area of the hollow fiber membrane and the loss in the amount of potten material caused by the curvature of the potten material 21 in this case are compared with those in the case where the inner surface of the potten material 21 is completely flat. The numerical values are shown in the table below.

[Table] Specific effects of the invention As detailed above, according to the present invention, the potting operation of the hollow fiber in the artificial lung envelope is performed using a rotation radius longer than the entire length of the artificial lung envelope. Since the curvature of the inner surface of the potten material filled with hollow fibers becomes nearly flat, the loss of effective membrane area of the hollow fiber is reduced, the amount of potten material is also reduced, and the entire oxygenator is made smaller and lighter. , the appearance is also favorable and the sense of value as a product can be improved. Furthermore, since there is little loss in the effective area of the hollow eye bar, the priming volume is also small, which is favorable in terms of priming operation. In the above embodiment, the case where the potting operation is performed in the same way on one side of two oxygenator envelopes is explained, but the invention is not limited to this, and three or more oxygenator lung envelopes are similarly potted on one side. You can also do both at the same time.

[Brief explanation of the drawing]

FIG. 1 is a plan view illustrating a conventional potting method for a hollow-fiber oxygenator, FIG. 2 is a plan view illustrating a potting method according to the present invention, and FIG. 3 is a plan view illustrating a potting method according to the present invention. FIG. 3 is a plan view of a hollow fiber oxygenator illustrating the curved state of the inner curved surface of the material. In the figure, 1... oxygenator envelope, 2... fixed, 3...
...Oxygen gas inlet/outlet, 11, 12...Envelope, 1
3, 14, 15... Fixed plate, 16, 17... Outer end, 18, 19... Oxygen-containing gas introduction hole, 21
...Potten wood, 22...Hollow eye bar bundle.

Claims (1)

[Scope of Claims] 1. A cylindrical envelope that accommodates a large number of hollow eye bars in parallel along the axial direction, and both ends of the envelope with only both ends of the accommodated hollow eye bars open. A blood inlet/outlet port provided at both ends of the cylindrical body is communicated with a potten fixedly held in the body, and a blood inlet/outlet port provided at both ends of the cylindrical body is communicated with the openings at both ends of the hollow fiber, respectively, and a space outside the hollow fiber in the envelope is communicated. In the hollow-eye bar oxygenator comprising a pair of oxygen supply gas inlet/output ports provided in the envelope, the inner facing surfaces of both of the potten portions form a concave surface curved in only two directions, and the concave surface is curved in only two directions. The distance between both outer surfaces of the potten is l, and the thickness of the center of the potten is t.
A hollow fiber oxygenator characterized in that the surface is such that an arc having a radius of curvature of at least lt or more always lies on the concave surface. 2 Hollow fiber has an average pore diameter of 200 to 2000Å
The oxygenator according to claim 1, which is a polypropylene fiber with a porosity of 20 to 85% and an inner diameter of 100 to 300μ. 3 A large number of hollow fibers are arranged in parallel along the axial direction in a cylindrical envelope, a viscous potting material is filled near one end of the envelope to be closed, and the envelope is closed. radially from the center of rotation of the centrifugal device, with the one end of the envelope being the outer side,
The envelope is fixed to the centrifugal device with the other end or the outside thereof as the center of rotation, and then the centrifugal device is rotated, and the centrifugal force at that time causes the potting material to be rotated into the envelope. After the potting material is hardened, the hollow fibers are cut near the ends thereof including the potting material to open the ends of each hollow fiber in the direction of the blood inlet and outlet. A method for manufacturing a hollow eye bar type artificial lung. 4. The manufacturing method according to claim 3, wherein a plurality of envelopes containing potting materials and hollow fibers are arranged in a centrifugal device symmetrically with respect to the rotation axis of the centrifugal device, and potting operations are performed simultaneously.