JPH08141073A - Warming device and hollow fiber membrane type artificial lung having the same - Google Patents

Abstract

PURPOSE: To provide a hollow fiber membrane type artificial lung capable of averting the degradation of gas exchangeability with lapse of time. CONSTITUTION: A warming device 1 is so mounted as to cover a gas leading out side port 33 of this hollow fiber membrane type artificial lung 2 and a heating member 12 is made to generate heat by the electric power inputted from a power supply section. A heat transfer member 11 is heated by this heating member 12 and the gas leading out part 31 and partition walls 24 of the hollow fiber membrane type artificial lung 2 are heated by the heat transfer member 11. On the other hand, the heat of the heating member 12 generating heat is insulated by a heat insulating member 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device used for improving the gas exchange capacity of a hollow fiber membrane oxygenator used for long-term extracorporeal circulation over time and a hollow fiber membrane device including the same. It is about artificial lungs.

[0002]

2. Description of the Related Art In recent years, a centrifugal pump excellent in operability and safety, a cannula that can be inserted into a patient percutaneously, and the like have been developed. The synovial oxygenator has come to be used for extracorporeal assisted circulation such as VA bypass that supports cardiopulmonary function for a long time.

However, in such a hollow fiber membrane oxygenator, there is a problem that the gas exchange capacity with time decreases when used for a long time. That is, water in blood permeates the hollow fiber membrane, flows out into gas to become water vapor, and the water vapor is rapidly cooled by the outside air near the gas outlet,
A phenomenon called so-called wet rung appears, which adheres to the surface of the hollow fiber membrane and reduces the gas exchange capacity.

On the other hand, a hollow fiber membrane type artificial lung in which a temperature holding means is provided on the outer wall surface of the housing on the gas outlet side or a hollow fiber membrane type artificial lung in which a heating wire is embedded in the partition wall of the hollow fiber membrane on the gas outlet side. The lungs were developed.

[0005]

However, since the oxygenator provided with the temperature holding means simply covers the outer wall surface of the housing forming the gas outlet with the foam material, the heat retaining effect is maintained for a long time. Is difficult. Further, the artificial lung in which the heat wire is embedded in the partition wall can be heated for a long period of time because the current is applied to the heat wire by the energizing means to generate heat, but the heat transfer and heat insulation effects are low, so the temperature is high. You have to keep it. Therefore, maintaining a constant temperature for a long time may affect blood because of the high temperature.

The present invention has been made in view of the above-mentioned conventional problems, and effectively heat-transfers and insulates to avoid a decrease in gas exchange capacity over time, and to wet for a long time. An object of the present invention is to provide a heating device capable of preventing the rung phenomenon and a hollow fiber membrane type artificial lung including the heating device.

[0007]

This object is achieved by the heating device of the present invention and the hollow fiber membrane type artificial lung provided with the heating device.

That is, the warming device of the present invention is a warming device which is attached to a hollow fiber membrane-type artificial lung to maintain the gas outlet of the oxygenator at a constant temperature. A heat transfer member for transmitting heat, a heating member provided in contact with the heat transfer member for heating the heat transfer member, a power supply unit for supplying electric power to the heating member, and the heating unit. It is characterized in that it is provided in contact with the member and comprises a heat insulating member for holding the temperature generated in the heating member.

Further, it is preferable that the heating device has a bottomed cylindrical shape in which the heat transfer member, the heating member and the heat insulating member are laminated.

Further, in the heating device, the heat transfer member and the heat insulating member have a bottomed cylindrical shape, one surface of the heating member is positioned in contact with the inner bottom surface of the heat insulating member, and the other surface is Is preferably in contact with the outer bottom surface of the heat transfer member.

Further, the warming device is provided with an artificial lung attachment portion for attaching to the artificial lung so as to cover the partition wall and the gas outlet portion of the artificial lung, and a gas outlet for attaching the gas outlet of the artificial lung. It is preferable to provide a mounting portion.

The hollow fiber membrane type artificial lung provided with the heating device of the present invention comprises a housing, a large number of porous hollow fiber membranes housed in the housing, and both ends of the hollow fiber membrane. A partition for liquid-tightly fixing to both ends of the housing, a blood inlet and a blood outlet communicating with a blood chamber formed by the partition, the outer surface of the hollow fiber membrane and the inner wall of the housing, and one end of the housing A hollow fiber membrane-type artificial lung comprising a gas inlet provided on the side and communicating with the inside of the hollow fiber membrane, and a gas outlet provided on the other end side of the housing and communicating with the inside of the hollow fiber membrane. The heating device is provided at an end of the housing on the gas outlet side.

[0013]

In the above structure, the heating device of the present invention and the hollow fiber membrane-type artificial lung including the heating device are equipped with the heating device on the bottom surface of the hollow fiber membrane-type artificial lung, and the power input from the power supply unit is supplied. The heating member generates heat, the heating member heats the heat transfer member, the heat transfer member transfers heat to the bottom surface of the hollow fiber membrane-type artificial lung, and the gas outlet of the artificial lung can be heated. on the other hand,
The heat of the heating member that has generated heat can be insulated by the heat insulating member. Therefore, it is possible to use the hollow fiber membrane type artificial lung for a long time.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The warming device of the present invention and the hollow fiber membrane-type artificial lung equipped with the same will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

First, the heating device of the present invention will be described with reference to FIG.
2 and FIG. FIG. 1 is an external view of a heating device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the heating device according to an embodiment of the present invention.

In the figure, a heating device 1 of the present invention includes a heat transfer member 11 for covering the gas outlet of a hollow fiber membrane oxygenator and transferring heat, and a heat transfer member provided in contact with the heat transfer member 11. 11
A heating member 12 for heating the heating member 12, a power supply unit 14 for supplying electric power to the heating member 12, and a heat insulating member 13 provided in contact with the heating member 12 for holding the temperature generated in the heating member 12. . The heat transfer member 11, the heating member 12, and the heat insulating member 13 are laminated. The heat transfer member 11 and the heat insulating member 13 have a cylindrical shape with a bottom, and the heating member 12 has one surface in contact with the inner bottom surface of the heat insulating member 13 and the other surface on the outer bottom surface of the heat transfer member 11. Located close to each other. Further, the warming device 1 includes an artificial lung attachment part 1 for attaching the artificial lung so as to cover the partition wall and the gas outlet of the artificial lung.
5 and a gas outlet port mounting portion 16 for mounting the gas outlet port of the artificial lung. The heating device 1 has a height that covers the gas outlet and the partition wall of the artificial lung, or has a height higher than that. In addition, the artificial lung attachment part 15
Is formed in conformity with the shape of the gas outlet port of the hollow fiber membrane-type oxygenator, and the gas outlet port attachment portion 16 is formed in conformity with the position of the gas outlet port of the hollow fiber membrane-type oxygenator.

The power supply unit 14 is connected to a temperature control device (not shown), and the temperature control device guides an electric current from an energizing means (for example, a DC power supply) so that the temperature becomes a predetermined temperature. After controlling the electric current, the electric power is supplied to the heating member 12 via the power supply unit 14. Then, the heating member 12 generates heat by the supplied electric power, and the heating member 12 heats the heat transfer member 11,
The heat transfer member 11 heats the entire gas outlet and partition of the hollow fiber membrane-type artificial lung. On the other hand, the heat generated by the heating member 12 is insulated by the heat insulating member 13. Therefore, it is possible to use the hollow fiber membrane type artificial lung for a long time.

The shape of the heating device 1 is not particularly limited as long as it covers the gas outlet portion and the partition wall of the artificial lung, but may be a shape that matches the gas outlet port of the artificial lung. It is preferable, specifically, to have a bottomed cylindrical shape, and particularly preferable to have a bottomed cylindrical shape.

The material of the heat transfer member 11 is preferably one having a high thermal conductivity, such as aluminum, copper, iron,
Examples thereof include aluminum alloys and zinc alloys, but aluminum is particularly preferable because it is easy to process with a light weight and has high thermal conductivity. The thickness of the heat transfer member 11 is about 0.1 mm to 100 mm, preferably 1.0 m.
m-5.0 mm, particularly preferably 2.0 mm, when the wall thickness is 0.1 mm or less, there is concern about the strength, and when it is 100 mm or more, a large amount of heat energy for heating is required, An economical burden is imposed because efficient heat transfer cannot be performed.

The heating member 12 may have a shape similar to that of the bottom surface of the artificial lung as shown in the figure, or may have a shape similar to that of the gas outlet port of the artificial lung. For example, a silicon rubber heater, Far-infrared heaters, film type heaters and the like can be mentioned, but it is particularly preferable to use a silicon rubber heater because it is a thin sheet, has excellent flexibility, and can be easily processed into a required shape. Further, in order to reduce the size of the heating device 1, it is preferable that the thickness of the heating member 12 is as small as possible and an energy saving type capable of efficiently heating the heating member 12, specifically, a thickness of about 0.5 mm to 1.5 mm. It is preferably thick.

The heat insulating member 13 has a low thermal conductivity,
The material is not particularly limited as long as it can prevent the dissipation of heat, but for example, polyethylene, polyurethane,
Examples thereof include foams made of polymer materials such as polystyrene, polyethylene, and polypropylene. However, foamed polyethylene is particularly preferable because it has a high heat insulating effect and is easily processed. The thickness of the heat insulating member 13 is 0.1 mm to 1
About 00 mm, preferably about 1.0 mm to 10 mm,
Particularly preferably, it is 5.0 mm, and when the wall thickness is 0.1 mm or less, the heat insulating effect is poor, and it is difficult to sufficiently prevent heat dissipation, and when it is 100 mm or more, the heating device 1 has The size is large, and it is difficult to attach it to an artificial lung arranged in a circuit such as a cardiopulmonary bypass circuit.

The temperature control device controls the temperature of the gas outlet of the artificial lung so as to be maintained at the same as or slightly higher than the temperature of blood. For example, a chromel alumel connected to the heating member 12 or Thermocouples such as iron and constant,
Alternatively, a signal generated from a resistance temperature sensor such as platinum or nickel is used as a control method for ON / OFF operation, fine operation, PDI operation, or the like.

Next, a hollow fiber membrane type artificial lung equipped with the heating device of the present invention will be described with reference to FIG. FIG.
It is sectional drawing of the hollow fiber membrane type oxygenator provided with the heating apparatus which concerns on the Example of this invention.

In the figure, a hollow fiber membrane type artificial lung 4 equipped with a heating device of the present invention is shown as a hollow fiber membrane type artificial lung 2 and a heating device 1.
The hollow fiber membrane type artificial lung 2 comprises a housing 21
A large number of porous hollow fiber membranes 22 housed in the housing 21, partition walls 23 and 24 for liquid-tightly fixing both end portions of the hollow fiber membranes 22 to both end portions of the housing 21, and partition walls 23 and 2.
4, an outer surface of the hollow fiber membrane 22 and a blood chamber 25 formed by the inner wall of the housing 21, the blood inlet 26 and the blood outlet 27 communicating with each other, and the inside of the hollow fiber membrane 22 provided at one end of the housing 21. The gas inlet 28 communicates with the gas outlet 29 provided at the other end of the housing 21 and communicates with the inside of the hollow fiber membrane 22. The heating device 1 is provided at the end of the housing 21 on the gas outlet 31 side. Is equipped with.

More specifically, the hollow fiber membrane-type artificial lung 2 is housed in a housing 21 having a blood inlet 26, a blood outlet 27, and a restraining portion 34 at an intermediate portion, and is housed in the housing 21 in the axial direction. And a partition wall 23, 24 that holds both ends of the hollow fiber membrane in the housing 21 in a liquid-tight manner. The inside of the housing 21 is divided into a gas chamber and a blood chamber. A cap-shaped gas introduction port 32 having a gas introduction port 28 communicating with a gas chamber which is an internal space of the hollow fiber membrane 22 is provided above the partition wall 23 on one side which is an end of the housing 21, and the other side. A cap-shaped gas lead-out port 33 having a gas lead-out port 29 that is provided below the partition wall 24 and communicates with the internal space of the hollow fiber membrane 22 is attached. Then, the gas introduced from the gas introduction port 28 flows into the gas chamber from the gas introduction part 30 formed by the partition wall 23, exchanges gas with the blood in the blood chamber 25, and is formed by the partition wall 24. It flows out from the gas outlet 31 and is led out from the gas outlet 29. Further, the heating device 1 described above is mounted so as to cover the gas outlet port 33. The heating device 1 covers the gas flow path of the gas outlet 29 from the partition wall 24 to keep the temperature of the gas outlet 31 where the wet rung phenomenon is likely to be constant.

The hollow fiber membrane 22 may be either a porous membrane or a diffusion membrane (eg, silicon), but is preferably a porous membrane. The inner diameter of the porous hollow fiber membrane is 100
˜1000 μm, preferably 10 to 300 μm, porosity 20 to 80%, preferably 30 to 60%, and pore size 0.05 to 5 μm, preferably 0.01 to 1 μm.
Those of m can be preferably used. Furthermore, as the material used for the porous film, a hydrophobic polymer material such as polypropylene, polyethylene, polysulfone, polyacrylonitrile, polytetrafluoroethylene, or cellulose acetate is used, and preferably a polyolefin resin, Particularly preferred is polypropylene, which has fine pores formed in the wall by a stretching method or a solid-liquid phase separation method.

The housing 21 is formed of, for example, a transparent body whose inside can be easily confirmed. Inside the housing 21, approximately 1,000 to 50,000 are arranged in parallel in the axial direction.
A large number of hollow fiber membranes 22 of a book are accommodated, and further, the hollow fiber membranes 22 are fixed in a liquid-tight state by partition walls 23 and 24 in a state where each end is opened in the housing 21, The gas introduction part 30 and the gas derivation part 31 are formed. The partition walls 23 and 24 are made of a potting agent such as polyurethane or silicone rubber, and are used for the housing 2
The part sandwiched by the partition walls 23 and 24 in 1 is the hollow fiber membrane 2
2 is divided into a gas chamber on the inner side and a blood chamber 25 on the outer side of the hollow fiber membrane 22.

A gas inlet port 32 having a gas inlet 28 is attached to the outside of the partition wall 23 on one side, and a gas outlet port 33 having a gas outlet 29 is attached to the outside of the partition wall 24 on the other side. These are the tightening ring or each port 32, 3 without using the tightening ring.
3 is fused to the housing 21 using ultrasonic waves, high frequency waves, etc.,
It is attached by adhesion using an adhesive or by mechanical fitting.

(Example 1) An experiment circuit was prepared using the hollow fiber membrane-type artificial lung 2 shown in FIG. 3 (without a heating device attached) to determine the carbon dioxide gas removal ability and the gas introduction pressure. The change with time was measured.

In this embodiment, the hollow fiber membrane has an inner diameter of about 200 μm, a porosity of about 40%, and a pore diameter of about 0.1 μm.
2000 polypropylene hollow fibers were used. Also, using bovine blood having a hemoglobin concentration of 12 g / dl and a temperature of 37 ° C., the blood flow rate is usually 4.0 l / min,
The gas was circulated in the experimental circuit at a flow rate of 2.0 l / min, the gas was changed to carbon dioxide containing nitrogen immediately before measurement, and the blood was converted into venous blood to a flow rate of 4.0 l / min. The room temperature was maintained at a constant temperature (25 ° C).

Immediately after the start of circulation, 6 hours later, and 11
After a lapse of time, the carbon dioxide gas removing ability and the gas introduction pressure were measured. Table 1 shows the results.

[0032]

[Table 1]

From Table 1, it can be seen that the hollow fiber membrane type artificial lung has a decreased ability to remove carbon dioxide over time. Further, it can be seen that the gas introduction pressure increases as the carbon dioxide gas removal ability decreases. It is considered that this is because the dew condensation water was retained inside the hollow fiber due to the wet rung phenomenon in the gas outlet of the hollow fiber membrane-type artificial lung.

Example 2 An experimental circuit was prepared using the hollow fiber membrane-type artificial lung 4 equipped with the heating device of the present invention shown in FIG. 3 and the time-dependent change of gas introduction pressure was measured. .

In this embodiment, the same hollow fiber membrane-type artificial lung 2 as the artificial lung used in Example 1 is used, and the heating device 1 is made of aluminum as shown in FIG. Has a thickness of 2.0 mm, a heating member 12 connected to the temperature control device through a power supply unit 14 and made of a silicone rubber heater, and a foamed polyethylene having a thickness of 5.0 mm. A heat insulating member 13 was used. The temperature of the heating member 12 was set to 37 ° C. In addition, distilled water, which is more likely to become saturated steam than blood, is used as a circulating fluid, and the temperature is 37 ° C. on the blood side and the flow rate is 4.
Circulate at 0 l / min and flow air on the gas side at 4.0 l
It was circulated at a speed of / min. Also, the room temperature is a constant temperature (25 ° C)
Kept at.

Immediately after the start of circulation and 6 hours later, the gas introduction pressure was measured. The results are shown in Table 2.

(Comparative Example) Using the hollow fiber membrane-type artificial lungs 5 and 6 shown in FIGS. 4 and 5, the changes in gas introduction pressure with time were measured under the same conditions as in Example 2.

Here, a hollow fiber membrane type artificial lung of a comparative example will be described with reference to FIGS. 4 and 5. FIG. 4 is a cross-sectional view of a hollow fiber membrane-type artificial lung including only a heat insulating member according to a comparative example of the present invention, and FIG. 5 is a hollow fiber including a heating member and a heat insulating member according to a comparative example of the present invention. It is a sectional view of a membrane oxygenator.

The oxygenator of Comparative Example 1 was the oxygenator 2 of Example 1.
The hollow fiber membrane oxygenator (without a heating device) shown in FIG. Therefore, Comparative Example 1 will not be described in detail. Then, Comparative Example 2
As shown in FIG. 4, the hollow fiber membrane-type artificial lung 5 including only the heat insulating member is obtained by attaching only the heat insulating member 51 to the artificial lung 2 of the first embodiment. The heat insulating member 51 is made of foamed polyethylene and has a thickness of 5.0 mm, and is mounted so as to cover the gas outlet port 33 of the artificial lung 2 as in the heat insulating member 13 of the second embodiment. Then, the hollow fiber membrane type artificial lung 6 including the heating member and the heat insulating member of Comparative Example 3
As shown in FIG. 5, the heating member 61 and the heat insulating member 62 are attached to the artificial lung 2 of the first embodiment. The heating member 61 is attached to the oxygenator 2 so as to cover the partition wall 24 on the gas outlet 31 side and heats the gas outlet 31 with an electric current supplied from the outside. Also, the heat insulating member 6
No. 2 is the same as the heat insulating member 13 of Example 2 and the heat insulating member 51 of Comparative Example 2, and the gas outlet port 33 of the artificial lung 2
Is mounted so as to cover the heating member 61, and heat generated by the heating member 61 is insulated. As the heating member 61, a film type heater was used and the temperature was set to 42 ° C.

Then, Comparative Example 1, Comparative Example 2 and Comparative Example 3
Using the hollow fiber membrane-type artificial lung of the present invention, the gas introduction pressure was measured with time in the same manner as in Example 2. The results are shown in Table 2 together with Example 2.

[0041]

[Table 2]

As is clear from Table 2, the hollow fiber membrane-type artificial lung 4 of Example 2 has no pressure difference immediately after the start of circulation and 6 hours after the start of circulation. It can be seen that the hollow fiber membrane-type artificial lung 4 provided with the same can prevent the wet rung phenomenon for a long time without a decrease in gas exchange capacity over time. On the other hand, in the artificial lung 2 not equipped with the heating device of Comparative Example 1, the pressure of 30 mmH ₂ O is increasing, and it is clear that the gas exchange capacity is decreasing with time. Also, in the artificial lung 5 provided with only the heat insulating member of Comparative Example 2, a pressure increase of 16 mmH ₂ O can be confirmed, so it is understood that it is difficult to prevent the wet rung phenomenon for a long time only with the heat insulating member. Further, in the artificial lung 6 including the heating member and the heat insulating member of Comparative Example 3, the pressure increase of 8 mmH ₂ O was confirmed even though the temperature of the heating member 61 was set to 5 ° C. higher than the temperature of the circulating fluid. It was As a result, in the artificial lung 6 of Comparative Example 3, since the position of the heating member was not in the proper position and the heat transfer member was not used, the heat generated by the heating member was not effectively transferred to the gas outlet. I understand.

[0043]

As described above, according to the heating device of the present invention and the hollow fiber membrane-type artificial lung including the heating device, the heating device of the present invention can be used in the gas outlet side of the hollow fiber membrane-type artificial lung. By mounting on the bottom part of the, the heat generated by the heating member is effectively transferred to the gas outlet of the artificial lung by the heat transfer member,
On the other hand, since the heat generated by the heating member is effectively insulated by the heat insulating member, it is possible to avoid a decrease in gas exchange capacity over time and prevent the wet rung phenomenon for a long time. Further, since the heating device of the present invention can be detached from the hollow fiber membrane type artificial lung which is disposable and can be used for a plurality of times, the cost can be reduced as compared with the device attached to the artificial lung.

Further, since the heating device of the present invention has a bottomed cylindrical shape in which a heat transfer member, a heating member and a heat insulating member are laminated, heat transfer and heat insulation can be performed more effectively. Time wet rung phenomenon can be prevented.

Further, in the heating device of the present invention, the heat transfer member and the heat insulating member have a bottomed cylindrical shape, and one surface of the heating member is positioned in contact with the inner bottom surface of the heat insulating member and the other surface is transferred. By being in contact with the outer bottom surface of the heat member, heat transfer and heat insulation can be performed more effectively, so that the wet rung phenomenon can be prevented for a long time.

The warming device of the present invention is also equipped with an artificial lung attachment portion for attaching to the artificial lung so as to cover the partition wall and the gas outlet portion of the artificial lung, and a gas guide for attaching the gas outlet port of the artificial lung. By providing the outlet mounting portion, heat transfer and heat insulation can be performed more effectively, so that the wet rung phenomenon can be prevented for a long time.

[Brief description of drawings]

FIG. 1 is an external view of a heating device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a heating device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a hollow fiber membrane-type artificial lung provided with a heating device according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a hollow fiber membrane-type artificial lung including only a heat insulating member according to a comparative example of the present invention.

FIG. 5 is a cross-sectional view of a hollow fiber membrane-type artificial lung including a heat insulating member and a heating member according to a comparative example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating device 11 Heat transfer member 12 Heating member 13 Thermal insulation member 14 Power supply part 15 Artificial lung attachment part 16 Gas introduction port attachment part 2 Hollow fiber membrane type artificial lung 21 Housing 22 Hollow fiber membrane 23, 24 Partition wall 25 Blood chamber 26 Blood inlet 27 Blood outlet 28 Gas inlet 29 Gas outlet 30 Gas inlet 31 Gas outlet 31 Gas inlet port 33 Gas outlet port 34 Restraint portion 4 Hollow fiber membrane type artificial lung equipped with heating device 5 Hollow fiber membrane type artificial lung provided only with heat insulating member 6. Hollow fiber membrane type artificial lung provided with heating member and heat insulating member

Claims (2)

[Claims] 1. A heating device, which is attached to a hollow fiber membrane-type artificial lung, for maintaining the gas outlet of the oxygenator at a constant temperature, the heat transfer device covering the vicinity of the gas outlet and transferring heat. A heat member, a heating member provided in contact with the heat transfer member to heat the heat transfer member, a power supply unit for supplying electric power to the heating member, a heat supply member provided in contact with the heating member, A heating device comprising: a heat insulating member for holding the temperature generated in the heating member. 2. A housing, a large number of porous hollow fiber membranes housed in the housing, partition walls for fixing both ends of the hollow fiber membranes to both ends of the housing in a liquid-tight manner, the partition wall and the partition wall. A blood inlet and a blood outlet that communicate with a blood chamber formed by the outer surface of the hollow fiber membrane and the inner wall of the housing, and a gas inlet that is provided at one end of the housing and that communicates with the inside of the hollow fiber membrane. A hollow fiber membrane type artificial lung comprising a gas outlet provided at the other end of the housing and communicating with the inside of the hollow fiber membrane, wherein the gas outlet side end portion of the housing comprises: A hollow fiber membrane-type artificial lung, comprising the heating device according to 1.