DD231988A5 - HEAT EXCHANGER AND BLOOD OXYGEN DEVICE THEREFORE PROVIDED - Google Patents

Abstract

The invention relates to a heat exchanger using hollow fibers (1, 15, 39) of organic polymers as heat transfer tubes, and a Blutoxygenator device from a Blutoxygenator, which is connected to the vorerwaehnten heat exchanger. The present invention relates to a small and light blood oxygenator of a hollow fiber membrane type blood oxygenator having the pre-expanded heat exchanger incorporated therein to form an integral unit, the blood oxygenator having excellent gas exchange and heat transfer performance. Fig. 1

Description

Heat exchanger and blood oxygenator device provided therewith

FIELD OF THE INVENTION:

The invention relates to a heat exchanger in which hollow fibers of an organic polymer are used as heat exchange tubes which are capable of effectively different liquids, including liquids such as water or

Blood, and gases, such as air, oxygen or nitrogen, to heat or cool. The invention also relates to a blood oxygenator apparatus equipped with such a heat exchanger. 10

CHARACTERISTICS OF THE KNOWN TECHNICAL SOLUTION:

Numerous types of heat exchangers are known for bringing fluids from a high temperature to a lower temperature. Most heat exchangers

have a multi-tube construction. As the material for the heat exchange tubes in heat exchangers of the multi-tube type, in particular, metals having a good heat conductivity are suitable. Among other things, stainless steel pipes have been used frequently because they are very resistant to corrosion by the fluids used in the heat exchange. An effective way of introducing stainless steel tubing into a heat exchanger is to mount it with an organic resin, but the large difference in hardness between the stainless steel tubing and the potting material makes it difficult to properly fit the final surfaces of the potted parts to process. That is, the ends of the tubes have exposed sharp edges which tend to destroy these particles in the treatment of particles such as fluids containing blood cells. To avoid this difficulty, the use of stainless tubes, the ends thereof, is currently underway covered with soft material, studied, but so far no significant improvements have been achieved.

Heat exchangers are used as a means to cause heat exchange in different liquids. For example, using a blood oxygenator to perform surgery on the heart, a heat exchanger is generally connected to the blood-gas exchange circuit, including the blood oxygenator, because of the need

It is necessary to set the body temperature of the patient at the beginning of the operation to a low level and it is also necessary to adjust the temperature of the blood, in which a gas exchange was made by means of the blood oxygenator, to the body temperature of the patient before it returns to the patient's body is supplied. There may also be a need to restore the patient's lower body temperature to normal after surgery.

In hospitals, this blood-gas exchange circuit is generally arranged by exposing the blood oxygenator to a separate heat exchanger, ζ.B. Circulation pipes, connects. However, such an arrangement has the disadvantage that the arrangement of the blood-gas exchange circuit is cumbersome for the user and there is the risk of incorrectly connecting the circuit and that additional space is required for the circuit. Since the blood oxygenator and the heat exchanger are two separate residence points for the blood and there is a need to use circuit tubes to connect them, the initially accumulating blood volume which is circulated in the first phase of surgery is extremely large and must have the various circulatory components be degassed separately. As a result, such an arrangement is also very complicated with regard to the overall operation.

As a means to avoid these disadvantages, one has

already uses blood oxygenator devices from a Blutoxygenator, which is integrally connected to a heat exchanger (see, for example, Japanese Patent Publication 29 * 82/1980 and JP-OS 39854/1982). In these blood oxygenator devices, however, the heat transfer member in the heat exchange portion is formed of metal such as stainless steel having a good thermal conductivity. In the case of stainless steel tubes, there is now the added difficulty that during processing of the tube ends, debris remains in the tubes and contaminates the blood, and that stainless steel is also able to react with some components of the blood having a more complicated composition. There is therefore a continuing need for heat exchangers that do not experience these difficulties.

Furthermore, a number of blood oxygenators have been proposed using hollow fiber membranes, e.g. in U.S. Patents 2,972,349, 3,794,468, 4,239,729 and 4,374,802.

In these blood oxygenators, hollow fibers of a homogeneous membrane of a gas permeable material, such as silicon or hollow fibers of a microporous membrane of a hydrophobic polymer material, such as polyolefins, are used to bring the blood in contact with gas through the medium of the hollow fiber membrane and thereby effect the gas exchange , There are two types of blood oxygenators: the inner

perfusion type, in which the blood flows through the holes of the hollow fibers, while gas flows past the outside of the hollow fibers, and the Außenperf usionstyp in which, conversely, the gas is passed through the holes in the hollow fibers, while the blood is passed outside the hollow fiber ,

In most known blood oxygenators, a cylindrical housing is simply packed with a large number of hollow fibers of semipermeable membranes for use in gas exchange such that the hollow fibers are aligned parallel to the axis of the cylindrical housing. However, blood oxygenators having this structure have a low gas exchange rate per unit area of the hollow fiber membrane, whether they are of the inner perfusion type or the outer perfusion type. An improved form of the outer perfusion type, according to US Pat. No. 3,794,468, consists of a blood oxygenator, in which hollow tubings of a semipermeable membrane are wound around a hollow cylindrical core with a large number of pores in the wall and which are located in a housing in which the blood is allowed to flow from the cavity of the core through its pores, while allowing the gas to flow through the holes in the hollow pipes.

In internal perfusion type blood oxygenators in which the gas exchange is effected by the blood flowing through the holes of the hollow fibers while gas flows outside the hollow fibers

often a channeling of the blood. However, since the blood flows laminar through the holes in the hollow fibers, it is necessary to reduce the inner diameter of the hollow fibers to increase the rate of oxygenation (i.e., the rate of oxygen transfer per unit area of the membrane). For this purpose, hollow tubes of semipermeable membranes having an inside diameter of the order of 150 to 300 μm have been developed for use in blood oxygenators.

However, as long as the blood flows laminarly, one can not significantly increase the oxygenation rate by decreasing the inside diameter. Moreover, if the inner diameter is made smaller, the risk of blood clots forming (ie, blockage of the bore due to coagulation of blood) and / or increased pressure loss through the oxygenator will result in greater hemolysis of the blood This causes significant problems in practice. In addition, since a blood oxygenator generally employs tens of thousands of hollow fibers made of a semipermeable membrane packed into a bundle or bundles, it is especially necessary to uniformly distribute the gas on the outer surface of each of these numerous hollow fibers. With an uneven distribution of the gas, the Kphlendioxid desorptionsrate decreases (i.e., the carbon dioxide transition rate per unit area of the membrane). On the other hand, in a blood oxygenator of the external perfusion type in which the gas passes through the

Holes in the hollow fibers flow, while the blood flows past the outside of the hollow fibers, the gas is distributed evenly, while one can assume that the blood flows turbulent. However, these oxygenators suffer from unsatisfactory oxygenation due to channeling of the blood and / or blood coagulation at the sites where the current stagnates. Although the blood oxygenator in the aforementioned US Patent 3,794 4 has brought about improvements in this respect, there is still a drawback that the first blood volume is extremely large and causes a considerable pressure loss in the oxygenator. Therefore, there is still a need for an improved blood oxygenator.

OBJECT OF THE INVENTION:

The object of the invention is to provide a heat exchanger having a high heat exchange efficiency, wherein an organic polymer previously thought to be unsuitable for use in heat exchange walls due to its low thermal conductivity, as a heat exchange part in Can use a hollow fiber form.

Another object of the invention is to provide a heat exchanger in which the

Hardness difference between the barrier member formed of an organic material and the heat exchange tubes is small enough to allow easy workability of the ends of the heat exchange tube.

A further object of the invention is to provide a heat exchanger of heat exchange tubes which have neither exposed sharp edges nor ends and in which also no metallic residues can remain, so that such a heat exchanger is particularly suitable for the treatment of fragile particles containing liquids, like blood, is suitable.

The object of the present invention is further to provide a blood oxygenator device composed of a combination of a blood oxygenator in which hollow fiber membranes are used as a gas exchange membrane and a heat exchanger using hollow fibers as heat exchange tubes.

Finally, it is also an object of the invention to show a blood oxygenator apparatus constructed to provide a blood oxygenator with high oxygenation and carbon dioxide desorption rates, with little standstill or channeling of the blood, with a small and light heat exchanger having a large volume Heat exchange performance combined to form an integral unit, giving a compact, cheap and simple

Structure in which no complicated steps are required during manufacture and wherein such a device is also easy to use.

DISCLOSURE OF THE INVENTION OF THE INVENTION:

According to one embodiment of the invention, there is provided a heat exchanger of (1) a housing, (2) a bundle of hollow fibers of an organic polymer, wherein the bundle of hollow fibers is disposed and packed within the housing such that at both ends of the housing a liquid seal is made, (3) a heat exchange chamber on the outside of the hollow fibers, and (4) a fluid inlet chamber and a fluid outlet chamber provided respectively at the respective ends of the hollow fiber bundle so as to communicate with the bores in the hollow fibers.

According to another embodiment of the invention, a blood oxygenator in which the heat exchanger is mounted is shown. This blood oxygenator device has a heat exchange part for controlling the blood temperature and a gas exchange part in which the gas exchange with the blood takes place, and is characterized in that (1) the heat exchange part is a hollow fiber bundle made of an organic

Polymer as a heat transfer member, wherein the fiber bundle · is inserted and packed in the heat exchange member such that there is a liquid tight seal at both ends of this heat exchange member, and (2) a fluid inlet chamber and a fluid exhaust canister are provided at the respective ends of the hollow fiber bundle in that they communicate with the holes in the hollow fibers.

According to another embodiment of the invention, there is provided an improved blood oxygenator apparatus in which the internal structure of the improved hollow fiber membrane type blood oxygenator is accommodated as a gas exchange portion in the above-mentioned blood oxygenator apparatus with the gas exchange portion in the form of an integral unit in a single housing , This biotoxygenator device comprises (1) a housing having a blood inlet, a blood outlet, a gas inlet, a gas outlet, a heat exchange medium inlet, and a heat exchange medium outlet and a contact chamber, the contact chamber having both flow channels for the blood passing through orifice cells and a plurality of compartments separated by the blood flow channels, (2) a first bundle or bundles of high-abundance hollow fiber membranes of high-fiber membranes for use in fixed-end gas exchange and (3 a second bundle or bundles of hollow fiber membranes of a large number of hollow fibers for use in heat exchange and with fixed ones

Ends, wherein the first and second bundles of the hollow fiber membranes are distributed in separate compartments so as to be substantially parallel to the throttling sites and the respective ends of the first bundle of the hollow fiber membranes with the gas inlet and the gas outlet and the respective ends of the second bundle the hollow fiber membranes communicate with the heat exchange medium inlet and the heat exchange medium outlet. 10

Fig. 1 shows a schematic

Section of a heat exchanger according to the invention;

Figs. 2 and 3 show schematic sections of a

another embodiment of the inventive heat exchanger;

Fig. 4 shows a schematic section

a blood oxygenator device,

which is equipped with a heat exchanger according to the invention;

FIG. 5 shows a partially plan view

cut according to another off

guide form of a Blutoxygenator device according to the invention;

Fig. 6 shows a vertical section

0 of a preferred embodiment

a blood oxygenator device,

in which a heat exchanger according to the present invention is incorporated;

Fig. 7 shows a partial section of

Blood oxygenator device according to Fig. 6;

Fig. 8 is a graph

0 and shows the heat exchange line

tion of the invention Blutoxygenator device; and

Fig. 9 is a graph

and shows the oxidation performance

the inventive blood oxygenator device.

The structure of the inventive heat exchanger will now be explained in more detail with reference to FIG. 1.

As shown in Fig. 1, the heat exchanger comprises hollow fibers 1 for use for heat exchange, a housing 2 for receiving the hollow fibers and a heat exchange chamber 3. A barrier member 4 serves to seal the heat exchange chamber 3 from the open ends of the hollow fiber 1 and from a fluid inlet (or outlet) chamber 5 and a fluid outlet (or inlet) chamber 6, both communicating with the cavities in the hollow fibers

in addition, a fluid inlet 7 and a fluid outlet 8, both of which communicate with the heat exchange chamber 3.

Referring to Figs. 2 and 3, further embodiments of a heat exchanger according to the invention are shown. In contrast to the heat exchanger in Fig. 1, these embodiments have a bundle of hollow fibers 1 as straight lines

10. extend in the housing 2. In the embodiment of Fig. 3, a fluid distribution chamber 9 and a F.luidsammelkammer 10 between the fluid inlet 7 and the region which is occupied by the hollow fibers 1 and between the fluid outlet 8 and the region which is occupied by the hollow fiber 1, respectively provided to ensure that the flowing on the outside of the hollow fiber 1 fluid occupies a Fliesspfad which is substantially perpendicular to the hollow fiber 1.

In the production of a heat exchanger according to the invention, the material for the hollow fibers from which the heat transfer tubes are formed may be selected from a variety of organic polymers. Examples of these are polyolefins and fluorinated polyolefins such as polypropylene, polyethylene, poly-4-methyl-1-pentene, polyvinylidene fluoride and polytetrafluoroethylene; acrylonitrile; Cellulosic polymers; Polyamides and polyimides; Polyester; Silicone resins; Polymethyl methacrylate and its analogs; polycarbonates; as well as polysulfones. Amongst other things

one can use organic polymers having a thermal conductivity of 1.0 χ 10 ~ ⁵ to 50.0 χ 10 ^-4 cal / cm · sec · ⁰ C for producing a plastic heat exchanger, which in its heat exchange efficiency, with the usual heat exchangers where metallic tubes are used can quite measure.

In order to increase the heat exchange efficiency of the heat exchanger according to the invention, it is preferable to use hollow fiber membranes having an inner diameter of about 50 to about 1,000 μm and a wall thickness of about 2 to 200 μm.

If the inner diameter of the hollow fibers used is too small, a large pressure loss can occur during operation and the sealability of the flow paths is thereby reduced. On the other hand, when the inner diameter of the hollow fibers is too large, the fluid flowing through the holes in the hollow fibers has a small heat transfer coefficient, and the relative volume occupied by the hollow fibers per unit of the heat transfer surface increases, thereby resulting in Reduction of heat transfer efficiency and enlargement of the heat exchanger. Furthermore, the wall thickness of the hollow fibers should be as thin as possible in order to reduce the heat transfer resistance and to allow the formation of a heat exchanger with a compact size. Very particularly preferred in terms of

Strength and handleability of the hollow fibers which can be used for the present invention are those having an inner diameter of 150 to 500 μΐη and a wall thickness of 10 to 100 μΐη. 5

In the embodiment shown in Fig. 1, the heat exchanger according to the invention can be constructed by using hollow fibers 1 of an organic polymer of the aforementioned kind and accommodating them in the housing 2. After selecting a barrier member 4 made of a potting material selected from, for example, epoxy resins, unsaturated polyester resins and polyurethane resins, the end surfaces of the barrier member 4 are processed so that the hollow fibers have open ends. In addition, one still sees a Fluideiniasskammer 5 and 6 before a Fluidauslasskammer.

The inventive heat exchanger allows easy processing of the end surfaces of the barrier member, because the difference in hardness between the barrier member and the hollow fibers is very low in comparison to heat exchangers, in which metal tubes are used as a heat exchange part. The open ends of the hollow fibers are so soft that, when using this heat exchanger for the treatment of blood, the cells contained in the blood are in no way damaged by any edges formed at the ends of the hollow fibers. In addition, the heat exchange efficiency of this heat exchanger is quite comparable

with a heat exchanger with metallic pipes.

Hereinafter, the blood oxygenator apparatus in which a heat exchanger according to the present invention is incorporated will be explained in detail with reference to the drawings.

The blood oxygenator apparatus equipped with a heat exchanger according to the invention consists of a heat exchange part A, in which a heat exchange of the blood takes place, and a gas outlet part B, in which a gas exchange takes place with the blood. The heat exchange part A may be of the inner perfusion type in which the blood flows through the holes of the hollow fibers used for the heat exchange, or of the outer perfusion type in which the blood flows on the outside of the hollow fibers used for the heat exchange. The embodiment according to FIG. 4 shows the type of internal perfusion, while the embodiment shown in FIG. 5 shows the type of external perfusion.

The inner-perfusion type heat exchange part A shown in Fig. 4 comprises a housing 11, a blood inlet (or outlet) 12, a blood flow channel 13, hollow fibers 15 for heat exchange, a casting 14 for fixing the hollow fiber 15 in the housing 11 and for separating the flow space for the heat exchange medium from the blood flow space, a heat exchange medium inlet (or outlet) 16,

and a heat exchange medium outlet (or inlet) 17. When the blood is passed through the heat exchange part A and the gas exchange part B "in this order, the blood introduced into the blood inlet 12 flows through the bores in the hollow fibers 15 into the heat exchanger and takes place there exchanging heat with the heat exchange medium introduced into the heat exchange medium inlet 16 and passing the outside of the hollow fibers 15 used for the heat exchange, then the blood flows through the blood flow channel 13 and enters the gas exchange part B where the gas exchange takes place. Then, the temperature-controlled oxygenated blood exits the blood outlet 13.

In the blood oxygenator apparatus of Fig. 4, the gas exchange part B is constructed to be of the internal perfusion type in which the blood flows through the bores in the hollow fiber membrane 19 for gas exchange. An oxygen-containing gas is introduced into the gas exchange part B through the gas inlet 20, where it undergoes gas exchange with the blood flowing through the bores of the hollow fiber membrane 19 for the purpose of gas exchange through the medium of the hollow fiber membrane. The gas thus reduced in oxygen content and gas increased in carbon dioxide content is discharged at the gas outlet 21. In the blood oxygenator apparatus of Fig. 4, the blood may also first be subjected to gas exchange and then to heat exchange. This is achieved by introducing the blood through the blood outlet 18

and through the blood inlet 12.

In the blood oxygenator apparatus of the external perfusion type as shown in Fig. 5, the heat exchange part A differs from that shown in Fig. 4 only in that the blood does not flow through the bores in the hollow fibers 15 for the purpose of heat exchange, but instead flows on the outside of the hollow fibers. The heat exchange medium introduced through the heat exchange medium inlet 16 (or 17) flows through the heat exchange medium flow passage 22 (or 23) formed between the housing 11 'and the potting member 14' through the holes in the hollow fibers and then passes through the other heat exchange medium Fleece Passage 23 (or 22). Subsequently, the heat exchange medium is removed from the heat exchange medium outlet 17 (or 16).

In the heat exchange part A of the blood oxygenator device according to the invention, the hollow fibers for the heat exchange and the castings may have been produced from the same material as has already been mentioned in connection with the heat exchanger according to the invention. In addition, the heat exchange part A can be prepared in the same manner as already described in connection with the heat exchanger.

In the gas exchange part B of the blood oxygenator device according to the invention, all the different types can be used

used by blood oxygenators, such as the usual membrane-type blood oxygenators or the bubble-type blood oxygenators. However, membrane type blood oxygenators, and particularly those employing hollow fiber membranes, are preferred.

Since the blood oxygenator apparatus of the present invention has an integrally formed heat exchanger, there is no need for circuit tubes or similar connection means to connect the bkut oxygenator to the heat exchanger, and the construction and operation of the circuit are easy and the volume of blood needed in the initial phase of the operation is low , Further, the blood oxygenator device according to the invention has the advantages that the processing of the heat transfer tubes is easy because one does not use metal tubes, and that the blood cells in the blood remain almost undestroyed, and further that the device is small and light.

Hereinafter, the blood oxygenator device according to the invention will be described in more detail with the particularly preferred embodiment in which the gas exchange part is formed as an internal structure of an improved membrane type blood oxygenator and wherein both the gas exchange part and the heat exchange part are in a single housing.

FIG. 6 shows a cross section of such a blood oxygenator device, and FIG. 7 is a part of FIG.

excerpt of it. This blood oxygenator device has a blood inlet 31, a blood outlet 32, a gas inlet 33, a gas outlet 34, a heat exchange medium inlet 35, and a heat exchange medium outlet 36, and includes a gas exchange part B and a heat exchange part A inside a housing 37 enclosing the Shape of a box has one. The gas exchange part B includes compartments each containing a bundle of hollow fiber membranes 38 for use in gas exchange and serving for gas exchange with the blood, and the heat exchange part A comprises a compartment (or a heat exchange chamber) in which a bundle of Hollow fibers 3 9 is located for use for heat exchange, and serves the function of heat exchange with the blood, wherein both departments are connected directly without the aid of pipes or similar connecting devices.

Basically, the heat exchange part B comprises hollow fiber membranes 38 for use in gas exchange and castings (or barrier parts) 40. These parts serve to make the interior of the gas exchange part B in a contact chamber 41 through which blood flows a gas distribution passage 42 for introducing the oxygen-containing gas into the gas exchange part Holes of the hollow fiber membranes 38, and a gas collecting passage 43, for passing the gas to the gas outlet 34 to divide. The contact chamber 41 includes a number of orifices 44, which extend transversely to the blood flow, and the flow path of the blood in vertical

Direction to the hollow fiber membranes (hereinafter referred to as the direction of the thickness of the contact chamber) to narrow and through these chokes, the contact chamber 41 in a number of departments 45, containing the hollow fiber membranes 38, divided.

At the throttles 44, one or more struts 46 may be provided so as to extend in the direction of the contact chamber 41.

The hollow fiber membranes 38 extend substantially in a straight line within the compartments 45 and are secured with two opposing potting members 40 such that their respective ends are open to the gas distribution passage 42 and the gas collecting passage 43.

In the gas exchange part B of this blood oxygenator apparatus, an oxygen-containing gas is introduced into the gas distribution passage 4 2 through the gas inlet 33, and then flows through the bores of the hollow fiber membranes 38 located in the contact chamber 41, where it undergoes gas exchange with the blood the hollow fiber membranes. The thus reduced in oxygen content and increased in carbon dioxide gas is passed through the Gassammeipassage 43 and then discharged at the gas outlet 34. Of course, the oxygen-containing gas introduced through the gas inlet 33 may also be pure oxygen.

Furthermore, this is the human body withdrawn

Blood (i.e., venous blood) is introduced into the blood flow balancing chamber 4 7 through the blood inlet 31 and flows through the contact chamber 41, where the gas exchange by means of the hollow fiber membranes takes place with the oxygen-containing gas flowing through the bores of the hollow fiber membranes 38. In this way, venous blood is transferred into arterial blood, which is then passed through the heat exchange part A by means of the blood flow channel 48 which connects the gas exchange part B to the heat exchange part A.

In the embodiment shown in FIG. 6, the contact chamber is divided into three compartments 45 by means of the two throttles 44. However, there may be any number of divisions 45 provided that the number of compartments 4 5 is not less than two. Although a larger number is preferred; for convenience and ease of manufacture, it is desirable for the contact chamber to have two to six compartments.

The throttles 44 may have any cross-section provided that they narrow the blood flow channel in the direction of the thickness of the contact chamber. Throttles or baffles with a curved cross-section, as shown in FIG. 6, are preferred in order to prevent stagnation of the blood. The throttles provided in the contact chamber 41 serve not only to prevent channeling of blood vessels.

To avoid flow in the direction of the thickness, but also to the oxygen and carbon dioxide content of the blood in cross section perpendicular to the direction of the blood stream to make uniform and thereby cause a good gas exchange.

As shown in Fig. 6, the manner in which the blood flow channel is narrowed by the throttles 4 4 in the direction of the thickness of the contact chamber should preferably be such that adjacent restrictors 44 are alternatively attached to the upper and lower walls.

The dimensions of the contact chamber 41 in the blood oxygenator device according to the invention will be explained below. Preferably, the length a in each compartment 45, measured in the direction of the blood flow, should be greater than the maximum thickness h of the compartment. If the thickness h is greater than the length a, then the blood flow towards the thickness predominates so that stagnation of the blood may occur at the corners of the compartment (ie near the boundaries between the compartment and the constricted blood flow channels) and if there are air bubbles are trapped, these trapped air bubbles are difficult to remove. In order to achieve the effect of the throttles 44, the thickness of the blood flow channels narrowed by the throttles 44 should preferably be equal to or less than one half of the thickness h of the compartments.

The width 1 of the contact chamber 41 (i.e., the distance between the two encapsulants 40) should be suitably designed with respect to the flow rate of the blood and the thickness h of the compartments. In order to achieve the desired sheet-like flow of the blood in the contact chamber, the width 1 of the contact chamber should be something one to twenty times greater than the thickness h of the contact chamber. If the width 1 is less than the thickness h, then the surfaces of the castings have a marked effect on the bloodstream and occasionally give a bad work. If the width 1 is more than twenty times the thickness h, then it will be in some degree It is difficult to spread the blood evenly over the surface of all hollow fibers, thus avoiding channeling of the blood.

In the contact chamber, the hollow fibers are arranged nearly perpendicular to the direction of blood flow.

As used herein, the term "direction of blood flow" does not mean the direction of the blood flow actually given by passing the blood through the contact chamber, but the direction of the straight line connecting the blood inlet to the blood outlet. In order to avoid channeling of the blood, the hollow fibers must form an angle of at least 45 ° to the direction of the blood flow, wherein it is particularly preferred that the hollow fibers are arranged almost perpendicular to the direction of the blood stream. The reason is probably that if that

Blood flows over the hollow fibers, small turbulences of blood flow are formed around the hollow fibers. Furthermore, the large number of hollow fibers in the respective compartments is preferably introduced such that each subsequent fiber is parallel to the longitudinal axis of the hollow fiber bundle. But you can also arrange them so that the majority of the hollow fibers is bundled and that they are wound at an angle of up to 45 ° to the longitudinal axis of the bundle of hollow fibers.

The packing rate of the hollow fibers in the respective compartments is preferably 10 to 55%. The term "packing ratio" means the proportion of the Ge velvet cross-sectional area of the hollow fibers to the cross-sectional area of the compartment seen in a plane perpendicular to the direction of blood flow in the contact chamber. If the packing rate is less than 10%, blood is likely to channel and blood flow turbulence can hardly be formed. If the packing ratio is greater than 55%, the flow resistance of the blood is too high and hemolysis can be initiated. Although the degree of packing of the hollow fibers can vary in the individual compartments, but for the sake of handling the production, one uses the same packing ratio for all compartments.

The hollow fibers used for gas exchange in the blood oxygenator device may be any hollow fibers made from homogeneous or porous membrane materials

have been prepared, for example, celluloses, polyolefins, polysulfones, polyvinyl alcohol, silicone resins and PMMA. However, hollow fibers made of a porous polyolefin membrane are preferred because of their excellent durability and gas permeability. Most preferred are hollow fibers of a membrane in which fibrils are laid in layers between both surfaces and the nodes through which the respective ends of the fibrils are fixed, thereby forming micropores from the spaces between the fibrils and. are connected so that they extend from one surface to the other. Examples of such hollow fibers are polypropylene hollow fibers and polyethylene hollow fibers manufactured by Mitsubishi Rayon Co., Ltd. available under the trade names KPF and EHF.

Struts 46, which may be provided on the throttles 44, serve to create turbulence of the blood flow in the contact chamber and also to cause the hollow fibers in the compartments to be displaced towards the throttles by means of the blood flow, thereby increasing the flow rate high degree of packing of the hollow fibers would occur in these regions and then a hemolysis or the like would be initiated. According to a preferred embodiment of the invention, such struts 46 are provided.

0 For the sake of simplicity, the castings 4 0 can be produced in the same way as the so-called

Hollow fiber filtration modules using hollow fibers. This can be accomplished by selecting a potting material having good adhesive properties from polyurethane, unsaturated polyesters, epoxy resins, and the like, and then molding it integrally with the hollow fibers.

Further, in the heat exchange part A, a heat exchange medium 35, a heat exchange medium distribution passage 49, a hollow fiber bundle 39 for use as a heat exchanger, a heat exchange medium collection passage 50, and a heat exchange medium outlet 36 are provided. The hollow fiber bundle 39 used for heat exchange use, in which a heat exchange medium, such as warm water, flows through its bores, is nearly perpendicular to the direction of the blood flowing from the Blutfliesskanal 48 to the blood outlet 32. When the hollow fibers 39 are arranged in this manner, it is possible to reduce the heat transfer resistance of the laminar blood film and increase the heat exchange efficiency between the blood and the heat exchange medium, and thereby it becomes possible to form the heat exchange part A in a compact size.

In the embodiment shown in Figures 6 and 7, the heat exchange chamber 51 containing the bundle of hollow fibers 39 for use as a heat exchanger comprises only one compartment.

Similarly to the gas exchange part B, the heat exchange chamber may be divided into a plurality of

Be divided departments. Although this embodiment provides for blood to flow through the gas exchange part B and the heat exchange part A in this order, it is also possible to subject the blood to heat exchange in the heat exchange part A and then gas exchange in the gas exchange part B. Furthermore, the hollow fiber bundles for use, for heat exchange and those for use in gas exchange may be distributed in all desired portions of the contact chamber of the blood oxygenator apparatus of the present invention to subject the blood to gas exchange and heat exchange in any desired order.

This improved type of blood oxygenator apparatus having a heat exchanger not only has the aforementioned advantages of the exchanger of the present invention, but additionally exhibits the valuable effects of having a high oxygenation and carbon dioxide desorption rate per unit area of the hollow fiber membrane (even if the blood is low in blood) Pressure Leak passes through) achieved because only a small stagnation or channeling of the blood occurs and the turbulence of the blood stream are easily generated.

The invention is explained in more detail in the following examples

 30

example 1

A water-water heat exchange experiment was carried out using a heat exchanger as shown in FIG. The hollow fibers used in this heat exchange consisted of high-density polyethylene and had an inner diameter of 36 microns and a wall thickness of 20 microns. The effective heat exchange length f of the hollow fibers was 10 cm and their effective heat exchange area was 0.1 m ² and the packing ratio (ie the proportion of the total cross-sectional area of the hollow fibers to that of the housing as viewed in the cross section along the line XX 'in Fig. 2) 17%.

Water with- a temperature of 30 ⁰ C was introduced through the fluid inlet in amounts as shown in Table 1, while water was fed at a temperature of 4 0 ° C through the heat exchange chamber. Then, the temperature of the water flowing out of the fluid outlet was measured.

table

Water flow (l / min) Fluid temperature at the fluid outlet 1.0 2.0 37.2 ° C 36.4 ⁰ C

Of course, one can adjust the water temperature at the fluid outlet to any desired value by suitably selecting the inlet temperature and the flow rate of the water passing through the heat exchange chamber.

Example 2

A blood oxygenator having a structure according to that shown in Figs. 6 and 7 was constructed. The gas dispenser B consisted of three compartments with a thickness h of 4.0 cm, a length a of 4.0 cm and a width 1 of 13 cm, each compartment separated by two blood flow channels narrowed by throttling and one thickness e of 1 cm and a length of 0.5 cm. In each of these compartments, hollow fibers for gas exchange were packed to give a packing rate of 25%. The hollow fibers were hollow fibers made from a porous polypropylene menran (available from Mitsubishi Rayon Co., Ltd. under the trade name of KPF) and had a wall thickness of 22 μm, an inner diameter of 20 μm and a bubble point of 12.5 kg. cm ² . The total surface area of the membrane, calculated on the basis of the inside diameter, was 2.0 m ² . The heat exchange part A consisted of a heat exchange chamber having a thickness h 'of 4.0 cm, a length b of 3.0 cm and a

Width 1 of 13 cm, in which the same hollow fibers as in Example 1 were used, which were packed to give a packing of 25 ' (with a heat transfer area of 0.25 m ² , calculated on the basis of the inside diameter) Gas exchange part B and heat exchange part A were connected to each other through a blood flow channel having a thickness of 1 cm and a length of 1 cm.

By means of this blood oxygenator, a heat exchange test was performed on bovine blood previously set at 3 ° C. The bovine blood had a hematocrit of 35%, a pH of 7.3 and an oxygen partial pressure of 65 mmHg, a carbon dioxide partial pressure of 45 mmHg and a hemoglobin concentration of 12.5 g / dl.

The bovine blood was through the blood inlet. 31 introduced at different flow rates, while pure oxygen at a temperature of 30 ⁰ C was introduced through the gas inlet 33 at a flow rate of 10 l / min. Separately, warm water having a temperature door 36, 38 and 40 ⁰ C was introduced through the heat exchange medium inlet 35 and that with flow rates of 5, 7 and 9 l / min. Then the temperature of the blood leaving the blood outlet 32 was measured, 30

The results obtained with warm water of 4 0 ⁰ C results

are shown in FIG. Had this warm water a temperature of 36 or 38 ⁰ C, then the results obtained were substantially the same as shown in Fig. 8. From these results it can be seen that the temperature of the blood arising at the blood outlet can be adjusted to any desired value by varying the temperature and the flow rate of the heat exchange medium. In Fig. 8, the heat exchange coefficient is defined according to the following equation:

Heat exchange coefficient

.Auslasstemperatur. _Inlet temperature,

'the blood of the blood'

Inlet temperature. _. Outlet temperature.

  the warm water of the blood

Then, the same procedure was repeated, but the bovine blood and the oxygen were adjusted to 37 ⁰ C and the blood flow rate per unit area of the membrane (Q / S) was changed from 0 to 3 l / m ² -min. Then the oxygen partial pressure of the blood leaving the blood outlet was measured to determine the oxygenation rate (in ml / min-m ² ) of this blood oxygenator.

The results are shown in FIG.

Claims (7)

CLAIM THE INVENTION A heat exchanger of (1) a housing, (2) a hollow fiber bundle of an organic polymer, wherein the hollow fiber bundle is introduced and packed within the housing so that it is fluid-tight at both ends, (3) a heat exchange chamber on the outside of the hollow fibers and (4) a fluid inlet chamber and a fluid outlet chamber provided at the respective ends of the bundle of the hollow fibers so as to communicate with the bores of the hollow fibers. 2. Heat exchanger according to item 1, characterized in that the hollow fibers (1, 15, 39) have an inner diameter of 50 to 1000 μΐη and a wall thickness of 2 to 200 microns. 3. Heat exchanger according to item 1, characterized in that the hollow fibers (1, 15, 39) have an inner diameter of 150 to 500 microns and a wall thickness of 10 to 100 μΐη. 4. Blood oxygenator device with a heat exchange part for controlling the blood temperature and a gas exchange part for effecting the gas exchange of the blood, characterized in that (1) the heat exchange part (A) a fret-1 of hollow fibers (1, 15, 39) of an organic polymer as a heat exchange part, wherein the bundle is introduced and packed in the heat exchange part so as to be at both ends is fluid-tight, and (2) a fluid inlet chamber (5) and a Fluid outlet chamber (6), which at the respective ends of the hollow fiber bundle are provided so that they communicate with the holes in the hollow fibers. 5. Blutoxygenator device according to item 4, characterized in that the hollow fibers (1, 15, 39) have an inner diameter of 50 to 1000 μπι and a wall thickness of 2 to 200 μΐη. 6. blood oxygenator of the hollow fiber membrane type with a built-in heat exchanger, characterized by (1) a housing (2, 11, 11 ', 37) with a Blood inlet (12, 31), a blood outlet (18, 32), a gas inlet (20, 33), a gas outlet (21, 34), a heat exchange medium inlet (16, 35), and a heat exchange medium outlet (17, 36) and a contact chamber (41); wherein the contact chamber comprises blood flow channels (13, 48) narrowed by throttles (44) and a plurality of compartments separated from each other by the blood flow channels are separated; (2) a first bundle or bundles of hollow fibers (1, 15, 39) of a large number of hollow fibers for use for gas exchange with fixed ends; and (3) a second bundle or bundle of hollow fibers consisting of a large Number of hollow fibers for use in heat exchange with fixed ends, the first and the first. second hollow fiber bundles are placed in separate compartments so that they are in essence parallel to the throttles (44) and the respective ends of the first hollow fiber bundle with the gas inlet (20, 33) and the gas outlet (21, 34) and the respective ends of the second hollow fiber bundle with the heat exchange medium Inlet (16, 35) and the heat exchange medium outlet (17, 36) communicate. 7. Blood oxygenator according to item 6, labeled-5, characterized in that the hollow fibers for use in heat exchange have an inner diameter of 50 to 1000 μΐη and a wall thickness of 2 to 200 μπι. - For this 4 sheets drawings -