JPWO1989002282A1 - Medical device and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] This publication contains application data prior to electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Medical Device and Manufacturing Method Thereof Technical Field The present invention relates to a medical device used in an extracorporeal circulation circuit in which blood is extracted from the human body, circulated internally, and then returned to the body, and to a manufacturing method therefor. In particular, the present invention relates to a medical device having a blood-contacting portion made of a hydrophobic material and a manufacturing method therefor.

BACKGROUND ART Artificial lung circuit devices have traditionally been used as extracorporeal circulation circuits, substituting for cardiac and pulmonary functions during cardiac surgery, for example. As shown in Figure 5, an artificial lung circuit device 100 generally comprises an oxygenator 1, a heat exchanger 50, a blood reservoir 31, a blood filter 70, a blood filter, a blood circuit 90 connecting these components to the human body 94, and a pump.

In recent years, model oxygenators have become increasingly popular as artificial lungs. Model oxygenators perform gas exchange by passing blood across one side of a gas exchange membrane housed in a housing, and oxygen-containing gas across the other side. Hydrophobic membranes, such as hydrophobic porous membranes made of polypropylene or polyethylene, or diffusion membranes made of silicone rubber, are commonly used as gas exchange membranes.

During use, a priming operation is performed to clean the interior of the model oxygenator and remove any internal air, followed by the injection of blood. Complete removal of air during the priming operation can be difficult. In particular, in hollow-fiber oxygenators using hydrophobic porous hollow fibers as the gas exchange membrane, air can be drawn from the gas side to the fluid side, resulting in an air-blocking phenomenon in which gas remains trapped between the membranes on the fluid side. As a result, the hollow fiber membrane in the gas-exchange region is not in contact with the blood, resulting in ineffective utilization of the central window membrane and insufficient gas exchange capacity. Furthermore, blood filters, which remove foreign particles and air bubbles from the blood returning to the human body after gas exchange, also use hydrophobic membranes. Therefore, as with the model oxygenator described above, complete removal of air during the priming operation can be difficult. In particular, air can remain on the hydrophobic membrane surface, reducing the effective surface area of the hydrophobic membrane and increasing the pressure loss of the blood filter.

Furthermore, artificial oxygenators, heat exchangers, blood filters, and blood tubes used for communication with the human body are generally made of flexible synthetic resins such as polyvinyl chloride and silicone rubber. Priming, as described above, is performed on the entire tube, just as it is on artificial lungs and blood filters. Because blood tubes are made of the above-mentioned materials, their inner surfaces are also hydrophobic. Therefore, even after priming, it is difficult to remove the fine air bubbles that adhere to the inner surface. These bubbles gradually leak into the blood as it circulates, causing air bubbles to form.

Furthermore, many parts of the model oxygenator and blood filter, even outside the membrane, are made of hydrophobic resins. This is also true for other components in the cardiopulmonary bypass circuit, such as the blood reservoir and heat exchanger. For example, the housings of model oxygenators, blood filters, blood reservoirs, and heat exchangers are generally made of hydrophobic resins such as polycarbonate, polystyrene, MBS, and polypropylene. Therefore, they have many blood-contacting parts made of hydrophobic materials. As with the inner surface of the blood tube described above, even with priming, it is difficult to remove small air bubbles adhering to the inner surface of these blood-contacting parts, which can cause air bubbles to form during blood circulation.

The object of the present invention is to provide a medical device and a method for manufacturing the same that allows easy removal of air and minimizes the formation of air bubbles during the priming process that is performed before blood circulation.

DISCLOSURE OF THE INVENTION The present invention relates to a medical device having a blood-contacting portion made of a hydrophobic material, characterized in that a biosafe surfactant is attached to part or all of the blood-contacting portion.

The present invention also provides a method for manufacturing a medical device, which includes assembling a medical device having a blood-contacting portion made of a hydrophobic material, contacting the blood-contacting portion with a liquid containing a biologically safe surfactant, and then drying the liquid to adhere the surfactant to the surface of the blood-contacting portion.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of an embodiment in which the medical device of the present invention is applied to a membrane oxygenator C; Figure 2 is a partial cross-sectional view of an embodiment in which the medical device of the present invention is applied to a special-type artificial lung device equipped with a heat exchanger and a blood reservoir; Figure 3 is a partial cross-sectional view of an embodiment in which the medical device of the present invention is applied to a blood filter I; Figure 4 is a cross-sectional view of the filtering member portion of the blood filter of Figure 3; Figure 5 is a schematic diagram of an artificial heart-lung circuit device.

BEST MODE FOR CARRYING OUT THE INVENTION The medical device of the present invention has a blood-contacting portion made of a hydrophobic material, and further, a biologically safe surfactant is attached to part or all of this blood-contacting portion.

Medical devices include blood circuits used in extracorporeal blood circulation systems and blood treatment devices attached thereto. Specific examples include artificial lungs, blood filters, heat exchangers, blood reservoirs, and blood circuits used in cardiopulmonary bypass systems, as well as dialyzers, blood circuits, and adsorption-type blood purification devices used in dialysis systems.

An embodiment in which the medical device of the present invention shown in FIG. 1 is applied to a membrane oxygenator will now be described.

The membrane oxygenator 1 comprises a cylindrical housing 2, an assembly of gas exchange hollow fibers 1113 housed within the cylindrical housing 2, and partitions 4, 5 that fluid-tightly secure both ends of the hollow fiber membranes 3 to the housing 2. The interior of the cylindrical housing 2 is partitioned into a blood chamber 12 (a first fluid chamber) and a gas chamber (a second fluid chamber). The cylindrical housing 2 is provided with a blood inlet 6 (a first fluid inlet) that communicates with the blood chamber 12, and a blood outlet port (a first fluid outlet). Attached above the partition 4 at the end of the cylindrical housing 2 is a cylindrical gas inlet port 10 having a gas inlet 8 (a second fluid inlet) that communicates with the gas chamber (the internal space of the hollow fibers 13). Thus, a gas inlet chamber 13 is formed by the outer surface of the partition 4 and the inner surface of the gas inlet port 10. This gas inlet chamber 13 is connected to the gas chamber formed by the internal space of the hollow fiber membrane 3. Similarly, a cap-shaped gas outlet port 11 is attached below the partition wall 5. The gas outlet port 9, a second fluid outlet, is connected to the internal space of the hollow fiber membrane 3. Therefore, a gas outlet chamber 14 is formed by the outer surface of the partition wall 5 and the inner surface of the gas outlet port 11. Because this type of oxygenator, in which blood flows outside the hollow fiber membrane, has low pressure loss, there is no need to install a blood pump before the oxygenator in the circulation circuit. Blood can be sent to the oxygenator simply by draining blood from the body.

The hollow fiber membrane 3 is a porous membrane with an inner diameter of 100 to 1000 μm, a wall thickness of 5 to 200 μm, preferably 10 to 100 μm, a porosity of 20 to 80%, preferably 30 to 60%, and a pore diameter of 0.01 to 5 μm, preferably 0.01 to 1 μm. The material used for the porous membrane is a hydrophobic polymer material such as polypropylene, polyethylene, polysulfone, polyacrylonitrile, polytetrafluoroethylene, or cellulose acetate. Polyolefin resins are preferred, and polypropylene is particularly preferred. Polypropylene with micropores formed in the wall by stretching or solid-liquid phase separation is even more preferred.

Furthermore, the hollow fiber membrane 3 may not be a porous membrane, but may be a diffusion membrane made of a material with high oxygen and carbon dioxide permeability, such as silicone rubber.

The cylindrical housing 2 is formed from a hydrophobic synthetic resin such as polycarbonate, an acrylic-styrene copolymer, or an acrylic-butylene-styrene copolymer.

The housing 2 is preferably cylindrical and transparent, for example, so that the interior can be easily seen.

In this embodiment, a large number of porous hollow fiber membranes 3 (approximately 5.000 = 100,000) are housed in parallel in the axial direction within the housing 2. Furthermore, the hollow fiber membranes 3 are fixed in a liquid-tight state by partitions 4.5 with both ends of the hollow fibers 1130 open at both ends of the housing 20.

The partitions 9, 4, and 5 are formed from a filling agent such as polyurethane or silicone rubber. Therefore, the area between the partitions 4 and 5 within the housing 2 is divided into a gas chamber inside the hollow fiber membrane 3 and a blood chamber 12 outside the hollow fiber membrane 3.

A gas inlet port 10 having a gas inlet 8 and a gas outlet port 11 having a gas exhaust port 9 are attached liquid-tight to the housing 2. These ports are also made of the same hydrophobic synthetic resin as used for the housing. Attachment to the housing 2 is achieved by fusion bonding using ultrasonic waves, high frequency waves, induction heating, or the like, bonding with an adhesive, or mechanically fitting.

Alternatively, a ring (not shown) may be used for fastening. Therefore, the blood-contacting parts of this membrane oxygenator 1 (the inner surface of the pufferfish 2 and the outer surface of the hollow fiber membrane 3) are all made of hydrophobic materials.

Although the above description has been given using a hollow fiber oxygenator, the present invention is not limited to this, and the gas exchange membrane may be a flat membrane.

A surfactant that is safe for the human body is applied to the entire blood-contacting portion of this special oxygenator 1.

The surfactants used in this invention are most preferably nonionic surfactants, particularly polyether-type polymer surfactants. Polyether-type polymer surfactants are generally block polymerized propylene oxide and ethylene oxide, and have molecular weights ranging from 1,000 to several tens of thousands. They are available in Pluronic and Tetronic types, and are further classified by the number of functional groups, type of alkylene oxide, block order, etc.

Particularly preferred are Pluronic-type polymer surfactants, and the structure of Pluronic-type polymer surfactants is as follows:

HO(C,H,O), (CIH,O), (C*H40)cH. This surfactant is characterized by its high molecular weight, ranging from 1,000 to tens of thousands. By adjusting and combining the molecular weight of the hydrophobic group and the amount of ethylene oxide added, a wide range of surfactants are available, allowing for flexible changes in molecular weight, HLB (hydrophilic/lipophilic balance), and other properties. It also has low foaming properties, is stable against acids, alkalis, peroxides, and metal ions, and is used as a pharmaceutical agent to prevent hemolysis in extracorporeal circulation, making it highly safe for the body.

In the present invention, "adhering a surfactant" refers to the presence of a dried surfactant on the blood-contacting portion, particularly on the blood-contacting surface of the gas exchange membrane. While the surfactant is preferably attached to the entire blood-contacting portion, it may also be attached to only a portion of the blood-contacting portion. For example, it may be attached only to the outer surface of the hollow fibers 1113, only to the inner surface of the housing 2, or even only to the inner surface of the blood inlet or blood outlet of the housing 2. In this case, when the priming solution is introduced through the blood inlet or blood outlet, the surfactant dissolves in the priming solution and spreads throughout the entire blood-contacting portion of the oxygenator.

Furthermore, since the above-mentioned surfactant is attached to the blood-contacting portion of the oxygenator 1, the contact angle of the blood-contacting portion with respect to the liquid is reduced, and the oxygenator 1 exhibits good wettability. Therefore, even when a liquid is introduced for priming, fine bubbles do not adhere to the surface of the blood-contacting portion, and priming can be performed reliably.

Furthermore, even when a hollow fiber membrane is used as the gas exchange membrane, complete priming can be achieved without causing the air blocking phenomenon in which air partially remains.

Next, an embodiment in which the medical device of the present invention is applied to a blood reservoir and a heat exchanger will be described using an oxygenator equipped with a blood reservoir and a heat exchanger as shown in FIG.

The artificial lung device 30 consists of a blood reservoir 31, an artificial lung 1, and a heat exchanger 50.

The blood reservoir 31 is composed of a housing 39 that forms a blood inlet 32, a blood reservoir, and a blood outlet 33, and a lid 38 that is attached to the top of the housing 39 and has a drug solution inlet 35 provided at its top.

The hard components constituting the blood reservoir 31 are formed from hydrophobic synthetic resins such as hard polyvinyl chloride resin, styrene resin, and carbonate resin. The housing 39 is preferably transparent so that the stored blood can be easily seen. Alternatively, the blood reservoir may be a sealed, soft blood reservoir formed into a bag shape from a soft synthetic resin, such as soft polyvinyl chloride resin, soft polyethylene, or soft polypropylene.

The blood inlet 32 of the blood reservoir 31 communicates with the blood outlet lower port of the oxygenator 1. Furthermore, the blood reservoir 31 preferably has a blood inlet portion communicating with the blood inlet 32. The blood inlet portion forms a blood flow path through which blood flowing into the blood reservoir 31 from the blood inlet 32 enters the blood reservoir, and has a bottom surface that is higher than the blood reservoir and has almost no drop from the blood inlet 32. The bottom surface may be flat or semi-flat, but a flat bottom is preferable because it facilitates the installation of a defoaming member 41, which will be described later.

The blood inlet preferably has a defoaming member 41 disposed across the blood flow path. The defoaming member 41 defoams incoming blood containing air bubbles and sends bubble-free blood to the blood reservoir. This defoaming member 41 is typically made of a foam, which utilizes its hydrophobic properties to grow and remove air bubbles. A foam is a three-dimensional, mesh-like object. The defoaming member 411 is preferably positioned in close contact with the bottom and sides of the blood inlet of the blood reservoir 31 so that it comes into contact with all of the incoming blood (to prevent the formation of a blood flow path that does not contact the defoaming member).

The upper end of the defoaming member 41 does not necessarily need to be in close contact with the lid 38 of the blood reservoir 31, but it is preferable that it be in close contact to prevent movement of the defoaming member 41 and to prevent blood from leaking out from the upper end of the defoaming member 41. Furthermore, to prevent movement of the defoaming member 41, it is preferable to provide a locking portion 43 on the inner surface of the housing 39. The locking portions 43 are ribs formed on the inner surface of the housing 39, and a total of four locking portions 43 are provided, sandwiching the end of the defoaming member 41 between them. The shape of the ribs forming the locking portions 43 is preferably continuous and linear.

The foam used for the defoaming member 41 may be urethane foam, cellulose foam, nylon foam, or the like. The above-mentioned surfactant is applied to the inner surface of the housing 39, which is the blood-contacting portion of the blood reservoir 31. This prevents air bubbles from adhering to the inner surface of the housing during priming. Furthermore, it is preferable to apply a surfactant to the defoaming member 41 as well.

In the embodiment 22 shown in Figure 2, the oxygenator 1 is the same as that shown in Figure 1. The fluid-tight connection between the blood outlet port 32 of the oxygenator 1 and the blood inlet port 32 of the blood reservoir 31 is achieved, for example, by a fluid-tight fit, such as a threaded fit, a tapered fit, or a fit via an O-ring, or by ultrasonic or high-frequency bonding, or by bonding using an adhesive.

Meanwhile, a heat exchanger 50 is attached to the blood inlet of the oxygenator 1. The heat exchanger 50 includes a casing 54 and multiple heat exchange tubes 55 arranged parallel to each other and spaced apart along the length of the casing 54. Both ends of the heat exchange tubes 55 are fixed fluid-tight to the side wall of the casing 54 by partitions (not shown) with their respective openings left open. The side of the casing 54 is provided with a blood inlet port 57 that communicates with a space 56 formed by the partition, the inner wall of the casing 54, and the outer wall of the heat exchange tubes 55. This space 56 also communicates with the blood inlet of the oxygenator 1. Meanwhile, the internal space of the heat exchange tube 55, which is fluid-tightly partitioned from the space 56, is in communication with a heat exchange medium inlet port provided on the outside of one of the partition walls of the casing 54 and a heat exchange medium outlet port provided on the outside of the other partition wall. Therefore, in this heat exchanger 50, blood flows into the heat exchanger 50 through the blood inlet port 57 and flows around the outside of the heat exchange tube 55, while a heat exchange medium (e.g., hot or cold water) flows inside the heat exchange tube 55, heating or cooling the blood. Alternatively, a heat exchanger in which blood flows inside the heat exchange tube and a heat exchange medium flows outside the heat exchange tube may be used.

The above-mentioned surfactant is applied to the inner surface of the casing 54 and the outer surface of the heat exchanger 55, which are the blood-contacting parts of the heat exchanger 50. If the heat exchanger 55 is substantially hydrophilic, it is not necessary to apply a surfactant to the heat exchanger 55.

In this oxygenator, the heat exchanger 50 and the blood reservoir 30 are each provided with a measurement probe insertion port 59, 61.

In the present invention, the surfactant does not need to be uniformly attached to the blood-contacting portion; it is sufficient if it is simply attached. Furthermore, the present invention is not limited to cases in which the surfactant is attached to the blood-contacting portion of an oxygenator. For example, in an oxygenator with a heat exchanger, the surfactant may be attached only to the heat exchanger, or in an oxygenator with a blood reservoir, the surfactant may be attached only to the blood reservoir. Preferably, the surfactant is attached to the entire portion. Even if the surfactant is attached only to a portion of the blood-contacting portion, the inflow of priming solution will elute the surfactant downstream, and the circulation of the priming solution through the sieve will ultimately prevent air bubbles from adhering to the entire blood-contacting portion.

Next, an embodiment in which the medical device of the present invention is applied to a blood filter will be described with reference to Figures 3 and 4. The blood filter 70 is installed in the cardiopulmonary bypass circuit shown in Figure 5 and removes air bubbles and foreign matter from the blood flowing through the circuit.

As shown in Figures 3 and 4, the blood filter 70 comprises a cylindrical housing 72 made of a hydrophobic resin such as polycarbonate, polypropylene, polyethylene, styrene-butadiene (SB) resin, or methylene-butadiene-styrene (MBS) resin, and a filter member 79 housed within the housing 72 and interposed between a blood inlet lower 5 and a blood outlet lower 8. A lid 3 is fixed liquid-tight to the upper end of the housing 72, and has a communication port 83 to which an opening/closing means, such as a three-way stopcock, can be attached. The blood inlet lower 5 is attached tangentially to the cylindrical housing 72 to prevent the blood flow containing air bubbles from directly impinging on the filter member 79. This causes the blood to flow swirl into the housing 72.

As shown in FIG. 4, the filter member 79 is a screen mesh with a large opening of 20 to 50 μR, made of a hydrophobic synthetic resin such as polypropylene, polyethylene, or polyester.

The filter element 79 is sandwiched between a net 81.1 made of polypropylene, polyethylene, polyester, or the like, and then pleated to form a cylindrical shape. The upper part of the cylindrical filter element 79 is filled with synthetic fibers such as polyolefins such as polypropylene and polyethylene, ethylene vinyl acetate (EVA), polyurethane, styrene-butadiene-styrene (SBS) elastomers, and silicone rubber, and hardened to form a blocking portion 79a. The filter element 79 is housed in the housing 2 with the blocking portion 79a of the filter element 79 facing upward. The lower end of the filter element 79 is also made into a blocking portion 79b using the above-mentioned resin, and is tightly attached to the bottom surface of the housing 72. A cylindrical, bottomed shape-retaining member 77 is inserted into the center of the filtering member 79, and a conical sealing member 76 covers the closing portion 79a of the filtering member 79.

The blood filter 70 thus constructed is configured so that blood flowing tangentially into the cylindrical housing 72 through the blood inlet lower portion 5 generates a swirling flow within the housing 72. Small air bubbles entrained in this swirling flow of blood gather at the center of rotation due to the action of centrifugal force, thereby performing air bubble separation. Furthermore, the filter material 79 prevents the passage of large foreign matter.

The blood filter 70 has the above-mentioned surfactant attached to its blood-contacting surfaces (the inner surface of the housing 72 and the surface of the filtering member 79). This reduces the contact angle of the blood-contacting surfaces with the liquid, providing good wettability. Therefore, even when a liquid is introduced for priming, fine air bubbles do not adhere to the surface of the blood-contacting surfaces, ensuring reliable priming. In particular, if a surfactant is attached to the surface of the filtering member (either the inner surface or the outer surface, or both), air does not remain partially on the filtering member surface, preventing a reduction in the effective filtering member surface area and an increase in power loss due to residual air. Primarily, priming of the blood filter 70 is performed by opening the communication port 83 and introducing liquid through the blood outlet lower 8 at the bottom of the housing 72, which pushes and removes the air inside the housing 72. Therefore, it is preferable to also attach a surfactant to the inner surface of the filtering member 79.

Next, a method for producing the medical device of the present invention will be described.

The method for manufacturing a medical device of the present invention involves assembling a medical device having a blood-contacting portion made of a hydrophobic material, contacting the blood-contacting portion with a liquid containing a biologically safe surfactant, and then drying the liquid to adhere the surfactant to the blood-contacting portion.

The medical device may be the above-mentioned blood circuit, artificial lung, etc. The surfactant may also be the same as above.

Possible methods for contacting the blood-contacting portion of a medical device with a surfactant-containing liquid include filling the blood-contacting portion of the medical device with the surfactant-containing liquid, or atomizing the surfactant-containing liquid and introducing it together with gas. Preferably, the surfactant-containing liquid is filled into the blood-contacting portion while sealing each end of the medical device to prevent leakage of the liquid to the outside.

When a liquid (solution or dispersion) containing the above-mentioned polyether-type polymer surfactant is used as the surfactant, it is preferable to use a 0.001 to 10% solution, particularly a 0.002 to 2.0% solution of the surfactant. The solvent is preferably an aqueous liquid, particularly water, and may also be water to which dimethyl alcohol has been added.

In an oxygenator, the surfactant can be attached to the blood-contacting portion by, for example, contacting the blood-contacting portion with a surfactant-containing liquid and then drying, or by blowing surfactant powder or surfactant-containing liquid into the blood-contacting portion together with air to attach the surfactant to the blood-contacting portion. In this way, the present invention can produce a medical device in which a surfactant is attached to the blood-contacting portion of the medical device after drying.

When the medical device is an oxygenator as described above, a leak test is typically performed after assembly of the oxygenator and before sterilization to check for pinholes in porous membranes, and for leaks at the attachment point between the gas exchange membrane and the housing (the partition). This test involves filling the blood chamber of the oxygenator with water and pressurizing it to check for leaks. If the surfactant-containing liquid contact step in the manufacturing method of the medical device of the present invention involves filling the liquid, the oxygenator leak test can be performed simultaneously. In this case, the manufacturing method of the oxygenator includes assembling a membrane oxygenator 1, in which the housing 2 is partitioned into a blood chamber and a gas chamber by a hydrophobic porous membrane 3 housed within the housing 2, filling the blood chamber with a surfactant-containing liquid, and then pressurizing the blood chamber or the gas chamber, and then removing the liquid and drying the liquid.

Furthermore, during leak testing, if the membrane has pinholes, water will leak more easily through those pinholes, increasing the sensitivity of the pinhole test. This effect is particularly pronounced when the contact angle with the membrane is 90° or less. A contact angle of 90° or less means that the membrane surface is more stable in contact with water than with air, and the only thing hindering wetting is the surface tension of the liquid. This surface tension facilitates wetting from a wide area to a narrow area, ensuring complete priming during use. It also prevents wetting from a narrow area to a wide area, preventing leakage through the pores of the porous hollow fiber (3). Pinholes are considered somewhere in between.

In principle, even if a porous membrane is used, there will be no leakage if the contact angle with the membrane is greater than Oe'. However, since the shape of the pores is uncertain, a contact angle of 45° or greater is desirable.

After the leak test is completed, the liquid is removed and the product is further dried, preferably by blowing in warm air.

Alternatively, natural drying may be used.

The above explanation was given using a membrane oxygenator, but the same can be applied to heat exchangers, blood filters, blood circuits, etc.

Next, the present invention will be described in detail.

[Example 1] Approximately 35,000 randomly selected porous polypyrylene fibers (inner diameter 200 μm, wall thickness 50 μm, average pore size 700 μm, porosity 40%) were bundled together to create a hollow fiber bundle. The bundle was then housed in a housing shaped as shown in Figure 1, and both ends of the hollow fiber bundle were secured to both ends of the housing by stretch-injecting polyurethane through the blood inlet and blood outlet of the housing, creating a hollow fiber membrane oxygenator (effective membrane area 2,711 inches) as shown in Figure 1.

A 0.1% aqueous solution of a polyether-type polymer surfactant (product name: Bluronic F68, manufactured by Wyandbutt, USA; structural formula: 8%) was then filled into the blood-contacting portion (blood side), pressurized at 1 atmosphere for 5 minutes, and a leak test was performed. The liquid was then drained, and air was blown in at 45°C and 50 e/sin per minute for approximately 180 minutes to dry the oxygenator, creating an oxygenator with the surfactant adhered to the entire blood-contacting portion.

Furthermore, weight measurements were carried out before and after the surfactant attachment treatment, and it was found that approximately 501g of surfactant had been attached.

Comparative Example 1 A hollow fiber artificial lung was prepared in the same manner as in Example 1, except that no surfactant treatment was performed. 7:c [Experiment 1] The following experiment was conducted using the artificial lungs of Example 1 and Comparative Example 1. The experimental circuit consisted of a blood reservoir positioned above the oxygenator, connected to the oxygenator's blood inlet, and a short tube attached to the oxygenator's blood outlet, with a blood collection container at its end. Therefore, in this experimental circuit, the oxygenator was the only source of pressure loss, and there were no sources of pressure loss downstream of the oxygenator.

The head between the blood reservoir and the oxygenator was set at a position where the blood flow rate was 4 (/g + in). The blood used was ACD with hemoglobin 129/dQ and oxygen saturation of 50% and heparinized blood.

Under the above conditions, the pressure loss and oxygen saturation were measured when blood was flowed into the oxygenators of Example 1 and Comparative Example 1. Furthermore, the pressure loss and oxygen saturation were measured after impacting the housing (by tapping it several times with forceps) while blood was flowing through the oxygenators of Example 1 and Comparative Example 10. The results are shown in Table 1.

[Example 2] The housing body and lid, shaped as shown in Figure 3, were made of polycarbonate. The volume was approximately 200 cubic meters. The filter element was a 40-micron-diameter Bollinister Mesh filter sandwiched between two polyester netting layers, one above the other, and then folded into pleats as shown in Figure 4. The surface area of the filter element was approximately 700 cubic meters.

The upper and lower ends of the filtering element were then sealed with polyurethane. A tapered cylindrical body with a disk-shaped flange at its tip and a closed lower end was inserted above the filtering element, and a conical sealing member was then affixed to the top of the cylindrical body. The lower end of the filtering element was then affixed to the lower end of the inner surface of the housing with polyurethane. The housing body and lid were then affixed to create the blood filter shown in Figure 3.

A 0.01% aqueous solution of a polyether-type polymer surfactant (Brulonic F68, manufactured by Wyandotte, USA, structural formula: ) was then introduced into the blood filter through the blood inlet at the bottom of the housing, filling the entire interior of the blood filter. The liquid was then drained, and air was pumped through the filter at 45°C and 50 psi/min for 60 minutes to dry the filter, creating a blood filter with the surfactant adhered to the entire blood-contact area.

Example 3 A blood filter was prepared in the same manner as in Example 2, except that a surfactant aqueous solution with a concentration of 0.015% was used.

[Example 4] A blood filter was prepared in the same manner as in Example 2, except that a surfactant aqueous solution with a concentration of 0.12% was used.

[Comparative Example 2] A blood filter was prepared in the same manner as in Example 2, except that no surfactant was applied.

Experiment 2: The following experiment was conducted using the blood filters of Examples 2, 3, and 4 and Comparative Example 2. With the blood inlet of the blood filter sealed and the communication port open, water was injected through the blood outlet. The injection rate was 2.0 o/c/w. The time from the start of injection until the water exited the filter element was measured. The results are shown in Table 2.

INDUSTRIAL APPLICABILITY The medical device of the present invention has a blood-contacting portion made of a hydrophobic material, and a biosafe surfactant is applied to part or all of the blood-contacting portion. This reduces the contact angle of the blood-contacting portion with the liquid, providing good wettability. When a liquid is introduced for priming, no fine bubbles adhere to the surface of the blood-contacting portion, ensuring reliable priming.

Furthermore, the method for manufacturing a medical device of the present invention involves assembling a medical device having a blood-contacting portion made of a hydrophobic material, contacting the blood-contacting portion with a liquid containing a biologically safe surfactant, and then drying the liquid to adhere the surfactant to the surface of the blood-contacting portion. This allows the surfactant to be reliably and easily adhered to the blood-contacting portion made of a hydrophobic material.

Claims (14)

[Claims] 1. A medical device having a blood-contacting portion made of a hydrophobic material, characterized in that a biologically safe surfactant is attached to part or all of the blood-contacting portion. 2. The medical device according to claim 1, wherein the medical device is a membrane oxygenator using a hydrophobic membrane as a gas exchange membrane, and the surfactant is attached to part or all of the blood-contacting portion inside the membrane oxygenator. 3. The medical device according to claim 1, wherein the medical device is a blood filter using a hydrophobic membrane, and the surfactant is attached to a part or all of the blood-contacting portion inside the blood filter. 4. The medical device according to claim 1, wherein the surfactant is a nonionic surfactant. 5. The medical device according to claim 1, wherein the surfactant is a polyether-type polymer surfactant. 6. The medical device according to claim 2, wherein the gas exchange membrane is a porous membrane. 7. The medical device according to claim 2, wherein the gas exchange membrane is a porous hollow fiber membrane. 8. The medical device according to claim 2, wherein the membrane oxygenator comprises a housing having a blood inlet and a blood outlet, a hollow fiber membrane bundle consisting of a large number of gas exchange hollow fiber membranes contained within the housing, a pair of partitions supporting both ends of the hollow fiber membrane bundle in a liquid-tight manner in the housing, a blood chamber formed by the partitions, the inner surface of the housing, and the outer surface of the hollow fiber membranes, and a gas chamber formed within the hollow fiber membranes, and further comprises a gas flow path formation provided on the outside of at least one of the partitions and having a gas inlet communicating with the gas chamber. 9. A method for manufacturing a medical device, comprising assembling a medical device having a blood-contacting portion made of a hydrophobic material, contacting the blood-contacting portion with a liquid containing a biologically safe surfactant, and then drying the liquid to adhere the surfactant to the surface of the blood-contacting portion. 10. The method for manufacturing a medical device according to claim 9, wherein the medical device is a membrane oxygenator whose housing is partitioned into a blood chamber and a gas chamber by a hydrophobic gas exchange membrane contained within the housing, and after assembling the membrane oxygenator, the blood chamber is filled with a solution containing a surfactant, and the blood chamber side is pressurized or the gas chamber side is negatively pressurized, after which the solution is removed and the device is dried. 11. The method for manufacturing a medical device according to claim 10, wherein the gas exchange membrane is a porous membrane. 12. The method for manufacturing a medical device according to claim 10, wherein the membrane oxygenator comprises a housing, a hollow fiber membrane bundle consisting of multiple gas exchange hollow fiber membranes housed within the housing, a pair of partition walls supporting both ends of the hollow fiber membrane bundle in a liquid-tight manner within the housing, a blood chamber formed by the partition walls, the inner surface of the housing, and the outer surface of the hollow fiber membranes, and a gas chamber formed within the hollow fiber membranes, and further comprises a gas flow channel forming member provided on the outside of at least one of the partition walls and having an inlet communicating with the gas chamber. 13. The method for manufacturing a medical device according to claim 9, wherein the surfactant is a nonionic surfactant. 14. The method for manufacturing a medical device according to claim 9, wherein the surfactant is a polyether-type polymer surfactant.