JPH0446590B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for high-pressure steam sterilization of a body fluid treatment device. [Prior art and its problems] Body fluid processing devices such as artificial kidneys, plasma separation processing devices, artificial lungs, and artificial livers house a large number of hollow fiber membranes in a casing, and both ends of the hollow fiber membranes are coated with urethane. It is fixed with a fixing member such as, and has a structure in which bodily fluid inlets and outlets are provided at the upper and lower parts of the casing. Conventionally, when sterilizing such a body fluid treatment device, the casing is filled with physiological saline, distilled water, etc. that are harmless to living organisms, and the openings such as the body fluid inlet/outlet and the dialysate inlet/outlet are tightly plugged, and then, A common method is high-pressure steam sterilization. In such a method, the filling liquid thermally expands during sterilization and damages the casing, so a buffer member is required to release the filling liquid. Conventionally, this buffer member has been used to absorb internal pressure by sealing the opening with a rubber stopper (Japanese Patent Publication No. 55-36340), or by connecting a buffer bag to a sealed cap of the opening to absorb the expanded fluid. There is a known method (Japanese Unexamined Patent Application Publication No. 103297/1983) for transferring the liquid to this buffer bag. However, in the former method of sealing the rubber stopper, since the device is sterilized in a closed system, there is a problem in that the air inside the device does not escape and remains as it is. The latter method of connecting a buffer bag has the advantage that the air inside the device can escape into this bag, but there are also issues with the heat resistance of the sealed cap, the adhesion with the mouth of the device, and the sealing of the buffer bag with the bag after sterilization. Sufficient consideration has not been given to the sealing performance when removing the cap by fusing the connecting portion. The present invention has been proposed to solve this problem, and uses a material that has excellent heat resistance and weather resistance and is easy to remove from the mouth as a sealing member for sealing the mouth of a body fluid treatment device. The purpose of this is to improve the sealing performance when the connection part with the buffer bag is fused and cut. [Means for Solving the Problems] For the above purpose, the present invention includes filling a body fluid treatment device with a filling liquid, sealing the mouth of the device, and connecting a pressure buffer bag to the sealed mouth. In the method in which high-pressure steam sterilization is performed in a state in which the filling liquid is heated and the thermal expansion of the filling liquid is absorbed by the pressure buffer bag, the mouth of the body fluid treatment device is made of polycarbonate resin, and the mouth is made of styrene-ethylene-butylene. - After sealing with a sealing member made of a styrene copolymer resin material and performing high-pressure steam sterilization with the mouth sealing member and the pressure buffer bag connected, the pressure buffer bag and the mouth sealing member are subjected to high-pressure steam sterilization. This is characterized in that the joints are fused and cut using an ultrasonic welder. Generally, when the mouth of a body fluid treatment device is made of polycarbonate, the thermoplastic elastomer connected to the mouth includes polyvinyl chloride elastomer, styrene elastomer, polyester elastomer, polyurethane elastomer,
Possible materials include ethylene-propylene rubber. However, when polyvinyl chloride-based elastomers and polyurethane-based elastomers are sterilized with high-pressure steam, they adhere closely to polycarbonate and cannot be removed during use. On the other hand, styrene-based elastomers, polyester-based elastomers, and ethylene-propylene rubber elastomers are connected to polycarbonate and do not adhere tightly even when subjected to high-pressure steam sterilization. By the way, when high-pressure steam sterilization is performed with the mouth sealing member of the body fluid treatment device and the pressure buffer bag connected, the filling liquid in the body fluid treatment device will enter the connection portion. After sterilizing, welding and cutting this connection, heat sealing, high frequency welding,
There are ultrasonic welders, but considering the presence of filling liquid in the connection, ultrasonic welders have excellent sealing properties. However, the above-mentioned polyester elastomer and ethylene-propylene rubber elastomer have unstable sealability with an ultrasonic welder, and there is a risk of liquid leakage. Therefore, in the present invention, when the mouth component of the body fluid treatment device is made of polycarbonate, a styrene-based elastomer is selected as the mouth sealing member,
Among these, we selected a styrene-ethylene-butylene-styrene copolymer resin material that has excellent heat resistance under high-pressure steam sterilization conditions, excellent weather resistance, etc., and is also advantageous in terms of moldability and cost. It is. The body fluid treatment device in the present invention includes an artificial kidney,
These include plasma separation processing devices, artificial lungs, artificial livers, etc., and the mouths of these devices are, for example, fluid inlets and outlets leading to the inside of the device, such as blood inlets and outlets, dialysate inlets and outlets, and the like. In addition, the pressure buffer bag in the present invention is a bag-shaped, balloon-shaped, tube-shaped, or other shape that can store liquid, and its material is polyvinyl chloride, polypropylene, natural rubber, synthetic rubber, etc. Any material is acceptable as long as it is non-toxic and can withstand high-pressure steam sterilization. [Example] FIG. 1 shows an example in which the present invention is applied to high-pressure steam sterilization of a hollow fiber artificial kidney. That is, for example, a large number of cellulose-based hollow fiber membranes are housed in the casing 1 (not shown).
A blood inlet part 2 is provided at one end of the casing 1, and a blood outlet part 3 is provided at the other end with a fixing ring 4, respectively.
It is attached by 5. Further, a dialysate inlet portion 6 is formed on the upper side of the casing 1, and a dialysate outlet portion 7 is formed on the lower side. In this embodiment, the casing 1, blood inlet/outlet portions 2, 3, and fixing rings 4, 5 are made of polycarbonate material. After assembly, this artificial kidney is filled with a filling liquid such as physiological saline, and the blood inlet/outlet portions 2, 3 and dialysate inlet/outlet portions 6, 7 are closed with sealing plugs 8, 9.
and 10, 11 are sealed. This sealing plug 8
-11 are composed of styrene-ethylene-butylene-styrene copolymer. On the other hand, 12 is a pressure buffer bag made of polyvinyl chloride, and a communication tube 13 made of polyvinyl chloride is connected to this pressure buffer bag 12, and the connection tube 13 is connected to one of the sealing plugs, for example. It is connected to the seal plug 9 of the blood outlet section 3. In this embodiment, as shown in FIG.
A tube insertion port 9a is formed in the tube insertion port 9a.
The distal end of the communication tube 13 is inserted into and fixed.
This fixing method may be any method as long as it does not come off during sterilization, and the material of the communication tube 13 may be any material as long as it can withstand the conditions of high-pressure steam sterilization. The communication tube 13 may be connected after the sealing stopper 9 is placed on the blood outlet portion 3, but the sealing stopper 9 may be connected to the communication tube 13 in advance. Note that the pressure buffer bag 12 is filled with a predetermined amount of physiological saline in advance to prevent air within the buffer bag 12 from moving into the interior of the artificial kidney. In the present invention, with the pressure buffer bag 12 connected to the sealing stopper 9, high-pressure steam sterilization (for example, 120° C., 20 minutes) according to the Japanese Pharmacopoeia is performed. At that time, when the filling liquid inside the artificial kidney expands thermally, the blood outlet part 3
From there, it passes through the communication tube 13 to the pressure buffer bag 12. After completing this high-pressure steam sterilization treatment, it is left to cool to room temperature. Next, the pressure buffer bag is separated by sealing the cut position 14 indicated by the dotted line in FIG. 2 using an ultrasonic welder, for example. Experimental Example 1 A brat port (blood inlet/outlet) molded from polycarbonate resin was commercialized and its function as a sealing stopper under high-pressure steam sterilization (121°C, 20 minutes) was investigated. The results are shown in the table below.

【table】

[Table] From the above table, it can be seen that the styrene elastomer does not adhere to the polycarbonate resin and has good removability. Experimental Example 2 A sealing property test of the styrene-ethylene-butylene-styrene copolymer after high-pressure steam sterilization was conducted under the conditions shown in the table below.

[Table] As shown in the table above, since the seal part contains a filling liquid, it is not possible to seal it consistently with heat sealing.
With a high-frequency welder, even if the output was increased, sufficient welding could not be achieved. Experimental Example 3 A hollow fiber artificial kidney having a blood port (blood inlet and outlet) molded from polycarbonate resin was filled with distilled water, and the port was sealed with a sealing plug made of the following material (the shape is the same as that shown in Figure 2). ) sealed. A bag made of vinyl chloride was connected to this sealing stopper, and after high-pressure steam sterilization was performed in the same manner as in Experimental Example 1, the connection portion of the sealing stopper was sealed with an ultrasonic welder and cut. In order to examine this sealing condition, an internal pressure of 1.0 Kg/cm ² was applied to check for leaks. A: Styrene-ethylene-butylene-styrene copolymer B: Ethylene-propylene resin C: Polyester resin

[Table] From this Experimental Examples 2 and 3, styrene-ethylene-
It can be seen that the butylene-styrene copolymer has excellent sealability with an ultrasonic welder compared to other resin materials. [Effects of the Invention] According to the present invention described above, when the mouth of the body fluid treatment device is made of polycarbonate resin, the mouth is sealed with a sealing member, and a pressure buffer bag is connected to this sealing member. When high-pressure steam sterilization is performed in this state, the sealing member does not come into close contact with the mouth of the body fluid treatment device, and can be easily removed during use. Also.
After sterilization, even if the filling liquid is present at the connection between the pressure buffer bag and the mouth sealing member, that part can be sealed well and cut, and sterility can be maintained. Furthermore, the mouth sealing member of the present invention has excellent heat resistance, does not deform even under high-pressure steam sterilization conditions, maintains sealing performance, and has excellent weather resistance, so it can be used over time. There is little deterioration and the sealing performance is maintained for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram for explaining an embodiment of the present invention, and FIG. 2 is an enlarged view of section A in FIG. In the figure, 1 is a casing, 2 is a blood inlet, 3 is a blood outlet, 6 is a dialysate inlet, 7 is a dialysate outlet, 8 to 11 are sealing plugs, 12 is a pressure buffer bag, 13
is a communication tube.

Claims (1)

[Scope of Claims] 1. Filling the body fluid treatment device with a filling liquid, sealing the mouth of the device, and performing high-pressure steam sterilization with a pressure buffer bag connected to the sealed mouth; In the method of absorbing the thermal expansion of the liquid with the pressure buffer bag, the mouth of the body fluid treatment device is made of polycarbonate resin, and the mouth is made of a resin material of styrene-ethylene-butylene-styrene copolymer. After performing high-pressure steam sterilization with the mouth sealing member and the pressure buffer bag connected, the connection portion between the pressure buffer bag and the mouth sealing member is fused by an ultrasonic welder. A method for high-pressure steam sterilization of a body fluid treatment device, characterized by: