Method of forming a connection between two sealed condiutsusing radiant energy

(54) (56) (57)

APPLICANT Baxter International Inc Deerfield Ill US

INVENTOR DB Granzow, GL Carter, DW Ammann, Arlington Heights, Hoffman Estates, Lindenhurst Ill

OMBUD AWAPATENT AB

NAME Coupling device for the end portion of a conduit or flexible tube and use of the device

CALLED PUBLICATIONS: - SUMMARY:

A coupling member for the end portion of a conduit or flexible tube (16) comprises a housing (20) made of a material having a first radiation energy absorption capability and defining a passage (21) which communicates with the interior of the housing and is connected to the housing. or may be connected to the conduit or flexible tube (16), further comprising a wall device (30) supported by the housing and which normally seals the interior (21) of the housing towards communication with the atmosphere; said wall device being made of a thermoplastic material having a second radiant energy absorptive capacity which is greater than said first absorptive capacity and which is fusible to form an opening through the wall device upon radiant energy supply.

ALLF 138 8 122 AA

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The present invention relates to a coupling device for the end portion of a conduit or flexible tube.

The need to produce a sterile, sealed connection between a pair of conduits is particularly present in the field of blood and blood component processing and in other fields where a sterile container connection is desirable.

In the area of ​​blood treatment, it may be desirable to use only half of one unit of blood in a bag or the like. When this is the case, the unused portion of the blood unit is usually discarded within 24 hours of providing access to the bag, even when efforts have been made to maintain sterility through the use of conventionally accepted aseptic methods for providing access to the blood bag. This is because only one or two airborne bacteria can multiply in the stored blood and cause a risk of sepsis if the bacteria are allowed to multiply for more than a few hours and blo20 d_et was then administered to a patient.

In order to eliminate the need to discard the remainder of a blood unit when only one portion of the unit is needed, or for many other reasons a sealed, sterile connection between various containers is desirable, considerable research has been conducted to develop aseptic fluid transfer systems. . For example, US Patent 4,022,256 discloses a sterile connection device in which a heat-fusible tube has an inner layer of plastic material which does not melt at the temperature utilized. An allegedly sterile connection is provided by means of a heat punch which presses the non-digestible layer through the melting outer layer of the tube to form a sterile bond between the two tubes, the molten layer of the tube forming a single perforated layer.

According to this US patent, a special heat punch is required to press the non-melting layer through the meltable layer of the conduits. In addition, in the embodiment shown in the patent, the fusible material is pressed against the heat punch. By adhesion between the fusible material and the heat punch upon removal of the punch after this pressing, the connection can be stained or at least considerably weakened.

According to the present invention, the use of a heat and compression punch is eliminated to provide a sterile connection between two conduits. Instead, radiant energy is utilized to selectively melt a portion of the conduit wall without any physical contact between a punch or the like and the melt portion. In addition, according to the invention, a mechanical connection device may be arranged between the two linkages. for atite rf &amp; rhiiifbaa rrme.canic α ^ ρχχνηΐrg ^ of .xlat molten, sterile junction area.

With the coupling device according to the invention, which. having the features of the characterizing part of claim 1, a connection, particularly a sterile connection, may be provided between sealed conduits. Each conduit is provided with a coupling device having a thermoplastic wall portion, which preferably has a melting temperature of at least 200 ° C and is opaque for the particular radiant energy to be utilized. This melting temperature, which may be a temperature range, can be determined, for example, by means of differential thermal analysis.

To make the sterile connection, the thermoplastic wall portions are brought into contact with each other surface to surface. The wall portions are subjected to a sufficient amount of radiation energy to melt the wall portions and to form an opening through the melted wall portions. Thereby, sealed connection is provided

460 616 between the wiring interior.

In the coupling device, the thermoplastic wall portion is preferably supported along its circumference by the sleeve of the device which can be rigid and typically forms the end of a conduit. The rest of the management can, if desired, be flexible. The rigid sleeve is made of a material which is not softened under the particular radiation conditions used. Instead, the radiant energy can pass through the transparent sleeve, which preferably encloses and protects the opaque wall portions, when brought together surface to surface, that it is primarily these opaque, facing wall portions that are heated to their melting point rather than the transparent sleeve. which supports and protects the opaque wall portions.

When the opaque wall portions melt, they preferably merge into a single sealed mass, and due to the melt a central opening is formed in the molten opaque thermoplastic wall portion. Any bacteria located on the outer surfaces of the opaque wall portions are trapped in the molten mass and are killed before being exposed to the melting temperature of the opaque wall portions, which are preferably of the order of 200-250 ° C.

Radiation energy can, as desired, be supplied to the system by means of visible, infrared, ultraviolet or radio frequency radiation energy. By opaque is meant that opaque wall portions can absorb a large percentage of the particular radiation energy to which they are exposed. By transparency is meant that a lower percentage of the radiation energy is absorbed. Focused, infrared radiation energy is particularly suitable.

If desired, lasers can also be used to provide radiant energy.

The opaque wall portions may be biased singly or biaxially or with radial stress patterns to facilitate formation of the central aperture at the joint.

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in ⁴ 'joining of the opaque wall portions. Non-prestressed wall portions can also be utilized, the central opening being formed by cohesion during wetting.

In addition to the use cited above to establish a connection between the interior of two conduits, a coupling device according to the invention is also well suited to seal the end of a conduit or flexible pipe and to open the sealed end by connecting it. use of radiation energy.

The invention will now be described in more detail with reference to the accompanying drawing. Fig. 1 shows the ends of a pair of conduits, the other ends of which may be connected to a pair of blood bags or the like, and each end of which is terminated by a coupling device according to the invention. Fig. 2 shows on a larger scale and partly in longitudinal section a coupling device according to the invention. Fig. 3 shows the two ends shown in Fig. 1, when joined together in such a way that the opaque wall portions abut against each other surface, and also schematically shows how the opaque wall portions are exposed to enough radiant energy to fuse together and form an opening. . Fig. 4 shows on a larger scale and in longitudinal section the device according to Fig. 3 before irradiation. Fig. 5 shows on a larger scale and in longitudinal section the device according to Fig. 3 after irradiation.

Two conduits 10, 12 each have a flexible portion 14, 16, one end of which may be connected to a regular blood bag 17, 19 or other container.

Sockets 18, 20 are made of train-resistant, high-melt plastic material · such as Lexan, a polycarbonate material. Each sleeve has a hollow, inner chamber 21 which communicates with the bores of the tubes 14, 16, a pin 22 and a slot 24. Both the pin 22 and the slot 24 are so asymmetrically arranged on the sleeve that each pin 22 passes through substantially permanently The snap-lock action can be fitted into a corresponding slot 24 in a similar sleeve. Each pin 22 can be held in place in slot 24 by means of ·

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460 616 of a hook 26.

Thus, a pair of sleeves 18, 20 in the joined state can only be severely separated again. Preferably, an enlarged portion 28 of each stud 22 is dimensioned to abut against the inner wall of the slot 24 of the second sleeve, thereby making it more difficult to separate the sleeves by reducing the ability of the stud 22 to bend backward.

Each sleeve 18,20 has an opaque wall portion 30 which may be made of a thermoplastic material having a melting temperature of preferably at least 200 ° C.

For example, polycarbonate materials such as Lexan or polysulfone materials such as Udel or Radel can be utilized. Polyethylene sulfone materials can also be utilized.

The thermoplastic, opaque wall portion 30 usually contains a filler, such as carbon black, to become opaque, although other desired fillers, such as iron oxide, manganese dioxide or the like, which absorb the type of radiant energy to be utilized can be used instead of carbon black.

The opaque thermoplastic wall portion 30 is shown as a slab, which is preferably thinner at its center portion 32 than at its peripheral portion. The disc 30 can be secured by ultrasonic welding or the like along its circumference to the sleeve in a recess 34 therein and is slightly bent outward to facilitate good pressure contact between pairs of opaque wall portions facing each other in the manner shown in Fig. 4. An annular groove 33 allows space for the plastic in the wall portion to float when the opaque disc is inserted into the transparent sleeve.

Figure 4 also shows how the pin 22 fits in the opposite slot 24 of the second sleeve so that a connection is made between the respective sleeves, the opaque wall portions being compressed and enclosed by the respective sleeve.

When the sleeves 18, 20 are joined together, they are irradiated with radiant energy of the type absorbed by the spe460

616 cial opaque wall portions used. In particular, infrared radiation is a preferred form of radiation energy. For example, Denrja can be achieved by means of two 150 W Sylvania lamps with an elliptical reflector (model DJL). This provides focused, infrared light which can be focused towards the center of the adjacent wall portions 30 in such a way that the wall portions are rapidly heated to substantially the melting point for a period of time of preferably 10-20 s, resulting in the wall portions 30 being fused together that the opening 36 through the wall portions 30 is formed by the tension ceases or simply as a result of cohesive forces.

Bacteria trapped on the wall portions are killed by heating the wall portions 30 to the melting temperature and are further intercepted when the molten material in the wall portions 30 becomes hard again. This results in a connection between the sterile flow channels 21, while still maintaining sterility in the channels.

The molten wall portions 30 are fused together to form a hermetic seal around the opening 36 to prevent rupture in the flow path's sterility. At the same time, the sealing line 38 between respective membrane wall portions is protected against mechanical failure by the substantially permanent connection between the respective sleeves 18, 20.

Alternatively, if it is desired to utilize radio frequency energy or the like as radiant energy, the opaque wall portions 30 may be made of plasticized polyvinyl chloride, while the remainder of the sleeves 13, 20 may be made of a plastics material which is relatively inert to radio frequency poly, e.g., polypropylene, (vinylidene chloride) or a similar material which is not substantially heated when exposed to radio frequency energy or other high frequency high frequency electric radiation fields.

Thus, according to the invention, a sterile connection between, for example, a full and an empty blood bag can be achieved

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460 6ΐ6 by simply connecting one conduit from each bag, each conduit of the invention having a sleeve 18, 20. The joined sleeves can be subjected to focused infrared radiation to melt the opaque wall portions and fuse them together and form an opening. through the parties. Thus, a sterile compound has been provided through which a portion of the blood in the full blood bag can be fed to the empty bag for use. Thereafter, the connection between the bags may be broken in the usual manner by sealing one or both of the flexible conduits 14, 16 extending from the blood bag to the sleeves 18, 20, in a Hematron heat sealing apparatus. Thereafter, the blood bags can be transported to the desired place of use or back for long term storage.

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