Method and device for fluid transfer in an infusion system

A method for fluid transfer in an infusion system, said method comprising:

• utilizing a fluid transfer device to inject a medical substance from a drug bottle containing a fixed dose of said medical substance into an infusion system via an injection port sealed by a flexible barrier member, said fluid transfer device comprising at least a first member, a hollow needle attached to said first member, and a second member telescopically and retractably displaceable in relation to said first member, said fluid transfer device further comprising a first end, and a second, opposite end having a flexible membrane;
• attaching said first end of said fluid transfer device to said drug bottle;
• releasably coupling said second end of said fluid transfer device to said injection port while pressing said flexible membrane against said flexible barrier member with a pressure sufficient for creating a double-membrane sealing by said flexible membrane and said flexible barrier member;
• creating a fluid passage from said first end of said infusion system by telescopically displacing said first end in a direction towards said second end and thereby allowing said hollow needle to penetrate said flexible membrane and said flexible barrier member while being surrounded by said double-membrane sealing formed by said flexible membrane and flexible barrier membrane;
• transferring said fixed dose from said drug bottle into said infusion system by means of creating and subsequently releasing a positive pressure inside said drug bottle;
• and
• displacing said first end away from said second end while said fluid transfer device is connected to said infusion system and said drug bottle.

A fluid transfer device for temporarily establishing fluid communication between a drug bottle and an infusion fluid container that is adapted for transferring a medical substance from the drug bottle to the infusion fluid container for mixture with infusion fluid container therein and the fluid transfer device is configured to prevent leakage of the medical substance into the ambient environment during both transfer of the medical substance into the infusion fluid container and after disconnect of the fluid transfer device from the infusion fluid container, said fluid transfer device comprising:

• a first end including a connecting portion for interconnection with a drug bottle containing a fixed dose of a medical substance;
• a second end opposite said first end and configured to be releasably coupled to an injection port of an infusion fluid container that is sealed by a pierceable flexible barrier, said second end of said transfer device having a flexible membrane located to be pressed against the flexible barrier of the injection port when coupled thereto;
• and
• a first member having a hollow needle attached thereto and said first member being telescopically associated with a second member, said first member and second member being displaceable relative to each other to and fro between two end positions, so that upon displacement of said first member in a first direction relative to said second member when said fluid transfer device is coupled to the injection port, said hollow needle pierces said flexible membrane and the flexible barrier thereby creating a fluid passage from said first end into the infusion fluid container with a double-membrane seal around said hollow needle, and upon displacement of said first member relative to said second member in a second direction opposite to the first direction, said hollow needle is withdrawn to a position within said flexible membrane while said fluid transfer device is connected to said infusion fluid container and said drug bottle, thereby enabling disconnection of the fluid transfer device from the infusion fluid container.