Pre-filled safety diluent injector

A medical device, comprising:

• a barrel having an open proximal end, a distal end and an opening through the barrel wall oriented perpendicularly to the longitudinal axis of the barrel;
• a needle having a first sharpened tip and being operable between an extended position in which the first sharpened tip projects forwardly from the barrel and a shielded position in which the first sharpened tip is shielded to prevent inadvertent contact with the first sharpened tip;
• a cartridge in fluid communication with the needle, comprising:
• a first chamber containing a first substance;
• a second chamber containing a second substance;
• a fluid flow controller connecting the first chamber and the second chamber;
• and
• a plunger slidably disposed within the cartridge;
• a biasing element imparting a force capable of displacing the needle relative to the barrel to shield the first sharpened tip;
• a needle retainer releasably retaining the needle in the extended position;
• and
• a locking clip detachably connected to the barrel;
• wherein axially advancing the plunger within the first chamber advances the first substance through the fluid flow controller and into the second chamber where said first substance combines with the second substance to form a medicinal mixture, and removal of the locking clip from the barrel permits further advancement of the plunger and cartridge relative to the barrel to expel the mixture from the second chamber, whereafter axially advancing the cartridge disengages the needle retainer to allow the biasing element to displace the needle relative to the barrel to shield the first sharpened tip.

A medical device, comprising:

• a barrel having an open proximal end and a distal end;
• a needle having a first sharpened tip and being operable between an extended position in which the first sharpened tip projects forwardly from the barrel and a shielded position in which the first sharpened tip is shielded to prevent inadvertent contact with the first sharpened tip;
• a cartridge in fluid communication with the needle, comprising:
• a first chamber containing a first substance;
• a second chamber containing a second substance;
• a fluid flow controller between the first chamber and the second chamber;
• and
• a biasing element imparting a force capable of displacing the needle relative to the barrel to shield the first sharpened tip;
• and
• a needle retainer releasably retaining the needle in the extended position;
• wherein the fluid flow controller is adapted to keep the first and second substances separate prior to use, and also adapted to allow mixing of the first and second substances prior to an injection,
• wherein after use the needle is disposed in the shielded position.

A method for injecting medicine, comprising the steps of:

• providing an injection device having a first chamber containing a first medicinal component, a second chamber containing a second medicinal component, and a needle;
• transferring the first medicinal component from the first chamber to the second chamber;
• mixing the first and second components to form a medicinal mixture;
• expelling the medicinal mixture from the chamber;
• and
• retracting the needle after expelling the medicinal fluid to shield the needle against contact.