A fluid delivery injector comprises a syringe defining a barrel; a plunger and a hollow needle provided within the barrel adapted for linear movement parallel to a longitudinal axis with a distal tip of the needle contained within the syringe. A fluid retention reservoir is defined at least in the barrel and is in fluid communication with the needle when pressure is applied to the fluid in the reservoir and to the plunger for moving the needle out of the barrel. A spring may be provided for retracting the needle when pressure is released from the plunger.

A needle assembly is disclosed, which includes a needle protection member and a rotor. The rotor has a rotor body and a restriction portion. When the needle protection member in the initial state is displaced from the protection position to a use position and returns to a protection position, the restriction portion is displaced from the initial position to the lock position by the rotation of the rotor body with respect to the needle protection member. A needle hub has a displacement prevention portion that prevents the needle protection member from being displaced from the protection position to the use position again by contacting the restriction portion at the lock position.

Drug delivery devices for selecting and dispensing a number of doses of a medicament are provided. The drug delivery device includes a medicament reservoir attached to a housing, a drive mechanism including a plunger axially movable relative to the housing for dispensing doses of the medicament from the medicament reservoir, a dose selecting element releasably coupled to the drive mechanism and rotatable relative to the housing in a first direction for selecting a dose, a trigger axially movable relative to the housing for initiating dispensing of a dose selected by the dose selecting element, and a limiter selectively permitting and preventing axial movement of the trigger depending on the amount of the selected dose.

A low retraction activation force plunger sub-assembly for an automatic injector includes: a plunger outer having one or more engagement prongs, a plunger inner having a shoulder, and a plunger biasing member retained in a first energized state between said plunger outer and plunger inner when the engagement prongs of the plunger outer are releasably engaged with the shoulder of the plunger inner. An automatic injector includes a housing, an activation mechanism, an actuation mechanism, and a syringe cartridge having the plunger sub-assembly and a needle assembly, wherein the actuation mechanism includes comprises an actuation biasing member residing in an initial energized state substantially within an upper portion of an actuation pill. A method of assembling the automatic injector includes the steps of: assembling the plunger sub-assembly and inserting the plunger sub-assembly into the housing such that a proximal end of the plunger sub-assembly contacts the actuation pill.

Embodiments of a retractable syringe assembly are provided that include a single syringe barrel configuration and dual syringe barrel configuration. In one or more embodiments, the assemblies include a barrel having a dividing wall to divide the chamber to define a fluid chamber having a first cross-sectional width for retaining fluid and a needle chamber for housing a needle hub assembly. The assemblies include a projection extending radially outwardly from the plunger rod to interact with a ramped portion of the dividing wall to cause the needle cannula to retract and be housed within the needle chamber.

Embodiments of a retractable syringe assembly are provided that include a single syringe barrel configuration and dual syringe barrel configuration. In one or more embodiments, the assemblies include a barrel having a dividing wall to divide the chamber to define a fluid chamber having a first cross-sectional width for retaining fluid and a needle chamber for housing a needle hub assembly. The assemblies include a projection extending radially outwardly from the plunger rod to interact with a ramped portion of the dividing wall to cause the needle cannula to retract and be housed within the needle chamber.

Embodiments of a retractable syringe assembly are provided that include a single syringe barrel configuration and dual syringe barrel configuration. In one or more embodiments, the assemblies include a barrel having a dividing wall to divide the chamber to define a fluid chamber having a first cross-sectional width for retaining fluid and a needle chamber for housing a needle hub assembly. The assemblies include a projection extending radially outwardly from the plunger rod to interact with a ramped portion of the dividing wall to cause the needle cannula to retract and be housed within the needle chamber.

A catheter insertion system includes a housing extending along a longitudinal axis. A needle extends distally from a distal end of the housing. The needle has a longitudinal passage coaxially aligned with the housing. A catheter has a length and is sized and shaped to be advanced from a retracted position within the longitudinal passage of the needle to an extended position with at least a portion of the catheter length extending beyond a distal tip of the needle. The needle is typically configured to be retracted back into the housing after the catheter has been advanced thus providing an integrated catheter and catheter insertion apparatus. After needle retraction, the housing may be taped to the patient's skin while the needle remains protected within the housing. A luer on the catheter may then be connected to a fluid or other source in an otherwise conventional manner.