Abstract: The present invention relates to a single-use syringe comprising a barrel (10) having an internal surface defining a chamber for retaining a fluid, a plunger (1) formed by an elongated body including a plurality of longitudinal fins (2) and optionally a piston (3) connected to the end of the plunger close to the needle, the external surface of the piston or of the end of the plunger in the case of not including a piston being in leak-tight connection with the internal surface of the barrel, where the barrel has a general external shape of a cylinder of revolution with a constant radius circular base and a variable internal shape, forming the wall of the barrel with variable thickness, generating a chamber inside which a plunger incorporating a plurality of fins (2) slides; each of the longitudinal fins (2) of the plunger has a constant height along its entire length but different from that of at least one of the other fins, which height is suitable in each fin so that the plunger (1) can be inserted tightly w

Abstract: The present invention relates to a single-use syringe comprising a barrel (10) having an internal surface defining a chamber for retaining a fluid, a plunger (1) formed by an elongated body including a plurality of longitudinal fins (2) and optionally a piston (3) connected to the end of the plunger close to the needle, the external surface of the piston or of the end of the plunger in the case of not including a piston being in leak-tight connection with the internal surface of the barrel, where the barrel has a general external shape of a cylinder of revolution with a constant radius circular base and a variable internal shape, forming the wall of the barrel with variable thickness, generating a chamber inside which a plunger incorporating a plurality of fins (2) slides; each of the longitudinal fins (2) of the plunger has a constant height along its entire length but different from that of at least one of the other fins, which height is suitable in each fin so that the plunger (1) can be inserted tightly w

Abstract: Self-disabling or self-locking single-use syringe of the passive type, i.e., one that is self-locked after first use of the syringe, in such a way that any attempted reuse is prevented, and is characterised in that it comprises at least two rings provided on the internal face of the barrel and having the general shape of a circular crown with a variable internal radius, and in that each of the longitudinal fins of the piston has a height which is different from that of at least one of the other fins, in such a way that the plunger can be inserted tightly through the space defined by the variable internal radius of the barrel rings. In this way resistance to the passage of the piston is minimised, thereby reducing the risk of causing bruises, and with a manufacturing cost substantially similar to that of conventional syringes.

Abstract: Self-disabling or self-locking single-use syringe of the passive type, i.e., one that is self-locked after first use of the syringe, in such a way that any attempted reuse is prevented, and is characterised in that it comprises at least two rings provided on the internal face of the barrel and having the general shape of a circular crown with a variable internal radius, and in that each of the longitudinal fins of the piston has a height which is different from that of at least one of the other fins, in such a way that the plunger can be inserted tightly through the space defined by the variable internal radius of the barrel rings. In this way resistance to the passage of the piston is minimised, thereby reducing the risk of causing bruises, and with a manufacturing cost substantially similar to that of conventional syringes.