Patent ID: 9604015
Date: 2017-03-28
CPC Classifications: A61M

Claim:
1. Single-use syringe comprising a barrel having an internal surface defining a chamber for retaining a fluid, a plunger formed by an elongated body including a plurality of longitudinal fins and optionally a piston connected to an end of the plunger close to a needle, an 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 an internal surface of the barrel, wherein the barrel has a general external shape of a cylinder of revolution with a constant radius circular base and a variable internal shape, forming a wall of the barrel with variable thickness, generating a chamber inside which the plunger incorporating the plurality of longitudinal fins slides; wherein each of the longitudinal fins of the plunger has a constant height along its entire length but different from that of at least one of the other longitudinal fins, which constant height is suitable in each longitudinal fin so that the plunger can be inserted tightly without the capability of rotating about itself through a space defined by a variable internal radius of the barrel; wherein a length of at least one of the longitudinal fins is also different from a length of at least one of the other longitudinal fins so that the plunger includes a weakened area in the form of a hole at the end of the plunger close to the needle; and wherein the barrel further comprises at least two grooves in the internal surface of the barrel, at least one being located in a distal part and at least one in a proximal part of the barrel with respect to the needle.