Patent ID: 9649444
Date: 2017-05-16
CPC Classifications: A61M

Claim:
1. A method of positively displacing fluid from and preventing reflux within a syringe barrel, said method comprising the steps of: (a) providing a stopper comprising a main body having a closed front end, a first body portion having a first diameter, a second body portion having a second diameter which is larger than said first diameter, and a core member integrally formed with said main body adjacent said closed front end, said core member including a nose portion, said stopper further comprising a shoulder extending around a perimeter of said first body portion of said main body, and a skirt extending about said first body portion of said main body, said skirt cooperating with said shoulder for trapping at least one air pocket therein; (b) advancing the stopper through the syringe barrel until the nose portion of the core member contacts an outlet opening at the forward end of the syringe barrel; (c) applying additional force to the stopper to compress the nose portion and increase the pressure within said at least one air pocket; and (d) releasing the force on the stopper to release the seal between the nose portion and the outlet opening at the forward end of the syringe while maintaining the main body of the stopper in an advanced position relative to a starting position within the syringe barrel, such that the increased pressure within the at least one air pocket causes any trapped fluid to be expelled through said outlet opening.