Patent ID: 7846135
Filing Date: 2010-12-07
Classification: A61M

Abstract:
1. A syringe comprising: a hollow barrel including an opening at a proximal end of the barrel, an opening at a distal end of the barrel and a fluid chamber disposed within the barrel; a hollow plunger extending into the barrel via the proximal end opening of the barrel and axially movable within the barrel toward and away from the barrel distal end, wherein the plunger includes a removable plug that is frictionally fit and releasably secured to the plunger at an opening disposed at a distal end of the plunger and is movable to disengage with the plunger distal end opening during use of the syringe to facilitate access to a retraction cavity disposed within the plunger; a resilient seal secured around an external wall portion of the plunger near the plunger distal end, wherein the resilient seal includes at least one flexible member that extends beyond the plunger distal end and is biased to at least partially cover and obstruct the plunger distal end opening when the plunger plug is disengaged from the plunger distal end opening; and a needle assembly secured within and at the barrel distal end, the needle assembly including a needle holder with a connector to secure a needle to the needle holder so as to permit the needle to extend through the distal end opening of the barrel; wherein the needle holder is biased toward the proximal end of the barrel and is configured to be forced into the retraction cavity of the plunger upon complete depression of the plunger distally within the barrel, and the plunger includes at least one protrusion that extends from an internal wall surface of the plunger within the retraction cavity and is configured to engage with and limit or prevent movement of portions of the needle assembly that have been forced into the retraction cavity.