Patent ID: 6984222
Filing Date: 2006-01-10
Classification: A61M

Abstract:
1. A plunger for use in a syringe comprising a body portion having an inner wall, a discharge end and a transition region defined between the body portion and the discharge end, the plunger comprising: a base comprising a side portion that is tapered so that the diameter of the side portion of the base decreases from a rearward axial position to a forward axial position thereof; and a plunger surface disposed on at least a portion of the base, the plunger surface comprising a seal portion operably associated with the side portion of the base, the seal portion comprising an exterior surface in contact with the inner wall of the syringe and an inner wall that is tapered so that the diameter of the seal portion inner wall decreases from a rearward axial position to a forward axial position thereof, wherein increases in pressure caused by movement of the plunger in the syringe compresses the seal portion between the inner wall of the syringe and the side portion of the base to create a dynamic seal between the seal portion and the inner wall of the syringe.