초록 ▼

A blood collection assembly for receiving a blood sample from a patient but for preventing the blood from flowing out once it has been received. This assembly includes an evacuated receptacle, such as a blood collecting tube, for the reception and retention of a sample of blood. An opening is includ

A blood collection assembly for receiving a blood sample from a patient but for preventing the blood from flowing out once it has been received. This assembly includes an evacuated receptacle, such as a blood collecting tube, for the reception and retention of a sample of blood. An opening is included in the receptacle into which a penetrable stopper is sealably positioned to maintain the evacuated condition inside the receptacle. Located inside the evacuated receptacle is a unidirectional flow valve through which blood entering the receptacle must pass. When the stopper is penetrated by a sharp cannular instrument carrying blood the pressure on the side of the valve facing the stopper is greater than the pressure in the evacuated receptacle, thereby causing the valve to open so that blood flowing from the instrument flows through the valve and into the receptacle. If the pressure in the receptacle changes so that it is greater than the pressure on the other side of the valve, the valve is operable to close to thereby prevent blood from backflowing into the patient.

대표청구항 ▼

A blood collection assembly for receiving a blood sample from a patient, but for preventing the blood from flowing out once it has been received comprising: a receptacle for the reception and retention of a sample of blood having a longitudinal axis; said receptacle having an inside pressure less th

A blood collection assembly for receiving a blood sample from a patient, but for preventing the blood from flowing out once it has been received comprising: a receptacle for the reception and retention of a sample of blood having a longitudinal axis; said receptacle having an inside pressure less than normal atmospheric pressure outside said receptacle thereby establishing a pressure gradient across said receptacle, said receptacle including an opening therein; a penetrable stopper sealably positioned in said opening to maintain said pressure gradient across said receptacle; and, a unidirecitonal flow-valve means disposed on said stopper inside said receptacle through which blood entering said receptacle must pass, said valve means spaced apart from the penetrable surface of said stopper and defining between said valve means and said penetrable surface, a chamber for receiving a tip of a sharp cannula instrument, and defining between said valve means and the interior of said receptacle a downstream portion; said valve means adapted to open for blood flow in response to the introduction of the tip of said cannula instrument into said chamber through said penetrable stopper, the pressure of said upstream portion being greater than said downstream portion following said penetration, and said valve means adapted to close if the pressure of said downstream portion equals or exceeds the pressure of said upstream portion; wherein said flow valve means includes an annular flange disposed on said stopper in said chamber defining a valve seat; a resiliently operable valve member disposed in said chamber downstream of said valve seat, said valve member remaining sealably closed against said valve seat when the pressure in said receptacle equals or exceeds the pressure in said chamber, said valve member being resiliently flexible to move away from said valve seat when the pressure in said chamber is greater than the pressure in the remainder of said receptacle thereby allowing blood to flow into said receptacle; wherein said valve member includes a substantially flat sealing surface substantially perpendicular to the longitudinal axis for contact with said valve seat and a plurality of spaced apart concave spring legs deformable toward the stream axis projecting substantially downstream from said sealing surface to serve as resilient supports for the same, the free ends of said legs being secured to said stopper so that the sealing surface engages said valve seat when said legs are under spring compression, whereby when the pressure in the space is greater than the pressure inside the receptacle said spring legs are urged under further compression to move said sealing surface away from said valve seat so that blood flows in the gaps between the spaced apart legs into the receptacle, and when the pressure inside the receptacle equals or exceeds the pressure inside the chamber, said legs are released from said further compression thereby urging said sealing surface back into contact with said valve seat to prevent blood from backflowing into said chamber.