Method and apparatus for arterial and venous blood sampling

Claim 1

An apparatus for use in conjunction with a system which is closed to the atmosphere and interconnected invasively to a patient for obtaining a blood sample from the patient, said system being characterized by having a catheter adapted to be inserted into a vein or artery of the patient, said apparatus comprising proximal and distal, spaced apart access devices operably interconnected by a conduit having a fluid passageway, each of said access devices being independently accessible to withdraw fluid from within the system, said proximal access device comprising a body having an upper and lower chamber, said lower chamber having first and second fluid ports and sealing means carried by said upper chamber for sealing said lower chamber relative to atmosphere, said sealing means being penetratable by a needle of a syringe to gain access to said lower chamber, said proximal access device permitting smooth, laminar fluid flow therethrough and including first connector means for interconnecting said first fluid port of said body of said proximal access device with the catheter of the system and further including means for interconnecting said second fluid port of said body of said proximal device with said conduit, said distal access device comprising a chamber in communication with said fluid passageway of said conduit and means for accessing said chamber whereby said chamber of said distal access device can be accessed to withdraw from the apparatus all fluid contained between the catheter and said chamber of said distal access device and to withdraw blood from the patient in a quantity sufficient to draw blood past said first chamber of said proximal access device so that said lower chamber of said proximal access device can be accessed to withdraw therefrom undiluted blood contained therewithin, in a manner such that when said sample is accessed from said proximal access device, the system is not opened to atmosphere.

Claim 2

An apparatus for use in conjunction with a system which is closed to the atmosphere and interconnected invasively to a patient for obtaining a blood sample from the patient, said system being characterized by having a catheter adapted to be inserted into a vein or artery of the patient, said apparatus comprising proximal and distal, spaced apart access devices operably interconnected by a conduit having a fluid passageway, each of said access devices being independently accessible to withdraw fluid from within the system, said proximal access device comprising a body having an upper and lower chamber, said lower chamber having first and second fluid ports and sealing means carried by said upper chamber for sealing said lower chamber relative to atmosphere, said sealing means being penetratable by a needle of a syringe to gain access to said lower chamber, said proximal access device permitting smooth, laminar fluid flow therethrough and including first connector means for interconnecting said first fluid port of said body of said proximal access device with the catheter of the system and further including means for interconnecting said second fluid port of said body of said proximal device with said conduit, said distal access device comprising a chamber in communication with said fluid passageway of said conduit and means for accessing said chamber whereby said chamber of said distal access device can be accessed to withdraw from the apparatus all fluid contained between the catheter and said chamber of said distal access device and to withdraw blood from the patient in a quantity sufficient to draw blood past said first chamber of said proximal access device so that said lower chamber of said proximal access device can be accessed to withdraw therefrom undiluted blood contained therewithin, in a manner such that when said sample is accessed from said proximal access device, the system is not opened to atmosphere.

Claim 8

A method of obtaining a blood sample from a patient in conjunction with an atmospherically sealed system which is interconnected invasively with the patient and which comprises a catheter inserted into either a vein or artery of the patient and proximal and distal operably interconnected access devices in communication with the catheter, the proximal access device permitting smooth, laminar fluid flow therethrough, said method comprising the steps of: (a) accessing the distal access device; (b) removing the fluid contained within the system between said distal access device and the catheter; (c) drawing undiluted blood from the patient to fill the system between the catheter and said distal access device with the undiluted blood of the patient; (d) accessing the proximal access device in a manner such that the system is not opened to atmosphere; and (e) drawing a predetermined volume of undiluted blood.

Claim 9

A method of obtaining a blood sample from a patient in conjunction with an atmospherically sealed system which is interconnected invasively with the patient and which comprises a catheter inserted into either a vein or artery of the patient and proximal and distal operably interconnected access devices in communication with the catheter, the proximal access device permitting smooth, laminar fluid flow therethrough, said method comprising the steps of: (a) accessing the distal access device; (b) removing the fluid contained within the system between said distal access device and the catheter; (c) drawing undiluted blood from the patient to fill the system between the catheter and said distal access device with the undiluted blood of the patient; (d) accessing the proximal access device in a manner such that the system is not opened to atmosphere; and (e) drawing a predetermined volume of undiluted blood.