US 5,549,569 A · Ex vivo blood isolation system

Abstract

A system for the sequential and repetitive aspiration and injection of fluid. The system includes a syringe having an internal volume, a piston to vary the internal volume and a chamber divider for separating the internal volume into proximal and distal reservoirs. The chamber divider is moveable along the chamber and is positioned adjacent the distal end of the chamber prior to withdrawal of fluid into the syringe. The proximal reservoir has a maximum displacement volume for receiving fluid. A flow channel provides flow between the proximal and distal reservoirs and a valve disables and enables flow therethrough. A tensile element links the piston and the chamber divider so that after the piston is moved and the proximal reservoir is filled with a first liquid, the chamber divider is pulled away from the distal end of the syringe to enlarge the distal reservoir and draw the blood into the distal reservoir. A conduit is connected with the syringe and is in communication with the patient's blood vessel and contains the first liquid. The flow channel and the conduit are sized and configured such that after the maximum volume of first liquid has been withdrawn into the proximal reservoir and the blood has been withdrawn into the distal reservoir, the maximum volume of first liquid is substantially free from blood, and subsequent displacement of the maximum volume of first liquid back through the valve is sufficient to displace all the blood from the syringe when the piston is advanced.

Claims18

Dependent claims

A system for the sequential and repetitive aspiration and injection of a first liquid and blood, the system comprising:

a. a syringe having a variable volume chamber having a distal end and an opening in said end, and further having an internal displacement volume and piston to vary said internal displacement volume;
b. a chamber divider for separating said internal volume into at least first proximal and second distal variable volume reservoirs, said chamber divider being moveable along said chamber, said chamber divider being positioned adjacent said end prior to withdrawal of said first liquid into said syringe, said first proximal reservoir having a maximum displacement volume for receiving said first liquid;
c. a flow channel along said syringe, said flow channel being capable of providing flow connection between the proximal reservoir and the distal reservoir;
d. a valve capable of at least one disabling and enabling flow between said proximal reservoir and said distal reservoir through said flow channel;
e. a tensile element for linking said piston and said chamber divider so that when said piston is moved away from said chamber divider, and said proximal reservoir is at least partially filled with said first liquid, said chamber divider is urged by said tensile element away from said distal end of said chamber to enlarge said distal reservoir and to withdraw said blood into said distal reservoir;
f. a conduit having a distal terminal, said conduit being in fluid connection with said chamber and in communication with the blood vessel of a patient and containing said first liquid intermediate said chamber and said distal terminal;
g. said flow channel and said conduit being sized and configured such that after said maximum volume of first liquid has been withdrawn into said proximal reservoir and said blood has been withdrawn into said distal reservoir, said maximum volume of first liquid is substantially free from blood, and subsequent displacement of said maximum volume of first liquid back through said valve is sufficient to displace all said blood from the syringe when said piston is advanced along said chamber so that upon repetitive withdrawal and advancement of said piston, blood is not retained within said syringe.

4 more elements

A system for sequentially and repetitively aspirating a first solution into a primary reservoir and a second solution comprising blood into a secondary reservoir, the system comprising:

a. a syringe having a cylindrical barrel defining a bore having a distal end, said distal end having an opening through said distal end, said bore being in fluid connection with said opening;
b. a piston sized to be received tightly within said bore and to seal about said bore intermediate said piston and said distal end, said piston having a handle for movement of said piston along said bore to define a variable volume chamber within said bore, said piston further comprising a proximal portion and a distal portion, said proximal portion being connected to said distal portion by an element between said proximal portion and said distal portion, said element being retractable by retraction of said proximal portion to an extended position wherein retraction force is exerted through said element upon said distal portion, said proximal portion being moveable away from said distal portion to define a primary variable volume reservoir intermediate said portions and to draw said first solution into said primary reservoir, said primary reservoir having a maximum volume, said distal portion being movable along said bore and away from said distal end when said handle is retracted and when said element is extended to define said secondary variable volume reservoir intermediate said distal portion and said distal end, said first solution being trapped within said primary reservoir by said proximal and said distal portions when said element is retracted to said extended position, said distal portion being moveable toward said distal end when said primary reservoir is filled with said first solution, said first solution exerting hydraulic force against said distal portion to urge said distal portion toward said distal end when said proximal portion is moved against said primary reservoir;
c. a flow channel for providing flow communication between said primary reservoir and said secondary reservoir, said trapped first solution escaping from said primary reservoir through said flow channel when said distal portion has been advanced to a position adjacent said distal end and when said proximal portion is further advanced toward said distal portion, said first solution within said primary reservoir functioning to flush said secondary reservoir free of blood;
d. a conduit having a distal terminal, said conduit being in fluid connection with said chamber and in communication with the blood vessel or a patient and containing said first solution intermediate said chamber and said distal terminal;
e. said flow channel and said conduit being sized and configured such that after said maximum volume of first solution has been withdrawn into said proximal reservoir and said blood has been withdrawn into said distal reservoir, said maximum volume of first solution is substantially free from blood, and subsequent displacement of said maximum volume of first solution back through said valve is sufficient to displace all said blood from the syringe when said piston is advanced along said barrel so that upon repetitive withdrawal and advancement of said piston, blood is not retained within said syringe.

2 more elements

A system for isolating a volume of undiluted blood within a conduit, system comprising

a. a conduit having a blood testing portion and further having a distal end for fluid connection with a blood vessel, said conduit having an internal volume filled with flush solution;
b. a multi-compartment syringe including a proximal reservoir and a distal reservoir, said proximal reservoir having a target volume, said syringe being connected to said conduit, said conduit defining a first internal volume intermediate said syringe and said distal end;
c. said first internal volume of said conduit being sufficient to prevent blood from flowing from said blood vessel into said proximal reservoir when said target volume of flush solution is displaced into said proximal reservoir from said conduit;
d. said conduit defining a second volume intermediate said sampling port and said blood vessel, and wherein said target volume of said proximal reservoir is greater than said second volume;
e. said distal reservoir having a variable volume and defining a storage volume for mixed blood and flush solutions and wherein the sum of said target volume of said proximal reservoir and said storage volume of said distal reservoir is sufficiently greater than said second volume of said conduit such that upon withdrawal of said sum into said syringe and the displacement of blood into said conduit in response to said withdrawal, said second volume of flush solution is substantially displaced from intermediate said sampling port and said blood vessel by undiluted blood from said blood vessel.

2 more elements

Dependencies are inferred from the claim text.

Ex vivo blood isolation system

Life of this patent

Ex vivo blood isolation system

Life of this patent

Abstract

Claims18