Ex vivo blood isolation system

• US 5,549,569 A
• Filed: 03/30/1995
• Issued: 08/27/1996
• Est. Priority Date: 02/15/1994
• Status: Expired due to Term

• Current Assignee: Lawrence A. Lynn
• Original Assignee: Lawrence A. Lynn
• Inventors: Lynn, Lawrence A., Larkin, Mark E.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): Van Over, Perry E.
• Application Number:
  US08/413,966
• Time in Patent Office: 516 Days
• Field of Search: 604/191, 604/89-91, 604/187, 604/218, 604/207-208, 604/238, 604/122-125, 128/760, 128/762
• US Class Current: 604/191
• CPC Class Codes: A61J 1/201 having one piercing end
• CPC Class Codes: A61J 1/2037 having valve means
• CPC Class Codes: A61J 1/2055 having gripping means
• CPC Class Codes: A61J 1/2058 having multiple connecting ports
• CPC Class Codes: A61J 1/2062 with directional valves
• CPC Class Codes: A61J 1/2072 for internal venting
• CPC Class Codes: A61J 1/2096 Combination of a vial and a syringe for transferring or mixing their contents
• CPC Class Codes: A61M 2005/1403 Flushing or purging
• CPC Class Codes: A61M 2005/1787 Syringes for sequential delivery of fluids, e.g. first medicament and then flushing liquid
• CPC Class Codes: A61M 2005/3104 Caps for syringes without needle
• CPC Class Codes: A61M 2005/3117 Means preventing contamination of the medicament compartment of a syringe
• CPC Class Codes: A61M 2005/3128 Incorporating one-way valves, e.g. pressure-relief or non-return valves
• CPC Class Codes: A61M 2005/3132 having flow passages for injection agents at the distal end of the barrel to bypass a sealing stopper after its displacement to this end due to internal pressure increase
• CPC Class Codes: A61M 2005/31598 having multiple telescopically sliding coaxial pistons encompassing volumes for components to be mixed
• CPC Class Codes: A61M 2005/3223 Means impeding or disabling repositioning of used needles at the syringe nozzle
• CPC Class Codes: A61M 5/002 Packages specially adapted therefor, e.g. for syringes or needles, kits for diabetics needle protection, e.g. caps, A61M5/3202; for sharps A61B50/3001
• CPC Class Codes: A61M 5/1782 Devices aiding filling of syringes in situ combination of a vial and a syringe for transferring or mixing their contents A61J1/2096, filling of medical containers in general B65B3/003
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/2429 by telescoping of ampoules or carpules with the syringe body
• CPC Class Codes: A61M 5/31596 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/347 : rotatable, e.g. bayonet or screw A61M5/344 takes precedence

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.

Claims

1. 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.

2. The syringe of claim 1 wherein said chamber divider is a second piston and wherein said valve comprises said chamber divider for disabling flow between said proximal reservoir and said distal reservoir.

3. The syringe of claim 1 wherein said tensile element having a maximum extended length, said length defining the maximum displacement volume within said proximal reservoir.

4. 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.

5. 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.

6. The system of claim 5 further including a fluid source in flow connection with said conduit, said fluid source having an elevated fluid pressure relative to said conduit.

7. The system of claim 6 further including a 3 way valve positioned intermediate said conduit, said syringe, and said fluid source for selective fluid connection between at least said fluid source and said conduit and further between said syringe and said conduit.

8. The system of claim 6 further including a pressure transducer mounted adjacent said conduit for monitoring pressure within said conduit.

9. The system of claim 6 further including an ex vivo blood testing monitor mounted adjacent said blood testing portion of said conduit.

10. A system for automatically separating flush solution from blood within a syringe, the 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 for storing flush solution, 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 distal reservoir having a minimum volume, the sum of said first internal volume of said conduit and said minimum volume of said distal reservoir being sufficiently greater than said target volume of said proximal reservoir, so that upon displacement of said target volume of flush solution into said proximal reservoir from said conduit, blood from said blood vessel flows into said conduit and said distal reservoir but blood does not flow into said proximal reservoir so that upon said displacement, flush solution can be automatically separated from blood within said syringe.

11. The system of claim 10 wherein said distal reservoir has a variable volume and defines a storage volume for storing mixed blood and flush solution, said target volume and said storage volume into said syringe from said conduit, sufficient blood from said blood vessel flows into said conduit in response to said withdrawal to displace substantially all flush solution from said blood testing portion.

12. The system of claim 11 wherein said target volume comprises the maximum displacement volume of said proximal reservoir.

13. In a blood isolation system for use with a catheter having a set internal volume, the system functioning for isolation of a volume of undiluted blood within a conduit, the system further including a conduit having a sampling port and further having a distal end for fluid connection with a blood vessel through a catheter, said conduit having an internal lumen filled with flush solution, said conduit further defining a first internal conduit volume intermediate said sampling port and said blood vessel, improvements comprising:

a. a multi-compartment syringe including a proximal reservoir and a distal reservoir, said proximal reservoir having a target volume, said syringe being in fluid connection with said conduit and mounted with said conduit;

b. said distal reservoir having a variable volume and defining a storage volume for storage of mixed blood and flush solution;

c. the sum of said target volume of said proximal reservoir and said storage volume of said distal reservoir being sufficiently greater than said first internal volume of said conduit and said set volume of said catheter such that upon withdrawal of said sum into said syringe and the displacement of blood into said conduit in response to said withdrawal, said first volume of flush solution is substantially displaced from intermediate said sampling port and said blood vessel by undiluted blood from said blood vessel.

14. The system of claim 13 wherein said target volume is the maximum displacement volume of proximal reservoir.

15. A method for repetitively accessing undiluted blood, said method including steps of:

a. disposing a conduit containing liquid in fluid connection with a blood vessel;

b. connecting a multi-compartment syringe into fluid connection with said conduit, said syringe having a proximal reservoir and a distal reservoir;

c. withdrawing flood free liquid from said conduit into said proximal reservoir and storing said blood free liquid within said proximal reservoir;

d. withdrawing a volume of a mixture of blood and liquid into said distal reservoir, the volume of said mixture being sufficient to draw on diluted blood onto said conduit;

e. accessing said undiluted blood;

f. returning said mixture of blood and liquid from said distal reservoir into said conduit;

g. flushing said distal reservoir free of blood by flowing said blood free liquid from said proximal reservoir into said distal reservoir.

16. The method of claim 15 further including the steps of:

a. disposing a high pressure fluid source in fluid connection with said conduit;

b. after the step of flushing said distal reservoir, further activating flow from said high pressure fluid source into said conduit flush said conduit free of blood.

17. A method for repetitively accessing undiluted blood, said method including steps of:

a. disposing a conduit containing liquid in fluid connection with a blood vessel;

b. connecting a multi-compartment syringe into fluid connection with said conduit, said syringe having a proximal reservoir and a distal reservoir;

c. displacing blood into said conduit by withdrawing liquid from said conduit into said proximal reservoir;

d. discontinuing said withdrawing of said liquid before substantially any blood enters said proximal reservoir and storing said liquid within said proximal reservoir;

e. withdrawing a volume of a mixture of blood and liquid into said distal reservoir, the volume of said mixture being sufficient to draw undiluted blood into said conduit;

f. accessing said undiluted blood;

g. returning said mixture of blood and liquid from said distal reservoir into said conduit;

h. flushing said distal reservoir free of blood by flowing said liquid from said proximal reservoir into said distal reservoir.

18. A method of sampling undiluted blood into a blood collector from a blood sampling port of a conduit in fluid connection with a blood vessel, said conduit being filled with flush solution, said method comprising:

a. a disposing syringe in fluid connection with said conduit, said syringe having a proximal reservoir and a distal reservoir;

b. withdrawing said flush solution from said conduit into said proximal reservoir, discontinuing said withdrawal of flush solution into said proximal reservoir before blood enters said proximal reservoir;

c. withdrawing a mixture of blood and flush solution into said distal reservoir until diluted blood is displaced into said conduit adjacent said sampling port;

d. flowing undiluted blood from said sampling port into said blood collector.