Auto-flushing medical fluid injection system

• US 5,643,218 A
• Filed: 08/20/1996
• Issued: 07/01/1997
• Est. Priority Date: 02/15/1994
• Status: Expired due to Fees

• Current Assignee: Lawrence A. Lynn
• Original Assignee: Lawrence A. Lynn
• Inventors: Lynn, Lawrence A., Larkin, Mark E.
• Primary Examiner(s): Millin, Vincent
• Assistant Examiner(s): VANOVER, PERRY
• Application Number:
  US08/697,058
• Time in Patent Office: 315 Days
• Field of Search: 604/89-91, 604/187, 604/191, 604/207-208, 604/218, 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 syringe for the sequential withdrawal of a first liquid and a second liquid. The syringe has a barrel, a proximal piston moveable along the barrel to define a variable volume chamber intermediate the piston and the end of the barrel, and a distal chamber divider piston for separating the variable volume chamber into primary and secondary reservoirs. A flow channel is defined along the syringe for providing flow connection between the primary and secondary reservoirs. An element links the two pistons so that as the proximal piston is moved away from the distal piston, the first liquid enters the first reservoir and thereafter the second liquid enters the secondary reservoir.

Claims

1. An automatic medical fluid injection assembly for the sequential injection of a first liquid and a second liquid, the assembly comprising:

a. a syringe defining a variable volume chamber having a distal end and an opening in said distal end, and further having an internal displacement volume and a piston to vary said internal displacement volume;

b. a chamber divider for separating said internal volume into at least proximal and distal variable volume reservoirs, said chamber divider being movable along said chamber, said proximal reservoir having a maximum volume;

c. a flow channel along said assembly, said flow channel being capable of providing flow connection between the proximal reservoir and the distal reservoir, said flow channel being in fluid communication with said conduit and said 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. an 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 filled with said first liquid, said chamber divider is urged by said element away from said distal end of said chamber to enlarge said distal reservoir and to withdraw said second liquid into said distal reservoir;

f. said flow channel being sized and configured such that after said maximum volume of first liquid has been withdrawn into said proximal reservoir and said second liquid has been withdrawn into said distal reservoir, displacement of said maximum volume of first liquid through said flow channel is sufficient to displace all said second liquid from said syringe when said piston is advanced along said barrel;

g. automatic injection means, said injection means having means for automatically advancing said piston.

2. The assembly of claim 1, wherein said second liquid is a drug solution.

3. The assembly of claim 2, wherein said first liquid is a flush solution.

4. The assembly of claim 1, wherein said second liquid is blood.

5. The assembly of claim 4, wherein said first liquid is a flush solution.

6. The assembly of claim 5, wherein said automatic injection means further includes means for automatically sequentially injecting said second liquid followed by said flush solution, said second liquid comprising a specific volume of a drug solution, said automatic injection means including drug solution volume-selecting means for selectively injecting said specific volume.

7. The assembly of claim 5, further including flush solution volume selecting means for selectively injecting said maximum flush volume.

8. The assembly of claim 1, wherein said first liquid is a flush solution.