Liquid proportioning system in a liquid sample analyzer

• US 4,002,269 A
• Filed: 04/02/1975
• Issued: 01/11/1977
• Est. Priority Date: 08/16/1974
• Status: Expired due to Term

• Current Assignee: Technicon Instruments Corporation (Bayer AG)
• Original Assignee: Technicon Instruments Corporation (Bayer AG)
• Inventors: Negersmith, Kent M.
• Primary Examiner(s): Yudkoff, Norman
• Assistant Examiner(s): Hollander, Barry I.
• Application Number:
  US05/564,583
• Time in Patent Office: 650 Days
• Field of Search: 23/230 R, 23/230 B, 23/253 R, 23/259, 222/145, 222/1, 222/318, 137/255-262, 73/423 A
• US Class Current: 222/1
• CPC Class Codes: G01N 1/38 Diluting, dispersing or mixing samples
• CPC Class Codes: G01N 35/08 using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis
• CPC Class Codes: Y10T 436/118339 with formation of a segmented stream

Abstract

A liquid sample analyzer having a first fixed-volume chamber into which a first liquid is flowed filling it for subsequent displacement of the liquid volume therefrom by a second liquid into a substantially larger second fixed-volume chamber through a first port thereof, the second liquid acting as a pilot fluid. Prior to such liquid volume displacement from the first chamber, the second chamber, having an overflow outlet at a location remote with respect to the first port, is washed out and filled to an overflow level by a flow of the second liquid entering the second chamber through a second port. On such displacement of the volume of the first liquid into the second chamber, the last-mentioned volume and a relatively small volume of the second liquid entering the second chamber displace from the second chamber through the aforementioned outlet an equivalent volume of the second liquid, so that a reproducible volume of the first liquid remains in the second chamber with a reproducible volume of the second liquid. In this manner, the volumes of such liquids are precisely proportioned with substantial independence with respect to flow rates. One of the liquids may be a sample and the other may be a diluent. Sample analysis may take place in the second chamber prior to evacuation of the chamber contents therethrough the second port.

Claims

1. A method of proportioning liquids in a fluid sample analyzer, comprising the steps of:

filling a first chamber of fixed-volume with a first liquid;

filling a second larger chamber of fixed-volume with a second liquid to be combined with said first liquid;

displacing the volume of said first liquid in said first chamber into said filled second chamber, using a quantity of said second liquid as a pilot liquid; and

exhausting concurrently a volume of said second liquid by overflow from said second chamber equal to said volume of said first liquid and any pilot fluid introduced into said second chamber.

2. A method as defined in claim 1, further including the step of agitating the combined liquids in said second chamber to mix them.

3. A method as defined in claim 1, further including establishing a vacuum in a third chamber, and withdrawing with such vacuum from said second chamber into said third chamber said combined first and second liquids.

4. A method as defined in claim 1, wherein:

one of said liquids is a sample for analysis of a constituent thereof, and the other of said liquids is a reagent, and further including the step of analyzing the sample subsequent to the combining of said two liquids.

5. A method as defined in claim 1, wherein:

said first liquid is a sample for analysis of a constituent thereof and said second liquid is a diluent, and further including washing out said second chamber with said second liquid from a pressurized source of the latter prior to said filling of said second chamber.

6. A method as defined in claim 1, wherein:

said first liquid is a sample for analysis of a constituent thereof and said second liquid is a reagent, and further including the steps of subsequently withdrawing said combined liquids from said second chamber and analyzing the sample.

7. A method as defined in clim 4, wherein:

said sample is whole blood and said reagent is Drabkin'"'"'s reagent with a lysing agent, and further including the step of agitating the combined liquids in said second chamber to mix them for hemolysis of the erythrocytes of said sample, said second chamber comprising a flowcell, and said analysis being a photometric analysis of the said sample in said flowcell for hemoglobin in said sample.

8. A method as defined in clim 7, further including subsequently displacing the contents of the second chamber for flow thereof through a second flowcell, said analysis including a photometric analysis in said second flowcell for counting the leukocytes in said sample.

9. A method of proportioning liquids in a fluid sample analyzer utilizing a first fixed-volume chamber, a larger second fixed-volume chamber having an overflow outlet, and a controlled fluid coupling between said chambers for placing the latter alternatively in and out of communication with each other, comprising:

filling said first chamber by flowing a first liquid along a conduit having an outlet coupled to said first chamber, while said chambers are out of communication;

filling said second chamber by flowing a second liquid along a conduit having an outlet coupled to said second chamber, while said chambers are out of communication;

flowing as a pilot fluid said second liquid along a conduit having an outlet coupled to said first chamber, while said chambers are in communication;

displacing with said flowing second liquid from the lastmentioned conduit outlet the volume of said first liquid in said first chamber into said filled second chamber for displacement and overflow of an equivalent volume of said second liquid through said overflow outlet, and thereafter placing said chambers out of communication with one another; and

withdrawing the combined volumes of said first and second liquids from said second chamber by flowing said combined liquids along a conduit having an end coupled to said second chamber, while said chambers are out of communication.

10. A liquid porportioning system in a fluid sampler analyzer, comprising:

means for flowing a first liquid along a first conduit for filling means defining a first chamber of fixed volume;

means for flowing a second liquid along a second conduit for filling means defining a second larger chamber of fixed volume;

means for flowing a different quantity of said second liquid as a pilot fluid along a third conduit to said first chamber; and

first means for selectively coupling said first chamber to said second chamber, the last-named means coupling said chambers during said flow of said pilot fluid, such that the volume of said first liquid in said first chamber is displaced into said filled second chamber, said means defining said second chamber comprising means for overflowing a volume of said second liquid from said second chamber equal to the volume of said first liquid and any pilot fluid introduced into said second chamber.

11. Apparatus as defined in claim 10, further including means for agitating the combined liquids in said second chamber to mix them.

12. Apparatus as defined in claim 10, further including means for terminating said flow of said second liquid along said second conduit toward said second chamber, means defining a third chamber, second means selectively coupling said second conduit to said third chamber, and means establishing a vacuum in said third chamber when said second coupling means is closed, the vacuum in said third chamber withdrawing into said third chamber the combined liquids in said second chamber through said second conduit when said second coupling means is open and said first coupling means is closed and said flow of said second liquid in said second conduit toward said second chamber is terminated.

13. Apparatus as defined in claim 10, wherein:

one of said liquids is sample for analysis of a constituent thereof, and the other of said liquids is a reagent, and further including means for analyzing the sample subsequent to the combining of said two liquids.

14. Apparatus as defined in claim 10, wherein:

said first liquid is a sample for analysis of a constituent thereof and said second liquid is a diluent, and further inlcuding a controlled pressurized source of said diluent coupled to said second conduit, said means for flowing said second liquid along said second conduit being operative to wash out said second chamber prior to said filling of said second chamber.

15. Apparatus as defined in claim 10, wherein:

said first liquid is a sample for analysis of a constituent thereof and said second liquid is a reagent, and further including means terminating the flow of said second liquid in said second conduit toward the second chamber, means withdrawing said combined liquids from sad second chamber flow thereof along said second conduit when the flow of said second liquid therein toward the second chamber is terminated, and means for analyzing the sample in said second conduit.

16. In a liquid proportioning system in a fluid sample analyzer, having means defining a first fixed-volume chamber, means defining a larger second fixed-volume chamber having an overflow outlet, and a controlled fluid coupling between said chambers for placing the latter alternately in and out of communication with each oter, the combination of;

means flowing a first liquid along a conduit having an outlet coupled to said first chamber for filling the latter, while said chambers are out of communication,

conduit means comprising at least one liquid conduit having an end coupled to said second chamber;

means flowing a second liquid along said conduit means for filling said second chamber, while said chambers are out of communication;

means flowing said second liquid along a conduit having an outlet coupled to said first chamber to displace the volume of the first liquid in the latter into said filled second chamber, while said chambers are in communication, for displacement and overflow of an equivalent volume of said second liquid through said overflow outlet prior to said chambers being placed out of communication; and

means coupled to said conduit means for withdrawing the combined volumes of said first and second liquids in said second chamber, while said chambers are out of communication.

17. Apparatus for proportioning liquids in a liquid sample analytical system, comprising:

a conduit system including means defining a first and a second fixed-volume chamber in fixed relation to one another each having an inlet and an overflow outlet, means for filling said first chamber with a first liquid and said second chamber with a second liquid of different composition, through the respective inlets to overflow the respective outlets, and means for displacing said first liquid from said first chamber through said second chamber for dispensing from said conduit system through said second chamber inlet in combined form the volumes of said first and second liquids from said chambers, said means defining said chambers and said inlets and outlets thereof comprising a probe including a vertically arranged conduit having a lower opening for ingress and egress of said liquids which forms said inlet of said second chamber, said conduit having intermediate of its ends a lateral outlet forming said second chamber overflow outlet, said second chamber being formed by the portion of said conduit extending between said second chamber inlet and said second chamber overflow outlet, said conduit having a lateral fluid inlet spaced upwardly from the last-mentioned outlet, said first chamber being formed by the portion of the conduit extending between said second chamber overflow outlet and said lateral fluid inlet, said first chamber inlet being in direct communication with said second chamber, and said conduit having an outlet above said lateral fluid inlet and forming said first chamber overflow outlet.

18. Apparatus as defined in claim 17, wherein:

said first and second chambers have different volumes.

19. Apparatus as defined in claim 17, wherein:

said means filling said first and second chambers comprises means establishing at least a partial vacuum connected to the respective outlets of said first and second chambers.

20. Apparatus as defined in claim 17, wherein:

said means for dispensing said liquid volumes comprises means flowing a pilot fluid through said first and second chambers.