Apparatus for Aspirating and Dispensing Liquids in an Automated Analyzer

• US 20080098828A1
• Filed: 10/26/2006
• Published: 05/01/2008
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Beckman Coulter Incorporated (Danaher Corporation)
• Original Assignee: Beckman Coulter Incorporated (Danaher Corporation)
• Inventors: Li, William W., Veiner, Craig R., Del Valle, Roberto, Casey, William J., Cano, Jose M., Gonzalez, Carlos R., Galvez, Santiago
• Granted Patent: US 7,661,326 B2
• Time in Patent Office: Days
• US Class Current: 73/863.73
• CPC Class Codes: G01N 35/1097 characterised by the valves valves in general F16K

Abstract

Apparatus for aspirating and dispensing liquid samples in an analytical instrument, e.g., a hematology instrument, includes a liquid-sampling valve that, while operating to segment and position for dispensing one or more precise volumes of a liquid sample that has been aspirated into the valve by a pump, simultaneously enables the apparatus to be operated in an aspirate/dispense (suck-and-spit) mode in which a liquid sample can be selectively driven through the valve in opposite directions by a pump, e.g., a syringe pump.

Claims

1. A liquid-sampling valve operatively connectable with an aspiration probe and a pump to aspirate liquid from a container and to dispense a plurality of discrete liquid aliquots of the aspirated liquid through said aspiration probe, said liquid-sampling valve comprising:

a shear valve assembly comprising a plurality of confronting and contiguous valve pads arranged side-by-side, at least one of said valve pads being movable with respect to the other of said valve pads to change the relative positions of said valve pads, and each of said valve pads having flow path-defining structure that cooperates with flow path-defining structure of an adjacent valve pad to define at least first, second and third liquid flow paths within said shear valve assembly as the relative positions of said valve pads change, said at least one of said valve pads being movable with respect to the other of said valve pads to define (a) a loading configuration in which a first aliquoting chamber within said shear valve assembly is positioned within said first liquid flow path and becomes filled with a liquid aspirated through said aspiration probe by said pump, and (b) a segmenting/dispensing configuration in which (i) liquid within said first aliquoting chamber is positioned to be acted upon by an external force, whereby such liquid is dispensed from said first aliquoting chamber along said second liquid flow path, and (ii) liquid can be either aspirated or dispensed through said aspiration probe and along said third liquid flow path within said valve assembly by said pump.

2. The liquid-sampling valve as defined by claim 1 wherein said first aliquoting chamber is defined by a bore hole passing through one of said valve pads.

3. The liquid-sampling valve as defined by claim 2 wherein said shear valve assembly comprises three adjacent valve pads, and wherein said bore hole is formed in the middle valve pad of said three valve pads.

4. The liquid-sampling valve as defined by claim 1 wherein a second aliquoting chamber is positioned in said first flow path and also becomes filled with liquid aspirated through said liquid-sampling valve when said liquid-aspirating valve is said loading configuration, and wherein liquid within said second aliquoting chamber is positioned to be acted upon by an external force to dispense such liquid from said second aliquoting chamber along a fourth flow path when said liquid-sampling valve is in said segmenting/dispensing configuration.

5. A liquid-sampling valve adapted for use with, and operatively connected to, an aspiration probe and a pump to aspirate a liquid from a container and to dispense a plurality of discrete liquid aliquots of the aspirated liquid through said aspiration probe, said liquid-sampling valve comprising a shear valve assembly that is structured to enable said aspiration probe to be used in an aspirating-and dispensing mode while said shear valve assembly simultaneously operates to store and position for dispensing one or more precise aliquots of a liquid that has been previously aspirated into said shear valve assembly through said aspiration probe.

6. The liquid-sampling valve as defined by claim 5 wherein said shear valve assembly comprises a plurality of confronting and contiguous valve pads, each of said valve pads having structure that cooperates with structure of an adjacent valve pad to define different liquid flow paths within said shear valve assembly, at least one of said valve pads being movable with respect to the other of said valve pads to define either (a) a loading configuration in which a first aliquoting chamber is positioned within a first flow path and becomes filled with a liquid aspirated through said aspiration probe and through said valve assembly by said pump, and (b) a segmenting/dispensing configuration in which (i) liquid within said first aliquoting chamber is positioned to be acted upon by an external force to dispense such liquid from said first aliquoting chamber along a second flow path, and (ii) liquid can be either aspirated or dispensed through said valve assembly along a third flow path by said pump.

7. The liquid-sampling valve as defined by claim 6 wherein said first aliquoting chamber is defined by a bore hole passing through one of said valve pads.

8. The liquid-sampling valve as defined by claim 7 wherein said shear valve assembly comprises three adjacent valve pads, and wherein said bore hole is formed in the middle valve pad of said three valve pads.

9. The liquid-sampling valve as defined by claim 6 wherein a second aliquoting chamber is positioned in said first flow path and becomes filled with liquid aspirated through said liquid-sampling valve when said liquid-aspirating valve is its loading configuration, and wherein liquid within said second aliquoting chamber is positioned to be acted upon by an external force to dispense such liquid from said second aliquoting chamber along a fourth flow path when said liquid-sampling valve is its segmenting/dispensing configuration.

10. Apparatus for aspirating and dispensing a liquid sample in an automated analytical instrument, said apparatus comprising:

(a) an aspiration probe, operably connected to a pump, and adapted to enter a sample container to aspirate a liquid sample within such container;

(b) a transport system for selectively advancing the aspiration probe in mutually perpendicular planes so that said aspiration probe can aspirate or dispense liquid from or to different containers spaced apart; and

(c) a liquid-sampling valve, operatively connected between said aspiration probe and pump, and comprising structure defining at least one aliquoting chamber for temporarily storing a precise volume of liquid sample to be dispensed;

said pump operatively being selectively operable to either (i) draw a liquid sample through said aspiration probe and through the liquid-sampling valve to fill said aliquoting chamber, or (ii) to dispense an already aspirated liquid sample through said liquid-sampling valve and through aspiration probe, said liquid-sampling valve being selectively operable in either (i) a loading configuration in which a liquid sample aspirated by the aspiration probe under the influence of the pump will pass through the liquid-sampling valve while simultaneously filling said aliquoting chamber thereof, or (ii) a segmenting/dispensing configuration in which liquid within said aliquoting chamber is positioned to be dispensed from said liquid-sampling valve by an external force, while a liquid sample can be either aspirated or dispensed through said aspiration probe and through said liquid-sampling valve by said pump.

11. Apparatus as defined by claim 10 wherein said pump is a stepper-motor controlled syringe pump.

12. Apparatus as defined by claim 10 wherein said shear valve assembly comprises a plurality of confronting and contiguous valve pads, each of said pads having structure that cooperates with structure of an adjacent pad to define different liquid flow paths within said shear valve assembly, at least one of said pads being movable with respect to the other of said pads to define either (a) a loading configuration in which a first aliquoting chamber positioned within a first flow path and becomes filled with a liquid aspirated through said aspiration probe and through said valve assembly by said pump, and (b) a segmenting/dispensing configuration in which (i) liquid within said first aliquoting chamber is positioned to be acted upon by an external force to dispense such liquid from said first aliquoting chamber along a second flow path, and (ii) liquid can be either aspirated or dispensed through said vale assembly along a third flow path by said pump.

13. The liquid-sampling valve as defined by claim 12 wherein said first aliquoting chamber is defined by a bore hole passing through one of said valve pads.

14. The liquid-sampling valve as defined by claim 13 wherein said shear valve assembly comprises three valve pads, and wherein said bore hole is formed in a middle pad of said three valve pads.

15. The liquid-sampling valve as defined by claim 12 wherein a second aliquoting chamber is positioned in said first flow path and becomes filled with liquid aspirated through said liquid-sampling valve when said liquid-aspirating valve is its loading configuration, and wherein liquid within said second aliquoting chamber is positioned to be acted upon by an external force to dispense such liquid from said second aliquoting chamber along a fourth flow path when said liquid-sampling valve is its segmenting/dispensing configuration.

16. Liquid aspirating/dispensing apparatus comprising:

(a) an aspiration probe adapted to penetrate a seal atop a sample container to access a liquid sample within such container;

(b) a shear-valve assembly operatively connected to the aspiration probe and defining at least at least one aliquoting chamber for temporarily storing a precise volume of liquid sample, said shear valve assembly being selectively operable in (i) a loading mode to receive in its aliquoting chamber a liquid sample aspirated by said aspiration probe, and (ii) in a dispense mode to enable a liquid sample within said aliquoting chamber to be dispensed therefrom; and

(c) a syringe pump operatively connected to said shear valve assembly and operable in (i) an aspiration mode in order to draw sample liquid through the aspiration probe and into the aliquoting chamber of the shear valve assembly when the shear valve assembly is operating in its loading mode, and (ii) an aspiration/dispense mode in which it can either aspirate liquid sample from the sample container through the aspiration probe and shear valve assembly to a location downstream of the shear valve assembly or dispense previously aspirated liquid sample from such location downstream of the shear valve assembly through the shear valve assembly and through the aspiration probe.