Apparatus for mixing fluids for analysis

• US 5,840,254 A
• Filed: 06/02/1995
• Issued: 11/24/1998
• Est. Priority Date: 06/02/1995
• Status: Expired due to Fees

• Current Assignee: Drew Scientific Holdings, Inc.
• Original Assignee: CDC Technologies, Inc. (Escalon Medical Corporation)
• Inventors: Skiptunas, Steven, Carver, Edward Lawrence Jr., DeCava, David Charles
• Primary Examiner(s): ALEXANDER, LYLE
• Application Number:
  US08/458,701
• Time in Patent Office: 1,271 Days
• Field of Search: 436/51-53, 436/55, 436/49-50, 422/62-63, 422/68.1, 422/81
• US Class Current: 422/68.1
• CPC Class Codes: G01N 1/38 Diluting, dispersing or mixing samples
• CPC Class Codes: G01N 35/085 Flow Injection Analysis
• CPC Class Codes: G01N 35/1097 characterised by the valves valves in general F16K
• CPC Class Codes: Y10T 436/117497 with a continuously flowing sample or carrier stream

Abstract

In an apparatus for fluid analysis, such as hematologic analysis, a plurality of reagent-mixture components are each injected by a respective pump through a valve matrix and into a flow-injection unit. The flow-injection unit defines a mixing chamber including a plurality of protuberances or nubs projecting inwardly toward the center of the chamber, and spaced relative to each other both axially and radially. As the reagent-mixture components are injected into the mixing chamber, the nubs agitate the fluid flow and create turbulence, thereby dispersing the reagent-mixture components and in turn mixing the components together to create a reagent mixture. The flow rates of the reagent-mixture components are adjusted in order to select the reagent-mixture ratio as the components are combined in the flow-injection unit to thereby create the selected reagent mixture. Upon passage through the flow-injection unit, the reagent mixture is injected into a sensing unit for analyzing a particle distribution of the mixture.

Claims

1. An apparatus for at least one of particle and chemical analysis of reagent mixtures having a plurality of reagent-mixture components, comprising:

means for pumping each of a plurality of reagent-mixture components in a respective stream at a respective flow rate;

means for introducing at least one reagent-mixture component into a stream of at least one other reagent-mixture component to mix the plurality of reagent-mixture components into a combined reagent-mixture stream, said means including an elongated mixing chamber defining an upstream end and a downstream end, at least one inlet port located at the upstream end of the mixing chamber and coupled in fluid communication with the pumping means for introducing a plurality of reagent-mixture component streams into the mixing chamber, an outlet port located downstream of the at least one inlet port for receiving the combined reagent-mixture stream, and a plurality of raised surface portions spaced relative to each other and projecting inwardly into the mixing chamber and transverse relative to its elongated direction for creating turbulence within the mixing chamber to facilitate mixing of the reagent-mixture components into the combined reagent-mixture stream; and

means coupled in fluid communication with the outlet port for at least one of (i) chemically analyzing and (ii) analyzing a particle distribution of the combined reagent-mixture stream.

2. An apparatus as defined in claim 1, wherein a first inlet port is aligned with an axis of the mixing chamber for injecting the respective reagent-mixture component on a flow path substantially aligned with the axis of the mixing chamber.

3. An apparatus as defined in claim 1, wherein the mixing chamber is defined by at least one axially-elongated surface extending between the upstream and downstream ends, and the raised surface portions are defined by a plurality of protuberances projecting inwardly from the axially-elongated surface toward approximately the axis of said surface.

4. An apparatus as defined in claim 1, wherein the raised surface portions are at least one of (i) axially spaced relative to each other and (ii) radially spaced relative to each other.

5. An apparatus as defined in claim 1, wherein each raised surface portion defines an axis oriented approximately perpendicular to an elongated axis of the mixing chamber.

6. An apparatus as defined in claim 1, wherein the means for introducing includes an elongated axis extending between the upstream and downstream ends of the elongated mixing chamber, a first inlet port coupled in fluid communication with the pumping means and defining a first inlet axis oriented transverse to the elongated axis of the mixing chamber for introducing a first reagent-mixture component stream into the mixing chamber along the first inlet axis, and a second inlet port angularly spaced relative to the first inlet port, wherein the second inlet port defines a second inlet axis oriented transverse to the elongated axis, and is coupled in fluid communication with the pumping means for introducing a second reagent-mixture component stream into the mixing chamber in a different flow direction than the first reagent-mixture component stream to thereby create turbulence in the combined reagent-mixture stream.

7. An apparatus as defined in claim 1, wherein the means for introducing includes an elongated axis extending between the upstream and downstream ends of the elongated mixing chamber,

a first inlet port located at the upstream end of the mixing chamber and coupled in fluid communication with the pumping means, and defining a first inlet axis for introducing a first reagent-mixture component stream into the mixing chamber along the first inlet axis,

a second inlet port located downstream of the first inlet port and coupled in fluid communication with the pumping means, and defining a second inlet axis for introducing a second reagent-mixture component stream into the mixing chamber along the second inlet axis, wherein one of the first and second inlet axes is inclined relative to the other and the elongated axis for introducing the respective reagent-mixture component stream into the mixing chamber in a different flow direction than the other reagent-mixture component stream to thereby create turbulence in the combined reagent-mixture stream.

8. An apparatus as defined in claim 1, comprising a plurality of inlet ports, each inlet port being coupled in fluid communication with the mixing chamber either upstream or downstream of an adjacent inlet port.

9. An apparatus as defined in claim 8, wherein each inlet port is coupled in fluid communication with the mixing chamber at a location spaced radially with respect to an adjacent inlet port.

10. An apparatus as defined in claim 1, wherein the mixing chamber defines a diffusion portion and at least one mixing ball received within the diffusion portion for facilitating mixture of the reagent-mixture components.

11. An apparatus as defined in claim 10, wherein the mixing chamber further defines an axially-elongated portion coupled in fluid communication with the diffusion portion.

12. An apparatus as defined in claim 1, wherein the mixing chamber includes a plurality of said raised surface portions and adjacent depressed surface portions forming at least two diffusion chambers and a relatively constricted aperture extending between the diffusion chambers.

13. An apparatus as defined in claim 12, wherein each diffusion chamber is defined by a radial surface.

14. An apparatus as defined in claim 13, wherein the radial surface is substantially spherical.

15. An apparatus as defined in claim 1, wherein the raised surface portions are defined by a plurality of baffles, each baffle projecting inwardly generally toward a central axis of the mixing chamber.

16. An apparatus as defined in claim 15, wherein each baffle defines a plurality of apertures for receiving fluid flow therethrough.

17. An apparatus as defined in claim 15, wherein each baffle also projects generally toward the upstream end of the mixing chamber.

18. An apparatus as defined in claim 1, wherein the raised surface portions are defined by a plurality of tubes, each tube defining a respective inlet port and projecting into the mixing chamber for introducing a respective reagent-mixture component into the mixing chamber.

19. An apparatus as defined in claim 18, wherein each tube defines a plurality of apertures on an end portion projecting into the mixing chamber for introducing the respective reagent-mixture component through the apertures and into the mixing chamber.

20. An apparatus as defined in claim 18, wherein the end portion of each tube projecting into the mixing chamber is oriented generally toward the upstream end of the mixing chamber.

21. An apparatus as defined in claim 18, wherein the tubes are at least one of (i) axially spaced relative to each other and (ii) radially spaced relative to each other.

22. An apparatus as defined in claim 18, wherein each tube is oriented and projects into the mixing chamber in a substantially upstream direction for introducing the respective reagent-mixture component toward a substantially upstream direction.

23. An apparatus as defined in claim 1, further comprising:

means for forming a plurality of different selected reagent mixtures in the combined reagent-mixture stream, wherein each selected reagent mixture is formed by adjusting the flow rate of at least one of a plurality of reagent-mixture components in accordance with a flow-rate ratio of reagent-mixture components corresponding to the selected reagent mixture.

24. An apparatus as defined in claim 23, further comprising a control unit coupled to the means for pumping and including a database of predetermined reagent-mixture ratios, wherein each predetermined reagent-mixture corresponds to one or more species, and the control unit is responsive to an input for a selected species to control the means for pumping to pump the reagent-mixture components of the respective reagent-mixture ratio of the selected species ay a flow-rate ratio corresponding to the reagent-mixture ratio.

25. An apparatus as defined in claim 23, further comprising a plurality of reagent-mixture component chambers, wherein each reagent-mixture component chamber contains a respective reagent-mixture component and is coupled in fluid communication with the means for pumping for supplying reagent-mixture components to the means for pumping.

26. An apparatus as defined in claim 23, wherein the selected reagent mixture is formed by adjusting the flow rates of at least two reagent-mixture components in accordance with the respective flow-rate ratio.

27. An apparatus as defined in claim 23, wherein the means for pumping includes a plurality of pumps, each pumping a respective reagent-mixture component, and the means for forming the plurality of different selected reagent mixtures is coupled to and controls the flow rate of each pump to in turn control the flow rate of at least one of the plurality of reagent-mixture components in accordance with the flow-rate ratio of the reagent-mixture components corresponding to the selected reagent mixture.

28. An apparatus as defined in claim 27, further comprising a plurality of pump motors, each pump motor being coupled to a respective pump to control the flow rate of the pump and a respective reagent-mixture component.