Abstract: In an apparatus for fluid 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. As the reagent-mixture components are injected into the mixing chamber, the nubs agitate the fluid flow, 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.

Abstract: An apparatus is provided for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.

Abstract: An apparatus is provided for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.

Abstract: An improved displacement-type syringe has a housing, a substantially fixed seal, a solid or closed-tip plunger, an internal passageway formed between the housing and the plunger, and at least two ports on the housing with at least one port located at each end of the passageway for the passage of fluids and the elimination of gas. The syringe may be mounted in apparatus over a wide range of fixed inclination angles and remain substantially impervious to gas accumulation.

Abstract: In a cuvette for performing a diagnostic test on a specimen, a base defines a first chamber for receiving a reagent, and a second chamber for receiving a test specimen. The second chamber is defined by four side surfaces forming a rectangular configuration, and a base surface extending between the side surfaces. The base surface defines a frangible wall which is breakable in order to place the first chamber in fluid communication with the second chamber. A cover is coupled to the base and is moveable between an open position spaced away from the second chamber for permitting introduction of the specimen into the second chamber, and a closed position overlying and enclosing the second chamber. A self-aligning piercing member is provided on the cover and defines a tip engageable with the base surface of the second chamber upon movement of the cover into the closed position to thereby break the frangible wall, and in turn allow the test specimen to mix with the reagent in the second chamber.

Abstract: A method and apparatus are provided for differentiating cells in an automated particle analyzer, such as for use in hematological analysis, by measuring apparent cell size (or volume), membrane integrity and intracellular complexity ("voltaic fragility"). The cells are suspended in a selected reagent mixture including an electrolytic fluid, such as diluent, and if necessary, one or more membrane-modifying agents are selected and mixed in relative quantities in order to selectively alter the membrane structure (i.e., the membrane integrity) of certain cells and thereby enhance cell discrimination. A predetermined dc voltage is applied across a sensing orifice to thereby create a dc electric field within and around the orifice, and the reagent mixture is passed through the center of the orifice.

Abstract: In a cuvette for performing a diagnostic test on a specimen, a base defines a first chamber for receiving a reagent, and a second chamber for receiving a test specimen. The second chamber is defined by four side surfaces forming a rectangular configuration, and a base surface extending between the side surfaces. The base surface defines a frangible wall which is breakable in order to place the first chamber in fluid communication with the second chamber. A cover is coupled to the base and is moveable between an open position spaced away from the second chamber for permitting introduction of the specimen into the second chamber, and a closed position overlying and enclosing the second chamber. A self-aligning piercing member is provided on the cover and defines a tip engageable with the base surface of the second chamber upon movement of the cover into the closed position to thereby break the frangible wall, and in turn allow the test specimen to mix with the reagent in the second chamber.

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.

Abstract: An apparatus is provided for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.

Abstract: In a valve assembly exhibiting zero dead volume the port head is mounted on a solenoid and defines an inlet port on one side of the valve seat, and two outlet ports on the opposite side of the valve seat. A flexible diaphragm is seated across the valve seat between the port head and the solenoid, and is sealed along its peripheral edge. A spring-biased valve rod is coupled to the opposite side of the diaphragm relative to the valve seat, and the solenoid is actuated to move the valve rod and diaphragm between open and closed positions. The valve assembly is opened by actuating the solenoid to drive the valve rod and diaphragm away from the valve seat and permit the passage of fluid across the valve seat between the inlet and outlet ports.

Abstract: An apparatus for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.