A pipetting apparatus has a fluidic space to which a pressure transducer with a pressure sensor is attached with a gas filled space. The fluidic space is defined by a pipette tip, a first tubing that connects the pipette tip to a pump, and an active part of the pump. The pipetting apparatus further has an impulse generating mechanism that is in operative contact with a column of system liquid inside the fluidic space. The impulse generating mechanism induces a vertical movement in the system liquid column, which results in a pressure variation in the gas filled space that is pneumatically connected with the fluidic space. This pressure variation, as recorded with the pressure transducer and as processed by a first data processing unit during utilization of this pipetting apparatus, is taken as an indicator for the detection of penetration or of quitting of a surface of a liquid, with an orifice of the pipette tip, of which liquid an amount is to be aspirated and dispensed. This pressure variation is also taken as an indicator for the detection of the presence or the absence of gas bubbles in the system liquid contained in the fluidic space of this pipetting apparatus.

Pipetting apparatus with integrated liquid level and/or gas bubble detection

High pressure capillary liquid chromatography solvent delivery is effected at substantially low volume and atmospheric pressure. The low volume solvent composition is subsequently pressurized and expelled at high pressure into a receiving device such as a column. The solvent composition is expelled from a fluid metering system configured to deliver liquids at low pressures to a storage matrix via an isolation valve. The solvent composition is delivered to the storage matrix in reverse order such that the first volume of liquid delivered into the storage matrix is the last volume of liquid expelled out. Liquid pre-existing within the storage matrix is transferred into a fluid accumulator in fluid communication with the storage matrix. The fluid accumulator is enveloped in a pressure caisson which can be pressurized or depressurized in response to sensor signals obtained from a fluid volume displacement transducer and a pressure sensor, in accordance with solvent composition cycle formation. As the caisson is pressurized, the pressure acting on the fluid accumulator causes the solvent composition within the storage matrix to be expelled out past the isolation valve into a chromatographic column.

High pressure capillary liquid chromatography solvent delivery system

A dispensing unit for a fluid dispensing machine comprises at least an inlet duct (35) and an outlet duct (36) for fluid products, connected to a variable-volume pumping chamber (30) comprising at least one flexible wall (30a). Two non return valves mounted in counter-phase are located in the inlet and outlet ducts (35, 36), respectively. The pumping chamber is coupled to actuator means comprising a stepper motor (20) a screw-nut screw unit and a carriage (28). The carriage moves the pumping chamber from a zero position in which the chamber has a maximum volume to an upper limit in which the chamber has a minimum volume. An optic sensor (40) defines the zero point of the pumping chamber (30) so as to guarantee precision and repeatability of the dispensing operations.

Dispensing unit for a fluid dispensing machine, comprising a variable-volume pumping chamber, and machine comprising said dispensing unit

The invention relates to a pipetting apparatus ( 1 ) having a pipette tip ( 2 ) for aspirating and dispensing liquid samples; a pump ( 4 ) for generating negative pressure or positive pressure in the pipette tip ( 2 ) that is connected to the pipette tip ( 2 ) by means of a pump conduit ( 3 ); a fluid chamber ( 5 ) defined by the pipette tip ( 2 ) and/or the pump conduit ( 3 ); a measurement probe ( 6 ) functionally connected to the fluid chamber ( 5 ) for measuring the physical parameters resulting in this fluid chamber ( 5 ) during pipetting; and a device control system ( 7 ) with a processor ( 8 ), in which an activated computer program product enables the control system ( 7 ) of the pipetting apparatus ( 1 ) to individually accept or reject pipetted liquid samples on the basis of the physical parameters measured. The pipetting apparatus ( 1 ) in accordance with the invention is characterized in that it comprises a data storage device ( 9 ) for storing an actual measured curve ( 41 ) measured during pipetting and a simulated curve ( 42 ) for such a pipetting procedure and also a computer program product that in an activated state enables the processor ( 8 ) of this pipetting apparatus ( 1 ) to generate this simulated curve ( 42 ) and approximate it to the actual measured curve ( 41 ) iteratively to create an iterative curve ( 43 ) and then matching the pipetting and/or the corresponding pipetted liquid samples to one of a plurality of decision-making criteria on the basis of sections of the measured curve ( 44 ) in the actual measured curve ( 41 ) that deviate from defined threshold values ( 45 ) in relation to the corresponding sections of the curve ( 46 ) of the iterative curve ( 43 ). A corresponding computer program product and method are included within the scope of the invention.

Pipetting apparatus with a computer program product and a method for accepting or rejecting pipetted liquid samples

Apparatus for the delivery of fluid products comprising at least a base support (20), a plurality of dispensing units (13) of said fluid products contained in containing receptacles (15) by means of respective dispensing nozzles (49, 49a), wherein said dispensing units (13) are disposed on a platform (12) selectively rotatable with respect to said base support (20), in order to dispose at least one of said dispensing units (13) in at least a first position in which said fluid products are suitable to be delivered from said containing receptacles (15) to a container (17) associated with said base support (20), by means of a corresponding pumping device (45), and wherein at least a drive member (43) is disposed on said base support (20) and is suitable to be kinematically connected to one or more pumping devices (45), first rapid connection means (81, 82; 65, 66) are provided to achieve at least one of either the connection of at least one of said dispensing nozzles (49, 49a) with at least one of said dispensing units (13), or the connection between first kinematic connection means (63) suitable to be selectively connected to said drive member (43) and second kinematic connection means (48) connected to said pumping device (45).

Apparatus for the delivery of fluid products

The invention relates to a method and equipment for quantitatively dosing small amounts of liquid, especially in clinical or other similar wet-chemical analyzers. The dosing employs a liquid space, the volume of which can be changed and which is connected to a dosing channel so that, by increasing or decreasing the volume of the liquid space, a suction or an injection through the dosing channel is achieved. The liquid space is formed by flexible bellows which are freely movable back and forth to provide the reversible deformations which change the volume of the liquid space. The movements are effected using an actuator which is connected to the bellows without transmissions containing sliding surfaces. The actuator comprises precisely repeatable positions and is calibrated according to the invention by measuring the sizes of the dosages produced by the movements between the positions. The dosing is effected after that by selectively repealing the calibrated movements. The actuator can be formed by a stepper motor, and a cam shaft rotated by the stepper motor propelling the bellows back and forth. The nonlinear interdependent relationship between the rotation of the shaft and the change in the volume of the liquid space makes possible a wide range of calibrated dosage sizes.

Pertti Tuominen

Papers

Method and equipment for dosing small amounts of liquid quantitatively