Bayer Corporation

Chiron Diagnostics Corporation

Jeffrey S Dorenkott

Carl F Panek

Steven E Wilder

Kurukundi Ramesh Murthy

William R Downing

Dinh Nyugen

A method and apparatus for aspirating and dispensing a sample fluid. The apparatus includes a dilutor having a port coupled to a first port of a flow through pressure transducer and to a bleed valve. A second port of the flow through pressure transducer is coupled to a first port of a sample probe. The flow through pressure transducer provides transducer signals to a detector circuit. In response to the transducer signals provided thereto, the detector detects the occurrence or non-occurrence of a plurality of different events. The dilutor is operational to aspirate and dispense fluids such as air or liquid samples in order to provide accurate aspiration and dispensation of a sample fluid. The method includes the steps of first aspirating a predetermined amount of air with the dilutor, dispensing air while moving the sample probe towards the fluid sample, measuring the pressure in the probe and using this pressure value as a baseline, monitoring the pressure and detecting when the pressure changes, which is indicative of the probe entering the fluid sample, bleeding the pressure into the atmosphere while returning the dilutor to its home position, aspirating a predetermined amount of fluid to remove dilutor backlash, waiting a predetermined amount of time to finish bleeding the system, then aspirating the fluid sample with the dilutor. With such a method and apparatus, accurate aspirations/dispensations are provided, especially when small volumes are required.

Method and apparatus for aspirating and dispensing sample fluids

A method of verifying sample volume quantifies the fluid volume aspirated and verifies sample uniformity by detecting the presence of foam or clots in the sample. After aspiration, a pressure sensor is used to measure the vacuum needed to hold up the column of fluid in the probe tip. By knowing the geometry of the probe tip, the vacuum can be converted to a sample weight and volume, based on sample densities. Non-ideal conditions, such as foam on the surface of the fluid or a clot in the fluid, result in a sample volume much lighter, in the case of foam, or much greater, in the case of a clot, than anticipated. The method also determines the elapsed time of the aspiration. Foamy samples result in aspiration times shorter than normal. Clotted samples result in aspiration times longer than normal. Additionally, a determination can be made as to whether an error condition occurred. The error condition could be the occurrence of the sample fluid container becoming substantially empty of sample fluid during aspiration or the sample probe no longer being in contact with the fluid due to the probe not following a declining fluid level as the fluid is aspirated.

Method of verifying aspirated volume in automatic diagnostic system

A nethod of verifying sample volume quantifies the fluid volume aspirated and verifies sample uniformity by detecting the presence of foam or clots in the sample. After aspiration, a pressure sensor is used to measure the vacuum needed to hold up the column of fluid in the probe tip. By knowing the geometry of the probe tip, the vacuum can be converted to a sample weight and volume, based on sample densities. Non-ideal conditions, such as foam on the surface of the fluid or a clot in the fluid, result in a sample volume much lighter in the case if foam, or much greater, in the case of a clot, than anticipated. The method also determines the elapsed time of the aspiration. Foamy samples result in aspiration times shorter than normal. Clotted samples result in aspiration times longer than normal.

A method and apparatus for aspirating and dispensing a sample fluid. The apparatus includes an air source having an output port coupled to a first port of a flow through pressure transducer. A second port of the flow through pressure transducer is coupled to a first port of a sample probe. The flow through pressure transducer provides transducer signals to a detector circuit. In response to the transducer signals provided thereto, the detector detects the occurrence or non-occurrence of a plurality of different events.

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North Olmsted, OH, United States of America

Jeffrey S Dorenkott