Bayer Corporation

Robert William Eherts

Paul G Gherson

Evandro S Denunzio

Theodore Pernicano

Carl R Gebauer

The sample dilution module includes an oil filled aspiration probe and mixing chamber that communicate with each other while the mixing chamber is maintained at an angle of approximately 5 to 45 degrees below a horizontal axis. The aspiration probe is maintained in a vertical orientation. A micro-bubble is aspirated between separate aspirations of test sample and diluent to prevent contact between the sample and diluent in the aspiration probe. The test sample and diluent are then drawn from the vertically oriented aspiration probe into the mixing chamber. After the sample and diluent are in the mixing chamber the micro-bubble of air can migrate away from the test sample and diluent to enable the test sample and diluent to contact each other. Mixing of the test sample and diluent is accomplished by moving the test sample and diluent back and forth in the mixing chamber without physical agitation of the mixing chamber and without any mixing element in the mixing chamber. Such movement is accomplished by alternate suction and vacuum forces imposed on the fluid in the mixing chamber.

Sample dilution module with offset mixing chamber

A blood clot detector includes a pressure transducer on an aspiration line to provide output voltage data to a microprocessor corresponding to the vacuum level during aspiration. The microprocessor integrates the vacuum readings over time during the aspiration cycle to provide a pressure integral for each test sample aspiration. A pressure integral is determined for an unclotted aspiration and used as a reference for comparison with the pressure integrals of each test sample aspiration to determine whether a blood clot has interfered with the test sample aspiration. A valve is provided across an analytical line and an aspiration line to provide selective communication between the aspiration line and the analytical line or to prevent such communication. Communication between the aspiration line and the analytical line permits transfer of a test sample from the aspiration line to the analytical line if the test sample is considered acceptable for sample analysis. Acceptability of the test sample for analysis is based upon a predetermined difference between the reference pressure integral and each test sample pressure integral.

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Middletown, NY, United States of America

Robert William Eherts