Abstract: A measured amount of a first fluid is metered into a measured amount of a second fluid by a method where a fluid is confined within a first chamber and a plunger of predetermined volume is mechanically moved into the chamber to displace a first measured amount of fluid after which a second plunger is mechanically moved into a defined volume of the chamber to displace a second volume of fluid therefrom different from the first volume whereupon the first and second volumes can be mixed in predetermined proportions.

Abstract: A method and apparatus for analyzing a sample to determine an analyte content has a sensor for sensing the analyte positioned between a first and second transducer. The analyte or derivatives thereof are reciprocated between the first and second transducer to reciprocate at the sensor and allow instantaneous sensing of an indication of the analyte's presence at a point between the first and second transducer. Rapid analysis can be carried out in many different systems including for example where the transducers are enzyme reactors and the analytes are body metabolites.

Abstract: A multi-mode, differential fluid displacement pump provides for at least two different measured doses. The pump has a chamber in which are mounted a first diameter piston and a second diameter piston defining first and second volumes for reciprocation in the chamber. Means are provided for reciprocating the pistons as desired to obtain predetermined volume changes corresponding to movement of either or both of the first and second pistons. A system of operation and a mixing chamber useful in connection with dosages from the pump are interconnected with the pump.

Abstract: Rapid and accurate whole blood analysis measurements are made with analysis systems of the potentiometric type that employ restricted diffusion type liquid junctions where the whole blood sample is flowed past sensing electrode and liquid junction at a velocity of at least one centimeter per second during a data acquisition interval that is at least twenty-five milliseconds in duration.

Abstract: A reference liquid system for use with a chemical analyzer that has a plurality of ion selective electrodes comprises a plurality of reference liquids, each of which has a first salt component such that ions of a first element to be measured are present in a predetermined concentration, a second salt component such that ions of a second element to be measured are present in a predetermined concentration, and an error compensation salt component present in a concentration effective to adjust(a) the activity coefficient factor and/or(b) the junction potential factorto reduce the error involved in use of the compensated reference liquid to less than fifty percent of the error involved in use of a corresponding uncompensated reference liquid.

Abstract: A clinical analyzer system flows a small volume (less than 200 microliters) of liquid sample to be analyzed from an inlet port past a sensor array to a series of analysis chambers. The sensor array includes two optical sensor units that are spaced a fixed distance apart, and each sensor unit transmits a beam of infrared radiation through the flow tube for sensing by a detector. Each detector output has a low value when blood is in the flow tube, an intermediate value when air is in the flow tube, and a high value when a clear liquid is in the flow tube. Control logic senses changes in the outputs of the detectors and accurately indicates gas-liquid interface transitions. The noninvasive system accurately locates leading and trailing edges of samples of biological fluids to be analyzed, monitors the integrity of those samples, and distinguishes between types of sample liquids processed by the analyzer.

Abstract: A system for analyzing a biological fluid specimen or the like includes an analysis chamber and an electrochemical electrode measuring system connected in sensing relation to the analysis chamber. A flow network connects a sample inlet port and an auxiliary fluid reservoir to the analysis chamber. The flow network includes a sample line connected between the sample inlet port and the analysis chamber and an auxiliary manifold connected to the auxiliary fluid reservoir. A positive displacement pump is connected in the sample line between the analysis chamber and a waste outlet port.