Flow detection apparatus and method

摘要

Fluid sample tester assembly (12) comprises a cartridge (6) having a pressure chamber (22) and entrance port (20) connected by a passageway (24). An analyte reagent (36) is positioned along the fluid passageway so that when a liquid sample (28) is drawn through the entrance port into the passageway, the analyte reagent mixes with the sample. The sample is preferably drawn into the cartridge by temporarily reducing the volume of the pressure chamber, applying the sample to the entrance port and then returning the pressure chamber to its initial volume; this can also be done by heating the chamber, contacting the sample and then cooling the chamber. The end of the sample defines a boundary surface (30) along the fluid passageway. Positive and negative pressure is applied to the sample to cause the boundary surface to oscillate within the passageway. The position of the boundary surface is continuously monitored so that continuous boundary position data is obtained and is analyzed to obtain a flow-related characteristic, typically speed of coagulation, of the sample.