James R. Parker

Overview of a novel point of care instrument system for measuring whole blood Prothrombin time

This paper describes a new diagnostic instrument which uses magnetic modulation of an optical signal to rapidly measure whole blood Prothrombin time. The new instrument improves diagnosing and level monitoring by allowing accurate, rapid, low cost near patient testing. The measurement system consists of five major components: a control system; a user interface, a disposable-strip laminate architecture with proprietary chemistry which interacts with a time-varying magnetic field and accelerates the coagulation reaction; an optical measurement module -- the optics assembly of the instrument contains a heater, electromagnet, dc magnet, and numerous reflective/transmissive radiometric sensor systems; and a calibration-instrument using a custom developed test device which accurately simulates the coagulation reactions induced optical properties. The theory of operation of the coagulation assay system and optical measurement module is describe and typical data and performance metrics are presented. 6