NOVEL INSTRUMENTATION FOR REAL-TIME MONITORING USING MINIATURIZED FLOW SYSTEMS WITH INTEGRATED BIOSENSORS

A prototype miniaturized Total Chemical Analysis System (mu TAS) has b een developed and applied to on-line monitoring of glucose and lactate in the core blood of anaesthetized dogs. The system consists of a hig hly efficient microdialysis sampling interface sited in a small-scale extracorporeal shunt circuit ('MiniShunt'), a silicon machined microfl ow manifold and integrated biosensor array for glucose and lactate det ection with associated computer software for analytical process contro l. During in-vivo testing the device allowed real-time on-screen monit oring of glucose and lactate with system response times of less than 5 min, made possible by the small dead volume of the microflow system. On-line glucose and lactate measurements were made in the basal state as well as during intravenous infusion of glucose or lactate. The prot otype mu TAS is currently suitable for trend monitoring but refinement s are necessary before application of the system for determination of individual lactate values.