Design and implementation of a microchemistry analyzer

Abstract

Advancements in the microfabrication methods of silicon chips make it possible to produce biosensor arrays coated with specific ionophores or enzymes, in large volumes, with a high degree of reliability, and at a low cost. The i-STAT System incorporates such micro-arrays in a disposable cartridge, 1x1.75x0.2 in. The cartridge performs analysis on 2–3 drops of whole blood and can within 2 minutes, measure Na+, K+, Cl−, Ca++, HCO3−, Glucose, Urea, pH, pO2, pCO2, and Hct. In addition, the cartridge contains a fluid calibrant and is automatically calibrated before every patient's sample. The analyzer is fully automatic and specifically designed to assure reliable results in non-laboratory settings. The only steps required by the user are placing the blood, inserting the cartridge into the analyzer, and entering patient and operator identification numbers. Numerous automatic reliability tests are incorporated including detection of user induced errors. A unique quality control procedure is provided via an electronic simulator which tests the functionality of the analyzer at 2 levels beyond reportable ranges, and at narrow sensitivity limits. © 1996, Walter de Gruyter GmbH, Berlin/Boston. All rights reserved.