ISSN:
1741-0444
Keywords:
Blood electrolytes
;
Calcium
;
Chem FET
;
Ion-selective electrodes
;
ISFET
;
Online monitoring
;
Patient monitoring
;
pH
;
Potassium
;
Sodium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract A system for the online, simultaneous analysis of bloodK +,Ca 2+,Na + andpH using a quadruple-function ChemFET integrated circuit sensor is described. The ChemFET device is mounted into a miniature flow-through cell having a very small sample volume (ca. 30 μl), which is incorporated into a sensing unit together with a pinch-tube sampling valve, a heat exchanger and a reference electrode. The sensing unit is small and robust, with an overall input deadspace small enough (ca 460 μl) to permit connection directly to an indwelling, dual-lumen cannula for continual, intermittent sampling without causing undue exanguination; the cannula is actively heparinised to prevent clot formation in the aspirated blood samples. An analyte-chopping analysis (ACA) system is used to prevent protein contamination of the ChemFET sensor, and to ensure the high precision of measurement which is necessary for clinical applications over extended periods. The system is controlled by a microcomputer, which supervises preusage calibration, logs data, and provides graphical displays of ion concentrations. Preliminary clinical results are presented which reveal significant dynamic changes inCa 2+ due to the intraoperative transfusion of citrated blood, and substantial fluctuations in the concentration profiles ofK +,Ca 2+ andpH during cardiopulmonary bypass.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02441586
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