A PIEZOELECTRIC QUARTZ-CRYSTAL SENSOR FOR THE DETERMINATION OF COAGULATION TIME IN PLASMA AND WHOLE-BLOOD

A Piezoelectric Quartz Crystal (PQC) system possessing an adequate sen sitivity to a slight viscosity change is employed to monitor the blood coagulation. In the case of an anticoagulated plasma specimen, prothr ombin time (PT) was determined by the PQC sensor on the basis of the i ntroduction of tissue thromboplastin (TF) and calcium ion. Discussing the PQC data statistically, we found that at 90% of the total frequenc y shift (Delta f) the best linear relationship in a double-logarithmic plot of PT versus TF concentration in the range of 5.466 similar to 2 2.311 unit/ml is shown. The PQC result was compared with commercial op tical coagulometry and showed a good linear correlation (ca. 0.98). Th e clotting and recalcification of whole blood were also studied by the PQC system. The testing time for one measurement could be completed w ithin 20 min. and had a good agreement with that obtained conventional ly. (C) 1998 Elsevier Science S.A. All rights reserved.