Abstract: A coagulation test for determining the activated clotting time (ACT) of blood in the presence of heparin that produces test results that are substantially insensitive to the drug aprotinin. The activator is formulated to be a combination of celite and bentonite. The ACT results obtained with this formulation are similar to celite ACT tests on heparinized blood while simultaneously being unaffected by aprotinin. Additionally, a method for quantifying the aprotinin effect of different ACT formulations is disclosed.

Abstract: A transducer for use in a viscoelastic analyzer of the type in which a mechanical probe member is immersed in a fluid or gel and driven to impart a desired oscillating motion to such fluid or gel whose viscoelastic properties are to be determined including means for restricting motion of the probe member of the transducer in all directions except the direction of desired oscillation motion.

Abstract: A transducer for use in a viscoelastic analyzer of the type in which a mechanical probe member is immersed in a fluid or gel and driven to impart a desired oscillating motion to such fluid or gel whose viscoelastic properties are to be determined including means for restricting motion of the probe member of the transducer in all directions except the direction of desired oscillating motion.

Abstract: An instrument for testing the viscoelastic characteristics of fluids, such as blood, exhibits improved temperature regulation of the blood sample under test, includes probe drive circuitry to simplify calibration and signal conditioning, incorporates resonant frequency monitoring to detect mechanical noise disturbances, and provides automated analysis of a graphical signature, over time, of the viscoelastic characteristics of the blood sample, including a visual indication to the user of the activated clotting time period (ACT) and the rate of clot formation (RATE) of the blood sample under test, thereby improving the accuracy of the test results and simplifying operation of the instrument to permit its use by surgical personnel.

Abstract: An instrument for testing the viscoelastic characteristics of fluids, such as blood, exhibits improved temperature regulation of the blood sample under test, includes probe drive circuitry to simplify calibration and signal conditioning, incorporates resonant frequency monitoring to detect mechanical noise disturbances, and provides automated analysis of a graphical signature, over time, of the viscoelastic characteristics of the blood sample, including a visual indication to the user of the activated clotting time period (ACT) and the rate of clot formation (RATE) of the blood sample under test, thereby improving the accuracy of the test results and simplifying operation of the instrument to permit its use by surgical personnel.