Whole blood is incubated at 37°C in a heated cup in which a suspended pin is connected to a detector system (a torsion wire in TEG and an optical detector in ROTEM). The cup and pin are oscillated relative to each other through an angle of 4° 45′. The movement is initiated from either the cup (TEG) or the pin (ROTEM). As fibrin strands forms between the cup and pin, the transmitted rotation from the cup to pin (TEG) or the impedance of the rotation of the pin (ROTEM) are detected at the pin, and a trace is generated. The trace is divided into parts that reflect different stages of the hemostatic process (clotting time, kinetics, strength, and lysis) with slightly different nomenclature for TEG and ROTEM.²²  TEG and ROTEM parameters in the different phases of clot initiation, amplification, propagation, and degradation. TEG: R, reaction time (minutes); angle (degrees); MA, maximum amplitude (mm); Ly30, amplitude reduction after 30 minutes as an indicator of hyperfibrinolysis (%). ROTEM: CT, clotting time (seconds); A10, amplitude after 10 minutes (mm); MCF, maximum clot firmness (mm); Li30, amplitude reduction after 30 minutes as an indicator of hyperfibrinolysis (%). TEG functional fibrinogen maximal amplitude (mm). ROTEM FIBTEM (mm).