The ROTEM sigma thromboelastometry system is a fully integrated and automated in vitro diagnostic system designed to monitor and analyze a patient’s coagulation status by measuring the viscoelastic properties of a 3.2% citrated venous or arterial whole blood sample. The ROTEM sigma system is indicated for use with adult patients 21 years and older where a semi-quantitative evaluation of their blood coagulation properties is desired, in the point of care and laboratory settings. Coagulation evaluations on the ROTEM sigma instrument, together with the ROTEM sigma complete + hep cartridge, are used to assess peri-operative hemorrhage and/or thrombosis in cardiovascular surgery.