血栓弹力图TEG技术.doc

THE TEG? THROMBELASTOGRAPH? HEMOSTASIS ANALYZER The TEG system is comprised of an analyzer and software which together provide a complete picture of the formation and dissolution of the clot, showing the balance or imbalance of the two systems. What can TEG analysis measure? Consistent with advances in the understanding of hemostasis, TEG technology analyzes platelet function. Because the TEG analyzer monitors the elasticity of clotting blood, the system is sensitive to all the interacting cellular and plasmatic components such as coagulation and fibrinolytic factors, activators, and inhibitors that may affect the rate or structure of a clotting sample and its breakdown. The TEG analyzer measures the mechanical properties of the developing clot: ? The time until initial fibrin formation; ? The kinetics of the initial fibrin clot to reach maximum strength; and, ? The strength and stability of the fibrin clot and its ability to do the work of hemostasis, that is, to mechanically impede hemorrhage without permitting inappropriate thrombosis. THE TEG ANALYZER TECHNOLOGY The TEG analyzer has a sample cup that oscillates constantly at a set speed through an arc of 4°45. Each rotation lasts ten seconds. A whole blood sample of 360 ul is placed into the cup, and a stationary pin attached to a torsion wire is immersed into the blood. When the first fibrin forms, it begins to bind the cup and pin, causing the pin to oscillate in phase with the clot. The acceleration of the movement of the pin is a function of the kinetics of clot development. The torque of the rotating cup is transmitted to the immersed pin only after fibrin-platelet bonding has linked the cup and pin together. The strength of these fibrin-platelet bonds affects  the magnitude of the pin motion, such that strong clots move the pin directly in phase with the cup motion. Thus, the magnitude of the output is directly related to the strength of the formed clot. As the clot retracts or lyses, these bonds are b