Quasi-static acoustic tweezing for small volume blood coagulation analysis
The activation of the coagulation cascade at artificial surfaces of container walls leads to inherent variability and unreliability in predicting bleeding or thrombosis risks. Large number of false results and a lack of standardization have caused concern in the medical community about the usefulness of photo-optical plasma coagulation tests such as PT/aPTT as well as whole blood viscoelastic methods. We have developed an integrated photo-optical / viscoelastic method for noncontact blood coagulation analysis. In this approach, referred to as “integrated quasi-static acoustic tweezing thromboelastometry” (i-QATT), temporal changes in blood elasticity and turbidity during coagulation are assessed from a single drop of blood levitating in air. i-QATT provides comprehensive information about blood coagulation including reaction time, kinetics of fibrin formation and cross-linking, clot firmness, fibrinolysis, and functional level of coagulation factors. This work demonstrates the ability of this method to rapidly and reliably measure the coagulation factor deficiency, functional levels of fibrinogen and factor XIII, platelet function, heparin dose response as well as identify bleeding / thrombotic risks in human subjects. i-QATT has been successfully used to detect the hypercoagulable state in smoking subjects.