Analysis of the information content in Sonoclot data and reconstruction of coagulation test variables

The Sonoclot Coagulation Analyzer is a viscoelastometer used for in vitro analysis of the coagulation process from the start of fibrin formation, through polymerization of the fibrin monomer, platelet interaction, and eventually to clot retraction and lysis. In this paper, we have analyzed series of Sonoclot curves and simultaneously obtained coagulation tests (APT, PT, Fibrinogen, Platelet Count, and D-dimer) from patients who underwent total hip replacements (THA). By using the Principal Component Analysis method (PCA), we found that the most important coagulation test variables as reflected in the Sonoclot signature, are Platelet Count, PT, and Fibrinogen. Also, by using a Back-Propagation Neural Network (BP), we were able to reconstruct the coagulation variables Platelet Count, PT, and Fibrinogen from the Sonoclot curve with a reasonable accuracy. This would also indicate that these three coagulation test variables are most important in determining the appearance of the Sonoclot signature.