Patent ID: 6955920

Claim:
A method for determining platelet functionality of a blood sample using a plunger sensor apparatus comprising two or more test cells and a plunger assembly within each test cell, the method comprising: (a) dispensing an aliquot of said sample into each of said test cells; (b) adding a selected amount of a platelet activating reagent to all but one of said aliquot samples to form a reaction mixture; (c) adding a sufficient amount of a clotting reagent to each of said reaction mixtures to promote clotting of said aliquot samples; (d) performing a clotting test on said aliquot samples by alternately lifting the plunger assembly in each cell and allowing the plunger assembly to descend through the test mixture, wherein all of said plunger assemblies are lifted in unison; and (e) determining said platelet functionality of said sample by comparing the clotting times of said aliquot samples, wherein said clotting time of each aliquot sample is determined by measuring a change in viscosity of each of said aliquot samples.