The in vitro evaluation of platelet aggregation is useful to diagnose platelet function disorders [1, 2]; in some laboratories, the test is also used to monitor antiplatelet treatment [3]. Traditionally, platelet aggregation is measured by light transmission aggregometry (LTA), which measures the changes in transmission of a beam of light through a sample of platelet-rich plasma (PRP) or platelet suspensions in buffer, which occur when platelets change shape and aggregate upon stimulation. As this technique has some disadvantages [2], novel methods were introduced to measure platelet aggregation in vitro.