Abstract: A microfluidics device to provide real time monitoring of platelet aggregation of a biological sample obtained from a subject. The device comprises a channel configured for passage of the biological sample, the channel comprising a protrusion configured to induce an upstream region of shear acceleration coupled to a downstream region of shear deceleration and defining there-between a region of peak rate of shear, the downstream region of shear deceleration defining a zone of platelet aggregation. The device further comprises a platelet detection means for detecting aggregation of platelets in the zone of aggregation as a result of passage of the biological sample through the channel. Methods to assess real time platelet aggregation of a biological sample obtained from a subject are further described.