Toward Diagnosis of Platelet Loss in Trauma Injury Using a Microfluidic Dielectric Sensor

This paper reports on capturing the morphological changes in red blood cells (RBCs) during platelet-driven blood clot retraction using a microfluidic dielectric sensor, termed ClotChip. The sensor is based on the technique of dielectric spectroscopy and incorporates screen-printed, gold, sensing and floating electrodes embedded into a microfluidic channel with a total sample volume of < 10μL to form a 3D, parallel-plate, capacitive sensing area. The ClotChip readout parameter, Δεr,max, is shown to be sensitive to the degree of deformation in the shape of RBCs caused by either impairing the contractile forces acting on the RBCs via a depletion of activated platelets or altering their membrane rigidity. Furthermore, a baseline range for Δεr,max parameter is established using 95 healthy whole blood samples, and the ClotChip is shown to detect weak clot formation, when the platelet count drops below 15,000 per μL. This work highlights the potential of ClotChip as a platform technology for rapid assessment of platelet loss during traumatic hemorrhage at the point-of-injury.