Self-powered disposable prothrombin time measurement device with an integrated effervescent pump

Coagulation is an essential physiological activity initiated by the interaction of blood components for clot formation. Prothrombin time (PT) measurement is a clinical test for the assessment of the extrinsic/common pathways of coagulation cascade. Periodic measurement of PT is required under numerous conditions including cardiovascular disorders. We present a self-powered microfluidic device for quantitative PT measurement from 50 μl whole blood. The entire platform is disposable and does not require any external pumping, power, or readout units. It consists of a 3D-printed effervescent pump for CO2 generation from a chemical reaction, a cartridge for two-channel fluid flow (blood and water), and a grid for the quantification of fluid migration distance. Following the introduction of the fluids to the corresponding channel inlets, marking the coagulation start, an acid-base reaction is triggered for gas generation that drives the fluids within the channels. When the blood coagulates, its flow in the channel is halted. At that point, the distance water has travelled is measured using the grid. This distance correlates with PT as demonstrated through clinical tests with patient samples. This single-unit device has a potential for rapid evaluation and periodic monitoring of PT in the clinical settings and at the point-of-care.