The currently available point-of-care hemostasis tests are burdened by criticisms concerning the use of different activators and inhibitors and the lack of dynamic flow. These operating conditions may constitute an impediment to the determination of the patient’s hemostatic condition. Hence, the diffusion of these tests in clinical practice is still limited to specific scenarios. In this work, we present a new method for analyzing the patient’s global hemostasis based on the visualization of the main components of the coagulation process and its computerized quantitative image analysis. The automated “Smart Clot” point-of-care system presents a micro-fluidic chamber in which whole blood flows, without the addition of any activator or inhibitor. In this micro-channel, platelet adhesion, activation and aggregation to the type I collagen-coated surface take place (primary hemostasis), leading to the production of endogenous thrombin on the surface of platelet aggregates and the consequent fibrin mesh and thrombus formation (secondary hemostasis). These observations are verified by inhibiting primary hemostasis with the antiplatelet drugs Indomethacin (−70% on platelet aggregation, −60% on fibrin(ogen) formation) and Tirofiban (complete inhibition of platelet aggregation and fibrin(ogen) formation) and secondary hemostasis with the antithrombin drugs Heparin (−70% on platelet aggregation, −80% on fibrin(ogen) formation) and Lepirudin (−80% on platelet aggregation, −90% on fibrin(ogen) formation). Smart Clot, through a single test, provides quantitative results concerning platelet aggregation and fibrin formation and is suitable for undergoing comparative studies with other coagulation point-of-care devices.
Hemostasis depends on the coordinated interaction between platelets, coagulation factors, endothelium, and shear forces. Current point-of-care (POC) assays evaluate isolated components of haemostasis or operate under nearly static conditions, limiting their ability to reproduce physiological thrombus formation. In this study, we performed the technical validation of Smart Clot, a fully automated, microfluidic POC platform that quantifies platelet aggregation, fibrin formation, and total thrombus growth under controlled arterial shear using unmodified whole blood. Recalcified citrated blood was perfused over collagen at w = 300 s−1. Dual-channel epifluorescence microscopy acquired platelet and fibrin(ogen) signals at 1 frame per second. Integrated Density time-series were fitted with a five-parameter logistic model; first derivatives and their integrals yielded standardized pseudo-volumes for platelets, fibrin(ogen), and total thrombus. Sixty-two healthy donors established reference distributions; one-hundred-thirteen patients on antithrombotic therapy assessed pharmacodynamic sensitivity. Platelet-derived parameters were approximately normally distributed, whereas fibrin(ogen) and total thrombus values followed log-normal patterns. Anticoagulants and antiplatelet agents produced graded, mechanism-consistent inhibition of all thrombus components. Cardiopulmonary bypass samples showed profound but transient suppression of platelet and fibrin activity. Across activity ranges, multiple statistical assessments supported high analytical repeatability. Smart Clot provides rapid, reproducible, flow-aware quantification of platelet–fibrin dynamics, capturing pharmacological modulation and peri-operative impairment with high sensitivity. These results support its potential as a next-generation POC assay for physiological hemostasis assessment.
Hemostasis depends on the coordinated interaction between platelets, coagulation factors, endothelium and shear forces. Current point-of-care (POC) assays evaluate isolated components of haemostasis or operate under nearly static conditions, limiting their ability to reproduce physiological thrombus formation. In this study, we performed the technical validation of Smart Clot, a fully automated, microfluidic POC platform that quantifies platelet aggregation, fibrin formation, and total thrombus growth under controlled arterial shear using unmodified whole blood. Recalcified citrated blood was perfused over collagen at \( \dot{\gamma} \)w = 300 s⁻¹. Dual-channel epifluorescence microscopy acquired platelet and fibrin(ogen) signals at 1 frame per second. Integrated Density time-series were fitted with a five-parameter logistic model; first derivatives and their integrals yielded standardized pseudo-volumes for platelets, fibrin, and total thrombus. Sixty-two healthy donors established reference distributions; one-hundred-thirteen patients on antithrombotic therapy assessed pharmacodynamic sensitivity. Platelets-derived parameters were approximately normally distributed, whereas fibrin(ogen) and total-thrombus values followed log-normal patterns. Anticoagulants and antiplatelet agents produced graded, mechanism-consistent inhibition of all thrombus components. Cardiopulmonary-bypass samples showed profound but transient suppression of platelet and fibrin activity. Across activity ranges, multiple statistical assessments supported high analytical repeatability. Smart Clot provides rapid, reproducible, flow-aware quantification of platelet–fibrin dynamics, capturing pharmacological modulation and peri-operative impairment with high sensitivity. These results support its potential as a next-generation POC assay for physiological hemostasis assessment.