coagulometers

Coagulometers are laboratory instruments that measure the clotting properties of blood by detecting the formation of a clot in a sample, usually plasma or whole blood. They are used to evaluate coagulation pathways, monitor anticoagulant therapy, screen for bleeding disorders, and support surgery and transfusion decisions.

Most coagulometers detect changes that accompany clot formation using distinct approaches. Mechanical coagulometers monitor movement or viscosity changes as a clot forms. Optical coagulometers measure changes in turbidity or optical density. Viscoelastic devices, such as thromboelastography or rotational thromboelastometry, assess the evolving viscoelastic properties of clot formation in real time and provide parameters on clot strength and stability.

Common tests performed include prothrombin time with international normalized ratio (PT/INR) and activated partial thromboplastin time (aPTT); some systems also report thrombin time, fibrinogen estimation, or provide viscoelastic profiles for entire coagulation processes.

Coagulometers are used in hospital laboratories and some point-of-care settings. Results are generated in seconds to minutes and are interpreted with reference ranges or control materials. Quality control, calibration, and reagent management are essential to ensure accuracy and comparability across instruments. Pre-analytical variables such as sample collection, anticoagulant type, and storage conditions can affect results.