A blood clot is one of the final steps in a complex process with which the human body seals a rupture in an injured blood vessel. Clotting involves interactions between millions of blood cells, microscopic cell fragments called platelets, and various proteins. First, platelets rush to the site of injury and join together with an inner layer of fibrin and collagen proteins to form a sticky web around the break. Red blood cells are then trapped in the web, forming a clot. In certain cases a clot can block arteries and vessels that feed the brain or heart, impeding blood flow and eventually contributing to a stroke or heart attack.
Creating accurate, real-time computer simulations of how blood clots work—and the role they play in medical emergencies—could, in the future, dramatically improve the way that doctors predict the risk of damaging clots and treat the damage incurred by strokes and heart attacks. The models could, for example, help doctors position a stent—a tube placed in a blood vessel to help keep it open—before a risky surgery or offer a new way to test the effects of drugs on the circulatory system. In order to be truly accurate and useful, however, such simulations would have to account for billions of tiny cellular machines, all moving through the blood—something that has never been comprehensively modeled before.
