CLOTTOCYTES - ARTIFICIAL MECHANICAL PLATELETS:
SPECIALIZED NANOROBOTS TO STOP BLEEDING
SPECIALIZED NANOBOTS TO STOP BLEEDINGPlatelets - or thrombocytes - are irregular, roughly spheroidal, 2 micron diameter, anuclear (nucleus-free) blood cells that have an average lifespan of just 5-9 days. Platelets circulate in our bloodstreams and are integral in achieving hemostasis (stoppage of blood flow) after injury. An average, healthy person has between 150,000 and 450,000 platelets per μl (microlitre) of blood. In the event of an injury, platelets gather at the site and activate, becoming sticky and clumping together to form a barrier to seal the damaged blood vessel and stop the bleeding. Platelets are also responsible for releasing clotting factors. The image shows a comparison, from left to right, of a red blood cell, an activated platelet, and a white blood cell. Nature's solution can be quite effective, but it does take valuable time.
The clottocyte is a, yet theoretical, design by Robert A. Freitas Jr. for an artificial, mechanical platelet. The response time of a clottocyte would be on the order of 100-1000 times quicker than nature's platelets, achieving complete hemostasis in as short as one second. Clottocytes would have several distinct advantages over their natural counterparts. For instance platelet function can be adversely affected by drugs such as aspirin. Clottocytes would be immune to the effects of drugs, and could function optimally irregardless of chemical fluctuations in the bloodstream.
Clottocytes represent an example of a uniquely nanotechnological benefit that could not - even in principle - be achieved by biotechnology. Clottocytes could potentially be on the order of 10,000 times more effective at achieving clotting, by volume, than natural platelets, therefore being required at only ~0.01% of the concentration of platelets in the bloodstream. Clottocytes would be approximately 2 micron diameter spherical nanorobots, powered by serum oxyglucose, and controlled by an onboard nanocomputer. They would contain a compactly folded fiber mesh which could be unfurled in the immediate vicinity of a damaged blood vessel. The overlapping nettings deployed by activated clottocytes would trap blood cells and halt bleeding almost instantaneously.