Blood Coagulation: Plasma Torch
BySpencer P. Kuo
Pages 7

Although the term “torch” suggests high temperatures, the subject of this entry is a low temperature application—rapid stopping of the bleeding of wounds. The design of a handheld low-temperature air plasma spray is presented. A ring magnet is used to rotate a periodic arc discharge, which sprays outward by an air flow to form a nonthermal plasma torch. The image of the plasma plume and the spatial distribution of 777.4 nm radiation intensity from the emission spectroscopy of the plasma plume indicates that the plasma plume carrying abundant reactive atomic oxygen (RAO) extends outward from the torch cap by about 25 mm. Tests on blood droplets were performed. It is shown that the degree of blood clotting increases, as the plasma treatment time increases and also as the distance from the torch cap decreases, demonstrating its strong dependence on the amount of RAO delivered by the plasma plume in the plasma treatment. Through tests on smeared blood samples, a correlation between the platelet count and the clotting time was established. As animal models, pigs were used in the tests of stopping wound bleeding by this air plasma spray. The tests showed that bleedings from different wound sites—from a crosscut in the ham area, and from a hole in a saphenous vein, and from a cut to an artery in an ear—were all stopped swiftly. A blood coagulation mechanism of plasma is discussed.