Blood Clotting by Low-Temperature Air Plasma

In this paper, the feasibility and effectiveness of using an air-plasma torch to clot blood are studied. The emission spectroscopy and temperature measurement of the torch show that the torch produces abundant atomic oxygen in the plasma effluent. Anticoagulated whole-blood samples (10 mu l) were tested for two cases: 1) sample exposed to the plasma effluent and 2) sample exposed to a heated airflow; in both cases, the increase of the sample temperature was controlled to be about the same. No indication of blood coagulation was observed in the second case; on the other hand, in the first case when the blood sample was exposed directly to the plasma effluent, a shell was formed on the surface of the blood sample. The experimental results demonstrated that this plasma torch could clot a blood sample via a nonthermal mechanism. The dependence of the degree of blood clotting on the atomic-oxygen flux was demonstrated by varying the exposure distance. Experimental results also showed that blood coagulation was seen in the treated platelet-rich plasma sample but not in the treated platelet-poor plasma sample. Moreover, plasma treatment with multiple short exposures was shown as more effective in clotting blood than that of applying a continuous exposure with the same total exposure time.