AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Evaluation of the Size Distribution and Morphology of Submicrometer Particles Generated from Electrosurgical Tools
YUECHEN QIAO, Austin Andrews, Chase Christen, Brian MacLachlan, Samir Khariwala, Bernard Olson, Christopher Hogan Jr., University of Minnesota
Abstract Number: 56 Working Group: Aerosol Exposure
Abstract Electrosurgical pencils (EPs) are widely used in a variety of medical procedures to aid in surgical cutting and cell and tissue coagulation. EPs are known to generate “surgical smoke”, i.e. their use leads to the formation of a visible aerosol. The likely mechanism of aerosol formation is evaporation of organic material due to heating of tissue, followed by incomplete oxidation of this material in the gas phase, yielding particles. Therefore, the aerosol formation process may be similar to biomass burning and combustion processes, and may yield particles of similar size distribution and morphology to combustion systems. We examined the size distribution and morphology of particles produced by the operation of a monopolar EP applied to fresh bovine shoulder tissue at variable power settings. Measurements were carried out using (1) a differential mobility analyzer (DMA) and condensation particle counter (CPC) to determine mobility distribution functions in the 10 nm – 400 nm size range, (2) an aerodynamic particle sizer (APS) to determine aerodynamic particle size distributions in the 0.3 μm – 20 μm size range, (3) a DMA-electrostatic sampler to examine particle morphology at selected mobility equivalent sizes, and (4) a DMA- aerosol particle mass analyzer (APM) to determine the effective densities and mass-mobility scaling for particles. Collectively, measurements show a single mode, broad size distribution function of particles is produced in the 50 nm – 2 μm mobility diameter range, with a mode in the 100 nm – 200 nm range. Microscope analysis of particles revealed that spherical particles, fractal-like aggregates, and faceted, cubic particles can be produced simultaneously. Aggregate formation was confirmed through effective density determination. In total, results show that the particles produced during EP operation are morphologically extremely complex, suggesting there are multiple particle growth mechanisms occurring simultaneously, without sufficient time for internal mixing of the aerosol.