@inproceedings{StelzerTauwaldVielsmeieretal., author = {Stelzer, Vera and Tauwald, Sandra Melina and Vielsmeier, Veronika and Cieplik, Fabian and Kandulski, Arne and Schneider-Brachert, Wulf and W{\"u}nsch, Olaf and R{\"u}tten, Markus and Krenkel, Lars}, title = {Generation and Distribution of Surgical Smoke During High Frequency Electrocauterization}, series = {New Results in Numerical and Experimental Fluid Mechanics XIV. STAB/DGLR Symposium 2022}, booktitle = {New Results in Numerical and Experimental Fluid Mechanics XIV. STAB/DGLR Symposium 2022}, editor = {Dillman, Andreas and Heller, Gerd and Kraemer, Ewald and Wagner, Claus and Weiss, Julien}, publisher = {Springer Nature Switzerland AG}, address = {Cham, Switzerland}, isbn = {978-3-031-40481-8}, doi = {10.1007/978-3-031-40482-5_53}, pages = {559 -- 568}, abstract = {Surgical Smoke is generated during the cauterization of tissue with high-frequency (HF) devices and consists of 95\% water vapor and 5\% cellular debris. When the coagulation tweezers, which are supplied with HF voltage by the HF device, touch tissue, the electric circuit is closed, and smoke is generated by the heat. In-vivo investigations are performed during tracheotomies where surgical smoke is produced during coagulation of tissue. Furthermore, in-vitro parametric studies to investigate the particle number and size distribution and the spatial distribution of surgical smoke with laser light sheet technique are conducted. With higher power of the HF device, the particles generated are larger in size and the total number of particles generated is also higher. Adding artificial saliva to the tissue shows even higher particle counts. The study by laser light sheet also confirms this. The resulting characteristic size distribution, which may include viruses and bacterial components, confirms considering the risk arising from surgical smoke. Furthermore, the experiments will provide the database for further numerical investigations.}, language = {en} } @misc{KrenkelMichelKeiletal., author = {Krenkel, Lars and Michel, Johanna and Keil, Niklas and Daschner, Jan}, title = {Experimental Investigation of Logitudinal Folds in Endotracheal Tube Cuffs and their Correlation to Silent Breathing}, series = {23. DGLR Fach-Symposium Str{\"o}mungen mit Abl{\"o}sung, 09./10. November 2022, Berlin, Deutschland}, journal = {23. DGLR Fach-Symposium Str{\"o}mungen mit Abl{\"o}sung, 09./10. November 2022, Berlin, Deutschland}, address = {G{\"o}ttingen}, organization = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt e.V. / Arbeitsgemeinschaft Str{\"o}mungen mit Abl{\"o}sung, AG STAB}, abstract = {Air leakage past High-Volume-Low-Pressure (HVLP) endotracheal tube (ETT) cuffs creates a potential infection risk for health care professionals during ventilation of patients suffering from contagious airborne diseases. However, unlike silent aspiration, a phenomenon where fluids enter the airways of intubated patients, the aspect of aerosol emergence through cuff folds -what we called accordingly "silent breathing" (SB)- has not been investigated in detail so far. This study investigates air leakage past HVLP cuffs with varying cuff pressures under realistic artificial breathing scenarios experimentally and in addition numerically. The focus was laid on the parametric investigation of the occurrence and furthermore on different influencing factors of silent breathing. The morphology of the folds responsible for the leakage was captured using high-resolution 3D microcomputed tomography (μCT). For the numerical investigations (Com-putational Fluid Dynamics - CFD), the commercial CFD Software package FLUENT 2021 R2 (ANSYS, Inc., Canonsburg, PA, US), as well as the DLR in-house research code THETA has been used.}, language = {en} }