20.500.12556/DiRROS-21916 Elucidating the mechanisms of microbubble formation in intracardiac pulsed field ablation Delivery of electrical energy for sensing or therapeutic purposes often involves electrochemical phenomena at the electrode-electrolyte solution interface. Release of gaseous bubbles that accompanies delivery of pulsed electric fields to tissues in applications such as electrochemotherapy of tumours and irreversible electroporation or pulsed field ablation in cardiac electrophysiology needs to be understood and characterized. We present an in vitro study using pulsed field delivery into saline, employing multiple different treatment protocols, two electrode geometries (pair of needles and a modified RF catheter), and two imaging systems to elucidate the complex relationship between the electrical treatment protocol, temperature changes at and around the electrodes, and gas release due to pulse delivery. Our primary objective was to identify the key parameters responsible for bubble formation and to highlight the importance of the treatment parameters and their interplay – ranging from the temperature to appropriate choice of electrode geometry, and, most importantly, to the choice of the treatment protocol. We found that bubbles originating from electrochemical reactions are more prevalent in monophasic pulsing protocols, whereas in high frequency biphasic pulsing protocols the bubbles are mainly caused by boiling of the medium. Degassing of liquid due to lower solubility of gasses at elevated temperatures does seems to play a role, though a minor one. We also observed that bubbles caused by boiling collapse very rapidly, whereas electrochemically produced bubbles or those produced through degassing appear to have longer lifetimes. Therefore, the treatment protocols most suited to minimizing gas release are biphasic trains of short (▫$\mu$▫s) pulses with a significant inter-pulse delay (i.e. low duty cycle) to prevent excessive heating. Moreover, electrodes must be designed to avoid high local current densities. Our findings have broad implications extending from lab-on-achip cell electroporation devices to intracorporeal pulsed field applications in the cardiovascular system, particularly pulsed field ablation procedures. pulsed field ablation gas release electrochemistry Joule heating water phase transition ablacija s pulznim električnim poljem sproščanje plina elektrokemija Joulovo segrevanje fazni prehod vode true false true Elsevier Nizozemska Angleški jezik Slovenski jezik © 2024 The Authors. Neznano 2025-04-10 14:06:43 2025-04-10 14:06:43 2025-10-24 03:50:10 0000-00-00 00:00:00 2024 0 0 Nasl. z nasl. zaslona; Opis vira z dne 1. 7. 2024; 12 str. [article no.] ǂ144550 Vol. 497 1 Sep. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2024-01-15 2024-06-06 2024-06-07 602.621:544.6:616-089.87 1873-3859 10.1016/j.electacta.2024.144550 200309251 https://www.sciencedirect.com/science/article/pii/S0013468624007904 1 45b2ff15-1604-11f0-963a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=31615 RAZ_Mahnic-Kalamiza_Samo_2024.pdf RAZ_Mahnic-Kalamiza_Samo_2024.pdf 1 E2565CAFD5F04E67D6B2340B0590894F 1bac9093a345f0ca9009907e20a57cc194583c7e362ae5e12b5a95b1e73e4ea1 a775f976-1604-11f0-963a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=31616 Institut Jožef Stefan 0 0 0