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Heat transfer simulation for design of electrothermal bipolar vessel sealing device

For the design of an electrothermal bipolar vessel sealing device, the consideration of thermal damage to the vessel is important. To design a radio frequency (RF) electrode that imparts minimal thermal damage to the tissue, we proposed four different types of RF electrode arrangements. We also simulated the temperature distribution in each type of arrangement using an analysis program. We assumed the material of the RF electrodes to be heat-resistant stainless steel alloy 321 and defined the heat transfer parameters of the blood vessel. A volume-type heat source was set to constantly generate 5 W of heat in a period of 10 s. We did not consider the conditions of the blood vessel, such as humidity at the contact surface, effect of the surrounding tissues, and blood flow, for the purpose of simplifying the model under simulation. The maximum temperature of the blood vessel in each case was similar but the temperature distribution was different depending on the shapes of the RF electrodes. We identified the best operation time for maintaining the temperature under 50 °C, the threshold for minimal thermal damage to the tissue. Using the results of this study, we will be able to obtain the appropriate operation time and a more suitable design for the RF electrode.