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Impact of the orientation of electrodes on ire parameters

Mamundur Raman, Nivedha (2021) Impact of the orientation of electrodes on ire parameters.

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Abstract:Hepatocellular carcinoma (HCC) is one of the most common causes of cancer death worldwide. Some of the current treatment options include surgical resection, liver transplantation, thermal ablation etc. Even though surgical resection is the most preferred option, very few are amenable due to the complexities with regard to the size and location of tumors. Over the years, many minimally invasive methods such as Irreversible electroporation (IRE) has been developed to specifically destroy the undesirable tissues as an alternative to surgical resection. This reduces the treatment time and also the damage to the surrounding healthy tissues. IRE is based on exposing the cell to electric pulses which increases the permeabilization of the cell membrane leading to the formation of nanopores thereby inducing cell death. Despite the advantages of IRE, it is not considered as the best choice for the treatment of the tumors. This is because of the lack of a systemic way to obtain an optimal treatment planning due to which some tumors cannot be ablated completely which increases the risk of recurrence of the tumors. The effectiveness of the IRE is dependent on the electric field distribution in the tissue. The electric field distribution is dependent on various electrode and pulse parameters. One of the standard requirements of IRE for a uniform electric field distribution and maximum ablation volume is that the electrodes must be placed parallel orientation. Maintaining this configuration can be challenging especially when dealing with deep seated tumors. Thus, the impact of the orientation of the electrodes on the outcomes of IRE is investigated in this project. The influence of the electrode orientation along with various electrode and pulse parameters have also been studied. The IRE experiments were performed using potato tubers. A conductivity test was performed to evaluate the conductivity and electroporation threshold. The electroporated regions of the potato tubers after IRE were reconstructed and compared with the results obtained from numerical models. The temperature between the electrodes was also measured for some electrode orientations. The numerical models were validated using the electroporation results. This numerical model was then extended to study the effect of electrode orientation and a combination of electrode and pulse parameters on the electric field distribution and thermal response. Finally, a statistical test was used to study the significance of these parameters on the electroporated region and the temperature. The results showed that differences in the electroporated regions and temperature obtained between a parallel orientation and a 5 ± sideward and frontal orientation was not significant. Therefore, a 5± tolerance can be defined to obtain a similar response to that of a parallel orientation. The statistical test also revealed that electrode orientations, electrode distance and electrode length had a significant effect on the electric field distribution. The pulse parameters such as pulse width and pulse number influenced the temperature along with the electrode orientations and electrode distance.
Item Type:Essay (Master)
Faculty:EEMCS: Electrical Engineering, Mathematics and Computer Science
Subject:53 electrotechnology
Programme:Electrical Engineering MSc (60353)
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