Electric Field Distribution Study of Hexagonal and Pentagonal Electrode Geometries

The over 9 million deaths in 2018, and 10 million in 2020, worldwide, due to cancer, indicates that the current standard of treatments is inadequate; there is an urgent and critical need for additional/alternate physical therapies. Towards this, electroporation-based chemotherapy, known as Electrochemotherapy is emerging. This involves application of high intensity, short duration pulses at the tumor site, which enhances the biopotential across the phospholipid bilayers of the cell plasma membrane and hence opens up pores for enhanced uptake. The electric field intensity and distribution is shaped by the electrode geometry, size, material and the tissue treated.

In this research, we investigated the influence of different electrodes on the electric field intensity and distribution. For this purpose, platinum and surgical steel needle array hexagonal and pentagonal electrodes were used. ANSYS, the industry standard software that uses finite element method was used to study the electric field distribution, intensity and contour. Both, healthy tissue and tumor tissue were used to identify the electric field intensity and distribution using these various electrode configurations and materials, for unipolar and bipolar voltages were studied.

The results indicate that the electric field distribution, both in magnitude and pattern is similar for both electrodes, for both configurations and materials, which is desired from the clinical aspect. The electric field intensities for the hexagonal and pentagonal needle electrodes were 1280V/cm and 1180V/cm respectively in the case of tumor tissue (correlating well with the desired level of 1200V/cm). They were 835V/cm and 843V/cm for these electrodes in the case of healthy tissues. The values were same in the case of bipotential and negative voltages too.