Date of Award
Master of Science (MS)
Nanosecond pulsed electric field (nsPEF) for cancer therapy is characterized by applications of high voltage pulses with low pulsed energy to induce non-thermal effects on tissues such as tumor ablation. It nonthermally treats tissues via electroporation. Electroporation is the increase in permeabilization of a cell membrane due to the application of high pulsed electric field. The objective of this study was to investigate the effect of nsPEF on tissue by monitoring the tissue’s impedance in real-time. Potato slices (both untreated and electroporated), and tumors extracted from female BALBc mice were studied. 100ns, 1-10kV pulses were applied to the tissues using a four-pin electrode at a pulse repetition frequency of 3Hz. The impedance change during the treatment was recorded by a custom made V-I monitor, and a network analyzer measured the impedance before and after treatment over a frequency range of 100kHz to 30MHz. In addition, system calibration was conducted to ensure the accuracy of the measurements. This includes determination of the attenuation offered by the V-I monitor measured to be 60dB and the cell constant K which represents the geometry of the four-pin electrode measured to be 0.8453𝑐𝑚−1 (±0.02cm). Results show that the impedance of tissue reduced with increasing number of pulses and voltage applied, up to 44.4% and 22.3% decrease in the impedance of potato and tumor tissues were respectively observed. Also, the impedance values were higher at lower frequencies compared to those at higher frequencies. This is due to the high resistance of the membrane at low frequencies.
Oshin, Edwin A..
"Impedance Analysis of Tissues in nsPEF Treatment for Cancer Therapy"
(2020). Master of Science (MS), Thesis, , Old Dominion University, DOI: 10.25777/0w39-ed19