Feasibility Study of a Robotic Plasma Medicine Device Using Numerical Simulation
Abstract
A concept design of a robotic plasma medicine device is presented, which can generate cold atmospheric plasma (CAP) inside of the human body and deliver CAP through a dynamically moving tip to treat exposed cancers. To explore the feasibility of the design concept, numerical models are developed using COMSOL v5.4, a commercially available finite element analysis modeling software. However, due to the limitations of the current state-of-the-art simulation technologies, an individualized physics approach to this problem is necessary. Using three decoupled physics models, the stability of gas flow, the electrical insulation required for safe in vivo use, and the effects of various design and operating parameters on the plasma are investigated. Design and operating parameters studied in this research include tip velocity, tip angle, applied voltage, and electrode spacing.
The effect a dynamic tip has on the radial velocity profile exiting the device was revealed by the neutral gas flow study. Thus, a decreased angular tip velocity would be required to reduce these potential effects when treating larger areas. The results from the electrostatics study ensured that there was no electric field outside of the device, and the ground shield would prevent any potential breakdown from occurring externally. Additionally, the region of the insulation containing electric field values greater than the insulation’s dielectric strength was significantly localized. The plasma operation study demonstrated the effects of varying the electrode spacing and applied voltage on the discharge characteristics including electron density, electron temperature, discharge current, and plasma power. The afterglow chemistry model allowed a connection to made in terms of how the plasma discharge characteristics produced in the variance of applied voltage and electrode spacing effect a device’s potential ability to treat cancer through the generation of reactive oxygen species (ROS) including O, Ov2( ^1D), Ov3, OH, HOv2, H2O^2, and O-/v 2 . Both 5 mm and 10 mm electrode spacings demonstrated the ability to produce relatively high concentrations of ROS across a voltage range of 5 kV to 10 kV.
Citation
McKinney, Will Brendan (2019). Feasibility Study of a Robotic Plasma Medicine Device Using Numerical Simulation. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /200720.