Graphene-based microwave coaxial antenna for microwave ablation: thermal analysis

Abstract

In this study, the problem of backward heating in microwave ablation technique is examined and an electromagnetic solution based on the use of high impedance graphene material is presented for its mitigation. In this context, a one-atom-thick graphene layer is added on the coaxial double slot antenna. In addition to the electromagnetic behavior, thermal effects caused by the graphene-covered antenna are emphasized. The graphene's conductivity being highly dependent on its chemical potential and the relaxation time, a parametric study is performed to determine a range of tolerances within which the graphene-coated antenna outperform a typical graphene-free antenna. The range of values is found to be 0 < μ c < 0.5 eV and τ < 0.4 ps, for the chemical potential and the relaxation time, respectively. The backward heating problem being prevented, the ablation region is ensured to be spherical around the tip of the antenna. Effects of the graphene layer to the heat dissipation in the tissue, the necrotic tissue ratio (damage to the cancerous tissue of the caused by electromagnetic energy), and the treatment time using the coaxial double slot antenna were examined. The results show that the heat dissipation is concentrated around the slots (region of cancerous tissue) and a higher necrotic tissue ratio can be achieved with a graphene-covered double slot antenna in a shorter time.

Design of a novel externally‐tapped intertwining helical antenna for microwave ablation and its statistical analysis on tissue model

“…Figure 6A shows the rate of ablation from the distal tip of the applicator with tissue characteristics as in Level 1, Table 2. It can be inferred that for 5 min ablation time, 30–40 mm of the transversal diameter of the tissue can be ablated even with higher blood perfusion rate as compared to shifted T‐ring and graphene‐based applicator as in References 39,40. Further, Figure 6B shows the isothermal surface plot at 20 W of input power within 5 min.…”

On the Performance of a Miniaturized Reactive Loaded Monopole Antenna for Ex Vivo Catheter Applications

“…Microwave hyperthermia, characterized by short procedure time and microwave power regulated cell necrosis occurring at elevated temperature (60 0 C), is a minimally invasive clinical modality to ablate deep-seated hepatic, renal and intestinal tumors and for treatment for cardiac arrhythmia and pulmonary disorders [1]- [5]. Over the years, the ablation applicator designs have undergone radical change starting with basic omni-directional antennas like dipoles, monopoles, and slot antennas to triaxial, balun free and flexible catheter antenna designs as documented in [6]- [33] and patented in [34]- [36].…”