Ultra-wideband Microwave Ablation Therapy (UMAT)

Abstract

We propose an alternative microwave ablation therapy, Ultra-wideband Microwave Ablation Therapy (UMAT), that can potentially be used for the treatment of various cancers including liver, kidney, breast, lung, and bone. The technology relies on extremely small size ultra-wideband antennas that can deliver power to the tissue with more than 90% power transmission efficiency from beginning to the end of the ablation procedure. The resulting ablation technology is far superior to the existing microwave ablation therapies in terms of power usage, ablation time and zones. In order to validate the system, we provide ex vivo animal experiments.

Design and Characterization of a Minimally Invasive Bipolar Electrode for Electroporation

“…The applicator incorporates a MW antenna that radiates MW power into the surrounding tissue. A variety of single antenna designs have been developed for MW ablation with the objective of efficiently transferring MW power to tissue, with a radiation pattern well matched to the size and shape of the targeted tissue [44][45][46][47].…”

“…The main goal of our study was to reach a trade-off among the treatment invasiveness, linked to the probe diameter, and the electroporated area. Unlike the conventional microwave (MWA) single probes, which can reach ablated area greater than 10 mm despite the invasiveness (diameter are much higher than 1.4 mm [44][45][46][47]), we tried to reduce as much as possible the diameter of the device while still ensuring an electroporated area of at least 10 mm of dimeter. In fact, as reported by Fallahi et al [45], although printed circuit board technologies such as microstrips provide the freedom to design antennas with diverse ablation patterns, achieving a practical device with an overall diameter less than 3 mm is not feasible at common MW ablation frequencies of 915 MHz and 2.45 GHz due to the large wavelength.…”

“…In fact, as reported by Fallahi et al [45], although printed circuit board technologies such as microstrips provide the freedom to design antennas with diverse ablation patterns, achieving a practical device with an overall diameter less than 3 mm is not feasible at common MW ablation frequencies of 915 MHz and 2.45 GHz due to the large wavelength. In Colebeck et al [47], a slot antenna was printed on the back side of a microstrip line with ultra-wideband characteristic. The device is capable of creating ablation zones at 915 MHz, 2.45 GHz and 5.8 GHz.…”

Measuring of Shielding Effectiveness of Electromagnetic Field of Polystyrene in the Frequency Range from 1 GHz to 9 GHz

“…If these factors are unknown, we can measure the intensity of electric field and magnetic field when there are shielding materials or not, and then SE could be calculated by (2). According to [7] the shielding effectiveness is the sum of the reflection R, multiple reflection B and absorption A of electromagnetic field derived as [10], [11], [12]: where t is material thickness, σ is electrical conductivity of shielding material, σR is the relative electrical conductivity, μR is the relative permeability of shielding material, μ is the magnetic permeability of shielding material, f is frequency, δ is depth of penetration. For the simplicity, it is possible to determine the shielding effectiveness SE also as (6) without the multiple reflection B. where μ is permeability which included permeability of the shielding material, ε0 is electric permittivity of vacuum.…”