Miniaturized antenna verified with diffuse optical measurements for native and boiled adipose tissue differentiation

Abstract

Medical industries are continuously working towards the development of wearable theragnostic devices which enable monitoring various ailments in the body and then transmitting them to the base-station. The antenna design is of prime importance where the suitable design guarantees proper communication between the antenna and the base-station. In this paper, a co-planar wave-guide antenna is proposed for the use in the medical implant communication service (MICS) band for data transmission. The proposed antenna is studied for ex-vivo applications where the antenna is simulated for bovine intramuscular fat (adipose tissue). The preliminary results showed that the antenna radiates in MICS band. Two types of samples are tested; namely, native fat and boiled fat. The boiled fat is used in order to represent the infected fat tissue. Hence, the antenna was implanted into the fat samples and the results revealed noticeable variations in the radiation characteristics between native and boiled fat. Different parameters of the proposed antenna including the reflection coefficient (S11), radiation patterns, gain, efficiency, and front-to-back ratio are investigated. The simulations showed that S11 parameter was − 12.4 dB in MICS band for the normal fat. On the other hand, the measured S11 values were − 12.3 dB for the native samples and − 9.9 dB for the boiled fat samples. To assert the variation in the biological characteristics of the boiled fat as compared to those of the native fat, diffuse optical measurements of the examined samples were investigated. Such variation in the light scattering and absorbance by the tissue is responsible for varying the S11 parameter for each case. The results have shown that the proposed design is a good candidate for detecting the change in biological tissue.

Multifrequency Microwave Radiometry for Characterizing the Internal Temperature of Biological Tissues

“…In this context, new designs for near-field probes are necessary to improve the matching over biological tissues, maximizing the provided power to the radiometers. Approaches for microwave antennas have been under research over the last years, including configurations using spiral resonators [57], a combination of a symmetric dipole and an annular frame [58], a meander patch antenna [59] or a dielectric-filled waveguide solution [60], among others.…”

Investigating the effect of changing the substrate material analyzed by laser-induced breakdown spectroscopy on the antenna performance

“…Such parameters are essential for accurate diagnosis and effective therapy 5 . Accordingly, various antenna designs in the medical implant communication service (MICS) band have been proposed 6 . However, implantable antennas must contend with constraints such as size, operating frequency authorization, biocompatibility, and varying tissue dielectric characteristics, which impair antenna performance and specific absorption rate (SAR) due to safety concerns 7 .…”