Theoretical Simulation of the Near-Field Probe for Non-Invasive Measurements on Planar Layers with Biological Characteristics

Abstract

The article presents the design of the near-field probe, which is a combined emitter (a combination of a symmetric dipole and an annular frame). The design of the probe allows forming a prolonged zone of the near-field. This effect can be used for in-depth penetration of the field in media with high absorption, without loss of information. Particular attention in this article is given to a detailed study of the interaction of the field created by this probe on plane-layered biological media. A theoretical analysis of the interaction of the electromagnetic field was carried out in a wide frequency band with a model plane-layer biological medium containing blood vessels of shallow depth using the proposed probe design. Conclusions are drawn about the depth of penetration of a useful signal into different media-analogs of biological tissue. This study is necessary to consider the possibility of using this probe for non-invasive measurements of blood glucose concentration. The studies were carried out using numerical simulation in the CST (Computer Simulation Technology) Microwave Studio environment. All biological tissues were simulated over a wide frequency range from 10 MHz to 10 GHz.

Application of Broadband Microwave Near-Field Sensors for Glucose Monitoring in Biological Media

“…Exactly the latter model was used to calculate the dielectric permittivity of the above tissues in a wide frequency range [18,19]. We calculated independently the dependences of the real part of the dielectric permittivity ε of blood, fat, muscles, and bones at frequencies in the range from 10 MHz to 10 GHz [20]. As expected, the tissues comprising aqueous solution (blood, muscles, and skin) have high dielectric permittivity in a wide frequency range.…”

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.…”

Crescent Antennas as Sensors: Case of Sensing Brain Pathology

“…The computational model is evaluated to measure electric field intensity using field probes placed at various regions of interest within the brain. The electric field probes offer valuable insight into the behaviour of electromagnetic fields in the vicinity of sensors [ 32 ]. The electric field probes quantify the strength of the electric field at specific regions within the brain voxel model.…”