Brick-Shaped Antenna Module for Microwave Brain Imaging Systems

Rodriguez-Duarte, D. O.; Vasquez, J. A. Tobon; Scapaticci, Rosa; Crocco, Lorenzo; Vipiana, F.

doi:10.1109/lawp.2020.3022161

Cited by 54 publications

(20 citation statements)

References 21 publications

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“…More importantly, the matching medium increases the antenna bandwidth from 0.82 to 1.1 GHz, which is of great interest for brain imaging. A similar bandwidth of 0.8 to 1.2 GHz has been achieved for a brick antenna proposed recently for microwave brain imaging [ 29 ]. Moreover, the use of the proposed matching medium allows operation in the 1.9–2.2 GHz band, which can be important for improving resolution in microwave breast tomography [ 30 ].…”

Section: Resultsmentioning

confidence: 56%

Development of a Solid and Flexible Matching Medium for Microwave Medical Diagnostic Systems

et al. 2021

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This paper reports the development of a new composite material as a matching medium for medical microwave diagnostic systems, where maximizing the microwave energy that penetrates the interrogated tissue is critical for improving the quality of the diagnostic images. The proposed material has several advantages over what is commonly used in microwave diagnostic systems: it is semi-flexible and rigid, and it can maximize microwave energy coupling by matching the tissue’s dielectric constant without introducing high loss. The developed matching medium is a mirocomposite of barium titanate filler in polydimethylsiloxane (PDMS) in different weight-based mixing ratios. Dielectric properties of the material are measured using a Keysight open-ended coaxial slim probe from 0.5 to 10 GHz. To avoid systematic errors, a full dielectric properties calibration is performed before measurements of sample materials. Furthermore, the repeatability of the measurements and the homogeneity of the sample of interest are considered. Finally, to evaluate the proposed matching medium, its impact on a printed monopole antenna is studied. We demonstrate that the permittivity of the investigated mixtures can be increased in a controlled manner to reach values that have been previously shown to be optimal for medical microwave imaging (MWI) such as stroke and breast cancer diagnostic applications. As a result, the material is a good candidate for supporting antenna arrays designed for portable MWI scanners in applications such as stroke detection.

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Section: Resultsmentioning

confidence: 56%

Development of a Solid and Flexible Matching Medium for Microwave Medical Diagnostic Systems

et al. 2021

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“…The head phantom is covered by a conformal helmet made of ABS (whose relative permittivity and conductivity are 3 and 0.004 S/m, respectively at 1 GHz) and of 24 implemented monopole antennas. Further details on the choice of the antenna array (arrangement and number of antennas, the working frequency and the matching medium), as well as on the brick-shaped antenna module used in the POLITO imaging system are given in [ 54 ] and [ 55 ] respectively. The influence on the E-field distribution, obtained when one of the 24 antennas (the one shown in red in Figure 5 b) is active, is studied by varying parameters such as the coupling medium, chosen with low losses and a dielectric constant of 23 and the printed material (ABS), studied in Section 3.1 , which is reported controversially in [ 56 ].…”

Section: Resultsmentioning

confidence: 99%

A Simulation-Based Methodology of Developing 3D Printed Anthropomorphic Phantoms for Microwave Imaging Systems

et al. 2021

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This work is devoted to the development and manufacturing of realistic benchmark phantoms to evaluate the performance of microwave imaging devices. The 3D (3 dimensional) printed phantoms contain several cavities, designed to be filled with liquid solutions that mimic biological tissues in terms of complex permittivity over a wide frequency range. Numerical versions (stereolithography (STL) format files) of these phantoms were used to perform simulations to investigate experimental parameters. The purpose of this paper is two-fold. First, a general methodology for the development of a biological phantom is presented. Second, this approach is applied to the particular case of the experimental device developed by the Department of Electronics and Telecommunications at Politecnico di Torino (POLITO) that currently uses a homogeneous version of the head phantom considered in this paper. Numerical versions of the introduced inhomogeneous head phantoms were used to evaluate the effect of various parameters related to their development, such as the permittivity of the equivalent biological tissue, coupling medium, thickness and nature of the phantom walls, and number of compartments. To shed light on the effects of blood circulation on the recognition of a randomly shaped stroke, a numerical brain model including blood vessels was considered.

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“…The sensors are simple and modular antennas with a “brick” shape (see Figure 1 c) that integrates a monopole antenna, representing the radiating part, with a brick of dielectric material, acting as a matching medium [ 15 ]. The monopoles are fabricated using printed-circuit technology, guaranteeing repeatability and low-cost, and consist of a triangular-shaped element fed by a microstrip line connected to a rigid coaxial cable.…”

Section: Methodsmentioning

confidence: 99%

“…Hence, it could be compared electromagnetically with an air gap between the face of the brick antenna and the head surface. This constrain was studied by the authors in [ 15 ], where a brick antenna was placed at different distances from the phantom surface, showing adequate penetration in the range of interest for both homogeneous and multi-tissue head. Considering the air-gap limited effect on the signal penetration, the numerical model, used here to generate the discretized scattering operator, considers the head phantom container without thickness.…”

Section: Methodsmentioning

confidence: 99%

Experimental Validation of a Microwave System for Brain Stroke 3-D Imaging

et al. 2021

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This paper experimentally validates the capability of a microwave prototype device to localize hemorrhages and ischemias within the brain as well as proposes an innovative calibration technique based on the measured data. In the reported experiments, a 3-D human-like head phantom is considered, where the brain is represented either with a homogeneous liquid mimicking brain dielectric properties or with ex vivo calf brains. The microwave imaging (MWI) system works at 1 GHz, and it is realized with a low-complexity architecture formed by an array of twenty-four printed monopole antennas. Each antenna is embedded into the “brick” of a semi-flexible dielectric matching medium, and it is positioned conformal to the head upper part. The imaging algorithm exploits a differential approach and provides 3-D images of the brain region. It employs the singular value decomposition of the discretized scattering operator obtained via accurate numerical models. The MWI system analysis shows promising reconstruction results and extends the device validation.

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Brick-Shaped Antenna Module for Microwave Brain Imaging Systems

Cited by 54 publications

References 21 publications

Development of a Solid and Flexible Matching Medium for Microwave Medical Diagnostic Systems

Development of a Solid and Flexible Matching Medium for Microwave Medical Diagnostic Systems

A Simulation-Based Methodology of Developing 3D Printed Anthropomorphic Phantoms for Microwave Imaging Systems

Experimental Validation of a Microwave System for Brain Stroke 3-D Imaging

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