1,721,025 research outputs found
A Simple Quantitative Inversion Approach for Microwave Imaging in Embedded Systems
No full textIn many applications of microwave imaging, there is the need of confining the device in order to shield it from environmental noise as well as to host the targets and the medium used for impedance matching purposes. For instance, in MWI for biomedical diagnostics a coupling medium is typically adopted to improve the penetration of the probing wave into the tissues. From the point of view of quantitative imaging procedures, that is aimed at retrieving the values of the complex permittivity in the domain under test, the presence of a confining structure entails an increase of complexity of the underlying modelling. This entails a further difficulty in achieving real-time imaging results, which are obviously of interest in practice. To address this challenge, we propose the application of a recently proposed inversion method that, making use of a suitable preprocessing of the data and a scenario-oriented field approximation, allows obtaining quantitative imaging results by means of quasi-real-time linear inversion, in a range of cases which is much broader than usual linearized approximations. The assessment of the method is carried out in the scalar 2D configuration and taking into account enclosures of different shapes and, to show the method's flexibility different shapes, embedding nonweak targets
Women Radio Science Contributions: A Special Greeting to Pat Doherty [Women in Engineering]
No full textWomen's Contributions in Electromagnetic Inverse Problems [Women in Engineering]
No full textScience is often considered a male-dominated field. Today, women are still discouraged from entering the fields of technology, engineering, and math and, in the last two years, the COVID-19 pandemic has worsened this situation. Nevertheless, despite challenges of gender discrimination and lack of recognition in the scientific community, countless inspiring women in these fields have made historic contributions to science and helped develop a better understanding of the world around us. Many women were not recognized in their own lifetimes, but their achievements have helped generations of female scientists to come
Towards a low-complexity microwave imaging strategy for liver ablation monitoring
No full textThermal ablation represents an innovative treatment strategy for liver cancer therapy, having tangible advantages with respect to surgery. However, the main shortcoming, particularly crucial for microwave thermal ablation, is the necessity of monitoring in real time the treated region, so to provide information on the effectiveness of the treatment. Microwave imaging has been recently proposed as an effective tool for this goal, as it is capable of imaging the dielectric properties variations of liver tissues undergoing the ablation therapy. First investigations on simulated and experimental data corroborated the expected potentials. In this communication, a novel imaging approach able to work with a simplified measurement set-up is presented. The system simplification consists in a reduction of the number of antennas and in a measurement protocol which does not require any movement of the antenna array nor of the target under test. Preliminary results on experimental data are reported
Microwave imaging for liver thermal ablation monitoring. Developing an experimental set-up
No full textThermal ablation has been recognized as an effective method for liver malignancy treatment. The clinical difficulties lie in monitoring the treatment process in realtime. In recent years, microwave imaging has been proposed as a modality with out-standing features such as non-ionizing nature, cost-effective, and capable of realtime monitoring. In this respect, in this contribution, a low-complexity experimental set-up for the experimental assessment of microwave imaging system for liver ablation monitoring is proposed and numerically assessed. The reconstruction of images inside the liver shows that it is possible to localize the ablation zone in the abdomen phantom during the thermal ablation treatment. The results of this study lay the foundations for the experimental assessment of microwave imaging systems for thermal ablation monitoring
Innovative imaging tools and devices for clinical monitoring within the EMERALD network
No full textThe Marie Skłodowska-Curie Innovative Training Network EMERALD is a recently started project aimed at progressing the state of the art of microwave imaging devices for medical applications. In this framework, the goal of the project tasks based at CNR-IREA is twofold. First, ad-hoc imaging algorithms tailored to the prototype devices for clinical follow-up and image-guided treatment designed and realized within the network will be developed. Second, a microwave imaging device for monitoring and guiding microwave ablation treatments will be designed, realized and tested. This paper presents the initial research activities carried out by the CNR-IREA team within the EMERALD project
Towards a microwave imaging system for continuous monitoring of liver tumor ablation: Design and in silico validation of an experimental setup
Full text linkLiver cancer is one of the most common liver malignancies worldwide. Thermal ablation has been recognized as a promising method for its treatment, with a significant impact on clinical practice. However, the treatment’s effectiveness is heavily dependent on the experience of the clinician and would improve if paired with an image-guidance device for treatment monitoring. Conventional imaging modalities, such as computed tomography, ultrasound, and magnetic reso-nance imaging, show some disadvantages, motivating interest in alternative technologies. In this framework, microwave imaging was recently proposed as a potential candidate, being capable of implementing real-time monitoring by means of low-cost and portable devices. In this work, the in silico assessment of a microwave imaging device specifically designed for liver ablation monitoring is presented. To this end, an imaging experiment involving eight Vivaldi antennas in an array config-uration and a practically realizable liver phantom mimicking the evolving treatment was simulated. In particular, since the actual phantom will be realized by 3D printing technology, the effect of the plastic shells containing tissues mimicking materials was investigated and discussed. The outcomes of this study confirm that the presence of printing materials does not impair the significance of the experiments and that the designed device is capable of providing 3D images of the ablated region conveying information on its extent and evolution. Moreover, the observed results suggest possible improvements to the system, paving the way for the next stage in which the device will be implemented and experimentally assessed in the same conditions as those simulated in this study
A compact slot-loaded antipodal vivaldi antenna for a microwave imaging system to monitor liver microwave thermal ablation
Full text linkThis study presents the design and the experimental validation of a slot-loaded antipodal Vivaldi antenna. The intended use is in an array configuration for monitoring liver microwave thermal ablation by way of microwave imaging (MWI). To optimize electromagnetic power transfer to the human abdomen, the antenna was designed to operate in a coupling medium. The final design has overall dimensions of 40 mm × 65 mm, and the working bandwidth goes from 600 MHz up to 3 GHz, with the possibility to operate at higher frequencies, also. The antenna proposed in this study shows the most compact aperture dimension, as compared with other antennas designed for biomedical applications, working within the same bandwidth. To experimentally evaluate the antenna performances, the coupling medium was realized, proposing a recipe made by low cost, and easy to provide and use, materials. In particular, a mixture of water, oil, dishwashing detergent, and guar gum was used. The realized material showed dielectric properties close to the target ones, proved stability on a 1-week time, and reproducibility against different realizations. The antenna's measured S-parameters well agreed with the simulation result. When locating two antennas in close proximity, as in the MWI array configuration, the results showed good performances towards mutual coupling
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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