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A female volunteer is scanned daily using a system to measure bulk permittivity of the breast. The measured data are then compared to the volunteer's menstrual cycle. A permittivity increase of about 10% is found during the luteal phase compared to the follicular phase of the cycle. This correlates with breast density increase reported with X-ray mammography during the luteal phase.
Magnetic nanoparticles have been recently proposed as a contrast agent for breast cancer microwave imaging. In this communication, we report on the ongoing activities aiming at the feasibility validation of magnetic nanoparticles enhanced microwave imaging. In particular, we discuss the results of some experiments, carried out to deal with the factors that influence the detection limits of the technique...
Magnetic modulated nanoparticles are a promising approach to enhance microwave breast cancer detection and imaging. Assuming that functionalized magnetic nanoparticles are able to accumulate selectively within tumorous tissue, this approach can increase the diagnostic reliability. This contribution deals with detecting and imaging of magnetic nanoparticles by means of ultra wideband sensing. Magnetic...
Quantitative microwave holography is a recently proposed imaging method that offers quantitative reconstruction in a quasi-real time. Since it is a direct inversion method, its utility is limited to weak-scattering problems. The feasibility of microwave holography in tissue reconstruction is studied here. The reconstruction results are promising, suggesting microwave holography is suitable as a linear...
In this work, we present a non-conventional coplanar microwave antenna for near-field applications. This electrical probe is a combination of coplanar line and the point effect. We achieved prototypes of micro-antennas using the clean room techniques. To overcome the oxidation problem, we chose gold as metal structure. We used an oxidized silicon substrate in order to reduce losses in the silicon...
An approach for microwave imaging of hemorrhagic brain strokes is proposed in this paper. The developed procedure is based on the solution of the electromagnetic inverse-scattering problem by using a Newton-scheme developed in the framework of the LP Banach spaces. Preliminary numerical results, aimed at evaluating the feasibility of the developed approach for brain stroke detection, are reported.
Microwave imaging offers an alternative modality for breast cancer screening and for the diagnosis of cerebrovascular accidents. Before clinical application, the performances of microwave imaging systems have to be assessed on anatomically detailed anthropomorphic phantoms. This paper presents advances in the development of breast and head phantoms based upon 3D-printed structures filled up with liquid...
A new multistatic microwave imaging system containing specially designed antennas to avoid strong reflections at the interface to material samples with high dielectric constant is presented. The structure consists of a switched antenna array put in direct contact with the material in analysis and able, thanks to the antenna design, to minimize the interface impedance mismatch.
This work presents some preliminary results from applying our previously developed microwave imaging algorithm based on two-step iterative shrinkage/thresholding (TwIST) to data measured from an experimental microwave imaging system. Combining the distorted Born iterative method (DBIM) with the TwIST linear solver, our two-dimensional (2-D) algorithm is applied to reconstruct 2-D slices of the complex...
In this paper, a microfluidic planar resonator sensor is proposed to identify the unknown dielectric constant of liquid solvents. The frequency response from known permittivity of solvents is critically analyzed using polynomial plotting graphs. Meanwhile, high sensitivity detection sensor with more than 400 quality factor and 0.27% maximum different percentage measurement is observed between proposed...
Microwave and mm-wave imaging systems for breast cancer detection are pursued to provide an additional technique with respect to current approaches, mostly based x-rays, ultrasounds, and magnetic resonance. The use of non-ionizing radiation and the relatively low cost are among the most important advantages, but often with resolution or attenuation below expectations for microwave and mm-wave systems,...
We present a breast phantom for experimental medical microwave imaging. The phantom structures separating the tissue mimicking liquids are 3D-printed based on conductive materials. The skin is cast by silicone composites with carbon powder and graphite. In comparison to 3D printing with common plastic, this approach allows the simulation of anatomical breast structures with improved dielectric characteristics.
Based on the synthetic interferometric imaging technique (SAIR), a new microwave radiometer architecture is proposed in this paper to detect thermal noise sources with a passive coded measurement approach so called CSAIR. In this new system, a passive microwave device is used to intrinsically code and multiplex the antenna signals. This allows the reduction of the number of RF chains while keeping...
In this paper, a flexible directional monopole antenna for wearable head imaging system for stroke detection is presented. To ensure better flexibility for wearable applications, a very thin flexible PET substrate, Melinex 339 with thickness of 75μm is utilized. The size of the antenna is 70mm × 30mm. An array of 8 antennae are arranged in elliptical configuration to follow a human head contour. The...
Microwave ablation (MWA) is widely recognized as a promising treatment tool for cancer. Real-time monitoring of the dimensions of the ablation zone is indispensable for ensuring an effective and safe treatment. In this paper, we propose a microwave imaging algorithm for monitoring the evolution of the ablation zone. This algorithm estimates the boundary of the ablation zone by exploiting the time...
In this work we present an experimental study of qualitative microwave imaging algorithms for breast cancer detection. All the experiments are carried out with a 3-D printed realistic breast phantom filled with designed tissue mimicking liquids. In the following, the first experimental results using the Truncated Singular Value Decomposition (TSVD) scheme and the Linear Sampling Method (LSM) reconstructions...
We are presenting a new application of microwave microscopy for the diagnostic of the lightning strike protection mesh used in composite aircraft skin. With this new approach it is possible to resolve defects as small as one cut strand under the paint. We also discuss its ability to measure the paint thickness.
This paper proposes a novel technique for retrieving the dielectric features of weak scatterers in microwave imaging by means of a Compressive Sensing (CS)-based method enhanced by a multi-zoom strategy. A Relevance Vector Machine (RVM) is used to invert the data of the problem recast in a Bayesian framework, exploiting the combination of the a-priori information on the sparseness of the unknowns...
This paper presents a novel approach to microwave hyperthermia exploiting magnetic nanoparticles as focusing agents, and reports the results of a 2D numerical study aimed at preliminarily assessing its effectiveness. The approach exploits magnetic nanoparticles, locally supplied to the tumor, to induce, through an external polarizing magnetic field, a detectable variation of its magnetic contrast...
This paper summarizes the recent advances in using frequency-diverse metasurfaces for computational imaging in the microwave and millimeter wave regimes. Frequency-diverse apertures are defined as structures that can generate distinct radiation patterns as a function of frequency. Such waveforms can multiplex a scene information into a set of backscattered measurements, which can be decoded using...
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