Here, we present two different brain diagnostic devices based on microwave technology and the associated first proof-of-principle measurements that show systems can differentiate hemorrhagic from ischemic stroke in acute patients, as well patients healthy volunteers. The system was scattering with an antenna worn head. Measurement data were analyzed a machine-learning algorithm is training using known condition. Computer tomography images used reference. detection methodology evaluated...

Microwave technology has the potential to revolutionize how, when, and what care can be delivered patients with acute, life-threatening medical conditions. The prospects are that microwave systems both improve diagnostic ability accuracy enable earlier diagnosis. Early diagnosis is a key factor in acute situations, especially when breathing circulation affected. Conventional imaging modalities used for diagnostics, such as magnetic resonance (MRI) X-ray computed tomography (CT), powerful but...

A tomographic time-domain reconstruction algorithm for solving the inverse electromagnetic problem is described. The application we have in mind dielectric breast cancer detection but results are of general interest to field microwave tomography. Reconstructions been made from experimental and numerically simulated data objects different sizes order investigate relation between spectral content illuminating pulse quality reconstructed image. We found that crucial a successful reconstruction....

Traumatic brain injury is the leading cause of death and severe disability for young people a major public health problem elderly. Many patients with intracranial bleeding are treated too late, because they initially show no symptoms not transported to trauma center. There need method detect bleedings in prehospital setting. In this study, we investigate whether broadband microwave technology (MWT) conjunction diagnostic algorithm can subdural hematoma (SDH). A human cranium phantom...

In this paper, a time-domain system dedicated to medical diagnostics has been designed, prototype built and its performance evaluated. Measurements show that the 3-dB bandwith of about 3.5 GHz signal noise ratio over 40 dB in frequency range 800 MHz 3.8 GHz. The used perform microwave tomographic image reconstruction test. same target was reconstructed based on data measured with network analyzer. A comparison between images shows very small differences, proves functionality time domain system.

A study is presented where the use of dielectric a priori data in reconstruction algorithm for microwave tomography investigated. new has been developed that includes process. This development made as an extension to conventional conjugate-gradient algorithm. paper further contains numerical results indicate by taking into account, accuracy and ability resolve small objects can significantly be improved. was motivated application biomedical imaging it investigated how knowledge tissue...

The measurement accuracy of an ultrawideband (UWB) time-domain microwave-tomographic system is investigated. In order to make assessment the random variation measurements, repeatability evaluated by comparison with UWB frequency-domain system. A phantom imaged system, and reconstructed images are compared those obtained using results suggest that averaging tens can achieve same level as in interesting frequency range microwave tomography. imaging results, however, indicate reconstruction...

We perform a theoretical analysis of the measurement accuracy ultrawideband time domain systems. The theory is tested on specific system and analytical estimates uncertainty are in good agreements with those obtained by means simulations. influence antennas propagation effects near field microwave imaging systems discussed. As an interesting application, required for breast cancer detection estimated studying effect noise image reconstructions. results suggest that errors reconstructed...

In this paper, quantitative dielectric image reconstruction based on broadband microwave measurements is investigated. A time-domain-based algorithm derived where Debye model parameters are reconstructed in order to take into account the strong dispersive behavior found biological tissue. The tested with experimental and numerical data verify investigate improvements resulting from improved description of properties tissue when using data. comparison made relation more commonly used...

This paper describes a fast microwave tomography reconstruction algorithm based on the two-dimensional discrete dipole approximation. Synthetic data from finite-element solver and experimental imaging system are used to reconstruct images validate algorithm. The measurement consists of 16 monopole antennas immersed in tank filled with lossy coupling liquid vector network analyzer. low-profile nature make approximation an ideal forward image reconstructions. results show that can readily 2D...

This letter describes an efficient three-dimensional (3D) image reconstruction algorithm for microwave tomography. Using the thin-wire approximation with resistive voltage sources (RVS), a realistic FDTD model is created transmitting and receiving antennas. To verify algorithm, made from experimental data using cylindrical test object of sunflower oil. In results, successful has been shown, indicating that applicable. For comparison, two-dimensional (2D) version was made. A significant...

In hyperthermia treatment planning (HTP) the goal is to find amplitudes and phases of antennas in applicator efficiently heat tumor. To do this prior information regarding tumor characteristics such as size, position geometry, addition an exact model needed. Based on information, optimal frequency operation can be determined. paper optimum for based characteristics, using time reversal focusing technique, studied. As we consider size position, number characteristics. The obtained range found...

A breast phantom developed at the Supelec Institute was interrogated to study its suitability for microwave tomography measurements. measurement system based on 16 monopole antennas and a vector network analyzer used how S-parameters are influenced by insertion of phantom. The is 3D-printed structure consisting plastic shells that can be filled with tissue mimicking liquids. different liquids tested determine whether has any effects recovered images or not. Measurements when it same liquid...

Two image reconstruction algorithms for microwave tomography are compared and contrasted. One is a general, gradient‐based minimization algorithm. The other the chirp pulse computed (CP‐MCT) method, which highly computationally efficient method but also best suited low contrasts. results of simulations show that when imaging high‐contrast objects, such as breast cancer tumor, reconstructions made comparable to from algorithm below contrast about 10%. simulations, however, by CP‐MCT very...

Microwave imaging is an interesting and growing research field with a number of medical applications. This paper based on the first series experimental results using iterative gradient algorithm finite difference time domain (FDTD) method synthetic pulses. Using our method, permittivity conductivity object are reconstructed layer by minimizing functional consisting between measured calculated electric surrounding object. done antennas which all in turn transmitting receiving. The dielectric...

Early, preferably prehospital, detection of intracranial bleeding after trauma or stroke would dramatically improve the acute care these large patient groups. In this paper, we use simulated microwave transmission data to investigate performance a machine learning classification algorithm based on subspace distances for bleeding. A computational model, consisting realistic human head models patients with bleeding, as well healthy subjects, was inserted in an antenna array model. The...

A pilot-scale process for continuous in-flow microwave processing of foods, designed and implemented at SP Food Bioscience, was evaluated heat treatment a homogeneous model food high-temperature short-time (HTST) conditions, constant total input power, 2450 MHz. The system has three consecutive cavities, one excited by the TM020 mode that heats primarily in tube centre, two TM120 cavities periphery. temperature uniformity after heating is here terms spatial distribution, different set-ups...

Microwave technology offers the possibility for pre-hospital stroke detection as we have previously demonstrated using non-imaging diagnostics. The focus in this paper is on image-based diagnostics wherein technical and computational complexities of image reconstruction are a challenge clinical realization. Herein investigate whether information about patient's brain anatomy obtained prior to event can be used facilitate A priori by segmenting head tissues from magnetic resonance images....

This paper presents a systematic approach to robust preconditioning for gradient-based nonlinear inverse scattering algorithms. In particular, one- and two-dimensional problems are considered where the permittivity conductivity profiles unknown input data consist of scattered field over certain bandwidth. A time-domain least-squares formulation is employed inversion algorithm based on conjugate gradient or quasi-Newton together with an FDTD-electromagnetic solver. Fisher information analysis...

A microwave tomographic system is used to evaluate the realistic breast phantom developed at Supelec institute. The utilizes 16 monopole antennas and a modern vector network analyzer (VNA) measure phantoms influence on S-parameters. An iterative algorithm then solve inverse problem reconstruct 2-D plane transecting phantom. reconstructed images are compared ones recovered from cylindrical of equivalent media. results show that both possible reconstruct, although interior more challenging.

This letter presents a detailed study of microwave tomography system using 3-D finite-difference time-domain methods (FDTDs). The algorithm, which uses subcell model in form the thin-wire approximation to wire antennas, has been validated numerically published numerical electromagnetic code (NEC) data for dipole and experimentally by comparing with measurements obtained monopole antenna array. agreement between calculated measured performances monopoles is close. In order understand...

In this paper we describe a microwave based measurement setup and signal processing algorithm for stroke detection diagnostics.

Microwave imaging for breast cancer detection has been of significant interest the last two decades. Recent studies focus on solving problem using an inverse scattering approach. Efforts have mainly focused development algorithms, experimental setup, antenna design and clinical trials. However, success microwave also heavily relies quality forward data such that tumor inside volume is well illuminated. In this work, a numerical study conducted. The behavior simple models under different...