We present a computationally efficient and robust image reconstruction algorithm for breast cancer detection using an ultrawideband confocal microwave imaging system. To test the efficacy of this approach, we have developed a two-dimensional (2-D) anatomically realistic MRI-derived FDTD model of the cancerous breast. The image reconstruction algorithm is applied to FDTD-computed backscatter signals, resulting in a microwave image that clearly identifies the presence and location of the malignant lesion. These simulations demonstrate the feasibility of detecting and imaging small breast tumors using this novel approach.

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A confocal microwave imaging algorithm for breast cancer detection

A new image reconstruction algorithm, termed as delay-multiply-and-sum (DMAS), for breast cancer detection using an ultra-wideband confocal microwave imaging technique is proposed. In DMAS algorithm, the backscattered signals received from numerical breast phantoms simulated using the finite-difference time-domain method are time shifted, multiplied in pair, and the products are summed to form a synthetic focal point. The effectiveness of the DMAS algorithm is shown by applying it to backscattered signals received from a variety of numerical breast phantoms. The reconstructed images illustrate improvement in identification of embedded malignant tumors over the delay-and-sum algorithm. Successful detection and localization of tumors as small as 2 mm in diameter are also demonstrated.

Confocal Microwave Imaging for Breast Cancer Detection: Delay-Multiply-and-Sum Image Reconstruction Algorithm

Methods and apparatuses are provided for reducing sweat production via, for example, the removal, disablement, and incapacitation of sweat glands in the epidermis, dermis and subdermal tissue regions of a patient. In one embodiment, a method of treating a patient is provided which involves identifying a patient having a condition of excessive sweating, positioning an energy delivery device proximate to a skin tissue of the patient and delivering energy to sweat glands to halt secretion of sweat. The energy delivery device may include microwave delivery devices, RF delivery devices, and cryogenic therapy devices. Some embodiments may include using a cooling element for avoiding destruction of non-target tissue and/or a suction device to localize treatment at specific portions of the skin fold.

Methods and apparatus for reducing sweat production

The present invention is directed to systems, apparatus, methods and procedures for the noninvasive treatment of tissue using microwave energy. In one embodiment of the invention a medical device and associated apparatus and procedures are used to treat dermatological conditions using microwave energy.

Systems, apparatus, methods and procedures for the noninvasive treatment of tissue using microwave energy

An tissue interface module has an applicator chamber on a proximal side of the tissue interface module and a tissue acquisition chamber on a distal side of the tissue interface module. The applicator chamber may include: an opening adapted to receive the applicator; an attachment mechanism positioned in the applicator chamber and adapted to attach the tissue interface module to the applicator; a sealing member positioned at a proximal side of the applicator chamber; and a vacuum interface positioned at a proximal side of the applicator chamber and adapted to receive a vacuum inlet positioned on a distal end of the applicator. The invention also includes corresponding methods.

Applicator and tissue interface module for dermatological device

Three different perspectives of electromagnetic radiation are presented here. The first employs the electric-field kink model, the second is based on a technique called FARS (Farfield Analysis of Radiation Sources), and the third uses time-domain solutions obtained from the TWTD (Thin-Wire Time Domain) model. The kink model demonstrates qualitatively that radiation is produced by “wriggling” a charge. The latter two provide more quantitative results, showing that radiation for a straight dipole can come not only from the source region and ends but also from along its length.

A Multi-Perspective Examination of the Physics of Electromagnetic Radiation

In this paper, a circularly polarized, dual-frequency, slotted square patch is designed with probe feeding mechanism to operate as the telemetry, telecommand and control (TT&C) antenna for satellite spacecrafts at 2.25GHz and 3GHz. This antenna is designed and optimized using 3D EM modeling. Several optimizations are performed to obtain the optimum values of the antenna physical parameters. Then a prototype is fabricated on a low loss te∞on microstrip substrate and measured using VNA. Measurements are in great agreement with simulations, which verifles the design procedure and strongly recommends the proposed structure for TT&C satellite system applications.

A Circularly Polarized Dual-frequency Square Patch Antenna for TT&C Satellite Applications

For practical bio-electromagnetic applications, such as the interaction of electromagnetic fields with the human head and body, accurate simulation of biological tissues is a key factor for reliable results. The characteristics of biological tissues are frequency dependent and thus called dispersive materials. For accurate FDTD simulation of biological tissues, a numerical technique is proposed to derive the Debye coefficients from the measured frequency-dependent permittivity of different biological tissues, and then a scattered field FDTD formulation is developed for such dispersive media characterized by multi-term Debye expressions. The proposed scattered field FDTD formulation is valid for three dimensional analysis of practical EM problems involving combination of dispersive and non-dispersive materials. The developed procedure has been verified for different types of biological tissues over a very wide band of frequency (from 30 Hz to 20 GHz). The reflection coefficients of a semi-infinite dispersive medium using one, two, and three-term Debye expressions are computed and compared favorably with the corresponding analytical solution. Hence, the accuracy and stability of modeling multi-term Debye dispersive materials using the proposed scattered FDTD formulation is assessed.

Accurate FDTD simulation of biological tissues for bioelectromagnetic applications

The performance of a diversity system is evaluated by both the antenna gain and diversity gain. Good diversity gain is generally obtained for antenna diversity systems with minimized cross correlation and coupling effects. Therefore, this paper introduces numerical and graphical algorithms to estimate the envelope correlation coefficient (rhoe), and hence the parameters for optimum antenna diversity configuration are derived. The proposed procedure is based on numerical calculations of relevant derived formula for rhoe in terms of the propagation environment and the antenna pattern. A more convenient way is presented to estimate rhoe from the scattering parameters, and the normalized mutual resistance R12 between diversity antenna ports. Moreover, different co-polar, and cross-polar antenna pattern cuts in principal planes, are used to evaluate and analyze the correlation characteristics. The developed algorithms are then applied to investigate the performance of spatial diversity antenna systems.

Correlation characteristics of diversity antennas in mobile environments

A novel compact planar 2 × 2 antenna system with super-wide bandwidth is presented in this paper The MIMO antenna has four square-shaped patches with two slots in each that are interconnected with each other using four strip lines printed on a substrate of Rogers Duroid RT 5880 with relative permittivity of er = 22 and tangent loss of δ = 00009 The proposed antenna system has a partial ground plane with two enhancement fractured slots The design is characterized by a super-wide impedance starting from 152 to 62 GHz (a bandwidth of 468 GHz) and compact total system size of 112 × 1525 mm2 with a thickness of 012 mm The proposed MIMO design has omnidirectional radiation pattern for far field and the achieved peak gain reaches 135 dBi The presented planar antenna which relies on computer aided design, has been designed and simulated using an industrial standard simulation code Its performance results showed that the MIMO design is characterized by super wide bandwidth, omnidirectional radiation pattern, and high-power gain with miniaturized physical size; thus, it is suitable for radio-frequency identification (RFID) systems, fifth-generation applications, ultra-wideband systems, and others

https://www.mdpi.com/2073-8994/13/2/233/pdf

Mohamed Eleiwa

Papers

A Multi-Perspective Examination of the Physics of Electromagnetic Radiation

A Circularly Polarized Dual-frequency Square Patch Antenna for TT&C Satellite Applications

Accurate FDTD simulation of biological tissues for bioelectromagnetic applications

Correlation characteristics of diversity antennas in mobile environments

Compact Design of 2 × 2 MIMO Antenna with Super-Wide Bandwidth for Millimeters Wavelength Systems