In-situ monitoring for liquid metal jetting using a millimeter-wave impedance diagnostic.

This article presents a millimeter-wave diagnostic for the in-situ monitoring of liquid metal jetting additive manufacturing systems. The diagnostic leverages a T-junction waveguide device to monitor impedance changes due to jetted metal droplets in real time. An analytical formulation for the time-domain T-junction operation is presented and supported with a quasi-static full-wave electromagnetic simulation model.

A Pilot Study of the Impact of Microwave Ablation on the Dielectric Properties of Breast Tissue.

Percutaneous microwave ablation (MWA) is a promising technology for patients with breast cancer, as it may help treat individuals who have less aggressive cancers or do not respond to targeted therapies in the neoadjuvant or pre-surgical setting. In this study, we investigate changes to the microwave dielectric properties of breast tissue that are induced by MWA. While similar changes have been characterized for relatively homogeneous tissues, such as liver, those prior results are not directly translatable to breast tissue because of the extreme tissue heterogeneity present in the breast.

Inspection of plate weldments through an interposed layer of viscoelastic material using an elastic-electromagnetic scanning method.

In this article, an elastic-microwave based non-destructive evaluation method is presented to inspect for cracks in weldments and thinning of coated steel plates. The approach uses a microwave interferometer operating at 94 GHz to record the total surface displacement of a coated steel plated as it is driven by an incident elastic field. These spatiotemporal data coupled with wavefield processing algorithms provide powerful detection and localization capabilities.

Human Breast Phantoms: Test Beds for the Development of Microwave Diagnostic and Therapeutic Technologies.

Over the past two decades, there has been enormous growth in research activity for microwave diagnostic and therapeutic technologies that target the breast. The clinical need for new tools in the breast cancer armamentarium, combined with the promising lowcost, nonionizing nature of microwave technologies, has fueled these investigations. High-fidelity breast phantoms are essential components of computational and experimental test beds for investigating and accurately assessing the performance of new devices, algorithms, and systems related to microwave breast cancer detection and/or treatment.

Development and application of human breast phantoms in microwave diagnostic and therapeutic technologies.

We highlight recent progress in the development of high-fidelity numerical and physical breast phantoms. These phantoms mimic the anatomical structure and physical properties that are relevant to accurately portraying microwave interactions with the human breast. The phantoms are currently being used in numerous laboratory studies of microwave diagnostic and therapeutic technologies for a variety of potential clinical applications in breast health and disease management.

A TSVD Analysis of the Impact of Polarization on Microwave Breast Imaging using an Enclosed Array of Miniaturized Patch Antennas.

Microwave breast imaging performance is fundamentally dependent on the quality of information contained within the scattering data. We apply a truncated singular-value decomposition (TSVD) method to evaluate the information contained in a simulated scattering scenario wherein a compact, shielded array of miniaturized patch antennas surrounds an anatomically realistic numerical breast phantom. In particular, we investigate the impact of different antenna orientations (and thus polarizations), namely two array configurations with uniform antenna orientations and one mixed-orientation array configuration.

MRI-Derived 3-D-Printed Breast Phantom for Microwave Breast Imaging Validation.

We propose a 3-D-printed breast phantom for use in preclinical experimental microwave imaging studies. The phantom is derived from an MRI of a human subject; thus, it is anthropomorphic, and its interior is very similar to an actual distribution of fibroglandular tissues. Adipose tissue in the breast is represented by the solid plastic (printed) regions of the phantom, while fibroglandular tissue is represented by liquid-filled voids in the plastic.