Passive Impedance-Matched Neural Recording Systems for Improved Signal Sensitivity.

Wireless passive neural recording systems integrate sensory electrophysiological interfaces with a backscattering-based telemetry system. Despite the circuit simplicity and miniaturization with this topology, the high electrode-tissue impedance creates a major barrier to achieving high signal sensitivity and low telemetry power. In this paper, buffered impedance is utilized to address this limitation.

SkinAid: A Wirelessly Powered Smart Dressing Solution for Continuous Wound-Tracking Using Textile-Based Frequency Modulation.

In this article, SkinAid, a battery-free, low-cost, robust, and user-friendly smart bandage for electrochemical monitoring and sensing of chronic wounds is proposed. The working principle of the bandage is based on direct frequency modulation of a tri-electrode electrochemical sensing of wound data. The electronics and biotelemetry links were realized using low-cost manufacturing process of textile embroidery onto fabric substrate.

Real-Time Detection and 3D Localization of Coronary Atherosclerosis Using a Microwave Imaging Technique: A Simulation Study.

Obtaining the exact position of accumulated calcium on the inner walls of coronary arteries is critical for successful angioplasty procedures. For the first time to our knowledge, in this work, we present a high accuracy imaging of the inner coronary artery using microwaves for precise calcium identification. Specifically, a cylindrical catheter radiating microwave signals is designed.

Multichannel Wireless Neurosensing System for battery-free monitoring of neuronal activity.

Electrical activity recordings are critical for evaluating and understanding brain function. We present a novel wireless, implantable, and battery-free device, namely the Wireless Neurosensing System (WiNS), and for the first time, we evaluate multichannel recording capabilities in vivo. For a preliminary evaluation, we performed a benchtop experiment with emulated sinusoidal signals of varying amplitude and frequency, representative of neuronal activity.

Fully Passive Flexible Wireless Neural Recorder for the Acquisition of Neuropotentials from a Rat Model.

Wireless implantable neural interfaces can record high-resolution neuropotentials without constraining patient movement. Existing wireless systems often require intracranial wires to connect implanted electrodes to an external head stage or/and deploy an application-specific integrated circuit (ASIC), which is battery-powered or externally power-transferred, raising safety concerns such as infection, electronics failure, or heat-induced tissue damage. This work presents a biocompatible, flexible, implantable neural recorder capable of wireless acquisition of neuropotentials without wires, batteries, energy harvesting units, or active electronics.

A Novel Method to Mitigate Real-Imaginary Image Imbalance in Microwave Tomography.

Typical microwave tomographic techniques reconstruct the real part of the permittivity with much greater accuracy as compared to the imaginary part. In this paper, we propose a method to mitigate the imbalance between the reconstructed complex permittivity components and increase the accuracy of the overall image recovery. To do so, the complex permittivity in the imaging domain is expressed as a weighted sum of a few preselected permittivities, close to the range of the expected values.

A Low Frequency Mechanical Transmitter Based on Magnetoelectric Heterostructures Operated at Their Resonance Frequency.

Magneto-elasto-electric (ME) coupling heterostructures, consisting of piezoelectric layers bonded to magnetostrictive ones, provide for a new class of electromagnetic emitter materials on which a portable (area ~ 16 cm²) very low frequency (VLF) transmitter technology could be developed. The proposed ME transmitter functions as follows: (a) a piezoelectric layer is first driven by alternating current AC electric voltage at its electromechanical resonance (EMR) frequency, (b) subsequently, this EMR excites the magnetostrictive layers, giving rise to magnetization change, (c) in turn, the magnetization oscillations result in oscillating magnetic fields. By Maxwell's equations, a corresponding electric field, is also generated, leading to electromagnetic field propagation.

Microscale Silicon Origami.

A new methodology to create 3D origami patterns out of Si nanomembranes using pre-stretched and pre-patterned polydimethylsiloxane substrates is reported. It is shown this approach is able to mimic paper-based origami patterns. The combination of origami-based microscale 3D architectures and stretchable devices will lead to a breakthrough on reconfigurable systems.

Enhanced Microwave Hyperthermia of Cancer Cells with Fullerene.

Hyperthermia generated with various energy sources including microwave has been widely studied for cancer treatment. However, the potential damage due to nontargeted heating of normal tissue is a major hurdle to its widespread application. Fullerene is a potential agent for improving cancer therapy with microwave hyperthermia but is limited by its poor solubility in water for biomedical applications.

Stiffness-Independent Highly Efficient On-Chip Extraction of Cell-Laden Hydrogel Microcapsules from Oil Emulsion into Aqueous Solution by Dielectrophoresis.

A dielectrophoresis (DEP)-based method achieves highly efficient on-chip extraction of cell-laden microcapsules of any stiffness from oil into aqueous solution. The hydrogel microcapsules can be extracted into the aqueous solution by DEP and interfacial tension forces with no trapped oil, while the encapsulated cells are free from electrical damage due to the Faraday cage effect.

A Wireless Fully Passive Neural Recording Device for Unobtrusive Neuropotential Monitoring.

Goal: We propose a novel wireless fully passive neural recording device for unobtrusive neuropotential monitoring. Previous work demonstrated the feasibility of monitoring emulated brain signals in a wireless fully passive manner. In this paper, we propose a novel realistic recorder that is significantly smaller and much more sensitive.

Potential of microbubbles for use as point targets in phase aberration correction.

Bubbles can be produced by vaporization of perfluorocarbon droplets of a few microm diameter. These bubbles can reach over 100 microm in diameter and their backscatter is calculated to be well more than 10 dB above that of several organ tissues. At appropriate sizes, small acoustic amplitudes, and diagnostic frequencies (2-15 MHz), bubbles can be approximated by the nonrigid sphere-scattering solution employed here.