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Rapid advances in antennas, propagation, electromagnetics, and materials are opening new and unexplored opportunities in body area sensing and stimulation. Next-generation wearables and implants are seamlessly providing round-the-clock monitoring. In turn, numerous applications are brought forward with the potential to ultimately transform healthcare, sports, consumer electronics, and beyond. This review paper provides a comprehensive overview, discusses challenges and opportunities, and indicates future directions for: (a) enabling technologies needed to make body area sensing and stimulation a reality, and (b) emerging bioelectromagnetics applications that may readily benefit from such technologies.

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. Methods: The proposed recorder utilizes a highly efficient microwave backscattering method and operates without any formal power supply or regulating elements. Also, no intracranial wires or cables are required. In-vitro testing is performed inside a four-layer head phantom (skin, bone, gray matter, and white matter). Results: Compared to our former implementation, the neural recorder proposed in this study has the following improved features: 1) 59% smaller footprint, 2) up to 20-dB improvement in neuropotential detection sensitivity, and 3) encapsulation in biocompatible polymer. Conclusion : For the first time, temporal emulated neuropotentials as low as 63 μVpp can be detected in a wireless fully passive manner. Remarkably, the high-sensitivity achieved in this study implies reading of most neural signals generated by the human brain. Significance: The proposed recorder brings forward transformational possibilities in wireless fully passive neural detection for a very wide range of applications (e.g., epilepsy, Alzheimer's, mental disorders, etc.). [ABSTRACT FROM PUBLISHER]

A high-sensitivity, fully passive neurosensing system is presented for wireless brain signal monitoring. The proposed system is able to detect very low-power brain-like signals, viz. as low as -82 dBm (50 \mu\Vpp) at fneuro>\ 1 kHz. It is also able to read emulated neural signals as low as -70 dBm (200 \mu\Vpp) at fneuro>\ 100 Hz. This is an improvement of up to 22 dB in sensitivity as compared with previously reported neural signals. The system is comprised of an implanted neurosensor and an exterior interrogator. The neurosensor receives an external carrier signal and mixes it with the neural signals prior to retransmitting to the interrogator. Of importance is that the implanted neurosensor is fully passive and does not require a battery nor rectifier/regulator but is concurrently wireless for unobtrusive neurosensing with minimal impact to the individual's activity. To achieve this remarkable high sensitivity, the sensing system employed: 1) a subharmonic mixer using an anti-parallel diode pair; 2) a pair of implanted/interrogator antennas with high transmission coefficient \vertS21\vert;and 3) a matching circuit between the implanted antenna and the mixer. This neurosensing system brings forward a new possibility of wireless neural signal detection using passive brain implants. [ABSTRACT FROM PUBLISHER]

Blood vessels are continuously exposed to various stresses such as mechanical strains and neurosignals. Besides its role as a barrier between blood and other tissues, the endothelium is a highly important cell layer for the regulation of vascular tone. Indeed, depending on the signal perceived by endothelial cells, it can drive a vasoconstrictor or vasodilator signal. This review presents mechano-receptors and neuro-receptors (restricted to neuropeptides) leading to vessel relaxation via the production of nitric oxide. Finally, some pieces of evidence of a potential cross-talk between these two kinds of stimuli are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The fabrication of three-dimensional platinum nanoprotrusions by ion beam induced deposition (IBID) is here proposed to study their interaction with cultured rat primary neurons. The broad versatility of IBID allows to test the effects on cells network morphology of different protrusions shapes, from straight pillars to nail-headed or sphere-headed vertical structures. A preferential adhesion of cells on fabricated Pt nanostructures is clearly shown by fluorescence and scanning electron microscopy, with dense and suspended neuritic networks observed on arrays of large-headed pillars. This technique could be exploited to improve cells/electrodes adhesion and to increase the detected extracellular electric signal. [Copyright &y& Elsevier]

The simultaneous neural signal monitoring and stimulation can allow accurate neurotransmitter regulation for patients in various degrees of neural degeneration disorders. Here, we developed a residue-free graphene device as an effective electrical neural interface for dopamine sensing and secretion. We demonstrated the ultrasensitive dopamine sensing of residue-free graphene devices cultured with PC12 cells and the on-demand functional electrical stimulation for electroceutical applications. The doping effect of graphene by the released dopamine from living cells was confirmed from the electrical current change. The dopamine release could be also quantitatively analyzed by ELISA. Then, Ca 2+ ion-dependent dopamine release was optically observed by fluorescence microscopy during the stimulation. Taken together, this study confirms the feasibility of graphene surface as a neural interface for electroceutical applications to various central nerve system disorders.