Opto-Ultrasonic Communications in Wireless Body Area Nanonetworks

Abstract—Wirelessly interconnected nanorobots, i.e., engineered devices of sizes ranging from one to a few hundred nanometers, are promising revolutionary diagnostic and therapeutic medical applications that could enhance the treatment of major diseases. Each nanorobot is usually designed to perform a set of basic tasks such as sensing and actuation. A dense wireless network of nano-devices, i.e., a nanonetwork, could potentially accomplish new and more complex functionalities, e.g., in-vivo monitoring or adaptive drug-delivery, thus enabling revolutionary nanomedicine applications. Several innovative communication paradigms to enable nanonetworks have been proposed in the last few years, including electromagnetic communications in the terahertz band, or molecular and neural communications. In this paper, we propose and discuss an alternative approach based on establishing intrabody opto-ultrasonic communications among nanorobots. Optoultrasonic communications are based on the optoacoustic effect, which enables the generation of high-frequency acoustic waves by irradiating the medium with electromagnetic energy in the optical frequency range. We first discuss the fundamentals of nanoscale opto-ultrasonic communications in biological tissues, and then we model the generation, propagation, and detection of opto-ultrasonic waves. I

Intra-Body Communications for Nervous System Applications: Current Technologies and Future Directions

The Internet of Medical Things (IoMT) paradigm will enable next generation healthcare by enhancing human abilities, supporting continuous body monitoring and restoring lost physiological functions due to serious impairments. This paper presents intra-body communication solutions that interconnect implantable devices for application to the nervous system, challenging the specific features of the complex intra-body scenario. The presented approaches include both speculative and implementative methods, ranging from neural signal transmission to testbeds, to be applied to specific neural diseases therapies. Also future directions in this research area are considered to overcome the existing technical challenges mainly associated with miniaturization, power supply, and multi-scale communications.Comment: https://www.sciencedirect.com/science/article/pii/S138912862300163

Wearable Devices for Single-Cell Sensing and Transfection

Wearable healthcare devices are mainly used for biosensing and transdermal delivery. Recent advances in wearable biosensors allow for long-term and real-time monitoring of physiological conditions at a cellular resolution. Transdermal drug delivery systems have been further scaled down, enabling wide selections of cargo, from natural molecules (e.g., insulin and glucose) to bioengineered molecules (e.g., nanoparticles). Some emerging nanopatches show promise for precise single-cell gene transfection in vivo and have advantages over conventional tools in terms of delivery efficiency, safety, and controllability of delivered dose. In this review, we discuss recent technical advances in wearable micro/nano devices with unique capabilities or potential for single-cell biosensing and transfection in the skin or other organs, and suggest future directions for these fields. Highlights • Current wearable sensors have allowed for long-term, real-time detection of specific biomarkers directly from patients. • Miniaturized wearable biosensors with sensing elements interacting with skin or organs can capture target molecules from single cells, which results in significantly increased sensitivity, responding time, and precision. • Emerging wearable devices based on novel nanomaterials or nanofabrication show potential for single-cell detection in cancer cell screening, cardiomyocyte detection, and optogenetics. • Transdermal delivery devices have been scaled down to the micro- and/or nanoscale, and their applications have extended to wide selections of natural molecules and bioengineered molecules. • Emerging nanodevices show unique capabilities in precise single-cell gene transfection in vivo, with improved delivery efficiency, safety, and dose controllability

Information Theoretical Analysis of Synaptic Communication for Nanonetworks

© 2018 IEEE. Communication among neurons is the highly evolved and efficient nanoscale communication paradigm, hence the most promising technique for biocompatible nanonetworks. This necessitates the understanding of neuro-spike communication from information theoretical perspective to reach a reference model for nanonetworks. This would also contribute towards developing ICT-based diagnostics techniques for neuro-degenerative diseases. Thus, in this paper, we focus on the fundamental building block of neuro-spike communication, i.e., signal transmission over a synapse, to evaluate its information transfer rate. We aim to analyze a realistic synaptic communication model, which for the first time, encompasses the variation in vesicle release probability with time, synaptic geometry and the re-uptake of neurotransmitters by pre-synaptic terminal. To achieve this objective, we formulate the mutual information between input and output of the synapse. Then, since this communication paradigm has memory, we evaluate the average mutual information over multiple transmissions to find its overall capacity. We derive a closed-form expression for the capacity of the synaptic communication as well as calculate the capacity-achieving input probability distribution. Finally, we find the effects of variation in different synaptic parameters on the information capacity and prove that the diffusion process does not decrease the information a neural response carries about the stimulus in real scenario

Characterisation of Skin-based THz Communication Channel for Nano-scale Body-centric Wireless Networks

PhDIn pursuit of enhancing the capabilities of healthcare diagnostics and monitoring, the electromagnetic spectrum has been utilized efficiently from the MHz up to THz and beyond. The era of smart phones, wearable devices and on-body networks have unfolded plethora of health applications with efficient channel communication mechanisms, faster data transfer rates and multi-user functionalities. With the advancement in material fabrication and spectroscopic techniques, a new realm of healthcare nanodevices have emerged with immense potential to garner in-depth information of the human body, real-time of tissue morphology, molecular features, hydration level and atmospheric water vapour on channel parameters. In addition to this, engineered skin substitute models: 2D collagen and 3D organotypics, are investigated to address the importance of individual biological features comprising of water dynamics and cell culture, affecting the channel parameters. The experimental results of various tissue samples, skin substitutes and numerical evalua-tion of channel parameters can be used to further improve the communication capabilities of in-body nanonetworks. The original contributions on characterization of skin substitutes can be applied to study various health conditions, effects of drugs and skin ageing on a molecular level. The results presented in this thesis, foresee an increasing demand in skin substitute models due to their biological flexibility and control according to desired medical applications. monitoring and tackle medical emergencies. A collection of these devices with sensing capabilities together form a nanonetwork performing computing tasks such as storage, actuation, data transfer and communication. The thesis brings forth the analysis and optimization of channel parameters; such as pathloss and molecular noise temperature, when the proposed in-body nanodevices communicate amongst each other in the terahertz (THz) range. The novel contribution of the work is mapping the optical properties of human skin by bringing together the measurement of various skin tissues and its influence on channel parameters. In the later part of the thesis, emphasis is given on the individual biological entities of the tissue contributing to channel parameters, such as collagen as an abundant protein, variation in fibrous extra-cellular matrix due to fibroblast cells and amalgamation of different layers; namely, epidermis and dermis of the skin. Recently proposed graphene-based antennas resolve the cumbersomeness of existing medical devices by drastically reducing its size to a few hundreds of nanometres. These biocompatible nanodevices focus on exchanging the intricate details of the human body via nanoscale electromagnetic communication in the terahertz domain of the spectrum. The thesis aims to investigate the material properties of skin tissues with terahertz time do-main spectroscopy and numerically evaluate the channel parameters for in-body nanoscale networks that potentially would form an essential part of a hierarchical body-centric communication network extending from inside the human body to a wider community network. The results are presented in regards to the complexity of human tissue as a channel medium. The measured refractive index and absorption coefficient data is applied to numerically calculate channel pathloss and molecular noise temperature. The results provide a real-time analysi

Nanotools for Neuroscience and Brain Activity Mapping

Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We attribute this disparity, in part, to limitations in current methodologies. Traditional neurophysiological approaches record the activities of one neuron or a few neurons at a time. Neurochemical approaches focus on single neurotransmitters. Yet, there is an increasing realization that neural circuits operate at emergent levels, where the interactions between hundreds or thousands of neurons, utilizing multiple chemical transmitters, generate functional states. Brains function at the nanoscale, so tools to study brains must ultimately operate at this scale, as well. Nanoscience and nanotechnology are poised to provide a rich toolkit of novel methods to explore brain function by enabling simultaneous measurement and manipulation of activity of thousands or even millions of neurons. We and others refer to this goal as the Brain Activity Mapping Project. In this Nano Focus, we discuss how recent developments in nanoscale analysis tools and in the design and synthesis of nanomaterials have generated optical, electrical, and chemical methods that can readily be adapted for use in neuroscience. These approaches represent exciting areas of technical development and research. Moreover, unique opportunities exist for nanoscientists, nanotechnologists, and other physical scientists and engineers to contribute to tackling the challenging problems involved in understanding the fundamentals of brain function

Engineering calcium signaling of astrocytes for neural-molecular computing logic gates.

This paper proposes the use of astrocytes to realize Boolean logic gates, through manipulation of the threshold of [Formula: see text] ion flows between the cells based on the input signals. Through wet-lab experiments that engineer the astrocytes cells with pcDNA3.1-hGPR17 genes as well as chemical compounds, we show that both AND and OR gates can be implemented by controlling [Formula: see text] signals that flow through the population. A reinforced learning platform is also presented in the paper to optimize the [Formula: see text] activated level and time slot of input signals [Formula: see text] into the gate. This design platform caters for any size and connectivity of the cell population, by taking into consideration the delay and noise produced from the signalling between the cells. To validate the effectiveness of the reinforced learning platform, a [Formula: see text] signalling simulator was used to simulate the signalling between the astrocyte cells. The results from the simulation show that an optimum value for both the [Formula: see text] activated level and time slot of input signals [Formula: see text] is required to achieve up to 90% accuracy for both the AND and OR gates. Our method can be used as the basis for future Neural-Molecular Computing chips, constructed from engineered astrocyte cells, which can form the basis for a new generation of brain implants