Real-Time Digital Signal Processing Demonstration Platform

In order to demonstrate various digital signal processing (DSP) algorithms to students or potential students, a program was developed that runs in real-time on low cost, commercially available hardware. The program includes several common DSP algorithms such as lowpass filter, highpass filter, echo, reverb, quantization, aliasing, simple speech recognition, and fast Fourier transform (FFT). The program allows the user to easily switch between algorithms, to adjust the parameters of the algorithms, and to immediately hear the results. The demonstration hardware consists of the TMS320C5515 eZdsp USB Stick, a powered microphone, an audio source such as an MP3 player or cellphone, and speakers. Undergraduate electrical engineering students were shown the demonstration and were surveyed to determine which algorithms they found most interesting. The C language source code for the software is available from the author for free, so this program can be modified by instructors who wish to make their own demonstrations or used as a convenient starting point for student projects

Technological agglomeration and the emergence of clusters and networks in nanotechnology

Based on the analysis of two clusters in nanotechnologies (MESA+ in the Netherlands and Minatec in Grenoble in France), the paper examines the emergence and effects of technological agglomeration. The social and technical arrangements of a regional centre for nanotechnology both enable and constrain the ongoing activities and research lines that can be followed. Technology platforms and their co-location are a pre-requisite for nanotechnology research and agglomeration of such platforms are both a means and outcome for institutional entrepreneurs to mobilise resources, build networks and construct regional centres of excellence in nanotechnology. Technological agglomeration shapes the networks that evolve and leads to the convergence of scientific disciplines.TECHNOLOGICAL AGGLOMERATION;TECHNOLOGY PLATFORM;CLUSTER;DISTRICT; CONVERGING TECHNOLOGY;MULTILEVEL ACTIVITIES

WSU Research News, Fall 2006

A twenty page newsletter of the WSU Research News. The WSU Research News was published monthly beginning in June of 1968 and issued by the Office of Research Development. This newsletter was created to provide information to the WSU faculty about the availability of outside funds for research and educational programs, new developments that may affect availability of funds, and general information on research and educational activities at Wright State University.https://corescholar.libraries.wright.edu/wsu_research_news/1192/thumbnail.jp

Exploiting All-Programmable System on Chips for Closed-Loop Real-Time Neural Interfaces

High-density microelectrode arrays (HDMEAs) feature thousands of recording electrodes in a single chip with an area of few square millimeters. The obtained electrode density is comparable and even higher than the typical density of neuronal cells in cortical cultures. Commercially available HDMEA-based acquisition systems are able to record the neural activity from the whole array at the same time with submillisecond resolution. These devices are a very promising tool and are increasingly used in neuroscience to tackle fundamental questions regarding the complex dynamics of neural networks. Even if electrical or optical stimulation is generally an available feature of such systems, they lack the capability of creating a closed-loop between the biological neural activity and the artificial system. Stimuli are usually sent in an open-loop manner, thus violating the inherent working basis of neural circuits that in nature are constantly reacting to the external environment. This forbids to unravel the real mechanisms behind the behavior of neural networks. The primary objective of this PhD work is to overcome such limitation by creating a fullyreconfigurable processing system capable of providing real-time feedback to the ongoing neural activity recorded with HDMEA platforms. The potentiality of modern heterogeneous FPGAs has been exploited to realize the system. In particular, the Xilinx Zynq All Programmable System on Chip (APSoC) has been used. The device features reconfigurable logic, specialized hardwired blocks, and a dual-core ARM-based processor; the synergy of these components allows to achieve high elaboration performances while maintaining a high level of flexibility and adaptivity. The developed system has been embedded in an acquisition and stimulation setup featuring the following platforms: \u2022 3\ub7Brain BioCam X, a state-of-the-art HDMEA-based acquisition platform capable of recording in parallel from 4096 electrodes at 18 kHz per electrode. \u2022 PlexStim\u2122 Electrical Stimulator System, able to generate electrical stimuli with custom waveforms to 16 different output channels. \u2022 Texas Instruments DLP\uae LightCrafter\u2122 Evaluation Module, capable of projecting 608x684 pixels images with a refresh rate of 60 Hz; it holds the function of optical stimulation. All the features of the system, such as band-pass filtering and spike detection of all the recorded channels, have been validated by means of ex vivo experiments. Very low-latency has been achieved while processing the whole input data stream in real-time. In the case of electrical stimulation the total latency is below 2 ms; when optical stimuli are needed, instead, the total latency is a little higher, being 21 ms in the worst case. The final setup is ready to be used to infer cellular properties by means of closed-loop experiments. As a proof of this concept, it has been successfully used for the clustering and classification of retinal ganglion cells (RGCs) in mice retina. For this experiment, the light-evoked spikes from thousands of RGCs have been correctly recorded and analyzed in real-time. Around 90% of the total clusters have been classified as ON- or OFF-type cells. In addition to the closed-loop system, a denoising prototype has been developed. The main idea is to exploit oversampling techniques to reduce the thermal noise recorded by HDMEAbased acquisition systems. The prototype is capable of processing in real-time all the input signals from the BioCam X, and it is currently being tested to evaluate the performance in terms of signal-to-noise-ratio improvement

Design for energy-efficient and reliable fog-assisted healthcare IoT systems

Cardiovascular disease and diabetes are two of the most dangerous diseases as they are the leading causes of death in all ages. Unfortunately, they cannot be completely cured with the current knowledge and existing technologies. However, they can be effectively managed by applying methods of continuous health monitoring. Nonetheless, it is difficult to achieve a high quality of healthcare with the current health monitoring systems which often have several limitations such as non-mobility support, energy inefficiency, and an insufficiency of advanced services. Therefore, this thesis presents a Fog computing approach focusing on four main tracks, and proposes it as a solution to the existing limitations. In the first track, the main goal is to introduce Fog computing and Fog services into remote health monitoring systems in order to enhance the quality of healthcare. In the second track, a Fog approach providing mobility support in a real-time health monitoring IoT system is proposed. The handover mechanism run by Fog-assisted smart gateways helps to maintain the connection between sensor nodes and the gateways with a minimized latency. Results show that the handover latency of the proposed Fog approach is 10%-50% less than other state-of-the-art mobility support approaches. In the third track, the designs of four energy-efficient health monitoring IoT systems are discussed and developed. Each energy-efficient system and its sensor nodes are designed to serve a specific purpose such as glucose monitoring, ECG monitoring, or fall detection; with the exception of the fourth system which is an advanced and combined system for simultaneously monitoring many diseases such as diabetes and cardiovascular disease. Results show that these sensor nodes can continuously work, depending on the application, up to 70-155 hours when using a 1000 mAh lithium battery. The fourth track mentioned above, provides a Fog-assisted remote health monitoring IoT system for diabetic patients with cardiovascular disease. Via several proposed algorithms such as QT interval extraction, activity status categorization, and fall detection algorithms, the system can process data and detect abnormalities in real-time. Results show that the proposed system using Fog services is a promising approach for improving the treatment of diabetic patients with cardiovascular disease

Body of Knowledge for Graphics Processing Units (GPUs)

Graphics Processing Units (GPU) have emerged as a proven technology that enables high performance computing and parallel processing in a small form factor. GPUs enhance the traditional computer paradigm by permitting acceleration of complex mathematics and providing the capability to perform weighted calculations, such as those in artificial intelligence systems. Despite the performance enhancements provided by this type of microprocessor, there exist tradeoffs in regards to reliability and radiation susceptibility, which may impact mission success. This report provides an insight into GPU architecture and its potential applications in space and other similar markets. It also discusses reliability, qualification, and radiation considerations for testing GPUs

Towards end-to-end security in internet of things based healthcare

Healthcare IoT systems are distinguished in that they are designed to serve human beings, which primarily raises the requirements of security, privacy, and reliability. Such systems have to provide real-time notifications and responses concerning the status of patients. Physicians, patients, and other caregivers demand a reliable system in which the results are accurate and timely, and the service is reliable and secure. To guarantee these requirements, the smart components in the system require a secure and efficient end-to-end communication method between the end-points (e.g., patients, caregivers, and medical sensors) of a healthcare IoT system. The main challenge faced by the existing security solutions is a lack of secure end-to-end communication. This thesis addresses this challenge by presenting a novel end-to-end security solution enabling end-points to securely and efficiently communicate with each other. The proposed solution meets the security requirements of a wide range of healthcare IoT systems while minimizing the overall hardware overhead of end-to-end communication. End-to-end communication is enabled by the holistic integration of the following contributions. The first contribution is the implementation of two architectures for remote monitoring of bio-signals. The first architecture is based on a low power IEEE 802.15.4 protocol known as ZigBee. It consists of a set of sensor nodes to read data from various medical sensors, process the data, and send them wirelessly over ZigBee to a server node. The second architecture implements on an IP-based wireless sensor network, using IEEE 802.11 Wireless Local Area Network (WLAN). The system consists of a IEEE 802.11 based sensor module to access bio-signals from patients and send them over to a remote server. In both architectures, the server node collects the health data from several client nodes and updates a remote database. The remote webserver accesses the database and updates the webpage in real-time, which can be accessed remotely. The second contribution is a novel secure mutual authentication scheme for Radio Frequency Identification (RFID) implant systems. The proposed scheme relies on the elliptic curve cryptography and the D-Quark lightweight hash design. The scheme consists of three main phases: (1) reader authentication and verification, (2) tag identification, and (3) tag verification. We show that among the existing public-key crypto-systems, elliptic curve is the optimal choice due to its small key size as well as its efficiency in computations. The D-Quark lightweight hash design has been tailored for resource-constrained devices. The third contribution is proposing a low-latency and secure cryptographic keys generation approach based on Electrocardiogram (ECG) features. This is performed by taking advantage of the uniqueness and randomness properties of ECG's main features comprising of PR, RR, PP, QT, and ST intervals. This approach achieves low latency due to its reliance on reference-free ECG's main features that can be acquired in a short time. The approach is called Several ECG Features (SEF)-based cryptographic key generation. The fourth contribution is devising a novel secure and efficient end-to-end security scheme for mobility enabled healthcare IoT. The proposed scheme consists of: (1) a secure and efficient end-user authentication and authorization architecture based on the certificate based Datagram Transport Layer Security (DTLS) handshake protocol, (2) a secure end-to-end communication method based on DTLS session resumption, and (3) support for robust mobility based on interconnected smart gateways in the fog layer. Finally, the fifth and the last contribution is the analysis of the performance of the state-of-the-art end-to-end security solutions in healthcare IoT systems including our end-to-end security solution. In this regard, we first identify and present the essential requirements of robust security solutions for healthcare IoT systems. We then analyze the performance of the state-of-the-art end-to-end security solutions (including our scheme) by developing a prototype healthcare IoT system

Alternativas de proyecto e implementación de circuitos y de programas de reconstrucción tendientes a un tomografo por impedancia electrica para la presentación compacta del estado edemático de cortes torácicos en tiempo real

La tomografía por Impedancia Eléctrica es una técnica que permite estimar la distribución de conductividad dentro de un cuerpo en base a medidas en la superficie. Para alcanzar esta estimación se colocan electrodos en el cuerpo por los cuales se inyecta corriente y se miden diferencias de tensión. Con estas tensiones se llega a la distribución de conductividad mediante lo que se llama reconstrucción. El resultado es un corte tomográfico en donde los diferentes valores de conductividad son representados mediante diferentes colores. El núcleo de ingeniería biomédica de la Universidad de la República ha trabajado en esta técnica desde hace más de una década, llegando a un prototipo funcional denominado IMPETOM. Este prototipo fue muy valioso al momento de su culminación, pero para continuar con la línea de investigación era necesario realizar un rediseño. El objetivo de esta tesis es el diseño de un prototipo funcional de tomógrafo que permita, en tiempo real, el seguimiento de las funciones pulmonares y de las lesiones pulmonares agudas. El diseño propuesto cuenta con 16 electrodos que se colocan en una hilera, utilizando una cinta con velcro, sobre el tórax del paciente. Se inyecta corriente a una frecuencia de entre 20kHz y 100kHz mediante el método de electrodos adyacentes. Se utiliza demodulación digital para obtener los valores de tensión y pasar el vector de medidas a la PC donde se encuentra el software que realiza la reconstrucción. La reconstrucción de imágenes en la Tomografía por Impedancia Eléctrica es un problema inverso mal condicionado, por lo que pequeños errores y ruidos que se agreguen a las medidas provocan errores arbitrariamente grandes en la conductividad reconstruida. Para contrarrestar este mal condicionamiento nuestro diseño incluye la regularización del problema y el agregado de información a priori que garantiza que la reconstrucción esté dentro de un conjunto de soluciones esperadas. Existen varios métodos de regularización, la mayoría de los cuales limitan las soluciones a distribuciones regulares, mientras que otros métodos permiten que haya discontinuidades y saltos en la conductividad. En esta tesis se analizan y comparan varios de estos métodos y se determina cuál es el más adecuado para utilizar en el nuevo prototipo. Para la comparación se utilizaron datos simulados y datos reales tomados con el primer prototipo de IMPETOM

Measurement and correction of aberrations in light and electron microscopy

Imperfections in image formation, called aberrations, often preclude microscopes from reaching diffraction-limited resolution. Aberrations can be caused either by the microscope itself or by the sample and can be compensated for by using an active element integrated into the beam path which is functioning as a corrector. The optimal settings for this corrector need to be determined without excessive damage to the sample. In particular, for sensitive biological samples, the potential gain for signal and/or resolution needs to be weighed against sample damage. Here I present the development of a special type of optical coherence microscopy (called deep-OCM), which allows the precise determination of the average rat brain refractive index in vivo. The conclusion is that two-photon microscopy is affected by optical aberrations in this sample starting at depths around 200 micrometers. Deep-OCM is well suited for imaging myelinated nerve fibers. Individual fibers can be visualized in the living brain in unprecedented depths beyond 300 micrometers. In the second part of this thesis I describe the development and testing of an auto-focuser and auto-stigmator (called MAPFoSt) for a scanning electron microscope to ensure optimal imaging quality after switching samples or during long acquisition series. MAPFoSt determines the three focus and stigmation parameters from only two test images

Secure expandable communication framework for POCT system development and deployment

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonHealth-care delivery in developing countries has many challenges because they do not have enough resources for meeting the healthcare needs and they lack testing lab infras- tructures in communities. It has been proven that Point-Of-Care (POC) testing can be considered as one of the ways to resolve the crisis in healthcare delivery in these com- munities. The POC testing is a mission critical processes in which the patient conduct tests outside of laboratory environment and it needs a secure communication system of architecture support which the research refers as POCT system Almost every ten years there will be a new radio access technology (RAT) is released in the wireless communication system evolution which is primarily driven by the 3GPP standards organisation. It is challenging to develop a predictable communication sys- tem in an environment of frequent changes originated by the 3GPP and the wireless operators. The scalable and expandable network architecture is needed for cost-effective network management, deployment and operation of the POC devices. Security mecha- nisms are necessary to address the specific threats associated with POCT system. Se- curity mechanisms are necessary to address the specific threats associated with POCT system.The POCT system communication must provide secure storage and secure com- munication to maintain patient data privacy and security. The Federal Drug Admin- istration (FDA) reports the leading causes of defects and system failures in medical devices are caused by gaps between the requirements, implementation and testing. The research was conducted, and technical research contributions are made to resolve the issues and challenges related to the POCT system. A communication protocol implemented at the application level, independent of radio access technologies. A new methodology was created by combining Easy Approach to Requirement Specifications (EARS) methodology and Use Case Maps (UCM) model which is a new approach and it addresses the concerns raised by the FDA. Secure cloud architecture was created which is a new way of data storage and security algorithms models were designed to address the security threats in the POCT system. The security algorithms, secure cloud architecture and the communication protocol coexist together to provide Radio access technology Independent Secure and Expandable (RISE) POCT system. These are the contributions to new knowledge that came out of the research. The research was conducted with a team of experts who are the subject matter experts in the areas such as microfluidics, bio-medical, mechanical engineering and medicine