A high performance LIA-based interface for battery powered sensing devices

This paper proposes a battery-compatible electronic interface based on a general purpose lock-in amplifier (LIA) capable of recovering input signals up to the MHz range. The core is a novel ASIC fabricated in 1.8 V 0.18 µm CMOS technology, which contains a dual-phase analog lock-in amplifier consisting of carefully designed building blocks to allow configurability over a wide frequency range while maintaining low power consumption. It operates using square input signals. Hence, for battery-operated microcontrolled systems, where square reference and exciting signals can be generated by the embedded microcontroller, the system benefits from intrinsic advantages such as simplicity, versatility and reduction in power and size. Experimental results confirm the signal recovery capability with signal-to-noise power ratios down to -39 dB with relative errors below 0.07% up to 1 MHz. Furthermore, the system has been successfully tested measuring the response of a microcantilever-based resonant sensor, achieving similar results with better power-bandwidth trade-off compared to other LIAs based on commercial off-the-shelf (COTS) components and commercial LIA equipment

A WIRELESS SENSOR NETWORK BOARD FOR ENVIRONMENTAL MONITORING USING GNSS AND ANALOG TRIAXIAL ACCELEROMETER

Wireless Sensor Networks (WSNs) have attracted an increasing attention in recent years because of the large number of potential applications. They are used for collecting, storing and sharing data, for monitoring applications, surveillance purposes and much more. On the other hand GNSSs are used in various systems devoted to monitor different atmospheric parameters and to trace displacements of landslides and glaciers in severe environmental conditions and in all weather situations. A first example of low cost DGPS wireless sensor network was installed in 2009 on a serac located at 4100 m above a populated area in the Aosta Valley, Italy, and it is still operative. This work presents an evolution of the WSN node used in that systems with improved functionalities and flexibility. The electronic board developed as a multipurpose board to be used in different WSNs, has been completely redesigned as an open system in order to reduce its sizes and to be configured by only varying the firmware on the microcontroller. It allows different interfaces and is equipped with a recovery system, guaranteed by a watchdog chip which continuously monitor the onboard microcontroller. The board is equipped with both a GNSS module and an analog triaxial accelerometer in order to merge GNSS raw data and accelerometer data to keep track of both fast events and slow events. A free open source operative system has been ported on the microcontroller in order to perform multiple operations and to manage the communications between the network nodes with improved efficiency. The board firmware can be modified in real time using a custom bootloader to avoid difficult maintenance operations

Configurable 3D-integrated focal-plane sensor-processor array architecture

A mixed-signal Cellular Visual Microprocessor architecture with digital processors is described. An ASIC implementation is also demonstrated. The architecture is composed of a regular sensor readout circuit array, prepared for 3D face-to-face type integration, and one or several cascaded array of mainly identical (SIMD) processing elements. The individual array elements derived from the same general HDL description and could be of different in size, aspect ratio, and computing resources

Bioimpedance Technique for Point-of-Care Devices Relying on Disposable Label-Free Sensors – An Anemia Detection Case

In this chapter, the development of a point-of-care device for bio-medical applications has been discussed. Our main objective is to research new electronic solutions for the detection, quantification, and monitoring of important biological agents in medical environments. The proposed systems and technologies rely on label-free disposable sensors, with portable electronics for user-friendly, low-cost solutions for medical disease diagnosis, monitoring, and treatment. In this chapter, we will focus on a specific point-of-care device for cellular analysis, applied to the case of anemia detection and monitoring. The methodology used for anemia monitoring is based on hematocrit measurement directly from whole blood samples by means of impedance analysis. The designed device is based on straightforward electronic standards for low power consumption and low-cost disposable sensor for low volume samples, resulting in a robust and low power consumption device for portable monitoring purposes of anemia. The device has been validated through different whole blood samples to prove the response, effectiveness, and robustness to detect anemia

Low cost attitude control system scanwheel development

In order to satisfy a growing demand for low cost attitude control systems for small spacecraft, development of low cost scanning horizon sensor coupled to a low cost/low power consumption Reaction Wheel Assembly was initiated. This report addresses the details of the versatile design resulting from this effort. Tradeoff analyses for each of the major components are included, as well as test data from an engineering prototype of the hardware

Evolvable Smartphone-Based Point-of-Care Systems For In-Vitro Diagnostics

Recent developments in the life-science -omics disciplines, together with advances in micro and nanoscale technologies offer unprecedented opportunities to tackle some of the major healthcare challenges of our time. Lab-on-Chip technologies coupled with smart-devices in particular, constitute key enablers for the decentralization of many in-vitro medical diagnostics applications to the point-of-care, supporting the advent of a preventive and personalized medicine. Although the technical feasibility and the potential of Lab-on-Chip/smart-device systems is repeatedly demonstrated, direct-to-consumer applications remain scarce. This thesis addresses this limitation. System evolvability is a key enabler to the adoption and long-lasting success of next generation point-of-care systems by favoring the integration of new technologies, streamlining the reengineering efforts for system upgrades and limiting the risk of premature system obsolescence. Among possible implementation strategies, platform-based design stands as a particularly suitable entry point. One necessary condition, is for change-absorbing and change-enabling mechanisms to be incorporated in the platform architecture at initial design-time. Important considerations arise as to where in Lab-on-Chip/smart-device platforms can these mechanisms be integrated, and how to implement them. Our investigation revolves around the silicon-nanowire biological field effect transistor, a promising biosensing technology for the detection of biological analytes at ultra low concentrations. We discuss extensively the sensitivity and instrumentation requirements set by the technology before we present the design and implementation of an evolvable smartphone-based platform capable of interfacing lab-on-chips embedding such sensors. We elaborate on the implementation of various architectural patterns throughout the platform and present how these facilitated the evolution of the system towards one accommodating for electrochemical sensing. Model-based development was undertaken throughout the engineering process. A formal SysML system model fed our evolvability assessment process. We introduce, in particular, a model-based methodology enabling the evaluation of modular scalability: the ability of a system to scale the current value of one of its specification by successively reengineering targeted system modules. The research work presented in this thesis provides a roadmap for the development of evolvable point-of-care systems, including those targeting direct-to-consumer applications. It extends from the early identification of anticipated change, to the assessment of the ability of a system to accommodate for these changes. Our research should thus interest industrials eager not only to disrupt, but also to last in a shifting socio-technical paradigm

Wide-band compact 1.8 V-0.18 µm CMOS analog front-end for impedance spectroscopy

In this letter, a fully integrated configurable front-end for Impedance Spectroscopy (IS) is presented. The circuit includes fully differential in-phase and quadrature channels, using a transconductor (TC)-transimpedance (TI) approach. The input TC, shared for both channels, is based on a programmable degenerated differential pair to attain low-noise programmable-gain, while identical TII/Q with embedded synchronous rectification provide both I, Q outputs, filtered through fc adjustable Gm-C integrators. It exhibits a programmable gain ranging from 0 dB to 40 dB with 87 MHz bandwidth, amplitude and phase recovery errors below 1.9% and 2.5∘ respectively and an input referred noise floor of 16.7 nV/Hz. The result is a high-performance very compact topology with a total power consumption of 292 μW at a 1.8 V power supply, thus constituting an appropriate solution for full on chip multichannel IS systems

Electromagnetic signal injection attacks on embedded systems: modeling and detection

Embedded systems are ubiquitous in our lives, from smart locks in home automation to robotic arms in industrial equipment, playing key roles in many safety- and security-critical applications. An embedded system can interact with the external world through three interfaces: it uses sensors to sense environmental changes, controls actuators to cause physical impacts, and exchanges information with others through transmission lines. In recent years, studies have demonstrated using electromagnetic interference (EMI) to wirelessly manipulate signals in these interfaces. Such manipulation can maliciously control the embedded systems, threatening users' privacy and safety, for example, unlocking a smart lock or raising the temperature of infant incubators. Detecting such attacks is becoming increasingly essential, but proposed detection methods in the literature are designed for specific applications. Thus, this thesis proposes two novel detection methods that can protect various systems regardless of their types, filling the gap of generalized detection methods. The first detection method is for the sensors, and its core idea is to modulate the sensor power in a secret pattern unknown to the attacker. To bypass the detection, the attacker must guess the secret correctly; however, this detection method provides a strong security guarantee, where the probability of a correct guess is negligible. The second detection method is designed for the actuators, and its detection principle is to compare a signal to be protected with a reference, between which the difference can indicate whether an attack occurs. This method can guarantee that any attack effectively impacting a victim system will be detected. This thesis will demonstrate that these detection methods do not only provide strong security guarantees but are also lightweight and flexible to be integrated with different systems. In addition to these detection methods, this thesis presents a pioneering study about how to corrupt the signal integrity of differential signaling. Since many popular protocols such as USB, Ethernet, HDMI, and CAN derive their electromagnetic noise immunity from differential signaling, many people believe it can make communications immune to external interference, whereas the study challenges this assumption and shows a state-of-the-art attack that allows an attacker to use fine-tuned EMI to inject arbitrary messages into differential signaling

Embedded System development with PSOC : orientation sensing and visualization with PSOC

This thesis describes a new embedded system development process. The thesis aims to demonstrate how embedded systems could be developed efficiently with the help of the new technological advances such as programmable systems on chips. A special focus is given on HW and SW programming of such systems. The project makes use of a new generation of a chip called Programmable System on Chip (PSoC) as its hardware platform. What distinguishes PSoC from a line of processors and system on chips is its programmable hardware. This feature allows embedded system designers to be able to customize part of the hardware programmatically in addition to writing a software application that runs on top of the system. This thesis introduces the development of an embedded system based on the PSoc chip and development environment provided by Cypress semiconductors. Finally, this thesis presents a position sensing application which demonstrates the development process of a modern day typical embedded system