Unobtrusive Health Monitoring in Private Spaces: The Smart Vehicle

Unobtrusive in-vehicle health monitoring has the potential to use the driving time to perform regular medical check-ups. This work intends to provide a guide to currently proposed sensor systems for in-vehicle monitoring and to answer, in particular, the questions: (1) Which sensors are suitable for in-vehicle data collection? (2) Where should the sensors be placed? (3) Which biosignals or vital signs can be monitored in the vehicle? (4) Which purposes can be supported with the health data? We reviewed retrospective literature systematically and summarized the up-to-date research on leveraging sensor technology for unobtrusive in-vehicle health monitoring. PubMed, IEEE Xplore, and Scopus delivered 959 articles. We firstly screened titles and abstracts for relevance. Thereafter, we assessed the entire articles. Finally, 46 papers were included and analyzed. A guide is provided to the currently proposed sensor systems. Through this guide, potential sensor information can be derived from the biomedical data needed for respective purposes. The suggested locations for the corresponding sensors are also linked. Fifteen types of sensors were found. Driver-centered locations, such as steering wheel, car seat, and windscreen, are frequently used for mounting unobtrusive sensors, through which some typical biosignals like heart rate and respiration rate are measured. To date, most research focuses on sensor technology development, and most application-driven research aims at driving safety. Health-oriented research on the medical use of sensor-derived physiological parameters is still of interest

A phonocardiographic-based fiber-optic sensor and adaptive filtering system for noninvasive continuous fetal heart rate monitoring

This paper focuses on the design, realization, and verification of a novel phonocardiographic-based fiber-optic sensor and adaptive signal processing system for noninvasive continuous fetal heart rate (fHR) monitoring. Our proposed system utilizes two Mach-Zehnder interferometeric sensors. Based on the analysis of real measurement data, we developed a simplified dynamic model for the generation and distribution of heart sounds throughout the human body. Building on this signal model, we then designed, implemented, and verified our adaptive signal processing system by implementing two stochastic gradient-based algorithms: the Least Mean Square Algorithm (LMS), and the Normalized Least Mean Square (NLMS) Algorithm. With this system we were able to extract the fHR information from high quality fetal phonocardiograms (fPCGs), filtered from abdominal maternal phonocardiograms (mPCGs) by performing fPCG signal peak detection. Common signal processing methods such as linear filtering, signal subtraction, and others could not be used for this purpose as fPCG and mPCG signals share overlapping frequency spectra. The performance of the adaptive system was evaluated by using both qualitative (gynecological studies) and quantitative measures such as: Signal-to-Noise Ratio-SNR, Root Mean Square Error-RMSE, Sensitivity-S+, and Positive Predictive Value-PPV.Web of Science174art. no. 89

Application of advanced technology to space automation

Automated operations in space provide the key to optimized mission design and data acquisition at minimum cost for the future. The results of this study strongly accentuate this statement and should provide further incentive for immediate development of specific automtion technology as defined herein. Essential automation technology requirements were identified for future programs. The study was undertaken to address the future role of automation in the space program, the potential benefits to be derived, and the technology efforts that should be directed toward obtaining these benefits

A non-invasive multichannel hybrid fiber-optic sensor system for vital sign monitoring

In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG). The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS). The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person's chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field.Web of Science171art. no. 11

Wireless readout method for resonant sensors based on instantaneous frequency measurement

Drahtloses Erfassen verschiedener physikalischer Größen, wie Temperatur, Kraft und Drehmoment, ist bereits heute eine wichtige Aufgabe der industriellen Messtechnik und wird durch die fortschreitende Automatisierung auch in anderen Gebieten stetig relevanter. Einen vielversprechenden Ansatz stellen dafür resonante Hochfrequenz-Sensoren dar, beispielsweise basierend auf akustischen Oberflächenwellen (SAW-Sensoren). Diese rein passiven Sensoren sind extrem robust und können auch unter schwierigsten Umgebungsbedingungen eingesetzt werden. Bisher scheitern jedoch viele Anwendungen dieser zukunftsträchtigen Technologie an den aufwendigen und teuren Lesegeräten, die zum Abfragen der Sensoren benötigt werden. Die vorliegende Arbeit stellt deshalb ein neues drahtloses Ausleseverfahren für resonante Sensoren vor, bei dem erstmalig das Prinzip der instantanen Frequenzmessung (Augenblicksfrequenz- bzw. Momentanfrequenzmessung) verwendet wurde, um das Antwortsignal des Sensors auszuwerten. Durch diesen interferometrischen Ansatz lassen sich hohe Messwertaktualisierungsraten mit deutlich reduziertem Hardwareaufwand realisieren. Um Nichtidealitäten sowie Einflüsse von Temperatur und Alterungseffekte der analogen Hardwarekomponenten zu minimieren, wurde eine In-situ-Linearisierung verwendet, die bekannte Referenzsignale einspeist, um damit systematische Fehler in den nachfolgenden unbekannten Messungen digital zu kompensieren. Ein Kernpunkt dieser Arbeit stellt die detaillierte theoretische Untersuchung zur Systemauslegung sowie den Systemgrenzen und Fehlerkompensationsmöglichkeiten des vorgeschlagenen Verfahrens dar. Dazu wurden alle Einzelkomponenten inklusive möglicher Quereinflüsse im Gesamtsystemkontext evaluiert und neben internen Fehlerquellen auch externe Störeinflüsse betrachtet. Dabei wurden entscheidende neue Erkenntnisse für den praktischen Einsatz dieses innovativen Messkonzeptes erlangt, die sich zum Entwurf eines optimierten Gesamtsystems nutzen lassen. Um die Realisierbarkeit des Konzepts zu zeigen, wurden Laboruntersuchungen durchgeführt und ein Systemdemonstrator im 2,4-GHz-Frequenzband entworfen und evaluiert. Dieser konnte mit einfacher Schaltungstechnik eine 3-Sigma-Präzision der Frequenzmessung unter 2 Millionstel (ppm) bei 1000 Messungen pro Sekunde erreichen. Zusammen mit der unkomplizierten Signalverarbeitung werden dadurch neue Maßstäbe hinsichtlich kostengünstiger Realisierungsmöglichkeiten gesetzt und enormes Potential für verschiedene industrielle, automotive und medizinische Anwendungen demonstriert.Wireless acquisition of various physical quantities, such as temperature, force and torque, is already an important task in industrial metrology and is becoming more and more relevant in other areas as a result of the increasing automation. Resonant high-frequency sensors, for example based on surface acoustic waves (SAW sensors), are a promising approach. These purely passive sensors are extremely robust and can be used even under the most difficult environmental conditions. So far, however, many applications of this innovative technology cannot be realized due to the complex and expensive reading devices required to interrogate the sensors. The present work therefore presents a new wireless readout method for resonant high-frequency sensors, using the concept of instantaneous frequency measurement for the first time to evaluate the response signal of the sensor. This interferometric approach allows high measurement update rates with significantly reduced hardware requirements. In order to minimize non-idealities as well as influences of temperature and aging effects of the analog hardware components, an in-situ linearization was used which feeds known reference signals to digitally compensate systematic errors in the following unknown measurements. A core topic of this work is the detailed theoretical investigation of the system design as well as the system limits and error compensation possibilities of the proposed method. For this purpose, all individual components including possible cross-influences were evaluated in the overall system context and, besides internal error sources, external interferences were also considered. Thereby decisive new findings for the practical application of this innovative measuring concept were obtained which can be used for the design of an optimized overall system. In order to demonstrate the feasibility of the presented concept, laboratory investigations were performed and a system demonstrator in the 2.4 GHz frequency band was designed and evaluated. Using simple circuit technology, the system demonstrator was able to achieve a 3 sigma precision of the frequency measurement of less than 2 parts per million (ppm) at 1000 measurements per second. Together with the low complexity signal processing, this sets new standards in terms of cost-effective implementation possibilities and demonstrates huge potential for various industrial, automotive and medical applications

NASA Tech Briefs, November 2008

Topics covered include: Digital Phase Meter for a Laser Heterodyne Interferometer; Vision System Measures Motions of Robot and External Objects; Advanced Precipitation Radar Antenna to Measure Rainfall From Space; Wide-Band Radar for Measuring Thickness of Sea Ice; Vertical Isolation for Photodiodes in CMOS Imagers; Wide-Band Microwave Receivers Using Photonic Processing; L-Band Transmit/Receive Module for Phase-Stable Array Antennas; Microwave Power Combiner/Switch Utilizing a Faraday Rotator; Compact Low-Loss Planar Magic-T; Using Pipelined XNOR Logic to Reduce SEU Risks in State Machines; Quasi-Optical Transmission Line for 94-GHz Radar; Next Generation Flight Controller Trainer System; Converting from DDOR SASF to APF; Converting from CVF to AAF; Documenting AUTOGEN and APGEN Model Files; Sequence History Update Tool; Extraction and Analysis of Display Data; MRO DKF Post-Processing Tool; Rig Diagnostic Tools; MRO Sequence Checking Tool; Science Activity Planner for the MER Mission; UAVSAR Flight-Planning System; Templates for Deposition of Microscopic Pointed Structures; Adjustable Membrane Mirrors Incorporating G-Elastomers; Hall-Effect Thruster Utilizing Bismuth as Propellant; High-Temperature Crystal-Growth Cartridge Tubes Made by VPS; Quench Crucibles Reinforced with Metal; Deep-Sea Hydrothermal-Vent Sampler; Mars Rocket Propulsion System; Two-Stage Passive Vibration Isolator; Improved Thermal Design of a Compression Mold; Enhanced Pseudo-Waypoint Guidance for Spacecraft Maneuvers; Altimetry Using GPS-Reflection/Occultation Interferometry; Thermally Driven Josephson Effect; Perturbation Effects on a Supercritical C7H16/N2 Mixing Layer; Gold Nanoparticle Labels Amplify Ellipsometric Signals; Phase Matching of Diverse Modes in a WGM Resonator; WGM Resonators for Terahertz-to-Optical Frequency Conversion; Determining Concentration of Nanoparticles from Ellipsometry; Microwave-to-Optical Conversion in WGM Resonators; Four-Pass Coupler for Laser-Diode-Pumped Solid-State Laser; Low-Resolution Raman-Spectroscopy Combustion Thermometry; Temperature Sensors Based on WGM Optical Resonators; Varying the Divergence of Multiple Parallel Laser Beams; Efficient Algorithm for Rectangular Spiral Search; Algorithm-Based Fault Tolerance Integrated with Replication; Targeting and Localization for Mars Rover Operations; Terrain-Adaptive Navigation Architecture; Self-Adjusting Hash Tables for Embedded Flight Applications; Schema for Spacecraft-Command Dictionary; Combined GMSK Communications and PN Ranging; System-Level Integration of Mass Memory; Network-Attached Solid-State Recorder Architecture; Method of Cross-Linking Aerogels Using a One-Pot Reaction Scheme; An Efficient Reachability Analysis Algorithm

PATTERN RECOGNITION INTEGRATED SENSING METHODOLOGIES (PRISMS) IN PHARMACEUTICAL PROCESS VALIDATION, REMOTE SENSING AND ASTROBIOLOGY

Modern analytical instrumentation is capable of creating enormous and complex volumes of data. Analysis of large data volumes are complicated by lengthy analysis time and high computational demand. Incorporating real-time analysis methods that are computationally efficient are desirable for modern analytical methods to be fully utilized. The use of modern instrumentation in on-line pharmaceutical process validation, remote sensing, and astrobiology applications requires real-time analysis methods that are computationally efficient. Integrated sensing and processing (ISP) is a method for minimizing the data burden and sensing time of a system. ISP is accomplished through implementation of chemometric calculations in the physics of the spectroscopic sensor itself. In ISP, the measurements collected at the detector are weighted to directly correlate to the sample properties of interest. This method is especially useful for large and complex data sets. In this research, ISP is applied to acoustic resonance spectroscopy, near-infrared hyperspectral imaging and a novel solid state spectral imager. In each application ISP produced a clear advantage over the traditional sensing method. The limitations of ISP must be addressed before it can become widely used. ISP is essentially a pattern recognition algorithm. Problems arise in pattern recognition when the pattern-recognition algorithm encounters a sample unlike any in the original calibration set. This is termed the false sample problem. To address the false sample problem the Bootstrap Error-Adjusted Single-Sample Technique (BEST, a nonparametric classification technique) was investigated. The BEST-ISP method utilizes a hashtable of normalized BEST points along an asymmetric probability density contour to estimate the BEST multidimensional standard deviation of a sample. The on-line application of the BEST method requires significantly less computation than the full algorithm allowing it to be utilized in real time as sample data is obtained. This research tests the hypothesis that a BEST-ISP metric can be used to detect false samples with sensitivity \u3e 90% and specificity \u3e 90% on categorical data

The Telecommunications and Data Acquisition Progress Report 42-77

Activities in space communication, radio navigation, radio science, and ground-based astronomy are reported. Advanced systems for the Deep Space Network and its Ground-Communications Facility are discussed including station control and system technology. Network sustaining as well as data and information systems are covered. Studies of geodynamics, investigations of the microwave spectrum, and the search for extraterrestrial intelligence are reported

Optical Switching for Scalable Data Centre Networks

This thesis explores the use of wavelength tuneable transmitters and control systems within the context of scalable, optically switched data centre networks. Modern data centres require innovative networking solutions to meet their growing power, bandwidth, and scalability requirements. Wavelength routed optical burst switching (WROBS) can meet these demands by applying agile wavelength tuneable transmitters at the edge of a passive network fabric. Through experimental investigation of an example WROBS network, the transmitter is shown to determine system performance, and must support ultra-fast switching as well as power efficient transmission. This thesis describes an intelligent optical transmitter capable of wideband sub-nanosecond wavelength switching and low-loss modulation. A regression optimiser is introduced that applies frequency-domain feedback to automatically enable fast tuneable laser reconfiguration. Through simulation and experiment, the optimised laser is shown to support 122×50 GHz channels, switching in less than 10 ns. The laser is deployed as a component within a new wavelength tuneable source (WTS) composed of two time-interleaved tuneable lasers and two semiconductor optical amplifiers. Switching over 6.05 THz is demonstrated, with stable switch times of 547 ps, a record result. The WTS scales well in terms of chip-space and bandwidth, constituting the first demonstration of scalable, sub-nanosecond optical switching. The power efficiency of the intelligent optical transmitter is further improved by introduction of a novel low-loss split-carrier modulator. The design is evaluated using 112 Gb/s/λ intensity modulated, direct-detection signals and a single-ended photodiode receiver. The split-carrier transmitter is shown to achieve hard decision forward error correction ready performance after 2 km of transmission using a laser output power of just 0 dBm; a 5.2 dB improvement over the conventional transmitter. The results achieved in the course of this research allow for ultra-fast, wideband, intelligent optical transmitters that can be applied in the design of all-optical data centres for power efficient, scalable networking