Motion Artifact Processing Techniques for Physiological Signals

The combination of reducing birth rate and increasing life expectancy continues to drive the demographic shift toward an ageing population and this is placing an ever-increasing burden on our healthcare systems. The urgent need to address this so called healthcare \time bomb" has led to a rapid growth in research into ubiquitous, pervasive and distributed healthcare technologies where recent advances in signal acquisition, data storage and communication are helping such systems become a reality. However, similar to recordings performed in the hospital environment, artifacts continue to be a major issue for these systems. The magnitude and frequency of artifacts can vary signicantly depending on the recording environment with one of the major contributions due to the motion of the subject or the recording transducer. As such, this thesis addresses the challenges of the removal of this motion artifact removal from various physiological signals. The preliminary investigations focus on artifact identication and the tagging of physiological signals streams with measures of signal quality. A new method for quantifying signal quality is developed based on the use of inexpensive accelerometers which facilitates the appropriate use of artifact processing methods as needed. These artifact processing methods are thoroughly examined as part of a comprehensive review of the most commonly applicable methods. This review forms the basis for the comparative studies subsequently presented. Then, a simple but novel experimental methodology for the comparison of artifact processing techniques is proposed, designed and tested for algorithm evaluation. The method is demonstrated to be highly eective for the type of artifact challenges common in a connected health setting, particularly those concerned with brain activity monitoring. This research primarily focuses on applying the techniques to functional near infrared spectroscopy (fNIRS) and electroencephalography (EEG) data due to their high susceptibility to contamination by subject motion related artifact. Using the novel experimental methodology, complemented with simulated data, a comprehensive comparison of a range of artifact processing methods is conducted, allowing the identication of the set of the best performing methods. A novel artifact removal technique is also developed, namely ensemble empirical mode decomposition with canonical correlation analysis (EEMD-CCA), which provides the best results when applied on fNIRS data under particular conditions. Four of the best performing techniques were then tested on real ambulatory EEG data contaminated with movement artifacts comparable to those observed during in-home monitoring. It was determined that when analysing EEG data, the Wiener lter is consistently the best performing artifact removal technique. However, when employing the fNIRS data, the best technique depends on a number of factors including: 1) the availability of a reference signal and 2) whether or not the form of the artifact is known. It is envisaged that the use of physiological signal monitoring for patient healthcare will grow signicantly over the next number of decades and it is hoped that this thesis will aid in the progression and development of artifact removal techniques capable of supporting this growth

Remote Sensing for Precision Nitrogen Management

This book focuses on the fundamental and applied research of the non-destructive estimation and diagnosis of crop leaf and plant nitrogen status and in-season nitrogen management strategies based on leaf sensors, proximal canopy sensors, unmanned aerial vehicle remote sensing, manned aerial remote sensing and satellite remote sensing technologies. Statistical and machine learning methods are used to predict plant-nitrogen-related parameters with sensor data or sensor data together with soil, landscape, weather and/or management information. Different sensing technologies or different modelling approaches are compared and evaluated. Strategies are developed to use crop sensing data for in-season nitrogen recommendations to improve nitrogen use efficiency and protect the environment

The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Final Report

The Habitable Exoplanet Observatory, or HabEx, has been designed to be the Great Observatory of the 2030s. For the first time in human history, technologies have matured sufficiently to enable an affordable space-based telescope mission capable of discovering and characterizing Earthlike planets orbiting nearby bright sunlike stars in order to search for signs of habitability and biosignatures. Such a mission can also be equipped with instrumentation that will enable broad and exciting general astrophysics and planetary science not possible from current or planned facilities. HabEx is a space telescope with unique imaging and multi-object spectroscopic capabilities at wavelengths ranging from ultraviolet (UV) to near-IR. These capabilities allow for a broad suite of compelling science that cuts across the entire NASA astrophysics portfolio. HabEx has three primary science goals: (1) Seek out nearby worlds and explore their habitability; (2) Map out nearby planetary systems and understand the diversity of the worlds they contain; (3) Enable new explorations of astrophysical systems from our own solar system to external galaxies by extending our reach in the UV through near-IR. This Great Observatory science will be selected through a competed GO program, and will account for about 50% of the HabEx primary mission. The preferred HabEx architecture is a 4m, monolithic, off-axis telescope that is diffraction-limited at 0.4 microns and is in an L2 orbit. HabEx employs two starlight suppression systems: a coronagraph and a starshade, each with their own dedicated instrument

The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Final Report

The Habitable Exoplanet Observatory, or HabEx, has been designed to be the Great Observatory of the 2030s. For the first time in human history, technologies have matured sufficiently to enable an affordable space-based telescope mission capable of discovering and characterizing Earthlike planets orbiting nearby bright sunlike stars in order to search for signs of habitability and biosignatures. Such a mission can also be equipped with instrumentation that will enable broad and exciting general astrophysics and planetary science not possible from current or planned facilities. HabEx is a space telescope with unique imaging and multi-object spectroscopic capabilities at wavelengths ranging from ultraviolet (UV) to near-IR. These capabilities allow for a broad suite of compelling science that cuts across the entire NASA astrophysics portfolio. HabEx has three primary science goals: (1) Seek out nearby worlds and explore their habitability; (2) Map out nearby planetary systems and understand the diversity of the worlds they contain; (3) Enable new explorations of astrophysical systems from our own solar system to external galaxies by extending our reach in the UV through near-IR. This Great Observatory science will be selected through a competed GO program, and will account for about 50% of the HabEx primary mission. The preferred HabEx architecture is a 4m, monolithic, off-axis telescope that is diffraction-limited at 0.4 microns and is in an L2 orbit. HabEx employs two starlight suppression systems: a coronagraph and a starshade, each with their own dedicated instrument.Comment: Full report: 498 pages. Executive Summary: 14 pages. More information about HabEx can be found here: https://www.jpl.nasa.gov/habex

Exploratory Data Analysis

In the Food research and production field, system complexity is increasing and several new challenges are emerging every day. This implies a urgent necessity to extract information and obtain models capable of inferring the underlying relationships that link all the variability sources which characterize food or its production process (e.g. compositional profile, processing conditions) to very general end-properties of foodstuff, such as the healthiness, the consumer perception, the link to a territory and the effect of the production chain itself on food. This makes a \u201cdeductive\u201d, theory-driven research approach inefficient, since it is often difficult to formulate hypotheses. Explorative Multivariate Data Analysis methods, together with the most recent analytical instrumentation, offer the possibility to come back to an \u201cinductive\u201d data-driven attitude with a minimum of a priori hypotheses, instead helping in formulating new ones from the direct observation of data. The aim of this Chapter is to offer the reader an overview of the most significant tools which can be used in a preliminary, exploratory phase, ranging from the most classical descriptive statistics methods, to Multivariate Analysis methods, with particular attention to Projection methods. For all techniques, examples are given so that the main advantage of this techniques, that is a direct, graphical representation of data and their characteristics, can be immediately experienced by the reader

Exploiting Photoisomerization: Spectroscopy on a Carotenoid Sensor and Retinal Proteins

Light-based methodologies enjoy popularity due to their non-invasive nature. In particular in the field of optogenetics, where genetic targeting of neurons permits not only simultaneous imaging of a large number of cells but also optical control of neuronal activity. For this, ion channels or pumps are inserted into the membrane which are activated by light. A deep biophysical understanding of the optogenetic systems is key for their successful application. In this thesis, I present a new member in the family of organic voltage sensors. I demonstrate that in a single lipid bilayer environment, the carotenoid Zeaxanthin has a linear and reversible spectral Raman response to an electric field applied across the membrane. The underlying mechanism is an increased photoisomerization rate resulting in a higher 13-cis population which is detected via a characteristic vibrational band at 1130 cm−1. Channelrhodopsin-2 (ChR2) is a frequently used protein in optogenetics to silence neuronal activity. By variation of amino acid side chains, we found experimental evidence for ground-state heterogeneity in the hydrogen bond interactions of the retinal protonated Schiff base (PSB). We have identified with Raman spectroscopy two spectral components of the C=N–H mode of the PSB at 1661 and 1665 cm−1, representing hydrogen bonds to different amino acid side chains. These two interactions of the PSB could be essential for a voltage-sensing mechanism in ChR2. In a pioneering approach we combined time-resolved absorption spectroscopy with serial femtosecond X-ray crystallography to scrutinize mechanistic details of sodium pumping in Krokinobacter eikastus rhodopsin 2 (KR2). Using an infrared-emitting quantum cascade laser (QCL), we verified that crystalline KR2 exhibits reaction kinetics similar to those observed in its detergent solubilized form. Hereupon, we have identified a previously proposed transient sodium binding site during the O intermediate where the sodium is coordinated by the amino acid side chains of N112 and D251. The findings regarding the ion transport mechanism in KR2 will facilitate the design of protein variants for an optogenetic application. Bistable G-protein coupled receptors (GPCRs) have two thermally stable conformations and are a promising class of rhodopsins which have the potential to serve as an optogenetic switch. We were able to conduct a first biophysical characterization of the invertebrate jumping spider rhodopsin-1 (JSR1). We propose a model of the two-photon reaction based on spectroscopic results. During these reactions, the Schiff base stays protonated implying that a deprotonation is not a prerequisite for the function of bistable GPCRs. A proposed mediating water molecule as part of the counterion complex in the inactive conformation is identified by Raman spectroscopy and later confirmed by an X-ray crystallographic structure. In conclusion, this thesis provides insights into the mechanistic details of established and upcoming optogenetic tools. These results will help to adapt their biophysical properties better suiting the needs of application.Lichtbasierende Methoden erfreuen sich aufgrund ihrer nicht-invasiven Eigenschaft großer Beliebtheit. Im Besonderen in der Optogenetik, wo Neuronen genetisch modifiziert werden um nicht nur die simultane Beobachtung einer großen Anzahl von Neuronen, sondern auch optische Kontrolle von neuronaler Aktivität zu ermöglichen. Hierzu werden Ionenkanäle oder -pumpen in die Membran gebracht, die durch Licht aktiviert werden können. Ein tiefes Verständnis von optogenetischen Systemen ist eine Schlüsselvoraussetzung für eine erfolgreiche Anwendung. In dieser Arbeit präsentiere ich einen Neuzugang in die Familie der organischen Spannungssensoren. Ich demonstriere, dass das Karotenoid Zeaxanthin, eingebracht in eine einzelne Lipiddoppelschicht, eine lineare und reversible Reaktion zeigt, wenn ein elektrisches Feld über die Membran angelegt wird. Der zugrunde liegende Mechanismus ist eine größere Population an 13-cis Isomeren, hervorgerufen durch eine erhöhte Photoisomerationsrate. Dies führt zu einem Anwachsen einer charakteristischen Vibrationsbande bei 1130 cm−1. Kanalrhodopsin-2 (ChR2) wird regelmäßig in der Optogentik genutzt um neuronale Aktivität zu verhindern. Durch Variation von Aminosäurenseitenketten liefern wir Beweise für eine Heterogenität in der Wasserstoffbrückeninteraktion der protonierten Schiffschen Base (PSB) im Grundzustand. Wir konnten mit Raman Spektroskopie zwei spektrale Komponenten in der PSB Vibrationsmode (C=N–H) bei 1661 und 1665 cm−1 identifizieren, die jeweils eine Wasserstoffbrücke zu einer anderen Aminosäurenseitenkette darstellen. Diese zwei Interaktionen könnten von Bedeutung für einen Spannungsmessungsmechanismus in ChR2 sein. Um den Natriumpumpmechanismus von Krokinobacter eikastus rhodopsin 2 (KR2) zu untersuchen, haben wir in einer Pionierarbeit zeitaufgelöste Absorbtionspektroskopie mit Röntgenkristallographie kombiniert. Die Benutzung eines Quantumkaskadenlasers (QCL) ermöglichte es uns sicher zu stellen, dass kristallines KR2 vergleichbare Reaktionskinetiken aufweist als in Detergens gelost. Wir konnten daraufhin eine im Vorfeld postulierte vorübergehende Natriumbindungsstelle während des O Intermediats zwischen den Seitenketten von N112 und D251 identifizieren. Die Ergebnisse über den Ionentransportmechanismus werden die Konzipierung von Proteinvarianten für eine optogenetische Anwendung erleichtern. Bistabile G-Protein-gekoppelte Rezeptoren (GPCRs) haben zwei thermisch stabile Konformationen und sind eine vielversprechende Klasse von Rhodopsinen für einen optogentischen Schalter. Wir konnten eine erste biophysikalische Charakterisierung von jumping spider rhodopsin-1 (JSR1) durchführen. Wir schlagen, basierend auf spektroskopischen Ergebnissen, ein Model einer zwei-Photonen Reaktion vor. Während dieser Reaktionen bleibt die SB protoniert. Dies impliziert, dass eine Deprotonierung keine Voraussetzung für die Funktion von bistabilen GPCRs ist. Ein angenommenes Wassermolekül als Teil des Konterionennetzwerks konnte mit Raman Spektroskopie detektiert werden, was später durch eine Röntgenstruktur bestätigt wurde. Zusammenfassend bietet diese Arbeit Einblicke in die Mechanismen von etablierten sowie neuen optogenetischen Werkzeugen. Die Resultate werden dazu beitragen, ihre biophysikalischen Eigenschaften an die Erfordernisse der Anwendung anzupassen

Principal Component Analysis

This book is aimed at raising awareness of researchers, scientists and engineers on the benefits of Principal Component Analysis (PCA) in data analysis. In this book, the reader will find the applications of PCA in fields such as image processing, biometric, face recognition and speech processing. It also includes the core concepts and the state-of-the-art methods in data analysis and feature extraction

METHANE AND OTHER UNLIKELY LIGANDS: AN NMR STUDY OF ALKANE σ-COMPLEXES

This thesis discusses the binding of alkanes (saturated hydrocarbons) to transition metal complexes. The thesis describes: (i) the first direct Nuclear Magnetic Resonance (NMR) spectroscopic observation of alkane coordination to group 8 transition metal centres; (ii) the only complete group of analogous transition metal alkane σ-complexes (Fe, Ru and Os); and (iii) the first set of methane σ-complexes, formed from molecular methane, that are sufficiently stable to analyse using NMR spectroscopy. Chapter 1 is a general introduction for the non-specialist, introducing the concepts of coordination chemistry and in particular the formation of σ-complexes including complexes of molecular hydrogen and alkanes. Chapter 2 contains an introduction to methane in organometallic chemistry and describes results from low temperature NMR spectroscopic and computational investigations into the methane σ-complexes [η5-CpM(CO)2(CH4)][Al(OC(CF3)3)4] (M = Os (5), Ru (13), Fe (17)) that were produced using an improved in situ NMR sample photolysis apparatus. The bound methane fragments in 5, 13 and 17 have 1H resonances at δ −2.16, δ −2.10 and δ −4.27; 13C resonances at δ −56.3, δ −48.8, and δ −53.0; and 1J C-H couplings of 127 Hz, 126 Hz, and 126 Hz respectively. Of these three species, 13 is the least stable and 5 is the most stable. DFT and ab initio calculations provide further insight into the structures of the [η5-CpM(CO)2(CH4)]+ (M = Os (5), Ru (13) and Fe (17)) complexes and find that the binding free energies of 5, 13 and 17 are -13.6 kcal mol- 1, -10.5 kcal mol-1 and -11.7 kcal mol-1 respectively. Chapter 3 describes results from the low temperature NMR spectroscopic and computational investigations into the ethane σ-complex [η5-CpOs(CO)2(C2H6)][Al(OC(CF3)3)4] (19). The proton resonances, at δ −2.39 (for the osmium-bound CH3) and δ 1.32 (for and the non-bound CH3) were correlated to 13C resonances at δ −30.7 and δ 11.1 respectively. DFT calculations support the observation that there is no exchange observed between the bound and non-bound methyl groups at temperatures as high as -75 ℃, with calculations predicting the barrier to exchange to be a relatively high value of 13.7 kcal mol-1. NMR data show that 19 is more stable than the methane analogue 5, discussed in Chapter 2, consistent with the free energy of binding being calculated to be higher in the case of the ethane complex (-16.6 kcal mol-1). Chapter 4 describes results from the low temperature NMR spectroscopic investigations into the cyclopentane σ-complexes [η5-CpM(CO)2(c-C5H10)][Al(OC(CF3)3)4] (M = Os (20), Ru (22), Fe (23)). The cyclopentane σ-complexes show the same trend in stability as was reported for the methane complexes (20 > 23 > 22). The osmium centred cyclopentane σ-complex (20) is the most stable of the cyclopentane σ-complexes studied here and is sufficiently stable to be observed in solution for a short period (t1/2 = 7.8 mins) at temperatures as high as -50 ℃, making it one of the most stable alkane σ-complexes to be studied in the solution state. Chapter 5 describes preliminary results from the low temperature NMR spectroscopic investigation into the n -pentane σ- complexes [η5-CpM(CO)2(n -C5H12)][Al(OC(CF3)3)4] (M = Os (24) and Ru (25)). NMR data show that the osmium complex preferentially binds methyl groups during UV irradiation, but in the dark the methyl-bound species isomerises to preferentially bind the methylene groups. The ruthenium complex (25) shows a preference to bind via methylene groups under all conditions examined. Chapter 6 draws some overarching conclusions from the investigations presented in this thesis and gives some suggestions to direct future studies in this field. Chapter 7 describes the design and production of an improved experimental apparatus for conducting in situ photolysis of NMR samples with added gaseous reagents and describes the experimental procedures and synthesis of precursor compounds

Proceedings of the 2018 Joint Workshop of Fraunhofer IOSB and Institute for Anthropomatics, Vision and Fusion Laboratory

The Proceeding of the annual joint workshop of the Fraunhofer IOSB and the Vision and Fusion Laboratory (IES) 2018 of the KIT contain technical reports of the PhD-stundents on the status of their research. The discussed topics ranging from computer vision and optical metrology to network security and machine learning. This volume provides a comprehensive and up-to-date overview of the research program of the IES Laboratory and the Fraunhofer IOSB