Towards identification of finger flexions using single channel surface electromyography - able bodied and amputee subjects

This research has established a method for using single channel surface electromyogram (sEMG) recorded from the forearm to identify individual finger flexion. The technique uses the volume conduction properties of the tissues and uses the magnitude and density of the singularities in the signal as a measure of strength of the muscle activity. Methods: SEMG was recorded from the flexor digitorum superficialis muscle during four different finger flexions. Based on the volume conduction properties of the tissues, sEMG was decomposed into wavelet maxima and grouped into four groups based on their magnitude. The mean magnitude and the density of each group were the inputs to the twin support vector machines (TSVM). The algorithm was tested on 11 able-bodied and one trans-radial amputated volunteer to determine the accuracy, sensitivity and specificity. The system was also tested to determine inter-experimental variations and variations due to difference in the electrode location. Results: Accuracy and sensitivity of identification of finger actions from single channel sEMG signal was 93% and 94% for able-bodied and 81% and 84% for trans-radial amputated respectively, and there was only a small inter-experimental variation. Conclusions: Volume conduction properties based sEMG analysis provides a suitable basis for identifying finger flexions from single channel sEMG. The reported system requires supervised training and automatic classification

Empirical modelling and classification of surface electromyogram

This thesis develops an effective feature extraction technique for sEMG signals. Surface electromyography (sEMG) is the recording of a muscle’s electrical activity from the surface of the skin. The signal contains information that is related to the anatomy and physiology of the muscle. In clinical applications, the signal is used for the diagnosis of neuro-muscular diseases and disorders. Another application of sEMG is for device control application where the signal is used for controlling devices such as prosthetic devices, robots, and human – machine interfaces. Signal classification is used to extract relevant information that represent a particular state (or class) of the sEMG signal. This stater (or class) of the sEMG depicts the information about the underlying pathology or is used as control input for other devices. Therefore it is important that the sEMG is classified in to the relevant class with high accuracy to ensure reliable application in a given field. Many researchers have attempted to improve the classification accuracy of the sEMG signal. Generally the number of electrodes attached to the surface of the skin also needs to be increased in order to increase the classification accuracy. In some cases this number becomes prohibitively high. On the other hand, with a decrease in the number of electrodes the classification accuracy has been reported to decrease. In order to overcome these challenges, in this thesis a new feature extraction technique has been developed. As opposed to the established global time or frequency domain analysis of the sEMG signal, the technique developed in this thesis relies on the well established volume conduction model of sEMG generation. Developed feature extraction technique is then applied to sEMG recorded from low level digital contraction with low signal to noise ratio. A high classification rate of approximately 93% in four classes of low level contraction was achieved by using single channel of sEMG recording. It was further established that the placement of electrode did not have significant effect on the accuracy and reliability of the classification. Further developments that may improve on the methods established in this thesis are presented in the end

Sensors for Vital Signs Monitoring

Sensor technology for monitoring vital signs is an important topic for various service applications, such as entertainment and personalization platforms and Internet of Things (IoT) systems, as well as traditional medical purposes, such as disease indication judgments and predictions. Vital signs for monitoring include respiration and heart rates, body temperature, blood pressure, oxygen saturation, electrocardiogram, blood glucose concentration, brain waves, etc. Gait and walking length can also be regarded as vital signs because they can indirectly indicate human activity and status. Sensing technologies include contact sensors such as electrocardiogram (ECG), electroencephalogram (EEG), photoplethysmogram (PPG), non-contact sensors such as ballistocardiography (BCG), and invasive/non-invasive sensors for diagnoses of variations in blood characteristics or body fluids. Radar, vision, and infrared sensors can also be useful technologies for detecting vital signs from the movement of humans or organs. Signal processing, extraction, and analysis techniques are important in industrial applications along with hardware implementation techniques. Battery management and wireless power transmission technologies, the design and optimization of low-power circuits, and systems for continuous monitoring and data collection/transmission should also be considered with sensor technologies. In addition, machine-learning-based diagnostic technology can be used for extracting meaningful information from continuous monitoring data

Développement et validation d'un instrument non-invasifde caractérisation du comportement musculaire respiratoire

Réalisé en cotutelle avec l'Université Joseph Fourier École Doctorale Ingénierie pour la Santé,la Cognition et l'Environnement (France)Les progrès en anesthésie et en réanimation ont pour objectifs la réduction de la durée de surveillance et l'amélioration de la qualité de la récupération. Pour le cas particulier de l'assistance respiratoire, la capacité de surveiller et d'optimiser l'adaptation entre le patient et sa machine d'assistance est déterminante pour la qualité et la conduite des soins. Ce travail de thèse concerne dans sa première partie la mise en place et la validation d'un outil instrumental permettant de caractériser un comportement respiratoire par l'étude cycle à cycle du délai d'activation inspiratoire entre les muscles des voies aériennes supérieures et de la cage thoracique. Cet outil doit prendre en compte les contraintes imposées par le milieu clinique telle qu'une mesure non-invasive des muscles respiratoires. Il repose sur une mesure électromyographique (EMG) de surface des muscles respiratoires. La mesure cycle à cycle et par voie de surface du délai d'activation est un véritable challenge dans un environnement clinique qui est fortement perturbé. La démarche choisie ici est double avec en parallèle : i) La mise en place d'un outil de détection d'évènements menée sous supervision. ii) La définition d'un protocole original sur sujets sains prenant en compte les contraintes cliniques et permettant de valider l'outil et de constituer une base de connaissances pour envisager l'automatisation des procédés dans un travail futur. D'un point de vue physiologique, l'influence de la fréquence respiratoire sur le délai d'activation de l'inspiration n'a pas été étudiée à ce jour. Ce délai a donc été mesuré en condition de normocapnie à différentes fréquences respiratoires imposées par un stimulus sonore. Une étude statistique montre que l'instrument permet de distinguer deux situations physiologiques du protocole expérimental, ce qui en dé- montre la sensibilité. La deuxième partie de ce travail de thèse s'inscrit dans le cadre d'une optimisation des méthodes de détection de singularités d'intérêt. La solution choisie ici se base sur l'intensité structurelle qui calcule la "densité" de maxima d'ondelettes à différentes échelles et permet une localisation des singularités d'un signal bruité. Une formulation de cet outil qui utilise la transformée de Berkner est proposée. Celle-ci permet le chaînage des maxima d'ondelette afin de positionner précisément les amers du signal. Le filtrage de l'artefact ECG dans l'EMG diaphragmatique sans signal de référence est proposé comme exemple d'application.Better care in an anaesthesia and critical care could be achieved by reducing monitoring duration and improving the quality of recovery. For the particular case of respiratory assistance, the capacity to track and optimize patient-ventilator synchrony is essential to quality care. As a first step, this thesis adresses the development and validation of an instrument which characterizes respiratory behavior by studying the time lag between onset of upper airway muscles and rib cage muscles, cycle by cycle during respiration. This tool must take into account the constraints imposed by the clinical environment ; measuring respiratory muscles by surface electromyographic measurements (EMG). Measurement of the onset time lag, cycle by cycle and non invasively, is a true challenge in a critical care clinical environment. Here the approach is two-fold : i) The development of a tool for events detection. ii) The definition of an original protocol on healthy subjects. The tool development constitutes a knowledge bases to eventually develop automation of the processes in future work. From a physiological point of view, the influence of respiratory rate on the EMG onset time lag during inspiration has not been studied. Thus we measured this time lag in normocapnia at various respiratory rates imposed by a sound stimulus. Statistically, the instrumental tool can distinguish two physiological situations in this experimental protocol, which confirms its sensitivity. The second step of this thesis is part of an optimization of events detection methods with singularities of interest. The chosen solution is based on structural intensity which computes the "density" of the locations of the modulus maxima of a wavelet representation along various scales in order to identify singularities of an unknown signal. An improvement is proposed by applying Berkner transform which allows maxima linkage to insure accurate localization of landmarks. An application to cancel ECG interference in diaphragmatic EMG without a reference signal is also proposed

Characterising evoked potential signals using wavelet transform singularity detection

This research set out to develop a novel technique to decompose Electroencephalograph (EEG) signal into sets of constituent peaks in order to better describe the underlying nature of these signals. It began with the question; can a localised, single stimulation of sensory nervous tissue in the body be detected in the brain? Flash Visual Evoked Potential (VEP) tests were carried out on 3 participants by presenting a flash and recording the response in the occipital region of the cortex. By focussing on analysis techniques that retain a perspective across different domains - temporal (time), spectral (frequency/scale) and epoch (multiple events) - useful information was detected across multiple domains, which is not possible in single domain transform techniques. A comprehensive set of algorithms to decompose evoked potential data into sets of peaks was developed and test ed using wavelet transform singularity detection methods. The set of extracted peaks then forms the basis for a subsequent clustering analysis which identifies sets of localised peaks that contribute the most towards the standard evoked response. The technique is quite novel as no closely similar work in research has been identified. New and valuable insights into the nature of an evoked potential signal have been identified. Although the number of stimuli required to calculate an Evoked Potential response has not been reduced, the amount of data contributing to this response has been effectively reduced by 75%. Therefore better examination of a small subset of the evoked potential data is possible. Furthermore, the response has been meaningfully decomposed into a small number (circa 20) of constituent peaksets that are defined in terms of the peak shape (time location, peak width and peak height) and number of peaks within the peak set. The question of why some evoked potential components appear mor e strongly than others is probed by this technique. Delineation between individual peak sizes and how often they occur is for the first time possible and this representation helps to provide an understanding of how particular evoked potentials components are made up. A major advantage of this techniques is the there are no pre-conditions, constraints or limitations. These techniques are highly relevant to all evoked potential modalities and other brain signal response applications - such as in brain-computer interface applications. Overall, a novel evoked potential technique has been described and tested. The results provide new insights into the nature of evoked potential peaks with potential application across various evoked potential modalities

Achieving sustainable wastewater treatment through Nexus thinking

This present habilitation thesis in wastewater systems explores the theoretical and practical implications of achieving sustainability through and in wastewater treatment. It herby uses the discussions on circularity, sustainability and nexus thinking while investigating their relationship amongst each other and in their relation to wastewater treatment. This thesis consists of seven main chapters. Chapter 1 provides an overview of the approach in which the present manuscript delves into the aspects of circularity, sustainability and nexus concepts and wastewater treatment. Chapter 2 to 5 contain the manuscripts that relate to (a) conceptual considerations, (b) examples of circularity, (c) sustainability assessments and (d) nexus applications. Chapter 6 provides a series of lessons learned from the collated findings. Chapter 7 holds the appendix with supplemental information from the respective manuscripts. The work is based on a variety of publications that the author and her team members produced primarily between January 2016 and October 2019 (and in part until the submission of this thesis). While they include 5 published first-author peer-reviewed publications some sections also contain further relevant co-authored publications. Water security is key for a sustainable world. Wastewater can play a critical role towards provisioning water sustainably to address water scarcity and water stress. However, wastewater treatment is currently itself not sustainable. For wastewater treatment to be put on a sustainable footing, systemic change of the sector and the way wastewater is viewed needs to occur. Wastewater treatment can provide a series of resources for circular use – with nature-based solutions offering co-benefits over grey infrastructure that extend to other nexus sectors such as food and energy. However, circularity does not necessarily equate with sustainability. Environmental components are just one of the three dimensions of sustainability, but data for indicators for social and economic aspects of wastewater treatment are scarce. Moving towards sustainable solutions may only be possible by employing tools that step away from an ever-better understanding of current systems and shifting towards modes of analysis that help generate target and transformation knowledge in inter- and transdisciplinary research and project settings. These views mandate a radical revision of current curricula of engineers and other disciplines to include courses on social, economic and environmental dimensions of sustainability. Training in designing, conducting and evaluating participatory processes that include a variety of stakeholders may significantly improve future generations’ capacities to design, construct, and operate sustainable wastewater treatment systems that provide treated wastewater as a sustainable source of water in a water secure world.:ABSTRACT vii ZUSAMMENFASSUNG (ABSTRACT in German) ix ACKNOWLEDGMENTS xi 1 Introduction 2 1.1 Scope 2 1.2 The structure of this work 8 1.3 References 10 2 Conceptual explorations 14 2.1 Learning from Integrated Management Approaches to Implement the Nexus 15 2.1.1 Introduction 16 2.1.2 Methods 19 2.1.3 Results 21 2.1.4 Discussion 26 2.1.5 Conclusion 27 2.1.6 References 29 2.2 Making the Water–Soil–Waste Nexus Work: Framing the Boundaries of Resource Flows 33 2.2.1 Introduction 34 2.2.2 An Overview of Integrated Approaches Related to the WSW Nexus 36 2.2.3 The System Boundaries of Integrated Environmental Management Approaches 38 2.2.4 What Is Different This Time?—The Boundary of the Water–Soil–Waste Nexus System 41 2.2.5 Illustrating the Boundaries of the WSW Nexus System—Case Studies 43 2.2.6 Conclusions 48 2.2.7 References and Notes 50 3 Examples of circularity 56 3.1 The Role of Constructed Wetlands for Biomass Production within the Water-Soil-Waste Nexus 59 3.1.1 Introduction 60 3.1.2 Methods 63 3.1.3 Results and discussion 63 3.1.4 Conclusions 68 3.1.5 References 70 3.2 Constructed Wetlands for Resource Recovery in Developing Countries 73 3.2.1 Introduction 74 3.2.2 Methods 76 3.2.3 Results 80 3.2.4 Discussion 91 3.2.5 Conclusions 99 3.2.6 References 102 4 Assessing sustainability of wastewater systems 110 4.1 Assessing Sustainability of Wastewater Management Systems in a Multi-Scalar, Transdisciplinary Manner in Latin America 113 4.1.1 Introduction 114 4.1.2 Materials and Methods 116 4.1.3 Results 124 4.1.4 Discussion 129 4.1.5 Conclusion 132 4.1.6 References 134 4.2 Selecting Sustainable Sewage Sludge Reuse Options through a Systematic Assessment Framework: Methodology and Case Study in Latin America 137 4.2.1 Introduction 138 4.2.2 Methods 139 4.2.3 Results and discussion 141 4.2.4 Conclusion 154 4.2.5 References 156 5 Applying the Nexus 160 5.1 Considering Resources Beyond Water: Irrigation and Drainage Management in the Context of the Water–Energy–Food Nexus 161 5.1.1 Introduction 163 5.1.2 Integrating resource management through Nexus thinking 165 5.1.3 Assessing the negative and positive environmental effects of irrigation, and the provision of ecosystem services 169 5.1.4 The role of stakeholders in governing irrigation 171 5.1.5 Conclusion 173 5.1.6 References 175 5.2 Co-generating knowledge in nexus research for sustainable wastewater management 177 5.2.1 Introduction 178 5.2.2 Material and Methods 180 5.2.3 Results 184 5.2.4 Discussion 202 5.2.5 Conclusions 204 5.2.6 References 206 6 Lessons learned and outlook 210 6.1 Increased circularity does not equate in increased sustainability. 212 6.2 Data scarcity hampers quantitative knowledge generation. 214 6.3 Moving from systems’ understanding to comprehensive knowledge generation for systemic change. 217 6.4 Participation and inclusion of stakeholders is important and should not be an afterthought. 218 6.5 References 221 7 Supplemental Information (SI)/Supplemental Material (SM) 226 7.1 SI for 4.1 ‘Assessing Sustainability of Wastewater Management Systems in a Multi-Scalar, Transdisciplinary Manner in Latin America’ 226 Appendix A 226 Appendix B 233 Appendix C 240 Appendix D 241 Appendix E 243 Appendix F 251 7.2 SI for 4.2 ‘Selecting Sustainable Sewage Sludge Reuse Options through a Systematic Assessment Framework: Methodology and Case Study in Latin America’ 256 7.3 SI for 5.1 ‘Co-generating knowledge in nexus research for sustainable wastewater management’ 261 7.3.1 SM1: Expert interview questionnaire assessing information on stakeholder’s perspectives. 261 7.3.2 SM2: Wickedness Analysis questions 264 7.3.3 SM3: Detailed results of the stakeholder perspective of wastewater treatment in each case 265 7.3.4 SM4: Detailed responses to the workshop/training evaluations 272 8 Contribution of the author in collaborative publications 283 9 Eidesstattliche Versicherung 285Diese Habilitationsschrift untersucht die theoretischen und praktischen Implikationen der Erreichung von Nachhaltigkeit durch und in der Abwasserbehandlung. Sie nutzt die Diskussionen über Kreislaufwirtschaft, Nachhaltigkeit und Nexus-Denken und untersucht deren Beziehung untereinander und in ihrem Verhältnis zur Abwasserbehandlung. Dieses Manuskript besteht aus sieben Hauptkapiteln. Kapitel 1 gibt einen Überblick über den Ansatz, in dem das vorliegende Manuskript die Aspekte der Kreislaufwirtschaft, Nachhaltigkeit und Nexus-Konzepte und Abwasserbehandlung untersucht. Kapitel 2 bis 5 enthält die Manuskripte, die sich auf (a) konzeptionelle Überlegungen, (b) Beispiele für Kreislaufwirtschaft, c) Nachhaltigkeitsbewertungen und (d) Nexusanwendungen beziehen. Kapitel 6 enthält eine Reihe von Einsichten, die aus den gesammelten Erkenntnissen gezogen wurden. Das letzte Kapitel enthält die Zusatzdaten und -informationen einiger der Artikel. Die Arbeit basiert auf einer Vielzahl von Publikationen, die die Autorin und ihre Teammitglieder hauptsächlich zwischen Januar 2016 und Oktober 2019 (und teilweise bis zur Einreichung dieser Arbeit) erstellt haben. Während sie 5 veröffentlichte Erstautoren-Peer-Review-Publikationen umfassen, enthalten manche Abschnitte auch weitere relevante, mitverfasste Veröffentlichungen. Wassersicherheit ist unumgänglich für eine nachhaltige Welt. Abwasser kann eine Schlüsselrolle bei der Bereitstellung einer nachhaltigen Wasserquelle spielen, um Wasserknappheit und Wasserstress zu bewältigen. Die Abwasserbehandlung selbst ist jedoch derzeit nicht nachhaltig. Damit die Abwasserbehandlung auf eine nachhaltige Grundlage gestellt werden kann, müssen die Sektoren und die Art und Weise, wie Abwasser betrachtet wird, verändert werden. Die Abwasserbehandlung kann eine Reihe von Ressourcen für die Kreislaufwirtschaft bereitstellen – naturbasierte Lösungen bieten weitere Vorteile gegenüber grauer Infrastruktur, die sich auf andere Nexus-Sektoren wie Nahrung und Energie erstrecken. Kreislaufwirtschaft ist jedoch nicht unbedingt gleichbedeutend mit Nachhaltigkeit. Umweltkomponenten sind nur eine der drei Dimensionen der Nachhaltigkeit, aber Daten für Indikatoren für soziale und wirtschaftliche Aspekte der Abwasserbehandlung sind rar. Der Übergang zu nachhaltigen Lösungen ist möglicherweise nur möglich, wenn Instrumente eingesetzt werden, die sich von einem immer besseren Verständnis aktueller Systeme entfernen und sich in Richtung Analysemodi bewegen, die dazu beitragen, Ziel- und Transformationswissen in inter- und transdisziplinären Forschungs- und Projektumgebungen zu generieren. Diese Ergebnisse schreiben eine radikale Überarbeitung der aktuellen Lehrpläne von Ingenieuren und anderen Disziplinen vor, um Kurse über soziale, wirtschaftliche und ökologische Dimensionen der Nachhaltigkeit aufzunehmen. Schulungen in der Konzeption, Durchführung und Bewertung partizipatorischer Prozesse, die eine Vielzahl von Akteuren einbeziehen, können die Kapazitäten der zukünftigen Generation zur Planung, Konstruktion und zum Betrieb nachhaltiger Abwasserbehandlungssysteme, die behandeltes Abwasser als nachhaltige Wasserquelle in einer wassersicheren Welt bereitstellen, erheblich verbessern.:ABSTRACT vii ZUSAMMENFASSUNG (ABSTRACT in German) ix ACKNOWLEDGMENTS xi 1 Introduction 2 1.1 Scope 2 1.2 The structure of this work 8 1.3 References 10 2 Conceptual explorations 14 2.1 Learning from Integrated Management Approaches to Implement the Nexus 15 2.1.1 Introduction 16 2.1.2 Methods 19 2.1.3 Results 21 2.1.4 Discussion 26 2.1.5 Conclusion 27 2.1.6 References 29 2.2 Making the Water–Soil–Waste Nexus Work: Framing the Boundaries of Resource Flows 33 2.2.1 Introduction 34 2.2.2 An Overview of Integrated Approaches Related to the WSW Nexus 36 2.2.3 The System Boundaries of Integrated Environmental Management Approaches 38 2.2.4 What Is Different This Time?—The Boundary of the Water–Soil–Waste Nexus System 41 2.2.5 Illustrating the Boundaries of the WSW Nexus System—Case Studies 43 2.2.6 Conclusions 48 2.2.7 References and Notes 50 3 Examples of circularity 56 3.1 The Role of Constructed Wetlands for Biomass Production within the Water-Soil-Waste Nexus 59 3.1.1 Introduction 60 3.1.2 Methods 63 3.1.3 Results and discussion 63 3.1.4 Conclusions 68 3.1.5 References 70 3.2 Constructed Wetlands for Resource Recovery in Developing Countries 73 3.2.1 Introduction 74 3.2.2 Methods 76 3.2.3 Results 80 3.2.4 Discussion 91 3.2.5 Conclusions 99 3.2.6 References 102 4 Assessing sustainability of wastewater systems 110 4.1 Assessing Sustainability of Wastewater Management Systems in a Multi-Scalar, Transdisciplinary Manner in Latin America 113 4.1.1 Introduction 114 4.1.2 Materials and Methods 116 4.1.3 Results 124 4.1.4 Discussion 129 4.1.5 Conclusion 132 4.1.6 References 134 4.2 Selecting Sustainable Sewage Sludge Reuse Options through a Systematic Assessment Framework: Methodology and Case Study in Latin America 137 4.2.1 Introduction 138 4.2.2 Methods 139 4.2.3 Results and discussion 141 4.2.4 Conclusion 154 4.2.5 References 156 5 Applying the Nexus 160 5.1 Considering Resources Beyond Water: Irrigation and Drainage Management in the Context of the Water–Energy–Food Nexus 161 5.1.1 Introduction 163 5.1.2 Integrating resource management through Nexus thinking 165 5.1.3 Assessing the negative and positive environmental effects of irrigation, and the provision of ecosystem services 169 5.1.4 The role of stakeholders in governing irrigation 171 5.1.5 Conclusion 173 5.1.6 References 175 5.2 Co-generating knowledge in nexus research for sustainable wastewater management 177 5.2.1 Introduction 178 5.2.2 Material and Methods 180 5.2.3 Results 184 5.2.4 Discussion 202 5.2.5 Conclusions 204 5.2.6 References 206 6 Lessons learned and outlook 210 6.1 Increased circularity does not equate in increased sustainability. 212 6.2 Data scarcity hampers quantitative knowledge generation. 214 6.3 Moving from systems’ understanding to comprehensive knowledge generation for systemic change. 217 6.4 Participation and inclusion of stakeholders is important and should not be an afterthought. 218 6.5 References 221 7 Supplemental Information (SI)/Supplemental Material (SM) 226 7.1 SI for 4.1 ‘Assessing Sustainability of Wastewater Management Systems in a Multi-Scalar, Transdisciplinary Manner in Latin America’ 226 Appendix A 226 Appendix B 233 Appendix C 240 Appendix D 241 Appendix E 243 Appendix F 251 7.2 SI for 4.2 ‘Selecting Sustainable Sewage Sludge Reuse Options through a Systematic Assessment Framework: Methodology and Case Study in Latin America’ 256 7.3 SI for 5.1 ‘Co-generating knowledge in nexus research for sustainable wastewater management’ 261 7.3.1 SM1: Expert interview questionnaire assessing information on stakeholder’s perspectives. 261 7.3.2 SM2: Wickedness Analysis questions 264 7.3.3 SM3: Detailed results of the stakeholder perspective of wastewater treatment in each case 265 7.3.4 SM4: Detailed responses to the workshop/training evaluations 272 8 Contribution of the author in collaborative publications 283 9 Eidesstattliche Versicherung 28