Untersuchungen der Blicksteuerung bei Patienten mit peripheren und zentralen okulomotorischen und vestibulären Störungen

Ein Ziel der dieser Habilitationsschrift zugrunde liegenden Versuche war es, durch ein tieferes Verständnis der Mechanismen, die der Blicksteuerung zugrunde liegen, die klinische Diagnostik peripherer und zentraler okulomotorischer und vestibulärer Störungen zu verbessern. Der Fokus lag auf den folgenden fünf unterschiedlichen Projekten mit verschiede-nen methodischen Zugängen, die von Untersuchungen bei Patienten mit strukturellen Läsionen im Mittelhirn bis hin zu methodischen Analysen zur Messung der Funk-tion des VOR reichten und damit ein weites Spektrum erfassten: 1) Systematische Untersuchung dreidimensionaler, kombinierter Augen- und Kopf-bewegungen (Blickbewegungen) bei Normalpersonen und bei Patienten mit Mittel-hirnläsionen 2) Analyse des VOR und Korrelation mit bildmorphologischen Veränderungen bei Patienten mit bilateralen vestibulären Defiziten und zusätzlichen zerebellären Störungen 3) Untersuchung der räumlichen Orientierung in Korrelation mit Veränderungen der Anatomie des limbischen Systems und der weißen Substanz bei Patienten mit bilateraler Vestibulopathie 4) Visuelle Fixation bei Patienten mit zerebellären Störungen, insbesondere mit Downbeat-Nystagmus 5) Ein direkter methodischer Vergleich von zwei Video-Kopfimpuls- (vHIT) Syste-men zur Quantifizierung des angulären VOR Dazu wurde ein breites Spektrum an Messmethoden eingesetzt: Zum Beispiel wur-den Kopf- und Augenbewegungen von Probanden und Patienten mittels der Search Coil-Methode (Robinson 1963) und der Videookulografie analysiert (Übersicht in (Bedell und Stevenson 2013; Eggert 2007)). Zusätzlich wurde sehr eng mit Ingeni-euren, Physikern und Mathematikern zusammengearbeitet, um Methodik und Ana-lyse der experimentellen Ergebnisse zu optimieren. Veränderungen in der kraniellen Bildgebung wurden mittels Verfahren wie der voxelbasierten Morphometrie in der Magnetresonanztomographie erfasst. Verhaltensaufgabenbezogene Veränderungen wurden unter anderem mit dem virtuellen Morris-Wasserlabyrinth analysiert. So konnten anatomische und verhaltensbezogene Veränderungen mit der Blicksteue-rung korreliert werden. Die in dieser Habilitationsschrift zusammengefassten Arbeiten befassen sich mit verschiedenen Aspekten der Blicksteuerung bei Gesunden und Patienten mit unter-schiedlichen peripheren vestibulären und zentralen Erkrankungen; dabei wurde ein breites Spektrum unterschiedlicher Messmethoden eingesetzt – von der Search-Coil Methode über die voxelbasierte Morphometrie im MRT bis hin zum virtuellen Morris-Wasserlabyrinth -, um projektbezogen die einzelnen Fragestellungen spezifisch zu untersuchen. Die wesentlichen Ergebnisse lassen sich wie folgt zusammenfassen: 1) A. Bei freien Blickbewegungen setzt der Kopf eine sog. Torque-basierte Strate-gie (optimale Kontrolle) ein, wogegen das Auge einen Mittelweg zwischen opti-maler und potenzieller Strategie zur Minimierung der angewendeten Kraft ver-wendet. B. Mittelhirnläsionen führen zur kontralateralen Verkippung des Kopfs bei und nach einer Blickbewegung. C. Isolierte, einseitige riMLF-Läsionen bei Menschen führen bei vertikalen Sak-kaden zu einer kontralateralen torsionellen Abweichung des Auges. 2) Zerebelläre Ataxien können auch ohne peripheres vestibuläres Funktionsdefizit klinisch mit einem (falsch-)pathologischen Kopfimpulstest einhergehen. Dies ist am ehesten auf eine Flokkulusdysfunktion zurückzuführen. In diesem Fall ist die niedrigfrequente VOR-Testung mittels kalorischer Testung zuverlässiger zur Detektion einer konkomitanten peripheren vestibulären Störung als die hochfrequente VOR-Testung mittels des Kopfimpulstests. 3) Die bilaterale Vestibulopathie verursacht Defizite in der räumlichen Orientierung und strukturelle Veränderungen im limbischen System und in der weißen Substanz. 4) Die schnellen Phasen des Downbeat-Nystagmus sind nicht immer rein kompensatorisch und verändern sich unter visueller Fixation, unabhängig von der lang-samen Phase. 5) A. Die beiden am häufigsten eingesetzten kommerziellen Video-HIT-Systeme liefern identische Ergebnisse. B. Bei der Auswertung und Beurteilung des Video-HIT muss beachtet werden, dass der VOR-Gain in die Richtung des registrierten Auges um 5 % höher ist als in die entgegengesetzte Richtung. Diese Arbeiten tragen zum besseren Verständnis der Physiologie und Pathophysio-logie sowie zur korrekten topografisch-anatomischen Diagnose innerhalb der komplexen peripheren und zentralen okulomotorischen Systeme bei

Space Exploration Robotic Systems - Orbital Manipulation Mechanisms

In the future, orbital space robots will assist humans in space by constructing and maintaining space modules and structures. Robotic manipulators will play essential roles in orbital operations. This work is devoted to the implemented designs of two different orbital manipulation mechanical grippers developed in collaboration with Thales Alenia Space Italy and NASA Jet Propulsion Laboratory – California Institute of Technology. The consensus to a study phase for an IXV (Intermediate eXperimental Vehicle) successor, a preoperational vehicle called SPACE RIDER (Space Rider Reusable Integrated Demonstrator for European Return), has been recently enlarged, as approved during last EU Ministerial Council. One of the main project task consists in developing SPACE RIDER to conduct on orbit servicing activity with no docking. SPACE RIDER would be provided with a robotic manipulator system (arm and gripper) able to transfer cargos, such as scientific payloads, from low Earth orbiting platforms to SPACE RIDER cargo bay. The platform is a part of a space tug designed to move small satellites and other payloads from Low Earth Orbit (LEO) to Geosynchronous Equatorial Orbit (GEO) and viceversa. The assumed housing cargo bay requirements in terms of volume (<100l) and mass (<50kg) combined with the required overall arm dimensions (4m length), and mass of the cargo (5-30kg) force to developing an innovative robotic manipulator with the task-oriented end effector. It results in a seven degree-of-freedom arm to ensure a high degree of dexterity and a dedicate end-effector designed to grasp the cargo interface. The gripper concept developed consists in a multi-finger hand able to lock both translational and rotational cargo degrees of freedom through an innovative underactuation strategy to limit its mass and volume. A configuration study on the cargo handle interface was performed together with some computer aided design models and multibody analysis of the whole system to prove its feasibility. Finally, the concept of system control architecture, the test report and the gripper structural analysis were defined. In order to be able to accurately analyze a sample of Martian soil and to determine if life was present on the red planet, a lot of mission concepts have been formulating to reach Mars and to bring back a terrain sample. NASA JPL has been studying such mission concepts for many years. This concept is made up of three intermediate mission accomplishments. Mars 2020 is the first mission envisioned to collect the terrain sample and to seal it in sample tubes. These sealed sample tubes could be inserted in a spherical envelope named Orbiting Sample (OS). A Mars Ascent Vehicle (MAV) is the notional rocket designed to bring this sample off Mars, and a Rendezvous Orbiting Capture System (ROCS) is the mission conceived to bring this sample back to Earth through the Earth Entry Vehicle (EEV). MOSTT is the technical work study to create new concepts able to capture and reorient an OS. This maneuver is particularly important because we do not know an OS incoming orientation and we need to be able to capture, to reorient it (2 rotational degrees of freedom), and to retain an OS (3 translational degrees of freedom and 2 rotational ones). Planetary protection requirements generate a need to enclose an OS in two shells and to seal it through a process called Break-The-Chain (BTC). Considering the EEV would return back to Earth, the tubes orientation and position have to be known in detail to prevent any possible damage during the Earth hard landing (acceleration of ∼1300g). Tests and analysis report that in order for the hermetic seals of the sample tubes to survive the impact, they should be located above an OS equator. Due to other system uncertainties an OS presents the potential requirement to be properly reoriented before being inserted inside the EEV. Planetary protection issues and landing safety are critical mission points and provide potential strict requirements to MOSTT system configuration. This task deals with the concept, design, and testbed realization of an innovative electro-mechanical system to reorient an OS consistent with all the necessary potential requirements. One of these electro-mechanical systems consists of a controlled-motorized wiper that explores all an OS surface until it engages with a pin on an OS surface and brings it to the final home location reorienting an OS. This mechanism is expected to be robust to the incoming OS orientation and to reorient it to the desired position using only one degree of freedom rotational actuator

Large Deformation Diffeomorphic Metric Mapping Provides New Insights into the Link Between Human Ear Morphology and the Head-Related Transfer Functions

The research findings presented in this thesis is composed of four sections. In the first section of this thesis, it is shown how LDDMM can be applied to deforming head and ear shapes in the context of morphoacoustic study. Further, tools are developed to measure differences in 3D shapes using the framework of currents and also to compare and measure the differences between the acoustic responses obtained from BEM simulations for two ear shapes. Finally this section introduces the multi-scale approach for mapping ear shapes using LDDMM. The second section of the thesis estimates a template ear, head and torso shape from the shapes available in the SYMARE database. This part of the thesis explains a new procedure for developing the template ear shape. The template ear and head shapes were are verified by comparing the features in the template shapes to corresponding features in the CIPIC and SYMARE database population. The third section of the thesis examines the quality of the deformations from the template ear shape to target ears in SYMARE from both an acoustic and morphological standpoint. As a result of this investigation, it was identified that ear shapes can be studied more accurately by the use of two physical scales and that scales at which the ear shapes were studied were dependent on the parameters chosen when mapping ears in the LDDMM framework. Finally, this section concludes by noting how shape distances vary with the acoustic distances using the developed tools. In the final part of this thesis, the variations in the morphology of ears are examined using the Kernel Principle Component Analysis (KPCA) and the changes in the corresponding acoustics are studied using the standard principle component analysis (PCA). These examinations involved identifying the number of kernel principle components that are required in order to model ear shapes with an acceptable level of accuracy, both morphologically and acoustically

Similarity, Retrieval, and Classification of Motion Capture Data

Three-dimensional motion capture data is a digital representation of the complex spatio-temporal structure of human motion. Mocap data is widely used for the synthesis of realistic computer-generated characters in data-driven computer animation and also plays an important role in motion analysis tasks such as activity recognition. Both for efficiency and cost reasons, methods for the reuse of large collections of motion clips are gaining in importance in the field of computer animation. Here, an active field of research is the application of morphing and blending techniques for the creation of new, realistic motions from prerecorded motion clips. This requires the identification and extraction of logically related motions scattered within some data set. Such content-based retrieval of motion capture data, which is a central topic of this thesis, constitutes a difficult problem due to possible spatio-temporal deformations between logically related motions. Recent approaches to motion retrieval apply techniques such as dynamic time warping, which, however, are not applicable to large data sets due to their quadratic space and time complexity. In our approach, we introduce various kinds of relational features describing boolean geometric relations between specified body points and show how these features induce a temporal segmentation of motion capture data streams. By incorporating spatio-temporal invariance into the relational features and induced segments, we are able to adopt indexing methods allowing for flexible and efficient content-based retrieval in large motion capture databases. As a further application of relational motion features, a new method for fully automatic motion classification and retrieval is presented. We introduce the concept of motion templates (MTs), by which the spatio-temporal characteristics of an entire motion class can be learned from training data, yielding an explicit, compact matrix representation. The resulting class MT has a direct, semantic interpretation, and it can be manually edited, mixed, combined with other MTs, extended, and restricted. Furthermore, a class MT exhibits the characteristic as well as the variational aspects of the underlying motion class at a semantically high level. Classification is then performed by comparing a set of precomputed class MTs with unknown motion data and labeling matching portions with the respective motion class label. Here, the crucial point is that the variational (hence uncharacteristic) motion aspects encoded in the class MT are automatically masked out in the comparison, which can be thought of as locally adaptive feature selection

Humanoid Robot Soccer Locomotion and Kick Dynamics: Open Loop Walking, Kicking and Morphing into Special Motions on the Nao Robot

Striker speed and accuracy in the RoboCup (SPL) international robot soccer league is becoming increasingly important as the level of play rises. Competition around the ball is now decided in a matter of seconds. Therefore, eliminating any wasted actions or motions is crucial when attempting to kick the ball. It is common to see a discontinuity between walking and kicking where a robot will return to an initial pose in preparation for the kick action. In this thesis we explore the removal of this behaviour by developing a transition gait that morphs the walk directly into the kick back swing pose. The solution presented here is targeted towards the use of the Aldebaran walk for the Nao robot. The solution we develop involves the design of a central pattern generator to allow for controlled steps with realtime accuracy, and a phase locked loop method to synchronise with the Aldebaran walk so that precise step length control can be activated when required. An open loop trajectory mapping approach is taken to the walk that is stabilized statically through the use of a phase varying joint holding torque technique. We also examine the basic princples of open loop walking, focussing on the commonly overlooked frontal plane motion. The act of kicking itself is explored both analytically and empirically, and solutions are provided that are versatile and powerful. Included as an appendix, the broader matter of striker behaviour (process of goal scoring) is reviewed and we present a velocity control algorithm that is very accurate and efficient in terms of speed of execution

Exploiting the Potential of Surface Active Ionic Liquids: Fluorinated Ionic Liquids meet Biomolecules

Proteins are macromolecules constituting all the living organisms, being classified as versatile biopolymers, with the widest biological activities. Thus, they have a high impact in different fields, such as the biochemical, biotechnological, chemical, pharmaceutical, and food industries. However, their industrial applications depend on costly downstream processes to yield proteins with high purity, stability, and activity. Moreover, the biological activity of proteins depends on the preservation of the three-dimensional structure, which is determined by the delicate balance between their interactions with compounds in the surrounding environment. To surpass these challenges, ionic liquids (ILs) have emerged in the biological field as an improved asset due to the possibility to design task-specificity materials by selecting the anions and cations composing their structure, and fine-tuning their properties. The surface-active ionic liquids (SAILs) are a highly recognized family of ILs with improved surfactant behaviour. SAILs can be used in the stabilization, extraction, separation, crystallization, and development of protein delivery systems. However, there is still a great lack of knowledge about the interactions between SAILs and proteins, essential information to guide the selection of the best compounds for these bottom-line applications. In this doctoral thesis, fluorinated ionic liquids (FILs), an enhanced family of SAILs, were used to study the interactions between IL-proteins with the aim to develop FIL-based systems for the separation, extraction, and proteins delivery systems. To begin, a review of the literature was performed to understand FILs properties. These compounds grant augmented solubilization mechanisms due to the rich self-aggregation behaviour and can be designed to be completely miscible in aqueous solutions with negligible toxicity, which aids their performance in the biological field. Furthermore, the soft-Statistical Associating Fluid Theory Equation of State (soft-SAFT EoS) was used to model FILs in an intuitive, robust, and reliable way. A straightforward methodology was implemented using soft-SAFT EoS to compute the thermophysical properties of FILs and their mixtures with various solutes. In addition, it was investigated the influence of the structural features of FILs in their self-aggregation behaviour in aqueous solutions. In the end, the impact of the FILs on the solubility, stability, and interaction with different proteins was evaluated. The results of this thesis comprise a proof of concept of the feasibility of FILs-based systems for biological, biochemical, and pharmaceutical applications.As proteínas são macromoléculas que constituem os organismos vivos, sendo classificadas como biopolímeros versáteis, com as mais diversas atividades biológicas. Por isso têm um elevado impacto nas indústrias bioquímica, biotecnológica, química, farmacêutica e alimentícia. No entanto, as suas aplicações industriais dependem de processos de purificação muito dispendiosos para produzir proteínas com alta pureza, estabilidade e atividade. Adicionalmente, a atividade biológica depende da preservação da estrutura tridimensional, que é determinada pelo equilíbrio delicado entre as interações com os compostos no ambiente circundante. Para transpor estes problemas, os líquidos iónicos (LIs) surgiram no campo biológico como um recurso aprimorado porque permite projetar materiais para aplicações específicas, através da seleção dos aniões e catiões que constituem a estrutura dos LIs, customizando as suas propriedades. Os líquidos iónicos tensioativos (LITs) são uma família de LIs com comportamento surfactante. LITs podem ser usados na estabilização, extração, separação, cristalização e desenvolvimento de sistemas de entrega de proteínas. No entanto, ainda existe uma grande falta de conhecimento sobre as interações entre os LITs e as proteínas, o que é essencial para se poder selecionar os melhores LITs para as aplicações biológicas. Nesta tese de doutoramento, uma família de LITs, os líquidos iónicos fluorados (LIFs), foram usados para estudar as interações entre LIs e proteínas com o objetivo de desenvolver sistemas para a separação, extração e sistemas de entrega de proteínas. Para isso, foi realizada uma revisão da literatura para compreender as propriedades dos LIFs. Estes compostos têm mecanismos de solubilização superiores devido ao comportamento de auto-agregação, podendo ser completamente miscíveis em soluções aquosas com reduzida toxicidade, o que permite o seu uso em aplicações biológicas. Além disso, uma equação de estado sustentada na teoria estatística do fluído associante (soft-SAFT EoS) foi usada para modelação dos LIFs de uma forma intuitiva, robusta e confiável. Uma metodologia simplificada foi implementada usando a soft-SAFT EoS para calcular as propriedades termofísicas dos LIFs e das suas misturas com vários solutos. Posteriormente, a influência das características estruturais dos LIFs no seu comportamento de auto-agregação em soluções aquosas foi investigada. Por fim, foi avaliado o impacto dos LIFs na solubilidade, estabilidade e interação com diferentes proteínas. Os resultados desta tese constituem uma prova de conceito da exequibilidade de sistemas baseados em LIFs para aplicações biológicas, bioquímicas e farmacêuticas

Enabling the Development and Implementation of Digital Twins : Proceedings of the 20th International Conference on Construction Applications of Virtual Reality

Welcome to the 20th International Conference on Construction Applications of Virtual Reality (CONVR 2020). This year we are meeting on-line due to the current Coronavirus pandemic. The overarching theme for CONVR2020 is "Enabling the development and implementation of Digital Twins". CONVR is one of the world-leading conferences in the areas of virtual reality, augmented reality and building information modelling. Each year, more than 100 participants from all around the globe meet to discuss and exchange the latest developments and applications of virtual technologies in the architectural, engineering, construction and operation industry (AECO). The conference is also known for having a unique blend of participants from both academia and industry. This year, with all the difficulties of replicating a real face to face meetings, we are carefully planning the conference to ensure that all participants have a perfect experience. We have a group of leading keynote speakers from industry and academia who are covering up to date hot topics and are enthusiastic and keen to share their knowledge with you. CONVR participants are very loyal to the conference and have attended most of the editions over the last eighteen editions. This year we are welcoming numerous first timers and we aim to help them make the most of the conference by introducing them to other participants

59th Annual Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 59th annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Snowbird, Utah, July 22-27, 2018