Haptically assisted connection procedure for the reconstruction of dendritic spines

Dendritic spines are thin protrusions that cover the dendritic surface of numerous neurons in the brain and whose function seems to play a key role in neural circuits. The correct segmentation of those structures is difficult due to their small size and the resulting spines can appear incomplete. This paper presents a four-step procedure for the complete reconstruction of dendritic spines. The haptically driven procedure is intended to work as an image processing stage before the automatic segmentation step giving the final representation of the dendritic spines. The procedure is designed to allow both the navigation and the volume image editing to be carried out using a haptic device. A use case employing our procedure together with a commercial software package for the segmentation stage is illustrated. Finally, the haptic editing is evaluated in two experiments; the first experiment concerns the benefits of the force feedback and the second checks the suitability of the use of a haptic device as input. In both cases, the results shows that the procedure improves the editing accuracy.

Desarrollo de tecnologías de telemanipulación con alto grado de escalado orientadas a la interacción hombre-robot en entornos nucleares

Esta tesis se centra en desarrollo de tecnologías para la interacción hombre-robot en entornos nucleares de fusión. La problemática principal del sector de fusión nuclear radica en las condiciones ambientales tan extremas que hay en el interior del reactor, y la necesidad de que los equipos cumplan requisitos muy restrictivos para poder aguantar esos niveles de radiación, magnetismo, ultravacío, temperatura... Como no es viable la ejecución de tareas directamente por parte de humanos, habrá que utilizar dispositivos de manipulación remota para llevar a cabo los procesos de operación y mantenimiento. En las instalaciones de ITER es obligatorio tener un entorno controlado de extrema seguridad, que necesita de estándares validados. La definición y uso de protocolos es indispensable para regir su buen funcionamiento. Si nos centramos en la telemanipulación con algo grado de escalado, surge la necesidad de definir protocolos para sistemas abiertos que permitan la interacción entre equipos y dispositivos de diversa índole. En este contexto se plantea la definición del Protocolo de Teleoperación que permita la interconexión entre dispositivos maestros y esclavos de distinta tipología, pudiéndose comunicar bilateralmente entre sí y utilizar distintos algoritmos de control según la tarea a desempeñar. Este protocolo y su interconectividad se han puesto a prueba en la Plataforma Abierta de Teleoperación (P.A.T.) que se ha desarrollado e integrado en la ETSII UPM como una herramienta que permita probar, validar y realizar experimentos de telerrobótica. Actualmente, este Protocolo de Teleoperación se ha propuesto a través de AENOR al grupo ISO de Telerobotics como una solución válida al problema existente y se encuentra bajo revisión. Con el diseño de dicho protocolo se ha conseguido enlazar maestro y esclavo, sin embargo con los niveles de radiación tan altos que hay en ITER la electrónica del controlador no puede entrar dentro del tokamak. Por ello se propone que a través de una mínima electrónica convenientemente protegida se puedan multiplexar las señales de control que van a través del cableado umbilical desde el controlador hasta la base del robot. En este ejercicio teórico se demuestra la utilidad y viabilidad de utilizar este tipo de solución para reducir el volumen y peso del cableado umbilical en cifras aproximadas de un 90%, para ello hay que desarrollar una electrónica específica y con certificación RadHard para soportar los enormes niveles de radiación de ITER. Para este manipulador de tipo genérico y con ayuda de la Plataforma Abierta de Teleoperación, se ha desarrollado un algoritmo que mediante un sensor de fuerza/par y una IMU colocados en la muñeca del robot, y convenientemente protegidos ante la radiación, permiten calcular las fuerzas e inercias que produce la carga, esto es necesario para poder transmitirle al operador unas fuerzas escaladas, y que pueda sentir la carga que manipula, y no otras fuerzas que puedan influir en el esclavo remoto, como ocurre con otras técnicas de estimación de fuerzas. Como el blindaje de los sensores no debe ser grande ni pesado, habrá que destinar este tipo de tecnología a las tareas de mantenimiento de las paradas programadas de ITER, que es cuando los niveles de radiación están en sus valores mínimos. Por otro lado para que el operador sienta lo más fielmente posible la fuerza de carga se ha desarrollado una electrónica que mediante el control en corriente de los motores permita realizar un control en fuerza a partir de la caracterización de los motores del maestro. Además para aumentar la percepción del operador se han realizado unos experimentos que demuestran que al aplicar estímulos multimodales (visuales, auditivos y hápticos) aumenta su inmersión y el rendimiento en la consecución de la tarea puesto que influyen directamente en su capacidad de respuesta. Finalmente, y en referencia a la realimentación visual del operador, en ITER se trabaja con cámaras situadas en localizaciones estratégicas, si bien el humano cuando manipula objetos hace uso de su visión binocular cambiando constantemente el punto de vista adecuándose a las necesidades visuales de cada momento durante el desarrollo de la tarea. Por ello, se ha realizado una reconstrucción tridimensional del espacio de la tarea a partir de una cámara-sensor RGB-D, lo cual nos permite obtener un punto de vista binocular virtual móvil a partir de una cámara situada en un punto fijo que se puede proyectar en un dispositivo de visualización 3D para que el operador pueda variar el punto de vista estereoscópico según sus preferencias. La correcta integración de estas tecnologías para la interacción hombre-robot en la P.A.T. ha permitido validar mediante pruebas y experimentos para verificar su utilidad en la aplicación práctica de la telemanipulación con alto grado de escalado en entornos nucleares de fusión. Abstract This thesis focuses on developing technologies for human-robot interaction in nuclear fusion environments. The main problem of nuclear fusion sector resides in such extreme environmental conditions existing in the hot-cell, leading to very restrictive requirements for equipment in order to deal with these high levels of radiation, magnetism, ultravacuum, temperature... Since it is not feasible to carry out tasks directly by humans, we must use remote handling devices for accomplishing operation and maintenance processes. In ITER facilities it is mandatory to have a controlled environment of extreme safety and security with validated standards. The definition and use of protocols is essential to govern its operation. Focusing on Remote Handling with some degree of escalation, protocols must be defined for open systems to allow interaction among different kind of equipment and several multifunctional devices. In this context, a Teleoperation Protocol definition enables interconnection between master and slave devices from different typologies, being able to communicate bilaterally one each other and using different control algorithms depending on the task to perform. This protocol and its interconnectivity have been tested in the Teleoperation Open Platform (T.O.P.) that has been developed and integrated in the ETSII UPM as a tool to test, validate and conduct experiments in Telerobotics. Currently, this protocol has been proposed for Teleoperation through AENOR to the ISO Telerobotics group as a valid solution to the existing problem, and it is under review. Master and slave connection has been achieved with this protocol design, however with such high radiation levels in ITER, the controller electronics cannot enter inside the tokamak. Therefore it is proposed a multiplexed electronic board, that through suitable and RadHard protection processes, to transmit control signals through an umbilical cable from the controller to the robot base. In this theoretical exercise the utility and feasibility of using this type of solution reduce the volume and weight of the umbilical wiring approximate 90% less, although it is necessary to develop specific electronic hardware and validate in RadHard qualifications in order to handle huge levels of ITER radiation. Using generic manipulators does not allow to implement regular sensors for force feedback in ITER conditions. In this line of research, an algorithm to calculate the forces and inertia produced by the load has been developed using a force/torque sensor and IMU, both conveniently protected against radiation and placed on the robot wrist. Scaled forces should be transmitted to the operator, feeling load forces but not other undesirable forces in slave system as those resulting from other force estimation techniques. Since shielding of the sensors should not be large and heavy, it will be necessary to allocate this type of technology for programmed maintenance periods of ITER, when radiation levels are at their lowest levels. Moreover, the operator perception needs to feel load forces as accurate as possible, so some current control electronics were developed to perform a force control of master joint motors going through a correct motor characterization. In addition to increase the perception of the operator, some experiments were conducted to demonstrate applying multimodal stimuli (visual, auditory and haptic) increases immersion and performance in achieving the task since it is directly correlated with response time. Finally, referring to the visual feedback to the operator in ITER, it is usual to work with 2D cameras in strategic locations, while humans use binocular vision in direct object manipulation, constantly changing the point of view adapting it to the visual needs for performing manipulation during task procedures. In this line a three-dimensional reconstruction of non-structured scenarios has been developed using RGB-D sensor instead of cameras in the remote environment. Thus a mobile virtual binocular point of view could be generated from a camera at a fixed point, projecting stereoscopic images in 3D display device according to operator preferences. The successful integration of these technologies for human-robot interaction in the T.O.P., and validating them through tests and experiments, verify its usefulness in practical application of high scaling remote handling at nuclear fusion environments.

Lo intermedio como lugar : lo intersticial, lo fronterizo y lo impreciso en la arquitectura contemporánea

1. Nuestra investigación se centra en el estudio de los “ámbitos o espacios intermedios” en momentos de la arquitectura contemporánea, en un período de transición entre finales de los años 80 y nuestros días. Pretendemos analizar cómo se presenta el ámbito intermedio en el objeto o lugar arquitectónico y su función o relación con el entorno cercano, desde el proyecto hasta su repercusión en la experiencia vivida. 2. El concepto de intermedio entendido como ámbito o espacio intersticial, fronterizo y ambivalente (o multivalente), atraviesa en la presente investigación el campo de la etimología, de la ciencia, del pensamiento y del arte, para detenerse en la arquitectura actual, llevándose a cabo una indagación concreta en el proceso de concepción, en la propuesta formal, espacial y funcional, así como en la percepción y demás experiencias o vivencias en el lugar arquitectónico. 3. En primer lugar nos proponemos estudiar y explorar el concepto de “intermedio” en sus características, funciones y ubicaciones dentro de la cultura contemporánea, detectando sus antecedentes culturales más importantes, para a continuación aplicarlo reflexivamente a obras significativas de arquitectura. La investigación se enfoca en la modalidad figural (imprecisa) de lo intermedio (en alusión al “figural” deleuziano), cuyas metáforas base son lo translúcido, la penumbra y la espuma, vinculadas al actual paradigma cultural de la complejidad (C. Jencks). A continuación se analizan las relaciones o implicaciones de dicha modalidad figural en obras de arquitectos como Eisenman, Holl, Tschumi, Ito, Fujimoto, Van Berkel y Bos, y Siza, comprobando su valor operativo y poniendo de manifiesto su sentido e importancia en la actualidad y en la disciplina. El estudio tiene como trasfondo el concepto de in-between de la obra de Eisenman, y utiliza conceptos de la filosofía del límite de Trías como algunos de sus principales fundamentos. 4. En cada una de las obras de arquitectura presentadas esta modalidad imprecisa se traduce en un ámbito o espacio intermedio figural específico. Son obras en las que real y virtual, matricial y objetual, arquitectura y territorio, existente y nuevo, colectivo e individual, social e íntimo, interior y exterior, y demás usos y funciones se entrelazan o funden. Son arquitecturas cuya geometría ya no se encuentra tan determinada por aspectos bi o tridimensionales del dibujo o de la construcción. A través de la manipulación de estas geometrías más o menos complejas, dinámicas e intersticiales, estas obras reflejan (o intuyen) las premisas del actual Zeitgeist: un cambio de esquemas de objetos a relaciones basado en un pensamiento más holístico, transdisciplinar, sistémico o complejo (E. Morin), y una nueva conciencia colectiva sobre la realidad que anuncia la crisis de la percepción, el cambio de paradigma y nuevos valores (F. Capra). Emerge otra forma de sentir y percibir el mundo, los lugares y los espacios, que poco a poco está cambiando el modo de pensar y dibujar la arquitectura, y consecuentemente de interaccionar con ella. 5. El sentido del espacio intermedio figural, emerge en las cada vez más complejas cualidades morfológico-espaciales y funcionales de una parte importante de la arquitectura actual. Arquitectura, geometría y tecnología informática están más entrelazadas que nunca, y de un modo más libre, para así poder indagar en nuevas formas de pensar y crear lugares en que los “espacios intermedios” que investigamos son un testimonio. El espacio arquitectónico se vuelve afectivo e interactivo, un lugar intermedio figural, formalizado por espacialidades intersticiales que parecen aludir a lo líquido, donde la forma es más matriz que configuración, el espacio más espacialidad que compartimiento, la función más versátil y multivalente que específica o autónoma, y la perplejidad, la imaginación y la evocación se entrecruzan y vuelven patentes. 6. La arquitectura de los lugares intermedios valora no solamente el “plano”, la “configuración” y la “transparencia”, sino sobre todo el “espacio” y la “relación” en sus interrelaciones con los usuarios y demás contextos. De la identidad a la relacionalidad, de la representación a la presentación, es una arquitectura que propone “otros espacios” que más que espacios son topografías y espacialidades intersticiales, de tensión, transición, transformación, relación, intercambio e interacción. Son lugares intermedios reales y virtuales, que se sirven tanto de la morfología como de la topología para conquistar nuevas espacialidades, pretendiendo salir de la estricta operación de “forming”/”morphing”/formación/”conformación” para explorar la de “spacing”/espaciamiento. Son lugares que se basan en conceptos como la zona de indiscernibilidad de Deleuze, la imagen- flujo de Buci-Glucksmann, la suspensión-entre de Sloterdijk, o el espacio no-objetivo al que se refiere José Gil, plasmándose en la arquitectura contemporánea como tropos de lo intersticial. 7. Son los lugares intermedios de la arquitectura actual, de espacialidad háptica, más “afectiva”, generativa e interactiva, donde ese ámbito intermedio transforma y es transformado, “afecta”, “con-mueve” (nos hace mover/accionar) y evoca otros lugares, otras posibilidades de espacio habitable u ocupable. Emerge lo intermedio como lugar, algo que anuncia y exhibe, de manera paradigmática y manifiesta, el monumento de Eisenman en Berlín. ABSTRACT 1. Our research focuses on the study of “in-between spaces or environments” at particular times in contemporary architecture, in a transition period from the end of the 1980’s through to today. We aim to analyse how in-between environments are presented in the architectural object or place and their function or their relationship with the nearby surroundings, from the project through to the experience had. 2. In this research, the in-between concept, understood as an interstitial, border and ambivalent (or multi-purpose) environment or space, is assessed from the viewpoint of etymology, science, thought and art, to conclude in current architecture, with specific exploration of the conception process, of the formal, spatial and functional proposal, together with the perception and other experiences in the architectural place. 3. Firstly, we aim to study and explore the “in-between” concept as regards its features, functions and locations within contemporary culture, revealing its most important cultural background, to then apply it reflexively to important works of architecture. The research focuses on the figural (imprecise) mode of in-between (in allusion to Deleuze’s “figural” approach) whose base metaphors are the translucent, semi-darkness and foam, linked to the current cultural paradigm of complexity (C. Jenks). We then go on to assess the relationships or implications of said figural mode in architectural works by Eisenman, Holl, Tschumi, Ito, Fujimoto, Van Berkel and Bos, and Siza, verifying their operational worth and revealing their meaning and importance today and in this discipline. The backdrop of the study is the in-between concept of Eisenman’s work and it also uses concepts from the philosophy of the limit of Trías as its main underpinnings. 4. In each of the architectural works presented, this imprecise mode is translated into a specific in-between environment or space. They are works in which real and virtual, matricial and objectual, architecture and territory, existing and new, collective and individual, social and intimate, interior and exterior and other uses and functions all intertwine or blend together. They are architectures the geometry of which is not so much determined by bi- or tri-dimensional aspects of the drawing or construction. Through the manipulation of these more or less complex, dynamic and interstitial geometries, these works reflect (or insinuate) the premises of the current Zeitgeist: A change in the scheme of objects to relationships towards a more holistic, transdisciplinary, systemic or complex thought (E. Morin), and a new collective conscience about the reality which announces the crisis of perception, the change in paradigm and new values (F. Capra). Another way of feeling and perceiving the world, places and spaces, which little by little is changing the way of thinking and drawing architecture and hence of interacting with it. 5. The meaning of figural in-between space emerges in the increasingly complex, morphological-spatial and functional qualities of a large part of architecture today. Architecture, geometry and computer technology are more than ever intertwined in a freer way to inquire into other ways of thinking and making places, where the “in-between” spaces we research are a testimony. Architectural space becomes affective and interactive, a figural in-between place, formed by interstitial spatiality which seems to allude to something liquid, where shape is more matrix than configuration, space more spatiality than compartment, its function more versatile and multi-purpose than specific or autonomous, and perplexity, imagination and evocation criss-cross each other, becoming obvious. 6. The architecture of in-between places values not only “flat”, “configuration” and “transparency”, but above all “space” and the “relationship” in its interrelations with users and other contexts. From identity to relationality, from representation to presentation, it is an architecture that proposes “other spaces”, which more than spaces are topographies and interstitial spatialities, of tension, transition, transformation, relation, exchange and interaction. They are real and virtual in-between places, that take in both morphology and topology to conquer new spatialities, aiming to depart from the strict “forming”/”morphing” operation in order to explore “spacing”. They are places that derive both from Deleuze’s indiscernibility zone concept, from Buci-Glucksmann´s image-flow concept, from Sloterdijk’s suspension-between, and from the non-objective space referred to by José Gil, and they are embodied in contemporary architecture as tropes of the interstitial. 7. They are the in-between places in architecture today, of haptic spatiality, more “affective”, generative and interactive, where that in-between environment transforms and is transformed, “affects”, “moves” (it makes us move/act) and evokes other places, other possibilities of habitable or occupiable space. The in-between emerges as a place, which paradigmatically and declaredly, Eisenman´s monument in Berlin announces and exhibits. RESUMO 1. A investigação centra-se no estudo dos “âmbitos ou espaços intermédios” em momentos da arquitectura contemporânea, no período de transição entre os finais dos anos 80 e os nossos dias. Pretende-se analisar como se apresenta o âmbito intermédio no objecto ou lugar arquitectónico e sua função ou relação com o meio envolvente, desde o projecto até à sua repercussão na experiencia vivenciada. 2. O conceito de intermédio entendido como âmbito ou espaço intersticial, fronteiriço e ambivalente (ou multivalente), atravessa na presente investigação o campo da etimologia, da ciência, do pensamento e da arte, para deter-se na arquitectura actual, realizando-se uma indagação concreta no processo de concepção, na proposta formal, espacial e funcional, assim como na percepção e demais experiencias ou vivencias no lugar arquitectónico. 3. Em primeiro lugar, explora-se o conceito de “intermédio” nas suas características, funções e concretizações na cultura contemporânea, detectando os seus antecedentes culturais mais importantes, para em seguida aplicá-lo reflexivamente a obras significativas de arquitectura. A investigação centra-se na modalidade figural (imprecisa) do intermédio (alusão ao figural deleuziano) cujas metáforas base são o translúcido, a penumbra e a espuma, relacionadas com o actual paradigma da complexidade (C. Jencks). Em seguida analisam-se as relações ou implicações da referida modalidade figural em obras de arquitectos como Eisenman, Holl, Tschumi, Ito, Fujimoto, Van Berkel e Bos, e Siza, como modo de comprovar o seu valor operativo e revelar o seu sentido e importância na actualidade e na disciplina. O estudo tem como referencia o conceito de in-between da obra de Eisenman, e utiliza conceitos da filosofia do limite de Trias como alguns dos seus principais fundamentos. 4. Em cada uma das obras de arquitectura apresentadas esta modalidade imprecisa traduz-se num âmbito ou espaço intermédia figural especifico. São obras nas quais real e virtual, matricial e objectual, arquitectura e território, existente e novo, colectivo e individual, social e intimo, interior e exterior, e outros usos e funções se entrelaçam ou fundem. São arquitecturas cuja geometria já não está tão determinada por aspectos bi ou tridimensionais do desenho ou da construção. Através do uso destas geometrias mais ou menos complexas, dinâmicas e intersticiais, estas obras reflectem (ou intuem) as premissas do actual zeitgeist: uma mudança de esquemas de objectos a relações para um pensamento mais holístico, transdisciplinar, sistémico ou complexo (E. Morin) e uma nova consciência colectiva sobre a realidade, que anuncia a crise da percepção, a mudança de paradigma e novos valores (F. Capra). Emerge uma outra forma de sentir e perceber o mundo, os lugares e os espaços, que gradualmente vai alterando o modo de pensar e desenhar a arquitectura, e consequentemente de interagir com ela. 5. O sentido do espaço intermédio figural, emerge nas cada vez mais complexas qualidades morfológico-espaciais e funcionais de uma parte importante da arquitectura actual. Cada vez mais, arquitectura, geometria e tecnologia informática, relacionam-se de um modo mais livre para indagar outras formas de pensar e fazer lugares, onde os espaços intermédios que investigamos são um testemunho. O espaço arquitectónico torna-se afectivo e interactivo, um lugar intermédio figural, formalizado por espacialidades intersticiais que parecem aludir ao estado liquido, onde a forma é mais matriz que configuração, o espaço mais espacialidade que compartimento, a função mais versátil e multivalente que especifica ou autónoma, e a perplexidade, a imaginação e a evocação entrecruzam-se e tornam-se patentes. 6. A arquitectura dos lugares intermédios valoriza não só o “plano”, a “configuração” e a “transparência”, mas sobretudo o” espaço” e a ”relação” nas suas inter-relações com os utentes e restante contextos. Da identidade à relacionalidade, da representação à apresentação, é uma arquitectura que propõe “outros espaços”, que além de espaços são topografias e espacialidades intersticiais, de tensão, transição, transformação, relação, intercambio e interacção. São lugares intermédios reais e virtuais que utilizam tanto a morfologia como a topologia para conquistar novas espacialidades, pretendendo ultrapassar a estrita operação de “forming”/“morphing”/formação para explorar a de “spacing”/espaçamento. São lugares que se apoiam tanto no conceito de zona de indescernibilidade de Deleuze, como na de imagem-fluxo de Buci-Glucksmann como no de suspensão–entre de Sloterdijk ou de espaço-não objectivo que refere José Gil, e se plasmam na arquitectura contemporânea como tropos do intersticial. 7. São os lugares intermédios da arquitectura actual, de espacialidade háptica, mais “afectiva”, generativa e interactiva, onde esse âmbito intermédio transforma e é transformado, “afecta”, ”co-move “(nos faz mover/agir) e evoca outros lugares, outras possibilidades de espaço habitável ou ocupável. Emerge o intermédio como lugar que, paradigmática e manifestamente, o monumento de Eisenmann em Berlim, anuncia e exibe.

Active materiality : the agency of matter from the phenomenological perspective = Materialidad activa : la operatividad de la materia desde el punto de vista fenomenológico

The role of matter has remained central to the making and the thinking of architecture, yet many attempts to capture its essence have been trapped in a dialectic tension between form and materiality, between material consistency and immaterial modes of perception, between static states and dynamic processes, between the real and the virtual, thus advancing an increasing awareness of the perplexing complexity of the material world. Within that complexity, the notion of agency – emerging from and within ecological, politico-economic and socio-cultural processes – calls for a reconceptualization of matter, and consequently processes of materialisation, offering a new understanding of context and space, approached as a field of dynamic relationships. In this context, cutting across boundaries between architectural discourse and practice as well as across the vast trans-disciplinary territory, this dissertation aims to illustrate a variety of design methodologies that have derived from the relational approach. More specifically, the intention is to offer new insights into spatial epistemologies embedded within the notion of atmosphere – commonly associated with the so-called New Phenomenology – and to reflect upon its implications for architectural production. In what follows, the intended argumentation has a twofold dimension. First, through a scrutiny of the notion of atmosphere, the aim is to explore ways of thinking and shaping reality through relations, thus acknowledging the aforementioned complexity of the material universe disclosed through human and non-human as well as material and immaterial forces. Secondly, despite the fact that concerns for atmospherics have flourished over the last few decades, the objective is to reveal that the conceptual foundations and procedures for the production of atmosphere might be found beneath the surface of contemporary debates. Hence, in order to unfold and illustrate previously advocated assumptions, an archaeological approach is adopted, tracing a particular projective genealogy, one that builds upon an atmospheric awareness. Accordingly, in tracing such an atmospheric awareness the study explores the notoriously ambiguous nature and the twofold dimension of atmosphere – meteorological and aesthetic – and the heterogeneity of meanings embedded in them. In this context, the notion of atmosphere is presented as parallactic. It transgresses the formal and material boundaries of bodies. It calls for a reevaluation of perceptual experience, opening a new gap that exposes the orthodox space-bodyenvironment relationships to questioning. It offers to architecture an expanded domain in which to manifest itself, defining architectural space as a contingent construction and field of engagement, and presenting matter as a locus of production/performance/action. Consequently, it is such an expanded or relational dimension that constitutes the foundation of what in the context of this study is to be referred to as affective tectonics. Namely, a tectonics that represents processual and experiential multiplicity of convergent time and space, body and environment, the material and the immaterial; a tectonics in which matter neither appears as an inert and passive substance, nor is limited to the traditionally regarded tectonic significance or expressive values, but is presented as an active element charged with inherent potential and vitality. By defining such a relational materialism, the intention is to expand the spectrum of material attributes revealing the intrinsic relationships between the physical properties of materials and their performative, transformative and affective capacities, including effects of interference and haptic dynamics – i.e. protocols of transmission and interaction. The expression that encapsulates its essence is: ACTIVE MATERIALITY RESUMEN El significado de la materia ha estado desde siempre ligado al pensamiento y el quehacer arquitectónico. Sin embargo, muchos intentos de capturar su esencia se han visto sumergidos en una tensión dialéctica entre la forma y la materialidad, entre la consistencia material y los modos inmateriales de la percepción, entre los estados estáticos y los procesos dinámicos, entre lo real y lo virtual, revelando una creciente conciencia de la desconcertante complejidad del mundo material. En esta complejidad, la noción de la operatividad o capacidad agencial– que emerge desde y dentro de los procesos ecológicos, políticos y socio-culturales– requiere de una reconceptualización de la materia y los procesos inherentes a la materialización, ofreciendo una nueva visión del contexto y el espacio, entendidos como un campo relacional dinámico. Oscilando entre el discurso arquitectónico y la práctica arquitectónica, y atravesando un extenso territorio trans-disciplinar, el objetivo de la presente tesis es ilustrar la variedad de metodologías proyectuales que emergieron desde este enfoque relacional. Concretamente, la intención es indagar en las epistemologías espaciales vinculadas a la noción de la atmósfera– generalmente asociada a la llamada Nueva Fenomenología–, reflexionando sobre su impacto en la producción arquitectónica. A continuación, el estudio ofrece una doble línea argumental. Primero, a través del análisis crítico de la noción de atmósfera, el objetivo es explorar maneras de pensar y dar forma a la realidad a través de las relaciones, reconociendo la mencionada complejidad del universo material revelado a través de fuerzas humanas y no-humanas, materiales e inmateriales. Segundo, a pesar de que el interés por las atmósferas ha florecido en las últimas décadas, la intención es demostrar que las bases conceptuales y los protocolos proyectuales de la creación de atmósferas se pueden encontrar bajo la superficie de los debates contemporáneos. Para corroborar e ilustrar estas hipótesis se propone una metodología de carácter arqueológico, trazando una particular genealogía de proyectos– la que se basa en una conciencia atmosférica. Asimismo, al definir esta conciencia atmosférica, el estudio explora tanto la naturaleza notoriamente ambigua y la dimensión dual de la atmósfera– meteorológica y estética–, como la heterogeneidad de significados derivados de ellas. En este contexto, la atmósfera se entiende como un concepto detonante, ya que sobrepasa los limites formales y materiales de los cuerpos, llevando a la re-evaluación de la experiencia perceptiva y abriendo a preguntas la ortodoxa relación espacio- cuerpo-ambiente. En consecuencia, la noción de la atmósfera ofrece a la arquitectura una dimensión expandida donde manifestarse, definiendo el espacio como una construcción contingente, performativa y afectiva, y presentando la materia como locus de producción/ actuación/ acción. Es precisamente esta dimensión expandida relacional la que constituye una base para lo que en el contexto del presente estudio se define como una tectónica afectiva. Es decir, una tectónica que representa una multiplicidad procesual y experiencial derivada de la convergencia entre el tiempo y el espacio, el cuerpo y el entorno, lo material y lo inmaterial; una tectónica en la que la materia no aparece como una substancia pasiva e inerte, ni es limitada al significado considerado tradicionalmente constructivo o a sus valores expresivos, sino que se presenta como elemento activo cargado de un potencial y vitalidad inherentes. A través de la definición de este tipo de materialismo afectivo, la intención es expandir el espectro de los atributos materiales, revelando las relaciones intrínsecas entre las propiedades físicas de los materiales y sus capacidades performativas, transformativas y afectivas, incluyendo efectos de interferencias y dinámicas hápticas– o dicho de otro modo, protocolos de transmisión e interacción. Una expresión que encapsula su esencia vendría a ser: MATERIALIDAD ACTIVA

Biomechanical factors may explain why grasping violates Weber's law

Copyright © 2015. Published by Elsevier Ltd. Acknowledgments The experiment was part of N. Aschenneller’s MD thesis. The study was funded by the Staedtler Stiftung (Nuremberg, Germany).

Mnemonic neuronal activity in somatosensory cortex.

Single-unit activity was recorded from the hand areas of the somatosensory cortex of monkeys trained to perform a haptic delayed matching to sample task with objects of identical dimensions but different surface features. During the memory retention period of the task (delay), many units showed sustained firing frequency change, either excitation or inhibition. In some cases, firing during that period was significantly higher after one sample object than after another. These observations indicate the participation of somatosensory neurons not only in the perception but in the short-term memory of tactile stimuli. Neurons most directly implicated in tactile memory are (i) those with object-selective delay activity, (ii) those with nondifferential delay activity but without activity related to preparation for movement, and (iii) those with delay activity in the haptic-haptic delayed matching task but no such activity in a control visuo-haptic delayed matching task. The results indicate that cells in early stages of cortical somatosensory processing participate in haptic short-term memory.

Stability of a Novel Intraocular Lens Design: Comparison of Two Trifocal Lenses

PURPOSE: To compare visual outcomes, rotational stability, and centration in a randomized controlled trial in patients undergoing cataract surgery who were bilaterally implanted with two different trifocal intraocular lenses (IOLs) with a similar optical zone but different haptic shape. METHODS: Twenty-one patients (42 eyes) with cataract and less than 1.50 D of corneal astigmatism underwent implantation of one FineVision/MicoF IOL in one eye and one POD FineVision IOL in the contralateral eye (PhysIOL, Liège, Belgium) at IOA Madrid Innova Ocular, Madrid, Spain. IOL allocation was random. Outcome measures, all evaluated 3 months postoperatively, included monocular and binocular uncorrected distance (UDVA), corrected distance (CDVA), distance-corrected intermediate (DCIVA), and near (DCNVA) visual acuity (at 80, 40, and 25 cm) under photopic conditions, refraction, IOL centration, haptic rotation, dysphotopsia, objective quality of vision and aberration quantification, patient satisfaction, and spectacle independence. RESULTS: Three months postoperatively, mean monocular UDVA, CDVA, DCIVA, and DCNVA (40 cm) under photopic conditions were 0.04 ± 0.07, 0.01 ± 0.04, 0.15 ± 0.11, and 0.16 ± 0.08 logMAR for the eyes implanted with the POD FineVision IOL and 0.03 ± 0.05, 0.01 ± 0.02, 0.17 ± 0.12, and 0.14 ± 0.08 logMAR for those receiving the FineVision/MicroF IOL. Moreover, the POD FineVision IOL showed similar centration (P > .05) and better rotational stability (P < .05) than the FineVision/MicroF IOL. Regarding halos, there was a minimal but statistically significant difference, obtaining better results with FineVision/MicroF. Full spectacle independence was reported by all patients. CONCLUSIONS: This study revealed similar visual outcomes for both trifocal IOLs under test (POD FineVision and FineVision/MicroF). However, the POD FineVision IOL showed better rotational stability, as afforded by its design.

Comparative Analysis of the Visual Performance After Cataract Surgery With Implantation of a Bifocal or Trifocal Diffractive IOL

PURPOSE: To evaluate and compare the visual, refractive, contrast sensitivity, and aberrometric outcomes with a diffractive bifocal and trifocal intraocular lens (IOL) of the same material and haptic design. METHODS: Sixty eyes of 30 patients undergoing bilateral cataract surgery were enrolled and randomly assigned to one of two groups: the bifocal group, including 30 eyes implanted with the bifocal diffractive IOL AT LISA 801 (Carl Zeiss Meditec, Jena, Germany), and the trifocal group, including eyes implanted with the trifocal diffractive IOL AT LISA tri 839 MP (Carl Zeiss Meditec). Analysis of visual and refractive outcomes, contrast sensitivity, ocular aberrations (OPD-Scan III; Nidek, Inc., Gagamori, Japan), and defocus curve were performed during a 3-month follow-up period. RESULTS: No statistically significant differences between groups were found in 3-month postoperative uncorrected and corrected distance visual acuity (P > .21). However, uncorrected, corrected, and distance-corrected near and intermediate visual acuities were significantly better in the trifocal group (P < .01). No significant differences between groups were found in postoperative spherical equivalent (P = .22). In the binocular defocus curve, the visual acuity was significantly better for defocus of -0.50 to -1.50 diopters in the trifocal group (P < .04) and -3.50 to -4.00 diopters in the bifocal group (P < .03). No statistically significant differences were found between groups in most of the postoperative corneal, internal, and ocular aberrations (P > .31), and in contrast sensitivity for most frequencies analyzed (P > .15). CONCLUSIONS: Trifocal diffractive IOLs provide significantly better intermediate vision over bifocal IOLs, with equivalent postoperative levels of visual and ocular optical quality.

The role of local luminance amplitude in the interpretation of shape-from-shading in textured surfaces

Luminance changes within a scene are ambiguous; they can indicate reflectance changes, shadows, or shading due to surface undulations. How does vision distinguish between these possibilities? When a surface painted with an albedo texture is shaded, the change in local mean luminance (LM) is accompanied by a similar modulation of the local luminance amplitude (AM) of the texture. This relationship does not necessarily hold for reflectance changes or for shading of a relief texture. Here we concentrate on the role of AM in shape-from-shading. Observers were presented with a noise texture onto which sinusoidal LM and AM signals were superimposed, and were asked to indicate which of two marked locations was closer to them. Shape-from-shading was enhanced when LM and AM co-varied (in-phase), and was disrupted when they were out-of-phase. The perceptual differences between cue types (in-phase vs out-of-phase) were enhanced when the two cues were present at different orientations within a single image. Similar results were found with a haptic matching task. We conclude that vision can use AM to disambiguate luminance changes. LM and AM have a positive relationship for rendered, undulating, albedo textures, and we assess the degree to which this relationship holds in natural images. [Supported by EPSRC grants to AJS and MAG].

A developmental dissociation of view-dependent and view-invariant object recognition in adolescence

Spatial generalization skills in school children aged 8-16 were studied with regard to unfamiliar objects that had been previously learned in a cross-modal priming and learning paradigm. We observed a developmental dissociation with younger children recognizing objects only from previously learnt perspectives whereas older children generalized acquired object knowledge to new viewpoints as well. Haptic and - to a lesser extent - visual priming improved spatial generalization in all but the youngest children. The data supports the idea of dissociable, view-dependent and view-invariant object representations with different developmental trajectories that are subject to modulatory effects of priming. Late-developing areas in the parietal or the prefrontal cortex may account for the retarded onset of view-invariant object recognition. © 2006 Elsevier B.V. All rights reserved.

What is second-order vision for? Discriminating illumination versus material changes

The human visual system is sensitive to second-order modulations of the local contrast (CM) or amplitude (AM) of a carrier signal. Second-order cues are detected independently of first-order luminance signals; however, it is not clear why vision should benet from second-order sensitivity. Analysis of the first-and second-order contents of natural images suggests that these cues tend to occur together, but their phase relationship varies. We have shown that in-phase combinations of LM and AM are perceived as a shaded corrugated surface whereas the anti-phase combination can be seen as corrugated when presented alone or as a flat material change when presented in a plaid containing the in-phase cue. We now extend these findings using new stimulus types and a novel haptic matching task. We also introduce a computational model based on initially separate first-and second-order channels that are combined within orientation and subsequently across orientation to produce a shading signal. Contrast gain control allows the LM + AM cue to suppress responses to the LM-AM when presented in a plaid. Thus, the model sees LM -AM as flat in these circumstances. We conclude that second-order vision plays a key role in disambiguating the origin of luminance changes within an image. © ARVO.

Cellular interaction with novel biomaterials

The objective of this thesis is to report the behaviour of mammalian cells with biocompatible synthetic polymers with potential for applications to the human body. Composite hydrogel materials were tested as possible keratoprosthetic devices. It was found that surface topography is an important consideration, pores, channels and fibres exposed on the surface of the hydrogels tested can have significant effects on the extent of cell adheson and proliferation. It is recommended that the core component is fabricated out of one of the following to provide a non cell adhesive base; A8, A11, A13, A22, A23. The haptic periphery fabricated out of one of the following would provide a cell adhesive composite; A16, A30, A33, A37, A38, A42, A43, A44. The presence of vitronectin in the ocular tissue appears to lead to higher cell adhesion to the posterior surface of a contact lens when compared to the anterior surface. Group IV contact lenses adhere more cells than Group II contact lenses - this may indicate that more protein (including vitronectin) is able to adhere to the contact lens due to the Group IV contact lenses high water content and ionic hydrogel matrix. Artificial lung surfactant analogues were found to be non cytotoxic but also decreased cell proliferation when tested at higher concentrations. Poly(lysine ethyl ester adipamide) [PLETESA] had the most favourable response on cell proliferation and commercial styrene/maleic anhydride (pMA/STY sp2) the most pronounced inhibitory response. The mode of action that decreases cell proliferation appears to be through membrane destabilization. Tissue culture well plates coated with PLETESA allowed cells to adhere in a concentration dependent manner, multilaminar liposomes possibly of PLETESA were observed in solution in PLETESA coated wells. Polyhydroxybutryate (PHB) and polyhydroxyvalerate (PHV) blends that contained hydroxyapatite were found to be the most cell adhesive material of those materials tested. The blends that were most susceptible to degradation adhered the most cells in initial stages of degradation. The initial slight increase in cell adhesion may be due to the increased rugosity of the material. As the degradation continued the number of cells adhering to the samples decreased, this may indicate that the polarity was inhibitory to cell adhesion during the later stages of degradation.

Evaluation of modern intraocular lenses

Accommodating Intraocular Lenses (IOLs), multifocal IOLs (MIOLs) and toric IOLs are designed to provide a greater level of spectacle independency post cataract surgery. All of these IOLs are reliant on the accurate calculation of intraocular lens power determined through reliable ocular biometry. A standardised defocus area metric and reading performance index metric were devised for the evaluation of the range of focus and the reading ability of subjects implanted with presbyopic correcting IOLs. The range of clear vision after implantation of an MIOL is extended by a second focal point; however, this results in the prevalence of dysphotopsia. A bespoke halometer was designed and validated to assess this photopic phenomenon. There is a lack of standardisation in the methods used for determining IOL orientation and thus rotation. A repeatable, objective method was developed to allow the accurate assessment of IOL rotation, which was used to determine the rotational and positional stability of a closed loop haptic IOL. A new commercially available biometry device was validated for use with subjects prior to cataract surgery. The optical low coherence reflectometry instrument proved to be a valid method for assessing ocular biometry and covered a wider range of ocular parameters in comparison with previous instruments. The advantages of MIOLs were shown to include an extended range of clear vision translating into greater reading ability. However, an increased prevalence of dysphotopsia was shown with a bespoke halometer, which was dependent on the MIOL optic design. Implantation of a single optic accommodating IOL did not improve reading ability but achieved high subjective ratings of near vision. The closed-loop haptic IOL displayed excellent rotational stability in the late period but relatively poor rotational stability in the early period post implantation. The orientation error was compounded by the high frequency of positional misalignment leading to an extensive overall misalignment of the IOL. This thesis demonstrates the functionality of new IOL lens designs and the importance of standardised testing methods, thus providing a greater understanding of the consequences of implanting these IOLs. Consequently, the findings of the thesis will influence future designs of IOLs and testing methods.

Imagery in multi-modal object learning

Spatial objects may not only be perceived visually but also by touch. We report recent experiments investigating to what extent prior object knowledge acquired in either the haptic or visual sensory modality transfers to a subsequent visual learning task. Results indicate that even mental object representations learnt in one sensory modality may attain a multi-modal quality. These findings seem incompatible with picture-based reasoning schemas but leave open the possibility of modality-specific reasoning mechanisms.

Mobile assistive technologies for the visually impaired

There are around 285 million visually impaired people worldwide, and around 370,000 people are registered as blind or partially sighted in the UK. Ongoing advances in information technology (IT) are increasing the scope for IT-based mobile assistive technologies to facilitate the independence, safety, and improved quality of life of the visually impaired. Research is being directed at making mobile phones and other handheld devices accessible via our haptic (touch) and audio sensory channels. We review research and innovation within the field of mobile assistive technology for the visually impaired and, in so doing, highlight the need for successful collaboration between clinical expertise, computer science, and domain users to realize fully the potential benefits of such technologies. We initially reflect on research that has been conducted to make mobile phones more accessible to people with vision loss. We then discuss innovative assistive applications designed for the visually impaired that are either delivered via mainstream devices and can be used while in motion (e.g., mobile phones) or are embedded within an environment that may be in motion (e.g., public transport) or within which the user may be in motion (e.g., smart homes). © 2013 Elsevier Inc.