543 research outputs found
Validazione di un dispositivo indossabile basato sulla realta aumentata per il riposizionamento del mascellare superiore
Aim: We present a newly designed, localiser-free, head-mounted system featuring augmented reality (AR) as an aid to maxillofacial bone surgery, and assess the potential utility of the device by conducting a feasibility study and validation. Also, we implement a novel and ergonomic strategy designed to present AR information to the operating surgeon (hPnP).
Methods: The head-mounted wearable system was developed as a stand- alone, video-based, see-through device in which the visual features were adapted to facilitate maxillofacial bone surgery. The system is designed to exhibit virtual planning overlaying the details of a real patient. We implemented a method allowing performance of waferless, AR-assisted maxillary repositioning. In vitro testing was conducted on a physical replica of a human skull. Surgical accuracy was measured. The outcomes were compared with those expected to be achievable in a three-dimensional environment. Data were derived using three levels of surgical planning, of increasing complexity, and for nine different operators with varying levels of surgical skill.
Results: The mean linear error was 1.70±0.51mm. The axial errors were 0.89±0.54mm on the sagittal axis, 0.60±0.20mm on the frontal axis, and 1.06±0.40mm on the craniocaudal axis. Mean angular errors were also computed. Pitch: 3.13°±1.89°; Roll: 1.99°±0.95°; Yaw: 3.25°±2.26°. No significant difference in terms of error was noticed among operators, despite variations in surgical experience. Feedback from surgeons was acceptable; all tests were completed within 15 min and the tool was considered to be both comfortable and usable in practice.
Conclusion: Our device appears to be accurate when used to assist in waferless maxillary repositioning. Our results suggest that the method can potentially be extended for use with many surgical procedures on the facial skeleton. Further, it would be appropriate to proceed to in vivo testing to assess surgical accuracy under real clinical conditions.Obiettivo: Presentare un nuovo sistema indossabile, privo di sistema di tracciamento esterno, che utilizzi la realtà aumentata come ausilio alla chirurgia ossea maxillo-facciale. Abbiamo validato il dispositivo. Inoltre, abbiamo implementato un nuovo metodo per presentare le informazioni aumentate al chirurgo (hPnP).
Metodi: Le caratteristiche di visualizzazione del sistema, basato sul paradigma video see-through, sono state sviluppate specificamente per la chirurgia ossea maxillo-facciale. Il dispositivo è progettato per mostrare la pianificazione virtuale della chirurgia sovrapponendola all’anatomia del paziente. Abbiamo implementato un metodo che consente una tecnica senza splint, basata sulla realtà aumentata, per il riposizionamento del mascellare superiore. Il test in vitro è stato condotto su una replica di un cranio umano. La precisione chirurgica è stata misurata confrontando i risultati reali con quelli attesi. Il test è stato condotto utilizzando tre pianificazioni chirurgiche di crescente complessità, per nove operatori con diversi livelli di abilità chirurgica.
Risultati: L'errore lineare medio è stato di 1,70±0,51mm. Gli errori assiali erano: 0,89±0,54mm sull'asse sagittale, 0,60±0,20mm sull'asse frontale, e 1,06±0,40mm sull'asse craniocaudale. Anche gli errori angolari medi sono stati calcolati. Beccheggio: 3.13°±1,89°; Rollio: 1,99°±0,95°; Imbardata: 3.25°±2,26°. Nessuna differenza significativa in termini di errore è stata rilevata tra gli operatori. Il feedback dei chirurghi è stato soddisfacente; tutti i test sono stati completati entro 15 minuti e lo strumento è stato considerato comodo e utilizzabile nella pratica.
Conclusione: Il nostro dispositivo sembra essersi dimostrato preciso se utilizzato per eseguire il riposizionamento del mascellare superiore senza splint. I nostri risultati suggeriscono che il metodo può potenzialmente essere esteso ad altre procedure chirurgiche sullo scheletro facciale. Inoltre, appare utile procedere ai test in vivo per valutare la precisione chirurgica in condizioni cliniche reali
Brainstem circuits involved in skilled forelimb movements
Movement is the main output of the nervous system as well as the fundamental form of interaction animals have with their environment. Due to its function and scope, movement has to be characterized by both stability and flexibility. Such apparently conflicting attributes are reflected in the complex organization of the motor system, composed of a vast network of widely distributed circuits interacting with each other to generate an appropriate motor output. Different neuronal structures, located throughout the brain, are responsible for producing a broad spectrum of actions, ranging from simple locomotion to complex goal directed movements such as reaching for food or playing a musical instrument.
The brainstem is one of such structures, holding considerable importance in the generation of the motor output, but also largely unexplored, due to its less-than-accessible anatomic location, functional intricacies and the lack of appropriate techniques to investigate its complexity. Despite recent advances, a deeper understanding of the role of brainstem neuronal circuits in skilled movements is still missing.
In this dissertation, we investigated the involvement of the lateral rostral medulla (LatRM) in the construction of skilled forelimb behaviors. The focus of my work was centered on elucidating the anatomical and functional relationships between LatRM and the caudal brainstem, and specifically on the interactions with the medullary reticular formation, considering both its ventral (MdV) and dorsal subdivisions (MdD).
In summary, we reveal the existence of anatomically segregated subpopulations of neurons in the lower brainstem which encode different aspects of skilled forelimb movements. Moreover, we show that LatRM neurons are necessary for the correct execution of skilled motor programs and their activation produces complex coordinated actions. All this evidence suggests that LatRM may be a key orchestrator for skilled movements by functioning as integration center for upstream signals as well as coordinator by selecting the appropriate effectors in the lower medulla and the spinal cord
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Holoscopic 3D imaging and display technology: Camera/ processing/ display
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonHoloscopic 3D imaging “Integral imaging” was first proposed by Lippmann in 1908. It has become an attractive technique for creating full colour 3D scene that exists in space. It promotes a single camera aperture for recording spatial information of a real scene and it uses a regularly spaced microlens arrays to simulate the principle of Fly’s eye technique, which creates physical duplicates of light field “true 3D-imaging technique”.
While stereoscopic and multiview 3D imaging systems which simulate human eye technique are widely available in the commercial market, holoscopic 3D imaging technology is still in the research phase. The aim of this research is to investigate spatial resolution of holoscopic 3D imaging and display technology, which includes holoscopic 3D camera, processing and display.
Smart microlens array architecture is proposed that doubles spatial resolution of holoscopic 3D camera horizontally by trading horizontal and vertical resolutions. In particular, it overcomes unbalanced pixel aspect ratio of unidirectional holoscopic 3D images. In addition, omnidirectional holoscopic 3D computer graphics rendering techniques are proposed that simplify the rendering complexity and facilitate holoscopic 3D content generation.
Holoscopic 3D image stitching algorithm is proposed that widens overall viewing angle of holoscopic 3D camera aperture and pre-processing of holoscopic 3D image filters are proposed for spatial data alignment and 3D image data processing. In addition, Dynamic hyperlinker tool is developed that offers interactive holoscopic 3D video content search-ability and browse-ability.
Novel pixel mapping techniques are proposed that improves spatial resolution and visual definition in space. For instance, 4D-DSPM enhances 3D pixels per inch from 44 3D-PPIs to 176 3D-PPIs horizontally and achieves spatial resolution of 1365 × 384 3D-Pixels whereas the traditional spatial resolution is 341 × 1536 3D-Pixels. In addition distributed pixel mapping is proposed that improves quality of holoscopic 3D scene in space by creating RGB-colour channel elemental images
A critical practice-based exploration of interactive panoramas' role in helping to preserve cultural memory
I am enclosing the content of two DVDs which are integral part of the practice-based thesis.The rapid development of digital communication technologies in the 20th and 21st centuries has affected the way researchers look at ways memory – especially cultural memory – can be preserved and enhanced. State-of-the-art communication technologies such as the Internet or immersive environments support participation and interaction and transform memory into ‘prosthetic’ experience, where digital technologies could enable 'implantation' of events that have not actually been experienced.
While there is a wealth of research on the preservation of public memory and cultural heritage sites using digital media, more can be explored on how these media can contribute to the cultivation of cultural memory. One of the most interesting phenomena related to this issue is how panoramas, which are immersive and have a well-established tradition in preserving memories, can be enhanced by recent digital technologies and image spaces.
The emergence of digital panoramic video cameras and panoramic environments has opened up new opportunities for exploring the role of interactive panoramas not only as a documentary tool for visiting sites but mainly as a more complex technique for telling non-linear interactive narratives through the application of panoramic photography and panoramic videography which, when presented in a wrap-around environment, could enhance recalling.
This thesis attempts to explore a way of preserving inspirational environments and memory sites in a way that combines panoramic interactive film and traversing the panoramic environment with viewing the photo-realistic panoramic content rather than computer-generated environment.
This research is based on two case studies. The case study of Charles Church in Plymouth represents the topical approach to narrative and focuses on the preservation of the memory of the Blitz in Plymouth and the ruin of Charles Church which stands as a silent reminder of this event. The case study of Charles Causley reflects topographical approach where, through traversing the town of Launceston, viewers learn about Causley’s life and places that provided inspirations for his poems.
The thesis explores through practice what can be done and reflects on positive and less positive aspects of preserving cultural memory in these case studies in a critical way. Therefore, the results and recommendations from this thesis can be seen as valuable contribution to the study of intermedia and cultural memory in general
Advanced Image Acquisition, Processing Techniques and Applications
"Advanced Image Acquisition, Processing Techniques and Applications" is the first book of a series that provides image processing principles and practical software implementation on a broad range of applications. The book integrates material from leading researchers on Applied Digital Image Acquisition and Processing. An important feature of the book is its emphasis on software tools and scientific computing in order to enhance results and arrive at problem solution
The invisible wall between private and public: an artistic exploration of liminality.
Masters Degree.University of KwaZulu-Natal, Pietermaritzburg.This study is a practice-led research project incorporating practical and theoretical
components that investigate the invisible layers that exist between private and public spheres
in physical and digital spaces. The creative practice of the researcher, Kyungeun Seo/Debbie
Seo is located in Oriental and Western painting traditions and expresses conceptual themes of
liminality, private and public, membranes and ‘here and there’.
Practice-led research (PLR) provides both methodological and theoretical support that guides
the direction of this project. The creative practice uncovered key themes, developing a
theoretical framework that integrates theories of liminality, identity, social relationships and
digital media, and locates the study. The practical studio-based component of silk painting plays a central role in uncovering these relationships and bolsters the theoretical interrogation.
The researcher’s experience of sharing the creative practice through social media is
additionally interrogated. The study of 'invisible layers' and liminal space between private and
public, and the relationship between identity and social behaviour are considered in the fine
art context of this degree. The practice of Sanja Iveković provides a framework for
understanding the elision of private and public spheres through contemporary media. David
Spriggs’ installations are referenced as works that make practical use of transparent materials
and layering tactics. Buhlebezwe Siwani provides a South African context for understanding
identity and social behaviour, while Do-ho Suh offers another perspective of living in a liminal space between South Korea and a new, foreign home.
This research project emphasises the integral relationship between theory and practice. The
creative practice is discussed using a reflective and reflexive approach that records and
demonstrates the importance of the unfolding process of the practice, and the connections
between practice, concept and personal experience. Photographs are included alongside the
reflective writings to illustrate the process and findings made through practice. Technical and
practical issues that emerged during the final exhibition installation, and documentation and
submission of the practical component during the COVID-19 lockdown are additionally
examined.Other name Debbie Seo
Graphics Technology in Space Applications (GTSA 1989)
This document represents the proceedings of the Graphics Technology in Space Applications, which was held at NASA Lyndon B. Johnson Space Center on April 12 to 14, 1989 in Houston, Texas. The papers included in these proceedings were published in general as received from the authors with minimum modifications and editing. Information contained in the individual papers is not to be construed as being officially endorsed by NASA
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