The company Forsslund Systems has developed a simulator for oral surgery training. The simulator, named Kobra, uses detailed virtual models of surgical situations, spatial haptics and a co-located stereoscopic display to provide an environment in which students can practice surgical techniques. Four years after the introduction of the Kobra a need was recognized for a new hardware design that satisfies the customers expectations on visual appearance and hardware refinement and that aims to improve the experience for the end users. This report describes the design development process of the new enclosure, that had a focus on human-centered design, brand management and small-scale manufacturing. Inspired by findings from a comprehensive user study, conducted at a teaching hospital in Riga and relevant literature, as well as the results of prototyping and testing, the new design of the Kobra aims to improve the usability and market attractiveness of the product offering. This while being tailored to utilize the manufacturing technologies available to a small-scale in-house or out-sourced production team. A full-scale functioning prototype of the concept was built in-house, using the proposed means of manufacture, demonstrating a design that is close to ready for production. / Simulatorn, kallad Kobra, använder detaljerade virtuella modeller av kirurgiska ingrepp, 3D-haptik och en samlokaliserad stereoskopisk skärm för att skapa en miljö där elever kan öva kirurgiska tekniker. Fyra år efter introduktionen av Kobran klargjordes ett behov av en ny hårdvarudesign som uppfyller kundernas förväntningar på utseende och hårdvarukvalité samt som syftar till att förbättra upplevelsen för slutanvändarna. Denna rapport beskriver designutvecklingsprocessen av den nya exteriören, som hade utgångspunkt från människocentrerad design, varumärkeshantering och småskalig tillverkning. Inspirerad av insikter från en omfattande användarstudie, genomförd på ett lärosäte i Riga och relevant litteratur, såväl som resultaten av prototyptillverkning och utvärdering, syftar den nya designen av Kobran till att förbättra användbarhet och produktens marknadsläge. Detta medans designen är skräddarsydd för att utnyttja de tillverkningsprocesser som är tillgängliga för ett småskaligt internt eller externt produktionslag. En fullskalig fungerande prototyp av konceptet byggdes, med hjälp av de föreslagna tillverkningsmetoderna, som påvisade en nära produktionsklar design.

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<p>Have a nice day :)</p> / <p>This thesis presents a unified framework for coordination and control of human-in-the-loop asymmetric semi-autonomous robotic systems. It introduces a highly general teleoperation system configuration involving any number of operators, haptic interfaces, and robots with possibly different degrees of mobility. The proposed framework allows for mixed teleoperation/autonomous control of user-defined subtasks by establishing position/force tracking as well as kinematic constraints among relevant <em>teleoperation control frames</em>. Three layers of velocity-based autonomous subtasks at different priority levels with respect to human teleoperation are integrated into the control system design. The control strategy is hierarchical comprising of a high-level teleoperation coordinating controller and low-level joint velocity controllers. A Lyapunov-based adaptive joint-space velocity controller is presented as one candidate for the low-level control. The approach utilizes idempotent, generalized pseudoinverse and weighting matrices, as well as a soft-switching rank changing algorithm in order to achieve new performance objectives that are defined for such asymmetric semi-autonomous teleoperation systems. A detailed analysis of system performance and stability is presented. The proposed framework constitutes the most general formulation and solution for the teleoperation control problem to date. It yields many interesting and useful system configurations never studied before, in addition to those already considered in the literature. In particular, seven system configurations arising from the proposed teleoperation architecture are analyzed and studied in detail. Experimental results are provided to demonstrate the desired system response in these configurations. Moreover, human factors experiments are carried out to assess operator(s) performance in maneuverability and grasping under various teleoperation system configurations. The results show statistically significant performance improvement in teleoperation of a nonholonomic mobile robot and telegrasping using a twin-armed manipulator.</p> / Doctor of Philosophy (PhD)

Detta examensarbete utfördes för att ta reda på hur viktig skuggning är som djupinformationsbärare i en multimodal simulator för operativ extraktion av visdomständer. Simulatorn har både haptik och stereografik som kan förmedla djupinformation. Frågeställningen för examensarbetet var därför att undersöka om det fanns något behov av att använda sig av en relativt beräkningstung rendering med skuggning, eller om det skulle duga med en enklare typ av rendering. Användartester har utförts med erfarna tandläkare som har fått prova på simulatorn med olika typer av renderingar av ett och samma patientfall. Metoden som användes kallas kooperativ utvärdering vilken tillåter diskussion mellan användaren och utvärderaren. Det visar sig att skuggningen spelar en mycket stor roll för användarens djupuppfattning. Skuggningen visar sig faktiskt vara betydligt viktigare än stereoinformationen, särskilt som tandläkarna fokuserar på ett mycket litet område där stereoeffekten verkar försumbar. Det är även viktigt att väga in det faktum att inte alla kan se djup i stereobilder. Då de tänkta användarna är relativt unga tandläkarstudenter är de vana vid nästan verklighetstrogen grafik från dataspel och datoranimerad film. Därför bör grafiken i simulatorn ligga så nära den standarden som möjligt. Användandet av haptik gör visserligen att användaren kan känna var denna befinner sig i djupled, men vid konflikt med synintrycken så verkar synen ta överhanden. Slutsatsen blir därmed att skuggning definitivt är värd att implementeras, trots de extra resurser som krävs. / The aim of this thesis was to investigate the importance shading has on the perception of depth in a multimodal simulator for operative extraction of wisdom teeth. The simulator uses both haptics and stereo graphics to convey information about depth. The problem formulated in the thesis was to investigate the necessity of using shading, which is quite demanding computationally, or if a simpler type of rendering would suffice. User tests have been performed with experienced dentists who have tried different graphical renderings of the same patient case in the simulator. The method used for the tests is called cooperative evaluation and allows for discussions between the user and the evaluator. Shading turns out to play an important role in the users’ perception of depth. It even seems to be more important than the stereo information since the area the dentists focus on is so small the stereo effect seems negligible. The fact that not all people can see depth in stereo images is also important to consider. As the intended users are relatively young dental students, they are accustomed to almost photorealistic graphics in computer games and computer animation. Therefore the graphics in the simulator needs to be as close to that standard as possible. The use of haptics does make it possible for the user to feel where s/he is located depthwise, but when a conflict with the visual feedback occurs, the visual information tends to dominate. The conclusion therefore is to recommend that shading definitely is worth implementing, even though it requires additional resources.

<p>This thesis describes a six-month project based on stroke rehabilitation and involves designing with medical doctors, a physiotherapist and an occupational therapist, prototyping and evaluating with both stroke patients and other users. Our project involves the construction of a rehabilitation exercise system, based on virtual environments (VE) and haptics, designed for stroke patients. Our system uses a commercially available haptic device called the PHANTOM Omni, which has the possibility of being used as a rehabilitation tool to interact with virtual environments. The PHANTOM Omni is used in combination with our own developed software based on the platform H3D API. Our goal is to construct an application which will motivate the stroke patient to start using their arm again.</p><p>We give a review of the different aspects of stroke, rehabilitation, VE and haptics and how these have previously been combined. We describe our findings from our literature studies and from informal interviews with medical personnel. From these conclusions we attempt to take the research area further by suggesting and evaluating designs of different games/genres that can be used with the PHANTOM Omni as possible haptic exercises for post-stroke arm rehabilitation. We then present two different implementations to show how haptic games can be constructed. We mainly focus on an application we built, a game, using an iterative design process based on studies conducted during the project, called "The Labyrinth". The game is used to show many of the different aspects that have to be taken into account when designing haptic games for stroke patients. From a study with three stroke patients we have seen that "The Labyrinth" has the potential of being a stimulating, encouraging and fun exercise complement to the traditional rehabilitation. Through the design process and knowledge we acquired during this thesis we have created a set of general design guidelines that we believe can help in the future software development of haptic games for post-stroke arm rehabilitation.</p>

Historically, haptics—all different aspects of the sense of touch and its study—has developed around very technical and scientific inquiries. Despite considerable haptic research advances and the obviousness of haptics in everyday life, this modality remains mostly foreign and unfamiliar to designers. The guiding motif of this research relates to a desire to reverse the situation and have designers designing for and with the haptic sense, for human use and looking beyond technical advances. Consequently, this thesis aims to nurture the development of haptics from a designerly perspective, leading to a new field of activities labeled haptic interaction design. It advances that haptic attributes and characteristics are increasingly part of the qualities that make up the interactions and the experiences we have with objects and the interfaces that surround us, and that these considerations can and ought to be knowingly and explicitly designed by designers. The book encompasses an annotated research through design exploration of the developing field of haptic interaction design, building on a considerable account of self-initiated individual design activities and empirical-style group activities with others. This extensive investigation of designing haptic interactions leads to the Simple Haptics proposition, an approach to ease the discovery and appropriation of haptics by designers. Simple Haptics consists in a simplistic, rustic approach to the design of haptic interactions, and advocates an effervescence of direct perceptual experiences in lieu of technical reverence. Simple Haptics boils down to three main traits: 1) a reliance on sketching in hardware to engage with haptics; 2) a fondness for basic, uncomplicated, and accessible tools and materials for the design of haptic interactions; and 3) a strong focus on experiential and directly experiencable perceptual qualities of haptics.  Ultimately, this thesis offers contributions related to the design of haptic interactions. The main knowledge contribution relates to the massification of haptics, i.e. the intentional realization and appropriation of haptics—with its dimensions and qualities—as a non-visual interaction design material. Methodologically, this work suggests a mixed longitudinal approach to haptics in a form of a well-grounded interplay between personal inquiries and external perspectives. The book also presents design contributions as ways to practically, physically and tangibly access, realize and explore haptic interactions. Globally these contributions help make haptics concrete, graspable, sensible and approachable for designers. The hope is to inspire design researchers, students and practitioners to discover and value haptics as a core component of any interaction design activities.

In recent years, researchers have developed virtual environments, which allow more realistic human-computer interactions and have become increasingly popular for engineering applications such as computer-aided design and process evaluation. For instance, the demand for product service, remanufacture, and recycling has forced companies to consider ease of assembly and disassembly during the design phase of their products. Evaluating these processes in a virtual environment during the early stages of design not only increases the impact of design modifications on the final product, but also eliminates the time, cost, and material associated with the construction of physical prototypes. Although numerous virtual environments for assembly analysis exist or are under development, many provide only visual feedback. A real-time haptic simulation test bed for the analysis of assembly and disassembly operations has been developed, providing the designer with force and tactile feedback in addition to traditional visual feedback. The development such a simulation requires the modeling of collisions between virtual objects, which is a computationally expensive process. Also, the demands of a real-time simulation incorporating haptic feedback introduce additional complications for reliable collision detection. Therefore, the first objective of this work was to discover ways in which current collision detection libraries can be improved or supplemented to create more robust interaction between virtual objects. Using the simulation as a test bed, studies were then conducted to determine the potential usefulness of haptic feedback for analysis of assembly and disassembly operations. The following significant contributions were accomplished: (1) a simulation combining the strengths of an impulse-based simulation with a supplemental constraint maintenance scheme for modeling object interactions, (2) a toolkit of supplemental techniques to support object interactions in situations where collision detection algorithms commonly fail, (3) a haptic assembly and disassembly simulation useful for experimentation, and (4) results from a series of five experimental user studies with the focus of determining the effectiveness of haptic feedback in such a simulation. Additional contributions include knowledge of the usability and functionality of current collision detection libraries, the limitations of haptic feedback devices, and feedback from experimental subjects regarding their comfort and overall satisfaction with the simulation.

Persons suffering central nervous system damage, such as a stroke, coma patients, or individuals that have suffered damage to the spinal cord, brainstem, cerebellum, and motor cortex, sometimes develop an asymmetric walking pattern where one leg does not fully swing backward. This uneven gait hinders these individuals in properly and efficiently moving through everyday life. Previous research in humans and various animals has introduced a split belt treadmill to analyze possible rehabilitation, which can recreate a correct gait pattern by altering the speed of each track. Gait adaptation was achieved by having the split belt treadmill move each leg at a different velocity relative to the ground and thus forcing a symmetric gait. Test subjects‟ gait would adapt to the speeds and a normal gait pattern could be conditioned while on the split belt treadmill. However, after short trials, individuals were unable to neurologically store these feed-forward walking patterns once walking over ground. Also, test subjects would have difficulty adapting their learned walking gait over different walking environments. The gait enhancing mobile shoe (GEMS) makes it possible to adjust an asymmetric walking gait so that both legs move at a relatively symmetric speed over ground. It alters the wearers walking gait by forcing each foot backwards during the stance phase, operating solely by mechanical motion, transferring the wearer‟s downward force into a horizontal backwards motion. Recreating the split belt treadmill effect over ground by using the GEMS will potentially enable me to test the long term effects of a corrected gait, which is impossible using a split belt treadmill. A previous prototype of the GEMS [1] successfully generated a split belt treadmill walking pattern, but had various drawbacks, such as variable motion from step to step. My new design of this rehabilitation shoe promises to alter the user‟s gait as a split belt treadmill does, and to be mechanically stable operating without any external power sources. I designed and constructed a new motion controlled gait enhancing mobile shoe that improves the previous version‟s drawbacks. While mimicking the asymmetric gait motion experienced on a split-belt treadmill, this version of the GEMS has motion that is continuous, smooth, and regulated with on-board electronics. An interesting aspect of this new design is the Archimedean spiral wheel shape that redirects the wearer‟s downward force into a horizontal backward motion. The design is passive and does not utilize any motors and actuators. Its motion is only regulated by a small magnetic pthesis brake. Initial tests show the shoe operates as desired, but further experimentation is needed to evaluate the long-term after-effects.

Mitral valve repair, the preferred method of treating mitral regurgitation, is a demanding surgical procedure consisting of the resection and approximation of valve tissue. Operating on an arrested heart, the clinician is forced to predict closed valve shape and the effect of surgical modifications. The valve's complex morphology makes this a difficult task, and as a result, the procedure is underperformed by less experienced surgeons in lieu of the simpler, less effective valve replacement. / Engineering and Applied Sciences

Haptic-based Virtual Reality (VR) applications have many merits. What is still obscure, from the designer’s perspective of these applications, is the experience the users will undergo when they use the VR system. Quality of Experience (QoE) is an evaluation metric from the user’s perspective that unfortunately has received limited attention from the research community. Assessing the QoE of VR applications reflects the amount of overall satisfaction and benefits gained from the application in addition to laying the foundation for ideal user-centric design in the future. In this thesis, we address certain issues and concerns regarding QoE of virtual environments. In essence, we propose a taxonomy for the evaluation of the QoE for multimedia applications and in particular VR applications. The taxonomy classifies QoE related parameters into groups. The groups’ organization is generated from the definition we have adopted for the QoE which is the Quality of Service (QoS) plus the user experience (UX). We model this taxonomy using first mathematical modeling based on weighted averages and then a Fuzzy logic Inference System (FIS) to quantitatively measure the QoE of haptic virtual environments. We test both models conducting user study analysis to evaluate the QoE of a VR application. These models serve as engines that facilitate the calculation of QoE with minimal amount of users. We specifically attend to the issue of the new media, haptics, within the context of increasing the QoE of virtual environments (VE). This special attention is important for comparing the effect of tactile and kinesthetic feedback on the QoE. In accordance, we investigate a particular topic that seems to have a colossal effect on QoE throughout our analysis, which is fatigue. Our analysis involved users' studies since the main focus is on the user. The QoE for virtual environments is in its primary stages. This thesis tackles issues that are vital in dealing with and understanding the importance of QoE. The various results suggest a positive user's disposition toward haptics and virtual environments, yet there will always be obstacles and challenges such as fatigue that if minimized will enhance the QoE of haptic-based applications.