999 resultados para haptic devices


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Utilizing user-centred system design and evaluation method has become an increasingly important tool to foster better usability in the field of virtual environments (VEs). In recent years, although it is still the norm that designers and developers are concerning the technological advancement and striving for designing impressive multimodal multisensory interfaces, more and more awareness are aroused among the development team that in order to produce usable and useful interfaces, it is essential to have users in mind during design and validate a new design from users' perspective. In this paper, we describe a user study carried out to validate a newly developed haptically enabled virtual training system. By taking consideration of the complexity of individual differences on human performance, adoption and acceptance of haptic and audio-visual I/O devices, we address how well users learn, perform, adapt to and perceive object assembly training. We also explore user experience and interaction with the system, and discuss how multisensory feedback affects user performance, perception and acceptance. At last, we discuss how to better design VEs that enhance users perception, their interaction and motor activity.

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Currently, the micro-robotic cell injection procedure is performed manually by expert human bio-operators. In order to be proficient at the task, lengthy and expensive dedicated training is required. As such, effective specialized training systems for this procedure can prove highly beneficial. This paper presents a comprehensive review of haptic technology relevant to cell injection training and discusses the feasibility of developing such training systems, providing researchers with an inclusive resource enabling the application of the presented approaches, or extension and advancement of the work. A brief explanation of cell injection and the challenges associated with the procedure are first presented. Important skills, such as accuracy, trajectory, speed and applied force, which need to be mastered by the bio-operator in order to achieve successful injection, are then discussed. Then an overview of various types of haptic feedback, devices and approaches is presented. This is followed by discussion on the approaches to cell modeling. Discussion of the application of haptics to skills training across various fields and haptically-enabled virtual training systems evaluation are then presented. Finally, given the findings of the review, this paper concludes that a haptically-enabled virtual cell injection training system is feasible and recommendations are made to developers of such systems.

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To perform advanced manipulation of remote environments such as grasping, more than one finger is required implying higher requirements for the control architecture. This paper presents the design and control of a modular 3-finger haptic device that can be used to interact with virtual scenarios or to teleoperate dexterous remote hands. In a modular haptic device, each module allows the interaction with a scenario by using a single finger; hence, multi-finger interaction can be achieved by adding more modules. Control requirements for a multifinger haptic device are analyzed and new hardware/software architecture for these kinds of devices is proposed. The software architecture described in this paper is distributed and the different modules communicate to allow the remote manipulation. Moreover, an application in which this haptic device is used to interact with a virtual scenario is shown.

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This paper presents the implementation of a robust grasp mapping between a 3-finger haptic device (master) and a robotic hand (slave). Mapping is based on a grasp equivalence defined considering the manipulation capabilities of the master and slave devices. The metrics that translate the human hand gesture to the robotic hand workspace are obtained through an analytical user study. This allows a natural control of the robotic hand. The grasp mapping is accomplished defining 4 control modes that encapsulate all the grasps gestures considered.

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When teaching students with visual impairments educators generally rely on tactile tools to depict visual mathematical topics. Tactile media, such as embossed paper and simple manipulable materials, are typically used to convey graphical information. Although these tools are easy to use and relatively inexpensive, they are solely tactile and are not modifiable. Dynamic and interactive technologies such as pin matrices and haptic pens are also commercially available, but tend to be more expensive and less intuitive. This study aims to bridge the gap between easy-to-use tactile tools and dynamic, interactive technologies in order to facilitate the haptic learning of mathematical concepts. We developed an haptic assistive device using a Tanvas electrostatic touchscreen that provides the user with multimodal (haptic, auditory, and visual) output. Three methodological steps comprise this research: 1) a systematic literature review of the state of the art in the design and testing of tactile and haptic assistive devices, 2) a user-centered system design, and 3) testing of the system’s effectiveness via a usability study. The electrostatic touchscreen exhibits promise as an assistive device for displaying visual mathematical elements via the haptic modality.

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The release of ultrafine particles (UFP) from laser printers and office equipment was analyzed using a particle counter (FMPS; Fast Mobility Particle Sizer) with a high time resolution, as well as the appropriate mathematical models. Measurements were carried out in a 1 m³ chamber, a 24 m³ chamber and an office. The time-dependent emission rates were calculated for these environments using a deconvolution model, after which the total amount of emitted particles was calculated. The total amounts of released particles were found to be independent of the environmental parameters and therefore, in principle, they were appropriate for the comparison of different printers. On the basis of the time-dependent emission rates, “initial burst” emitters and constant emitters could also be distinguished. In the case of an “initial burst” emitter, the comparison to other devices is generally affected by strong variations between individual measurements. When conducting exposure assessments for UFP in an office, the spatial distribution of the particles also had to be considered. In this work, the spatial distribution was predicted on a case by case basis, using CFD simulation.

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Field and laboratory measurements identified a complex relationship between odour emission rates provided by the US EPA dynamic emission chamber and the University of New South Wales wind tunnel. Using a range of model compounds in an aqueous odour source, we demonstrate that emission rates derived from the wind tunnel and flux chamber are a function of the solubility of the materials being emitted, the concentrations of the materials within the liquid; and the aerodynamic conditions within the device – either velocity in the wind tunnel, or flushing rate for the flux chamber. The ratio of wind tunnel to flux chamber odour emission rates (OU m-2 s) ranged from about 60:1 to 112:1. The emission rates of the model odorants varied from about 40:1 to over 600:1. These results may provide, for the first time, a basis for the development of a model allowing an odour emission rate derived from either device to be used for odour dispersion modelling.

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This research explores gestures used in the context of activities in the workplace and in everyday life in order to understand requirements and devise concepts for the design of gestural information applicances. A collaborative method of video interaction analysis devised to suit design explorations, the Video Card Game, was used to capture and analyse how gesture is used in the context of six different domains: the dentist's office; PDA and mobile phone use; the experimental biologist's laboratory; a city ferry service; a video cassette player repair shop; and a factory flowmeter assembly station. Findings are presented in the form of gestural themes, derived from the tradition of qualitative analysis but bearing some similarity to Alexandrian patterns. Implications for the design of gestural devices are discussed.

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Computer aided joint replacement surgery has become very popular during recent years and is being done in increasing numbers all over the world. The accuracy of the system depends to a major extent, on accurate registration and immobility of the tracker attachment devices to the bone. This study was designed to asses the forces needed to displace the tracker attachment devices in the bone simulators. Bone simulators were used to maintain the uniformity of the bone structure during the study. The fixation devices tested were 3mm diameter self drilling, self tapping threaded pin, 4mm diameter self tapping cortical threaded pin, 5mm diameter self tapping cancellous threaded pin and a triplanar fixation device ‘ortholock’ used with three 3mm pins. All the devices were tested for pull out, translational and rotational forces in unicortical and bicortical fixation modes. Also tested was the normal bang strength and forces generated by leaning on the devices. The forces required to produce translation increased with the increasing diameter of the pins. These were 105N, 185N, and 225N for the unicortical fixations and 130N, 200N, 225N for the bicortical fixations for 3mm, 4mm and 5mm diameter pins respectively. The forces required to pull out the pins were 1475N, 1650N, 2050N for the unicortical, 1020N, 3044N and 3042N for the bicortical fixated 3mm, 4mm and 5mm diameter pins. The ortholock translational and pull out strength was tested to 900N and 920N respectively and still it did not fail. Rotatory forces required to displace the tracker on pins was to the magnitude of 30N before failure. The ortholock device had rotational forces applied up to 135N and still did not fail. The manual leaning forces and the sudden bang forces generated were of the magnitude of 210N and 150N respectively. The strength of the fixation pins increases with increasing diameter from three to five mm for the translational forces. There is no significant difference in pull out forces of four mm and five mm diameter pins though it is more that the three mm diameter pins. This is because of the failure of material at that stage rather than the fixation device. The rotatory forces required to displace the tracker are very small and much less that that can be produced by the surgeon or assistants in single pins. Although the ortholock device was tested to 135N in rotation without failing, one has to be very careful not to put any forces during the operation on the tracker devices to ensure the accuracy of the procedure.

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This paper reports on a six month longitudinal study exploring people’s personal and social emotional experience with Portable Interactive Devices (PIDs). The study is concerned with the experience design approach and based on the theoretical framework of Activity Theory. The focus is on emotional experiences and how artefacts mediate and potentially enhance this experience. The outcomes of the study identified interesting aspects of PID interaction. Findings revealed people interact with PIDs emotionally both at a personal and a social level, supporting previous studies. Further, the social level impacts significantly on the emotional experience attained. If negative social experiences exceeded negative personal experiences the emotional experience was constant over six months. If negative personal experiences surpassed negative social experiences the emotional experience was varied over six months. The findings are discussed in regards to their significance to the field of design, their implication for future PID design and future research directions.

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People in developed countries are living longer with the help of medical advances. Literature has shown that older people prefer to stay independent and live at home for as long as possible. Therefore, it is important to find out how to best accommodate and assist them in maintaining quality of life and independence as well as easing human resources. Researchers have claimed that assistive devices assist in older people’s independence, however, only a small number of studies regarding the efficiency of assistive devices have been undertaken of which several have stated that devices are not being used. The overall aim of this research was to identify whether the disuse and ineffectiveness of assistive devices are related to change in abilities or related to the design of the devices. The objective was to gather information from the elderly; to identify what assistive devices are being used or not used and to gain an understanding on their attitudes towards assistive devices. Research was conducted in two phases. The initial phase of the research was conducted with the distribution of questionnaires to people over the age of fifty that asked general questions and specific questions on type of devices being used. Phase One was followed on by Phase Two, where participants from Phase One who had come in contact with assistive devices were invited to participate in a semi-structured interview. Questions were put forth to the interviewee on their use of and attitudes towards assistive devices. Findings indicated that the reasons for the disuse in assistive devices were mostly design related; bulkiness, reliability, performance of the device, difficulty of use. The other main reason for disuse was socially related; elderly people preferred to undertake activities on their own and only use a device as a precaution or when absolutely necessary. They would prefer not having to rely on the devices. Living situation and difference in gender did not affect the preference for the use of assistive devices over personal assistance. The majority strongly supported the idea of remaining independent for as long as possible. In conclusion, this study proposes that through these findings, product designers will have a better understanding of the requirements of an elderly user. This will enable the designers to produce assistive devices that are more practical, personalised, reliable, easy to use and tie in with the older people’s environments. Additional research with different variables is recommended to further justify these findings.

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We present a novel, simple and effective approach for tele-operation of aerial robotic vehicles with haptic feedback. Such feedback provides the remote pilot with an intuitive feel of the robot’s state and perceived local environment that will ensure simple and safe operation in cluttered 3D environments common in inspection and surveillance tasks. Our approach is based on energetic considerations and uses the concepts of network theory and port-Hamiltonian systems. We provide a general framework for addressing problems such as mapping the limited stroke of a ‘master’ joystick to the infinite stroke of a ‘slave’ vehicle, while preserving passivity of the closed-loop system in the face of potential time delays in communications links and limited sensor data