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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Haptic emulation of hard surfaces with applications to orthopaedic surgery

Hungr, Nikolai Anthony 05 1900 (has links)
A generally accepted goal in orthopaedic surgery today is to maximize conservation of tissue and reduce tissue damage. Bone-conserving implants have bone-mating surfaces that reproduce the natural curvature of bone structures, requiring less bone removal. No small, reliable, inexpensive and universal bone sculpting technique currently exists, however, that can both create and accurately align such complex surfaces. The goal of this thesis was to develop a haptic hard surface emulation mechanism that could be applied to curvilinear bone sculpting using a surgical robot. A novel dynamic physical constraint concept was developed that is able to emulate realistic hard constraints, smooth surface following, and realistic surface rigidity, while allowing complete freedom of motion away from the constraints. The concept was verified through the construction of a two-link manipulator prototype. Tests were run on nine users that involved each user tracing out five different virtual surfaces on a drawing surface using the prototype. The primary purposes of prototype testing were to obtain subjective data on how effectively the dynamic physical constraint concept simulates simple surfaces, to assess how it reacts to typical user interactions and to identify any unexpected behaviour. Users were 100% satisfied with the prototype’s ability to emulate realistic and stiff hard surfaces and with its ease of manipulation. The amount of incursion into each of the virtual surfaces by all the users was measured to assess the precision of the system with the goal of deciding whether this new haptic concept should be further developed specifically for precision applications such as surgery. For curvilinear surfaces, 90% of the cumulative distribution of the measured data was less than 2mm, while for linear surfaces it was less than 6mm. Four behavioural effects were noticed: lateral deflection, reverse ‘stickiness’, hysteresis and instability in certain areas. These effects were studied in detail to determine how to either eliminate them or to minimize them through system design optimization. A computer simulation was also used to model the behaviour of the prototype and to gain further understanding of these effects. These analyses showed that the concept can be successfully used in curvilinear bone sculpting.
22

Mechanical linkage design for haptic rehabilitation and development of fine motor skills /

Streng, Bradley Taylor. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 68-71). Also available on the World Wide Web.
23

Admittance and impedance haptic control for realization of digital clay as an effective human machine interface (HMI) device

Ngoo, Cheng Shu. January 2009 (has links)
Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Book, Wayne; Committee Member: Glezer, Ari; Committee Member: Sadegh, Nader. Part of the SMARTech Electronic Thesis and Dissertation Collection.
24

A methodology for situated and effective design of haptic devices

Sun, Xuan January 2017 (has links)
The realism of virtual surgery through a surgical simulator depends largely on the precision and reliability of the haptic device. The quality of perception depends on the design of the haptic device, which presents a complex design task due to the multi-criteria and conflicting character of the functional and performance requirements. In the model-based evaluation of the performance criteria of a haptic device, the required computational resources increase with the complexity of the device structure as well as with the increased level of detail that is created in the detail design phases. Due to uncertain requirements and a significant knowledge gap, the design task is fuzzy and more complex in the early design phases. The goal of this thesis is to propose a situated, i.e., flexible, scalable and efficient, methodology for multi-objective and multi-disciplinary design optimization of high-performing 6-DOF haptic devices. The main contributions of this thesis are: 1. A model-based and simulation-driven engineering design methodology and a flexible pilot framework are proposed for design optimization of high-performing haptic devices. The multi-disciplinary design optimization method was utilized to balance the conflicting criteria/requirements of a multi-domain design case and to solve the design optimization problems concurrently. 2. A multi-tool framework is proposed. The framework integrates metamodel-based design optimization with complementary engineering tools from different software vendors, which was shown to significantly reduce the total computationally effort. 3. The metamodeling methods and sampling sizes for specific performance indices found from case studies were shown to be applicable and usable for several kinds of 6-degrees-of-freedom haptic devices. 4. The multi-tool framework and the assisting methodology were further developed to enable computationally efficient and situated design multi-objective optimization of high-performing haptic devices. The design-of-experiment (DOE) and metamodeling techniques are integrated with the optimization process in the framework as an option to solve the design optimization case with a process that depends on the present system complexity. / <p>QC 20171108</p>
25

Haptic emulation of hard surfaces with applications to orthopaedic surgery

Hungr, Nikolai Anthony 05 1900 (has links)
A generally accepted goal in orthopaedic surgery today is to maximize conservation of tissue and reduce tissue damage. Bone-conserving implants have bone-mating surfaces that reproduce the natural curvature of bone structures, requiring less bone removal. No small, reliable, inexpensive and universal bone sculpting technique currently exists, however, that can both create and accurately align such complex surfaces. The goal of this thesis was to develop a haptic hard surface emulation mechanism that could be applied to curvilinear bone sculpting using a surgical robot. A novel dynamic physical constraint concept was developed that is able to emulate realistic hard constraints, smooth surface following, and realistic surface rigidity, while allowing complete freedom of motion away from the constraints. The concept was verified through the construction of a two-link manipulator prototype. Tests were run on nine users that involved each user tracing out five different virtual surfaces on a drawing surface using the prototype. The primary purposes of prototype testing were to obtain subjective data on how effectively the dynamic physical constraint concept simulates simple surfaces, to assess how it reacts to typical user interactions and to identify any unexpected behaviour. Users were 100% satisfied with the prototype’s ability to emulate realistic and stiff hard surfaces and with its ease of manipulation. The amount of incursion into each of the virtual surfaces by all the users was measured to assess the precision of the system with the goal of deciding whether this new haptic concept should be further developed specifically for precision applications such as surgery. For curvilinear surfaces, 90% of the cumulative distribution of the measured data was less than 2mm, while for linear surfaces it was less than 6mm. Four behavioural effects were noticed: lateral deflection, reverse ‘stickiness’, hysteresis and instability in certain areas. These effects were studied in detail to determine how to either eliminate them or to minimize them through system design optimization. A computer simulation was also used to model the behaviour of the prototype and to gain further understanding of these effects. These analyses showed that the concept can be successfully used in curvilinear bone sculpting. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
26

Design of a Testbed for Haptic Devices Used by Surgical Simulators / Konstruktion av en testbänk för haptiska instrument använda för simulering av kirurgi

Udvardy, Zoltán January 2017 (has links)
Nowadays surgery simulations are aiming to apply not just visual effects but forcefeedback as well. To carry out force feedback, haptic devices are utilized that are mostlycommercial products for general purposes. Some of the haptic device features are moreimportant than others in case of surgery simulator use. The precision of the output forcemagnitude is one such property. The specifications provided by haptic devicemanufacturers are lacking details on device characteristics, known to cause difficulties inplanning of accurate surgery simulations.This project shows the design of a testbed that is capable of measuring the precision ofoutput forces within the haptic devices’ workspace. With the testbed, a set ofmeasurements can be run on different haptic devices, giving as a result a betterknowledge of the utilized device. This knowledge aids the design of more precise andrealistic surgery simulations.
27

Tactile display for mobile interaction

Pasquero, Jerome. January 2008 (has links)
No description available.
28

Mobile music touch: using haptic stimulation for passive rehabilitation and learning

Markow, Tanya Thais 30 March 2012 (has links)
Hand rehabilitation after injury or illness may allow a patient to regain full or at least partial use of a limb. However, rehabilitation often requires the patient to perform multiple repetitions of motions. While absolutely essential to regaining usage, such exercises are not always mentally engaging or enjoyable for the patient. The loss or degradation of the use of the hands can cause considerable loss of independence. In this dissertation, we present Mobile Music Touch (MMT), a wireless glove paired with a computing device, such as a laptop, smart phone, or MP3 player. The MMT system plays a song, while also "tapping" the fingers using vibration motors to indicate the correct finger to use to play the song on a piano keyboard. Learning a new skill or activity without active focus, an idea called Passive Haptic Learning(PHL) may allow an individual to learn one skill through their sense of touch while performing another, unrelated activity. Most rehabilitation activities are active in nature, requiring the focused participation of the injured person. Passive rehabilitation is the idea that some technologies and activities may bring about beneficial changes without the active engagement of the injured person. In order to study the concepts of PHL and PHR, we propose the Mobile Music Touch (MMT) system. We show that using passive rehabilitation in conjunction with the active rehabilitation of piano playing will bring about a greater degree of improvement in the hands than that achieved using only active rehabilitation. This dissertation research makes three unique contributions. First, we demonstrate that Passive Haptic Learning (PHL) using just the sense of touch is feasible and provides a form of learning and reinforcement of learned skills and tasks. Second, we identify the attributes and design features of a glove suited for long term wear by persons who use a manual wheelchair for mobility. Third, we show that Passive Haptic Rehabilitation (PHR) is possible using vibrotactile stimulation of the hands in persons classified as tetraplegic due to incomplete spinal cord injury.
29

Designing tangible tabletop interactions to support the fitting process in modeling biological systems

Wu, Chih-Sung 13 November 2012 (has links)
This thesis aims to explore how to physically interact with computational models on an interactive tabletop display. The research began with the design and implementation of several prototype systems. The research of the prototype systems showed that tangible interactions on interactive tabletops have the potential to be more effective on some tasks than traditional interfaces that use screen displays, keyboards and mice. The prototype work shaped the research to focus on the effectiveness of adopting tangible interactions on interactive tabletops. To substantiate the thesis claims, this thesis develops an interactive tabletop application, Pathways, to support the fitting process in modeling biological systems. Pathways supports the concepts of Tangible User Interfaces (TUIs) and tabletop visualizations. It realizes real-time simulation of models and provides comparisons of simulation results with experimental data on the tabletop. It also visualizes the simulation of the model with animations. In addition to that, Pathways introduces a new visualization to help systems biologists quickly compare the simulation results. This thesis provides the quantitative and qualitative evaluation results of Pathways. The evidence showed that using tangible interactions to control numerical values is practical. The results also showed that in experimental conditions users achieved better fitting results and faster fitting results on Pathways than the control group, which used the systems biologists' current tools. The results further suggested that it is possible to recruit non-experts to perform the fitting tasks that are usually done by professional systems biologists.
30

MAPPING STRATEGIES OF DISTANCE INFORMATION BASED ON CONTINUOUS VIBROTACTILE AMPLITUDE AND FREQUENCY VARIATION - THESIS JOHANNES F. RUESCHEN

Johannes Friedrich Rueschen (14238116) 09 December 2022 (has links)
<p>Our study investigates how different mapping strategies of distance information affect performance in an object exploration task with a teleoperated virtual robot. The task was to find an object inside a backpack using a simulated robotic gripper. A virtual proximity sensor tracked the distance between the tip of the gripper and the object. The distance was conveyed as a vibration pattern on the users index finger. This is the only information that was received to guide the user towards the object. The goal was to locate the hidden object by moving the tip of the gripper as quickly and as closely towards the object as possible without touching it. We implemented three different mapping strategies that utilized continuous frequency and amplitude variations of sinusoidal vibrations to encode distance. The present study provides empirical evidence that the mapping strategy can affect accuracy when approaching an object. We found that linear feedback sensations help to sense the rate of approach. Non- linear feedback perception can provide cues that enable more accurate approximation of the absolute distance. We found that experienced participants could selectively attend to and integrate frequency and intensity cues when both modalities are changed simultaneously. Inexperienced participants were not able to make this distinction and found it difficult to interpret such a signal. They preferred one-dimensional changes.</p>

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