727 research outputs found
Perception of Compliance in Laparoscopic Surgery
Laparoscopic surgery provides major benefits to patients in terms of decreased pain and post-operative hospital stays, but also increases their risks of intra-operative injuries because of the reduction in feedback in the tactile and visual channels compared to open surgery. Although the limitations of laparoscopy have been studied, the specific role of force feedback in laparoscopic surgery performance is not well understood.
The purpose of this thesis is to determine the effect of force feedback on the ability to accurately discriminate tissue compliance by comparing subjective tissue softness assessment, force output, and subjective force assessment, in conventional and laparoscopic setups. The experimental trials involved eleven participants providing evaluations for a range of compliant samples, and analyzed their force output as well as their subjective evaluation of force output.
The results of this investigation show that the accuracy of compliance discrimination is worse when using indirect probing compared to direct probing, and that the force used in direct probing is lower than the indirect scenario. Further, the subjective assessment of force output in direct probing is not significantly different compared to indirect probing. Further research involving more replication, expert of laparoscopy, and a focus on grip force are recommended to better understand our awareness of the subjective force output
Sensory Communication
Contains table of contents on Section 2, an introduction, reports on eleven research projects and a list of publications.National Institutes of Health Grant 5 R01 DC00117National Institutes of Health Grant 5 R01 DC00270National Institutes of Health Contract 2 P01 DC00361National Institutes of Health Grant 5 R01 DC00100National Institutes of Health Contract 7 R29 DC00428National Institutes of Health Grant 2 R01 DC00126U.S. Air Force - Office of Scientific Research Grant AFOSR 90-0200U.S. Navy - Office of Naval Research Grant N00014-90-J-1935National Institutes of Health Grant 5 R29 DC00625U.S. Navy - Office of Naval Research Grant N00014-91-J-1454U.S. Navy - Office of Naval Research Grant N00014-92-J-181
Haptics: Science, Technology, Applications
This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility
Haptics: Science, Technology, Applications
This open access book constitutes the proceedings of the 13th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2022, held in Hamburg, Germany, in May 2022. The 36 regular papers included in this book were carefully reviewed and selected from 129 submissions. They were organized in topical sections as follows: haptic science; haptic technology; and haptic applications
Bringing the Physical to the Digital
This dissertation describes an exploration of digital tabletop interaction styles, with the ultimate goal of informing the design of a new model for tabletop interaction. In the context of this thesis the term digital tabletop refers to an emerging class of devices that afford many novel ways of interaction with the digital. Allowing users to directly touch information presented on large,
horizontal displays. Being a relatively young field, many developments are in flux; hardware and software change at a fast pace and many interesting alternative approaches are available at the same time. In our research we are especially interested in systems that are capable of sensing multiple contacts (e.g., fingers) and richer information such as the outline of whole hands or other physical objects. New sensor hardware enable new ways to interact with the digital. When embarking into the research for this thesis, the question which interaction styles could
be appropriate for this new class of devices was a open question, with many equally promising answers.
Many everyday activities rely on our hands ability to skillfully control and manipulate physical objects. We seek to open up different possibilities to exploit our manual dexterity and provide users with richer interaction possibilities. This could be achieved through the use of physical objects as input mediators or through virtual interfaces that behave in a more realistic fashion.
In order to gain a better understanding of the underlying design space we choose an approach organized into two phases. First, two different prototypes, each representing a specific interaction style – namely gesture-based interaction and tangible interaction – have been implemented. The flexibility of use afforded by the interface and the level of physicality afforded by the interface elements are introduced as criteria for evaluation. Each approaches’ suitability to support the
highly dynamic and often unstructured interactions typical for digital tabletops is analyzed based
on these criteria.
In a second stage the learnings from these initial explorations are applied to inform the design of a novel model for digital tabletop interaction. This model is based on the combination of rich multi-touch sensing and a three dimensional environment enriched by a gaming physics simulation. The proposed approach enables users to interact with the virtual through richer quantities such as collision and friction. Enabling a variety of fine-grained interactions using multiple fingers, whole hands and physical objects.
Our model makes digital tabletop interaction even more “natural”. However, because the interaction – the sensed input and the displayed output – is still bound to the surface, there is a fundamental limitation in manipulating objects using the third dimension. To address this issue,
we present a technique that allows users to – conceptually – pick objects off the surface and control their position in 3D. Our goal has been to define a technique that completes our model for on-surface interaction and allows for “as-direct-as possible” interactions. We also present
two hardware prototypes capable of sensing the users’ interactions beyond the table’s surface.
Finally, we present visual feedback mechanisms to give the users the sense that they are actually lifting the objects off the surface.
This thesis contributes on various levels. We present several novel prototypes that we built and evaluated. We use these prototypes to systematically explore the design space of digital tabletop interaction. The flexibility of use afforded by the interaction style is introduced as criterion alongside the user interface elements’ physicality. Each approaches’ suitability to support the
highly dynamic and often unstructured interactions typical for digital tabletops are analyzed. We present a new model for tabletop interaction that increases the fidelity of interaction possible in
such settings. Finally, we extend this model so to enable as direct as possible interactions with
3D data, interacting from above the table’s surface
Haptics in Robot-Assisted Surgery: Challenges and Benefits
Robotic surgery is transforming the current surgical practice, not only by improving the conventional surgical methods but also by introducing innovative robot-enhanced approaches that broaden the capabilities of clinicians. Being mainly of man-machine collaborative type, surgical robots are seen as media that transfer pre- and intra-operative information to the operator and reproduce his/her motion, with appropriate filtering, scaling, or limitation, to physically interact with the patient. The field, however, is far from maturity and, more critically, is still a subject of controversy in medical communities. Limited or absent haptic feedback is reputed to be among reasons that impede further spread of surgical robots. In this paper objectives and challenges of deploying haptic technologies in surgical robotics is discussed and a systematic review is performed on works that have studied the effects of providing haptic information to the users in major branches of robotic surgery. It has been tried to encompass both classical works and the state of the art approaches, aiming at delivering a comprehensive and balanced survey both for researchers starting their work in this field and for the experts
Haptics: Science, Technology, Applications
This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility
Factors of Micromanipulation Accuracy and Learning
Micromanipulation refers to the manipulation under a microscope in order to
perform delicate procedures. It is difficult for humans to manipulate objects
accurately under a microscope due to tremor and imperfect perception, limiting
performance. This project seeks to understand factors affecting accuracy in
micromanipulation, and to propose strategies for learning improving accuracy.
Psychomotor experiments were conducted using computer-controlled setups to
determine how various feedback modalities and learning methods can influence
micromanipulation performance. In a first experiment, static and motion accuracy
of surgeons, medical students and non-medical students under different
magniification levels and grip force settings were compared. A second experiment
investigated whether the non-dominant hand placed close to the target can contribute
to accurate pointing of the dominant hand. A third experiment tested a
training strategy for micromanipulation using unstable dynamics to magnify motion
error, a strategy shown to be decreasing deviation in large arm movements.
Two virtual reality (VR) modules were then developed to train needle grasping
and needle insertion tasks, two primitive tasks in a microsurgery suturing
procedure. The modules provided the trainee with a visual display in stereoscopic
view and information on their grip, tool position and angles. Using the
VR module, a study examining effects of visual cues was conducted to train tool
orientation. Results from these studies suggested that it is possible to learn and
improve accuracy in micromanipulation using appropriate sensorimotor feedback
and training
Change blindness: eradication of gestalt strategies
Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task
The cortical integration of tactile sensation in complex regional pain syndrome
Much is still unknown about sensory and perceptual changes in the cortex associated with complex regional pain syndrome (CRPS). This PhD aimed to investigate cortical integration of tactile sensation of the hand specifically the fingers, and how this might be altered in CRPS.
A match-paired cross-sectional design was used in a series of neuroimaging and psychophysical studies on patients with unilateral upper limb CRPS (n=21). Clinical characteristics were described and compared with age, gender and hand dominance matched controls (Chapter 2). Methodological improvements for fine-grained fingertip mapping in the primary somatosensory cortex were piloted (n=1) in two separate experiments (Chapter 3). Single fingertip stimulation versus bilateral simultaneous fingertip stimulation was compared using phase encoded functional magnetic resonance imaging (fMRI). Fine-grained fMRI maps of the fingertips in S1 in CRPS were described. Structural morphometry measures underlying the functional S1 fingertip maps including cortical thickness were analysed with step-wise mixed modelling with a priori hypothesised effects including hand dominance and medication. Patient characteristics including pain- related measures were correlated with morphometry measures (Chapter 4). A new finger illusion experiment was applied for the first time in patients with CRPS (Chapter 5).
The pilot found that bilateral tactile stimulus was most suitable for use in CRPS and had superior time efficiency. Disordered S1 functional fingertip maps in CRPS with no distinct pattern were found using this stimulus, when compared to the orderly homogenous map pattern in healthy controls. These functional imaging observations were strengthened by the key finding that increased cortical thickness underlying these maps together with hand dominance predicted group (CRPS versus healthy controls) membership. An abnormal finger illusion response in CRPS compared to controls, also suggests a disruption to normal efficiencies of bimanual hand representation cortically, not previously reported.
In conclusion, disruption to cortical integration of tactile sensation in CRPS is suggested from the results. These changes also suggest cortical representation of differences in hand dominance rather than CRPS-sided-differences predicted those with CRPS in this study. Future directions to test these suggested cortically mediated changes in CRPS were explored
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