92,358 research outputs found
Outcomes of a virtual-reality simulator-training programme on basic surgical skills in robot-assisted laparoscopic surgery
Background The utility of the virtual-reality robotic simulator in training
programmes has not been clearly evaluated. Our aim was to evaluate the
impact of a virtual-reality robotic simulator-training programme on basic
surgical skills.
Methods A simulator-training programme in robotic surgery, using the da
Vinci Skills Simulator, was evaluated in a population including junior and seasoned
surgeons, and non-physicians. Their performances on robotic dots and
suturing-skin pod platforms before and after virtual-simulation training were
rated anonymously by surgeons experienced in robotics.
Results 39 participants were enrolled: 14 medical students and residents in
surgery, 14 seasoned surgeons, 11 non-physicians. Junior and seasoned
surgeons’ performances on platforms were not significantly improved after
virtual-reality robotic simulation in any of the skill domains, in contrast to
non-physicians.
Conclusions The benefits of virtual-reality simulator training on several
tasks to basic skills in robotic surgery were not obvious among surgeons
in our initial and early experience with the simulator
VPLanet: The Virtual Planet Simulator
We describe a software package called VPLanet that simulates fundamental
aspects of planetary system evolution over Gyr timescales, with a focus on
investigating habitable worlds. In this initial release, eleven physics modules
are included that model internal, atmospheric, rotational, orbital, stellar,
and galactic processes. Many of these modules can be coupled simultaneously to
simulate the evolution of terrestrial planets, gaseous planets, and stars. The
code is validated by reproducing a selection of observations and past results.
VPLanet is written in C and designed so that the user can choose the physics
modules to apply to an individual object at runtime without recompiling, i.e.,
a single executable can simulate the diverse phenomena that are relevant to a
wide range of planetary and stellar systems. This feature is enabled by
matrices and vectors of function pointers that are dynamically allocated and
populated based on user input. The speed and modularity of VPLanet enables
large parameter sweeps and the versatility to add/remove physical phenomena to
assess their importance. VPLanet is publicly available from a repository that
contains extensive documentation, numerous examples, Python scripts for
plotting and data management, and infrastructure for community input and future
development.Comment: 75 pages, 34 figures, 10 tables, accepted to the Proceedings of the
Astronomical Society of the Pacific. Source code, documentation, and examples
available at https://github.com/VirtualPlanetaryLaboratory/vplane
Comparing Virtual Reality to Conventional Simulator Visuals: Effects of Peripheral Visual Cues in Roll-Axis Tracking Tasks
This paper compares the effects of peripheral visual cues on manual control between a conventional fixed-base simulator and virtual reality. The results were also compared with those from a previous experiment conducted in a motion-base simulator. Fifteen participants controlled a system with second-order dynamics in a disturbance-rejection task. Tracking performance, control activity, simulator sickness questionnaire answers, and biometrics were collected. Manual control behavior was modeled for the first time in a virtual reality environment. Virtual reality did not degrade participants manual control performance or alter their control behavior. However, peripheral cues were significantly more effective in virtual reality. Control activity decreased for all conditions with peripheral cues. The trends introduced by the peripheral visual cues from the previous experiment were replicated. Finally, VR was not more nauseogenic than the conventional simulator. These results suggest that virtual reality might be a good alternative to conventional fixed-base simulators for training manual control skills
The Virtual Armory: Virtual Jousting Simulator
This project presents a sport of the past using current technologies to recreate the experience of jousting for visitors to the Higgins Armory Museum. Through collaboration with museum staff, intensive historical research, and a rigorous, iterative software development cycle, the project team developed a jousting simulation using technologies that incorporated Java, Flash, TCP/IP sockets, Bluetooth and XML. Nintendo Wii remotes, embedded in a lance stub and to horse reins, were also used to further simulate realism in the user-application interface
Initial validation of a virtual-reality learning environment for prostate biopsies: realism matters!
: Introduction-objectives: A virtual-reality learning environment dedicated
to prostate biopsies was designed to overcome the limitations of current
classical teaching methods. The aim of this study was to validate reliability,
face, content and construct of the simulator. Materials and methods: The
simulator is composed of a) a laptop computer, b) a haptic device with a stylus
that mimics the ultrasound probe, c) a clinical case database including three
dimensional (3D) ultrasound volumes and patient data and d) a learning
environment with a set of progressive exercises including a randomized 12-core
biopsy procedure. Both visual (3D biopsy mapping) and numerical (score)
feedback are given to the user. The simulator evaluation was conducted in an
academic urology department on 7 experts and 14 novices who each performed a
virtual biopsy procedure and completed a face and content validity
questionnaire. Results: The overall realism of the biopsy procedure was rated
at a median of 9/10 by non-experts (7.1-9.8). Experts rated the usefulness of
the simulator for the initial training of urologists at 8.2/10 (7.9-8.3), but
reported the range of motion and force feedback as significantly less realistic
than novices (p=0.01 and 0.03 respectively). Pearson's r correlation
coefficient between correctly placed biopsies on the right and left side of the
prostate for each user was 0.79 (p<0.001). The 7 experts had a median score of
64% (59-73), and the 14 novices a median score of 52% (43-67), without reaching
statistical significance (p=0,19). Conclusion: The newly designed virtual
reality learning environment proved its versatility and its reliability, face
and content were validated. Demonstrating the construct validity will require
improvements to the realism and scoring system used
Weighting Waiting: Evaluating the Perception of In-Vehicle Travel Time Under Moving and Stopped Conditions
This paper describes experiments comparing traditional computer administered stated preference with virtual experience stated preference to ascertain how people value stopped delay compared with stop-and- go or freeflow traffic. The virtual experience stated preference experiments were conducted using a wrap around driving simulator. The two methods produced two different results, with the traditional computer assisted stated preference suggesting that ramp delay is 1.6 Ð 1.7 times more onerous than freeway time, while the driving simulator based virtual experience stated preference suggested that freeway delay is more onerous than ramp delay. Several reasons are hypothesized to explain the differences, including recency, simultaneous versus sequential comparison, awareness of public opinion, the intensity of the stop-and-go traffic, and the fact that driving in the real-world is a goal directed activity. However without further research, which, if any, of these will eventually prove to be the reason is unclear. What is clear is that a comparison of the computer administered stated preference with virtual experience stated preference produces different results, even though both procedures strive to find the same answers in nominally identical sets of conditions. Because people experience the world subjectively, and make decisions based on those subjective experiences, future research should be aimed at better understanding the differences between these subjective methodologies.transportation, travel behavior, driving simulator, ramp meters
Holistic debugging - enabling instruction set simulation for software quality assurance
We present holistic debugging, a novel method for observing execution of complex and distributed software. It builds on an instruction set simulator, which provides reproducible experiments and non-intrusive probing of state in a distributed system. Instruction set simulators, however, only provide low-level information, so a holistic debugger contains a translation framework that maps this information to higher abstraction level observation tools, such as source code debuggers. We have created Nornir, a proof-of-concept holistic debugger, built on the simulator Simics. For each observed process in the simulated system, Nornir creates an abstraction translation stack, with virtual machine translators that map machine-level storage contents (e.g. physical memory, registers) provided by Simics, to application-level data (e.g. virtual memory contents) by parsing the data structures of operating systems and virtual machines. Nornir includes a modified version of the GNU debugger (GDB), which supports non-intrusive symbolic debugging of distributed applications. Nornir's main interface is a debugger shepherd, a programmable interface that controls multiple debuggers, and allows users to coherently inspect the entire state of heterogeneous, distributed applications. It provides a robust observation platform for construction of new observation tools
Development of UTHM’s Airship Virtual Simulator
Airship virtual simulator was developed by programming the solution of the airship equations of motion to Matlab GUI. This paper shows a case study done by applying the physical data of a designed airship called ‘UTHM’s Airship’ in the airship equations of motion for development of airship virtual simulator. In this study, the approximate and calculated stability modes of the designed airship were compared for validation purposes. The virtual simulator operates by selecting the desired control angle of elevator, rudder or vectored thrust as input and the response outputs are shown in motion of pitch, yaw or roll angle through a moving airship figure in the simulator. At the end of this paper, the virtual simulator had successfully helped interprets the response of the designed airship into an interesting and easy to understand visualization
Development of UTHM's Airship Virtual Simulator
Airship virtual simulator was developed by programming the solution of the airship equations of motion to Matlab GUI. This paper shows a case study done by applying the physical data of a designed airship called ‘UTHM’s Airship’ in the airship equations of motion for development of airship virtual simulator. In this study, the approximate and calculated stability modes of the designed airship were compared for validation purposes. The virtual simulator operates by selecting the desired control angle of elevator, rudder or vectored thrust as input and the response outputs are shown in motion of pitch, yaw or roll angle through a moving airship figure in the simulator. At the end of this paper, the virtual simulator had successfully helped interprets the response of the designed airship into an interesting and easy to understand visualization
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