110 research outputs found
A Map of the Nanoworld: Sizing up the Science, Politics, and Business of the Infinitesimal
Mapping out the eight main nodes of nanotechnology discourse that have
emerged in the past decade, we explore how various scientific, social, and
ethical islands of discussion have developed, been recognized, and are being
continually renegotiated. We do so by (1) identifying the ways in which
scientists, policy makers, entrepreneurs, educators, and environmental groups
have drawn boundaries on issues relating to nanotechnology; (2) describing
concisely the perspectives from which these boundaries are drawn; and (3)
exploring how boundaries on nanotechnology are marked and negotiated by various
nodes of nanotechnology discourse.Comment: 25 page
EVA: Laparoscopic instrument tracking based on endoscopic video analysis for psychomotor skills assessment
INTRODUCTION: The EVA (Endoscopic Video Analysis) tracking system a new tracking system for extracting motions of laparoscopic instruments based on non-obtrusive video tracking was developed. The feasibility of using EVA in laparoscopic settings has been tested in a box trainer setup.
METHODS: EVA makes use of an algorithm that employs information of the laparoscopic instrument's shaft edges in the image, the instrument's insertion point, and the camera's optical centre to track the 3D position of the instrument tip. A validation study of EVA comprised a comparison of the measurements achieved with EVA and the TrEndo tracking system. To this end, 42 participants (16 novices, 22 residents, and 4 experts) were asked to perform a peg transfer task in a box trainer. Ten motion-based metrics were used to assess their performance.
RESULTS: Construct validation of the EVA has been obtained for seven motion-based metrics. Concurrent validation revealed that there is a strong correlation between the results obtained by EVA and the TrEndo for metrics such as path length (p=0,97), average speed (p=0,94) or economy of volume (p=0,85), proving the viability of EVA.
CONCLUSIONS: EVA has been successfully used in the training setup showing potential of endoscopic video analysis to assess laparoscopic psychomotor skills. The results encourage further implementation of video tracking in training setups and in image guided surgery
The value of haptic feedback in conventional and robot-assisted minimal invasive surgery and virtual reality training: a current review
BACKGROUND: Virtual reality (VR) as surgical training tool has become a state-of-the-art technique in training and teaching skills for minimally invasive surgery (MIS). Although intuitively appealing, the true benefits of haptic (VR training) platforms are unknown. Many questions about haptic feedback in the different areas of surgical skills (training) need to be answered before adding costly haptic feedback in VR simulation for MIS training. This study was designed to review the current status and value of haptic feedback in conventional and robot-assisted MIS and training by using virtual reality simulation. METHODS: A systematic review of the literature was undertaken using PubMed and MEDLINE. The following search terms were used: Haptic feedback OR Haptics OR Force feedback AND/OR Minimal Invasive Surgery AND/OR Minimal Access Surgery AND/OR Robotics AND/OR Robotic Surgery AND/OR Endoscopic Surgery AND/OR Virtual Reality AND/OR Simulation OR Surgical Training/Education. RESULTS: The results were assessed according to level of evidence as reflected by the Oxford Centre of Evidence-based Medicine Levels of Evidence. CONCLUSIONS: In the current literature, no firm consensus exists on the importance of haptic feedback in performing minimally invasive surgery. Although the majority of the results show positive assessment of the benefits of force feedback, results are ambivalent and not unanimous on the subject. Benefits are least disputed when related to surgery using robotics, because there is no haptic feedback in currently used robotics. The addition of haptics is believed to reduce surgical errors resulting from a lack of it, especially in knot tying. Little research has been performed in the area of robot-assisted endoscopic surgical training, but results seem promising. Concerning VR training, results indicate that haptic feedback is important during the early phase of psychomotor skill acquisitio
Severe traumatic injury during long duration spaceflight: Light years beyond ATLS
Traumatic injury strikes unexpectedly among the healthiest members of the human population, and has been an inevitable companion of exploration throughout history. In space flight beyond the Earth's orbit, NASA considers trauma to be the highest level of concern regarding the probable incidence versus impact on mission and health. Because of limited resources, medical care will have to focus on the conditions most likely to occur, as well as those with the most significant impact on the crew and mission. Although the relative risk of disabling injuries is significantly higher than traumatic deaths on earth, either issue would have catastrophic implications during space flight. As a result this review focuses on serious life-threatening injuries during space flight as determined by a NASA consensus conference attended by experts in all aspects of injury and space flight
Construct validity of the LapSim: Can the LapSim virtual reality simulator distinguish between novices and experts?
Appearance Modeling of Living Human Tissues
This is the peer reviewed version of the following article: Nunes, A.L.P., Maciel, A., Meyer, G.W., John, N.W., Baranoski, G.V.G., & Walter, M. (2019). Appearance Modeling of Living Human Tissues, Computer Graphics Forum, which has been published in final form at https://doi.org/10.1111/cgf.13604. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingThe visual fidelity of realistic renderings in Computer Graphics depends fundamentally upon how we model the appearance of
objects resulting from the interaction between light and matter reaching the eye. In this paper, we survey the research addressing
appearance modeling of living human tissue. Among the many classes of natural materials already researched in Computer
Graphics, living human tissues such as blood and skin have recently seen an increase in attention from graphics research. There
is already an incipient but substantial body of literature on this topic, but we also lack a structured review as presented here.
We introduce a classification for the approaches using the four types of human tissues as classifiers. We show a growing trend
of solutions that use first principles from Physics and Biology as fundamental knowledge upon which the models are built. The
organic quality of visual results provided by these Biophysical approaches is mainly determined by the optical properties of
biophysical components interacting with light. Beyond just picture making, these models can be used in predictive simulations,
with the potential for impact in many other areas
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