Search results for "Computer-assisted"
showing 10 items of 1186 documents
Indications for Computer-Assisted Surgery in Otorhinolaryngology
1998
Indications for the use of computer-assisted surgery (CAS) in otorhinolaryngology can be grouped into several domains including the following: difficult cases involving the anterior, middle, and posterior skull base, especially the rhinobasis or laterobasis, and diseases of the petrous bone, the infratemporal fossa, the retromaxillar space, and the orbit; extended paranasal sinus surgery and revision cases with surgically altered anatomic landmarks; and use for educational purposes where CAS can provide better instruction in surgical anatomy by relating the surgical field to radiological sectional images. A new field for CAS is surgery of the inferior neck soft tissues or pathologic process…
Morse Description and Geometric Encoding of Digital Elevation Maps
2004
Two complementary geometric structures for the topographic representation of an image are developed in this work. The first one computes a description of the Morse-topological structure of the image, while the second one computes a simplified version of its drainage structure. The topographic significance of the Morse and drainage structures of digital elevation maps (DEMs) suggests that they can been used as the basis of an efficient encoding scheme. As an application, we combine this geometric representation with an interpolation algorithm and lossless data compression schemes to develop a compression scheme for DEMs. This algorithm achieves high compression while controlling the maximum …
Peer Group Mentoring Programmes in Finnish Higher Education––Mentors’ Perspectives
2014
Peer mentoring is one of the most important guidance practices for first-year students entering higher education and academic life. We are interested in mentors’ roles and apply the ideas of group counseling in order to increase the understanding of peer mentoring. Other aspects of guidance––content, methods, and collaboration––are approached on the basis of the holistic career guidance model. The data were gathered via an online questionnaire (n = 784) from 20 Finnish HE institutions. The results show that peer mentoring is a positive experience. The main emphasis is on the personal, psychosocial aspects of the student’s life. We identified four mentor types based on used activities. The e…
Automated detection of patient movement during a CBCT scan based on the projection data.
2015
Objectives To develop an automated procedure to detect patient motion on the projection images acquired during a cone beam computed tomography (CBCT) scan and to evaluate the method's feasibility on small real-world CBCT images in relation to visual assessment. Methods Based on optical flow theory, software was developed using the sequence of the projection images of a CBCT machine for automated detection of patient motion. Averaged acceleration vectors were used as measurement data and compared with visual assessment of the projection images displayed as video. Seventy-nine CBCT data sets (small field-of-view: 40 mm) from our patient database were selected in a sequential fashion and evalu…
Dental CBCT equipment and performance issues
2012
Dental cone beam computed tomography (CBCT), also known as digital volumetric tomography was developed in the late 1990s and is now increasingly available in clinical practice. It can provide high resolution cross-sectional images of teeth and the maxillofacial region with applications in all branches of dentistry. As a new imaging modality, there were no established suspension levels at a European level. A literature review, encompassing scientific, professional publications and existing national guidelines was performed in an attempt to develop a set of suspension levels for dental CBCT, using additional expert opinion from the members of the European Academy of dento-maxillo-facial radio…
Contrast perception in digitized panoramic radiographs compared with their film-based origin
2002
Abstract Objectives. We sought to compare the visual image quality of film-based and digitized panoramic radiographs through use of a hole-containing test wedge. Study Design. An aluminum wedge containing 100 cells, of which 90 were given shallow holes, was exposed in the film-based Orthophos CD panoramic unit. Two radiographs subjectively exhibiting optimum contrast were selected. Films were digitized with a charge-coupled device flatbed scanner at 300 dpi. Films and digitized images were rated cellwise by 2 similar groups of 50 observers each with respect to spot perception. Results. The mean sensitivity was 0.26 ± 0.09 for film and 0.20 ± 0.07 for digitized images (P =.000), with a prono…
Mammographic images segmentation based on chaotic map clustering algorithm
2013
Background: This work investigates the applicability of a novel clustering approach to the segmentation of mammographic digital images. The chaotic map clustering algorithm is used to group together similar subsets of image pixels resulting in a medically meaningful partition of the mammography. Methods: The image is divided into pixels subsets characterized by a set of conveniently chosen features and each of the corresponding points in the feature space is associated to a map. A mutual coupling strength between the maps depending on the associated distance between feature space points is subsequently introduced. On the system of maps, the simulated evolution through chaotic dynamics leads…
Collaborative business planning in initial vocational education and training
2015
There is a growing demand to enhance entrepreneurship. This study aims at producing knowledge that can assist teachers in designing and supporting collaborative learning of entrepreneurship in vocational education. A qualitative case study approach was adopted. The outcome of this study provides a better understanding of the factors that hinder and enable collaboration, as related to entrepreneurship education in initial vocational education and training. In practice, nine dimensions of descriptive factors that hindered the exercise and nine distinct descriptive factors that acted as enablers were identified. This study suggests that, although the script of the learning task creates the set…
What makes learning and understanding in virtual teams so difficult?
2004
The ideas presented in this article are especially challenged by critical questions raised by the other authors in this special issue. One of the core questions throughout the different studies is whether participants in distributed learning groups are able to successfully work on a common task and achieve a type of interaction that leads them to educationally relevant higher-level discussion and learning. This article discusses the central findings of these studies in light of the recent research on computer-supported collaborative learning. At the beginning of the article, typical problems and challenges related to learning in virtual teams are described. In the end of the discussion, som…
E-learning: Web-based education
2006
Purpose of review This review introduces state-of-the-art Web-based education and shows how the e-learning model can be applied to an anaesthesia department using Open Source solutions, as well as lifelong learning programs, which is happening in several European research projects. Recent findings The definition of the term e-learning is still a work in progress due to the fact that technologies are evolving every day and it is difficult to improve teaching methodologies or to adapt traditional methods to a new or already existing educational model. The European Community is funding several research projects to define the new common market place for tomorrow's educational system; this is le…