MatchPoint:Spontaneous Spatial Coupling of Body Movement for Touchless Pointing

Pointing is a fundamental interaction technique where user movement is translated to spatial input on a display. Conventionally, this is based on a rigid configuration of a display coupled with a pointing device that determines the types of movement that can be sensed, and the specific ways users can affect pointer input. Spontaneous spatial coupling is a novel input technique that instead allows any body movement, or movement of tangible objects, to be appropriated for touchless pointing on an ad hoc basis. Pointer acquisition is facilitated by the display presenting graphical objects in motion, to which users can synchronise to define a temporary spatial coupling with the body part or tangible object they used in the process. The technique can be deployed using minimal hardware, as demonstrated by MatchPoint, a generic computer vision-based implementation of the technique that requires only a webcam. We explore the design space of spontaneous spatial coupling, demonstrate the versatility of the technique with application examples, and evaluate MatchPoint performance using a multi-directional pointing task

AR open surgery training for total hip arthroplasty

Background: The competency and skill development of aspiring surgeons heavily depend on surgical training. Traditionally, open surgery training has relied on cadavers, enabling trainees to actively participate in tutor-guided and evaluated interventions, which are crucial aspects of their education. Nonetheless, this approach places additional burdens and risks on patients, along with considerable time and financial constraints. Objective: Our goal is to develop an all-encompassing Learning Platform designed to offer standardized training modules for laparoscopy, arthroscopy, and open surgery. A pivotal element of this endeavor involves integrating a quantitative and systematic approach to assess surgical skills objectively, utilizing predefined criteria. This task would be challenging without the assistance of digital technologies. The introduction of this groundbreaking training method represents a remarkable leap forward in the field. The implementation of the learning platform encompasses three distinct sub-projects.AR Based Training: Our main objective is to create an AR-based simulator for open orthopedic surgery training, specifically focusing on Total Hip Arthroplasty. This simulator represents a significant advancement over conventional cadaver-based training as it integrates adaptive AR guidance and AI techniques. By harnessing the power of intuitive AR instructions and leveraging AI-driven analysis of human activity and behavior, our aim is to optimize the usability of surgical training simulators. Ultimately, this will reduce the strain on patients and minimize the requirement for constant instructor and technical support during surgical education

Skin Barrier Development Depends on CGI-58 Protein Expression during Late-Stage Keratinocyte Differentiation

Adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58) are limiting in cellular triglyceride catabolism. Although ATGL deficiency is compatible with normal skin development, mice globally lacking CGI-58 die postnatally and exhibit a severe epidermal permeability barrier defect, which may originate from epidermal and/or peripheral changes in lipid and energy metabolism. Here, we show that epidermis-specific disruption of CGI-58 is sufficient to provoke a defect in the formation of a functional corneocyte lipid envelope linked to impaired ω-O-acylceramide synthesis. As a result, epidermis-specific CGI-58-deficient mice show severe skin dysfunction, arguing for a tissue autonomous cause of disease development. Defective skin permeability barrier formation in global CGI-58-deficient mice could be reversed via transgenic restoration of CGI-58 expression in differentiated but not basal keratinocytes suggesting that CGI-58 is essential for lipid metabolism in suprabasal epidermal layers. The compatibility of ATGL deficiency with normal epidermal function indicated that CGI-58 may stimulate an epidermal triglyceride lipase beyond ATGL required for the adequate provision of fatty acids as a substrate for ω-O-acylceramide synthesis. Pharmacological inhibition of ATGL enzyme activity similarly reduced triglyceride-hydrolytic activities in wild-type and CGI-58 overexpressing epidermis implicating that CGI-58 participates in ω-O-acylceramide biogenesis independent of its role as a coactivator of epidermal triglyceride catabolism

Information Indices with High Discriminative Power for Graphs

In this paper, we evaluate the uniqueness of several information-theoretic measures for graphs based on so-called information functionals and compare the results with other information indices and non-information-theoretic measures such as the well-known Balaban index. We show that, by employing an information functional based on degree-degree associations, the resulting information index outperforms the Balaban index tremendously. These results have been obtained by using nearly 12 million exhaustively generated, non-isomorphic and unweighted graphs. Also, we obtain deeper insights on these and other topological descriptors when exploring their uniqueness by using exhaustively generated sets of alkane trees representing connected and acyclic graphs in which the degree of a vertex is at most four

Fast Marker Based C-Arm Pose Estimation

Abstract. To estimate the pose of a C-Arm during interventions therapy we have developed a small sized X-Ray Target including a special set of beads with known locations in 3D space. Since the patient needs to remain in the X-Ray path for all feasible poses of the C-Arm during the intervention, we cannot construct a single marker which is entirely visible in all images. Therefore finding 2D-3D point correspondences is a non-trivial task. The marker pattern has to be chosen in a way such that its projection onto the image plane is unique in a minimal-sized window for all relevant poses of the C-Arm. We use a two dimensional adaption of a linear feedback shift register (LFSR) to generate a twodimensional pattern with unique sub-patterns in a certain window range. Thereby uniqueness is not achieved by placing unique 2D sub patterns side by side but by the code property itself. The code is designed in a way that any sub window of a minimal size guarantees uniqueness and that even occlusions from medical instruments can be handled. Experiments showed that we were able to estimate the C-Arm’s pose from a single image within one second with a precision below one millimeter and one degree.

Structural discrimination of networks by using distance, degree and eigenvalue-based measures.

In chemistry and computational biology, structural graph descriptors have been proven essential for characterizing the structure of chemical and biological networks. It has also been demonstrated that they are useful to derive empirical models for structure-oriented drug design. However, from a more general (complex network-oriented) point of view, investigating mathematical properties of structural descriptors, such as their uniqueness and structural interpretation, is also important for an in-depth understanding of the underlying methods. In this paper, we emphasize the evaluation of the uniqueness of distance, degree and eigenvalue-based measures. Among these are measures that have been recently investigated extensively. We report numerical results using chemical and exhaustively generated graphs and also investigate correlations between the measures

Value distribution for .

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Correlation network inferred from .

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