Non-invasive surface registration methods have been developed to register and track breathing motions in a patient’s abdomen and thorax. We evaluated several different registration methods, including marker tracking using a stereo camera, chessboard image projection, and abdominal point clouds. Our point cloud approach was based on a time-of-flight (ToF) sensor that tracked the abdominal surface. We tested different respiratory phases using additional markers as landmarks for the extension of the non-rigid Iterative Closest Point (ICP) algorithm to improve the matching of irregular meshes. Four variants for retrieving the correspondence data were implemented and compared. Our evaluation involved 9 healthy individuals (3 females and 6 males) with point clouds captured in opposite breathing phases (i.e., inhalation and exhalation). We measured three factors: surface distance, correspondence distance, and marker error. To evaluate different methods for computing the correspondence measurements, we defined the number of correspondences for every target point and the average correspondence assignment error of the points nearest the markers.

Nowadays, the math learning is an important step in developing professional carriers in technical and economic sciences. Increasing the number of e-learning tools used in universities courses can reduce the potential barrier of access to mathematical knowledge, but most of them are not accessible for impaired students. Moreover, classical printed math books include little explicit instructional information about structural information interpretations. Taking into account these barriers the article presents the developed method used for creating interactive steps of decomposed math's exercise solution and alternative description of math formulas accessible for the blind. The elements of proposed methodology: generation of state machine, design and presentation of transition conditions, generating the presentation layer and a typical usage by a blind user are presented. A set of rules for describing mathematical formulas were proposed after consultation with mathematicians and teachers of blind people. The application was developed as web application. The graphical interface of presented application was designed using PHP and JavaScript technologies. The collection of prepared exercises include about 240 prepared exercises from different areas of mathematics Multimed Tools Appl (2018) and 60 selected exercises including alternative description layer. About 1000 students and about 40 impaired students, from 6 faculties of the university use this platform during math courses for both self and class learning. The defined rules were used to read aloud mathematical formulas to the visually impaired people with a different level of mathematical knowledge. The results confirmed good understanding of mathematical formulas by using prepared alternative description.

BackgroundDiagnosing and treating anorexia nervosa is an important challenge for modern psychiatry. Taking into account a connection between the mental state of a person and the characteristics of their language, this paper presents developed and tested method for analyzing the written statements of patients with anorexia nervosa and healthy individuals, including the identification of keywords.MethodsDue to the short nature of the texts, which is related to the difficulty of expressing oneself about one’s body when suffering from anorexia, the bag of words approach was used for documents’ information representation. The document is represented as a vector, where its various elements indicate the number of individual words. Then, a rule-based model was created, where as a collection of rules, dictionary files were used corresponding to three groups of positive, negative and neutral sounds for each subcategory. Next in the analyzed texts were searched and counted keywords. Based on the keywords found, each of the documents was categorized into one of the groups in every subcategory.ResultsIt is possible to indicate a set of characteristics sentiment for every person. Additionally, the results of specific patient could be analyzed in six specific subcategories: self-esteem, acceptance of the assessment of the environment, emotions, autoimmune, functioning of the body and body image.ConclusionsThe described analysis indicates the existence of a relationship between the mental state of the author’s textual health and the vocabulary he or she uses. It is possible to indicate a set of characteristic sentiment terms specific to a given group of people. Their presence is related to the author’s mental state and their body image. It could help focus on specific topics during therapy.

In this study an approach to open architecture computer-aided diagnosis (CAD) is presented. The traditional goal of a CAD system, to assist the physicians in performing the diagnosis and treatment, has been extended. The platform also supports the system designer in developing a new CAD workflow by implementing general-purpose modules as well as problem-dependent procedures. A new CAD may require new procedures to be added, yet some of the already implemented functions can be employed. The CAD environment is subjected to the developmental process of three systems: the multiple sclerosis CAD, the lung nodule CAD and the pneumothorax CAD. Modules and procedures are briefly described and the CAD systems are evaluated. Results obtained during the CAD evaluation show prospective flexibility of the infrastructure. The trade-offs, well known to CAD designers, can easily be handled by the operators in a user-friendly manner by choosing various workflow paths.

BackgroundLiver segmentation in computed tomography is required in many clinical applications. The segmentation methods used can be classified according to a number of criteria. One important criterion for method selection is the shape representation of the segmented organ. The aim of the work is automatic liver segmentation using general purpose shape modeling methods.MethodsAs part of the research, methods based on shape information at various levels of advancement were used. The single atlas based segmentation method was used as the simplest shape-based method. This method is derived from a single atlas using the deformable free-form deformation of the control point curves. Subsequently, the classic and modified Active Shape Model (ASM) was used, using medium body shape models. As the most advanced and main method generalized statistical shape models, Gaussian Process Morphable Models was used, which are based on multi-dimensional Gaussian distributions of the shape deformation field.ResultsMutual information and sum os square distance were used as similarity measures. The poorest results were obtained for the single atlas method. For the ASM method in 10 analyzed cases for seven test images, the Dice coefficient was above 55, of which for three of them the coefficient was over 70, which placed the method in second place. The best results were obtained for the method of generalized statistical distribution of the deformation field. The DICE coefficient for this method was 88.5ConclusionsThis value of 88.5 Dice coefficient can be explained by the use of general-purpose shape modeling methods with a large variance of the shape of the modeled object—the liver and limitations on the size of our training data set, which was limited to 10 cases. The obtained results in presented fully automatic method are comparable with dedicated methods for liver segmentation. In addition, the deforamtion features of the model can be modeled mathematically by using various kernel functions, which allows to segment the liver on a comparable level using a smaller learning set.

BackgroundThe geometry of the vessels is easy to assess in novel 3D studies. It has significant influence on flow patterns and this way the evolution of vascular pathologies such as aneurysms and atherosclerosis. It is essential to develop robust system for vascular anatomy measurement and digital description allowing for assessment of big numbers of vessels.MethodsA semiautomatic, robust, integrated method for vascular anatomy measurements and mathematical description are presented. Bezier splines of 6th degree and continuity of C3 was proposed and distribution of control points was dependent on local radius. Due to main interest of our institution, the system was primarily used for the assessment of the geometry of the intracranial arteries, especially the first Medial Cerebral Artery division.Results1359 synthetic figures were generated: 381 torus and 978 spirals. Experimental verification of the proposed methodology was conducted on 400 Middle Cerebral Artery divisions.ConclusionsIn difference to other described solution all proposed methodology steps were integrated allows analysis of variability of geometrical parameters among big number of Medial Cerebral Artery bifurcations using single application. This allows for determination of significant trends in the parameters variability with age and in contrary almost no differences between men and women.

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The paper presents a practical approach to measuring liver motion, both respiratory and laparoscopic, with a tool guided in the operating room. The presented method is based on standard operating room equipment, i.e. rigid laparoscopic cameras and a single incision laparoscopic surgery trocar. The triangulation algorithm is used and stereo correspondence points are marked manually by two independent experts. To calibrate the cameras two perpendicular chessboards, a pinhole camera model and a Tsai algorithm are used. The data set consists of twelve real liver surgery video sequences: ten open surgery and two laparoscopic, gathered from different patients. The setup equipment and methodology are presented. The proposed evaluation method based on both calibration points of the chessboard reconstruction and measurements made by the Polaris Vicra tracking system are used as a reference system. In the analysis stage we focused on two specific goals, measuring respiration and laparoscopic tool guided liver motions. We have presented separate examples for left and right liver lobes. It is possible to reconstruct liver motion using the SILS trocar. Our approach was made without additional position or movement sensors. Diffusion of cameras and laser for distance measurement seems to be less practical for in vivo laparoscopic data, but we do not exclude exploring such sensors in further research.