New target tracking and monitoring guidance laws for UAV

A pursuer UAV tracking and loitering around a target is the problem analyzed in this thesis. The UAV is assumed to be a fixed-wing vehicle and constant airspeed together with bounded lateral accelerations are the main constraints of the problem. Three different guidance laws are designed for ensuring a continuos overfly on the target. Different proofs are presented to demonstrate the stability properties of the laws. All the algorithms are tested on a 6DoF Pioneer software simulator. Classic control design methods have been adopted to develop autopilots for implementig the simulation platform used for testing the guidance laws.

Post-mortem tissue sampling using computed tomography guidance

PURPOSE: Currently, in forensic medicine cross-sectional imaging gains recognition and a wide use as a non-invasive examination approach. Today, computed tomography (CT) or magnetic resonance imaging that are available for patients are unable to provide tissue information on the cellular level in a non-invasive manner and also diatom detection, DNA, bacteriological, chemical toxicological and other specific tissue analyses are impossible using radiology. We hypothesised that post-mortem minimally invasive tissue sampling using needle biopsies under CT guidance might significantly enhance the potential of virtual autopsy. The purpose of this study was to test the use of a clinically approved biopsy needle for minimally invasive post-mortem sampling of tissue specimens under CT guidance. MATERIAL AND METHODS: ACN III biopsy core needles 14 gauge x 160 mm with automatic pistol device were used on three bodies dedicated to research from the local anatomical institute. Tissue probes from the brain, heart, lung, liver, spleen, kidney and muscle tissue were obtained under CT fluoroscopy. RESULTS: CT fluoroscopy enabled accurate placement of the needle within the organs and tissues. The needles allowed for sampling of tissue probes with a mean width of 1.7 mm (range 1.2-2 mm) and the maximal length of 20 mm at all locations. The obtained tissue specimens were of sufficient size and adequate quality for histological analysis. CONCLUSION: Our results indicate that, similar to the clinical experience but in many more organs, the tissue specimens obtained using the clinically approved biopsy needle are of a sufficient size and adequate quality for a histological examination. We suggest that post-mortem biopsy using the ACN III needle under CT guidance may become a reliable method for targeted sampling of tissue probes of the body.

[Rehabilitation of an abraded occlusion with Procera-ZrO2 all-ceramic crowns. A case report]

The rehabilitation of a patient with advanced tooth wear by means of Procera ZrO2 ceramic crowns is described. A healthy, 60 year old patient complained about front teeth esthetics and impaired function due to reduced tooth height. He was aware of bruxism and wished full mouth rehabilitation. The clinical examination showed that tooth wear was generalized, but most teeth could be maintained in both jaws. A staged procedure was planned, starting with a splint therapy and a provisional fixed prosthesis to reestablish correct vertical dimension of occlusion (VDO) and stable occlusal contacts. The new ZrO2 material with the Procera technique was chosen to restore all teeth in both jaws, except the mandible front teeth. In the second treatment phase, crown lengthening of the maxillary front teeth was performed and one implant placed to replace a maxillary premolar. After final tooth preparation, impression taking and bite registration the ZrO2 crown-copings were scanned, processed and completed by veneering. A flat occlusal scheme with stable front teeth guidance was established. The advantage of the presented treatment is the esthetic result in combination with a material of high mechanical and biological quality.

Projector-based augmented reality for intuitive intraoperative guidance in image-guided 3D interstitial brachytherapy

PURPOSE: The aim of this study is to implement augmented reality in real-time image-guided interstitial brachytherapy to allow an intuitive real-time intraoperative orientation. METHODS AND MATERIALS: The developed system consists of a common video projector, two high-resolution charge coupled device cameras, and an off-the-shelf notebook. The projector was used as a scanning device by projecting coded-light patterns to register the patient and superimpose the operating field with planning data and additional information in arbitrary colors. Subsequent movements of the nonfixed patient were detected by means of stereoscopically tracking passive markers attached to the patient. RESULTS: In a first clinical study, we evaluated the whole process chain from image acquisition to data projection and determined overall accuracy with 10 patients undergoing implantation. The described method enabled the surgeon to visualize planning data on top of any preoperatively segmented and triangulated surface (skin) with direct line of sight during the operation. Furthermore, the tracking system allowed dynamic adjustment of the data to the patient's current position and therefore eliminated the need for rigid fixation. Because of soft-part displacement, we obtained an average deviation of 1.1 mm by moving the patient, whereas changing the projector's position resulted in an average deviation of 0.9 mm. Mean deviation of all needles of an implant was 1.4 mm (range, 0.3-2.7 mm). CONCLUSIONS: The developed low-cost augmented-reality system proved to be accurate and feasible in interstitial brachytherapy. The system meets clinical demands and enables intuitive real-time intraoperative orientation and monitoring of needle implantation.

Integration of merged delayed-enhanced magnetic resonance imaging and multidetector computed tomography for the guidance of ventricular tachycardia ablation: a pilot study

BACKGROUND Delayed enhancement (DE) MRI can assess the fibrotic substrate of scar-related VT. MDCT has the advantage of inframillimetric spatial resolution and better 3D reconstructions. We sought to evaluate the feasibility and usefulness of integrating merged MDCT/MRI data in 3D-mapping systems for structure-function assessment and multimodal guidance of VT mapping and ablation. METHODS Nine patients, including 3 ischemic cardiomyopathy (ICM), 3 nonischemic cardiomyopathy (NICM), 2 myocarditis, and 1 redo procedure for idiopathic VT, underwent MRI and MDCT before VT ablation. Merged MRI/MDCT data were integrated in 3D-mapping systems and registered to high-density endocardial and epicardial maps. Low-voltage areas (<1.5 mV) and local abnormal ventricular activities (LAVA) during sinus rhythm were correlated to DE at MRI, and wall-thinning (WT) at MDCT. RESULTS Endocardium and epicardium were mapped with 391 ± 388 and 1098 ± 734 points per map, respectively. Registration of MDCT allowed visualization of coronary arteries during epicardial mapping/ablation. In the idiopathic patient, integration of MRI data identified previously ablated regions. In ICM patients, both DE at MRI and WT at MDCT matched areas of low voltage (overlap 94 ± 6% and 79 ± 5%, respectively). In NICM patients, wall-thinning areas matched areas of low voltage (overlap 63 ± 21%). In patients with myocarditis, subepicardial DE matched areas of epicardial low voltage (overlap 92 ± 12%). A total number of 266 LAVA sites were found in 7/9 patients. All LAVA sites were associated to structural substrate at imaging (90% inside, 100% within 18 mm). CONCLUSION The integration of merged MDCT and DEMRI data is feasible and allows combining substrate assessment with high-spatial resolution to better define structure-function relationship in scar-related VT.

Guidance of treatment decisions in risk-adapted primary radiotherapy for prostate cancer using multiparametric magnetic resonance imaging: a single center experience.

BACKGROUND Magnetic resonance imaging (MRI) of the prostate is considered to be the most precise noninvasive staging modality for localized prostate cancer. Multiparametric MRI (mpMRI) dynamic sequences have recently been shown to further increase the accuracy of staging relative to morphological imaging alone. Correct radiological staging, particularly the detection of extraprostatic disease extension, is of paramount importance for target volume definition and dose prescription in highly-conformal curative radiotherapy (RT); in addition, it may affect the risk-adapted duration of additional antihormonal therapy. The purpose of our study was to analyze the impact of mpMRI-based tumor staging in patients undergoing primary RT for prostate cancer. METHODS A total of 122 patients admitted for primary RT for prostate cancer were retrospectively analyzed regarding initial clinical and computed tomography-based staging in comparison with mpMRI staging. Both tumor stage shifts and overall risk group shifts, including prostate-specific antigen (PSA) level and the Gleason score, were assessed. Potential risk factors for upstaging were tested in a multivariate analysis. Finally, the impact of mpMRI-based staging shift on prostate RT and antihormonal therapy was evaluated. RESULTS Overall, tumor stage shift occurred in 55.7% of patients after mpMRI. Upstaging was most prominent in patients showing high-risk serum PSA levels (73%), but was also substantial in patients presenting with low-risk PSA levels (50%) and low-risk Gleason scores (45.2%). Risk group changes occurred in 28.7% of the patients with consequent treatment adaptations regarding target volume delineation and duration of androgen deprivation therapy. High PSA levels were found to be a significant risk factor for tumor upstaging and newly diagnosed seminal vesicle infiltration assessed using mpMRI. CONCLUSIONS Our findings suggest that mpMRI of the prostate leads to substantial tumor upstaging, and can considerably affect treatment decisions in all patient groups undergoing risk-adapted curative RT for prostate cancer.

Feasibility of stereotactic MRI-based image guidance for the treatment of vascular malformations: a phantom study.

PURPOSE Treatment of vascular malformations requires the placement of a needle within vessels which may be as small as 1 mm, with the current state of the art relying exclusively on two-dimensional fluoroscopy images for guidance. We hypothesize that the combination of stereotactic image guidance with existing targeting methods will result in faster and more reproducible needle placements, as well as reduced radiationexposure, when compared to standard methods based on fluoroscopy alone. METHODS The proposed navigation approach was evaluated in a phantom experiment designed to allow direct comparison with the conventional method. An anatomical phantom of the left forearm was constructed, including an independent control mechanism to indicate the attainment of the target position. Three interventionalists (one inexperienced, two of them frequently practice the conventional fluoroscopic technique) performed 45 targeting attempts utilizing the combined and 45 targeting attempts utilizing the standard approaches. RESULTS In all 45 attempts, the users were able to reach the target when utilizing the combined approach. In two cases, targeting was stopped after 15 min without reaching the target when utilizing only the C-arm. The inexperienced user was faster when utilizing the combined approach and applied significantly less radiation than when utilizing the conventional approach. Conversely, both experienced users were faster when using the conventional approach, in one case significantly so, with no significant difference in radiation dose when compared to the combined approach. CONCLUSIONS This work presents an initial evaluation of a combined navigation fluoroscopy targeting technique in a phantom study. The results suggest that, especially for inexperienced interventionalists, navigation may help to reduce the time and the radiation dose. Future work will focus on the improvement and clinical evaluation of the proposed method.

Practice advisory: interim guidance for care of obstetric patients during a zika virus outbreak

Zika during pregnancy has been associated with birth defects, specifically significant microcephaly. Transmission of Zika to the fetus has been documented in all trimesters; Zika virus RNA has been detected in fetal tissue from early missed abortions, amniotic fluid, term neonates and the placenta. However, much is not yet known about Zika virus in pregnancy. Uncertainties include the incidence of Zika virus infection among pregnant women in areas of Zika virus transmission, the rate of vertical transmission and the rate with which infected fetuses manifest complications such as microcephaly or demise. The absence of this important information makes management and decision making in the setting of potential Zika virus exposure (i.e. travel to endemic areas) or maternal infection, difficult. Currently, there is no vaccine or treatment for this infection.

The XXI century guidance and its social responsibility

El presente trabajo tiene como finalidad considerar la orientación del siglo XXI en Venezuela como una disciplina con un alto compromiso social. Como programa, debe, hoy día, redefinirse con el objeto de impulsar propuestas conducentes a la inclusión de todas aquellas personas, que tradicionalmente han sido excluidas por su raza, etnia, género y/o discapacidad física y que como praxis social esté dirigida a la facilitación de los procesos de desarrollo humano en las dimensiones del Ser, Convivir, Servir, Conocer y Hacer, en el contexto personal, familiar y comunitario a lo largo del continuo del ciclo vital. L as competencias adquiridas a través de los procesos de orientación, son determinantes para proporcionar los medios a las ciudadanas y los ciudadanos para gestionar su propio desarrollo y el de su comunidad Se plantea la necesidad de un cambio de paradigma que deje atrás la clásica postura de un orientador que ayuda al orientado, desde el que conoce, el que tiene experiencia. Se sugiere más bien una relación de orientación intersubjetiva. Por otra parte, se habla de la necesidad de fortalecer el capital social de los espacios que contextualizan el proceso orientador. Se explican además, los alcances del Sistema Nacional de Orientación.

Theoretical frames for the new tasks in career guidance and counseling

Personal and career development interventions aim to help people find answers to personal and career development issues that stem from the societal context in which they live. Societal definitions of these career issues have a double consequence. On the one hand, these issues differ from one culture to another; and, on the other, they evolve along with the contexts in which they are expressed. Implementation of rigorous career development interventions requires, first, a scientific reconstruction of these societal issues and, second, a clear definition of these interventions' goals and ends. Our current view of the societal issues relating to personal and career development interventions may be phrased thus--"How can we help individuals direct their lives, in the (human) society where they interact?" It may be turned into the following scientific question: "What are the factors and processes of life-long self-construction?" An articulation of three major propositions (sociological, cognitive and dynamic) seems to be needed to answer this question. Such a theoretical frame does not allow for a definition of personal and career development interventions ends. In the world of today, the adoption by everyone of a personal ethic of responsibility towards all life on Earth (H. Jonas) could well be a fundamental end to these interventions.

Career Guidance: Challenges for the New Century under an International Perspective

This paper is dedicated to key issues of the actual challenges in all societies regardless their developmental level and how the international guidance community is coping with these challenges. It deals with the importance of guidance in a changing society, quality assurance, access to services and qualification of guidance practitioners under an international perspective.

The increasing role of career guidance at the turn of the centuries

At the beginning this paper sketches trends of the rapid changes of nearly all life issues, especially in society, work behaviours, labour environment and demands for adjustment under new social values. As main factors which influence worldwide the economic development and the labour market are elaborated the globalization and liberalization process and the labour market aspects of feminization, ageing labour force, migration, unemployment as a global phenomenon and general changes in labour demand by occupations and skill level. A well-developed and highly qualified career guidance service is seen as one of the most effective instruments in solving these problems which are raised by the described developements. The personal and psychological effects of uncertainty and dislocation of people and the new requirements of the expected qualification standard make career guidance an important cornerstone to cope with these social aspects. Thus, the nature and structure of guidance and counselling are described under the new challenges. The international co-operation in the guidance sector has accompanied this process in delivering two important documents. The Mission Statement and the Ethical Standards of IAEVG, adopted by the General Assembly of IAEVG in 1995, show in what direction guidance services have to be developed.

The XXI century guidance and its social responsibility

El presente trabajo tiene como finalidad considerar la orientación del siglo XXI en Venezuela como una disciplina con un alto compromiso social. Como programa, debe, hoy día, redefinirse con el objeto de impulsar propuestas conducentes a la inclusión de todas aquellas personas, que tradicionalmente han sido excluidas por su raza, etnia, género y/o discapacidad física y que como praxis social esté dirigida a la facilitación de los procesos de desarrollo humano en las dimensiones del Ser, Convivir, Servir, Conocer y Hacer, en el contexto personal, familiar y comunitario a lo largo del continuo del ciclo vital. L as competencias adquiridas a través de los procesos de orientación, son determinantes para proporcionar los medios a las ciudadanas y los ciudadanos para gestionar su propio desarrollo y el de su comunidad Se plantea la necesidad de un cambio de paradigma que deje atrás la clásica postura de un orientador que ayuda al orientado, desde el que conoce, el que tiene experiencia. Se sugiere más bien una relación de orientación intersubjetiva. Por otra parte, se habla de la necesidad de fortalecer el capital social de los espacios que contextualizan el proceso orientador. Se explican además, los alcances del Sistema Nacional de Orientación.

Theoretical frames for the new tasks in career guidance and counseling

Personal and career development interventions aim to help people find answers to personal and career development issues that stem from the societal context in which they live. Societal definitions of these career issues have a double consequence. On the one hand, these issues differ from one culture to another; and, on the other, they evolve along with the contexts in which they are expressed. Implementation of rigorous career development interventions requires, first, a scientific reconstruction of these societal issues and, second, a clear definition of these interventions' goals and ends. Our current view of the societal issues relating to personal and career development interventions may be phrased thus--"How can we help individuals direct their lives, in the (human) society where they interact?" It may be turned into the following scientific question: "What are the factors and processes of life-long self-construction?" An articulation of three major propositions (sociological, cognitive and dynamic) seems to be needed to answer this question. Such a theoretical frame does not allow for a definition of personal and career development interventions ends. In the world of today, the adoption by everyone of a personal ethic of responsibility towards all life on Earth (H. Jonas) could well be a fundamental end to these interventions.

Career Guidance: Challenges for the New Century under an International Perspective

This paper is dedicated to key issues of the actual challenges in all societies regardless their developmental level and how the international guidance community is coping with these challenges. It deals with the importance of guidance in a changing society, quality assurance, access to services and qualification of guidance practitioners under an international perspective.