957 resultados para Angular scan


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We present a case of central nervous system (CNS) infection by a member of the Penicillium genera in a HIV-negative man in Brazil. The patient was admitted complaining of loss of visual fields and speech disturbances. CT scan revealed multiple brain abscesses. Stereothacic biopsies revealed fungal infection and amphotericin B treatment begun with initial improvement. The patient died few days later as a consequence of massive gastrointestinal bleeding due to ruptured esophageal varices. The necropsy and final microbiologic analyses disclosed infection by Penicillium sp. There are thousands of fungal species of the Penicillium genera. Systemic penicilliosis is caused by the P. marneffei and was formerly a rare disease, but now is one of the most common opportunistic infection of AIDS patients in Southeast Asia. The clinical presentation usually involves the respiratory system and the skin, besides general symptoms like fever and weight loss. Penicillium spp infection caused by species other than P. marneffei normally cause only superficial or allergic disease but rare cases of invasive disease do occur. We report the fourth case of Penicillium spp CNS infection.

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OBJECTIVE: Venous aneurysms of the lower limbs are rare. When they involve the deep venous system, they can be associated with deep venous thrombosis and pulmonary embolism. The authors report the case of a 63-year-old women evaluated by duplex imaging and venography, in the context of a pulmonary embolism, and detected bilateral large aneurysms of the femoral veins (5 cm in the right femoral vein and 4 cm in the left femoral vein). The aneurysms were located at the bifurcation of the common femoral vein with the superficial and profound veins. METHOD: The right aneurysm was partially thrombosed. The patient was asymptomatic in the lower-limb extremities. After a period of anticoagulation, the authors proceeded to surgically excise the right aneurysm and replaced the venous system using a polytetrafluoroethylene (PTFE) graft with the construction of an a-v fistula. RESULT: The patient had no complications in the postoperative period and her 8-month follow-up examination revealed no symptoms, not even leg edema. The duplex scan showed patency of the graft. She continued with oral anticoagulation. The histologic examination revealed an eosinophilic inflammatory reaction of the vein wall, compatible with the diagnosis of Churg-Strauss syndrome. CONCLUSION: The authors conclude that they have probably described the first case in the international literature of a venous aneurysm with a Churg-Strauss syndrome and pulmonary embolism.

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The trend to have more cooperative play and the increase of game dynamics in Robocup MSL League motivates the improvement of skills for ball passing and reception. Currently the majority of the MSL teams uses ball handling devices with rollers to have more precise kicks but limiting the capability to kick a moving ball without stopping it and grabbing it. This paper addresses the problem to receive and kick a fast moving ball without having to grab it with a roller based ball handling device. Here, the main difficulty is the high latency and low rate of the measurements of the ball sensing systems, based in vision or laser scanner sensors.Our robots use a geared leg coupled to a motor that acts simultaneously as the kicking device and low level ball sensor. This paper proposes a new method to improve the capability for ball sensing in the kicker, by combining high rate measurements from the torque and energy in the motor and angular position of the kicker leg. The developed method endows the kicker device with an effective ball detection ability, validated in several game situations like in an interception to a fast pass or when chasing the ball where the relative speed from robot to ball is low. This can be used to optimize the kick instant or by the embedded kicker control system to absorb the ball energy.

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Robotica 2012: 12th International Conference on Autonomous Robot Systems and Competitions April 11, 2012, Guimarães, Portugal

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The underground scenarios are one of the most challenging environments for accurate and precise 3d mapping where hostile conditions like absence of Global Positioning Systems, extreme lighting variations and geometrically smooth surfaces may be expected. So far, the state-of-the-art methods in underground modelling remain restricted to environments in which pronounced geometric features are abundant. This limitation is a consequence of the scan matching algorithms used to solve the localization and registration problems. This paper contributes to the expansion of the modelling capabilities to structures characterized by uniform geometry and smooth surfaces, as is the case of road and train tunnels. To achieve that, we combine some state of the art techniques from mobile robotics, and propose a method for 6DOF platform positioning in such scenarios, that is latter used for the environment modelling. A visual monocular Simultaneous Localization and Mapping (MonoSLAM) approach based on the Extended Kalman Filter (EKF), complemented by the introduction of inertial measurements in the prediction step, allows our system to localize himself over long distances, using exclusively sensors carried on board a mobile platform. By feeding the Extended Kalman Filter with inertial data we were able to overcome the major problem related with MonoSLAM implementations, known as scale factor ambiguity. Despite extreme lighting variations, reliable visual features were extracted through the SIFT algorithm, and inserted directly in the EKF mechanism according to the Inverse Depth Parametrization. Through the 1-Point RANSAC (Random Sample Consensus) wrong frame-to-frame feature matches were rejected. The developed method was tested based on a dataset acquired inside a road tunnel and the navigation results compared with a ground truth obtained by post-processing a high grade Inertial Navigation System and L1/L2 RTK-GPS measurements acquired outside the tunnel. Results from the localization strategy are presented and analyzed.

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Proceedings of the International Conference on Computer Vision Theory and Applications, 361-365, 2013, Barcelona, Spain

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In this work we propose the development of a stereo SLS system for underwater inspection operations. We demonstrate how to perform a SLS calibration both in dry and underwater environments using two different methods. The proposed methodology is able to achieve quite accurate results, lower than 1 mm in dry environments. We also display a 3D underwater scan of a known object size, a sea scallop, where the system is able to perform a scan with a global error lower than 2% of the object size.

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We present a novel approach of Stereo Visual Odometry for vehicles equipped with calibrated stereo cameras. We combine a dense probabilistic 5D egomotion estimation method with a sparse keypoint based stereo approach to provide high quality estimates of vehicle’s angular and linear velocities. To validate our approach, we perform two sets of experiments with a well known benchmarking dataset. First, we assess the quality of the raw velocity estimates in comparison to classical pose estimation algorithms. Second, we added to our method’s instantaneous velocity estimates a Kalman Filter and compare its performance with a well known open source stereo Visual Odometry library. The presented results compare favorably with state-of-the-art approaches, mainly in the estimation of the angular velocities, where significant improvements are achieved.

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In this paper we propose a novel fully probabilistic solution to the stereo egomotion estimation problem. We extend the notion of probabilistic correspondence to the stereo case which allow us to compute the whole 6D motion information in a probabilistic way. We compare the developed approach against other known state-of-the-art methods for stereo egomotion estimation, and the obtained results compare favorably both for the linear and angular velocities estimation.

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OBJECTIVE: To assess the frequency and severity of the anomalous origin of the left coronary artery (ALCA) from the pulmonary artery (PA). DESIGN OF THE STUDY: Prospective study of case series between March 1991 and December 1994. SETTING: Referral-based Paediatric Cardiology Department of a Tertiary Care Center. PATIENTS AND METHODS: Five consecutive patients (pts) with anomalous origin of the LCA from the PA; there were three infants aged 4 months and two children one 8 year and one 9 year old. There were three girls and two boys. All pts had clinical and 2D-echo and Doppler investigation prior to cardiac catheterization (CC). Indication for CC was based in the association of symptoms and signs of myocarditis or dilated cardiomyopathy of acute or subacute onset and electrocardiographic (ECG) signs of ischemia in infants. In older patients (pts) diagnosis was suspected mainly from ECG. During CC in all pts, aortograms and when necessary selective coronary angiograms were performed. Surgical correction was performed in all children. In two pts stress exercise ECG and stress Thallium studies before and after surgery were performed. RESULTS: two pts had "adult" an three had "infantile" type of ALCA from the PA. CC was performed and diagnosis was confirmed at surgery in all cases. In one child, correct diagnosis was made by ECO prior to CC and in one case LCA to PA fistula was suspected on Colour-Doppler study. No complications were attributed to CC. Several types of surgery were performed: reimplantation of the ALCA from the PA to the aorta (three pts); tunnel connection of the aorta to the ALCA via the PA (one pt) and left internal mammary to LCA anastomosis (one pt). Two infants died intraoperatively due to extensive myocardial infarction and poor left ventricular function. All the three survivors are asymptomatic after a mean follow up of 34 months. Two oldest pts are currently in New York Heart Association functional class I with normal ECG and improved myocardial perfusion on Thallium scan despite almost total occlusion of LCA at the site of implantation in the aorta as diagnosed on coronary angiogram. CONCLUSIONS: ALCA from PA is associated with major morbidity and mortality. Diagnosis should be suspected in pts with unexplained myocardial ischemia on ECG and even more if it is associated to clinical signs of dilated cardiomyopathy or myocarditis. Careful assessment on ECO and pulsed Doppler and colour flow mapping should make the diagnosis in most cases. Although surgery can be performed based only on ECO diagnosis, we strongly advise for angiography in all cases as in our experience there are false negative diagnosis by ECO. Preoperative Thallium studies can be useful for the selection of the type of surgery as pts with very little viable myocardium will not survive the establishment of a direct systemic to coronary blood flow and may be candidates for heart transplantation.

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Even though in clinical practice carotid cavernous fistulas (CCF) are not a frequent pathology, it should be a diagnostic hypothesis in face of a suggestive clinical presentation. We intended to review the diagnosis and the therapeutics, comparing them with the actual perspectives. Files of 25 patients with the diagnostic hypothesis of CCF, confirmed by conventional angiography in the HSAC Neuroradiology Department, were reviewed. In this group of patients, (5 males and 20 females), the fistulous aetiology was spontaneous in 10 and traumatic in 15. Clinically the symptom most often presented was diplopia (23 cases) and the most frequent encountered sign was ophthalmoplegia (20 cases). Of the Neuroradiologic investigation, CT scan (done to all patients) have shown an prominent superior ophthalmic vein as the most frequent abnormality. Angiographic study was based on Lasjaunias et al protocol (Surgical Neuroangiography, Vol. 2, Springer-Verlag). Surgery was the therapeutic approach for the traumatic fistulas; only 2 of the spontaneous were treated by endovascular route. Three patients are still under observation. In all the others cases there was a fistula exclusion.

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PURPOSE: 1. Identify differences in optic nerve sheath diameter (ONSD) as an indirect measure of intracranial pressure (ICP) in glaucoma patients and a healthy population. 2. Identify variables that may correlate with ONSD in primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) patients. METHODS: Patients with NTG (n = 46) and POAG (n = 61), and healthy controls (n = 42) underwent B-scan ultrasound measurement of ONSD by an observer masked to the patient diagnosis. Intraocular pressure (IOP) was measured in all groups, with additional central corneal thickness (CCT) and visual field defect measurements in glaucomatous patients. Only one eye per patient was selected. Kruskal-Wallis or Mann-Whitney were used to compare the different variables between the diagnostic groups. Spearman correlations were used to explore relationships among these variables. RESULTS: ONSD was not significantly different between healthy, NTG and POAG patients (6.09 ± 0.78, 6.03 ± 0.69, and 5.71 ± 0.83 respectively; p = 0.08). Visual field damage and CCT were not correlated with ONSD in either of the glaucoma groups (POAG, p = 0.31 and 0.44; NTG, p = 0.48 and 0.90 respectively). However, ONSD did correlate with IOP in NTG patients (r = 0.53, p < 0.001), while it did not in POAG patients and healthy controls (p = 0.86, p = 0.46 respectively). Patient's age did not relate to ONSD in any of the groups (p > 0.25 in all groups). CONCLUSIONS: Indirect measurements of ICP by ultrasound assessment of the ONSD may provide further insights into the retrolaminar pressure component in glaucoma. The correlation of ONSD with IOP solely in NTG patients suggests that the translaminar pressure gradient may be of particular importance in this type of glaucoma.

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A 31 year old male Caucasian received a renal cadaveric allograft. Reconstruction of an inferior polar artery was corrected pre-implantation. Delayed graft function occurred leading to dialysis support for one month. Graft biopsies(days 7, 15) showed acute tubular necrosis(ATN) and no rejection. Serial ultrasound (US), performed on average weekly, were compatible with ATN. On day 31, Doppler US and a CAT scan suggested for the first time a pseudoaneurysm adjacent to the implantation of the graft artery on the external iliac artery. For clinical and technical reasons, arteriography was only performed on day 67, when serum creatinine was 3.3 mg/dl. It showed a large pseudoaneurysm with an arteriovenous fistula to the right common iliac vein. Compression of the right external iliac artery was clear. In an attempt to close the arteriovenous fistula, the communication with the pseudoaneurysm was embolised with gelfoam and metallic coils with partial success. One week later, by right femoral approach a covered wallstent was placed immediately below the origin of the graft artery.Subsequent Doppler US and arteriography con-firmed closure of the communication with thepseudoaneurysm and of the arteriovenous fistula. The calibre of the right external iliac artery was then normal. By month 18, serum creatinine is stable at 2.1 mg/dl. We can only speculate on the origin of thepseudoaneurysm and of the AV fistula, whichwere not evident until one month post-transplantation. Backtable surgery was performed on thepolar not the main graft artery. Invasive angiography was irreplaceable in this unusual clinical situation.

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Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica

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The use of minimally invasive surgery for the treatment of lung cancer has been growing worldwide. Between May 2008 and November 2012, we performed 24 videothoracoscopic anatomical lung resections in our department. This includes 22 lobectomies and 2 anatomic segmentectomies, which is known to be a more complex surgery, since it demands a finer dissection of sub-lobar structures. We report the clinical cases of two patients who underwent anatomic segmentectomies. The first one was a 63 year old woman, smoker and with a history of breast cancer 20 years earlier. An incidental 9 mm node was found in the lingula. The patient underwent an anatomic lingulectomy and the frozen section was suggestive of a primary lung cancer. Therefore, we proceeded to a full lymphadenectomy. The final pathology evaluation showed a typical carcinoid tumour (pT1aN0). The second patient was a 50 year old woman, a smoker and with a heavy family history of lung cancer. In a screening CT scan a 8 mm ground glass opacity was identified in the left lower lobe (segment VI). After a VATS wedge resection of the node the frozen section evaluation was compatible with adenocarcinoma. We then proceeded to an anatomic segmentectomy with lymphadenectomy. The definitive pathology evaluation confirmed that it was a pT1a N0 bronchioloalveolar adenocarcinoma. The patients now have 5 and 2 months of follow up respectivelly and neither of them has signs of recurrence and the surgical incision showed a good aesthetic result. Anatomic segmentectomy is the indicated surgery especially in patients with low grade tumours, in early stage lung cancers or in patients without pulmonary function for a lobar resection, and it can be done safely using VATS.