15 resultados para Automated system
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Farm animals may serve as models for evaluating social networks in a controlled environment. We used an automated system to track, at fine temporal and spatial resolution (once per minute, +/- 50 cm) every individual in six herds of dairy cows (Bos taurus). We then analysed the data using social network analyses. Relationships were based on non-random attachment and avoidance relationships in respect to synchronous use and distances observed in three different functional areas (activity, feeding and lying). We found that neither synchrony nor distance between cows was strongly predictable among the three functional areas. The emerging social networks were tightly knit for attachment relationships and less dense for avoidance relationships. These networks loosened up from the feeding and lying area to the activity area, and were less dense for relationships based on synchronicity than on median distance with respect to node degree, relative size of the largest cluster, density and diameter of the network. In addition, synchronicity was higher in dyads of dairy cows that had grown up together and shared their last dry period. This last effect disappeared with increasing herd size. Dairy herds can be characterized by one strongly clustered network including most of the herd members with many non-random attachment and avoidance relationships. Closely synchronous dyads were composed of cows with more intense previous contact. The automatic tracking of a large number of individuals proved promising in acquiring the data necessary for tackling social network analyses.
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OBJECTIVES: The C-Port System (Cardica, Inc, Redwood City, Calif) integrates in one tool all functions necessary to enable rapid automated distal coronary anastomoses. The goal of this prospective, nonrandomized, and multicenter study is to determine the safety and efficacy of this novel anastomotic system. METHODS: Five centers enrolled 133 patients awaiting elective coronary artery bypass grafting surgery. Outcome variables were intraoperative device performance, incidence of device-related adverse events, predischarge and 6-month angiographic graft patency, and 12-month clinical outcome. Independent core laboratories performed qualitative and quantitative angiographic and computed tomographic assessments. RESULTS: The C-Port was used to perform a vein-to-coronary anastomosis in 130 patients. Intraoperative conversion to a hand-sewn anastomosis was necessary in 11 patients because of inadequate target site preparation, inappropriate target vessel selection, or both. Inadequate blood flow related to poor runoff required conversion in 3 additional patients. Three patients died before discharge of causes unrelated to the device. At discharge, 113 patients had a C-Port implant in place, and 104 C-Port anastomoses were studied by means of angiography, resulting in 100 FitzGibbon A, 3 FitzGibbon B, and 1 FitzGibbon 0 classifications. At 6 months, one additional patient died of a device-unrelated cause, and 98 patients were evaluated by means of angiography (n = 89). Overall patency (FitzGibbon A) was 92.1%. Three C-Port anastomoses were rated FitzGibbon B, and 4 were rated FitzGibbon 0. At 12 months, 107 (98.2%) of 109 alive patients were followed up, without any reports of device-related major adverse cardiac events. CONCLUSIONS: The C-Port System allows for a rapid, reliable, and compliant distal anastomosis and yields favorable 6-month angiographic and 12-month clinical results when compared with published studies.
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BACKGROUND & AIMS: Refractory ascites (RA) affects 10% of patients with advanced cirrhosis and ascites. Usual therapy includes large volume paracentesis, and in selected patients, a transjugular portosystemic shunt (TIPS). These therapies may be associated with increased morbidity: paracentesis may induce circulatory dysfunction and impair quality of life and TIPS may induce encephalopathy and is associated with increased mortality in patients with severe liver dysfunction. We present the results of a multicenter, non-randomized trial to assess the safety and efficacy of a new automated pump system for treatment of RA. METHODS: Forty patients at 9 centers (February 2010-June 2011) received an implanted pump for the automated removal of ascites from the peritoneal cavity into the bladder, from where it was eliminated through normal urination. Patients were followed-up for 6months. The primary study outcome was safety. Secondary outcomes included recurrence of tense ascites and pump performance. RESULTS: Surgical complications occurred early in the study and became less frequent. The pump system removed 90% of the ascites and significantly reduced the median number of large volume paracentesis per month [3.4 (range 1-6) vs. 0.2 (range 0-4); p <0.01]. Cirrhosis-related adverse events decreased along follow-up. CONCLUSIONS: The automated pump seems an efficacious tool to move out ascites from the peritoneal cavity to the bladder. Its safety is still moderate, but a broad use in different countries will improve the surgical technique as well as the medical surveillance. A prospective randomized clinical trial vs. large volume paracentesis is underway to confirm these preliminary results.
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The multi-target screening method described in this work allows the simultaneous detection and identification of 700 drugs and metabolites in biological fluids using a hybrid triple-quadrupole linear ion trap mass spectrometer in a single analytical run. After standardization of the method, the retention times of 700 compounds were determined and transitions for each compound were selected by a "scheduled" survey MRM scan, followed by an information-dependent acquisition using the sensitive enhanced product ion scan of a Q TRAP hybrid instrument. The identification of the compounds in the samples analyzed was accomplished by searching the tandem mass spectrometry (MS/MS) spectra against the library we developed, which contains electrospray ionization-MS/MS spectra of over 1,250 compounds. The multi-target screening method together with the library was included in a software program for routine screening and quantitation to achieve automated acquisition and library searching. With the help of this software application, the time for evaluation and interpretation of the results could be drastically reduced. This new multi-target screening method has been successfully applied for the analysis of postmortem and traffic offense samples as well as proficiency testing, and complements screening with immunoassays, gas chromatography-mass spectrometry, and liquid chromatography-diode-array detection. Other possible applications are analysis in clinical toxicology (for intoxication cases), in psychiatry (antidepressants and other psychoactive drugs), and in forensic toxicology (drugs and driving, workplace drug testing, oral fluid analysis, drug-facilitated sexual assault).
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Vertebroplasty is a minimally invasive procedure with many benefits; however, the procedure is not without risks and potential complications, of which leakage of the cement out of the vertebral body and into the surrounding tissues is one of the most serious. Cement can leak into the spinal canal, venous system, soft tissues, lungs and intradiscal space, causing serious neurological complications, tissue necrosis or pulmonary embolism. We present a method for automatic segmentation and tracking of bone cement during vertebroplasty procedures, as a first step towards developing a warning system to avoid cement leakage outside the vertebral body. We show that by using active contours based on level sets the shape of the injected cement can be accurately detected. The model has been improved for segmentation as proposed in our previous work by including a term that restricts the level set function to the vertebral body. The method has been applied to a set of real intra-operative X-ray images and the results show that the algorithm can successfully detect different shapes with blurred and not well-defined boundaries, where the classical active contours segmentation is not applicable. The method has been positively evaluated by physicians.
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The authors describe the use of the Cardica C-Port xA Distal Anastomosis System to perform an automated, high-flow extracranial-intracranial bypass. The C-Port system has been developed and tested in coronary artery bypass surgery for rapid distal coronary artery anastomoses. Air-powered, it performs an automated end-to-side anastomosis within seconds by nearly simultaneously making an arteriotomy and inserting 13 microclips into the graft and recipient vessel. Intracranial use of the device was first simulated in a cadaver prepared for microsurgical anatomical dissection. The authors used this system in a 43-year-old man who sustained a subarachnoid hemorrhage after being assaulted and was found to have a traumatic pseudoaneurysm of the proximal intracranial internal carotid artery. The aneurysm appeared to be enlarging on serial imaging studies and it was anticipated that a bypass would probably be needed to treat the lesion. An end-to-side bypass was performed with the C-Port system using a saphenous vein conduit extending from the common carotid artery to the middle cerebral artery. The bypass was demonstrated to be patent on intraoperative and postoperative arteriography. The patient had a temporary hyperperfusion syndrome and subsequently made a good neurological recovery. The C-Port system facilitates the performance of a high-flow extracranial-intracranial bypass with short periods of temporary arterial occlusion. Because of the size and configuration of the device, its use is not feasible in all anatomical situations that require a high-flow bypass; however it is a useful addition to the armamentarium of the neurovascular surgeon.
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BACKGROUND: In this paper, we present a new method for the calibration of a microscope and its registration using an active optical tracker. METHODS: Practically, both operations are done simultaneously by moving an active optical marker within the field of view of the two devices. The IR LEDs composing the marker are first segmented from the microscope images. By knowing their corresponding three-dimensional (3D) position in the optical tracker reference system, it is possible to find the transformation matrix between the referential of the two devices. Registration and calibration parameters can be extracted directly from that transformation. In addition, since the zoom and focus can be modified by the surgeon during the operation, we propose a spline based method to update the camera model to the new setup. RESULTS: The proposed technique is currently being used in an augmented reality system for image-guided surgery in the fields of ear, nose and throat (ENT) and craniomaxillofacial surgeries. CONCLUSIONS: The results have proved to be accurate and the technique is a fast, dynamic and reliable way to calibrate and register the two devices in an OR environment.
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OBJECT: Preliminary experience with the C-Port Flex-A Anastomosis System (Cardica, Inc.) to enable rapid automated anastomosis has been reported in coronary artery bypass surgery. The goal of the current study was to define the feasibility and safety of this method for high-flow extracranial-intracranial (EC-IC) bypass surgery in a clinical series. METHODS: In a prospective study design, patients with symptomatic carotid artery (CA) occlusion were selected for C-Port-assisted high-flow EC-IC bypass surgery if they met the following criteria: 1) transient or moderate permanent symptoms of focal ischemia; 2) CA occlusion; 3) hemodynamic instability; and 4) had provided informed consent. Bypasses were done using a radial artery graft that was proximally anastomosed to the superficial temporal artery trunk, the cervical external, or common CA. All distal cerebral anastomoses were performed on M2 branches using the C-Port Flex-A system. RESULTS: Within 6 months, 10 patients were enrolled in the study. The distal automated anastomosis could be accomplished in all patients; the median temporary occlusion time was 16.6+/-3.4 minutes. Intraoperative digital subtraction angiography (DSA) confirmed good bypass function in 9 patients, and in 1 the anastomosis was classified as fair. There was 1 major perioperative complication that consisted of the creation of a pseudoaneurysm due to a hardware problem. In all but 1 case the bypass was shown to be patent on DSA after 7 days; furthermore, in 1 patient a late occlusion developed due to vasospasm after a sylvian hemorrhage. One-week follow-up DSA revealed transient asymptomatic extracranial spasm of the donor artery and the radial artery graft in 1 case. Two patients developed a limited zone of infarction on CT scanning during the follow-up course. CONCLUSIONS: In patients with symptomatic CA occlusion, C-Port Flex-A-assisted high-flow EC-IC bypass surgery is a technically feasible procedure. The system needs further modification to achieve a faster and safer anastomosis to enable a conclusive comparison with standard and laser-assisted methods for high-flow bypass surgery.
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Manual counting of bacterial colony forming units (CFUs) on agar plates is laborious and error-prone. We therefore implemented a colony counting system with a novel segmentation algorithm to discriminate bacterial colonies from blood and other agar plates.A colony counter hardware was designed and a novel segmentation algorithm was written in MATLAB. In brief, pre-processing with Top-Hat-filtering to obtain a uniform background was followed by the segmentation step, during which the colony images were extracted from the blood agar and individual colonies were separated. A Bayes classifier was then applied to count the final number of bacterial colonies as some of the colonies could still be concatenated to form larger groups. To assess accuracy and performance of the colony counter, we tested automated colony counting of different agar plates with known CFU numbers of S. pneumoniae, P. aeruginosa and M. catarrhalis and showed excellent performance.
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BACKGROUND Electrochemical conversion of xenobiotics has been shown to mimic human phase I metabolism for a few compounds. MATERIALS & METHODS Twenty-one compounds were analyzed with a semiautomated electrochemical setup and mass spectrometry detection. RESULTS The system was able to mimic some metabolic pathways, such as oxygen gain, dealkylation and deiodination, but many of the expected and known metabolites were not produced. CONCLUSION Electrochemical conversion is a useful approach for the preparative synthesis of some types of metabolites, but as a screening method for unknown phase I metabolites, the method is, in our opinion, inferior to incubation with human liver microsomes and in vivo experiments with laboratory animals, for example.
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BACKGROUND A precise detection of volume change allows for better estimating the biological behavior of the lung nodules. Postprocessing tools with automated detection, segmentation, and volumetric analysis of lung nodules may expedite radiological processes and give additional confidence to the radiologists. PURPOSE To compare two different postprocessing software algorithms (LMS Lung, Median Technologies; LungCARE®, Siemens) in CT volumetric measurement and to analyze the effect of soft (B30) and hard reconstruction filter (B70) on automated volume measurement. MATERIAL AND METHODS Between January 2010 and April 2010, 45 patients with a total of 113 pulmonary nodules were included. The CT exam was performed on a 64-row multidetector CT scanner (Somatom Sensation, Siemens, Erlangen, Germany) with the following parameters: collimation, 24x1.2 mm; pitch, 1.15; voltage, 120 kVp; reference tube current-time, 100 mAs. Automated volumetric measurement of each lung nodule was performed with the two different postprocessing algorithms based on two reconstruction filters (B30 and B70). The average relative volume measurement difference (VME%) and the limits of agreement between two methods were used for comparison. RESULTS At soft reconstruction filters the LMS system produced mean nodule volumes that were 34.1% (P < 0.0001) larger than those by LungCARE® system. The VME% was 42.2% with a limit of agreement between -53.9% and 138.4%.The volume measurement with soft filters (B30) was significantly larger than with hard filters (B70); 11.2% for LMS and 1.6% for LungCARE®, respectively (both with P < 0.05). LMS measured greater volumes with both filters, 13.6% for soft and 3.8% for hard filters, respectively (P < 0.01 and P > 0.05). CONCLUSION There is a substantial inter-software (LMS/LungCARE®) as well as intra-software variability (B30/B70) in lung nodule volume measurement; therefore, it is mandatory to use the same equipment with the same reconstruction filter for the follow-up of lung nodule volume.
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In electroweak-boson production processes with a jet veto, higher-order corrections are enhanced by logarithms of the veto scale over the invariant mass of the boson system. In this paper, we resum these Sudakov logarithms at next-to-next-to-leading logarithmic accuracy and match our predictions to next-to-leading-order (NLO) fixed-order results. We perform the calculation in an automated way, for arbitrary electroweak final states and in the presence of kinematic cuts on the leptons produced in the decays of the electroweak bosons. The resummation is based on a factorization theorem for the cross sections into hard functions, which encode the virtual corrections to the boson production process, and beam functions, which describe the low-pT emissions collinear to the beams. The one-loop hard functions for arbitrary processes are calculated using the MadGraph5_aMC@NLO framework, while the beam functions are process independent. We perform the resummation for a variety of processes, in particular for W+W− pair production followed by leptonic decays of the W bosons.
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AMS-14C applications often require the analysis of small samples. Such is the case of atmospheric aerosols where frequently only a small amount of sample is available. The ion beam physics group at the ETH, Zurich, has designed an Automated Graphitization Equipment (AGE III) for routine graphite production for AMS analysis from organic samples of approximately 1 mg. In this study, we explore the potential use of the AGE III for graphitization of particulate carbon collected in quartz filters. In order to test the methodology, samples of reference materials and blanks with different sizes were prepared in the AGE III and the graphite was analyzed in a MICADAS AMS (ETH) system. The graphite samples prepared in the AGE III showed recovery yields higher than 80% and reproducible 14C values for masses ranging from 50 to 300 lg. Also, reproducible radiocarbon values were obtained for aerosol filters of small sizes that had been graphitized in the AGE III. As a study case, the tested methodology was applied to PM10 samples collected in two urban cities in Mexico in order to compare the source apportionment of biomass and fossil fuel combustion. The obtained 14C data showed that carbonaceous aerosols from Mexico City have much lower biogenic signature than the smaller city of Cuernavaca.
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Background: Diabetes mellitus is spreading throughout the world and diabetic individuals have been shown to often assess their food intake inaccurately; therefore, it is a matter of urgency to develop automated diet assessment tools. The recent availability of mobile phones with enhanced capabilities, together with the advances in computer vision, have permitted the development of image analysis apps for the automated assessment of meals. GoCARB is a mobile phone-based system designed to support individuals with type 1 diabetes during daily carbohydrate estimation. In a typical scenario, the user places a reference card next to the dish and acquires two images using a mobile phone. A series of computer vision modules detect the plate and automatically segment and recognize the different food items, while their 3D shape is reconstructed. Finally, the carbohydrate content is calculated by combining the volume of each food item with the nutritional information provided by the USDA Nutrient Database for Standard Reference. Objective: The main objective of this study is to assess the accuracy of the GoCARB prototype when used by individuals with type 1 diabetes and to compare it to their own performance in carbohydrate counting. In addition, the user experience and usability of the system is evaluated by questionnaires. Methods: The study was conducted at the Bern University Hospital, “Inselspital” (Bern, Switzerland) and involved 19 adult volunteers with type 1 diabetes, each participating once. Each study day, a total of six meals of broad diversity were taken from the hospital’s restaurant and presented to the participants. The food items were weighed on a standard balance and the true amount of carbohydrate was calculated from the USDA nutrient database. Participants were asked to count the carbohydrate content of each meal independently and then by using GoCARB. At the end of each session, a questionnaire was completed to assess the user’s experience with GoCARB. Results: The mean absolute error was 27.89 (SD 38.20) grams of carbohydrate for the estimation of participants, whereas the corresponding value for the GoCARB system was 12.28 (SD 9.56) grams of carbohydrate, which was a significantly better performance ( P=.001). In 75.4% (86/114) of the meals, the GoCARB automatic segmentation was successful and 85.1% (291/342) of individual food items were successfully recognized. Most participants found GoCARB easy to use. Conclusions: This study indicates that the system is able to estimate, on average, the carbohydrate content of meals with higher accuracy than individuals with type 1 diabetes can. The participants thought the app was useful and easy to use. GoCARB seems to be a well-accepted supportive mHealth tool for the assessment of served-on-a-plate meals.