603 research outputs found

    Data acquisition systems with intelligent trigger capability

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    Two data acquisition systems, based on two solutions for improving the performance, are here presented. The first one, fully analog, is able to generate a voltage impulse at the occurrence of a transient phenomenon on the stationary waveform being monitored. In the second system the acquisition process is regulated by absolute value of the derivative of the signal under analysis. This system is realized with Field Programmable Gate Array technology. All theoretical relations underlying the proposed solutions are first discussed. Their most relevant hardware and software features are then described. A suitable measurement apparatus is set up for assessing the performance of both solutions, and the obtained results are finally given. (c) 2005 Elsevier Ltd. All rights reserved

    Information redundancy neglect versus overconfidence: a social learning experiment

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    We study social learning in a continuous action space experiment. Subjects, acting in sequence, state their belief about the value of a good, after observing their predecessors' statements and a private signal. We compare the behavior in the laboratory with the Perfect Bayesian Equilibrium prediction and the predictions of bounded rationality models of decision making: the redundancy of information neglect model and the overconfidence model. The results of our experiment are in line with the predictions of the overconfidence model and at odds with the others'

    A Wearable Brain-Computer Interface Instrument for Augmented Reality-Based Inspection in Industry 4.0

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    This paper proposes a wearable monitoring system for inspection in the framework of Industry 4.0. The instrument integrates augmented reality (AR) glasses with a noninvasive single-channel brain-computer interface (BCI), which replaces the classical input interface of AR platforms. Steady-state visually evoked potentials (SSVEP) are measured by a single-channel electroencephalography (EEG) and simple power spectral density analysis. The visual stimuli for SSVEP elicitation are provided by AR glasses while displaying the inspection information. The real-time metrological performance of the BCI is assessed by the receiver operating characteristic curve on the experimental data from 20 subjects. The characterization was carried out by considering stimulation times from 10.0 down to 2.0 s. The thresholds for the classification were found to be dependent on the subject and the obtained average accuracy goes from 98.9% at 10.0 s to 81.1% at 2.0 s. An inspection case study of the integrated AR-BCI device shows encouraging accuracy of about 80% of lab values

    Latest Advancements in SSVEPs Classification for Single-Channel, Extended Reality-based Brain-Computer Interfaces

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    This work details the latest advancements on a single-channel, reactive Brain-Computer Interfaces developed at the Interdepartmental Research Center in Health Management and Innovation in Healthcare (CIRMIS) of the University of Naples Federico II. The proposed instrumentation is based on Extended Reality (XR) and exploits the acquisition and classification of the Steady-State Visually Evoked Potentials (SSVEPs). In particular, an XR headset is employed for generating the flickering stimuli necessary to the SSVEP elicitation. The users brain signals are captured by means of a highly wearable and portable electroencephalografic acquisition unit, which is connected to a portable processing unit in charge of processing in real time the incoming data. In this way, a deeper interaction between users and external devices with respect to traditional architectures is guaranteed. The classification capability of the proposed instrument has been significantly improved over the years. Currently, in fact, a classification accuracy up to 90 % is obtained with at least 2 s of acquisition time

    Metrological performance of a single-channel brain-computer interface based on motor imagery

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    In this paper, the accuracy in classifying Motor Imagery (MI) tasks for a Brain-Computer Interface (BCI) is analyzed. Electroencephalographic (EEG) signals were taken into account, notably by employing one channel per time. Four classes were to distinguish, i.e. imagining the movement of left hand, right hand, feet, or tongue. The dataset '2a' of BCI Competition IV (2008) was considered. Brain signals were processed by applying a short-time Fourier transform, a common spatial pattern filter for feature extraction, and a support vector machine for classification. With this work, the aim is to give a contribution to the development of wearable MI-based BCIs by relying on single channel EEG

    Impact of Sleeve Gastrectomy on Weight Loss, Glucose Homeostasis, and Comorbidities in Severely Obese Type 2 Diabetic Subjects

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    This study was undertaken to assess medium-term effects of laparoscopic sleeve gastrectomy (LSG) on body weight and glucose homeostasis in severely obese type 2 diabetic (T2DM) subjects. Twenty-five obese T2DM subjects (10 M/15 F, age 45 ± 9 years, BMI 48 ± 8 kg/m2, M ± SD) underwent evaluation of anthropometric/clinical parameters and glucose homeostasis before, 3 and 9–15 months after LSG. Mean BMI decreased from 48 ± 8 kg/m2 to 40 ± 9 kg/m2 (P < .001) at 3 months and 34 ± 6 kg/m2 (P < .001) at 9–15 months after surgery. Remission of T2DM (fasting plasma glucose < 126 mg/dL and HbA1c < 6.5% in the absence of hypoglycemic treatment) occurred in all patients but one. There was a remarkable reduction in the percentage of patients requiring antihypertensive and hypolipidemic drugs. Our study shows that LSG is effective in producing a significant and sustained weight loss and improving glucose homeostasis in severely obese T2DM patients

    JCV-specific T-cells producing IFN-gamma are differently associated with PmL occurrence in HIV patients and liver transplant recipients

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    Aim of this work was to investigate a possible correlation between the frequency of JCV-specific T-cells and PML occurrence in HIV-infected subjects and in liver transplant recipients. A significant decrease of JCV-specific T-cells was observed in HIV-PML subjects, highlighting a close relation between JCV-specific T-cell immune impairment and PML occurrence in HIV-subjects. Interestingly, liver-transplant recipients (LTR) showed a low frequency of JCV-specific T-cells, similar to HIV-PML subjects. Nevertheless, none of the enrolled LTR developed PML, suggesting the existence of different immunological mechanisms involved in the maintenance of a protective immune response in LT

    A ML-based Approach to Enhance Metrological Performance of Wearable Brain-Computer Interfaces

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    In this paper, the adoption of Machine Learning (ML) classifiers is addressed to improve the performance of highly wearable, single-channel instrumentation for Brain-Computer Interfaces (BCIs). The proposed BCI is based on the classification of Steady-State Visually Evoked Potentials (SSVEPs). In this setup, Augmented Reality Smart Glasses are used to generate and display the flickering stimuli for the SSVEP elicitation. An experimental campaign was conducted on 20 adult volunteers. Successively, a Leave-One-Subject-Out Cross Validation was performed to validate the proposed algorithm. The obtained experimental results demonstrate that suitable ML-based processing strategies outperform the state-of-the-art techniques in terms of classification accuracy. Furthermore, it was also shown that the adoption of an inter-subjective model successfully led to a decrease in the 3-σ uncertainty: this can facilitate future developments of ready-to-use systems

    Fine-needle cytology in the follow-up of breast carcinoma

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    The postoperative follow-up strategies for breast carcinoma (BC) utilize different procedures; the aim of this study was to investigate the role of fine-needle cytology (FNC) in the follow-up of BC patients. Two hundred sixty-six FNC samples from 190 BC patients have been reviewed. The target anatomical sites were 190 breast including 155 ipsilateral and 145 contralateral breast lesions and 76 extra-mammary nodules. Extra-mammary lesions included lymph nodes, thyroidal nodules, soft tissue lesions, (subcutaneous and sub-scars), salivary glands and deep located masses. Diagnostic distribution of the breast lesions was as follows: 51 positive, 15 indeterminate/suspicious, 119 negative and 5 inadequate. Positive cases included 43 ipsilateral and 8 contralateral BC, 9 BC in different quadrants from those of onset of the first BC. Sensitivity, specificity and accuracy have been 90, 91 and 90&, respectively. FNC, in a correct setting, is a reliable and effective method for the follow-up management of BC patients

    Preparation and PET/CT imaging of implant directed 68Ga-labeled magnetic nanoporous silica nanoparticles

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    Background: Implant infections caused by biofilm forming bacteria are a major threat in orthopedic surgery. Delivering antibiotics directly to an implant affected by a bacterial biofilm via superparamagnetic nanoporous silica nanoparticles could present a promising approach. Nevertheless, short blood circulation half-life because of rapid interactions of nanoparticles with the host’s immune system hinder them from being clinically used. The aim of this study was to determine the temporal in vivo resolution of magnetic nanoporous silica nanoparticle (MNPSNP) distribution and the effect of PEGylation and clodronate application using PET/CT imaging and gamma counting in an implant mouse model. Methods: PEGylated and non-PEGylated MNPSNPs were radiolabeled with gallium-68 (68Ga), implementing the chelator tris(hydroxypyridinone). 36 mice were included in the study, 24 mice received a magnetic implant subcutaneously on the left and a titanium implant on the right hind leg. MNPSNP pharmacokinetics and implant accumulation was analyzed in dependence on PEGylation and additional clodronate application. Subsequently gamma counting was performed for further final analysis. Results: The pharmacokinetics and biodistribution of all radiolabeled nanoparticles could clearly be visualized and followed by dynamic PET/CT imaging. Both variants of 68Ga-labeled MNPSNP accumulated mainly in liver and spleen. PEGylation of the nanoparticles already resulted in lower liver uptakes. Combination with macrophage depletion led to a highly significant effect whereas macrophage depletion alone could not reveal significant differences. Although MNPSNP accumulation around implants was low in comparison to the inner organs in PET/CT imaging, gamma counting displayed a significantly higher %I.D./g for the tissue surrounding the magnetic implants compared to the titanium control. Additional PEGylation and/or macrophage depletion revealed no significant differences regarding nanoparticle accumulation at the implantation site. Conclusion: Tracking of 68Ga-labeled nanoparticles in a mouse model in the first critical hours post-injection by PET/CT imaging provided a better understanding of MNPSNP distribution, elimination and accumulation. Although PEGylation increases circulation time, nanoparticle accumulation at the implantation site was still insufficient for infection treatment and additional efforts are needed to increase local accumulation
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