Studio e implementazione di algoritmi per l'elaborazione in tempo reale di segnali biomedici acquisiti con sistemi indossabili

I sistemi indossabili sensorizzati permettono di effettuare un monitoraggio continuo dei principali segnali vitali, quali elettrocardiogramma (ECG), respiro e attività fisica, allo scopo di ottenere informazioni sullo stato di salute del soggetto. La presenza di artefatti nei segnali biomedici acquisiti e la necessità di un intervento tempestivo in caso di alterazioni delle variabili fisiologiche, inducono allo sviluppo di algoritmi di elaborazione in tempo reale. I metodi classici di filtraggio lineare si basano sull'ipotesi che l'informazione utile e il rumore siano su bande frequenziali diverse. Nei casi in cui questa ipotesi non sia verificata, come per gli artefatti da movimento presenti sul segnale ECG, tali metodi non possono essere applicati. Tuttavia, se disponiamo di qualche informazione sul rumore, può essere utilizzata la tecnica di filtraggio adattivo. Un possibile approccio per la rimozione di artefatti da movimento mediante filtro adattivo prevede l'utilizzo di un accelerometro triassiale. Tale dispositivo, utilizzato principalmente per acquisire un segnale legato all'attività fisica, può fornire una misura degli artefatti da movimento se posizionato direttamente sul sistema indossabile. Il segnale ECG infatti può essere visto come la somma di due contributi: un termine utile, che rappresenta l'informazione d'interesse presente nel segnale, e un termine di rumore, dovuto all'artefatto da movimento. L'obiettivo di un approccio basato su un filtraggio di tipo adattivo è stimare il termine di rumore dal segnale acquisito dall'accelerometro, se questi due segnali sono fra loro correlati. Un altro aspetto fondamentale nell'elaborazione in tempo reale del segnale ECG è l'estrazione della frequenza cardiaca. La trasformata wavelet, decomponendo il segnale in blocchi elementari ben localizzati nel tempo e in frequenza, rappresenta uno strumento utile per l'analisi multirisoluzione dei segnali. Questo aspetto può essere sfruttato per rilevare le onde caratteristiche presenti nel segnale ECG, in particolare l'onda R, da cui estrarre la frequenza cardiaca. L'obiettivo di questo lavoro di tesi è lo sviluppo e l'implementazione su un microcontrollore di algoritmi per l'elaborazione in tempo reale di segnali biomedici basati su filtraggi di tipo adattivo, per la rimozione di artefatti, e sulla trasformata wavelet discreta, per l'estrazione della frequenza cardiaca

The impact of airport competition on technical efficiency: A Stochastic Frontier Analysis applied to Italian airports

We investigate how the intensity of competition among airports affects their technical efficiency by computing airports’ markets on the basis of a potential demand approach. We find that the intensity of competition has a negative impact on airports’ efficiency in Italy during the 2005–2008 period. This implies that airports belonging to a local air transportation system where competition is strong exploit their inputs less intensively than do airports with local monopoly power. Furthermore, we find that public airports are more efficient than private and mixed ones. Since public airports take into account the positive externalities created by air transportation in the local economy, they are more willing to subsidize airlines in developing the airports’ connections. Hence, policy makers should provide incentives to implement airports’ specialization in local systems where competition is strong. Moreover, when regulating airport charges, they should take into account the impact of the above externalities.Airport efficiency; stochastic distance function; airport competition

‘We are rolling and vaulting tonight’: sport programmes, urban regeneration and the politics of parkour in Turin, Italy.

The following paper aims to contribute to an interdisciplinary field of enquiry addressing the ways in which lifestyle and informal sports can inform policy debate and development at various levels. It will do so by considering the ambivalent position that parkour is taking within policies of urban and community re-branding enacted in Turin, Italy. Parkour in Turin is an increasingly structured discipline often endorsed by events celebrating the city’s vibrancy, and by local projects that target youth, and promote social participation. However, this discipline implies also a spontaneous and irreverent engagement with urban spaces that often creates frictions and conflicts between traceurs (parkour practitioners) and other actors in relation to what constitutes the public, how it should be used and by whom. Drawing on 14 months of ethnographic research with a group of 20 traceurs predominantly of migrant origins, this study focuses on the participants’ ambivalent engagement with one project promoting social participation through sports in Turin’s urban spaces. Building on the ethnographic material, this paper addresses the emerging relationship between social projects, informal urban practices and emerging forms of creative urbanism. The discussion focuses on the ambiguities and fault lines of urban agendas incorporating lifestyle and informal sports in their (neoliberal) vocabulary of community and place regeneration. However, this paper calls also for the necessity to engage with spontaneous, informal physical practices as a way to acknowledge, and support existing, contested negotiations of citizenship and belonging in urban spaces

A Hardware Generator of Multi-point Distributed Random Numbers for Monte Carlo Simulation

Monte Carlo simulation of weak approximations of stochastic differential equations constitutes an intensive computational task. In applications such as finance, for instance, to achieve "real time" execution, as often required, one needs highly efficient implementations of the multi-point distributed random number generator underlying the simulations. In this paper a fast and flexible dedicated hardware solution on a field programmable gate array is presented. A comparative performance analysis between a software-only and the proposed hardware solution demonstrates that the hardware solution is bottleneck-free, retains the flexibility of the software solution and significantly increases the computational efficiency. Moreover, simulations in applications such as economics, insurance, physics, population dynamics, epidemiology, structural mechanics, chemistry and biotechnology can benefit from the obtained speedup.random number generators; random bit generators; hardware implementation; field programmable gate arrays (FPGAs); Monte Carlo simulation; weak Taylor schemes; multi-point distributed random variables

Convolutional Neural Networks for the segmentation of microcalcification in Mammography Imaging

Cluster of microcalcifications can be an early sign of breast cancer. In this paper we propose a novel approach based on convolutional neural networks for the detection and segmentation of microcalcification clusters. In this work we used 283 mammograms to train and validate our model, obtaining an accuracy of 98.22% in the detection of preliminary suspect regions and of 97.47% in the segmentation task. Our results show how deep learning could be an effective tool to effectively support radiologists during mammograms examination.Comment: 13 pages, 7 figure

New Methods in Cardiac Magnetic Resonance Imaging and Spectroscopy

Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) are non-invasive techniques that provide fundamental information for tissue characterization in normal and diseased myocardium. Indeed, quantitative MRI gives insight into different pathophysiological conditions of myocardial tissue, like inflammation, edema and fibrosis, while MRS allows the quantification of crucial compounds involved in myocardial energy metabolism, such as triglycerides (TGs) and creatine (CR). The purpose of this thesis is to address several methodological challenges that have limited so far the application of these techniques in clinical settings, such as the low signal-to-noise ratio (SNR), the susceptibility to motion, the long scan times and the reproducibility of quantitative parameters. To achieve this purpose, the use of large coil arrays for SNR enhancement in cardiac MRS was investigated and advanced motion compensation strategies were implemented to increase the reproducibility of metabolite quantification. Moreover, in order to assess the regional distribution of myocardial TGs and CR in short scan times, a fast spectroscopic imaging technique was proposed and validated on healthy volunteers. Finally, a quantitative MRI method was implemented on a 3.0 Tesla MRI system for mapping T1 relaxation times in the human heart. The results achieved by the methods proposed in this thesis may facilitate the use of cardiac MRI and MRS in clinical routine for an accurate characterization of myocardial tissue

The old and the new: vaccine hesitancy in the era of the Web 2.0. Challenges and opportunities

The phenomenon known as Vaccine hesitancy (a term that includes the concepts of indecision, uncertainty, delay, reluctance) is complex and closely linked to the different contexts, with different determinants: historical period, geographical areas, political situation, as complacency, convenience and confidence towards vaccines. The World Health Organization (WHO) recommends to constantly monitor vaccine hesitancy and any proxy of it. Given the growing importance and pervasiveness of the information and communication technologies (ICTs), the new media could be exploited for a real-time tracking of vaccination-related perception by the lay-people, enabling health-care workers to actively engage themselves and to plan ad hoc communication strategies. The analysis of so-called "sentiments" expressed through the new media (such as Twitter), the real-time tracking of web-related activities enabled by Google Trends, combined with online specific "surveys" on well-defined themes administered to target groups (like health-care workers) may constitute the "Fast data monitoring system", enabling to get a snapshot on the perception of vaccination in that place and at that time. This type of dashboard could be a strategic tool for public services, to organize targeted communication actions aimed at containing Vaccine hesitancy

Social determinants, ethical issues and future challenge of tuberculosis in a pluralistic society: the example of Israel

Tuberculosis is a very serious respiratory infectious disease, caused by the bacillus Mycobacterium tuberculosis, which generates a relevant societal and clinical burden. It has always represented a permanent concern and a public health challenge over the course of human history, because of its severe epidemiological, and economic-financial implications. The present review aims at over-viewing the impact on tuberculosis on the Israeli healthcare system, its temporal trend and evolution, stratified according to ethnicities and minorities, the need of establishing new facilities and implementing screening techniques, public health strategies and diagnostic tests, following massive immigration waves from countries characterized by a high incidence rate of tuberculosis during the fifties-sixties until the nineties, and the policies implemented by the Israeli government in the control, management and treatment of tuberculosis, as well as the role played by Israeli prominent scientists in discovering new druggable targets and finding bioactive compounds and bio-molecules in the fight against tuberculosis. Israel represents a unique, living laboratory in which features of developed and developing countries mix together. This country as a case-study of immigrant, pluralistic society underlines the importance of adopting a culturally-sensitive community intervention approach. The understanding of the subtle interplay between race/ethnic host and pathogen factors, including the role of gene variations and polymorphisms can pave the way for a personalized treatment and management of tuberculosis patients, contributing to the development of new tools for targeted tuberculosis therapeutics, immunodiagnostics and vaccination products