124 research outputs found
Indoor tracking using unmanned aerial vehicles
No full textSearch and rescue operations during emergencies are complex missions that put at risk the life of first responders. The main challenge is to detect the trapped and injured people inside buildings damaged by different hazards. With a tool showing on a map the number, location and health status of victims, first responders would be able to significantly reduce the evacuation time and save more lives. In this paper, an innovative real-time indoor localization system using Unmanned Aerial Vehicles (UAVs) is proposed. The system includes anchor nodes (antennas) that are mounted on three UAVs flying outside the building and can track the position of people wearing a smart bracelet (tags). The system allows measuring both the absolute and relative location between groups of nodes in 3D without relying on any fixed communication infrastructure that could fail because of the disruptive event. In addition, vital parameters such as heart rate and body temperature can be monitored for each victim and rescuer wearing the bracelet. Each UAV collects, processes, and transfers the data to a portable gateway. A software application with a graphical user interface was developed to display the real-time position of the UAVs and tags with a color-coded indication of the accuracy. Preliminary results of the on-field tests of the systems are presented and discussed
A Compartment-Based Mathematical Model for Studying Convective Aerosol Transport in Newborns Receiving Nebulized Drugs during Noninvasive Respiratory Support
No full textNebulization could be a valuable solution to administer drugs to neonates receiving noninvasive respiratory support. Small and irregular tidal volumes and air leaks at the patient interface, which are specific characteristics of this patient population and are primarily responsible for the low doses delivered to the lung (DDL) found in this application, have not been thoroughly addressed in in vitro and in vivo studies for quantifying DDL. Therefore, we propose a compartment-based mathematical model able to describe convective aerosol transport mechanisms to complement the existing deposition models. Our model encompasses a mechanical ventilator, a nebulizer, and the patient; the model considers the gas flowing between compartments, including air leaks at the patient–ventilator interface. Aerosol particles are suspended in the gas flow and homogeneously distributed. The impact of breathing pattern variability, volume of the nebulizer, and leaks level on DDL is assessed in representative conditions. The main finding of this study is that convective mechanisms associated to air leaks and breathing patterns with tidal volumes smaller than the nebulizer dramatically reduce the DDL (up to 70%). This study provides a possible explanation to the inconsistent results of drug aerosolization in clinical studies and may provide guidance to improve nebulizer design and clinical procedures
Missione dei Padri Passionisti in Italia
No full textIl Vescovo Mons. Semeraro con i Missionari Passionisti: P. Antonino Nuzzi, P. Raffaele Riccitelli, P. Gerardo Nesta, P. Bonaventura Perrone di Trepuzzi (LE), P. Arcangelo Paladini, P. Amedeo Tarantini di Novoli (LE), P. Giuseppe di Carbonara.NOTE: evento esteso a più giornate, 1964/03/8-2
Analysis of multi-source satellite-derived displacement data for structural monitoring of masonry heritage buildings
No full textHistorical masonry structures, such as churches and towers, represent a fundamental part of our cultural heritage but are particularly vulnerable due to both aging and the external influences they are subjected to. In this context, Structural Health Monitoring (SHM) plays a crucial role in assessing structural integrity and preventing damage. In recent years, satellite remote sensing data, such as those obtained through interferometric techniques (InSAR), have gained increasing relevance in SHM applications, also due to the free availability of pre-processed datasets fro missions like Sentinel-1 (European Ground Motion Service - EGMS). However, the direct use of such data may often be limited, as they are provided in a pre-processed form, reducing the user ability to customize and adapt the analysis. This study presents a comparison between pre-processed EGMS data and data obtained through user-controlled processing using dedicated software, with the aim of evaluating the advantages and limitations of each approach. Using data obtained through user-controlled processing allows for the targeted selection of reliable points while discarding those considered inconsistent or of low quality, thus ensuring a more robust and tailored analysis. This processed data could be useful to calibrate a numerical model, enabling the joint optimization of mechanical parameters and external imposed actions (e.g., displacements), thus improving the prediction of structural behaviour and supporting more robust SHM models
Seismic vulnerability assessment of RC bridge piers strengthened with GFRP rebars: A case study
No full textThe use of Glass Fiber Reinforced Polymer (GFRP) bars for retrofitting bridges piers under seismic excitation is an advanced technique that offers several benefits due to the material’s unique properties, in terms of high strength-to-weight ratio, insensitivity to corrosion, and high durability. Throughout the world, a large number of outdated structures, particularly those made of reinforced concrete, require urgent repairing interventions due to a variety of factors, including environmental effects, inadequate construction details, and neglected maintenance. Engineers who want to increase the longevity and safety of bridge structures in seismic regions can find great benefits in the application of GFRP. An existing bridge is considered as case study. The strengthening design strategy aims to increase the lateral resistance by slightly altering the lateral displacement ductility. To this aim, a hybrid retro-fitting with steel and GFRP rebars is designed to be applied through the jacketing technique. The force-deformation curves of the nonlinear plastic hinges are determined using a fiber approach, after validation of the constitutive models. A Pushover Analysis (POA) with lumped plasticity is implemented in order to compare the seismic response of the original structure with the retrofitted one. The capacity of the structure and thus its Seismic Vulnerability Index (SVI) and differences in overall structural response areevaluated
Seismic behaviour at ultimate limit state of reinforced concrete structures retrofitted with glass fiber reinforced polymer rebars
No full textThe use of Glass Fiber Reinforced Polymer (GFRP) bars in the framework of retrofitting Reinforced Concrete (RC) structures subjected to seismic action is an advanced technique that offers several benefits due to the material's unique properties. The resulting hybrid reinforcement, consisting of preexisting steel reinforcement in the inner part of the cross-section and additional GFRP bars embedded in the external jacketing, increases the load-bearing capacity while reducing the overall structural element's susceptibility to subsequent corrosion phenomena, saving future maintenance costs. Designers seeking to enhance the durability and safety of RC structures in seismic zones might considerably benefit from implementing hybrid reinforcing systems. The present study analyses a 2D RC multistorey frame as a case study. Two distinct retrofitting interventions are compared: a traditional jacketing, with steel reinforcement, and a GFRP jacketing. The structural behaviour is assessed by, first, computing the moment-curvature relationship of nonlinear plastic hinges, obtained by considering the different failure modes of hybrid reinforced concrete sections, which lead to different postyielding branches. Then, a pushover analysis is performed using a lumped plasticity approach to monitor the activation and evolution of plastic hinges, thus assessing the load-bearing capacity, ductility and energy dissipation of the frames
Dynamic identification of a historical masonry building: the case study of palazzo Rosciano
No full textThis paper focuses on the dynamic characterization of a historical building located in the port city of Livorno (Italy), Palazzo Rosciano. It is a masonry structure built in the second half of the 1600 and fully renovated in the nineties to accommodate the offices of the North Tyrrhenian Sea Port Authority. The research was carried out starting from a preliminary inspection and a historical-critical analysis. Then, a detailed geometric survey was carried out using a 3D laser scanner. To define the mechanical properties of materials a series of minor destructive tests, i.e., flat jacks, shove test, and penetrometer, were performed. A structural health monitoring campaign was also carried out under ambient vibrations using a wireless sensor network. The acquired data was processed to characterize the dynamics of the structure by means of two different output-only techniques, the frequency domain decomposition, and the stochastic subspace identification
Soil Displacement Estimation from Integrated Sensing Technologies in Data-Driven Models Biased by Temporal Coherence of PS-InSAR
No full textSpaceborne Synthetic Aperture Radar (SAR) interferometry provides long-term displacement measurements, but the quality of Persistent Scatterer (PS) time series depends critically on temporal coherence. Low-coherence points often exhibit auto-uncorrelated behaviours, which may be relevant to discriminate fast phenomena. This work introduces a coherence-based framework that identifies the coherence threshold beyond which PS displacement series retain sufficient reliability to support modelling. The threshold is estimated by analysing how data uncertainty, inferred through Sparse Bayesian Learning (SBL) techniques, varies with coherence and by detecting abrupt changes in this relationship. Once the optimal threshold is established, only the most reliable PS are used to train an SBL regression model linking satellite line-of-sight displacement to soil temperature and surface humidity measured by a low-cost ground sensor. PS-Interferometric SAR (PS-InSAR) time series are derived from COSMO-SkyMed raw images. The SBL model employs compressive-sensing principles and latent-parameter dictionaries of basis functions, whose latent parameters are calibrated through a constrained multi-start optimisation of a normalised residual-based objective function, regularised by a sub-validation dataset. In this work, it is shown that the trained model enables temporally denser reconstruction of displacement histories than the satellite revisit cycle allows and enables continuous soil monitoring by comparing model predictions with newly acquired PS-InSAR data
An implantable device for monitoring foetal lung pressure in an experimental model of congenital diaphragmatic hernia
No full textLAUREA MAGISTRALEL’ernia diaframmatica congenita (Congenital Diaphragmatic Hernia, CDH) consiste in un incompleto sviluppo fetale del diaframma e porta ad ipoplasia ed ipertensione polmonare del nascituro. Il corretto sviluppo polmonare può essere ripristinato mediante l’occlusione della trachea con l’inserzione in fetoscopia di un palloncino (Foetal Endoscopic Tracheal Occlusion, FETO) seguita da un secondo intervento di rimozione dopo 8 settimane. Alcuni studi hanno esplorato l’uso di materiali biodegradabili per l’occlusione al fine di evitare il secondo intervento, e l’uso di un’occlusione dinamica per promuovere l’efflusso di fluido polmonare. Uno studio pilota è stato condotto su modello animale di CDH all’University of Western Australia per testare l’efficacia della FETO con un nuovo idrogel sviluppato al Politecnico di Milano.
L’obiettivo di questa tesi è lo sviluppo di un dispositivo elettronico impiantabile low-power per monitorare la pressione media sviluppata nei polmoni durante il periodo di occlusione, e le oscillazioni pressorie dovute ai tentativi di respirazione fetale. Il dispositivo include una memoria flash per il salvataggio dei dati ed e un sistema di telemetria wireless via radio per permettere il monitoraggio in tempo reale durante lo sviluppo gestazionale. Il dispositivo è stato incapsulato in un involucro biocompatibile con dei cateteri per la misura della pressione, ed impiantato per 40 giorni nello studio pilota.
La comunicazione e il salvataggio dei dati hanno funzionato correttamente. Tuttavia, la durata della batteria è risultata minore di quella attesa, con una mediana di 15 giorni. Una revisione del dispositivo è stata proposta per migliorare il risparmio energetico. I dati raccolti hanno dimostrato la possibilità di monitorare la pressione e di identificare il respiro del feto, suggerendo revisioni del protocollo sperimentale. Test in vitro sul dispositivo revisionato hanno mostrato il superamento dei limiti riscontrati nello studio pilota. Esso verrà quindi utilizzato per uno studio di efficacia del nuovo trattamento FETO.Congenital Diaphragmatic Hernia (CDH) consists in an incomplete foetal development of the diaphragm during gestation, leading to pulmonary hypoplasia and hypertension at birth. A current prenatal management strategy to restore proper lung development is to occlude the foetal airway through the endoscopic insertion of a plastic balloon (Foetal Endoscopic Tracheal Occlusion, FETO) and reverse the occlusion by removing it with a second surgery after 8 weeks. Some studies explored the use of a biodegradable material as occluding device to avoid the second surgery and to promote lung fluid efflux by dynamic occlusion. A pilot study was carried out on an animal model of CDH at the University of Western Australia to test effectiveness of FETO procedures using a novel hydrogel developed at Politecnico di Milano.
The aim of this project is the design and development of an ultra-low power implantable device to monitor both the average pressure developed in the lung and the pressure oscillations due to foetal breathing efforts while the tracheal occlusion is in place. The device includes flash memory for data logging and a wireless RF telemetry system, allowing real-time monitoring during in-utero foetal development. The device was enclosed in a biocompatible case with catheters for pressure sensing, and implanted for 40 days during the pilot study.
Wireless communication and storage functionalities resulted to be effective. However, battery life was lower than expected, with a median duration of 15 days. A design revision was performed to improve power retention capability. The data collected during the device operative period proved the possibility to monitor pressure and identify foetal breathing. The provided data also allowed the re-design of the experimental protocol. The revised device was tested in vitro showing the successful overcome of the limitations identified during the pilot and will be used for a study on the efficacy of the new FETO treatment
A Simple Way to Apply Moisture Chamber Eyeglasses During Oculoplastic Surgery
No full textProper eyelid closure and a normal blink reflex are essential to maintain a stable tear film and a healthy corneal surface. We present a simple technique to apply moisture chamber eyeglasses after oculoplastic surgery. The Opti-Gard® protective eyewear is faster, easily applicable and well performing. It can be used with different face shape, and it does not require any additional trimming or modification. This technical note explains a very simple, economical and less time-consuming method to prevent a postoperative dry keratoconjunctivitis. It may be applied to all procedures within the field of ophthalmic surgery, including oculoplastic surgery.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Author
- …
