Non-invasive hemodynamic monitoring techniques for detecting Preload responsiveness in critically ill patients

Volume expansion is the first-line treatment for acute circulatory failure in almost all cases. However, its inconsistent effectiveness and its side effects make it necessary to predict the effects before undertaking it. Several tests have been developed to detect this state of preload dependence, and we are interested in refining some of them and improve their use. The end expiratory occlusion (EEXPO) test consists in transiently stopping mechanical ventilation at end expiration to increase venous return and, thus, cardiac preload. In preload responder patients it is expected to increase cardiac output. We have gathered an amount of information from the existing literature, showing that its ability of detecting fluid responsiveness is very high, through a systematic review and meta-analysis. The effects of this test must be assessed on cardiac output, and several methods have already been described for this. Bioreactance is a completely non invasive technique to measure cardiac output, which has been demonstrated to be reliable in detecting preload responsiveness through a passive leg raising (PLR) maneuver. Nevertheless, its role in detecting a positive EEXPO test was never investigated. In the main study of this PhD project, we show that the current available commercial version of the bioreactance device is not suitable for this purpose, due to its very long averaging and refreshing times (24 and 4 seconds, respectively). However, when we used a research version of the device, which allowed us to reduce both intervals (8 and 1 second for averaging and refreshing times, respectively), bioreactance proved to be a reliable method to detect preload responsiveness through the EEXPO test. We have also described an original and reliable method for measuring the effects of both PLR and EEXPO tests, which consists of measuring the perfusion index (PI), the ratio between the pulsatile and the non-pulsatile portion of the pulse oxygen saturation signal. Although the signal could not be collected stably in all patients, changes in this index during passive leg raising were able to measure the effects of the PLR test and predict the response to volume expansion. Similarly, Pl measurements could identify a positive EEXPO test, even though their changes were of lower amplitude compared to those of a PLR test. Our results open up the possibility of measuring the effects of these tests of preload responsiveness using non-invasive tools. This could prompt their use outside the intensive care unit, such as in the emergency department, where tracking changes of cardiac output during the first hours of the management of acute circulatory failure could lead to a more rational use of fluid administration

Cainà: Islandscape and ‘islanderscope’ on screen

The establishment of Island Studies within the academe and the introduction of concepts such as ‘islandness’ and ‘islandscape’ have accompanied a general rethinking of the concept of insularity which encompasses the reflection over a cinematic representation of islands and islanders. The use of islands as cinematic landscapes and settings has reinforced cultural, mythical, and identity stereotypes associated with the island imagery built-up in literature, as well as the construction of the islander as a character exhibiting specific behavioural features. The film Cainà. L’isola e il continente (Gennaro Righelli, 1922) is emblematic insofar as it is the first feature film shot in Sardinia and its character is not just a symbol of feminine rebellion against a patriarchal society, but it also serves as an allegory of an unspoiled island, such as it was considered and depicted at that time. As islanders ourselves, we have wondered to what extent Cainà adheres to the stereotypes of islandness and insularity conventionally ascribed to islands and, in this specific case, to Sardinia. Our paper aims to examine the genesis of the Sardinian insular imagination through the lens of the cinematic construction of ‘islanderness’ and ‘islanderscope’, an assortment of agency representing islanders — and islands — on screen

Bleeding Pseudocyst of the Pancreatic Head. The role of Omentoplasty and Local Hemostasis

Treatment of bleeding psedoaneurysms and pseudocysts of the pancreas is controversial. Surgical treatment with pancreatic resection or trancystic arterial ligation is not always satisfactory since postoperative mortality rate is high, especially for lesions located in the pancreatic head and rebleeding is not unusual. Two patients with bleeding pseudoaneurysms (one post traumatic, one spontaneous) and one with a hemorrhagic pseudocyst of the pancreatic head were treated surgically with arterial suture and omentoplasty. Bleeding was controlled in all, without any postoperative mortality or morbidity. No rebleeding occurred with a follow up of 33, 26 and 12 months. Trancystic ligation of bleeding vessels with omentoplasty may be a useful approach, which should be compared to arterial embolization in the future

CT perfusion in patients with lung cancer: Squamous cell Carcinoma and Adenocarcinoma show a different Blood Flow

Objectives. To characterize tumour baseline blood flow (BF) in two lung cancer subtypes, adenocarcinoma (AC) and squamous cell carcinoma (SCC), also investigating those \u201cborderline\u201d cases whose perfusion value is closer to the group mean of the other histotype. Materials and Methods. 26 patients (age range 36-81 years) with primary Non-Small Cell Lung Cancer (NSCLC), subdivided into 19 AC and 7 SCC, were enrolled in this study and underwent a CT perfusion, at diagnosis. BF values were computed according to the maximum-slope method and unreliable values (e.g., arising from artefacts or vessels) were automatically removed. The one-tail Welch\u2019s t-test (p-value < 0.05) was employed for statistical assessment. Results. At diagnosis, mean BF values (in [mL/min/100g]) of AC group [(83.5 \ub1 29.4)] are significantly greater than those of SCC subtype [(57.0 \ub1 27.2)] (p-value = 0.02). However, two central SCCs undergoing artefacts from vena cava and pulmonary artery have an artificially increased mean BF. Conclusions. The different hemodynamic behaviour of AC and SCC should be considered as a biomarker supporting treatment planning to select the patients, mainly with AC, that would most benefit from antiangiogenic therapies. The significance of results was achieved by automatically detecting and excluding artefactual BF values

Funzioni a Variazione limitata e insiemi di Perimetro minimo

Questa Tesi si propone di trattare parte della teoria di tali Spazi BV, seguendo principalmente la presentazione di Evans e Gariepy, per poi arrivare nell’ultimo capitolo dimostrare un Teorema di esistenza di insiemi di perimetro minimo, date determinate condizioni al contorno. Per quest'ultimo risultato si fa riferimento a Giusti. Nel primo capitolo si introducono gli Spazi BV e viene data una definizione di insiemi di perimetro finito. Si dimostra il Teorema di Struttura che garantisce che le derivate in senso distribuzionale delle funzioni f in BV sono misure di Radon, per poi dare a BV una struttura di Spazio normato. Il capitolo si conclude con un confronto tra gli Spazi BV e gli Spazi di Sobolev. Il capitolo 2 inizia con la dimostrazione della semicontinuità inferiore della misura variazione. All'interno di questo capitolo si dimostra anche il Teorema di Anzellotti-Giaquinta, una generalizzazione del Teorema di Meyers-Serryn nello Spazio delle funzioni BV che permette di approssimare ogni funzione a variazione limitata tramite funzioni lisce. Il terzo capitolo è interamente dedicato allo studio del funzionale di "Traccia", utile per controllare il "comportamento al bordo" per funzioni con una certa regolarità fino alla frontiera dell'insieme in cui sono supportate. Nel quarto capitolo vengono generalizzate le disuguaglianze di Sobolev e Poincaré alle funzioni BV. Fatto ciò, vengono dimostrate la disuguaglianza isoperimetrica e una sua versione locale. Nel quinto ed ultimo capitolo infine si vuole dare un esempio di problema che è stato risolto grazie all'introduzione degli Spazi BV. Il problema è quello di mostrare l'esistenza e l'unicità di un insieme di perimetro minimo tra un insieme di insiemi che rispettino una stessa condizione al contorno. Per fare ciò si sfrutta un metodo diretto del calcolo delle variazioni che si avvale principalmente dei risultati di semicontinuità inferiore e di Compattezza mostrati nel capitolo 2

Image-processing assisted characterization of spray injection systems

The objective of this work is to investigate the spray characteristics of a fuel injection nozzle. The analysis is performed by means of a framework which exploits different image processing techniques to provide spray-related data to the operator. Innovative metrics are introduced to increase the accuracy and efficiency of the scheme. Experimental results show that it is possible to automatically get useful information about the spray distribution, asymmetries and key properties together with the capability to measure significant angles and other information to detect anomalies in the injection system

A drone-based image processing system for car detection in a smart transport infrastructure

In this paper we present a car detection system prototyped within an experimental project. It analyzes video streams recorded by drones flying over an urban environment. The intended final goal is the automatic provision of helpful information, such as the available parking spaces and the level of congestion of the streets. The system has been tested both in a desktop PC and on an embedded system. The experimental results show a significant accuracy and prove the feasibility of novel on-board services

The Primacy of High b-Value 3T-DWI Radiomics in the Prediction of Clinically Significant Prostate Cancer

Predicting clinically significant prostate cancer (csPCa) is crucial in PCa management. 3T-magnetic resonance (MR) systems may have a novel role in quantitative imaging and early csPCa prediction, accordingly. In this study, we develop a radiomic model for predicting csPCa based solely on native b2000 diffusion weighted imaging (DWIb2000) and debate the effectiveness of apparent diffusion coefficient (ADC) in the same task. In total, 105 patients were retrospectively enrolled between January–November 2020, with confirmed csPCa or ncsPCa based on biopsy. DWIb2000 and ADC images acquired with a 3T-MRI were analyzed by computing 84 local first-order radiomic features (RFs). Two predictive models were built based on DWIb2000 and ADC, separately. Relevant RFs were selected through LASSO, a support vector machine (SVM) classifier was trained using repeated 3-fold cross validation (CV) and validated on a holdout set. The SVM models rely on a single couple of uncorrelated RFs (ρ < 0.15) selected through Wilcoxon rank-sum test (p ≤ 0.05) with Holm–Bonferroni correction. On the holdout set, while the ADC model yielded AUC = 0.76 (95% CI, 0.63–0.96), the DWIb2000 model reached AUC = 0.84 (95% CI, 0.63–0.90), with specificity = 75%, sensitivity = 90%, and informedness = 0.65. This study establishes the primary role of 3T-DWIb2000 in PCa quantitative analyses, whilst ADC can remain the leading sequence for detection

A sensor aided H.264 encoder tested on aerial imagery for SFM

Email Print Request Permissions Standard video coding systems currently employed in UAV (Unmanned Aerial Vehicle) and aerial drone applications do not rely on some peculiarities in terms of scene 3D model and correlation among successive frames. In particular, the observed scene is static, i.e. the camera movement is dominant, and it can often be well approximated with a plane. Moreover, camera position and orientation can be obtained from the navigation system. Therefore, correspondent points on two video frames are linked by a simple homography. This paper presents novel results obtained by a low-complexity sensor aided H.264 encoder, recently developed at CIRA and yet tested on simulated data. The proposed encoder employs a new motion estimation scheme which make use of the global motion information provided by the onboard navigation system. The homography is used in order to initialize the block matching algorithm allowing a more robust motion estimation and a smaller search window, and hence reducing the complexity. The tests are made coding real aerial imagery, captured to be used for 3D scene reconstruction. The images are acquired by an high resolution camera mounted on a small drone, flying at low altitude