Risk Stratification in COVID-19 Pneumonia - Determining the Role of Lung Ultrasound.

LUS patterns of COVID-19 pneumonia have been described and shown to be characteristic. The aim of the study was to predict the prognosis of patients with COVID-19 pneumonia, using a score based on LUS findings. MATERIALS AND METHODS: An observational, retrospective study was conducted on patients admitted to Niguarda hospital with a diagnosis of COVID-19 pneumonia during the period of a month, from March 2nd to April 3rd 2020. Demographics, clinical, laboratory, and radiological findings were collected. LUS was performed in all patients. The chest was divided into 12 areas. The LUS report was drafted using a score from 0 to 3 with 0 corresponding to A pattern, 1 corresponding to well separated vertical artifacts (B lines), 2 corresponding to white lung and small consolidations, 3 corresponding to wide consolidations. The total score results from the sum of the scores for each area. The primary outcome was endotracheal intubation, no active further management, or death. The secondary outcome was discharge from the emergency room (ER). RESULTS: 255 patients were enrolled. 93.7 % had a positive LUS. ETI was performed in 43 patients, and 24 received a DNI order. The general mortality rate was 15.7 %. Male sex (OR 3.04, p = 0.014), cardiovascular disease and hypertension (OR 2.75, p = 0.006), P/F (OR 0.99, p < 0.001) and an LUS score > 20 (OR 2.52, p = 0.046) were independent risk factors associated with the primary outcome. Receiver operating characteristic (ROC) curve analysis for an LUS score > 20 was performed with an AUC of 0.837. Independent risk factors associated with the secondary outcome were age (OR 0.96, p = 0.073), BMI (OR 0.87, p = 0,13), P/F (OR 1.03, p < 0.001), and LUS score < 10 (OR 20.9, p = 0.006). ROC curve analysis was performed using an LUS score < 10 with an AUC 0.967. CONCLUSION: The extent of lung abnormalities evaluated by LUS score is a predictor of a worse outcome, ETI, or death. Moreover, the LUS score could be an additional tool for the safe discharge of patient from the ER.

Methane Gas Photonic Sensor Based on Resonant Coupled Cavities.

In this paper we report methane gas photonic sensors exploiting the principle of absorption-induced redirection of light propagation in coupled resonant cavities. In particular, an example of implemented architecture consists of a Fabry-Pérot (FP) resonator coupled to a fibre ring resonator, operating in the near IR. By changing the concentration of the methane gas in the FP region, the absorption coefficient of the FP changes. In turn, the variation of the methane gas concentration allows the redirection of the light propagation in the fibre ring resonator. Then, the methane gas concentration can be evaluated by analysing the ratio between the powers of two resonant modes, counter-propagating in the fibre ring resonator. In this way, a self-referenced read-out scheme, immune to the power fluctuations of the source, has been conceived. Moreover, a sensitivity of 0.37 ± 0.04 [dB/%], defined as the ratio between resonant modes at different outputs, in a range of methane concentration included between the 0% and 5%, has been achieved. These results allow a detection limit below the lower explosive limit (LEL) to be reached with a cost-effective sensor system.

Fibre Bragg Grating Based Strain Sensors: Review of Technology and Applications.

Fibre Bragg grating (FBG) strain sensors are not only a very well-established research field, but they are also acquiring a bigger market share due to their sensitivity and low costs. In this paper we review FBG strain sensors with high focus on the underlying physical principles, the interrogation, and the read-out techniques. Particular emphasis is given to recent advances in highly-performing, single head FBG, a category FBG strain sensors belong to. Different sensing schemes are described, including FBG strain sensors based on mode splitting. Their operation principle and performance are reported and compared with the conventional architectures. In conclusion, some advanced applications and key sectors the global fibre-optic strain sensors market are envisaged, as well as the main market players acting in this field.

Therapeutic Approach to Hypertension Urgencies and Emergencies in the Emergency Room.

Hypertensive urgencies-emergencies are important and common events. They are defined as a severe elevation in BP, higher than 180/120 mmHg, associated or not with the evidence of new or worsening organ damage for emergencies and urgencies respectively. Anamnestic information, physical examination and instrumental evaluation determine the following management that could need oral (for urgencies) or intravenous (for emergencies) anti-hypertensives drugs. The choice of the specific drugs depend on the underlying causes of the crisis, patient's demographics, cardiovascular risk and comorbidities. For emergencies a maximum BP reduction of 20-25% within the first hour and then to 160/110-100 over next 2-6 h, is considered appropriate with a further gradual decrease over the next 24-48 h to reach normal BP levels. In the case of hypertensive urgencies, a gradual lowering of BP over 24-48 h with an oral medication is the best approach and an aggressive BP lowering should be avoided. Subsequent management with particular attention on chronic BP values control is important as the right treatment of the acute phase.

Gyroscope Technology and Applications: A Review in the Industrial Perspective.

This paper is an overview of current gyroscopes and their roles based on their applications. The considered gyroscopes include mechanical gyroscopes and optical gyroscopes at macro- and micro-scale. Particularly, gyroscope technologies commercially available, such as Mechanical Gyroscopes, silicon MEMS Gyroscopes, Ring Laser Gyroscopes (RLGs) and Fiber-Optic Gyroscopes (FOGs), are discussed. The main features of these gyroscopes and their technologies are linked to their performance.

Lung ultrasound for monitoring cardiogenic pulmonary edema.

Several studies address the accuracy of lung ultrasound (LUS) in the diagnosis of cardiogenic pulmonary edema (CPE) evaluating the interstitial syndrome, which is characterized by multiple and diffuse vertical artifacts (B-lines), and correlates with extravascular lung water. We studied the potential role of LUS in monitoring CPE response to therapy, by evaluating the clearance of interstitial syndrome within the first 24 h after Emergency Department (ED) admission. LUS was performed at arrival (T0), after 3 (T3) and 24 (T24) hours. Eleven regions were evaluated in the antero-lateral chest; the B-lines burden was estimated in each region (0 = no B-lines, 1 = multiple B-lines, 2 = confluent B-lines/white lung) and a mean score (B-Score, range 0-2) was calculated. Patients received conventional CPE treatment. Blood chemistry, vital signs, blood gas analysis, diuresis at T0, T3, T24 were also recorded. A complete echocardiography was obtained during hospitalization. Forty-one patients were enrolled. Respiratory and hemodynamic parameters improved in all patients between T0 and T3 and between T3 and T24. Mean B-score significantly decreased at T3 (from 1.59 ± 0.40 to 0.73 ± 0.44, P < 0.001) and between T3 and T 24 (from 0.73 ± 0.44 to 0.38 ± 0.33, P < 0.001). B-score was higher in the lower pulmonary regions at any time. At final evaluation (T24) 75 % of apical and only 38 % of basal regions were cleared. LUS allows one to assess the clearance of interstitial syndrome and its distribution in the early hours of treatment of CPE, thus representing a possible tool to guide therapy titration.

Investigation of refractive index sensing based on Fano resonance in fiber Bragg grating ring resonators.

In this paper we theoretically investigate a ring resonant cavity obtained by closing on itself a π-shifted fiber Bragg grating, to be used for refractive index sensing applications. Differently from a conventional π-shifted fiber Bragg grating, the spectral structure of this cavity is characterized by an asymmetric splitting doublet composed by a right side resonance having an asymmetric Fano profile and a left side resonance having a symmetric Lorentzian profile. The right side resonance shows a narrower and sharper peak than all the other kinds of resonance achievable with both conventional ring resonators and π-shifted fiber Bragg gratings. A reduction of the resonant linewidth with respect to a conventional π-shifted Fiber Bragg grating and a fiber ring resonator, having the same physical parameters, is theoretically proved, achieving up to five orders of magnitude improvement with respect to the usual ring resonator. Due to these resonance features, the π-shifted Bragg grating ring resonator results suitable for RI sensing applications requiring extremely narrow resonances for high resolution measurements. In particular, by assuming a refractive index sensing to detect the presence of sugar in water, the sensor can show a theoretical resolution better than 10-9 RIU.

Investigation of fiber Bragg grating based mode-splitting resonant sensors.

In this paper, we report on theoretical investigation of split mode resonant sensors based on fiber Bragg grating (FBG) ring resonators and π-shifted fiber Bragg grating (π-FBG) ring resonators. By using a π-shifted Bragg grating ring resonator (π-FBGRR) instead of a conventional fiber Bragg grating ring resonator (FBGRR), the symmetric and antisymmetric resonance branches (i.e., the eigen-modes of the perturbed system) show peculiar and very important features that can be exploited to improve the performance of the fiber optic spectroscopic sensors. In particular, the π-FBGRR symmetric resonance branch can be taylored to have a maximum splitting sensitivity to small environmental perturbations. This optimal condition has been found around the crossing points of the two asymmetric resonance branches, by properly choosing the physical parameters of the system. Then, high sensitivity splitting mode sensors are theoretically demonstrated showing, as an example, a strain sensitivity improvement of at least one order of magnitude over the state-of-the-art.

Performance of SOI Bragg grating ring resonator for nonlinear sensing applications.

In this paper, a spectroscopic sensor formed by a silicon-on-insulator waveguiding Bragg grating ring resonator working in linear and non-linear regime is proposed. In linear regime, the device shows a spectral response characterized by a photonic band gap (PBG). Very close to the band gap edges, the resonant structure exhibits split modes having a splitting magnitude equal to the PBG spectral extension, whose characteristics can be exploited to obtain a RI optical sensor almost insensitive to the fabrication tolerances and environmental perturbations. When the device operates in nonlinear regime, exactly in the spectral region showing the split resonant modes, the RI sensing performance is strongly improved with respect to the linear regime. This improvement, demonstrated by taking into account all the non-linear effects excited in the integrated silicon structure (i.e., Two Photon Absorption (TPA), TPA-induced Free Carrier Absorption, plasma dispersion, Self-Phase-Modulation and Cross-Phase-Modulation effects as induced by Kerr nonlinearity) as well as the deleterious thermal and stress effects, allows enhancing the performance of the RI split mode resonant sensors, while achieving good immunity to the fabrication tolerances and environmental perturbations. The improvement in terms of sensor resolution can be at least one order of magnitude, still without using optimal parameters.

Recent advances in gas and chemical detection by Vernier effect-based photonic sensors.

Recently, the Vernier effect has been proved to be very efficient for significantly improving the sensitivity and the limit of detection (LOD) of chemical, biochemical and gas photonic sensors. In this paper a review of compact and efficient photonic sensors based on the Vernier effect is presented. The most relevant results of several theoretical and experimental works are reported, and the theoretical model of the typical Vernier effect-based sensor is discussed as well. In particular, sensitivity up to 460 µm/RIU has been experimentally reported, while ultra-high sensitivity of 2,500 µm/RIU and ultra-low LOD of 8.79 × 10(-8) RIU have been theoretically demonstrated, employing a Mach-Zehnder Interferometer (MZI) as sensing device instead of an add drop ring resonator.