Search Results (318)

This study presents the design and validation of an integrated fire safety system that leverages edge AI, hybrid sensing, and precision suppression to overcome the latency and collateral limitations of conventional smoke detection and sprinkler systems. The proposed platform features a dual-mode sensor array for early fire recognition, motorized ventilation units for rapid smoke extraction, and a 360° directional nozzle for targeted agent discharge using a residue-free clean extinguishing agent. Experimental trials demonstrated an average fire detection time of 5.8 s and complete flame suppression within 13.2 s, with 90% smoke clearance achieved in under 95 s. No false positives were recorded during non-fire simulations, and the system remained fully functional under simulated cloud communication failure, confirming its edge-resilient architecture. A probabilistic risk analysis based on ISO 31000 and NFPA 551 frameworks showed risk reductions of 75.6% in life safety, 58.0% in property damage, and 67.1% in business disruption. The system achieved a composite risk reduction of approximately 73%, shifting the operational risk level into the ALARP region. These findings demonstrate the system’s capacity to provide proactive, energy-efficient, and spatially targeted fire response suitable for high-value infrastructure. The modular design and SmartThings Edge integration further support scalable deployment and real-time system intelligence, establishing a strong foundation for future adaptive fire protection frameworks. Full article

The optimization of ventilation strategies in high-ceiling theater stage spaces is crucial for improving thermal comfort and energy efficiency. This study addresses the challenge of uneven temperature distribution and airflow stagnation in stage environments by employing computational fluid dynamics (CFD) simulations to evaluate the effectiveness of different ventilation modes, including natural, mechanical, and hybrid systems. Six airflow organization scenarios were designed based on modifications to structural layout, equipment settings, and mechanical disturbances (e.g., fan integration). Key evaluation indicators such as temperature uniformity coefficient, airflow velocity, and exhaust efficiency were used to assess performance. The results show that a multi-dimensional optimization approach combining spatial adjustments and mechanical disturbances significantly reduced the average temperature from 26 °C to 23 °C and the temperature uniformity coefficient from 2.79 to 1.49. This study contributes a comprehensive design strategy for stage ventilation that improves comfort while minimizing energy consumption, offering practical implications for performance space design and HVAC system integration. Full article

Respiratory muscle training (RMT) has been proposed as a supportive strategy for adults receiving invasive mechanical ventilation; however, the way RMT is prescribed—mode, intensity, frequency, and volume—remains highly heterogeneous. Objectives: This study aimed to describe the current evidence regarding the prescription of respiratory muscle strengthening in terms of frequency, intensity, method, and volume in adult patients under mechanical ventilation in intensive care units. Methods: A scoping review was conducted following the PRISMA-ScR guidelines based on searches in electronic databases including Scopus, SciELO, ScienceDirect, PubMed, LILACS, Springer, Web of Science, Google Scholar, PEDro, Dialnet, and Cochrane. Results: Seven studies met the established inclusion criteria and described prescription protocols for respiratory muscle strengthening in adult patients under mechanical ventilation in intensive care units. Conclusions: The most frequently reported protocol involved threshold load training at 40–50% of maximal inspiratory pressure, administered twice daily, every day of the week, with a volume of 30 repetitions. This intervention showed promising results in improving inspiratory muscle strength, with potential additional benefits in weaning success and pulmonary function. Full article

In practice, many patients receive APAP treatment for the simple reason that it provides increased comfort and is easier for patients to accept and tolerate. Reality has proven that we have very many patients diagnosed with OSAS on APAP treatment, under which AHI has normalized, but patients continue to have remaining symptoms. Thus the question was born: is the persistence of remnant symptomatology under APAP related to the mode of ventilation in patients with normalized AHI? The target group was young obese men presenting to the urology service for nocturnal pollakiuria without urologic cause. After performing nocturnal ventilatory polygraphy, the patients were recommended APAP treatment for three months, subsequently, the patients were switched to CPAP treatment for another three months, thus comparing the results obtained. After 6 months of treatment, 71.4% of the subjects would opt to continue CPAP treatment. While a clear option for APAP treatment was expressed by 10.2%. Our research, suggests that we should not be misled by the normalization of AHI under APAP therapy, but to evaluate the patients also with the help of available and standardized questionnaires. Full article

Background/Objectives: Neonatal and infant respiratory distress carries high morbidity, and severity can vary with gestational maturity and perinatal factors. Early risk stratification may improve outcomes, but existing assessment tools do not fully address age-related risk differences. We aimed to develop and validate a Neonatal Clinical Risk Assessment Score (N-CRAS) for predicting severity in neonates and young infants with respiratory distress due to respiratory infection. Methods: This pilot score was applied exclusively to a cohort of forty neonates and young infants with respiratory distress secondary to infectious causes, as defined by clinical and laboratory parameters. Clinical variables (gestational age, delivery mode, birth weight category, and APGAR score) were recorded and analyzed for associations with illness severity. We developed the N-CRAS (0–5 points) encompassing five indicators of severe illness (respiratory infection, metabolic disorder, need for symptomatic treatment, mechanical ventilation, and intubation), each contributing 1 point. Patients were stratified as low (0–1), moderate (2–3), or high (4–5) risk. Chi-square tests and Spearman correlation assessed associations, and an ROC curve evaluated the score’s predictive performance for intubation. Results: No individual perinatal factor was significantly associated with respiratory illness severity. The N-CRAS increased with infant age (p < 0.05), indicating older infants tended to have more severe disease. All study infants who required intubation fell into the high-risk category (score ≥ 4). The N-CRAS demonstrated excellent discrimination for predicting intubation (ROC area under the curve = 1.00). Conclusions: In this pilot study, the N-CRAS demonstrated a strong correlation with clinical severity and successfully identified all infants who required intubation. However, given the small cohort size and limited number of severe cases, these findings should be interpreted cautiously. Further external validation in larger and more diverse neonatal populations is essential to confirm its predictive utility. Full article

Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species, and Candida species are common ventilator-associated pneumonia (VAP) isolates. Whilst the clinical significance of Candida as a VAP isolate is unclear, evidence is emerging that Candida interacts with bacteria, contributing to colonization susceptibility. Indirectly, VAP isolate data reflect patient colonization within cohorts. The objective here is to estimate the association between these three bacteria and Candida as VAP isolates. ICU cohorts were obtained by searching the literature for mechanically ventilated (MV) patient cohorts in which Candida was listed as an isolate among patients with VAP. Regression models of the associated VAP incidence per 100 MV patients, using random effects methods, incorporated group-level factors such as the year of publication, mode of VAP diagnosis, and ICU stay length. The median VAP incidence proportions for Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter species were 3.3 (IQR: 1.2–6.9), 3.6 (IQR: 1.8–5.7), and 1.2 (IQR: 0.4–4.1), respectively. Among 84 cohorts from 67 publications, Staphylococcus aureus (correlation coefficient = 0.759) and Pseudomonas aeruginosa (0.749), and less so Acinetobacter species (0.53), each show correlation with the isolation of Candida species among these ICU populations. These associations may underlie the poor prognosis with Candida colonization. Full article

Condensation assessment of a residential building in Changsha, China-located in the hot summer and cold winter climate zone-was conducted during the Plum Rain Season (PRS) using Energy Plus simulations and field measurements. Window-opening behaviour significantly influences indoor air quality and thermal comfort. This study specifically examines how window-opening patterns, including opening duration and opening degree, affect interior surface condensation risk in a rural residential building during PRS. Results indicate that window operational status (open/closed) exerts a dominant influence on condensation risk, while varying window opening degrees during identical opening duration showed negligible differential impacts. Critical temporal patterns emerged: morning window openings during PRS should be avoided, whereas afternoon (15:00–18:00) and nighttime (18:00–06:00) ventilation proves advantageous. Optimisation analysis revealed that implementing combined afternoon and nighttime ventilation windows (15:00–18:00 + 18:00–06:00) achieved the lowest condensation risk of 0.112 among evaluated scenarios. Furthermore, monthly-adjusted window operation strategies yielded eight recommended ventilation modes, maintaining condensation risks below 0.11 and providing occupant-tailored solutions for Changsha’s PRS conditions. These findings establish evidence-based guidelines for moisture control through optimised window operation in climate-responsive building management. Full article

Ventilation systems are susceptible to errors, external disruptions, and nonlinear dynamics. Maintaining stable operation and regulating these dynamics require an efficient control system. This study focuses on the speed control of ventilation systems using a super twisted sliding mode observer (STSMO), which provides robust and efficient state estimation for sensorless control. Traditional SM control methods are resistant to parameter fluctuations and external disturbances but are affected by chattering, which degrades performance and can cause mechanical wear. The STSMO leverages the super twisted algorithm, a second-order SM technique, to minimize chattering while ensuring finite-time convergence and high resilience. In sensorless setups, rotor speed and flux cannot be measured directly, making their accurate estimation crucial for effective ventilation drive control. The STSMO enables real-time control by providing current and voltage estimations. It delivers precise rotor flux and speed estimations across varying motor specifications and load conditions using continuous control rules and observer-based techniques. This paper outlines the mathematical formulation of the STSMO, highlighting its noise resistance, chattering reduction, and rapid convergence. Simulation and experimental findings confirm that the proposed observer enhances sensorless ventilation performance, making it ideal for industrial applications requiring reliability, cost-effectiveness, and accuracy. Full article

The environment inside subway carriages is relatively enclosed, putting passengers at risk of respiratory infections during viral pandemics such as COVID-19 and SARS. This paper uses the Euler–Lagrange method to simulate the distribution of droplet nuclei produced by coughing under six different operating conditions in a subway carriage. The study investigates the impact of different air supply characteristics and ventilation methods, including mixed ventilation (MV), floor-supply, and ceiling-return ventilation (SFRC), on the distribution of droplets. These results indicate that under MV mode, the dispersion range of droplets during a patient’s cough is the largest, with an average droplet suspension rate (SR) of up to 77% at the initial moment. The SFRC system markedly diminishes droplet dispersion, decreasing the SR by 35%. Upon increasing the air supply velocity to 0.8 m/s, the SR diminishes to 6%, the probability of particles attaining a 2 m social distance (PRP) declines by roughly 70%, and the weighted average contamination range (CR) of coughing particles reaching a safe social distance reduces by 33.5%. These results may act as a guide for the subsequent design and optimization of airflow patterns in carriages to reduce the risk of cross-infection. Full article

Background and Objectives: Chronic obstructive pulmonary disease (COPD) poses a significant healthcare challenge worldwide, frequently leading to exacerbations necessitating intensive care unit admissions for potentially life-threatening complications. We aimed to investigate correlations between laboratory parameters, bacteriological agents, ventilation mode, and survival rates among COPD patients admitted to the ICU. Materials and Methods: Data were collected from the Pulmonology Department of Mures Clinical County Hospital, Romania, from 1 January 2022 to 30 October 2023. Eighty-four COPD patients required ICU transfer, except for concurrent SARS-CoV-2 infections. Results: Ventilation modes exhibited a significant correlation with specific bacteriological agents, orotracheal intubation being more prevalent in infections with Acinetobacter baumanii, Staphylococcus aureus, and Streptococcus pneumoniae (p < 0.001). Negative cultures were predominantly found in patients managed with non-invasive ventilation. Laboratory parameters revealed an association between elevated white blood cell counts and bacteriological superinfection, particularly with Escherichia coli (p < 0.001). Different bacteriological agents had different survival rates. Patients infected with Acinetobacter baumanii exhibited the highest mortality rate, while those with Staphylococcus aureus had the lowest (p < 0.01). Conclusions: The importance of prompt evaluation of laboratory parameters and bacteriological findings is underscored by these findings, particularly in ICU settings where ventilation and bacteriological profiles influence patient outcomes. The identification of elevated WBC counts is a marker of bacterial superinfection. The association between specific bacterial agents and ventilation modes highlights the importance of tailored treatment based on microbial profiles. These insights can be applied to refine treatment protocols and enhance survival rates in severe COPD exacerbations that require ICU management. Full article

Background/Objectives: Surgical procedures in chronic obstructive pulmonary disease (COPD) patients carry a high risk of postoperative respiratory failure, often causing the need for mechanical ventilation and prolonged intensive care unit (ICU) stays. Accompanying COPD with heart failure further increases the risk of complications. This study aimed to identify predictors of mortality, prolonged ICU and hospital stays, the need for mechanical ventilation, and vasoactive drug usage in ICU patients with moderate to severe COPD undergoing elective non-cardiac surgery. Methods: This retrospective cohort study analyzed eICU-CRD data, including adult patients with moderate to severe COPD admitted to the ICU from the operating room following elective non-cardiac surgery. Spearman’s correlation analysis was performed to assess associations between intraoperative ventilation parameters and ICU/hospital length of stay, postoperative laboratory parameters, and their perioperative dynamics. Results: This study included 680 patients (21% with severe COPD). Hospital and ICU mortality were 8.6% and 4.4%, respectively. Median ICU and hospital stays were 1.9 and 6.6 days, respectively. Intraoperative tidal volume, expired minute ventilation, positive end-expiratory pressure, mean airway pressure, peak inspiratory pressure, and compliance had no statistically significant association with mortality, postoperative mechanical ventilation, its duration, or the use of vasopressors/inotropes. Tidal volume correlated positively with changes in monocyte count (R = 0.611; p = 0.016), postoperative lymphocytes (R = 0.327; p = 0.017), and neutrophil count (R = 0.332; p = 0.02). Plateau pressure showed a strong positive association with the neutrophil-to-lymphocyte ratio (R = 0.708; p = 0.001). Conclusions: Intraoperative ventilation modes and parameters in COPD patients appear to have no significant impact on the outcomes or laboratory markers, except possibly for the neutrophil-to-lymphocyte ratio, although its elevation cause remains unclear. Full article

Ice accumulation on heating, ventilation, air conditioning, and refrigeration (HVACR) structures presents significant operational challenges. These challenges include reduced efficiency, increased energy consumption, and potential damage to equipment. Traditional de-icing methods, such as chemical treatments, mechanical scraping, or heating-based techniques, are often labor-intensive, costly, and environmentally harmful. This study uniquely investigates ultrasonic de-icing as an energy-efficient alternative for HVACR applications, focusing on the specific structural geometries found in these systems. A comprehensive numerical simulation framework was developed using finite element analysis to explore ultrasonic wave propagation across four distinct HVACR structures. Key parameters such as ultrasonic frequency, power levels, and the number and placement of actuators were examined for their impact on ice detachment efficiency. Results from simulations on a plate structure reveal that ultrasonic excitation can propagate effectively across large areas (at least 150 × 150 mm), enhancing the de-icing coverage. Lower frequency (e.g., 30 to 45 kHz) excitation results in greater displacement, improving de-icing performance, while increased actuator numbers with the same total power input also enhance effectiveness. Two actuators seem sufficient for the de-icing of a 300 × 300 mm plate. For tube-and-fin structures, specific high-power ultrasonic frequencies selectively excite the fin plates, demonstrating efficient ice removal when actuated on the tube. However, optimal performance requires careful design of actuator placement and vibration modes to accommodate the irregular shapes of these structures. Full article

Background/Objectives: The coronavirus disease (COVID-19) pandemic was associated with an intense impact on health worldwide. Among the sequelae, it became necessary to clarify respiratory impairment related to lung function and aerobic capacity, as well as the treatment of curative and preventive measures of pulmonary involvement. In this context, this study aimed to compare vital signs, the sensation of dyspnea (Borg scale), lung function, and exercise tolerance before and after the use of non-invasive mechanical ventilation (NIV) in adults of both sexes after acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: A cross-sectional analytical clinical study was performed with the inclusion of individuals who had been diagnosed with COVID-19 at least three months before data collection. Individuals were evaluated for vital signs (heart rate and peripheral oxygen saturation), Borg scale, spirometry, and submaximal exercise protocol of two minutes of the step test before and after receiving NIV in ventilation mode by continuous positive airway pressure of 6 cm H₂O for 30 min. Results: A total of 50 participants were enrolled and grouped as a mild (N = 25) or severe (N = 25) clinical phenotype during SARS-CoV-2 infection according to the criteria of the World Health Organization. In our data, the forced vital capacity (p < 0.001), the ratio between the forced expiratory volume in the first one second to the forced vital capacity and the forced vital capacity (p = 0.020), and the two-minute submaximal step exercise protocol (number of steps—p = 0.001) showed a statistical improvement in the severe clinical phenotype group after NIV. In addition, forced expiratory volume in the first one second to the forced vital capacity (p = 0.032) and the two-minute submaximal step exercise protocol (number of steps—p < 0.001) showed a statistical improvement in the mild clinical phenotype group after NIV. No changes were described for vital signs and the Borg scale. Conclusions: This study allowed us to identify that NIV is a tool that promotes better exercise capacity by increasing the number of steps achieved in both clinical phenotype groups and improving lung function observed in the spirometry markers. Full article

Thermal comfort is not a luxury; rather, a lack of it is a matter of life and death, particularly for vulnerable people, such as older people. This work systematically reviews and analyses the thermal comfort of older people and their health and mortality as it relates to exposure to extreme temperatures, and suggests acceptable thermal conditions and the related energy use of buildings. A total of 69 out of 198 papers were found on older people and these were analysed in detail. This was followed by an analysis of the UN and UK governments’ open access data. This work highlights the disparity regarding the definition of age for older people and encourages the use of the term ”older people”, rather than ”elderly”, which can be an offensive piece of terminology. The UK findings suggest a significant relationship between cold (below 5 °C) outdoor air temperatures and mortality in older people, particularly for those who are over 85 years old. In the UK, thermal conditions can lead to up to 175 deaths per degree temperature change up to two weeks after a cold spell or an overly hot period. The indoor comfort temperature of older people varies between 22.5 and 27 °C in natural ventilation mode. However, some studies found 18 °C to be comfortable in winter time, a finding which could lead to a significant energy saving in relation to space heating. Current gaps in and the recommended future direction of research include topics such as gender differences in terms of thermal comfort and during menopause; thermal comfort conditions, adaptive behaviours and naturally ventilated buildings; thermal conditions when sleeping and energy use as it relates to space heating or cooling for older people. Full article

Background/Objectives: The aim of this study was to determine the optimal ventilation mode during cardiopulmonary resuscitation (CPR) by comparing the effects of chest compression-synchronized ventilation (CCSV) and intermittent positive-pressure ventilation (IPPV) on arterial blood gases. Methods: This prospective randomized controlled study included patients presenting with out-of-hospital cardiac arrest who were randomly assigned to the CCSV or IPPV groups. Arterial blood gas analysis was performed at the start of CPR and 10 min after initiating mechanical ventilation. Primary outcomes included changes in the arterial oxygen and carbon dioxide pressures. Results: Of the 144 patients with out-of-hospital cardiac arrest, 30 were included in the study, with 15 each assigned to the CCSV and IPPV groups. The median arterial oxygen pressure in the CCSV group was 76.1 [22.8; 260.3 interquartile range], compared with 8.8 [−1.6; 113.9 interquartile range] in the IPPV group (p = 0.250). The change in carbon dioxide pressure was −10.3 [−18.3; −2.7 interquartile range] in the CCSV group and −11.5 [−39.5; 5.6 interquartile range] in the IPPV group (p = 0.935). Wilcoxon signed-rank test results revealed significant differences in arterial oxygen and carbon dioxide pressure levels before and after treatment in the CCSV group (p = 0.026 and 0.048, respectively). However, in the IPPV group, changes in arterial partial pressure of oxygen and carbon dioxide before and after treatment were non-significant (p = 0.095 and 0.107, respectively). Conclusions: Although CCSV significantly improved oxygenation and ventilation in patients undergoing CPR, it cannot be considered superior to IPPV. Full article