Total liquid ventilation can support gas exchange in animal models of lung injury. Clinical application awaits further technical improvements and performance verification. Our aim was to develop a liquid ventilator, able to deliver accurate tidal volumes, and a computerized system for measuring lung mechanics. The computer-assisted, piston-driven respirator controlled ventilatory parameters that were displayed and modified on a real-time basis. Pressure and temperature transducers along with a lineal displacement controller provided the necessary signals to calculate lung mechanics, Ten newborn lambs (<6 days old) with respiratory failure induced by lung lavage, were monitored using the system. Electromechanical, hydraulic, and data acquisition/analysis components of the ventilator were developed and tested in animals with respiratory failure. All pulmonary signals were collected synchronized in time, displayed in real-time, and archived on digital media. The total mean error (due to transducers, analog-to-digital conversion, amplifiers, etc.) was less than 5% compared with calibrated signals. Components (tubing, pistons, etc.) in contact with exchange fluids were developed so that they could be readily switched, a feature that will be important In clinical settings. Improvements in gas exchange and lung mechanics were observed during liquid ventilation, without impairment of cardiovascular profiles. The total liquid ventilator maintained accurate control of tidal volumes and the sequencing of inspiration/expiration. The computerized system demonstrated its ability to monitor in vivo lung mechanics, providing valuable data for early decision making.

Background: The aerosolization of perfluorocarbons or surfactant has emerged as a feasible alternative to instillation, for the treatment of experimental respiratory distress syndrome. However, the biophysical properties that make these compounds useful in such therapies, significantly affect the performance of nebulizers. Therefore, in vitro studies are required to assess the suitability of new aerosolization technologies for use with these compounds. Methods: The aim of the present in vitro study was to investigate the influence of the biophysical properties of perfluorocarbons (PFD, FC75, and PFOB) and a natural porcine surfactant, Curosurf®; on aerosolization and to assess the suitability of three intratracheal inhalation catheters (IC) with different air flow rates (IC-1.23, IC-1.1, IC-1.4) coupled to a jet nebulizer, for aerosol delivery of these compounds. Results: With IC-1.23 significantly higher aerosol production rates were achieved (p < 0.0001), ranging between 6.05 ± 0.17 mL/min (FC75) and 1.94 ± 0.09 mL/min (Curosurf®), and lower percentage losses of the compound (5–21%), compared to IC-1.1 and IC-1.4 catheters. The lowest aerosolization rates were produced with IC-1.4 ranging from 0.58 ± 0.02 mL/min (FC75) to 0.14 ± 0.01 mL/min (Curosurf®), and this catheter also resulted in the highest percentage losses (25–60%). The mass median aerodynamic diameter (MMAD) ranged between 0.77 μm (PFD) and 8.29 μm (Curosurf®) with IC-1.1, whereas higher MMAD values, of between 4.84 μm (FC75) and 13.42 μm (PFOB), were observed with IC-1.23. Regardless of the catheter used during aerosolization, the perfluorocarbon with the highest kinematic viscosity showed the lowest aerosolization and emission rates and vice versa, which reveals the substantial contribution of this parameter that should accordingly be considered in the design of perfluorocarbon aerosol drug delivery systems. Conclusions: Jet aerosolization of perfluorocarbons or surfactant with the intratracheal inhalation catheters seems to be a suitable method for treating experimental respiratory distress syndrome, because it delivers relatively high doses of perfluorocarbons and surfactant to the lungs in a respirable size doplets.

The prediction of loss of position in the offshore industry would allow optimization of dynamic positioning drilling operations, reducing the number and severity of potential accidents. In this paper, the probability of an excursion is determined by developing binary logistic regression models based on a database of 42 incidents which took place between 2011 and 2015. For each case, variables describing the configuration of the dynamic positioning system, weather conditions, and water depth are considered. We demonstrate that loss of position is significantly more likely to occur when there is a higher usage of generators, and the drilling takes place in shallower waters along with adverse weather conditions; this model has very good results when applied to the sample. The same method is then applied for obtaining a binary regression model for incidents not attributable to human error, showing that it is a function of the percentage of generators in use, wind force, and wave height. Applying these results to the risk management of drilling operations may help focus our attention on the factors that most strongly affect loss of position, thereby improving safety during these operations.

Our aim was to develop a computerized system for real-time monitoring of lung mechanics measurements during both gas and liquid ventilation. System accuracy was demonstrated by calculating regression and percent error of the following parameters compared to standard device: airway pressure difference (DeltaP_aw), respiratory frequency (f_R ), tidal volume (V_T), minute ventilation (V'_E), inspiratory and expiratory maximum flows (V'_ins,max, V'_exp,max), dynamic lung compliance (C_L,dyn), resistance of the respiratory system calculated by method of Mead-Whittenberger (R_rs,MW) and by equivalence to electrical circuits (R_rs,ele), work of breathing (W_OB), and overdistension. Outcome measures were evaluated as function of gas exchange, cardiovascular parameters, and lung mechanics including mean airway pressure (mP_aw). DeltaP_aw, V_T, V'_ins,max, V'_exp,max, and V'_E measurements had correlation coefficients r = 1.00, and %error < 0.5%. f_R, C_L,dyn, R_rs,MW, R_rs,ele, and W_OB showed r ges 0.98 and %error < 5%. Overdistension had r = 0.87 and %error < 15%. Also, resistance was accurately calculated by a new algorithm. The system was tested in rats in which lung lavage was used to induce acute respiratory failure. After lavage, both gas- and liquid-ventilated groups had increased mP_aw and W_OB, with decreased V_T, V'_E, C_L,dyn, R_rs,MW, and R_rs,ele compared to controls. After 1-h ventilation, both injured group had decreased V_T, V'_E, and C_L,dyn, with increased mP_aw, R_rs,MW, R_rs,ele, and W_OB. In lung-injured animals, liquid ventilation restored gas exchange, and cardiovascular and lung functions. Our lung mechanics system was able to closely monitor pulmonary function, including during transitions between gas and liquid phases.

Defrost cycles in shipboard refrigeration plants are typically initiated on fixed schedules or by operator judgement, which can lead to unnecessary energy use and temperature variability during the transport of frozen products. This study proposes a data-driven predictive maintenance approach to trigger defrost on demand in a merchant reefer vessel carrying frozen tuna. A total of 76,692 operational records from cargo-hold air coolers and holds were analysed, including delivery and return air temperatures, hold air temperature and relative humidity. The records were modelled to show their behaviour under real voyage conditions. The modelled strategy indicates that 66.55% of defrost cycles performed during the study period were unnecessary, suggesting substantial scope to reduce defrost frequency and associated disturbances. These findings demonstrate the feasibility of implementing machine learning (ML)-based decision support for maritime refrigeration. This enables defrost-on-demand scheduling, which has the potential to enhance operational efficiency while supporting product quality, sustainability and traceability in the frozen tuna supply chain.