The COVID-19 pandemic raised global concerns about the shortage of ventilators and revealed the challenges of rapidly scaling up production to meet emergency needs. In response, numerous teams worldwide attempted to develop emergency and simple mechanical ventilators. Among these, the CoroVent ventilator was developed to meet the urgent need for ventilatory support in the Czech Republic. The aim of this study was to describe the innovative and simple design of the CoroVent emergency ventilator, evaluate its compliance with international safety and performance standards, verify its reliability under simulated clinical conditions, and demonstrate its suitability for use in crisis scenarios. CoroVent was designed with a focus on the clinical needs of patients with COVID-19 respiratory failure and to ensure safe ventilation while maintaining a simplified design. It features volume-controlled, pressure-limited mandatory ventilation and supports key adjustable parameters such as tidal volume, respiratory rate, inspiratory-to-expiratory time ratio, inspired oxygen fraction, and positive end-expiratory pressure (PEEP). The ventilator incorporates robust safety mechanisms, including alarms and a safety relief valve, to protect against excessive airway pressures. Results confirmed the ability to maintain consistent tidal volumes, stable PEEP, and precise pressure limitation over extended periods of use. The results showed that CoroVent met the essential international standards for accuracy, including those set by the UK Medicines and Healthcare products Regulatory Agency, U.S. Food and Drug Administration, and ISO 80601-2-12. Although production of these ventilators was stopped in 2021 as the Czech Republic managed the crisis and shortage of ventilators, the results validate their reliability as emergency ventilators and indicate their potential to support critical care needs in crisis situations.

Dynamic hyperinflation is reported as a potential risk during high-frequency oscillatory ventilation (HFOV), and its existence has been documented both by physical models and by CT. The aim of this study is to determine the suitability of electrical impendence tomography (EIT) for the measurement of dynamic lung hyperinflation and hypoinflation during HFOV. Eleven healthy pigs were anaesthetized and ventilated using HFOV. The difference between the airway pressure at the airway opening and alveolar space was measured by EIT and esophageal balloons at three mean airway pressures (12, 18 and 24 cm H₂O) and two inspiratory to expiratory time ratios (1:1, 1:2). The I:E ratio was the primary parameter associated with differences between airway and alveolar pressures. All animals showed hyperinflation at a 1:1 ratio (median 1.9 cm H₂O) and hypoinflation at a 1:2 (median –4.0 cm H₂O) as measured by EIT. EIT measurements had a linear correlation to esophageal balloon measurements (r² = –0.915, p = 0.0085). EIT measurements were slightly higher than that of the esophageal balloon transducer with the mean difference of 0.57 cm H₂O. Presence of a hyperinflation or hypoinflation was also confirmed independently by chest X-ray. We found that dynamic hyperinflation developed during HFOV may be detected and characterized noninvasively by EIT.

During high-frequency oscillatory ventilation (HFOV), a situation may occur where the mean alveolar pressure (mPalv) differs significantly from the mean airway pressure (mPaw). Studies documenting the differences between these pressures during HFOV have documented states of both higher and lower mPalv compared to mPaw. The effect of HFOV parameters on the pressure difference is not yet understood. The aim of this study is to investigate how this phenomenon is affected by the ratio of inspiratory to expiratory time and the amplitude of HFOV oscillations (ΔP). The effect of the listed ventilation parameters was investigated in vitro in seven laboratory models and in vivo on nine pigs. The study found that an inspiratory to expiratory time ratio of 1:1 always results in a positive pressure difference between mPalv and mPaw, referred to as dynamic hyperinflation. At an inspiratory to expiratory ratio of 1:2 this pressure difference is negative in the majority of in vitro models of the respiratory system and in all animals. In addition, the study found that the magnitude of the pressure difference is affected by the ΔP. There is a critical value of ΔP at which the trend of the pressure gradient between the alveolar space and the airways is reversed in relation to the oscillation amplitude.

The lungs of preterm neonates can show pathologies characterized by inhomogeneity of their mechanical characteristics. That leads to major differences between time constants of each lung compartments. Currently, none of commonly used modes of mechanical lung ventilation is capable of dealing with various demands of different parts inhomogeneously damaged lungs. The aim of this study is to find out, using mathematical simulations, whether multi-frequency ventilation is better for ventilation of inhomogeneous lungs rather than mono-frequency ventilation. Minute ventilation and energy load of pulmonary parenchyma of each compartment of inhomogeneously damaged lungs was evaluated using mathematical simulations. The results prove a better distribution of ventilation using multi-frequency ventilation pattern with comparable energy load on inhomogeneous lungs compared to a protective high-frequency ventilation using frequency of 6 Hz and a lower energy load compared to a ventilation with frequency of 0.3 Hz.