## 4 Discussion  
The results of our testing showed that the CoroVent ventilator provides stable, safe, and accurate ventilatory support. A key advantage of CoroVent is its simple design, which facilitates rapid production while maintaining essential features for patient safety. Given the specific COVID-19 progression associated with induced ARDS and urgent development timeline, a single ventilation mode suitable for this etiology was selected. By focusing on volume-controlled, pressure-limited mandatory ventilation, the design minimizes complexity without compromising clinical efficacy. The ventilator incorporates multiple layers of safety, including software-controlled pressure limits, hardware-adjustable maximum pressure settings, and a mechanical safety relief valve, all of which act as protective barriers to minimize ventilator-induced lung injury. The performance stability test showed no significant deviation in Paw and _Flow_ waveforms and _VTi_ over a 24 h period, even under unfavorable conditions. This indicates that the ventilator maintains consistent function over extended use. The ability to operate for over two hours on battery power, well above the ISO-required minimum of 30 min [22], demonstrates robust performance under power failure conditions, which is critical for clinical readiness in emergency and mobile settings. This aligns with the importance of incorporating reliable control strategies to address potential operational failures in emergency biomedical systems [32]. High accuracy of _VTi_ delivery when compared to an independent reference suggests that the ventilator can support effective gas exchange while minimizing the risks associated with hypoventilation or hyperventilation. Additionally, _PEEP_ stability was maintained across different _VTi_ settings, further validating the reliability of the system in providing consistent _PEEP_ to prevent alveolar collapse and improve oxygenation. The CoroQuant pneumotachograph flow sensor, specifically designed for CoroVent, with its processing algorithm and electronics, demonstrated accurate monitoring of _VTi_ within acceptable limits when compared to the reference measurements. Accurate monitoring is essential for safe and effective mechanical ventilation, allowing clinicians to adjust settings based on real-time patient needs. Some of the inspiratory branch characteristics, such as the dependence of measured _FiO_2 on set _FiO_2, the relationship between measured _VTi_ and set _FiO_2, and the interaction between delivered _VTi_ and maximum pressure relative to respiratory system compliance and resistance were tested previously during the design of the inspiratory flow generation [28]. Figure 11: (**A**) _P_aw and its pressure limitation during the whole respiratory cycle for eleven different _PEEP_ settings. (**B**) The dependance of measured _MV_ on different _PEEP_ settings during pressure limitation. (**C**) The dependance of measured inspiratory tidal volume on different _PEEP_ settings during pressure limitation. The shortage of commonly available flow sensors during the COVID-19 pandemic led to the decision to design a custom flow sensor, CoroQuant. The initial design and optimization of the CoroQuant was carried out using computational fluid dynamics (CFD) simulation in COMSOL Multiphysics (version 5.4.0.225, COMSOL, Inc., Burlington, MA, USA). The first sensor prototypes were manufactured and tested using 3D printing technology. During the optimization, several positions and shapes of the resistance element within the sensor body were tested to improve the performance of the sensor. This process included testing using common CFD simulation methods [33; 34; 35]. The final sensor design was chosen based on extensive experimentation with various resistance element shapes and configurations. A metal mold was then created for plastic injection molding, ensuring reproducible and consistent sensor properties. The design and measurement results were described in the study by [PERSON] et al. [26].