## 3 Results
### Clinical Data of the Participants  
Figure 4 shows the results related to the vital signs of the 51 study patients, regardless of the type of outcome observed (the need for mechanical ventilation or not). Regarding heart rate (Figure 4a,b), temperature (Figure 4c,d), and respiratory rate (Figure 4e,f), we observed that there was no statistical difference between the mean values found for these parameters in D0 when compared to D1, D4, and D7 (\(p>0.05\)). The mean respiratory rate on D0 during the monitoring days (D1, D4, and D7) of the patients who did not need intubation was the same, around 21 bpm, except for D1, which was 22 bpm (Table S4). However, intubated patients showed a different behavior, the average observed for this parameter on D0 was 28 bpm, a value higher than the monitoring days (25, 21, and 21 irpm for D1, D4, and D7, respectively) (Table S4). Considering SpO\({}_{2}\), there was an increase in the mean values of this variable comparing D0 with all monitoring days (D1, D3, and D7) with a significant difference (\(p<0.05\)) (Figure 4h). The mean SpO\({}_{2}\) among patients who did not require intubation was 92% on D0 and went to 95% regardless of the monitoring day. Whereas for participants who needed intubation, the mean for this parameter was 90% (D0) to 91, 93, and 97%, considering D1, D4, and D7, respectively (Table S4). Of the 51 study patients, 35 individuals were admitted to the ICUs of the Espanhol Hospital. Thus, Figure 5 presents the results of the blood gases of these patients during the monitoring days (D1, D4, and D7). The values found for the parameters evaluated in this exam, in this case, paCO\({}_{2}\) (Figure 5a,b), paO\({}_{2}\) (Figure 5c,d), SaO\({}_{2}\) (Figure 5e,f), pH (Figure 5g,h), HCO\({}_{3}\) (Figure 5i,j), and Lactate (Figure 5k,l), showed no significant difference (\(p<0.05\)) compared to the monitoring days (D1, D4, and D7). The mean values for paCO\({}_{2}\) of participants who did not need mechanical ventilation after using the device for 4 or 7 days were lower than the mean values found for patients who required intubation, regardless of the day of monitoring (D1, D4, or D7) (Table S4). More specifically, the paCO\({}_{2}\) of patients who did not require intubation had mean values of 37.15, 39.71, and 36.00 mmHg on D1, D4, and D7, respectively, whereas participants who were intubated had mean values of 48.31 (D1), 48.67 (D4), and 42.00 (D7) mmHg (Table S4). Concerning paO\({}_{2}\), the mean values found for patients who did not need intubation were 115.38, 107.33, and 103.00 mmHg for D1, D4, and D7, respectively, whereas for patients who required intubation, the values obtained were 89.92, 106.91, and 123.00 for D1, D4, and D7, respectively, indicating an inverse trend to that found for paCO\({}_{2}\) (Table S4). Regarding SaO\({}_{2}\), unlike SpO\({}_{2}\), there was no significant difference (\(p>0.05\)) when comparing the 3 (three) days of monitoring (D1, D4, and D7) (Figure 5). It is noteworthy that the SaO\({}_{2}\) level of both the patients who did not need intubation and those who needed the intervention was higher on D4 or D7 when compared to the level found on the first day of monitoring (D1); these values were higher than \(>\)90% (Table S4). Furthermore, we noted that the values found for SaO\({}_{2}\) were higher than those found for SpO\({}_{2}\), regardless of the monitoring day (Table S4). The values referring to blood pH and the concentration of lactate and HCO\({}_{3}\)' remained stable during the use of the device. In both the patients who needed intubation and those who did not, except for the level of HCO\({}_{3}\)' among intubated patients, we observed a greater than 100% increase in blood buffer concentration, comparing day 4 (D4) (1.70 mmol\(\cdot\)L\({}^{-1}\)) with day 7 (D7) (4.45 mmol\(\cdot\)L\({}^{-1}\)) of monitoring (Table S4). Figures 6-8 show the analysis of the results of the imaging examination of the study patients before using the device, according to the observed primary outcome.