ABSTRACT
In this paper, a slider type mechanical ventilator system using Ambu bag for emergency breathing assistance device was proposed and evaluated. A new type coronavirus infection occurred in early December 2019, and the infection has spread worldwide. When it became severe, respiratory failure often occurs, and there is concern about a shortage of ventilators. Meanwhile, MIT has released a blueprint for a mechanical type ventilator using an Ambu bag. In this study, we started the development based on the MIT ventilator. In our method, we proposed to reduce the load on the motor compared to the MIT type by using a horizontally moving slider to push in the pads. Using a test lung connected to Ambu bag device, we confirmed the mechanical stability between the MIT type and our proposed device. Next, we confirmed the three pads device manufacturing methods for device failure characteristics when driven for a long time (max two weeks). At last, we introduced the simple proportional type controller, and confirmed the pressure stability. The proposed a slider type mechanical Ambu bag ventilator system could realize that the Ambu bag did not move for at least one week and showed stable driving characteristics. Comparing the three types of pads manufacturing methods, the highest-performance pads used duralumin for the columns, and surface of the pad used ABS resin. Simple P controller real time pressure control experiment shows that it was necessary to device a pressure control method after carefully considering the characteristics of the check valve that responds to non-linear pressure inside the Ambu bag. © 2022 IEEE.
ABSTRACT
Background: Although mental disorders are frequent after acute COVID-19, it is unclear whether they are predicted by acute COVID-19 severity. Methods: Four months after hospital discharge for acute COVID-19 (from March 1 to May 29, 2020), 177 (63.7%) benefited from a standardized psychiatric assessment in an outpatient setting. COVID-19 objective severity was assessed during hospitalization for COVID-19. Results: The mean patient age was 57.5 years (sd=13.2) and 68 (38.4%) patients were women. During acute COVID-19, 97 (54.8%) patients were admitted to the ICU, 51 (28.8%) required invasive ventilation, 29 (16.4%) had acute delirium, and 40 (22.6%) had immunomodulatory treatments. The mean length of hospitalization was 22.0 (16.2) days, the maximum C-Reactive Protein (CRP) level was 147.9 (111.5) mg/L, and the maximum creatininemia level was 127.6 (161.1) μmol/L. Four months after acute COVID-19, 36 (20.3%) patients had at least one current mental disorder. Twenty-nine (80%) of these 36 patients were diagnosed with a new-onset mental disorder. Nine (5.1%) patients had a significant suicide risk. Mental disorders, new-onset ones and significant suicide risk 4 months after acute COVID-19 were not associated with higher acute COVID-19 severity, as assessed with length of hospitalization, ICU admission, invasive ventilation, acute delirium, immunomodulatory treatments, maximum CRP, and creatininemia levels. Conclusions: In this sample of survivors after a hospitalization for acute COVID 19, we failed to show any association between acute COVID-19 objective severity and mental disorders 4 months later. Assessment of mental disorders should be proposed to patients after hospitalization for COVID-19. Keywords: COVID-19, Mental Disorders, Depression, Anxiety, Suicide