Development of a Slider Type Mechanical Ventilator System Using Ambu Bag for Emergency Breathing Assistance

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.