Paper Title
Air Flow Sensor Instability Measurement for A Slider Type Mechanical Ventilator System Using Ambulance Bag for Emergency Breathing Assistance

Abstract
In this paper, we are examined a air flow sensor instability for our developed a slider type mechanical ventilator system for using ambulance bag. A new type coronavirus infection occurred in early December 2019, and the infection has spread worldwide. When it become severe, and a shortage of ventilators were occurred in many countries. Against this problem, MIT has released a blueprint for a low-cost mechanical type ventilator system using an ambu-bag. However, since the MIT mechanism realize the ventilation by rotationally moving two pads and pushing the ambu-bag mechanically, it would occurred the air pressure instability / air flow instability. At least, the two factors - air pressure / air flow parameters are necessary to measure accurately at all times while the temperature and humidity change at the millisecond level. In this paper, we concentrated the instability of ”air flow sensor” - as a ventilator, it is necessary to push in an accurate air flow (such as 500 ml) into the lungs. First, using a two air flow sensors connected as serial and to 500 ml syringe, we confirmed the air flow instability of air flow sensor. The measurement result said that about 20 % difference of the volume flow comparing with the syringe. Next, the same experiment was conducted with a different connection method for the flow meter. The results showed that the inlet of the flowmeter should not be connected directly to the air outlet. Keywords - Ventilator, Mechanical type, Ambulance bag, MIT type ventilator, Air flow sensor