Hi all, today is a big milestone for our ventilator development. We successfully demonstrated mixing Air & O2 to a target ratio (FiO2)! This is a critically important feature for the ventilator to have. The ventilator mixes room air with O2 from a compressor. Attached is a data trace showing some data we recorded during our mixing test. In the center plot, you can see the flow of O2 in blue, the flow of air in yellow, and the total gas flow in green. In the bottom plot you can see the integrated volumes of air, O2, and total gas volume. In this test we are mixing to an FiO2 of 86%, but we've successfully mixed to several other ratios as well.

Here is a real-time video of our ventilator diagnostic program, showing how we can mix air and oxygen to a target ratio (also called "FiO2.") There's a lot going on this screen, so pay attention mostly to the second and third plot from the top, and the user entry box called "FiO2" on the left hand panel. You can see when the user changes the "FiO2" setting in the left hand panel, the flow levels for air (yellow) and O2 (blue) change in the second plot. The third plot shows the integrated volumes for air, O2, and total volume. You can see that the mix ratio tracks the user's input. There's still some fine-tuning required, but this is an important proof of concept demo!