To put our oxygen system to the test, we did what everyone says never to do - tied a plastic garbage bag around Jim's (our founder) neck to see just how long he could last without oxygen. Nobody else wanted to volunteer, surprisingly.
The plastic garbage bag was a kitchen size with the GLAD handles, which made for a perfect testing unit. With the bag on and the handles cinched, there was very little trapped oxygen inside the bag and available for breathing.
Our wearable forehead placed oximeter with wireless com to our Aithre Connect iOS app was used to monitor the blood oxygen levels in real-time with trend graphing.
First with no oxygen system used, our Jim was able to last for only 2.5 minutes before his SPO2 dropped aggressively into the 80% range. His breathing was intense and he reported being very light headed and fatigued at this point. Heart rate was rising quickly, so we discontinued the test at that point. Conclusion: very little time is available for breathing in a small enclosed area because the limited oxygen is quickly converted to carbon dioxide.
We then hooked up the oxygen system with the nasal cannula and opened the valve to 0.5LPM of 99.99% oxygen flow. Using the same kitchen sized plastic garbage bag, the handles were cinched around Jim's neck with the same limited space for trapped atmospheric oxygen. Jim was able to last for a full 15 minutes with no drop in SPO2 blood oxygen. In fact, the blood oxygen actually rose toward the end to around 96%.
Jim did experience hyperventilation and rapid breathing, in association with a rapid spike in heart rate. Medical professional input indicated this was likely due to the change in pH from lower carbon dioxide and higher oxygen availability as compared to the typical low 20% atmospheric oxygen. Panic and anxiety may have also contributed to the increase in breathing rate and high heart rate after being trapped in a plastic bag for 15 minutes. Conclusion: blood oxygen can increase when trapped in a small enclosure when using the oxygen system, but can be associated with hyperventilation. Additional testing and training is required to extend the time beyond 15 minutes without hyperventilation.
Our medical advisor and flight advisor both indicated that the hyperventilation was not fatal and the body would have recovered over time given the high oxygen levels.