CO2 regulation to stabilize periodic breathing

I observed that with one mask/pressure setting my heart rate and volume of breath was increasing throughout the night until I awoke gasping for air.

I surmised that I was re-breathing too much and the CO2 level was increasing. I punched holes in my mask. The CPAP tries to hold the same pressure, so I get more escaping and less re-breathing.

My requirements change with health, activity and other factors. I would think that regulating the CO2 level would more directly regulate the sensations which trigger breathing.

CPAP regulating air volume treats the need for air, but ignores the trigger mechanisms for breathing. It is a PID feedback loop with too much delay and no direct coupling.

I believe a pressure-proportional bleed valve could be tuned to regulate re-breathing and stabilize periodic breathing. It would not be a direct control from CO2 level, but I suspect exhale volume and pressure may be closely related.

My experience tells me that different masks have different size exhale holes. Using a mask where they are too small for me personally has me feeling like I am drowning and can't breathe. I am not sure about your suppositions based on exhale/exhaust hole function but you may be right. I believe this issue may be one of more significant reasons for masks working for one person and not another.

I'm now at: AHI 0.72 Obst Index 0.00 Hypopnea 0.56 Clear Airway 0.16 Flow limit 0.00 RERA 0.08

Ave SpO2 93.27 Min SpO2 88.00 % in SpO2 drop 5.37%

And my new sleep DR didn't even read data from my machine but wants to sell me a new machine... I dumped her.