Hello Trki. I am sorry about your husband's combined issues. I have one idea that may be of assistance. There are wearable oximeter rings which can track the oxygen during daytime activities and during sleep. They work on bluetooth so you can move around freely. Some, such as "Wellue", have vibration alarms to alert you to low oxygen. You set the parameter point. This might help track your husband's patterns at night. I hope his procedure goes well. Prayers!