Hello thinktwo, thank you for the quick reply.
I received the following response to my inquiry with SAS Air:

"Thanks for contacting SAS Medical.
You are welcome to bring and use your CPAP device Prisma 20A from Lövenstein on SAS as long as its battery is driven.
Please advise if battery driven and please send us your booking reference as well as we must register approval in your reservation."

I received the following response to my question about whether a power bank is permitted as a battery:

"Unfortunately, it's not permitted to use your power bank on SAS. We can only approve the use of your CPAP if battery driven.
We hope that you find a solution with a battery."

Since I'm flying business class, I'll still try to use my CPAP device.