Medical disclaimer
AirwayLab is a data-visualization tool, not a medical device. The metrics and charts it displays are for informational purposes only and do not constitute medical advice, diagnosis, or treatment. Always discuss your therapy data and any questions about your therapy with your prescribing clinician or sleep physician.
Your CPAP machine runs quietly every night, logging detailed records of every session: hours of use, AHI, flow limitation events, mask leak, and pressure. Most of that detail never appears on the device display or inside a manufacturer app — it lives on a small SD card tucked into the side of the machine.
Once you know how to download your CPAP data from an SD card, you have access to a complete night-by-night record of your breathing patterns. This guide walks you through the whole process: removing the card, reading it on your computer, and getting those records into AirwayLab.
Which CPAP Machines Use SD Cards?
Most modern PAP devices record detailed session data to a removable SD card. The most common machines you are likely to encounter:
| Machine | Card format | Slot location |
|---|---|---|
| ResMed AirSense 10 | Standard SD | Side door, left panel |
| ResMed AirSense 11 | Standard SD | Side door, left panel |
| Philips DreamStation (Gen 1) | Standard SD | Rear, behind a door |
| Philips DreamStation 2 | microSD | Internal slot (see note) |
| Fisher & Paykel SleepStyle | microSD | Side panel |
DreamStation 2 note
Philips moved to an internal microSD slot in the DreamStation 2. Some units allow user access; others are not designed for routine card removal. Check your machine's user manual before attempting.
Older machines
ResMed S9 devices also used a standard SD card in the same left-panel slot as the AirSense 10. If your machine is not listed, check the user manual or the manufacturer's support pages.
Step 1: Remove the SD Card Safely
Always power off and unplug your machine before removing the card. The machine can still be writing session data for a short time after a session ends, and pulling an active card can corrupt the filesystem.
ResMed AirSense 10 and 11
Turn the machine off and unplug it.
Open the small door on the left side of the device — it snaps open with a fingernail.
Press the SD card inward gently; it will spring-eject.
Slide the card out.
Philips DreamStation (Gen 1)
Power off the machine.
Open the rear door (it pivots upward).
Press and release the SD card to eject.
Remove the card.
Fisher & Paykel SleepStyle
Power off the machine.
Locate the microSD slot on the side panel.
Press gently to eject, then remove.
microSD adapter
If you have a microSD card, you will need a microSD-to-SD adapter (often included in the card's packaging) or a USB microSD reader to connect it to your computer.
Step 2: Read the Card on Your Computer
Windows
Insert the SD card into your PC's built-in card reader, or use a USB SD card adapter.
Open File Explorer — the card appears as a removable drive.
Open the drive. You will see a folder named DATALOG (ResMed) or a similar data folder (Philips, Fisher & Paykel).
Do not rename, move, or delete any files.
Mac
Insert the SD card into your Mac's built-in card reader, or use a USB-C SD card adapter.
The card appears on the Desktop and in the Finder sidebar as a removable volume.
Click to open it — the data folders are visible inside.
Leave the folder structure exactly as it is.
Card not visible?
- Mac:Go to Finder → Settings → General and make sure “External disks” is checked.
- Windows: In File Explorer, go to View → Show → Hidden items.
Step 3: What Is on the Card?
The SD card holds your therapy records — nightly session files in a proprietary binary format. You will not be able to open them in a text editor, but the file dates correspond to session dates, so you can confirm the card contains the nights you are looking for.
ResMed cards typically contain
DATALOG/— individual session files, one per nightSTR.edf— a summary EDF file covering multiple sessions
Philips DreamStation cards
Use a different folder structure but follow the same principle: one or more binary session files per night.
The data includes metrics like AHI, mask leak, pressure records, and — on ResMed machines with detailed recording enabled — high-resolution flow waveforms. Exact metrics vary by machine model and firmware version.
No files on the card?
Detailed data recording may be disabled in your machine's clinical settings. A sleep technician or your prescribing clinic can check and enable it.
Step 4: Upload Your Data to AirwayLab
Go to AirwayLab /analyze.
Click “Upload SD card data” and select either the full SD card or just its data folder.
AirwayLab processes the files entirely in your browser — your data never leaves your device.
Your sessions appear as a timeline. Select any night to see AHI, flow limitation events, leak rate, pressure records, RERAs, and more.
Format support
AirwayLab supports ResMed EDF and CPAP data formats and Philips DreamStation data natively. If you already use OSCAR, you can also import from an OSCAR data directory.
Free and open source
AirwayLab is free and always will be. The source code is GPL-3.0 licensed and publicly verifiable. Premium features support ongoing development, but the full analysis is available without creating an account.
Frequently Asked Questions
Can I damage my CPAP machine by removing the SD card?
Not if you power it off first. The card records during a session and data is written at session end. Powering down before removal is the one step not to skip.
How often should I download my data?
SD cards on most machines hold at least a year of sessions. Many users download every month or two, or when they want to look at a specific period. There is no technical reason to download more frequently.
My ResMed AirSense 11 does not seem to have an SD card — am I missing something?
The AirSense 11 has both an SD card slot (same location as the 10) and myAir cloud connectivity. The SD card is present and records the same detailed data as the AirSense 10; it is just less prominently documented in the consumer-facing materials.
Can I upload my CPAP data without removing the SD card?
On some machines with cloud sync enabled, data uploads automatically to the manufacturer's platform. AirwayLab currently reads from SD card upload or OSCAR import; direct cloud sync is on the roadmap.
What is AHI?
AHI stands for Apnea-Hypopnea Index — the number of apnea and hypopnea events recorded per hour of sleep. Your machine logs this metric each session. Your sleep physician can help you interpret what your recorded AHI values mean in the context of your therapy.
Medical disclaimer
AirwayLab is a data-visualization and analytics tool, not a medical device. Nothing on this page or in the AirwayLab application constitutes medical advice, a clinical diagnosis, or a treatment recommendation. Your SD card data is a record of what your machine logged — it describes usage and recorded metrics, not a clinical assessment of your health. Always discuss your data and any therapy questions with your prescribing clinician or sleep physician.
Ready to See Your Data?
Upload your SD card to AirwayLab and see your therapy sessions as a night-by-night timeline. Free, browser-based, and your data never leaves your device.