Most ResMed CPAP and APAP machines keep a detailed record of every night's therapy on a small SD card. That card holds EDF (European Data Format) files — binary logs of your breathing patterns, pressure levels, and respiratory events. Until recently, reading those files meant installing desktop software. With AirwayLab, you can open them directly in your browser, with nothing to install.
What's on your ResMed SD card?
Your ResMed machine stores two types of data on its SD card:
- Summary data— nightly AHI, mask leak, and usage hours, similar to what the device screen shows
- Detailed EDF files— continuous waveforms of your breathing patterns, flow rate, pressure, and respiratory events recorded at higher resolution throughout the night
The EDF files are where the detail lives. They contain the flow signal that makes it possible to look at things like flow limitation and RERA patterns — aspects of your breathing that a headline AHI score doesn't capture.
Finding your files
DATALOG/ containing .edf files organised into one dated folder per night.Most ResMed AirSense 10 and AirSense 11 machines use this same folder structure. If you're not sure whether your device records detailed data, check that the SD card slot is present and the card has been in the machine during recent sessions.
Opening your data in AirwayLab
.edf files — into the drop zone. You can also click to browse.What you'll see
Once your data is loaded, AirwayLab displays:
Session list
Each night as a separate entry with date, total duration, and AHI.
AHI summary
Broken down by obstructive, central, and hypopnea counts per hour.
Flow limitation index
Describes the frequency of partial upper airway narrowing across the night.
RERA timeline
Respiratory effort-related arousals displayed as a visual pattern alongside the flow waveform.
Breathing waveform
The full flow signal from your EDF file, scrollable night-by-night.
AirwayLab shows you what's in your data. It doesn't tell you what your numbers mean clinically, and it doesn't make recommendations about your therapy. For clinical interpretation of what you see, discuss it with your clinician or sleep specialist.
What it covers that a desktop install can't
Tools like OSCAR have long been the go-to for browsing CPAP waveforms on the desktop. AirwayLab reads the same cards in the browser and scores each night for you, which also covers the cases a desktop install does not: a quick look without setting anything up, a machine where you can't install software, or sharing a link to your session data.
Read more in AirwayLab vs OSCAR: How They Compare.
Read your ResMed data now
Drag in your SD card files and see your AHI, flow limitation, and RERA data in seconds. No download. No account. 100% private.
AirwayLab is informational only. Nothing displayed constitutes a clinical diagnosis or therapeutic recommendation. Always discuss your therapy data with your clinician for clinical interpretation.
Related reading
How to Read Your CPAP Data — a full guide to CPAP metrics beyond AHI.
AirwayLab vs OSCAR — how AirwayLab and OSCAR compare on the same SD card data.
Analyse CPAP Data in Your Browser — no download, no cloud, no account.
detailed setup guide — step-by-step AirSense 10 SD card guide.
data access guide — step-by-step AirSense 11 SD card guide.
troubleshooting guide — AirCurve BiPAP SD card guide.
Glossary
Flow limitation — what it means and how AirwayLab measures it.
RERA (Respiratory Effort-Related Arousal) — how RERAs differ from apneas and why they matter.
Glasgow Index — the 9-component breath shape scoring system.