If you use a CPAP or BiPAP machine and want to understand your therapy data, you've probably heard of OSCAR (Open Source CPAP Analysis Reporter). It's been the go-to tool for PAP data analysis for years, and for good reason. But OSCAR and AirwayLab solve different problems. This article explains what each tool does well, where they differ, and why many users benefit from using both.
What OSCAR Does Well
OSCAR deserves its reputation. It's a mature, reliable desktop application with features no other free tool matches:
- Interactive waveform browsing with zoom, pan, and event marking at breath-by-breath resolution
- Multi-device supportincluding ResMed, Philips, F&P, and others
- Historical data stored locally with long-term trend views across months and years
- Detailed event logs showing individual apnea, hypopnea, and leak events on a timeline
- Active community on ApneaBoard.com and other forums, with years of shared knowledge
For manual waveform inspection and event-by-event review, OSCAR is hard to beat. If you need to zoom into a specific 30-second window and examine individual breaths, OSCAR is the right tool.
What AirwayLab Adds to the Picture
While OSCAR excels at interactive waveform inspection, AirwayLab focuses on a different layer: automated breath-by-breath analysis and composite metrics. These are complementary approaches to understanding the same data.
Flow Limitation Scoring
AirwayLab runs four algorithms on the flow waveform to quantify flow limitation automatically. This complements OSCAR's visual waveform inspection with numerical metrics.
RERA Estimation
AirwayLab's NED engine identifies sequences of flow-limited breaths that may represent respiratory effort-related arousals, and estimates a RERA index from the flow signal alone.
Composite Metrics
The Glasgow Index (9-component breath shape score), FL Score, Regularity, Periodicity, and more synthesise thousands of breaths into numbers you can track over time.
Browser-Based
AirwayLab runs in your browser with no installation. Upload your SD card and get results on any device. OSCAR is a desktop application with more control over local data management.
Side-by-Side Comparison
| Feature | OSCAR | AirwayLab |
|---|---|---|
| Interactive waveform zoom | Yes | Viewer only |
| Multi-device support | Yes (5+) | ResMed |
| Event-by-event timeline | Yes | Summary view |
| Historical data management | Yes | Per-session |
| Flow limitation scoring | Visual inspection | 4 engines |
| RERA estimation | Different focus | NED engine |
| Composite metrics | Raw data view | Glasgow, FL, NED |
| Oximetry analysis | Yes | 17 metrics |
| Platform | Desktop app | Browser |
| Privacy | Local files | Browser-only |
| Open source | Yes | Yes (GPL-3.0) |
| Cost | Free | Free core |
Privacy: Both Tools Get It Right
Both OSCAR and AirwayLab keep your data under your control. OSCAR stores everything locally on your computer. AirwayLab processes everything in your browser using Web Workers, and no data leaves your device unless you explicitly opt in to features like AI insights or community data contribution.
This stands in contrast to manufacturer apps (myAir, DreamMapper) that upload your data to corporate servers and may share it with insurance providers. Both open-source tools give you the analysis without the privacy trade-off. Read more about PAP data privacy and your rights.
Using Both Tools Together
OSCAR and AirwayLab aren't competitors; they're complementary. A practical workflow:
1. Start with AirwayLab for the big picture
Upload your SD card, get your Glasgow Index, FL Score, RERA estimate, and IFL Risk Score. These composite metrics tell you whether flow limitation is a problem and how severe it is. The traffic light system makes interpretation straightforward.
2. Use OSCAR to investigate specifics
If AirwayLab flags elevated flow limitation in the second half of the night (H2), open that session in OSCAR and zoom into the waveforms. Look for the specific events and patterns. OSCAR's interactive zoom is unmatched for this kind of detailed inspection.
3. Track trends in AirwayLab, verify in OSCAR
After a pressure or EPR change, monitor your AirwayLab metrics across nights. If a metric shifts significantly, confirm the change by inspecting representative waveforms in OSCAR. This gives you both statistical confidence and visual verification.
Which Tool Is Right for You?
OSCAR is best if you...
- Need to browse individual waveforms interactively
- Use a non-ResMed device (Philips, F&P)
- Want years of historical data in one view
- Prefer a desktop application
- Already know how to read flow waveforms
AirwayLab is best if you...
- Want automated flow limitation analysis
- Want a quick summary of your breathing patterns and metrics
- Want metrics that go beyond AHI (Glasgow, NED, RERA)
- Prefer browser-based tools with no installation
- Want AI-powered insights about your patterns
- Need exportable reports for your clinician
Learn More
Beyond AHI: Why Your Sleep Apnea Score Might Be Misleading You — the research case for metrics beyond AHI.
Understanding Flow Limitation — what flow limitation is and how it affects your sleep.
AirwayLab Methodology — detailed documentation of all four analysis engines.
OSCAR Official Site — download and documentation for OSCAR.
A note on self-analysis
Both OSCAR and AirwayLab are informational tools, not diagnostic devices. Flow limitation analysis from SD card data is an estimate, not a polysomnography-grade measurement. Always discuss your data with your sleep physician. The metrics provided are for educational purposes and to inform clinical conversations.
Try AirwayLab Free
Upload your ResMed SD card and get flow limitation analysis in minutes. Four research-grade engines, composite metrics, RERA detection, and trend tracking. No installation, no account required, 100% private.