Reading CPAP data from the SD card: OSCAR step by step

Important: OSCAR is a program for viewing your data – not a medical device and not a diagnostic tool. Please discuss values and anything unusual with your doctor or sleep lab. Therapy settings are made only by your doctor.

What is OSCAR?

OSCAR (Open Source CPAP Analysis Reporter) is free, open-source software for Windows, macOS and Linux. It reads the data that many CPAP and BiPAP devices store on their SD card and displays it as daily overviews and charts: usage time, pressure, mask leak and the events detected by the device.

Whether your device is supported is listed on the official OSCAR website. This is the case for many ResMed devices (e.g. S9, AirSense 10, AirCurve 10) and Philips Respironics devices.

Download OSCAR in our download centre →(Windows 10/11 and macOS; project page: sleepfiles.com/OSCAR)

What you need

• Your CPAP device with the SD card inserted (on many devices at the side or back).
• A computer with an SD card reader (built in or as a USB adapter).
• OSCAR – free in our download centre.

Step by step

• 1. Switch the device off. End therapy and wait until the device is in standby. Do not remove the card while the device is running.
• 2. Remove the SD card. Press the card gently and it pops out. Handle it with care – do not bend it or let it get wet.
• 3. Insert the card into your computer. Do not open or change any files on the card and do not format it. If the computer offers to check, scan or format the card, decline.
• 4. Start OSCAR and create a profile. When you first start the program, you create a profile. The details stay on your computer.
• 5. Import the data. Click “Import” or “Import CPAP data” and select the SD card. OSCAR copies the data to your computer.
• 6. Eject the card safely and put it back. Eject the card via the operating system and reinsert it into the device before your next therapy session.

The main views – simply explained

• Daily view: shows one night in detail – when the device was running, pressure, leak and the events marked by the device on the timeline.
• AHI: the device's calculated value for breathing pauses and shallow breathing per hour. It is an estimate by the device, not a medical measurement. How your value should be interpreted is assessed by your doctor.
• Leak: shows how much air escapes unintentionally, usually at the mask. High leak values often point to mask fit or a worn cushion – see mask leaks.
• Pressure: on automatic devices (e.g. AutoSet) you can see how the pressure adapts during the night. What the values mean: CPAP pressure.
• Overview: shows trends over weeks and months, such as usage per night – a good basis for talking to your doctor.

Discussing the data with your doctor

OSCAR can create or print reports as PDF. Feel free to take them to your appointment. Never change settings on your own based on the charts.

Frequently asked questions

We do not replace medical advice. Only change therapy pressure and settings as prescribed by your doctor.