GUIDE · 6 MIN READ

How to read your CPAP SD card

Everything your ResMed machine knows about last night is on a small SD card in its side. To read your CPAP SD card you need three things: a minute to take the card out safely, a card reader that fits your computer, and somewhere to upload it. This guide walks through all three for the AirSense 10, AirSense 11 and AirCurve 10 and 11, on Mac and Windows, ending with an upload to Apnealytics. The whole process takes about five minutes the first time and under two after that.

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Before you start

Turn the machine off and let it finish. After you stop therapy, the machine writes the final summary to the card. Wait until the screen is idle, around 30 seconds, before removing the card. Removing it mid-write can corrupt the last night.
Never format the card. Your computer may offer to. Decline. Formatting erases the data and the folder structure the machine expects.
Do not rename or move anything on the card. Read it, upload it, put it back.

Step 1: Remove the card from your machine

AirSense 10 and AirCurve 10

With the machine off, look at the left side (as you face the screen). There is a small rubber flap over the SD card slot.
Lift the flap.
Press the card in gently until it clicks, then release. It will pop out a few millimetres.
Pull the card out and set it label-up on a clean surface.

AirSense 11 and AirCurve 11

With the machine off, find the SD card slot on the left side behind a small cover.
Open the cover.
Press the card in until it clicks and let it spring out.
Pull it clear.

S9 and Lumis

The S9 has an SD slot on the back-left behind a cover; the Lumis follows the same layout as the AirCurve 10.

A note on the AirMini

The ResMed AirMini has no SD card. There is nothing to remove and nothing any third-party tool can read. Its only data path is the myAir app over Bluetooth.

Step 2: Choose a card reader

The card is a full-size SD card (not microSD). Most laptops no longer have a built-in slot, so you will likely need a reader. Any basic reader works; speed does not matter.

USB-C only (recent MacBooks, many Windows ultrabooks): buy a USB-C SD card reader that lists "SD / SDHC / SDXC" support. Compact ones with no cable travel well.

USB-A (the rectangular port): buy a USB-A SD card reader. Inexpensive and widely available.

Both ports: either, or a dual-connector reader.

Built-in SD slot: you need nothing. Many older MacBook Pros, iMacs and Windows laptops have one.

Avoid readers that only accept microSD.

Step 3: Open the card on your computer

On a Mac

Insert the card into the reader and the reader into the Mac.
A drive appears on the desktop or Finder sidebar, possibly named "Untitled" or "NO NAME".
If macOS says the disk was not readable, do not click Initialize. Click Ignore, re-seat the card, and try again; try a different reader before assuming the card is faulty.
Open the drive.

On Windows

Insert the card and reader.
Open File Explorer. The card appears as a removable drive, usually D: or E:.
If Windows asks "Do you want to scan and fix?", choose "Continue without scanning".
If Windows asks to format the drive, click Cancel. Re-seat the card and try again.
Open the drive.

Step 4: What is on the card

A ResMed card contains a small set of files and one large folder. You do not need to understand them to upload, but it helps to recognise a healthy card.

Identification.json (or.tgt): the machine's serial number and model, which tells Apnealytics which machine the card came from.
STR.edf: the summary file, one row per night with AHI, usage, leak, pressure and settings. This drives the dashboard.
DATALOG/: one folder per date holding the high-resolution EDF files: airflow, pressure, leak, events and, on some machines, oximetry (SAD.edf). This is where waveforms come from, and why the card runs to gigabytes.
SETTINGS/: settings snapshots.

If DATALOG is empty, the machine may not be set to record detailed data; that is a clinician-side setting on some machines. Ask your DME.

Step 5: Upload to Apnealytics

Sign in at my.apnealytics.com in your browser. Card import is web-only today; the phone apps do not read the card.
Go to Import.
Drag the entire card drive onto the upload area, or click to choose it and select the card's root folder. The upload is folder-aware, so it finds STR.edf and DATALOG itself. Do not select individual files.
Wait. Cards run from 2 to 6 GB, and the upload goes directly from your browser to your private storage (Cloudflare R2), never through a middle server. It is resumable: if your connection drops, start it again and it picks up where it left off.
When processing finishes, your Nights list and dashboard update. Re-uploading later only adds new nights; existing nights are deduplicated.

Step 6: Put the card back

Eject the drive (Finder: eject icon; Windows: "Safely Remove Hardware").
Remove the card from the reader.
Slide it back into the machine, label-side as it came out, until it clicks.
Close the flap or cover.

If you forget to put the card back, the machine still records summary data internally, but those nights will have no waveforms.

How often to do this

Monthly suits most people; weekly if you are changing masks or settings. The card holds many months, so missing a cycle costs nothing.

FAQ

Questions people ask

Help center →

Can I remove the SD card while the CPAP is on?

Turn the machine off first and wait about 30 seconds for the screen to go idle. The machine writes to the card at the end of a session, and pulling the card mid-write can corrupt that night. With the machine off and idle, removing the card is safe and routine.

What size SD card does a ResMed AirSense use?

A full-size SD card, not microSD. Your machine shipped with one. If you need a spare, a standard SDHC card in the 4 to 32 GB range works; check with your DME before swapping, since the machine expects its folder structure. Never format the original.

Why does my computer say the SD card needs to be formatted?

Usually a reader or contact problem, not a damaged card. Click Cancel or Ignore, re-seat the card, try another port or reader. Formatting erases your data. If the card truly is unreadable in two readers, the data on it may be lost, but the machine will write new nights to a replacement card.

Can I read my CPAP SD card on my phone?

Not with Apnealytics today; card import is web-only. Some phones accept SD cards via an adapter and can show the files, but you still need a browser session on a computer to upload. The Apnealytics phone apps sync Apple Health / Health Connect and import CSV/JSON exports instead.

Does Apnealytics change anything on my card?

No. The upload reads the files and copies them to your private storage. Nothing is written to the card. Put it back in the machine and it continues exactly as before.