How to Read Your CPAP Data on iPhone (Without a Laptop)

· 6 min read · Written by a CPAP user
Woman enjoying a peaceful morning in bed, using her smartphone by a sunlit window

Your CPAP machine records detailed data about every single breath you take during the night. Respiratory events, mask leak rates, pressure adjustments, flow waveforms — it is all there, stored on a tiny SD card inside your machine. The problem? Most people never see any of it.

Manufacturer apps like ResMed’s myAir show you a simplified daily score and maybe a few surface-level stats. If you want the full picture, you have traditionally needed to pull out the SD card, find a laptop with an SD card slot, install desktop software, and try to make sense of clinical-looking graphs. For most CPAP users, that is simply too much hassle for a daily habit.

But what if you could just plug your SD card into your iPhone and see everything in seconds? That is exactly what CPAP Analysis does — and this guide walks you through the entire process.

What You Need

The setup is remarkably simple. You need three things:

1. Your iPhone

Any iPhone running iOS 17 or later will work. CPAP Analysis is designed for iPhone, taking full advantage of the screen size and processing power to render detailed charts smoothly.

2. An SD Card Adapter

This depends on which iPhone you have:

3. CPAP Analysis (Free)

Download CPAP Analysis from the App Store. The app is free to download.

Step-by-Step: Reading Your CPAP Data on iPhone

Step 1: Remove the SD Card From Your CPAP Machine

Power off your ResMed AirSense 11 (or wait until you are done sleeping). Open the small flap on the side of the machine and gently pull out the SD card. It is the same type of SD card used in cameras — a standard full-size SD card.

Do not worry about removing it. Your CPAP machine works perfectly fine without the SD card inserted. It simply will not record detailed data while the card is out.

Step 2: Connect the SD Card to Your iPhone

Plug your SD card adapter into your iPhone, then insert the SD card into the adapter. Your iPhone will recognise the card automatically — there is no pairing or setup process.

Step 3: Open CPAP Analysis and Import

Launch CPAP Analysis and tap the import button. The app will ask you to select the SD card from the Files browser. Navigate to the CPAP data folder (usually named something like “DATALOG”) and confirm.

CPAP Analysis reads every date folder on the card and imports your complete therapy history. Depending on how much data is on your card, this typically takes between 10 seconds and a couple of minutes.

Step 4: Explore Your Data

Once the import completes, you are in. The dashboard shows your most recent night with a detailed breakdown of everything that happened while you slept.

What Your CPAP Data Actually Reveals

This is where things get interesting. Your SD card contains far more information than your manufacturer app shows you. Here is what CPAP Analysis makes visible:

AHI Score With Context

Your Apnoea-Hypopnoea Index (AHI) is the headline number — it tells you how many breathing disruptions you experienced per hour of sleep. But unlike your manufacturer app, CPAP Analysis does not just show you a single nightly average. It calculates a rolling hourly AHI so you can see exactly when your breathing was worst during the night.

This matters because a nightly AHI of 3 might sound great, but it could be hiding two hours at AHI 15 sandwiched between six hours of clean breathing. The rolling view makes these patterns impossible to miss.

Event Timeline

Every respiratory event your machine detected — obstructive apnoeas, central apnoeas, hypopnoeas, and unclassified events — is plotted on a detailed timeline. You can see the exact time each event occurred, how long it lasted, and whether events clustered together.

This is the data that helps you and your sleep doctor identify patterns. Are your events concentrated in the early morning hours? That might suggest positional issues or REM-related breathing problems. Seeing a sudden cluster of central apnoeas? That is worth discussing with your doctor.

Leak Rate Tracking

Mask leak is one of the most common reasons CPAP therapy becomes less effective. Your SD card records detailed leak data throughout the night, and CPAP Analysis shows you exactly when leaks happened and how severe they were.

Small leaks are normal, but large leak spikes can mean your mask shifted, your mouth opened, or the seal broke during a position change. Identifying when leaks happen helps you troubleshoot mask fit without expensive sleep lab visits.

Pressure Data

If you are using an auto-adjusting CPAP (APAP), your machine constantly adjusts pressure throughout the night. The SD card records every pressure change, and CPAP Analysis shows you the pressure curve alongside your events and leak data.

Seeing pressure, events, and leaks together on the same timeline is powerful. You might notice that pressure increases always coincide with event clusters, or that a particular pressure level seems to trigger leaks.

Why iPhone Beats a Laptop for CPAP Data

You might wonder why reading CPAP data on an iPhone matters when desktop software like OSCAR has been available for years. Here is why mobile-first analysis changes the game:

It Becomes a Daily Habit

The single biggest advantage of iPhone-based CPAP analysis is consistency. When checking your data requires booting up a laptop, finding the SD card reader, waiting for software to load, and navigating a complex interface — most people do it once and never again.

When it takes 30 seconds with your iPhone on the bedside table, it becomes something you do every morning. And daily review is where the real insights emerge. You start noticing patterns: worse AHI on nights you drink alcohol, better numbers after changing your pillow, leak spikes that correlate with sleeping on your left side.

Your Data Stays Private

CPAP Analysis processes everything locally on your iPhone. Your sleep data never leaves your iPhone — we literally cannot see it. Your data stays on your device, under your control.

This matters because CPAP data is health data. It reveals your breathing patterns, your sleep schedule, and potentially sensitive medical information. Keeping it on your device is simply the right approach.

You Can Show Your Doctor Immediately

Having your complete CPAP data history on your phone means you are always prepared for doctor appointments. No need to remember to bring a laptop or print charts. Just hand your doctor your phone and let them scroll through your data.

The visual charts in CPAP Analysis are designed to be readable by both patients and clinicians. Your sleep doctor will immediately understand the rolling AHI chart, event timeline, and pressure data.

What About Other CPAP Machines?

CPAP Analysis works with most ResMed machines, including the AirSense 11 and AirSense 10. Because different manufacturers store data in different formats on their SD cards, we are expanding support one manufacturer at a time rather than offering half-baked support for everything.

If you use a different machine (Philips DreamStation, Luna, etc.), you can express your interest and we will prioritise accordingly.

Frequently Asked Questions

Do I need a special adapter, or will any SD card reader work?

For iPhone 15 and newer (USB-C), any standard USB-C to SD card reader will work — no special brand required. You can find them on Amazon for under £10. For iPhone 14 and older (Lightning), you need a Lightning-compatible SD card reader. Apple’s official “Lightning to SD Card Camera Reader” works reliably, though third-party alternatives are also available.

Will removing the SD card or importing data damage my CPAP machine or its data?

No. CPAP Analysis is a strictly read-only app. It reads the files on your SD card to build your charts but never modifies, deletes, or writes anything to the card. Your CPAP machine works normally without the SD card — it simply will not record detailed data while the card is removed. Pop it back in when you are done importing.

How often should I import my SD card data?

That is entirely up to you. Some users import daily as part of their morning routine — unplug, import, plug back in, done in under a minute. Others import weekly or before doctor appointments. Subscribe to get unlimited daily imports, so there is no cost to checking daily.

Start Reading Your CPAP Data Today

Your CPAP machine is generating rich, detailed data about your sleep every single night. That data belongs to you, and you deserve to see all of it — not just the simplified score your manufacturer app provides.

With an inexpensive SD card adapter and the free CPAP Analysis app, you can go from “I wonder what my data looks like” to scrolling through detailed charts in under a minute. No laptop. No complex software. Just your iPhone and the truth about your sleep.

Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor or sleep specialist with any questions about your CPAP therapy.

See Your CPAP Data on iPhone

Plug in your SD card, import in seconds, and explore rolling AHI, event timelines, and pressure charts — all on your phone.

Download Free on the App Store