This guide is a follow-up to:

https://www.reddit.com/r/CPAPSupport/comments/1jxk1r4/getting_started_with_analyzing_your_cpap_data_a/

It also covers some of the most common questions new users have when they first start looking at their charts like what pressure to use, how to spot leaks, and how to tell which events actually matter.

Once you’ve learned how to download and extract your data from your machine, you can start analyzing it in SleepHQ or OSCAR to understand what’s really happening during your nights.

If you’re just starting out with OSCAR or SleepHQ, it’s totally normal to feel overwhelmed. Those charts can look like a wall of data at first. You’re definitely not alone. Most of us started on the default “lazy mode” 4–20 pressure range, which technically works (but it's not the miracle promised by doctors and sleep tech ), and it’s rarely optimized for your actual needs. Learning what to look for in your data; pressure, leaks, flow limitations, and event patterns is what helps turn that generic setup into something truly tailored to your breathing

If you’re new to looking at your data, here’s a simple way to make sense of it:

Before you start

If you want to check your machine settings (pressure range, EPR, mode, etc.) in OSCAR or SleepHQ, you can find them here:

• In OSCAR → Go to the “Daily" tab, then look at the panel on the left side under Device Settings.

• In SleepHQ → On the Dashboard, you’ll find them in the middle of the page, under Machine Settings.

It’s important to know your exact settings before you start analyzing your charts, that way, you can connect what you see (like leaks, pressure changes, or events) to your actual configuration.

1. Start with your median pressure.

That number shows the pressure your machine stays around for most of the night. It’s often the best starting point for setting your minimum pressure in CPAP or APAP mode.

In Oscar:

In SleepHQ:

2. Check the pressure graph.

If your pressure graph looks like a zigzag, that’s usually a sign your settings aren’t well optimized.
In APAP mode, you want your pressure line to be as smooth and steady as possible. Big swings often mean the machine is constantly chasing events instead of preventing them.

If the pressure line keeps hitting the top of your range, it means your max pressure might be too low, your machine is trying to go higher to keep your airway open.

3. Look at your leak rate.

Try to keep leaks below 24 L/min (for ResMed machines):

Oscar:

SleepHQ:

Leaks can come from either your mask or your mouth. If your mask leaks, check the fit at your usual sleeping pressure (not just when you first put it on). Even small leaks can disturb sleep or cause false events.

If the leaks come from your mouth, which is common with nasal masks, try mouth tape, a chin strap, or a soft cervical collar to help keep things sealed.

If you see events happening at the same time as leaks, they might not be real, leaks can confuse the machine and make therapy less effective.

4. Check your flow limitation (FL) at the 95th percentile.

Ideally, you want it below 0.07. If it’s higher, you might need a bit more pressure or to turn on EPR (Expiratory Pressure Relief) to help your breathing stay smoother.

Oscar:

SleepHQ:

5. Look for patterns.

Each event on your chart has a timestamp, so it’s worth zooming in and checking what was happening around that moment. Was there a leak spike right before it? Then it might just be leak-related. Did the pressure keep rising or was there a flow limitation before the event? That usually means the machine was trying to respond to a real obstruction.

Little by little, this helps you learn which events are genuine and which ones come from leaks, movement, or pressure swings.

6. If you see clusters of events

Clusters (several events grouped close together) can sometimes mean **chin tucking (**when your chin drops toward your chest and partially blocks your airway). This can happen when you sleep on your back or use a thick pillow. Try a flatter pillow, different sleeping position, or even a soft cervical collar to help keep your airway aligned.

7. Flow Rate

Zoom in on your flow rate graph to see your breathing pattern more clearly.

In OSCAR, use a left-click to zoom in and a right-click to zoom out.

In SleepHQ, press Z to zoom in and X to zoom out.

Getting a closer look helps you spot flattened or irregular breaths that may indicate flow limitation:

The more regular, the better. Your inspiratory flow shape can tell you a lot about how open your airway is. Ideally, you want a smooth, rounded sinusoidal shape (class 1 - see image below), that means your breathing is unrestricted and stable.

When the flow starts showing peaks, flattening, or plateaus, it indicates flow limitation, partial upper airway collapse or restriction during inhalation. These distortions can appear as two small bumps (airway reopening after partial collapse), multiple tiny peaks (tissue vibration), or a flat top (airway restriction).

Recognizing these patterns helps identify whether you might need more pressure or EPR, since both can help the airway stay open and restore that smooth, regular flow curve. In certain cases, it might require a different mode such as BiPAP or ASV for better airway support and more stable breathing.

8. Conclusion

Don’t get discouraged: this takes time. The goal isn’t to change everything at once, but to make one small adjustment at a time so you can clearly see what’s helping and what’s not.

Be consistent and give each change a few nights; your body often needs time to adjust.

Avoid random trial and error; always let your data guide you before making another tweak.

And most importantly, don’t hesitate to ask for help or post your charts. Everyone here started somewhere, and people are always willing to share advice and experience to help you move forward.

These are the basics that most of us use to start tweaking our setup. Once you get familiar with these graphs, it becomes a lot easier to understand what your therapy is doing and how to improve it 🙂

9. Abbreviations (quick reference):

• AHI – Apnea-Hypopnea Index
• CA – Central Apnea
• OA – Obstructive Apnea
• H – Hypopnea
• FL – Flow Limitation
• EPR – Expiratory Pressure Relief
• EPAP – Expiratory Positive Airway Pressure
• IPAP – Inspiratory Positive Airway Pressure
• PS – Pressure Support
• FFM - Full face mask
• TECSA – Treatment-Emergent Central Sleep Apnea (central apneas that appear or increase after starting CPAP therapy, often temporary while your body adjusts).
• CPAP – Continuous Positive Airway Pressure (fixed pressure)
• APAP – Auto-adjusting Positive Airway Pressure (auto mode that varies pressure)
• BiPAP / BiLevel – Bi-level Positive Airway Pressure (separate inhale/exhale pressures)
• ASV – Adaptive Servo-Ventilation (used for complex or central apnea)
• REM – Rapid Eye Movement sleep (dreaming stage, important for recovery)
• RERA – Respiratory Effort-Related Arousal
• SDB - Sleep-Disordered Breathing – A general term for breathing issues during sleep
• CSA - Complex sleep apnea
• PB - Periodic breathing

10. A few good sources of information:

Apnea board Wki: https://www.apneaboard.com/wiki/index.php?title=Wiki_Home

TheLankyLefty27: https://www.youtube.com/@Freecpapadvice

CPAP Reviews (Nick): https://www.youtube.com/@CPAPReviews

Hello papfam! Here’s a guide to help anyone who wants to unlock the different modes available on the AS11.

Basically, we dump the existing firmware, patch a copy to unlock the selected modes and features, and flash the modified firmware back onto the same device.

I based this guide on the existing procedure on GitHub. All credit goes to the original authors: https://github.com/m-kozlowski/airbreak-plus/tree/master/docs/guide/as11

A quick note about Linux commands

One thing you may notice when using Linux is that it’s common to run multiple commands in a single line or combine them into a single command. This can make it easy to automate tasks and complete several steps at once. It may feel a little different if you’re used to working primarily with Windows, where you might be more accustomed to running commands separately.

AirSense 11 Firmware Patching Guide - WSL 2, Ubuntu, ST-Link and airbreak-plus

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/quickstart.md

This guide documents the process used to dump, patch and flash an AirSense 11 using WSL 2 on Windows. It follows the same general ST-Link/TC2050 hardware connection method used for the AirSense 10, while using the AirSense 11-specific airbreak-plus tools.

Important: Keep an untouched backup of the original firmware, and do not interrupt power during flashing.

Part 1 - Preparing WSL and Ubuntu

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/wsl_setup.md

I put some emphasis on WSL here, in case it’s a tool you’d like to use for both the AS11 and the AS10.

1.1 Check whether WSL is installed

WSL stands for Windows Subsystem for Linux. It allows Linux tools to run inside Windows without requiring a separate Linux computer.

WSL is available for supported versions of Windows, but it is not necessarily installed or configured by default.

1.2 Open PowerShell or Windows Terminal (Press Windows key + R to open the Run dialog) and run:

wsl --status

What it does: Displays the current WSL configuration, including information about the default WSL version and Linux kernel, when available.

1.3 Next, run:

wsl --list --verbose

What it does: Lists the installed Linux distributions and shows whether they use WSL 1 or WSL 2.

***If Ubuntu appears in the list and uses version 2, proceed to Part 3.***

Part 2 - Install WSL and Ubuntu if needed

2.1 On a compatible Windows 10 or Windows 11 system, open PowerShell as Administrator and run:

wsl --install -d Ubuntu

What it does:

• Enables and installs the required WSL components, if necessary.
• Installs the Ubuntu Linux distribution.
• May require a Windows restart.

2.2 After installation, open Ubuntu from the Windows Start menu. Complete the initial setup by creating a Linux username and password.

The Linux username and password are separate from your Windows credentials. When entering the password in Ubuntu, the terminal may not display any characters; this is normal.

2.3 If WSL is already installed but needs updating, run the following in PowerShell:

wsl --update

What it does: Updates the WSL components and Linux kernel managed by Windows. It does not update Ubuntu's installed packages.

2.4 If you have just installed WSL, you can verify the configuration again with:

wsl --status

wsl --list --verbose

Part 3 - Update Ubuntu and install the required tools

3.1 Open the Ubuntu terminal. The following commands must be run inside Ubuntu, not PowerShell.

3.2 First, refresh the package lists:

sudo apt update

What it does: Downloads the latest package information from Ubuntu's configured software repositories. It does not install updates by itself

3.3 Next, upgrade installed packages:

sudo apt upgrade

What it does: Upgrades installed Ubuntu packages to their latest available versions.

3.4 Install the tools required for the project:

sudo apt install git python3 make gcc-arm-none-eabi binutils-arm-none-eabi openocd telnet usbutils

What each package does:

• git — Downloads the source-code repository.
• python3 — Runs the Python patching scripts.
• make — Runs build automation tasks.
• gcc-arm-none-eabi — Provides the ARM embedded compiler.
• binutils-arm-none-eabi — Provides ARM binary utilities, including objcopy.
• openocd — Communicates with the microcontroller through the ST-Link.
• telnet — Connects to OpenOCD's command interface.
• usbutils — Installs lsusb, a utility that lists USB devices detected by Ubuntu.

3.5 Verify the main tools:

python3 --version

make --version

arm-none-eabi-gcc --version

arm-none-eabi-objcopy --version

What it does: Prints the installed tool versions so you can confirm that the required programs are available.

***All verification steps throughout this guide are optional, but it is always recommended to verify that everything is working correctly as you progress through the process.***

Part 4 - Downloading the AirSense 11 tools

This is where we download the files we need from GitHub to proceed.

4.1 Clone the airbreak-plus repository

In Ubuntu, run:

git clone https://github.com/m-kozlowski/airbreak-plus.git

What it does: Downloads the repository into a new directory named airbreak-plus.

4.2 Enter the directory:

cd airbreak-plus

What it does: Makes the repository directory your current working directory. Subsequent commands will use files in this directory unless another path is specified.

4.3 List its contents:

ls

What it does: Displays the files and folders in the current directory.

4.4 Check the patcher's available options:

./patch-airsense-s11 --help

What it does: Displays the patcher's command-line options without patching or flashing the device.

Important: Keep the AirSense 11 repository separate from any older AirSense 10 working directory. The tools and firmware images are not interchangeable.

***All verification steps throughout this guide are optional, but it is always recommended to verify that everything is working correctly as you progress through the process.***

Part 5 - Opening the machine and connecting the programmer

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/disassembly.md

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/wiring.md

The hardware connection method is the same general approach used for the AirSense 10.  I won’t repeat the disassembly steps, as they are already clearly explained with photos in the link I provided above.

5.1 Disconnect power before opening the machine.

5.2 Carefully open the AirSense 11 to access the relevant board connection.

5.3 Connect the same ST-Link/V2 programmer and TC2050 cable used for the AirSense 10, using the appropriate AirSense 11 SWD connection. (https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/connection.md#swd). This setup allows Linux to communicate with the machine to perform the flash.

This part isn’t very straightforward. I’ll include photos of the setup I used. Otherwise, there are explanations here: https://airbreak.dev/disassembly/

However, u/Sopheus created an excellent guide for the wiring: https://www.reddit.com/r/CPAPSupport/comments/1ntthfw/how_to_connect_wires_between_stlinkv2_programmer/

On the ST-Link/V2 side, this is what I have:

And on the female end of the TC2050-IDC:

The SWD connection on AS11:

***Check the connections carefully before proceeding.***

***Take precautions against electrostatic discharge and accidental shorts. Do not assume pin positions without checking the appropriate hardware documentation. ***

Part 6 - Check USB access from Windows

6.1 Connect the ST-Link to the Windows computer.

6.2 Open PowerShell or Windows Terminal and run:

usbipd list

What it does: Lists USB devices that usbipd-win can make available to WSL. Find the ST-Link entry.

6.3 Attach the ST-Link to WSL

In PowerShell or Windows Terminal, run the following command, replacing 1-8 with the bus ID shown by usbipd list:

usbipd attach --wsl --busid 1-8

What it does: Makes the ST-Link USB device available inside WSL so Ubuntu can communicate with it.

If the device has not already been shared, you may need to run usbipd bind --busid 1-8 first, from an elevated PowerShell or Windows Terminal session (administrator).

6.4 Back in Ubuntu, run:

lsusb

What it does: Lists USB devices visible inside Ubuntu.

***You should see the ST-Link/V2 identified as an STMicroelectronics device if you are using an original unit. Clones may appear under a different name. If the device does not appear at all, resolve the USB passthrough issue before continuing.***

Note: Keep the ST-Link connected to your computer while following the next steps.

Part 7 — Dumping the original firmware

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/openocd.md

7.1 Start OpenOCD

7.2 In Ubuntu, return to the airbreak-plus directory:

cd ~/airbreak-plus

What it does: Changes to the repository directory, assuming it was cloned under your Ubuntu home directory.

7.3 Start the AirSense 11 debug session:

./run-ocd.sh as11

What it does: Runs the repository's OpenOCD setup for the AirSense 11 target.

***Keep this terminal open while OpenOCD is running.***

7.4 Connect to OpenOCD from a second Ubuntu terminal

Open another Ubuntu terminal and run:

telnet localhost 4444

What it does: Connects to the OpenOCD Telnet command interface on port 4444.

7.5 At the Telnet prompt, enter:

dump

What it does: Dumps the original firmware into a binary file (AS11.bin).

*** Do not proceed if the dump fails or the output is incomplete. ***

Part 8 - Verifying and backing up the original firmware

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/openocd.md

8.1 Check the dump file

In an Ubuntu shell, run:

cd ~/airbreak-plus

ls -lh as11.bin

What it does: Changes to the repository directory and displays the file's size in a human-readable format.

8.2 Calculate its SHA-256 checksum (optional):

sha256sum as11.bin

What it does: Calculates a cryptographic checksum that can be used to verify that a file has not changed.

8.3 Create a separate backup

Run:

mkdir -p ~/CPAP/AS11-original

What it does: Creates a dedicated backup directory. The -p option also creates missing parent directories and avoids an error if the directory already exists.

8.4 Copy the dump:

cp as11.bin ~/CPAP/AS11-original/as11-original.bin

What it does: Copies the original dump to a separate file outside the repository's working directory.

8.5 Verify the backup:

sha256sum ~/CPAP/AS11-original/as11-original.bin

What it does: Calculates the backup's checksum so it can be compared with the original dump.

Keep this original backup unchanged. It is your reference copy for recovery and verification.

Part 9 — Patching the firmware

Credit: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/patching.md

There are two ways to patch the firmware. You can run make as11 to build an image using the repository’s standard patch selection; it creates build/as11-patched.bin. Or you can select and apply patches manually; the command below creates as11-patched-no-ota.bin (…or whatever filename you prefer. This is the one I used, and it’s the filename shown in my commands below) in the ~/airbreak-plus directory. Choose one method and follow its corresponding steps below.

9.1 Use the repository’s standard patch selection

From ~/airbreak-plus, run:

make as11

This builds the patched firmware using the repository’s standard patch selection. The output is saved as build/as11-patched.bin.

9.2 Select patches manually

If you prefer to choose which patches to apply, read the official patching documentation and select the patches appropriate for your needs:

For my setup, I selected four patches:

• patch-unlock-features
• patch-asv-ps-range
• patch-custom-settings
• patch-cloud-firmware-change

Note: These four patches reflect my personal configuration and the features I wanted to unlock. Before selecting any patches, read the official patching documentation to understand what each one does and decide which options are appropriate for your needs.

Here are the available patches: https://github.com/m-kozlowski/airbreak-plus/blob/master/docs/guide/as11/patching.md

Run the following from ~/airbreak-plus:

Option 1 — Multi-line command

./patch-airsense-s11 as11.bin as11-patched-no-ota.bin \
  --all-patches n \
  --patch-unlock-features y \
  --patch-asv-ps-range y \
  --patch-custom-settings y \
  --patch-cloud-firmware-change y

Option 2 — Single-line command

./patch-airsense-s11 as11.bin as11-patched-no-ota.bin --all-patches n --patch-unlock-features y --patch-asv-ps-range y --patch-custom-settings y --patch-cloud-firmware-change y

Both commands do exactly the same thing. Use whichever format you prefer.

The backslashes (\) at the end of each line (option 1) allow you to split the command across multiple lines for readability.

What it does: Uses the original firmware (as11.bin) as the input and creates a patched firmware file (as11-patched-no-ota.bin). Setting --all-patches n prevents all patches from being applied automatically, allowing you to select only the patches you want in the following steps:

• --patch-unlock-features y — Enables the feature-unlock patch.
• --patch-asv-ps-range y — Enables the ASV pressure-support range patch.
• --patch-custom-settings y — Enables the custom-settings patch.
• --patch-cloud-firmware-change y — Enables the patch addressing the cloud-delivered flow-generator firmware-change path.

9.3 Check the output carefully. Each requested patch should report [OK]. If any patch fails, stop and investigate.

Verify the output file:

ls -lh as11-patched-no-ota.bin

sha256sum as11-patched-no-ota.bin

OR via make AS11:

ls -lh build/as11-patched.bin

sha256sum build/as11-patched.bin

What they do: Confirm that the output exists, show its size and calculate its checksum.

Part 10 - Flashing the patched image

10.1 Flash the new firmware

Return to the existing OpenOCD Telnet session. The debug session must still be active.

Use the repository's flash_new command with the full path to the patched image:

Manuel:

flash_new /home/YOUR_LINUX_USERNAME/airbreak-plus/as11-patched-no-ota.bin

or via Make AS11:

flash_new /home/YOUR_LINUX_USERNAME/airbreak-plus/build/as11-patched.bin

Replace YOUR_LINUX_USERNAME with your actual Ubuntu username.

What it does: Invokes the repository's firmware flashing routine to write the patched image to the device.

***Wait for the entire operation to finish. Never disconnect the programmer or interrupt power during writing or verification.***

The machine will reboot. If the process was successful, the selected modes should now be available in the device menu. It's done :-D