Philips System One Data Guide

A lot of people are still sleeping with a Philips Respironics System One. It is the generation that came before the DreamStation, and many of these machines have been running every night for ten years or more. All that time, the machine has been writing a detailed record of each night to its SD card, and most owners have never seen it.

CPAP Clarity reads a System One 60 Series card entirely inside your web browser. Nothing is uploaded. This guide covers which System One models it reads, what the card holds, how to import it, and how to make sense of the numbers most owners care about: usage, AHI, pressure, and leak.

A Plain Note on the 2021 Recall First

Philips Respironics announced a recall in 2021 related to the sound-abatement foam used in many of its sleep therapy machines. Its recall notice lists SystemOne (Q series) devices among the affected CPAP machines, along with the original DreamStation. Whether your own machine is affected depends on its model and serial number, which the recall page lets you check.

This article is for people who already own a System One and want to understand the data it records. It is not a recommendation to keep, remediate, or replace any device. Those decisions belong to you and your clinician, using current information from Philips.

If you have not checked your own machine, the manufacturer keeps an official page where you can look it up. Start there, and talk to the clinician who manages your therapy:

Philips Respironics recall notice and device check (official)

CPAP Clarity does not sell devices, does not link to a replacement, and earns nothing from what you decide. We only help you read what your current machine already wrote.

For a shorter overview of what CPAP Clarity shows for this machine, see CPAP Clarity for the Philips System One.

Which System One Do I Have?

The System One came in two generations. The newer one is the 60 Series, and that is the one CPAP Clarity reads. The model number on the label underneath the machine tells you which you have.

60 Series: the middle digit of the model number is a 6, as in the REMstar Pro 460P and REMstar Auto 560P. A "BT" on the end (560PBT) means built-in Bluetooth and is the same machine underneath. The BiPAP Pro 660P and BiPAP Auto 760P are 60 Series too; their cards import usage and events, but leak is not measured on them yet.
50 Series: the middle digit is a 5, as in the 450P, 550P, 650P and 750P. These write an older version of the card format that CPAP Clarity does not read yet.

The REMstar Pro 460P is the model CPAP Clarity has checked night by night against OSCAR on a real contributor's card: usage on all 2,578 nights across about fourteen years, and event counts on the 2,310 nights that recorded events, with no night out of tolerance. The AHI matches OSCAR's on all but two of those nights. On those two, part of the night's therapy had no event record, and CPAP Clarity divides the events by the hours that were recorded, where OSCAR divides them by the whole night. The other 60 Series models write the same format and import through the same reader, but their numbers have not been cross-checked on a real card yet. If you own one and are willing to share your card, that is exactly what lets us confirm it.

If your card comes from a 50 Series machine, CPAP Clarity will tell you it cannot read it yet rather than showing you wrong numbers. The import screen offers a way to send the card in so support can be added.

What the System One Records

Every night, a 60 Series System One writes a detailed log to its SD card. That log includes:

Usage hours. How long you wore the mask with therapy running. This is the number insurers and the Medicare adherence rule care about most.

AHI (Apnea-Hypopnea Index). Events per hour of use. The machine scores the underlying events itself: obstructive apneas, clear-airway (central) apneas, hypopneas, RERAs (respiratory-effort-related arousals), flow limitation, and vibratory snoring. CPAP Clarity puts each scored apnea, hypopnea and RERA on your timeline with its own time.

Therapy pressure. A REMstar Pro runs a fixed prescribed pressure, while a REMstar Auto adjusts its pressure through the night. Either way, the machine also records the pressure it actually delivered every couple of minutes. With C-Flex or C-Flex+ turned on, that delivered pressure sits a little below the prescription, because Flex eases pressure as you breathe out. CPAP Clarity shows your median and 95th-percentile pressure from those readings.

Mask leak. The machine records total leak. CPAP Clarity subtracts the air your mask is designed to vent at that pressure, the same way OSCAR does, and shows what is left: the part that escaped your seal.

A flow waveform. A breath-by-breath trace of airflow, which is the raw signal the machine uses to score events. On the card we validated, 5,362 of its 6,234 sessions (86%) carried one, across all its years rather than just the last few weeks.

Your settings. Mode, pressure, ramp time and starting pressure, Flex type and level, and humidifier level, read from the card itself.

Reading these together is more useful than any single number. A low AHI with a high leak tells a different story than a low AHI with a good seal. For the wider picture of what AHI is and is not, see What Is AHI?.

Years of History on One Card

A System One card can hold a remarkable amount of history. The card we validated against held about fourteen years of nights. The machine keeps adding to it until the card is cleared, so on an older machine you may find several years of therapy waiting for you.

You may also notice folders named Clear0, Clear1 and so on next to the main device folder. Those appear when the card was cleared, for example with Philips' Encore software at a provider's office, and they hold sessions from before the clear. CPAP Clarity reads them with everything else; a session written in more than one folder is read once.

There may also be gaps. If the machine sat in a closet for a year, or the card was out of the machine, those months simply will not be there. A gap on the card is not a fault in the import.

Step 1: Eject the SD Card Safely

Turn the System One off and unplug it from the wall first, so a session is not half-written when the card comes out.

The SD card slot is on the side of the machine. Press the card in gently and let it spring out, then pull it free. You will put it back when you are done, and the machine keeps recording exactly as before.

Step 2: Connect the Card to Your Computer or Phone

Slide the card into the built-in card reader on your laptop, or use an inexpensive USB SD reader if your computer has no slot. On a phone, a USB-C or Lightning SD reader works the same way.

iPhone and iPad on iOS 17 or newer can select the whole card folder in Safari, and Android phones do the same in Chrome. A card with many years on it is large, often a few hundred megabytes, so a computer is the more comfortable choice for a first import. If a reader or browser does not cooperate, try a different one before assuming the card is the problem.

Step 3: Import It Into CPAP Clarity

Open cpapclarity.com and find the import zone on the home page. Select the entire SD card, or the P-Series folder on it. Do not open the folder named after your serial number and select that, because CPAP Clarity looks for P-Series in the path to recognize a Philips card.

Everything happens inside your browser. The reading, the math, and the charts all run on your own device, and no night of data is uploaded anywhere. Our CPAP data privacy explainer covers how and why the processing stays local.

A card with many years on it takes a little longer to read than a new one. When the import finishes, your dashboard opens on your most recent night, with every night on the card in your history.

How to Read Your Numbers

Here is how to make sense of the four numbers most System One owners look at, framed as observations to bring to your provider rather than instructions to act on.

Usage Hours

This is how long you wore the mask with therapy running. The adherence benchmark used by Medicare and many private insurers is at least four hours a night on at least seventy percent of nights across a thirty-day window. More time on therapy is generally better than less, but your own target is a clinical question. If your usage looks short and you are not sure why, comfort is a common cause and worth raising with your provider.

AHI and Its Components

An AHI under 5 is the range the AASM associates with well-controlled CPAP, a figure from its in-lab titration guideline (opens in new tab) rather than a home therapy target. Consistently above that, or a clear change from your own normal, is worth raising with the clinician who manages your therapy.

The components matter as much as the total. Obstructive apneas and hypopneas are the events CPAP is designed to address. A meaningful and lasting share of clear-airway (central) apneas is a different pattern, and it is one to flag rather than interpret on your own. The article on central versus obstructive apnea explains why. Flow limitation and RERAs are subtler signs of partly restricted breathing; understanding flow limitation covers them.

Pressure

On a REMstar Pro set to a fixed pressure, the number to look at is the pressure the machine actually delivered, which Flex lowers slightly as you breathe out. CPAP Clarity shows your median and 95th percentile. On a REMstar Auto, the same two numbers show where the machine usually settles and how high it reaches. A machine that spends most nights near the top of its allowed range is a pattern to discuss with your provider.

Never change your prescribed pressure or its limits yourself. Pressure belongs to the clinician who has your full medical context, not to any data tool. If you want background on how pressure is set in the first place, see CPAP pressure settings.

Some nights on a long card, recent ones included, show no pressure and no AHI at all. That happens when the machine kept only the summary of a night, without the readings and events it records during it: on the card we validated, 268 of its 2,578 nights. CPAP Clarity shows those nights with their usage and marks their AHI and pressure as not recorded, rather than inventing numbers.

A night can also be only partly recorded: one part of the night has the events, another has only a summary. CPAP Clarity then works out that night's AHI, pressure and leak over the recorded hours, because hours with no record are not hours with no events. It lists those nights by date when you import the card, and the night itself, in History, the therapy report and Copy for AI, says how many of its hours were recorded. If less than two hours were recorded, the night's AHI is not scored at all, the same two hours CPAP Clarity needs before it rates any night, because a short stretch cannot give a fair events-per-hour figure.

Leak

Leak is air escaping the mask seal. A small, steady leak is normal, because masks are vented by design. The concern is a large or spiky leak, which can hide events and make every other number less trustworthy. If your leak runs high on the nights your AHI looks worse, that is often the first thread to pull, and our guide to fixing CPAP mask leaks is a good next stop.

When to Talk to Your Doctor

CPAP Clarity is an informational tool, not a diagnostic one. It helps you see your own data. It does not tell you what is wrong or what to change. Bring your numbers to the clinician who manages your therapy if you notice patterns like these across several nights, not just one:

AHI consistently above 5 even on nights with solid usage hours.
A rising or lasting share of clear-airway (central) apneas.
Pressure pinned near the top of its allowed range night after night.
Large or spiky leak that lines up with your worse nights.
Daytime sleepiness that returns even when the numbers look fine.

Separately from the data: if you have not checked your machine against the 2021 recall, that is a conversation for Philips and your clinician, using current official information.

Keeping a Copy of Your Data

Once your data is in the browser, it lives in that browser's storage on that device. If you switch computers, clear your browser, or simply want a safety copy, you can export a backup file and re-import it later. The backup your CPAP data guide walks through it. The card itself is also worth keeping safe: if you ever replace the machine, the old card is the only record of those years.

If you already use the free desktop program OSCAR, it reads System One cards too, and it is a reasonable cross-check if you ever want to confirm a figure. CPAP Clarity's System One reader was built and checked against OSCAR's own reading of a real card.

If you also own a DreamStation, or move to one later, the Philips DreamStation data guide covers that machine's card the same way.

Frequently Asked Questions

Can I read my Philips System One data for free?

Yes. CPAP Clarity reads a System One 60 Series SD card for free, with no account and no upload. The reading runs inside your web browser on your own device, so your therapy data never leaves your computer or phone.

Which System One models does CPAP Clarity read?

The 60 Series, with model numbers like 460P and 560P (the BiPAP 660P and 760P import without leak). The REMstar Pro 460P has been checked night by night against OSCAR on a real card. The older 50 Series (450P, 550P and similar) uses an earlier format that CPAP Clarity does not read yet.

Which folder on the SD card holds the System One data?

Nightly logs live in a folder named after your machine's serial number, inside a folder named P-Series. Import the entire card, or the P-Series folder, so CPAP Clarity can find the device files and every night at once.

What are the Clear0 and Clear1 folders?

They appear when the card was cleared, for example with Philips' Encore software at a provider's office, and they hold sessions from before the clear. CPAP Clarity reads them along with the rest of the card, and a session written in more than one folder is read once.

Why do some nights show no pressure or AHI?

On some nights the machine kept only a summary, without the readings and events it records during the night. CPAP Clarity shows those nights with their usage and marks their AHI and pressure as not recorded rather than guessing them.

Can I change my pressure based on what I see?

No. CPAP Clarity shows what your machine recorded so you can have a better-informed conversation, but pressure and other prescription settings should only be changed by the clinician who manages your therapy.

Get Started

Drop your System One SD card onto the CPAP Clarity home page to see your first dashboard. No account, no upload, and no data leaves your browser. If something in your numbers does not look right, the feedback page reaches a real person.

Further reading: