Leak pattern finder
When in the night your leak runs at its highest, read from your own nights.
Sample nights, made up for this page. They are no one's data.
Over your latest 30 nights with a leak reading, 389 of the 404 minutes your leak was at or above 24 L/min came in the final third of each night, on 27 nights in all.
Each row is one night, from its start on the left to its end on the right, with a mark at every minute at or above the line. ResMed sets its 24 L/min mask-seal line for the level a night's leak stays under 70% of the time. Here it marks single minutes, which is this site's own use of it.
Your answers are saved in this browser so you can come back to them. We record only which kind of read you got (for example, a pattern in the final third), never a leak figure or a date.
Related tools
What this tool does
Your machine and its app tell you how much your mask leaked on a night, as one number. That number does not say when the leak happened. This tool reads your nights minute by minute and asks one question: across your latest nights, do your highest-leak minutes keep landing in the same part of the night?
It runs in your browser on the nights you imported from your SD card. Choose sample nights to see what a found pattern looks like, or your nights to read your own. The same read lives on your History page and stays current each time you import.
How it reads your nights
It takes your latest 30 nights that carry a minute-by-minute leak reading, and needs at least 14 before it says anything. Each night is split into thirds by its own length, so a short night and a long night line up from start to end. Every minute at or above 24 L/min counts.
It names a third only when the minutes clearly bunch there: at least 60 minutes at or above the line in all, on at least 8 different nights, with 7 in 10 of them in one third. Then it gives the counts themselves, so you can see how strong the pattern is, and draws every night as a row with a mark at each of those minutes.
Those bars were set by testing the read on real SD cards contributed to this site, against copies of the same nights with each night's leak shifted to a random point. Read this way, it named a part of the night clearly more often on real nights than on the shifted copies, which is why it is shown. Four other shapes, tested the same way (leak starting at the same hour every night, leak breaks at the same clock time, leak that follows pressure, and leak that creeps up week by week), fired about as often on the shifted copies, or had too few long cards to test, so they are not shown.
About the 24 L/min line
24 L/min is the figure in ResMed's mask-seal line. ResMed sets it for the level a night's leak stays under 70% of the time, which is a statement about a whole night. This tool uses the same figure to mark single minutes, which is its own use of it, not a rating ResMed gives a minute.
Because the figure is ResMed's, the read runs on ResMed machines only for now. Other makers report leak on their own scales, and a line from one brand does not carry over to another.
What it does not tell you
It does not say why your leak is high in that part of the night, and it does not judge your mask or your therapy. A pattern is a set of counts from your own data. A night with no pattern is not a sign that your leak was low: leak that ran high all night long is spread across every third and shows nothing here.
If the counts surprise you, they are worth showing your equipment supplier or provider, who can look at your mask and your machine's full data with you. The common reasons for leak, each with its source, are in our guide to mask leaks.
Frequently asked questions
What does the leak pattern finder show?
It looks at your latest 30 nights with a leak reading, minute by minute, and counts the minutes your leak was at or above 24 L/min. When at least 7 in 10 of those minutes fall in the same third of the night (the first, middle or final third of each night's own length), it names that third and gives the counts.
Why does it only read ResMed machines?
The 24 L/min figure is ResMed's own, and other makers measure and show leak on their own scales. A line borrowed from one brand does not mean the same thing on another, so the read refuses other machines rather than guess. It may read more machines once each brand's own line has been tested on real cards.
Why does it sometimes show nothing?
It only names a part of the night when the minutes clearly bunch there: at least 60 minutes at or above the line, on at least 8 nights, with 7 in 10 of them in one third. Leak that is spread through the night, or too rare to place, shows nothing, and that is not a statement that your leak was low.
Does it tell me why my mask leaks?
No. It shows where in the night your leak minutes fall and the counts behind that, nothing more. The reasons a mask leaks, and what people try for each, are in our guide to mask leaks, and your equipment supplier or provider can look at your mask with you.
Is my data uploaded?
No. Your nights are read in your own browser from the SD card data you imported. Nothing about your nights leaves your computer.
Related Reading
- Why Your CPAP Mask Leaks and How to Fix ItWhy masks leak and what people try, with sources.
- Why myAir Hours Don't Match Your SD CardWhy your SD card shows more than your app does.