WORKS WITH · SUPPORTED, PRO

Contec CMS50 oximeters with CPAP data in Apnealytics

The Contec CMS50 family is the budget end of overnight oximetry: finger-clip and wrist units that have been sold under many brand names for over a decade. Apnealytics imports their CSV exports and overlays SpO₂ and pulse on your CPAP night, with ODI₃, ODI₄ and T90 in the summary. Using a Contec CMS50 with CPAP data is a Pro feature.

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A hand on a blanket with a finger clip oximeter on the index finger

CMS50 family at a glance

Spec	Contec CMS50 family
Models	CMS50D+ (finger clip with memory), CMS50E, CMS50F (wrist unit with finger probe), CMS50I (wrist, Bluetooth) and rebadged equivalents
Records	SpO₂ and pulse rate; some models add a pleth waveform
Sample interval	1 s on most recording models
Memory	One night or more on the device
Connection	USB cable to a computer; Bluetooth on some models
Software	Contec SpO2 Assistant or SpO2 Review for Windows; VitalSigns / ViHealth-type phone apps on Bluetooth models
Export	CSV from the desktop software or app
Apnealytics status	Supported, Pro

CMS50F wrist unit with finger probe and a CMS50D+ finger clip

Export the CSV

Connect the oximeter by USB and open Contec's software.
Download the recorded session from the device.
Open the session and choose Export, then CSV.
Save the file somewhere you can find it.

From a phone app (Bluetooth models)

Pair the oximeter and sync the session into the app.
Open the session and choose Share or Export, then CSV.
Share it to the Apnealytics app directly, or save it to Files or downloads.

The CSV has a timestamp, SpO₂ and pulse per row. Layouts vary between software versions and rebadged brands, so Apnealytics shows a column mapper the first time it sees an unfamiliar layout and remembers your choice.

Import into Apnealytics

On the web: at my.apnealytics.com, drop the CSV onto Import or open the night and choose Add oximetry.
On the phone: in the Apnealytics app, open the night, tap Add oximetry and pick the CSV.
Apnealytics aligns the session with your machine's clock by timestamp. CMS50 clocks drift, sometimes badly, so check the offset control on the night and nudge the dips onto the events if needed.

Older CMS50 software exports without a date, only a time of day. When that happens Apnealytics asks you to confirm which night the file belongs to.

What the overlay shows

Two traces, SpO₂ and pulse, above the airflow and event strip for the night. Each drop of 3 percent or more from baseline is marked; 4 percent drops are marked more strongly. Click a marker to zoom the Pro waveform viewer to that moment. The summary adds average and lowest SpO₂, average and highest pulse, ODI₃, ODI₄ and T90, trended across any range.

ODI and T90, briefly

ODI₃ and ODI₄ are desaturations per hour at 3 and 4 percent thresholds. T90 is the time below 90 percent SpO₂. They are the oximeter's view, separate from the machine's AHI, and the overlay shows where the two agree. Neither is a diagnosis. See SpO₂ explained.

SpO2 and pulse overlay with a marked dropout gap and ODI and T90 tiles

Known quirks

Finger clips come off. The CMS50D+ clip can loosen during sleep, producing a flat line or dropout. Apnealytics marks gaps rather than drawing through them. Many people tape the clip or prefer the wrist-and-probe CMS50F.
Clock drift. Set the device clock from the software before each night if your model allows it.
Rebadged units. The same hardware is sold under many names. If your CSV layout is not recognised, the column mapper handles it; send the file to info@apnealytics.com and we will add the layout.
Memory limits. Some models hold only one night. Download before you record again.

Pro note

Oximetry import and overlays are part of Pro at $8.99 a month or $99.99 a year, per account, covering every family login. See pricing.

FAQ

Questions people ask

Help center →

Which Contec CMS50 models work with Apnealytics?

Any model that records overnight and exports CSV: the CMS50D+, CMS50E, CMS50F, CMS50I and their rebadged equivalents. Export from Contec's desktop software or the companion app, then import on the web or in the phone apps. Oximetry overlays are a Pro feature.

My CMS50 CSV has no date column. What do I do?

Some older software versions export only time of day. Apnealytics detects this and asks which night the file belongs to; pick the date and the overlay aligns from there. Newer software versions include the date and need no prompt.

Can Apnealytics read the CMS50 directly over USB?

No. Browsers cannot read the device, and Contec's software is the step that pulls data off it. Export CSV from that software and import it. Bluetooth models that sync to a phone app can export CSV from the app and share it to Apnealytics in a few taps.

Is a CMS50 accurate enough to be useful?

It is a consumer oximeter, not a clinical one, and it is sensitive to movement and a loose clip. For spotting whether your events line up with desaturations across many nights it is useful; for any clinical question, talk to your clinician. Apnealytics marks motion and dropout so you can discount them.

CMS50 or O2Ring?

The CMS50 family is cheaper and widely available; the O2Ring is more comfortable and stays on more reliably. Both import into Apnealytics the same way. See the Wellue O2Ring page for its export steps.