WatchPAT Data Error — Recording Incomplete or Corrupted

What Does This Error Mean?

A data error on WatchPAT means the sleep recording is incomplete, has gaps, or the system has flagged too many signal artefacts for a reliable result. The study may need to be repeated.

Affected Models

WatchPAT ONE
WatchPAT 300
WatchPAT 200

Common Causes

Sensor fell off finger during the night
Too much movement during sleep (motion artefacts in the PAT signal)
Too few hours of valid data recorded (battery died or device started late)
Environmental interference with the optical sensor
Recording started before actual sleep time, giving insufficient sleep data

How to Fix It

Check if the sensor was on all night

After waking, check whether the finger probe is still in position. If it had fallen off, you will know when the data gap occurred.
Contact the clinic

Send or return the device to the clinic. A sleep technologist will review the recording and determine whether the captured data is sufficient for analysis.
Prepare for a possible repeat study

If the data is insufficient, the clinic will schedule a repeat night. This is common — roughly 10–15% of home sleep tests require a repeat.
Tips for a better recording next time

Use tape (provided with the device) to secure the probe to your finger. Start the recording just before getting into bed. Sleep on your back if possible — it reduces sensor displacement.

When to Call a Professional

Contact the prescribing clinic — they will review the data and advise if a repeat study is needed.

WatchPAT Data Recording Error

A WatchPAT recording can fail to provide usable data for several reasons, most of which are related to sensor placement and probe security during sleep.

The Most Effective Prevention

Secure the probe with the adhesive tape provided in the device kit. The tape gently holds the probe to your fingertip throughout the night, preventing it from sliding off when you move in your sleep.

When a Repeat Study Is Needed

Your sleep physician needs at least 4 hours of clean signal to make a reliable sleep apnea assessment. If the data shows less than this — or if too much of the signal is marked as artefact — a repeat is needed.

This is a common occurrence in home sleep testing and is nothing to worry about. The repeat study is done under the same conditions, usually within a week or two.

Frequently Asked Questions

How common is it to need a repeat WatchPAT study?

Repeat rates for home sleep tests are estimated at 10–20%. This is not unusual and is not a reflection of doing anything wrong. Securing the probe with the provided adhesive tape significantly reduces the chance of a repeat.

Will I need to pay again for a repeat WatchPAT study?

This depends on the clinic, your insurance, and the reason for the repeat. If the device failed or the probe fell off due to poor device design or a faulty unit, the clinic typically provides a repeat at no extra cost. Ask your clinic directly.