This watch will tell you if you’re suffering from sleep apnoea

The ScanWatch from Withings monitors blood oxygen saturation levels (SpO2) to detect whether wearers suffer from sleep apnoea syndrome – a temporary breathing disorder that leads to oxygen deficiency. — Withings/dpa

The problem with breathing disturbances like sleep apnoea is that it's almost impossible to tell you have them – because you sleep through the telltale symptoms.

But that's where one new high-tech watch promises to help by letting you keep track of your heart rate and rhythm both day and night.