Best for non-invasive
Nokia Sleep, £100
Place this wireless pad under the bedsheet and it measures your pulse, restlessness and more; its app collates the stats and suggests a sleep training regime. It can also control smart-home functions such as heating and lighting.
Best for refund scheme
Dreem €499 (£440)
This headband sensor whispers calming messages to you via a bone-conducting headphone and is easiest worn if sleeping on your back. Big claims include 30% faster nodding off and 40% more “quality” sleep. Return it within 30 days and you’ll get a refund.