[angrais]

This really depends on what you want to measure and if you want medical grade equipment. While other commenters have mentioned Garmin, there's also Fitbit Sense which offers EDA, ECG, SPO2 and other biopotential -- Great app too.

In the medical/research sphere I would recommend Empatica, but it is quite expensive:

- https://www.empatica.com/en-gb/

Also, recording ECG on the wrist is not ideal. Other alternative placements are the biceps and of course the chest. There are specific sensing devices that measure what you're interested in that cover both locations, but inccur larger cost than Fitbit.