Remember that all this have debates about accuracy and if they skip time periods. This is why the old school (medical) devices are still used. But for most folk these are fine.
I am looking for a wearable device as a watch that can register hearth rate continuously (all day long). If possible, the data would be registered in a smartphone app. I also need to be able to download the data to use them in Excel or Matlab. Do you know any product that matches my needs?
It would be perfect if the app in question is like an opensource app which doesn't send the data to some industry.
Thank you for your answer.