Watches and blood thinners

My husband is on blood thinners, currently uses a Garmin GPS watch when walking. He is so sensitive that pushing the buttons on the side of the Garmin causes his skin to bruise quite a bit. So my questions......

Would an Apple watch pick up HR and other sensors etc. if he were to wear a lightweight sleeve underneath the watch in between the watch and his skin?

If others have bruising from blood thinners, is there a band that is suggested? And has anyone discovered a watch that would not cause bruising when worn?

Thank you...