

If you have an iPhone, you can get an Apple Watch and set it up using the other person’s phone. The health app will tell you what the person’s heart rate is. It will also do sleep tracking and check blood oxygen levels. It will also notify you if the person falls. It can also be used to contact 911 if it is in range of your phone, or if you buy the cellular version and add it to your cell phone plan.
If you live near an Apple store, stop in and ask about it. The trick will be to set up/link your spouses watch with your iPhone so you can continuously monitor the other person.
Found this article. It looks like this is the easier way to set up an Apple watch for somebody else in your family that you can monitor. There’s probably something similar for android watches.
https://support.apple.com/en-us/109036