I have been thinking about the Pip Boy device from the Fallout series of videogames. It is a portable, wearable computer that can gather a lot of data about the user. It looks like this:
And gives out readings such as this:
Its "home" screen shows the user's medical condition.
The Pip Boy's capabilities are meaningful for the context of the videogames where it exists, but are too handwaved for real life.
What I would like to know is which capabilities a realistic one could have. I know some wearable devices can measure heartbeat, blood oxygenation, sugar levels etc. I want to know how many more parameter readings we can pack in a portable, wrist-worn device.
Technology level: current or near future - in thid case, what could be reasonably expected to be achieved in the next ten years.
The device should be no longer than 33 centimeters/1 foot, approximately. It is ok for it to be as small as a wristwatch if the technology allows for it, but it should still be able to read out as many parameters as possible.
The device needs to either have a screen with readouts of its own, or be capable of sending data to a smartphone or other smart device.
The device may be able to interface with other sensors, but must be able to work in complete standalone mode (except for the screen, as per the paragraph above this one).
Piercing the skin to collect blood is allowed.
Costs are not a constraint.
I read a book about a guy who built a rowboat and rowed from Africa to South America on his own in a couple months. I think that if adventurers like him are able to have their readouts while doing their adventuring, they can remotely contact a doctor for advice. I am going to use this in a story I am writing.