"Medical" watch with SOS function without phone. About 10-20m range (2-3 concrete walls)

[lastwildland]

Hi and hello, as it's my 1st post here I hope it's good section to post this.

What are my options if I need a watch with sort of SOS function without the need for smartphone? What I have in mind is just a regular-looking watch but if you push a button rapidly than it sends signal to base station which informs of the event.

It must have a range of about 10-20m (passing 2-3 concrete walls). 10m would be enough if I place receiving station in the middle location but it would be pain in the ass as I'd be forced to use batteries for power and have to rely on base-station's functions (which could be extremely limiting). 20m and being able to connect station to USB in Raspberry Pi (RPi 2 I beleve) would be perfect as I was thinking about connecting one to local web for another purpose.

I want this watch to be offline (no need for smartphones etc).
Is there an easy solution or should I sadly post this in Twilight Zone section?

Long battery life sounds good.
If there would be something like HR monitor inside watch itself that I could copy data from using USB (and nothing else!) it would be a nice addition but it's not necessary.

If it happens to be fully open source so I can be sure it's not collecting data for any company and API allowing for advanced usage with RPi it would be truly incredible but I sadly guess in today's world it falls into Twilight Zone category unless I build everything from a scratch myself - not to mention it would take months at best and probably would be very bulky.

Greetings

 

[Nanren888]

I looked at two things about a year ago that might be of interest.
One was an alert system for a lone worker in a basement tunnel area. They preferred out by cellular so that it could have multiple numbers to call if one failed.There were multiple offerings here with low-power wristband + cellular-enabled relay station. Not sure they disclosed what the wrist comms was. Search with words round this theme.
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The other was for alerts when a staff member went missing. They preferred bluetooth. Alibaba, Aliexpress showed multiple conmpanies offering cvarious monitors, from presense, presense + panic, thru to simple vitals monitoring. Again out to a hub that was BLE or ethernet, or probably other options. This application could bare installs of multiple hubs to get round range problems and fill in blank spots.
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BLE might not have the range you want indoors.
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Have not come across an open solution, but multiple of the alibaba vendors offer SDks to let you run extra on the wrist bands and customise services.
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Hope it helps