How Can I Build a Portable "Dead-Man's" Switch?

An anonymous reader asks: "I'm a widower caring for my very disabled child. I have family who check in on me often, but not reliably, and not every day. How can I rig up a 'dead-man's switch' that will alert family or emergency services should something happen to me, so that my child can be cared for? Her medical needs are significant enough that being alone for even an hour could be fatal for her. We do occasionally get out of the house, so a GPS type cellphone and a heart-rate monitor watch would seem to be the ticket, but how to link the two and get the desired dialing behaviour?"

Comments

Re:Homeland Security

[pete-classic]

Are you advocating peace through censorship? Do you honestly believe that is workable?

Our species survives because most of us are decent. The day that ceases to be true this little experiment called "Man" is over. No "Loose lips sink ships" jibber-jabber is going to prevent that.

-Peter

Some ideas

[RobinH]

I don't think you need a dead man switch. (I work with dead man's switches all the time in industrial robotics). What you could probably get away with is a vigilance control switch. From Wikipedia:

Vigilance control, also called an alerter, is similar to a dead man's switch, the difference being that a vigilance control system requires that the operator press a button at specified regular intervals. If the operator fails to operate the vigilance control, a warning sounds, and should the driver still not operate the vigilance control the machinery will stop.

I have one of these motorola pagers that my company gave me to carry around. It may only be available in Canada, but I'm sure you can find something similar in your area.

At any rate, you can send a page to it with an email, and then you have the option to reply to the email with a canned response like "OK" or "Will call back soon", etc. I was thinking that you could write a script on a server that would kick off an email to your pager every 30 minutes and if it didn't see a response within 15 minutes, activate some kind of emergency routine like contacting a relative. The timing could be varied to your needs.

It would be easier if you had something that hung around your neck, or a wristwatch that beeped every 15 minutes and required you to push a button to silence the alarm. Not silencing the alarm would somehow trigger your emergency routine. Using a windows mobile device or a blackberry (the API is available for free) you could write a program for one of these devices to do this task and send an email if you failed to respond.

Of course, this only works during waking hours. I don't know if you hire someone to watch your child during the night while you're asleep or not.

I ran across this article. I wonder if it has gone any further than that.

Good luck with the search.