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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?"
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
Upon reading just the title, that actually *was* what passed through my head, followed by trying to come up with what could be a legitimate use for such a switch.
I'd consider this to be either a legitimate question, or a fake one well crafted. It occurs to me that a suicide bomber really wouldn't have the need for GPS anywhere in this system, as the location of someone who has just blown himself up is really rather apparent.
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.
"I have never let my schooling interfere with my education." - Mark Twain
There is already one program that I know of that attempts to do this. It is called DMS, but I can not recommend it, it is very flawed. Among the issues I have with the program: It gives no warning before sending out the death notices that you program, no chance for the user to abort it. It will send out the notices and take other actions (such as deleting files) even if the computer has been down for a long time and then is rebooted (assuming that dms is in the start-up directory where it should be), such as caused by hardware failure or even extended power failure. And it needs manual attention to restart it's count down times, it doesn't recognize from keyboard or mouse activity that you are still alive and restart the countdown, so if you ever forget to reset the counter the messages go out with no warning and no chance to stop them.
While the program is flawed, the concept is not. I keep hoping that I will find another version that addresses these problems and can be used for this purpose. I can see that this would be a big help to anyone concerned about the elderly living alone, anyone with a dependent child (or even a pet) who shares your concerns, and many other people.
I'm an American. I love this country and the freedoms that we used to have.
Actually, DIY surgery is illegal in most cases, even if the other person were to have written something beforehand saying that he/she consents to whatever you're going to do. Ethically, one shall have full rights to one's own body, and if one wants one's friend to implant something, that should be fine, but, the medical profession and Law see it otherwise, and a State may incarcerate an individual for performing surgery on him/herself. You may think that you own your body, but as soon as you try to do certain things, you are deemed criminally insane; from that, I must conclude that I do not have legal possession of myself.
Piercing your own ear, stitching up your own wound, freezing a wart off by yourself, body modification, scarification.... these are all examples of structural alterations to living tissue: self-surgery.
I'm curious as to the statistic of self-injury as emotional behavior among the slashdot population. Would anyone care to volunteer stories or opinions, along any line of thought stemming from said notion?
I make heavy personal use of Asterisk PBX software. It allows my blacklisting unwanted calls. It also allows my own system of "follow-me" call forwarding to pass calls to my cell if the home extensions fail to answer.
Scheduling a call with the cron daemon is pretty easy. A kind of wake up service is also fairly easy to setup. With a cordless phone for home use, this could call said extension at various times of the day. When you answer the call, you would have to press a number or something to confirm that you are fine. Failing to press the number, it could make second attempts in case there was just fumbling, like a followup call within a minute or two. Failing more than once, it could email people, send calls to people, play a recorded message for each call appropriate for the target of the "notification". With the use of a cell phone, it could even check on you when away from home since it could work like any automated phone call/customer service line. Besides having a phone ring to wake you up in the middle of the night, hampering your sleep, I do not know how much help it would be in the night time hours. The cordless phones out now could cover most of people's small yards as well. It can also be easy to "911" yourself carrying it around with you, and with a little more effort, when you call 911, it could make other calls automatcally for you. Think 911 with a custom menu for types of emergencies with phone and email notifications to work with.
The mutltiple notice to people for multiple types of needs using multiple methods of communication could be of some help. Cell phone calls to my house, being identified as my cell phone via "caller id", I get prompted with a menu to allow me to cause things to happen, when any other call would ring the phones in the house. A cell phone speed dial could be setup to call home and cause functions to occur using said "menus" which are limited by what you can get a pc to execute. (email, phone call outbound recordings, serial cable control for some devices, IR controls of something near the computer with a TV universal remote function....)
Some of these ideas could enable automated response testing, and easy one button emergency notification. The GPS portion could be handled by recorded messages from cell phone orginating "emergency button" to mention the cell phone number/carrier to emergency contacts for use in tracking. Not so automated in that respect, but seems to be a workable solution.
As others have noted, this is something crying out for a social solution, not a technological one, but I'll indulge the "build your own" technological fetish for a moment.
Monitoring for falls uses off-the-shelf accelerometers. Another poster in this thread mentioned a BlueTooth enabled heart monitor, of which there appear to be several. The hard bit is notification.
Take a look at the Telit GM682 for the cell phone portion of your control. You can get 'em in quantity one from Spark Fun, and probably other places. It's basically a cell phone with a serial port that takes AT style commands, and is great for mobile hacking applications. After that it's just a microcontroller or a Gumstix depending on where your power consumption, weight, and processing power curves meet.
Given my experiences with cell phone coverage and reliability, I'd have your actual dead-man switch on your server somewhere, and have it trigger if it didn't get an "alive" signal from the device you carry every so often, because it sounds like you'd far rather trigger false positives than have a false negative.