Whenever i want to take a nap, i have to set a kitchen timer for 30 minutes or an hour or whatever. The problem is, I then spend a variable amount of time actually getting to sleep. So, if i set an alarm for 30 minutes and then spend 20 minutes of time going to sleep, i get only 10 minutes of sleep. On the other hand, if i try to "figure in" something like 15 minutes of "falling asleep time," i seem to go to sleep instantly.

what i'd like is an alarm that you set to go off a certain duration of time after you fall asleep. Maybe there's some way it could monitor your body's signals (breath rate, or brainwaves, or something) and determine when you fall asleep--then wake you up 30 minutes later.
-- Urania, Aug 14 2001

Anti Sleep Alarm http://www.amazing1.com/security3.htm
Scroll down [FloridaManatee, Oct 04 2004]

Eye Blink Rate http://www.remware.com/teknta06.htm
for the detection on sleep onset [FloridaManatee, Oct 04 2004]

Pulse Oximetry http://www.nda.ox.a...tml/u05/u05_003.htm
Passing out from lack of O2 [FloridaManatee, Oct 04 2004]

Brain Electrical Activity http://www.epub.org...neurobiologia_i.htm
[FloridaManatee, Oct 04 2004]

Stages of Sleep http://www.dreamvie...om/sleepstages.html
[FloridaManatee, Oct 04 2004]

It wouldn't work for me, but I voted for it anyway. When I have to get up to an alarm of any sort, I only barely get to sleep. My mind keeps going 'Was that the alarm? We should look. What time is it? Was that the alarm?'
-- StarChaser, Oct 27 2001


When I saw the title was thinking of an alarm clock that stops you going back to sleep... but both features could probably be on one device ...
-- RobertKidney, Oct 27 2001


I think that is at least partially baked. I seem to have heard of a device to prevent people from falling asleep while driving. I don't have a link though.
-- PauloSargaco, Apr 30 2003


Like many pilots, when I fly solo cross country over mountains, I need to know right away if I'm 'zoning out'.

There's many devices that could work for your application, from tilt sensors to brain wave measuring devices. I've added a bunch of links that provide details.

One practical suggestion is to ask someone to start the clock from when you start snoring!
-- FloridaManatee, Apr 30 2003


Apparently burglars going into occupied premises know if a person is asleep by their regular breathing. ....The noise of someone unknown moving around your house kind of concentrates the mind, and you hold the breath while your ears do all the work.........

If you want a trigger to start the timer, then the presence of regular breathing could be used..... but if you've woken up too early, don't hold your breath or the alarm goes off.
-- peter2, Apr 30 2003



random, halfbakery