I am on a bit of a fishing expedition so please bear with me. Surgery has left me having to sleep in a sitting position at about a 45 degree slope. A contoured foam wedge keeps me in position most of the time but I can either slip down or lie on my side. Either way reflux ends up in my lungs. This can lead to pneumonia. I would like to build a wearable sensor or set of sensors which could detect my change in position and give me a buzz if the position l lasts for more than a few minutes. I’m handy with electrical work but will need coaching on the electronic side. I see this as the last chance to avoid being strapped into place for the night. Thanks so much for any thoughts you might have.

 

There are several Axis sensors available but they need to be used with a micro like an Arduino or Pic,, you could use your mobile phone using the incline sensor built in, and probably an app to go with it,,or making a tilt sensor using a ballbearing in a tube with a couple of wires to a buzzer, like on pinball machines,,

https://uk-m.banggood.com/LM393-Min...MI752W7MrR5gIVxrTtCh35GQ_rEAQYBCABEgJTYvD_BwE

 

Have you considered a fall monitor as the quickest solution? Some can be programmed, I believe, for your starting tilt. Then give an alarm when that approaches horizontal.

 

A trick used for sleep apnea, to stop folk rolling onto their back, is to sew a pocket onto the back of one's PJ top and insert a tennis ball in the pocket. Something similar on the sides may work.
But there are many Arduino or ESP8266 accelerometer projects around that could be modified to sound an alarm too.

 

I am on a bit of a fishing expedition so please bear with me. Surgery has left me having to sleep in a sitting position at about a 45 degree slope. A contoured foam wedge keeps me in position most of the time but I can either slip down or lie on my side. Either way reflux ends up in my lungs. This can lead to pneumonia. I would like to build a wearable sensor or set of sensors which could detect my change in position and give me a buzz if the position l lasts for more than a few minutes. I’m handy with electrical work but will need coaching on the electronic side. I see this as the last chance to avoid being strapped into place for the night. Thanks so much for any thoughts you might have.

There are a few ways;
1:sensor mechanical alarm via electronics
2: completely electronics possible but requires skill about motion sensors.

1: use a pipe with a small marble and two contacts at the end.
make sure that the marble starts rolling before the 45 degrees is reached.
electronics contact start counter when activated (contact open) it will count to minutes required and then activate ( intermitted) alarm.
reset alarm manual.
disadvantage: sensor should correctly mounted to body.
needs hardware counter.

Other method use a pot-meter with arm and weight. (multiple directions possible)
When rotated the resistance will change as function of angle.
electronics start counter when angle is reached then count to minutes required and activate ( intermitted) alarm.
reset alarm manual.
Advantage: Set zero degree after body fix is possible. Small and easy to build. 10 x 10 x 25 mm sensor only.
Size electronics depends on components used.
needs small mpu like pic12fxxx
And a power low alarm. use the logic( alarm is always on unless detector indicates differently embed broken wires detection in your design. )

Movement damping mandatory in in both cases.

Picbuster