Breathing monitor....(Beginner)

Hi all,

As a first project I wanted to build an Arduino-controlled baby-breathing monitor, similar to this:

http://www.angelcarebaby.com/item/usa-v ... 1Tbu5F97b0

I'm not working on the video or sound capabilities, just the breathing detection using the pads.

The way it works is that the pads are positioned underneath the mattress in the cot. When the baby breathes, it records it as OK. If there is no movement the thing starts beeping loudly.

I am trying to work out the best way to build the actual sensors. I was thinking of building a "pad" using
a set of four (or more) load sensors to detect changes in weight resulting from movements.

Has anyone had experience with load sensors and is this feasible? Especially given the presence of a cot mattress over the top. The goal is to detect a slight change in weight from faint movements, not necessarily to get an accurate weight measurement.

Thanks in advance for any words of wisdom :slight_smile:

cheers

The link doesn't work, of course.

This sounds like a difficult project for an expert, let alone a beginner. Load sensors need significant external amplification (requiring skills with electronics and noise reduction techniques) to be useful with Arduino, and it isn't clear whether they would even work under a mattress.

Force sensitive resistors are easier to use and might work, but even if so, a lot of experimentation will be required to pull out a signal that could reliably detect breathing.

Accelerometers would detect crib movements, but probably not breathing.

How are your signal processing skills?

What if the accelerometer was part of the baby’s clothing? Might be easier to detect movement that way.

Sounds like something you would only be allowed to use once! :slight_smile:

I have looked into detecting/monitoring breathing of sleeping people using microphone, the required signal processing is probably beyond the Arduino platforms unless you use Teensy or similar. What I think would be great is to create an app for a smart phone that would monitor the breathing and call a number with a verbal message after the phone was answered. There could also be an audible alarm using the smart phone in addition to or in lieu of a phone call to alert the caretaker.

I realize I am taking this posting off track but thought this might add to the discussion.

Just a thought. Suppose you have a chest strap that fits around the urchin, but is designed to be fairly loose and comfortable. The left side and the right side of the strap contain two separate conductive surfaces which make contact with the baby's skin. When the chest expands a little, the intra-baby resistance drops. Make this part of a voltage divider, and monitor it with an analog pin.

Aside from the amplification issue, a pressure sensor in the mattress pad would have a higher resolution. You might think about a cheap motion sensor in the mattress pad or one in each corner. These have pretty high sensetiviy.

travis_farmer:
It may also work to simply develop obsessive compulsive disorder, and personally check on the baby [...]

It's called "parenting". :}

What is this concern about a baby stopping breathing? I believe breathing problems have been discounted as a cause of SIDS.

They are more likely to get into trouble as a result of getting tangled up in hobby electronics and asphyxiating.

aarg:
What is this concern about a baby stopping breathing? I believe breathing problems have been discounted as a cause of SIDS.

What??? As far as I know people (without artifical ventilation, ECMO etc.) are breathing if and only if they are alive.

Load sensors detect a change in weight, not so much a difference in body/chest movement.

To see a simple one in action watch my YouTube video #31 & #32, it's quite simple but not one I would want to build as a breathing monitor - well, I might build it but then check that it actually detects breathing (it is very sensitive, down to a 1g difference so who knows, it might even work).

If you're interested in following this path the URL for my videos is in the footer of this post.

Smajdalf:
What??? As far as I know people (without artifical ventilation, ECMO etc.) are breathing if and only if they are alive.

Well, that's the other way around. Obviously, if you die you will stop breathing. That doesn't mean that if you get hit by a car and die, it means you died from lack of oxygen.

aarg:
Well, that's the other way around. Obviously, if you die you will stop breathing. That doesn't mean that if you get hit by a car and die, it means you died from lack of oxygen.

And?

You know any other usable contacless device to monitor if a person is alive? Why you care so much about the cause?

Technically speaking nearly everyone dies from lack of oxygen: a car hits you, you loose blood, without blood the organs (brain) cannot get oxygen, you die.

I strongly recommend not wiring up a baby, and if the baby at normal health, the fear of them not breathing will go away in time, and with the second one I think most ppl do not think about it at all.

But in theory, !(would) the best approach be to monitor the pulse?

Contact microphone to detect breathing, through the mattress.