Body Rocking Sensor

Hi All,

I want to build a device that will sense when a person who is blind starts the involuntary body rocking action. A blind person can sometimes begin this action unknowingly when sitting down and it can be quite embarrassing. My idea so far is Arduino based(obviously) with a wireless accelerometer which will track the movement and once passing a certain threshold send a signal to maybe a vibrating bracelet which alerts the blind person they are carrying out the action. The Arduino is the middle man as such which will translate the data received form the acclerometer and then pass it on to the output bracelet or warning device. Thoughts?

What would be the best accelerometer for this? Not necessary for 3-axis type I don't think.

And just how would i go about it. The device will be wearable so non-intrusive by all means.

Any help would be appreciated.

Regards

Ferg

Is there any help out there guys at all? even as regards the accelerometer?

Ferg

Not sure where you were thinking of having the accelerometer / sensor but a necklace would seem the most obvious place to me. In that case it would be simplest to put the sounder/vibrator/whatever in the same device - that avoids the complexity of wired or wireless communication. If you're using a lillypad there is an accelerometer that uses a similar design - otherwise I assume you'd be using one of the tiny Arduino clones and any cheap accelerometer that's Arduino compatible would be adequate - there are several 3-axis accelerometers available for essentially the cost of postage.