Well unfortunately the original poster is no longer on this site. So her original enquiries/probing don't really mean much.
At the moment this device is on hold until such time as I can find someone to redesign it.

As for some technical questions:
It will use electrodermal response to determine REM. This is similar to a lie detector, in that it finely monitors the conductivity of your skin.
It has been tested, and it worked so well that we could even see a lucid dream on the chart.

When complete, it would most likely consist of a glove with some electronics on it. Or alternatively it may have wires running from the glove.
I'd prefer to avoid the wires and have the device self-contained.
It should be able to log the information as well as trigger your awareness with either a mild vibration device or a connected mask with lights.
I don't like the mask idea, personally, and would prefer the vibration on my wrist.
Less wires again, too.

Oh and the device is called the 'DreamCatcher glove'.
I'll let everyone know when I have the go-ahead to continue developing it. But I wouldn't advise holding your breath over it. My life is in an ongoing hiatus.