interesting project. Using Kinect to detect hand positions is going to be complicated (for me at at least). Kinect works best when detecting body gestures, near mode enables the body to become closer to the Kinect, but does not enable the tracking of individual fingers.
A possible solution would be for you to investigate Detect Object, Detect Object cane be trained to recognise hands in certain positions.
Other hardware options soon to be released include Leap Motion (designed for hand tracking, reviews are not good at the moment, let’s see what happens on release) and Intel’s Perceptual Computing (to be released soon).
Obvious Engine looks really cool - I’ve never tested though, might be worth contacting the the company behind it:
Please let us know how your research goes.