Computer Feedback in Meditation Are there any meditation computer  feedback programs out there? Like Biofeedback.

What could they do? Allow a teacher much insight into a student? Allow a meditator to know when wandering is happening,  when subtle thinking is happening or to know when reality is seen directly or with concepts? 

Would this be a helpful tool to be used all the time, only  sometimes or never?-(Perhaps because it creates a duality, it creates aversion, it's unnessasary, it's not in the Pali Canon or anything).
Biofeedback programs just take data such as heart rate, blood pressure, etc... and display them on a screen so that the person can see them. The underlying theory is that if a person can directly see what's going on, they would be better able to adjust themselves to slow them down.

Because these devices cannot directly access the mental activity of the meditator, I don't see how they could be of much use. Certainly if one is developing some form of calm abiding it might be useful to an absolute beginner, but once they start making progress, even stopping to check the machine readout would be comparatively distracting and would erode one's concentration.