just an idea.
I know there is some tools out where you can install, it is kind as a calendar but the funny thing is that it shedule for those who works all day in front of their computer an alert when to take a break.

May be this can be included in Google Calendar ... fixing a break and it can show you how many minutes or hours you used the mouse, the keyboards....

The PDF not supporting Chinese characters yet...

I think that there are some s/w installs which can monitor the user k/b usage and mouse. It actually tracks the mouse hot spot to figure out which zones on a specific screen are 'hot'. This is part of UX'er strategies for desingers and developers!!