It’s a Haptic device which simulates a pen in 3D free space with the help of a software called VTK Designer.
Phantom Omni is developed by SensAble Technologies which is a company evolved from undergraduate research done at MIT in the 1990s by industry pioneers Thomas Massie and Dr. Kenneth Salisbury and is headquartered in Woburn, MA. It can be well used to guide the hands of the blind to make them learn not only alphabet but any piece of drawing. When tested on 8 blind students, within 20 minutes of practice they could easily write.
In the real world the user holds in his/her hand a pen attached to a mechanical arm placed on the top of the desk. The arm design enables the user to maneuver without being disturbed by the equipment weight. The physical pen being held by the user is translated into its virtual counterpart rendered on the screen. The virtual pen follows the movements of the physical one and when the virtual pen collides with virtual objects appropriate forces are sent to the physical pen and its guides the user accordingly. It can also alarm the user by sending audio signals on how and where to steer the pen.