Head-motion detectors: SmartNav 4 and Camera Mouse 2010
Another option for those who can't control a standard mouse and keyboard but do have steady control of head movements is NaturalPoint's SmartNav 4:AT, an infrared scanner that sits on top of a monitor or notebook. The $500 device connects with a Windows PC or Mac and senses head motion in a 45-degree field of view 100 times per second.
SmartNav 4 works by sensing a small reflective dot that can be stuck to the user's forehead, eyeglass frames, hat or headset's microphone; the package includes 26 reusable dots. Move your head around and SmartNav follows the motion to place the screen's pointer where you want it.
Users can type using a virtual keyboard on-screen; actions such as clicking, right-clicking and dragging are controlled with a special toolbar. The software is highly configurable, offering adjustments such as separate X and Y scaling for users with limited horizontal or vertical head motion and smoothing control for those with unsteady head movements.
A free mouse alternative for those on a tight budget is the Camera Mouse 2010 application. Developed by researchers at Boston College and Boston University, Camera Mouse replaces the Windows mouse software with a system that tracks the head's movements with a standard webcam (either built in or externally attached via USB 2.0).
After calibrating the system to a corner of an eye or the space between the nose and the mouth, the user moves his head to move the pointer around the screen; holding the pointer still on a small area of the screen activates a click. It takes some getting used to and isn't as sophisticated or precise as products such as SmartNav, but the price is certainly right. Camera Mouse requires Windows XP, Vista or .