Lucent brainiacs have filed a patent application for a DVR sleep detector. They envision a DVR-integrated “apparatus” which pauses TV playback once an individual has fallen asleep. Upon regaining consciousness, DVR playback resumes. The application covers both video surveillance and physiological monitoring to determine wakefulness. No word on how they’ll handle those risqué folks who watch TV together.
Lucent says:
[0011] The sleep detector may comprise an electronic camera for forming images of the viewer, and pattern recognition means connected to the electronic camera to monitor the physical condition of the viewer. For example, the pattern recognition means determine whether the viewer’s eyes are open or shut. The apparatus may further include logic means connected to receive output from the pattern recognition means to distinguish normal blinking from the onset of sleep.[0012] Alternatively, the sleep detector may comprise a device wearable by the viewer for monitoring the physical condition of the viewer. For example, the wearable device may include one or more of an accelerometer, a heat flux sensor, a galvanic skin response sensor, a skin temperature sensor and a near-body ambient temperature sensor.
[0013] The sleep detector may be connected to the digital video recorder via direct electrical connection or via a remote-control type interface.
Logitech has begun shipping the new 
to select Walmarts, which resulted in numerous phone calls and a distant quest to two stores. Why Walmart you ask? Logitech is aiming squarely down market with this $99 model – and I’ve concluded the cost corresponds directly to the number of buttons.