Slashdot Mirror

← Back to Stories (view on slashdot.org)

Sonar Software Detects Laptop User Presence

Posted by timothy on from the what-are-you-doing-dave dept.

Steve Tarzia writes "A research group at Northwestern University and University of Michigan has released open-source display power-management software that uses a new user presence detection technique. The goal is to shut off the display immediately when the user leaves the computer rather than using slow and error-prone mouse/keyboard activity timeouts. Surprisingly, the mic and speakers of many laptop computers are sensitive to ultrasonic frequencies. Those frequencies can be used to silently probe the laptop's physical environment. This software is based on research published at the UbiComp2009 conference. A Windows binary and source code for Windows and Linux are available for download."

7 of 167 comments (clear)

  1. Takes Care of one of my pet peeves by gpronger · · Score: 3, Interesting

    Don't know if I type slow, think slow, or both, but one of my pet annoyances is when the screen saver kicks-in as I'm staring at the screen in thought (sure I know how to set it, but I am not always in front of my own PC, and oft away and then back a lot through the day).

    If this will simply tell the OS, hold on, he's sitting there doing something, I'd find it a pretty neat idea.

    Greg

    1. Re:Takes Care of one of my pet peeves by schon · · Score: 4, Interesting

      Something like this has been available for KDE for ages, only it uses Bluetooth.

      You tell it to listen for your phone - when you leave your desk (presumably with the phone in your pocket/holster/etc.) the screen lock kicks in.

  2. I wonder how... by Whorhay · · Score: 3, Interesting

    I wonder how fine of a resolution is possible with a setup like this with generic microphones and speakers. Maybe it would be possible to use this as a biometric lock on a computer system. It could function as a facial recognition check using the ultrasound picture or series of pictures of your face. Lighting wouldn't affect it and someone couldn't simply use a picture of you to try and fool the camera. Even a bust of your face wouldn't work the same unless it accurately simulated your bone structure and flesh.

    1. Re:I wonder how... by maxfresh · · Score: 3, Interesting

      I agree that a webcam would do a far better job than speakers and mic, but they couldn't use body heat to do it.

      Although a ccd or cmos sensor in a webcam, or most any other digicam, is sensitive to IR as you mention, it is not sensitive to the thermal IR of body heat. Most digital cams are capable of IR sensitivity out to about 1um, if you remove their IR-cut filter. The human body with a skin surface temp of about 305 Kelvin emits most of its IR energy at a wavelength about 10x longer than this, or 9.5um.

  3. I'm one of those people that hears CRT Monitors by ArbitraryDescriptor · · Score: 4, Interesting

    And dimmer switches, cordless drill battery charges, and even a really annoying slice of whatever frequency god damn bats chatter at. In short, my super power is above average HF hearing. Hooray for me...

    Now, I like this idea, it's neat, I just really hope it operates well over 18khz so my head does not explode all Scanners style when I walk into a room full of laptops.

  4. Re:Activity by Red+Flayer · · Score: 5, Interesting

    Your privacy concerns are valid... however think of the applications for this tech.

    /+5 Hat of Greed equipped.

    Oooh, I'm drooling! Let's see:

    $APP detects two people within viewing distance of your monitor. [click here] to upgrade to the appropriate license.

    /+5 Hat of Greed unequipped.
    /+5 Hat of Stealth equipped.

    Oooh, I'm drooling for different reasons. Let's see:

    $APP detects additional person approaching monitor. Autominimize firefox://ridiculous.pornsite.com; automaximize firefox://romanticweekendgetawayswiththewife.toshowherhowmuchyouloveher.com.

    Whew, that was a close one.

    --
    "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
  5. Re:How about a license ; how about saying Linux(tm by olau · · Score: 3, Interesting

    You got that backwards. What they should do is deleting the remark about Windows. Anyone succumbing to the (tm) crap should have their head examined. Every time somebody writes "registered trademark", god kills a kitten. It's true. Between us, we just killed two. No, I'm not going to write it again.

    Now someone is going to say legal blahblah necessary blahblah. But there is something wrong if fear of a big corporation is making you write that kind of kitten-lethal nonsense every time you mention a product made by that corporation.