Cell phones, water and wireless mice

I’m embarrassed to say that the link took me a long time to figure out. If you’re wireless mouse or keyboard is having connection problems, signal weaknesses, or similar signs of problems, make sure your cell phone isn’t anywhere around them!

I did this at work for a long time–it screwed up the signal strength, and caused weird problems like dropped keys, stuck CAPS, and more.

I have also noticed signals getting screwed up when I had a Nalgene bottle full of ice water sort-of between the keyboard and wireless receiver.

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4 thoughts on “Cell phones, water and wireless mice

  1. madams

    Similar problems have also been reported when cell phones and wireless phones have been used near wired keyboards, mouses, and near electronic devices such as medical equipment (hearing aides and pacemakers). Some hospitals won’t allow the use of cell phones in operating rooms because of this and other problems.

    The requirement that cell phones not be used aboard aircraft was based on a risk assessment of interference with RF transmissions. The jury seems to be still out on this, although economic considerations, particularly in Europe, are pushing toward greater in-flight use. Another less considered risk that should be examined is how cell phones might affect the wired components of airplanes.

  2. pepethecow Post author

    The thing I noticed was that I only had to move it 6 inches to gain back the functionality. I think it’s important to make sure a distinction is drawn between wired and wireless devices. It’s quite easy to interfere with wireless devices. I think the controversy is about whether wireless devices can interfere with wires–I’ve been a skeptic, but in any case I think I would refuse to fly on an airplane that allowed cell phones to be allowed in flight, purely for comfort reasons. I can’t think of a more efficient form of torture…

    Cell phones and wireless mice and keyboards are such low power devices, I’d really be surprised if they could effect a wire through even minimal shielding.

  3. madams

    I don’t think wireless mice and keyboards would be much of a problem for wired devices, but cell phones operate at up to 3 watts.

    See:
    Why am I not allowed to use my cell phone in airplanes or hospitals? http://electronics.howstuffworks.com/question230.htm

    “If one of the wires in the plane has damaged shielding, there is some possibility of the wire picking up the phone’s signals just like my computer’s speakers do. That could create faulty messages between pieces of equipment within the plane.”

  4. madams

    There are many related articles/studies out there. Here’s one example.

    Turn Off Cell Phones in Hospital Rooms
    Cell Phones May Interfere With Some Critical Care Medical Devices, Experts Say
    By Miranda Hitti
    WebMD Medical NewsReviewed by Louise Chang, MDSept. 5, 2007 — Dutch doctors today reminded hospital visitors to turn off their cell phones — for the sake of health, not etiquette.

    The reason: Cell phones may interfere with critical care equipment such as ventilators and external pacemakers, report the University of Amsterdam’s Erik Jan van Lieshout, MD, and colleagues.

    With that in mind, van Lieshout’s team supports the practice of keeping cell phones at least a meter (about 3.28 feet) away from medical equipment or hospital beds.

    That guideline “seems safe” but doesn’t totally prevent the possibility of cell phones causing electromagnetic interference in hospital equipment, the researchers write.

    They tested cell phones near 61 medical devices that weren’t hooked up to patients.

    In the tests, the cell phones caused 48 “incidents” in 26 devices. A third of those incidents were hazardous, such as totally switching off and restarting a mechanical ventilator, completely stopping syringe pumps without setting off an alarm, and causing incorrect pulses in an external pacemaker.

    Another 42% of the incidents were classified as “significant” but not hazardous. Examples of significant incidents were incorrectly setting off an alarm or inaccurately monitoring blood pressure.

    The remaining incidents were considered “light,” such as disruptions of monitor displays that didn’t require immediate attention.

    The researchers note that their testing situations were “worst-case” scenarios. But they argue that their findings support restricting cell phone use in hospitals to areas where electromagnetic interference wouldn’t be a problem.

    http://www.webmd.com/heart-disease/news/20070905/turn-off-cell-phones-in-hospital-rooms

    The study appears online in the journal Critical Care.
    View Article Sources
    SOURCES: van Lieshout, E. Critical Care, Sept. 5, 2007; online edition. News release, BioMed Central.

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