Darrell Huff, a 51-year-old automotive technician from Centreville, Md., wanted his quadriplegic son, Joshua, to be able to make calls on a cell phone. Unfortunately, all cell phones require button pushes, so Huff quickly thought of Bluetooth headsets as a solution.
He was especially intrigued by the BlueAnt V1, which has a unique voice-control interface that lets you make and answer calls with voice alone--there's even a voice-guided tutorial if you need some guidance. (The V1 is the predecessor to BlueAnt's more recent BlueAnt Q1).
But even the BlueAnt V1 wasn't 100 percent hands-free; you still needed to press the button to activate it. So Huff set out to find a way to activate the switch without the need for hands.
"I tried different things," Huff said. "It occurred to me a mercury switch might work, but my research soon showed that mercury is all but banned in the U.S. and I also began to worry about the user's perception... I tried using a roller ball-type tilt switch, but it is difficult to find one small enough and my experiments showed the connection with this type of switch was erratic."
After a lot of trial and error, Huff finally decided to use a magnetic switch.
"I opened the headset and replaced the push button switch with a magnetically controlled switch," Huff explained. "The modified version of the headset has a switch that is closed when in the presence of a magnetic field. So when the headset is not near a magnet, the switch is open...If you move the headset near a magnet, then the switch closes--this is like pushing the button."
In case you need to push and hold the button, you would just keep the headset near the magnet for a few more seconds. Huff is careful to note that the switch itself is not magnetized; it just responds to a magnetic field.
Now all Huff had to do was mount a magnet so his son could move his head conveniently to activate the headset. He created one that is on the end of a 29-inch long and flexible rod that can be mounted to a wheelchair. At last, Huff had created a genuinely "hands-free" Bluetooth headset. … Read more