Microsoft Sees Human Body as an Antenna
A laptop and a USB data acquisition device are worn in a backpack. A wire connects the data acquisition device to a conductive pad strapped to the participant’s neck.
CREDIT: Microsoft Research
A team of researchers from Microsoft has discovered a home automation system that could eliminate costly rewiring and outsmart even the smartest appliances.
The Redmond, Wash., team has shown that the human body is a natural antenna. It reliably picks up the electromagnetic signals that emanate from all electrical systems and appliances in the home. These ambient signals can be used to create an affordable home automation system that controls household electronics with a pat on the wall or even a simple hand gesture.
The researchers conducted a set of experiments in 10 houses representing a variety of construction types in the Pacific Northwest. Each homeowner was equipped with a laptop and data-acquisition device and had a sensor pad strapped to his or her neck.
Although the test equipment for their initial experiments was rather bulky, the researchers concluded that the sensing equipment could be incorporated easily into a watch or mobile phone.
The home control system would require training, including input from the homeowner to essentially "teach" the wearable software the layout of the house, calibrate electrical components, and program simple control gestures. Family members could devise their own personal gestures for home control, the researchers noted.
Walls as sensors
Since it is hard to see the actual electrical wiring behind walls, researchers proposed a "stud finder" approach, in which the homeowner runs his or her hand on the surface and audible feedback indicates whether the area under the hand contains enough signal for interaction.
By examining the noise picked up by the body, the absolute touch position around a light switch or blank wall near electrical wiring within the home was determined with nearly 87 percent accuracy. The system could even discriminate between left-, right- and two-handed contact more than 96 percent of the time.
The ability to turn almost any wall surface or electrical device in the home into an interactive input system would make the possibilities for controller-free living virtually limitless. Gestures could be mapped to digital lighting in a room without the need for switches; tapping above or below any existing light switch could raise or lower the thermostat from any room, or control the volume of music playing from a housewide audio system.
To test the new system with common appliances, the researchers focused on two of the original 10 houses. Homeowners touched each of six appliances in the two kitchens: refrigerator, freezer, stove, microwave, dishwasher, and faucet. They were reliably classified by their ambient electrical signatures 100 percent of the time.
This suggests that "uninstrumented" appliances could be turned into real-world "buttons," eliminating the need for complicated knobs and panels.
Researchers concluded that the ability to scale the entire home into an input system also opens the door to a breadth of new gaming and general computing applications that could easily be deployed in any home. Exploring and building these applications remains future work.