BioEd Online

Although it may never reach the market, a new type of dating tool could give inspiration to the romantically challenged. By attaching electrodes to regular eating utensils, inventor James Larsson has created knives and forks that can pick up on whether the person across the table feels uncomfortable or pleased.

London-based Larsson hopes to help those who have difficulty reading signals such as body language from their date. "Geeks have major challenges dating," he says. The device analyses data from the cutlery to provide information about how their dinner companion is feeling.

The system relies on electrodes to measure the skin's resistance to electric charge, like those used in lie detectors. When people feel suddenly stressed, their skin's resistance plummets, partly because any sweat released under these circumstances facilitates the movement of charge.

Lie detectors have relied on this phenomenon for decades, but only now have the sensors been brought to the dinner table, says Larsson, who described his invention on 16 March at the O'Reilly Emerging Technologies Conference in San Diego.

Under pressure

When he started building the as-yet-nameless dating device in 2001, Larrson originally aimed to make the system covert. In the ideal setup, dates would not know that they held a special monitoring device in their hands while eating. "This would allow you to privately remedy your own lack of perception," he explains.

But lots of wires are currently needed to connect the knife and fork to a computer monitor, so the technology has not yet achieved this secrecy. And because dates must hold both utensils to allow the small, stress-measuring current to run through their body, the device does not work with when someone eats holding only a fork.

Making the electrodes work on cutlery was a challenge. Lie detectors are generally used in a controlled environment where the subject sits still. But when people eat, they constantly shift their fingers over the different electrodes on the special utensils. And they apply varying pressure as they cut pieces of food on their plate.

To address the first problem, Larsson designed specialized software on the machine to which the fork and knife relay information. The program selects data from only those electrodes touching the hand at a given time and ignores the ones without contact.

He has also attached strain gauges to the utensils. These run to the computer as well, preventing the system from mistaking increased pressure as heightened stress.

Date data

The result is a computer that produces graphs to show when the person eating felt uncomfortable and when they were more relaxed. Because the system remains obvious, with all of its wires, it has yet to be used on a real date. But Larsson has tested the device on himself during a lunch with his mother. The graphs revealed that he felt stressed.

The inventor readily concedes that the system may not help any couples get together in the near future. At the moment, its value is more playful. "Hopefully there's a good dollop of humour mixed in because that's what I intended," he says.