Page last updated at 10:00 GMT, Friday, 4 September 2009 11:00 UK

Smart sensors power interaction

By Jason Palmer
Science and technology reporter, BBC News

Robot Elvis (CambridgeU)
A robot Elvis that mimics visitors' movements was also on show

Future directions of how people will interact with technology were on show at the Human Computer Interaction conference in Cambridge this week.

Much of the conference was dedicated to the finer details of human-computer interaction, such as how web pages are organised for optimal information presentation or the practicalities of cataloguing the web's information using the "tags" familiar from social networking sites.

But at the conference's Open House Festival, there were more than 70 demonstrations ranging from interactive-tabletop learning technologies to holographic projections and wireless-enabled scent-squirting jewellery.

Sensory substitution demo (OpenU)

One novel experience to be had was that of "tummy vision" - an array of the vibrating motors found in mobile phones strapped to the stomach as part of a game.

Forty years ago, Paul Bach-y-Rita began a field of research known as sensory substitution. His idea was that if a person was deprived of a sense such as sight or hearing, it could be "mapped" onto another.

His first incarnation of the idea was a dentist's chair lined with hundreds of solenoids - small pins that jut out when a voltage is applied - each connected to a pixel of a camera. A blind person could sit in the chair and images from the camera were transformed into patterns of the solenoids that the sitters could feel.

After tens of hours of training, people could be made to recognise images. In 2001, Professor Bach-y-Rita had developed a similar approach with electrodes arrayed across the tongue.

Fun and function

These days, researchers from the Open University's e-Sense project have pared the idea back its most basic form, developing the "tummy vision" corset from cheap, off-the-shelf parts and programmed with open source software.

A camera tracks the progress of a participant's gloved hand as well as that of ball rolled across the table. The table is divided into 16 sections, each corresponding to one of the tiny mobile phone motors.

As the ball travels toward the blindfolded player, the vibrations track across the player's abdomen, the object being to guess where to grab the ball before it rolls off the table.

Those trying it said it was fun - partly because the vibrations tickle - but crucially, the game can be mastered in just a few trials. The kit is cheap, completely portable, and is already seeing applications elsewhere.

Already the researchers have adapted the system to guide violin students on the correct trajectory and speed of their bowing.

HTC Magic handset (AP)
The functionality is not the only slick thing about touch-screens

Another use of the vibrating motors is in mobiles themselves. Many touchscreen handsets currently offer tactile feedback in the form of a simple mechanical buzz as virtual buttons are pushed.

But Stephen Brewster of the University of Glasgow has plans for the linear motors found in modern handsets. They can be programmed to start off vibrating quickly or slowly, and at a wide range of frequencies.

Changing the nature of the vibration gives distinct feelings in a user's fingertips, and Professor Brewster has replicated some familiar sensations through careful choice of vibration patterns and modulations.

On display was a simple touch screen with a few buttons. The program within makes a "soft click" feel more like a computer keyboard, and a "hard click" has the satisfying response more akin to an old mobile phone keypad.

Eyes-free operation

The trick now, Professor Brewster said, was to replicate the overall feel of such a keypad.

"With old phones, you could reach in your pocket and feel the buttons; if the phone rang you could answer it as you raised it to your ear," he said. "With my iPhone I've got to look at it and do all sorts of things before I can answer a call."

Professor Brewster's team is fine-tuning the vibrations across the face of a touchscreen phone so that the feel mimics a proper keypad with its rounded keys raised in the middle, and with distinct shapes at different positions.

For example, sliding a finger along the screen from one virtual button to another prompts a short, light buzz that mimics the roughness of a real keyboard.

Getting the right combination for a touchscreen phone that really feels like a proper keypad is still a work in progress, said Prof Brewster.

Sensebulb text messages (Girton Labs)

Also on show was the SenseBulb, a light bulb with a standard fitting but with low-power, high-brightness LEDs inside, along with a great deal more technology.

Developed by Lyndsay Williams of Cambridge's heads up Girton Labs, the device uses four sensors known as thermopiles - the same kind of detector found in heat-seeking missiles. They sense temperature differences accurately and over a short time from a narrow angle.

Put one in the kitchen, for instance, and it won't register a pot boiling on the stove. However, it would note that the oven was over its usual temperature, or that the fridge or the back door had remained open for a time.

With a SIM card built in, it can be set up to send text messages automatically to a specified recipient whenever temperatures in a given part of the home fall out of a set range.

The thermopile sensors could even, Ms Williams said, register the waving of arms - and for this reason she said it could be an unobtrusive and passive movement sensor for Alzheimer's patients or elderly people who live alone.

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