British researchers have developed a robotic pen that they say may enable blind people to write clearly and consistently.

All that one will have to do to use McSig – as the “force-feedback” pen has been named – is to gently guide one’s hand.

Stephen Brewster, an expert at the University of Glasgow, says the system uses an off-the-shelf haptic device by US-based SensAble Technologies, called the Phantom Omni – a stylus mounted at the end of a motorised arm, which is capable of moving and resisting movement in three dimensions.

Under the guidance of a teacher, Brewster and his colleagues tested the system on eight visually impaired children: three of whom were partially sighted, and five were completely blind.

The teacher first wrote a letter on a touch-sensitive computer screen using a normal pen.

The Phantom re-enacted the motion required to write the letter as the pupil held the stylus and, thus, gave them a sense of how to move a pen to produce a letter.

Besides haptic feedback, the system also provides audio cues using stereo sound to guide students as to how they should move the pen.

The system pans the sound from left to right as the pen moves horizontally, and increases and decreases the pitch to signify forward and backward movements.

After a practice of about 20 minutes on the haptic device, the students tried writing with a regular pen on a plastic film known as Dutch drawing paper, which creates an imprint that can be felt after writing.

The students – all of whom were unable to write before the training – started to write recognisable letters after the practice session.

The researchers now plan to conduct longer-term trials with the new device.

“Even though we don’t write cheques any more, it is surprising how often you are asked to sign and date a form,” says Sile O’Modhrain, a visually impaired haptics expert at Queen’s University Belfast in Ireland, who was not involved in the study.

“Besides, there is something demeaning about having to ask someone to sign something on your behalf and thereby become a proxy for you,” she adds.

Talking about the significance of the new device, Brewster says: “The nice thing about our tool is the teacher can create stencils so the kids can practice any time.”

While the Phantom device is costly, the researchers believe that similar software may lead to cheaper models costing about 100 (Rs 4,000 approx).

The results of the study were presented at the 26th Computer and Human Interaction conference in Florence, Italy.