Toronto, Aug 29 - People with speech disability will now be able to speak, literally.

A Canadian professor at the University of Toronto says heat-seeking infrared camera can pick up mouth gestures of a person with speech disability and then pick the letters of the alphabet to translate the gestures into verbal message.

According to Prof Tom Chau, who is senior scientist at Bloorview Research Institute of the university, infrared thermography can help people with speech disabilities to interact and perhaps eventually communicate.

Infrared thermography, he says, refers to the measurement of radiation or heat emitted by the surface of an object, including the mouth.

Infrared cameras with specialized lenses can pick up this radiation or heat and focus it on a plane of infrared detectors.

Explaining his breakthrough, Chau said his research involves exploiting the temperature changes associated with the opening and closing of the mouth.

'The human body is an emitter of radiation (or heat) and the radiation that is emitted can be measured,'' he was quoted as saying in a university statement.

He said, 'In the (human) face there is a complex network of blood vessels. When you experience different emotions there is different flow of blood through the face and this causes temperature changes we measure non-invasively using a thermal camera.''

Chau, who came up with this idea while working with a patient with speech disability, said, 'One thing (this patient) could do reliably was open and close his mouth and that is a very tricky thing to capture.