Robot playmates may soon be able to help autistic kids learn the social skills that they naturally lack, courtesy the development of a system that allows a robot to monitor a child's emotional state.

"There is a lot of research going on around the world today trying to use robots to treat children with autism spectrum disorders (ASD). It has shown that the children are attracted to robots, raising the promise that appropriately designed robots could play an important role in their treatment," says Nilanjan Sarkar, associate professor of mechanical engineering at Vanderbilt University.

"However, the efforts so far have been quite limited because they haven't had a way to monitor the emotional state of the children, which would allow the robot to respond automatically to their reactions," Sarkar added.

Over the last five years, Sarkar has developed a method that uses physiological measurements, including heart rate, galvanic skin response, temperature and muscle response, to monitor the emotional state of individuals.

His original motivation was to improve human-robot interactions. However, when his nephew was diagnosed with autism, Sarkar got the idea of applying the technique to aid children with ASD.

Sarkar teamed-up with Wendy Stone, professor of paediatrics and investigator at Vanderbilt's Kennedy Center, to develop this new approach.

In a study of six teenagers with ASD, Sarkar attached a battery of physiological sensors to the participants and let play Pong or Nerf basketball with his robot.