Method for Objectively Evaluating Psychological Stress Resulting when Humans Interact with Robots

Most of us have seen robots in movies, animations and comic book stories, so the word “robot” tends to conjure up images of fictional robots rather than the real thing. The robots in Japanese cartoons such as Astro Boy and Doraemon have human-like social skills, and their physical abilities make it possible for them to live alongside humans without any difficulties. In reality, robots are quite different from these fictional creations. At least, the robots of the early 21st century are still unable to interact smoothly with humans (Norman, 2007). Due to the large disparity between the fictional image of robots and their actual appearance, people sometimes feel stressed when confronted with robots. To facilitate smoother interactions between humans and robots, we must not only to improve the intelligence and physical ability of robots, but also find some way of evaluating the psychological stress felt by humans when they have to interact with robots. To develop robots that can interact smoothly with humans, we need to be able to ascertain the psychological and physiological characteristics of humans by evaluating and analyzing the stress they experience in everyday activities, design robots based on human characteristics, and evaluate and study these robots. In short, stress evaluation is a key requirement for the realization of smooth interactions between robots and humans. In this chapter, we discuss methods for objectively evaluating and investigating the psychological stress that people experience when interacting with robots. For the evaluation of stress, we used acceleration pulse waveforms and the saliva constituents which are biochemical stress markers. These were used to evaluate the psychological stress of a surgeon using a surgical assistant robot. A surgical assistant robot is a robot that interacts with a surgeon and is situated in contact with the patients to provide support for surgical operations. Interaction with humans is of greater importance for surgical assistant robots than for any other type of robot. A