Trigger motion and interface optimization of an eye-controlled human-computer interaction system based on voluntary eye blinks

Eye-controlled human-computer interaction (ECHCI) attracts attention for its human-centered, natural and direct operation characteristics. The most common ECHCI trigger motion is "gazing," which causes Midas Touch problems, lowering usability and operation experience. This paper innovatively proposed using motion combinations based on blinking as the trigger of interactive objects (IOs). Trigger motions and IO design parameters were explored on the platform consisting of Tobii eye-tracker and computer vision kits. In the motion experiment, it was concluded 2-blinks could bring a low task load and high success rate of 95%. In the IO size experiment, the larger the IO diameter, the shorter the users' response time and the higher users' interaction success rate, and 55.5 mm was the optimal setting. Based on this, it was found a larger spacing could bring higher operation efficiency, and 33.3 mm was taken as the recommended value. Based on the conclusion above, an eye-controlled multimedia player prototype was built for usability evaluation, which showed an equally high efficiency compared to mouse-controlled HCI. The findings in this paper overcame Midas Touch issues and avoided the interference of unavoidable involuntary blinking, which brought a significant increase in system robustness and has a wide range of potential applications.