Brain–computer interface (BCI) provides an interconnected pathway between the human brain and external devices and paves a potential route for mind manipulations. However, most existing BCI technologies are based on simple signal transmission and are independent of other interface devices, with limited consideration for the reliability and security of the human brain’s information interaction in complicated wireless environments. Here, we propose a deep fusion coding scheme that combines the BCI visual stimulation coding with metasurface space-time coding at the physical layer, enabling reliable and secure information transfers between the human brain and external devices. A brain space-time-coding metasurface platform is designed to implement a secure wireless communication system by using harmonic-encrypted beams. We design and fabricate a proof-of-principle prototype and experimentally show that the proposed wireless BCI scheme can establish a remote but safeguarded paradigm for human–machine interactions and intelligent metasurfaces, providing a potential direction in future secure wireless communications.

Smooth pursuit is a physiological phenomenon of human eyes, which can be used as eye-control interaction to avoid the “Midas” problem. This article describes the smooth pursuit properties of continuous variable tasks under Euclid’s algorithm. Two experiments were conducted to investigate the effects of slider speed, initial position of “plus,” and variable value position on smooth pursuit interactions. The initial position and slider speed are combined in 12 combination forms, and the variable value positions are divided into 7 cases. Then, the optimal combination forms and variable value position case are derived. Experiment 1 divided the initial position into four levels of up, down, left and right and divided the slider speed into three levels of 1 deg/s, 2 deg/s, and 3 deg/s, concluding that the optimal combination of initial position and slider speed is that the speed is 2 deg/s and initial position is up. Experiment 2 was conducted on the basis of the conclusion obtained in experiment 1. The position of the variable value was divided into seven cases according to whether the left, center, and right of the smooth pursuit track the variable value appeared. The result showed that the position of the variable value in the center had the greatest influence on the pursuit efficiency. This research has an important value for the parameter set of smooth pursuit in the case of the Euclidean algorithm, it has great guiding significance for building smooth pursuit interaction in the context of the eye-control system.

The Midas touch is reflected by the interactive feedback of interface functional elements, and a low level of spatial accuracy is related to the interaction area. This study tried to solve these two problems from the perspective of human-computer interactions and ergonomics. Two experiments were conducted to explore the optimum target size and gaze-triggering dwell time of the eye–computer interaction (ECI) system. Experimental Series 1 was used as the pre-experiment to identify the size that has a greater task completion rate. Experimental Series 2 was used as the main experiment to investigate the optimum gaze-triggering dwell time by using a comprehensive evaluation of the task completion rate, reaction time, and NASA-TLX (Task Load Index). In Experimental Series 1, the optimal element size was determined to be 256 × 256p x2. The conclusion of Experimental Series 2 was that when the dwell time is set to 600 ms, the efficiency of the interface is the highest, and the task load of subjects is minimal as well. Finally, the results of Experiment Series 1 and 2 have positive effects on improving the usability of the interface. The optimal control size and the optimal dwell time obtained from the experiments have certain reference and application value for interface design and software development of the ECI system.

Recent research proposed gaze-assisted gestures to enhance interaction within virtual reality (VR), providing opportunities for people with motor impairments to experience VR. Compared to people with other motor impairments, those with Spinal Muscular Atrophy (SMA) exhibit enhanced distal limb mobility, providing them with more design space. However, it remains unknown what gaze-assisted upper-body gestures people with SMA would want and be able to perform. We conducted an elicitation study in which 12 VR-experienced people with SMA designed upper-body gestures for 26 VR commands, and collected 312 user-defined gestures. Participants predominantly favored creating gestures with their hands. The type of tasks and participants’ abilities influence their choice of body parts for gesture design. Participants tended to enhance their body involvement and preferred gestures that required minimal physical effort, and were aesthetically pleasing. Our research will contribute to creating better gesture-based input methods for people with motor impairments to interact with VR.