Esports have highlighted both their potential for social inclusion and the accessibility challenges faced by individuals with physical disabilities. This study introduces a novel paradigm for inclusive esports by shifting game control from traditional kinematic inputs to kinetic inputs. An EMG-based control interface enables gameplay through force regulation (e.g., muscle activation and inhibition). The aim is to explore how this interface enables common gameplay mechanics among players with and without physical disabilities. User Study 1 involved 20 able-bodied participants performing competitive esports tasks to examine how EMG-based control accuracy is influenced by movement range, such as wrist and elbow motion. User Study 2 extended the investigation to eight participants with physical disabilities to compare control accuracy between disabled and able-bodied users. The findings suggest that the interface enables common gameplay mechanics for individuals who can separately control activation and inhibition of each muscle corresponding to each EMG sensor via calibration adjustment but disability-related involuntary muscle activity and unintended co-contraction remains a major challenge for the interface.

Wearable electromyography (EMG)-based control interfaces are widely used by various users including both individuals with and without physical disabilities. Since EMG-based control interfaces are unfamiliar to most users and require individually defined input detection thresholds, differences in the sense of agency among users are to be expected. This study aimed to investigate individual trends in the sense of agency when operating an unfamiliar EMG-based control interface. To this end, we utilized a task that combines the intentional binding (IB) measurement paradigm with a perceptual-motor learning task to measure task performance and implicit sense of agency during EMG operation. To classify individual trends in the sense of agency, we conducted clustering based on variations in raw IB data. We found that cluster with large variations in IB had a low implicit sense of agency, reflecting the difficulty of the interface operation in detecting muscle movements as input. In addition, an analysis of the cluster with low variability in IB suggests that participants who took longer to become familiar with the input operation exhibited higher implicit agency, while those who found the task easy exhibited lower implicit agency. These findings suggest that IB may serve as a useful measure for capturing differences in operability not reflected in task performance or explicit reports of sense of agency.

Esports strengthen connections with society for people with disabilities. However, due to the competitive nature of the gaming industry, many games are not sufficiently playable for individuals with upper limb disabilities. Additionally, unlike non-esports games, esports involves competition through gaming, which means that unconditional assistance for players with disabilities can evoke a sense of unfairness among able-bodied players. To address this problem, we propose an esports support method for players with upper limb disabilities that provides skill assistance based on pre-training. The proposed method is designed so that the assistance is triggered by user actions, and the degree of assistance reflects the user’s prior training. This approach aims to reduce the perceived unfairness of assistance while preserving a sense of agency. Interview survey results suggest that appropriate assistance levels can maintain this sense of agency. However, achieving complete fairness remains challenging.

In postural control, the light touch effect stabilizes posture by adding sensory cues when a part of the body, such as the fingertips, lightly touches a support surface. However, maintaining light touch can be difficult depending on individual characteristics and task difficulty. To address this challenge, we previously proposed a system that utilizes electrical muscle stimulation (EMS) on the index finger extensor muscle to maintain light touch. The present study aims to investigate the immediate after-effects of sustained light touch through the EMS-based system on postural control. Participants performed an eyes-closed single-leg stance without touch in the pre- and post-tests and performed the same task with their index finger lightly touching a handrail between the two tests (LT-test). During the LT test, the EMS group (n=10) lightly touched the handrail while EMS was administered, and the control group (n=10) performed the light touch without EMS. The postural sway parameters and electromyography were compared within each group between pre- and post-tests. The results showed a significant difference in the center of pressure sway in the EMS group, indicating decreased postural sway immediately after the LT test. This suggests that the sustained light touch with EMS enabled users to perceive more detailed sensory cues and facilitated the subsequent retention of postural control. Moreover, the postural stability was strongly associated with pelvic stability.

When playing scales on the piano, playing all notes evenly is a basic technique to improve the quality of music. However, it is difficult for beginners to do this because they need to achieve appropriate muscle synergies of the forearm and shoulder muscles, i.e., pressing keys as well as sliding their hands sideways. In this paper, we propose a system using electrical muscle stimulation (EMS) to teach beginners how to improve their muscle synergies while playing scales. We focus on “thumb-under” method and assist with it by applying EMS to the deltoid muscle. We conducted a user study to investigate whether our EMS-based system can help beginners learn new muscle synergies in playing ascending scales. We divided the participants into two groups: an experimental group that practiced with EMS and a control group that practiced without EMS. The results showed that practicing with EMS was more effective in improving the evenness of scales than without EMS and that the muscle synergies changed after practicing.

In this paper, we propose to use facial electrical stimulation to control maximal voluntary contraction (MVC) of the upper limbs. The method is based on a body mechanism in which the contraction of the masseter muscles enhances MVC of the limb muscles. Facial electrical stimulation is applied to the masseter muscles and the lips. The former is to enhance the MVC by causing involuntary contraction of the masseter muscles, and the latter is to suppress the MVC by interfering with voluntary contraction of the masseter muscles. In a user study, we used electromyography sensors on the upper limbs to evaluate the effects of the facial electrical stimulation on the MVC of the upper limbs. The experimental results show that the MVC was controlled by the facial electrical stimulation. We assume that the proposed method is useful for sports athletes because the MVC is linked to sports performance.

Muscle fatigue monitoring is important for injury prevention in sports. Previous studies have shown that wearable electromyography (EMG) sensors on limb muscles can be used to monitor the level of muscle fatigue continuously. However, there are two main problems in using these sensors for sports. One is that users wearing them create motion artifacts that affect the sensor data. The other is that the sensors disturb limb motion. To address these problems, we propose a method for estimating biceps fatigue with an e-textile headband. There is a strong correlation between frowning and jaw clenching muscle activity and the physical efforts made when exercising. Our method uses both of EMG signals of the temporal muscles and motion artifacts. The former indicate jaw clenching and the latter indicate frowning. Experimental results show that the root mean square values calculated from the headband sensor values significantly increased when biceps were fatigued.

Many studies have addressed the affective robot, a robot that can express emotion, in the field of human-robot interaction. Really useful applications, however, can only be designed if the effect of such expressions on the user are completely elucidated. In this paper, we propose a new useful application scenario for the affective robot that shares the user's experience and describe an experiment in which the user's experience is altered by the presence of the affective robot. As the stimulus, we use movie scenes to evoke 4 types of emotion: excitement, fright, depression, and relaxation. Twenty four participants watch different movies under three conditions: no robot present, with robot that offers appropriate emotional expression, and with robot that has random emotional expression. The results show that the participants watching with the appropriate emotion robot experienced stronger emotion with exciting and relaxing movies and weaker emotion with scary movies than is true without the robot. These changes in the viewer's experience did not occur when watching with the random emotion robot. From the results, we extract design points of affective robot behavior for enhancing user experience. This research is novel in terms of examining the impact of robot emotion, seen as appropriate by the viewer, on the viewer's experience.

We introduce a Japanese Kana-character entry method on touch screens for visually impaired people. Our proposal, "Move&Flick," allows the user to move a single finger in any of eight directions twice without lifting the finger on the screen to select a character; lifting the finger decides the character. The method uses radial areas with dead zones to detect each of the eight movement directions. An experiment shows that the dead zones and voice feedback let the user acquire proper finger directions in an easy learning process. The method also has an algorithm to correctly detect the change point from the first movement direction to the second movement direction. We evaluate Move&Flick in an experiment with visually impaired subjects and confirm that Move&Flick works well.

We propose shared emotional experience agents. They enhance the user's emotional experience by emotional contagion. Our experiment has 12 participants watch videos together with a robot that expresses an emotional state by body and voice. The results suggest that the affective robot will make user more excited and relaxed and make user less depressed and afraid than they view it alone.