Rett Syndrome is a rare neurodevelopmental disorder associated with severe intellectual and motor impairments. Among its core symptoms, children with Rett progressively lose purposeful hand use, limiting their ability to reach for, touch, and manipulate objects in the surrounding environment. Early intervention is therefore important to help maintain opportunities for functional hand use through repeated and motivating activities. To support this goal, we developed Pufff, a touch-sensitive interactive toy that provides visual feedback during touch-based interaction. Using signals acquired from a six-patch capacitive sensing array and a lightweight machine learning model, the system distinguishes three types of touch and triggers different responses accordingly. This interaction paradigm is intended to support future therapist-led activities aimed at encouraging purposeful hand use through play, while also enabling basic monitoring of touch interaction patterns. This paper presents an early implementation of the toy and demonstrates the technical feasibility of the approach.

EnhancedTouchX, a bracelet-type interpersonal body area network device, not only detects but also quantifies interpersonal hand-to-hand touch interactions. Without any wired connection, it can identify the direction and gestures of a touch. The developed device can connect to an external device via Bluetooth Low Energy for monitoring and logging where, when, how long, who, and how the touch interactions occurred. These daily augmented touch interactions provided by such contextual information would offer a variety of applications to facilitate social interactions. Our experiment, conducted with several pairs of participants, demonstrates that the devices can identify the direction of a touch (from one initiating the touch (active touch) to the one being touched (passive touch)) with 95% accuracy. In addition, the devices are also capable of identifying four types of touch gestures with 85% accuracy using a simple threshold classifier.

In this paper, we propose a computational modeling method to investigate head-eye coordination in face-to-face behavior. The method looks into probability density of individuals' head orientation during looking at others' face. We conducted experiment under two different scenarios in human-human interaction. Under each scenario, individuals' head orientation could be fitted with one Gaussian distribution. Referring to the model, it is possible to calculate several ranges of head orientation, which could be used as surrogate for estimating visual focus of attention. The model also provides theoretical support to the design of automatic systems that measure face-to-face interaction.

We present EnhancedTouch, a novel bracelet-type wearable device for facilitating human-human physical touch. In particular, we aim to support children with autism spectrum disorder (ASD), who often exhibit particular communication patterns, such as lack of physical touch. EnhancedTouch is a unique device that can measure human-human touch events and provide visual feedback to augment touch interaction. We employ personal area network (PAN) technology for communication with partner devices via modulated electrical current flowing through the users' hands. Our user study show that the visual feedback provided by the developed bracelet motivates children with ASD to touch one another. Moreover, EnhancedTouch offers a function to record the time and duration of a touch event as well as the identity of the touched person. This allows us to identify and evaluate intervention based on physical touch in a quantitative manner.

It is known that visual, auditory, and tactile modalities affect the experiences of eating and drinking. One such example is the “glug” sound and vibration from a Japanese sake bottle when pouring liquid. Our previous studies have modeled the wave of the vibration by summation of two decaying sinusoidal waves with different frequencies. In this paper, to enrich expression of various types of liquid, we included two new properties of liquid: the viscosity and the residual amount of liquid, both based on recorded data.

We developed a bed-style haptic display "Haptic Bed" that provides weight sensation to wide area of the user's body. This system comprises motors, belts, a cushion and a comforter to press and swing the user lying on the bed. Haptic Bed is a type of whole-body haptic interface, characterized by the presentation of low-frequency force with multiple degrees of freedom. The prototype system with two motors can present a weight sensation to approximately five regions of the abdomen. Although a sensation is only presented to the abdomen in this study, Haptic Bed can present a weight sensation to a wider area by increasing the number of motors. The system has the potential to enrich the audio visual experience in several ways, such as by expressing the sensation of a horrific ghost sitting on the user as part of entertainment content, or by presenting the existence of a remote relative as a telecommunication tool. Overall, the system changes a bed into a new medium through which immersive contents are presented in an immersive manner.

We present VacuumTouch, a novel haptic interface architecture for touch screens that provides attractive force feedback to the user's finger. VacuumTouch consists of an air pump and solenoid air valves that connect to the surface of the touch screen and suck the air above the surface where the user's finger makes contact. VacuumTouch does not require the user to hold or attach additional devices to provide the attractive force, which allows for easy interaction with the surface. This paper introduces the implementation of the VacuumTouch architecture and some applications for enhancement of the graphical user interface, namely a suction button, a suction slider, and a suction dial. The quantitative evaluation was conducted with the suction dial and showed that the attractive force provided by VacuumTouch improved the performance of the dial menu interface and its potential effects. At the end of this paper, we discuss the current prototype's advantages and limitations, as well as possible improvements and potential capabilities.

We present a novel photo touch sensing architecture, HACHIStack. It can measure the approaching velocity of an object and predict its contact time with the touch screen using two optical sensing layers above the surface. The photo sensing layers form three unique capabilities: high-speed sampling, velocity acquisition, and contact time prediction. This work quantitatively examines these capabilities through two laboratory experiments, and confirms that the capabilities of HACHIStack are sufficient for multimodal interaction, in particular, touch-based interaction with haptic enhancement. We then present three applications with HACHIStack: 1) chromatic percussions (xylophone and glockenspiel) with haptic feedback; 2) no-delay haptic feedback with the sensation of tapping on various simulated materials (e.g., rubber, wood and aluminum); and 3) a virtual piano instrument that allows players to perform weak and strong strokes by changing the tapping velocity.

Sensing the position and movement of the accelerator pedal in a vehicle is important for acceleration control and safety while driving. The accelerator pedal is controlled by the foot, but precise adjustment requires much training because the driver must rely on somatosensory cues, which provide limited feedback. In this study, we propose periodic tactile feedback for the accelerator pedal to provide an additional tactile cue. We conducted an experiment using a driving simulator to compare the lap time, the rate of off-track incidents and the subjective evaluation of controllability recorded in questionnaires. The experiment confirmed that the feedback makes the control of acceleration easier and facilitates safer driving.

With the aim of augmenting auditory sensation by tactile stimuli, we investigated cross-modal relationships between the two modalities, focusing on frequency. The results showed that frequency consonance between tactile and audio stimuli depends on the relationship between harmonics, in a manner similar to auditory waves, but with broader peaks.

Characters with body materials that are different from that of humans, such as metal robots or rubber people, frequently appear in movies and comics. While the abilities of their synthetic bodies can be easily observed from their actions, their somatic sensations are more difficult to appreciat e. Our aim in this work is to simulate the alteration of the material of the human body by means of vibrotactile feedback. The feedback represents the properties of the materials and is periodically applied to the elbow joint in synchrony with the elbow angle. This simulated sensation of having a different body material gives us the feeling of those characters. This technique can also be applied to improve maneuverability in the teleoperation of master-slave systems because it gives the operator a robot-like sensation.

Along public pathways, visual signs and audio cues are used by pedestrians to guide them into forming smoother pedestrian flows. However, often ignored or neglected, these signals require greater pedestrian attentiveness and appropriate conscious effort. To solve this problem, we have proposed the concept of "vection field". This is a field of optical flow that cues movement according to a pedestrian's motion. Visual stimulus within this optical flow leads pedestrians innately in specific directions without requiring direct interventions. We have implemented such a field by covering the ground with a lenticular lens screen; in this setup, neither power supply nor position tracking of pedestrians is necessary. An experimental result from our previous study shows that a vection field can direct pedestrians to one side. However, the quality of the optical flow such as image clarity and smoothness of motion was unsatisfactory in that it could cause a reduction in leading inducement. In this paper, we describe in detail a new display method involving a lenticular lens screen that yields an improvement in the quality of the vection field and ultimately pedestrian optical flow. Experiments showed improvements over previous attempts.