Background: Mainly due to an increase in stress-related health problems and driven by recent technological advances in biosensors, microelectronics, computing platform, and human-computer interaction, ubiquitous physiological information will potentially transform the role of biofeedback in clinical treatment. Such technology is also likely to provide a useful tool for stress management in everyday life. The aim of this systematic review is to: (1) Classify biofeedback systems for stress management, with a special focus on biosensing techniques, bio-data computing approaches, biofeedback protocol, and feedback modality. (2) Review ways of evaluating approaches to biofeedback applications in terms of their effectiveness in stress management. Method: A systematic literature search was conducted using keywords for "Biofeedback" and "Stress" within the following databases: PubMed, IEEE Xplore, ACM, and Scopus. Two independent reviewers were involved in selecting articles. Results: We identified 103 studies published between 1990 and 2016, 46 of which met our inclusion criteria and were further analyzed. Based on the evidence reviewed, HRV, multimodal biofeedback, RSP, HR, and GSR appear to be the most common techniques for alleviating stress. Traditional screen-based visual displays remain the most common devices used for biofeedback display. Biofeedback applications are usually assessed by making both physiological and psychological measurements. Conclusions: This review reveals several challenges related to biofeedback for everyday stress management, such as facilitating user's perception and interpretating the biofeedback information, the demand of ubiquitous biosensing and display technologies, and field evaluation in order to understand the use of biofeedback in everyday environments. We expect that various emerging HCI technologies could be used to address these challenges. New interaction designs as well as biofeedback paradigms can be further explored in order to improve the accessibility, usability, comfort, engagement with, and user experience of biofeedback in everyday use.

This paper presents a Learning Analytics approach for understanding the learning behavior of students while interacting with Technology Enhanced Learning tools. In this work we show that it is possible to gain insight into the learning processes of students from their interaction data. We base our study on data collected through six laboratory sessions where first-year students of Computer Engineering at the University of Genoa were using a digital electronics simulator. We exploit Process Mining methods to investigate and compare the learning processes of students. For this purpose, we measure the understandability of their process models through a complexity metric. Then we compare the various clusters of students based on their academic achievements. The results show that the measured complexity has positive correlation with the final grades of students and negative correlation with the difficulty of the laboratory sessions. Consequently, complexity of process models can be used as an indicator of variations of student learning paths.

Light is a common ambient medium to express additional information in a peripheral and calm way, but it is also an environmental stimulant to create atmosphere, evoke moods, and provide immersive experiences. Through the design of the DeLight system, we aim to establish a biofeedback-driven lighting environment that informs users about their stress level for intervention and assists them in biofeedback relaxation training. In this study, DeLight is interfaced with a heart rate variability biofeedback system with two modes for different purposes: stress intervention and relaxation assistance. We evaluated the prototype of DeLight in two user studies. The results of the first study show that DeLight has the potential for stress intervention; the HRV biofeedback through the changes of ambient light could improve a user's awareness of stress and trigger behavioral conditioning, such as deep breathing. The results of the second study confirm that DeLight has potential as a new biofeedback interface for relaxation assistance; biofeedback through an immersive lighting environment can support physiological regulation as effectively as graphic biofeedback; it offers enhanced relaxation effects regarding both subjective experience and physiological arousal. These findings suggest that the biofeedback-driven ambient light can perform as persuasive technology in the domain of health self-management. The combination of decorative and informative aspects enables the lighting interface to offer the users a comfortable and relaxing condition for biofeedback-assisted relaxation training.

No abstract

Unwind is a musical biofeedback interface which combines nature sounds and sedative music into a form of New-Age music for relaxation exercises. The nature sounds respond to the user's physiological data, functioning as an informative layer for biofeedback display. The sedative music aims to induce calmness and evoke positive emotions. UnWind incorporates the benefits of biofeedback and sedative music to facilitate deep breathing, moderate arousal, and promote mental relaxation. We evaluated Unwind in a 2 × 2 factorial experiment with music and biofeedback as independent factors. Forty young adults performed the relaxation exercise under one of the following conditions after experiencing a stressful task: Nature sounds only (NS), Nature sounds with music (NM), and Auditory biofeedback with nature sounds (NSBFB), and UnWind musical biofeedback (NMBFB). The results revealed a significant interaction effect between music and biofeedback on the improvement of heart rate variability. The combination of music and nature sounds also showed benefits in lowering arousal and reducing self-report anxiety. We conclude with a discussion of UnWind for biofeedback and the wider potential of blending nature sounds with music as a musical interface. ARTICLE HISTORY

Abstract. Breathing techniques have been widely used as an aid in stress-reduction and relaxation exercises. Most breathing assistance systems present breathing guidance in visual or auditory forms. In this study, we explored a tactile interface of a breathing assistance system by using a shape-changing airbag. We hypothesized that it would help users perform the breathing exercise more effectively and enhance their relaxing experience. The feasibility of the tactile interface was evaluated from three aspects: stress reduction, breathing training and interface usability. The results showed that for most participants, the overall heart rate variability were improved after breathing training. Moreover, "Breathe with Touch" brought users better satisfaction during the exercise. We discuss these results and future design implications for designing tactile interfaces for breathing guidance.

Abstract.Interactive storytelling in a mixed reality environment merges digital and physical information and features. It usually uses an augmentation of the real-world and physically-based interaction to create an immersive experience that corresponds to the dramatic storyline of the interactive narrative influenced by the actions of the user. Immersiveness is a crucial aspect of such an installation, and can be influenced by multiple factors such as video, sounds, interaction and, finally, the density of all combined stimuli. We used one of the stages from our interactive ALICE installation to investigate immersiveness and its contributing factors in a between-group design with a special focus on the effects of interactivity, and the feedback and feedforward stimuli of the environment on the users' experiences. The study was carried out with 41 participants and the results showed that immersiveness not necessarily depends on the modality of stimuli, but instead on their time-density.

In this paper, the authors describe how a study of a large database of written university teacher feedback in the department of Industrial Design led to the development of a new conceptual framework for feedback and the design of a new feedback tool. This paper focuses on the translation of related work in the area of feedback mechanisms for higher education into a tailored framework for feedback in the area of Industrial Design, the translation of the existing corpus of data into indicators of feedback quality and how feedback is received and further on used by students in their learning process. The newly developed tool structures teacher feedback into very targeted and highly focused feedback dialogues between teacher and individual students tailored to their individual learning process. The tool is described in this paper with respect to conversational aspects. In the future, the tool will be used actively in Industrial Design education, also with the purpose of further investigating how the quality of written feedback evolves and redesigning educational processes around feedback tools.