Mélodie Vidal

Pursuits: spontaneous interaction with displays based on smooth pursuit eye movement and moving targets

Although gaze is an attractive modality for pervasive interactions, the real-world implementation of eye-based interfaces poses significant challenges, such as calibration. We present Pursuits, an innovative interaction technique that enables truly spontaneous interaction with eye-based interfaces. A user can simply walk up to the screen and readily interact with moving targets. Instead of being based on gaze location, Pursuits correlates eye pursuit movements with objects dynamically moving on the interface. We evaluate the influence of target speed, number and trajectory and develop guidelines for designing Pursuits-based interfaces. We then describe six realistic usage scenarios and implement three of them to evaluate the method in a usability study and a field study. Our results show that Pursuits is a versatile and robust technique and that users can interact with Pursuits-based interfaces without prior knowledge or preparation phase.

Pursuit calibration: making gaze calibration less tedious and more flexible

Eye gaze is a compelling interaction modality but requires user calibration before interaction can commence. State of the art procedures require the user to fixate on a succession of calibration markers, a task that is often experienced as difficult and tedious. We present pursuit calibration, a novel approach that, unlike existing methods, is able to detect the users attention to a calibration target. This is achieved by using moving targets, and correlation of eye movement and target trajectory, implicitly exploiting smooth pursuit eye movement. Data for calibration is then only sampled when the user is attending to the target. Because of its ability to detect user attention, pursuit calibration can be performed implicitly, which enables more flexible designs of the calibration task. We demonstrate this in application examples and user studies, and show that pursuit calibration is tolerant to interruption, can blend naturally with applications and is able to calibrate users without their awareness.

Wearable eye tracking for mental health monitoring

Pervasive healthcare is a promising field of research as small and unobtrusive on-body sensors become available. However, despite considerable advances in the field, current systems are limited in terms of the pathologies they can detect, particularly regarding mental disorders. In this work we propose wearable eye tracking as a new method for mental health monitoring. We provide two reviews: one of the state-of-the-art in wearable eye tracking equipment and a second one of the work in experimental psychology and clinical research on the link between eye movements and cognition. Both reviews show a significant potential of wearable eye tracking for mental health monitoring in daily life settings. This finding calls for further research on unobtrusive sensing equipment and novel algorithms for automated analysis of long-term eye movement data.

Analysing EOG signal features for the discrimination of eye movements with wearable devices

Eye tracking research in human-computer interaction and experimental psychology traditionally focuses on stationary devices and a small number of common eye movements. The advent of pervasive eye tracking promises new applications, such as eye-based mental health monitoring or eye-based activity and context recognition. These applications might require further research on additional eye movement types such as smooth pursuits and the vestibulo-ocular reflex as these movements have not been studied as extensively as saccades, fixations and blinks. In this paper we report our first step towards an effective discrimination of these movements. In a user study we collect naturalistic eye movements from 19 people using the two most common measurement techniques (EOG and IR-based). We develop a set of basic signal features that we extract from the collected eye movement data and show that a feature-based approach has the potential to discriminate between saccades, smooth pursuits, and vestibulo-ocular reflex movements.

Detection of smooth pursuits using eye movement shape features

Smooth pursuit eye movements hold information about the health, activity and situation of people, but to date there has been no efficient method for their automated detection. In this work we present a method to tackle the problem, based on machine learning. At the core of our method is a novel set of shape features that capture the characteristic shape of smooth pursuit movements over time. The features individually represent incomplete information about smooth pursuits but are combined in a machine learning approach. In an evaluation with eye movements collected from 18 participants, we show that our method can detect smooth pursuit movements with an accuracy of up to 92%, depending on the size of the feature set used for their prediction. Our results have twofold significance. First, they demonstrate a method for smooth pursuit detection in mainstream eye tracking, and secondly they highlight the utility of machine learning for eye movement analysis.

Pursuits: eye-based interaction with moving targets

Eye-based interaction has commonly been based on estimation of eye gaze direction, to locate objects for interaction. We introduce Pursuits, a novel and very different eye tracking method that instead is based on following the trajectory of eye movement and comparing this with trajectories of objects in the field of view. Because the eyes naturally follow the trajectory of moving objects of interest, our method is able to detect what the user is looking at, by matching eye movement and object movement. We illustrate Pursuits with three applications that demonstrate how the method facilitates natural interaction with moving targets.

Looking at or through?: using eye tracking to infer attention location for wearable transparent displays

Wearable near-eye displays pose interesting challenges for interface design. These devices present the user with a duality of visual worlds, with a virtual window of information overlaid onto the physical world. Because of this duality, we suggest that the wearable interface would benefit from understanding where the users visual attention is directed. We explore the potential of eye tracking to address this problem, and describe four eye tracking techniques designed to provide data about where the users attention is directed. We also propose some attention-aware user interface techniques demonstrating the potential of the eyes for wearable displays user interface management.

Pursuits: Spontaneous Eye-Based Interaction for Dynamic Interfaces

Although gaze is an attractive modality for pervasive interaction, real-world implementation of eye-based interfaces poses significant challenges. In particular, user calibration is tedious and time consuming. Pursuits is an innovative interaction technique that enables truly spontaneous interaction with eye-based interfaces. A user can simply walk up to the screen and readily interact with moving targets. Instead of being based on gaze location, Pursuits correlates eye pursuit movements with objects dynamically moving on the interface.

Loupe: a handheld near-eye display

Loupe is a novel interactive device with a near-eye virtual display similar to head-up display glasses that retains a handheld form factor. We present our hardware implementation and discuss our user interface that leverages Loupes unique combination of properties. In particular, we present our input capabilities, spatial metaphor, opportunities for using the round aspect of Loupe, and our use of focal depth. We demonstrate how those capabilities come together in an example application designed to allow quick access to information feeds.

Shynosaurs: a game of attention dilemma

Shynosaurs is a game designed to harvest the full range of the natural behaviour of the eyes. On one hand, players need to use their eyes to aim where they direct the mouse, click and drop characters into a safe zone (the cuties). This is the usual behaviour of the eyes, as sensors to gather information. On the other hand, players can choose to use their eyes to stare at and intimidate the enemies (the shynosaurs) in order to slow them down and send them away. This is also a natural behaviour of the eyes, which we sometimes use as means to win a battle of wills. The Shynosaurs game is developed with eye-tracking in mind and aims to embrace the delicate balance needed to use the eyes as both sensors and controllers.