Low-cost Eye Tracking System Research Articles

Automatic pupil detection and gaze estimation using the vestibulo-ocular reflex in a low-cost eye-tracking setup

Automatic eye tracking is of interest for interaction with people suffering from amyotrophic lateral sclerosis, for using the eyes to control a computer mouse, and for controlled radiotherapy of uveal melanoma. It has been speculated that gaze estimation accuracy might be improved by using the vestibulo-ocular reflex. This involuntary reflex results in slow, compensatory eye movements, opposing the direction of head motion. We therefore hypothesised that leaving the head to move freely during eye tracking must produce more accurate results than keeping the head fixed, only allowing the eyes to move. The purpose of this study was to create a low-cost eye tracking system that incorporates the vestibulo-ocular reflex in gaze estimation, by keeping the head freely moving. The instrument used comprised a low-cost head-mounted webcam which recorded a single eye. Pupil detection was fully automatic and in real time with a straightforward hybrid colour-based and model-based algorithm, despite the lower-end webcam used for recording and despite the absence of direct illumination. A model-based algorithm and an interpolation-based algorithm were tested in this study. Based on mean absolute angle difference in the gaze estimation results, we conclude that the model-based algorithm performed better when the head was not moving and equally well when the head was moving. With most deviations of the points of gaze from the target points being less than 1° using either algorithm when the head is moving freely, it can be concluded that our setup performs fully within the 2° benchmark from literature, whereas deviations when the head was not moving exceeded 2°. The algorithms used were not previously tested under passive illumination. This was the first study of a low-cost eye-tracking setup taking into account the vestibulo-ocular reflex.

An Intelligent and Low-Cost Eye-Tracking System for Motorized Wheelchair Control.

In the 34 developed and 156 developing countries, there are ~132 million disabled people who need a wheelchair, constituting 1.86% of the world population. Moreover, there are millions of people suffering from diseases related to motor disabilities, which cause inability to produce controlled movement in any of the limbs or even head. This paper proposes a system to aid people with motor disabilities by restoring their ability to move effectively and effortlessly without having to rely on others utilizing an eye-controlled electric wheelchair. The system input is images of the user’s eye that are processed to estimate the gaze direction and the wheelchair was moved accordingly. To accomplish such a feat, four user-specific methods were developed, implemented, and tested; all of which were based on a benchmark database created by the authors. The first three techniques were automatic, employ correlation, and were variants of template matching, whereas the last one uses convolutional neural networks (CNNs). Different metrics to quantitatively evaluate the performance of each algorithm in terms of accuracy and latency were computed and overall comparison is presented. CNN exhibited the best performance (i.e., 99.3% classification accuracy), and thus it was the model of choice for the gaze estimator, which commands the wheelchair motion. The system was evaluated carefully on eight subjects achieving 99% accuracy in changing illumination conditions outdoor and indoor. This required modifying a motorized wheelchair to adapt it to the predictions output by the gaze estimation algorithm. The wheelchair control can bypass any decision made by the gaze estimator and immediately halt its motion with the help of an array of proximity sensors, if the measured distance goes below a well-defined safety margin. This work not only empowers any immobile wheelchair user, but also provides low-cost tools for the organization assisting wheelchair users.

Evaluation of a Low-cost Eye Tracking System for Computer Input

Eye tracking technology has become one of the most popular techniques within the human and computer interaction (HCI) era, this is especially important research for people which have difficulty with speech and movement disabilities. The primary function of this technology is based on a device that tracks the movement of the eye to identify a position or scan a display. Suitable devices for eye movement can then be integrated in concordance with the requirements of the organization. Currently, eye tracking devices are becoming increasingly cheaper which make them an interesting resource for research. Although numerous studies have been conducted involving applications of eye tracking with a low-cost device, few studies have compared the actual eye tracking systems themselves. This paper empirically evaluated the performance of three independent low-cost eye tracking devices, Gazepoint’s GP3, EyeTribe, and DIY (Do-It-Yourselt). The performance evaluation used a multi-directional point-select task based on visual searching and selection to change the ground colour of a circular menu conforming to ISO 9241-9 standards for computer pointing devices. Results indicated that the spatial accuracy and speed were a good reflection of targeted tracking of errors, completion time and throughput. Consequently, the experiment with the target task showed that all devices can be a potentially valuable resource for human computer interaction research. Additionally, this basic result will be used to develop an advanced system for Thai text entry to aid communication for handicapped users.

Investigating the Potential of Optical Head-Mounted Displays as the Next Generation Device for Augmentative and Alternative Communication

In this study, we propose a wearable device such as an optical head-mounted display (OHMD) system as a promising technological solution as the next generation device for augmentative and alternative communication (AAC), which is affordable and easily customizable. This paper presents the development, implementation and evaluation of our proposed OHMD system in a two-phased study. In Phase I, we focused on developing a prototype of the law-cost OHMD system using an opensource eye-tracking software platform called EyeCan. Then, we interviewed three experts to gather opinions about the potential of the OHMD system in AAC. In Phase II, we improved technical functionalities of the OHMD system developed in Phase I, and conducted a usability study with ten participants to verify the accuracy and usefulness of our proposed OHMD system. Overall, this study demonstrates the feasibility of rapid development of a low-cost eye-tracking system for AAC users. In conclusion, our proposed OHMD system can be potentially applied in AAC, and we call for more research into integrating recent advances in emerging technologies to develop affordable, user-friendly, and personalized AAC systems.

Eye-tracking capabilities of low-cost EOG system.

This paper presents the design and implementation of a low-cost eye tracking system that allows measuring the rotational angle of the eye and gaze direction in healthy individuals. The system consists of an EOG circuit with simple components that acquire both horizontal and vertical eye movement through regular all-purpose contact electrodes. Then the data are analyzed and translated into corresponding angle values representing the eye rotation angle in both orientations. Results show that horizontal angle measurements are much more accurate than vertical measurements. A discussion regarding the performance and possible improvements is presented.

Building a Low-Cost Eye-Tracking System

This paper presents the developing of a low-cost eye-tracking system by modifying the commercial-over-the-shelf camera to integrate with the proper-tuned open source drivers and the user-defined application programs. The system configuration is proposed and the gaze-tracking approximated by the least square polynomial mapping is described. Comparisons between other low-cost systems as well as commercial system are provided. Our system obtained the highest image capturing rate of 180 frames per second, and the ISO 9241-Part 9 test performance favored our system, in terms of Response time and Correct response rate. Currently, we are developing gaze-tracking accuracy application. The real time gaze-tracking and the Head Movement Estimation are the issues in future work.

How to Build a Low-Cost Eye-Tracking System

Eye tracking, previously the purview of well-funded laboratories, is now available to any individual who wishes to study gaze patterns. Advances in eye-tracking technology have made it possible for those with meager budgets but an abundance of motivation to engage in studies that examine participants’ eye movements and fixations. This article presents a how-to guide for creating low-cost eye-tracking solutions and includes discussion of optical hardware, tracking software, and data analysis programs. The wider availability of eye-tracking technology ensures that the broader scientific community has access to techniques that can inform design and enhance research.