Academic Research

Gaze Typing in Virtual Reality: Impact of Keyboard Design, Selection Method, and Motion

A user gaze typing in a VR environment
A user gaze typing in a VR environment: A) FOVE VR headset with an eye tracking unit, B) a virtual keyboard displayed inside the headset, C) the trigger buttons on the bike simulator, D) peddling the bike simulator moves the user along a straight road in the virtual world.

Gaze tracking in virtual reality (VR) allows for hands-free text entry, but it has not yet been explored. We investigate how the keyboard design, selection method, and motion in the field of view may impact typing performance and user experience. We present two studies of people (n = 32) typing with gaze+dwell and gaze+click inputs in VR.

In study 1, the typing keyboard was flat and within-view; in study 2, it was larger-than-view but curved. Both studies included a stationary and a dynamic motion conditions in the user's field of view.

Our findings suggest that:

  • Gaze typing in VR is viable but constrained.
  • Users perform best (10.15 WPM) when the entire keyboard is within-view; the larger-than-view keyboard (9.15 WPM) induces physical strain due to increased head movements.
  • Motion in the field of view impacts performance: users perform better while stationary than when in motion.
  • Gaze+click is better than dwell only (fixed at 550 ms) interaction.
Flat, Within-View Keyboard: on this flat keyboard, the user needs minimal to no head movements to focus on any key on the VKB, since it is entirely within the user's field of view. To select a character, the user first focuses on the key, then the background changes to green (A). When the key is selected either by dwell or click the background changes to yellow (B). Note: this image was captured on a desktop, the field-of-view will be smaller inside the VR headset.

Curved, Larger-than-View Keyboard: Only central 2/4 of the keyboard is within the view, 1/4 of the keyboard on both left and right sides of the keyboard are out of the view. In `A' the user is about to type character `T', this requires no head movements. In `B' the user is trying to type character `W'. Since `W' is out of the user's field of view the user is forced to turn her head to left so that `W' can be focused. Similarly, in `C' the user has entered character `O'. Since `O' was out of the user's field of view, the user had to turn her head to right to focus on the key. Note: this image was captured on a desktop, the field-of-view will be smaller inside the VR headset.
Demo - Gaze typing in virtual reality

PressTapFlick: Exploring a Gaze and Foot-based Multimodal Approach to Gaze Typing

Foot gesture recognizer
Foot gesture recognizer device
Foot gestures
Foot gesture recognizer. From left to right (1) Foot Gesture Recognition Device - Master unit: the entire circuitry of the master unit is housed inside a3D-printed container that is attached to the user’s footware. The user is executing a toe tap gesture (2) Foot Gesture Recognition Device: the master and receiver units. The master unit is attached to user’s footware, and the receiver unit is connected to the computer through USB port, and 3) Gesture Recognition: the list of foot gestures that are recognized by the device. The angular velocities indicate the speed at which the user has to tap or flick the foot to trigger a corresponding gesture.

Text entry is extremely difficult or sometimes impossible in the scenarios of situationally-induced or physical impairments and disabilities. As a remedy, many rely on gaze typing which commonly uses dwell time as the selection method. However, dwell-based gaze typing could be limited by usability issues, reduced typing speed, high error rate, steep learning curve, and visual fatigue with prolonged usage. We present a dwell-free, multimodal approach to gaze typing where the gaze input is supplemented with a foot input modality. In this multi-modal setup, the user points her gaze at the desired character, and selects it with the foot input. We further investigated two approaches to foot-based selection, a foot gesture-based selection and a foot press-based selection, which are compared against the dwell-based selection.


Enhanced Virtual Keyboard:
Enhanced Virtual Keyboard

We evaluated our system through three experiments involving 51 participants, where each experiment used one of the three target selection methods: dwell-based, foot gesture-based, and foot press-based selection. We found that foot-based selection at least matches, and likely improves, the gaze typing performance compared to dwell-based selection. Among the four foot gestures (toe tapping, heel tapping, right flick and left flick) we used in the study, toe tapping is the most preferred gesture for gaze typing. Furthermore, when using foot-based activation users quickly develop a rhythm in focusing at a character with gaze and selecting it with the foot. This familiarity reduces errors significantly.


Foot Press Sensing Device: 1) Foot Press Sensing device attached to the user’s footware. The pressure sensor is placed inside the footware. Foot Press Sensing Device: the entire circuitry is housed inside a 3D-printed container, and the force sensitive resister that senses foot press actions extends from the main circuit and is placed inside the footware. 2) An outline of how the foot press sensing device is attached to the user’s footware, and the placement of the pressure sensor inside the footware.
Foot Press Sensing Device
Foot Press Device Outline

Can Gaze Beat Touch? A Fitts' Law Evaluation of Gaze, Touch, and Mouse Inputs

Touch input
Mouse input
Gaze input
Fitts' Law Experiment: a participant performing a multi-directional point-and-select Fitts' Law task. From left to right (1) Touch Input, 2) Mouse Input, and 3) Gaze Input.

Gaze input has been a promising substitute for mouse input for point and select interactions. Individuals with severe motor and speech disabilities primarily rely on gaze input for communication. Gaze input also serves as a hands-free input modality in the scenarios of situationally-induced impairments and disabilities (SIIDs). Hence, the performance of gaze input has often been compared to mouse input through standardized performance evaluation procedure like the Fitts' Law. With the proliferation of touch-enabled devices such as smartphones, tablet PCs, or any computing device with a touch surface, it is also important to compare the performance of gaze input to touch input.

In this study, we conducted ISO 9241-9 Fitts' Law evaluation to compare the performance of multimodal gaze and foot-based input to touch input in a standard desktop environment, while using mouse input as the baseline. From a study involving 12 participants, we found that the gaze input has the lowest throughput (2.55 bits/s), and the highest movement time (1.04 s) of the three inputs. In addition, though touch input involves maximum physical movements, it achieved the highest throughput (6.67 bits/s), the least movement time (0.5 s), and was the most preferred input. While there are similarities in how quickly pointing can be moved from source to target location when using both gaze and touch inputs, target selection consumes maximum time with gaze input. Hence, with a throughput that is over 160% higher than gaze, touch proves to be a superior input modality.


Visualization of the paths on the screen along which the cursor traversed during touch, mouse, and gaze inputs respectively.
Snow
Mountains

A Fitts' Law Evaluation of Gaze Input on Large Displays Compared to Touch and Mouse Inputs

Fitts' Law Experiment on Large Displays
Fitts' Law Experiment: A participant, in an upright stance, performing a multi-directional point-and-select Fitts' Law task (1) shown on a large display. Also, an eye tracker is mounted on a tripod (2).

Gaze-assisted interaction has commonly been used in a standard desktop setting. When interacting with large displays, as new scenarios like situationally-induced impairments emerge, it is more convenient to use the gaze-based multi-modal input than other inputs. However, it is unknown as to how the gaze-based multi-modal input compares to touch and mouse inputs. We compared gaze+foot multi-modal input to touch and mouse inputs on a large display in a Fitts' Law experiment that conforms to ISO 9241-9. From a study involving 23 participants, we found that the gaze input has the lowest throughput (2.33 bits/s), and the highest movement time (1.176 s) of the three inputs. In addition, though touch input involves maximum physical movements, it achieved the highest throughput (5.49 bits/s), the least movement time (0.623 s), and was the most preferred input.

Left Image - Microsoft Surface Hub (84-inch). Right Image - The foot controller used in the gaze+foot selection method. 1 - a force sensitive resistor, microcontroller, and bluetooth module in a 3D printed case, 2 - foot interaction.
Microsoft Surface Hub
Foot Controller
Demo - Gaze input on large displays

A Gaze Gesture-Based Paradigm for Situational Impairments, Accessibility, and Rich Interactions

Gaze Gesture Recognition
Gaze Gesture Interaction: A user minimizing the browser using a gaze gesture.

Gaze gesture-based interactions on a computer are promising, but the existing systems are limited by the number of supported gestures, recognition accuracy, need to remember the stroke order, lack of extensibility, and so on. We present a gaze gesture-based interaction framework where a user can design gestures and associate them to appropriate commands like minimize, maximize, scroll, and so on. This allows the user to interact with a wide range of applications using a common set of gestures. Furthermore, our gesture recognition algorithm is independent of the screen size, resolution, and the user can draw the gesture anywhere on the target application. Results from a user study involving seven participants showed that the system recognizes a set of nine gestures with an accuracy of 93% and a F-measure of 0.96. We envision, this framework can be leveraged in developing solutions for situational impairments, accessibility, and also for implementing rich interaction paradigm.

A user draws a gesture with their eye movements, and assigns a dedicated action (e.g., minimize):
Design and draw gesture
Demo - Gaze gestures for accessible and rich interactions

DyGazePass: A Gaze Gesture-Based Dynamic Authentication System to Counter Shoulder Surfing Attacks

DyGazePass Camera Positioning and Setup
DyGazePass System Setup: Camera positioning and eye tracker alignment relative to the user and display for dynamic gaze authentication.

Shoulder surfing enables an attacker to gain the authentication details of a victim through observations and is becoming a threat to visual privacy. We present DyGazePass: Dynamic Gaze Passwords, an authentication strategy that uses dynamic gaze gestures. We also present two authentication interfaces, a dynamic and a static-dynamic interface, that leverage this strategy to counter shoulder surfing attacks. The core idea is, a user authenticates by following uniquely colored circles that move along random paths on the screen. Through multiple evaluations, we discuss how the authentication accuracy varies with respect to transition speed of the circles, and the number of moving and static circles. Furthermore, we evaluate the resiliency of our authentication method against video analysis attacks by comparing it to a gaze- and PIN-based authentication system. Overall, we found that the static-dynamic interface with a transition speed of two seconds was the most effective authentication method with an accuracy of 97.5%.

The following three images show the password selection interface, dynamic interface, and static-dynamic interfaces:
Password Selection Interface
Dynamic Interface
Static-Dynamic Interface
Demo - DyGazePass: A Gaze Gesture-Based Dynamic Authentication System

A Gaze Gesture-Based User Authentication System to Counter Shoulder-Surfing Attacks

Gaze Gesture-Based Authentication Interface
Gaze Authentication Interface: A user authenticating by following moving geometric shapes with their gaze.

Shoulder-surfing is the act of spying on an authorized user of a computer system with the malicious intent of gaining unauthorized access. Current solutions to address shoulder-surfing such as graphical passwords, gaze input, tactile interfaces, and so on are limited by low accuracy, lack of precise gaze-input, and susceptibility to video analysis attack. We present an intelligent gaze gesture-based system that authenticates users from their unique gaze patterns onto moving geometric shapes. The system authenticates the user by comparing their scan-path with each shapes' paths and recognizing the closest path. In a study with 15 users, authentication accuracy was found to be 99% with true calibration and 96% with disturbed calibration. Also, our system is 40% less susceptible and nearly nine times more time-consuming to video analysis attacks compared to a gaze- and PIN-based authentication system.

Password Sequence: If a user has selected Square-Star-Pie as a password, the user is authenticated by following each shape's path in sequence (Square → Star → Pie) without visual feedback:
Square Shape Authentication
Star Shape Authentication
Pie Shape Authentication
Demo - A Gaze Gesture-Based User Authentication System

Gaze Gesture-Based Interactions for Accessible HCI

Users with physical impairments are limited by their ability to work on computers using the conventional mouse- and keyboard-based interactions. Existing accessible technologies still have usability issues, need a lot of training, and are imprecise. We present a gaze gesture-based interaction paradigm for users with physical impairments to work on a computer by just using their eye movements. We use an eye tracker that tracks the user's eye movements. To perform an action like minimizing and maximizing an application; opening a new tab, scrolling down, refresh on a browser, etc., the user moves their eyes to make a predefined gesture. The system recognizes the gesture performed and executes the corresponding action. Users with speech impairment can also use this system to speak quick phrases by performing gestures. This is crucial when a person with speech impairment is interacting with another person who does not know sign language.
Speech Impairment Assistive Gestures: Predefined eye gestures for fast phrase synthesis (e.g., Question → Yes → Help):
Question Gesture
Yes Gesture
Help Gesture
Demo - Gaze Gesture-Based Interactions

Gaze Typing Through Foot-Operated Wearable Device

Gaze Typing, a gaze-assisted text entry method, allows individuals with motor (arm, spine) impairments to enter text on a computer using a virtual keyboard and their gaze. Though gaze typing is widely accepted, this method is limited by its lower typing speed, higher error rate, and the resulting visual fatigue, since dwell-based key selection is used. In this research, we present a gaze-assisted, wearable-supplemented, foot interaction framework for dwell-free gaze typing. The framework consists of a custom-built virtual keyboard, an eye tracker, and a wearable device attached to the user's foot. To enter a character, the user looks at the character and selects it by pressing the pressure pad, attached to the wearable device, with the foot. Results from a preliminary user study involving two participants with motor impairments show that the participants achieved a mean gaze typing speed of 6.23 Words Per Minute (WPM). In addition, the mean value of Key Strokes Per Character (KPSC) was 1.07 (ideal 1.0), and the mean value of Rate of Backspace Activation (RBA) was 0.07 (ideal 0.0). Furthermore, we present our findings from multiple usability studies and design iterations, through which we created appropriate affordances and experience design of our gaze typing system.
Virtual Keyboard Scheme
User Gaze Typing with Wearable Device
Demo - Gaze Typing Through Foot-Operated Wearable Device

Gaze-Assisted User Authentication to Counter Shoulder-surfing Attacks

A highly secured, foolproof user authentication is still a primary focus of research in the field of User Privacy and Security. Shoulder-surfing is an act of spying when an authorized user is logging into a system; it is promoted by a malicious intent of gaining unauthorized access. We present a gaze-assisted user authentication system as a potential solution counter shoulder-surfing attacks. The system comprises of an eye tracker and an authentication interface with 12 pre-defined shapes (e.g., triangle, circle, etc.) that move on the screen. A user chooses a set of three shapes as a password. To authenticate, the user follows paths of the three shapes as they move, one on each frame, over three consecutive frames. The system uses a template matching algorithms to compare the scan-path of the user's gaze with the path traversed by the shape. The system evaluation involving seven users showed that the template matching algorithm achieves an accuracy of 95%. Our study also shows that Gaze-driven authentication is a foolproof system against shoulder-surfing attacks; the unique pattern of eye movements for each individual makes the system hard to break into.
Moving Shape Authentication Sequence: A user follows three moving shapes across consecutive frames (e.g., Hexagon → Rectangle → Triangle):
Hexagon Shape
Rectangle Shape
Triangle Shape
Demo - Gaze-Assisted User Authentication

GAWSCHI: Gaze-Augmented, Wearable-Supplemented Computer-Human Interaction

Recent developments in eye tracking technology are paving the way for gaze-driven interaction as the primary interaction modality. Despite successful efforts, existing solutions to the ``Midas Touch" problem have two inherent issues: 1) lower accuracy, and 2) visual fatigue that are yet to be addressed. In this work we present GAWSCHI: a Gaze-Augmented, Wearable-Supplemented Computer-Human Interaction framework that enables accurate and quick gaze-driven interactions, while being completely immersive and hands-free. GAWSCHI uses an eye tracker and a wearable device (quasi-mouse) that is operated with the user's foot, specifically the big toe. The system was evaluated with a comparative user study involving 30 participants, with each participant performing eleven predefined interaction tasks (on MS Windows 10) using both mouse and gaze-driven interactions. We found that gaze-driven interaction using GAWSCHI is as good (time and precision) as mouse-based interaction as long as the dimensions of the interface element are above a threshold (0.60" x 0.51"). In addition, an analysis of NASA Task Load Index post-study survey showed that the participants experienced low mental, physical, and temporal demand; also achieved a high performance. We foresee GAWSCHI as the primary interaction modality for the physically challenged and a means of enriched interaction modality for the able-bodied demographics.
GAWSCHI User Setup
Wearable Foot Sensor Device
Quasi-Mouse Foot Shoe Attachment

Exploring Users' Perceived Activities in a Sketch-based Intelligent Tutoring System Through Eye Movement Data

Intelligent tutoring systems (ITS) empower instructors to make teaching more engaging by providing a platform to tutor, deliver learning material, and to assess students' progress. Despite the advantages, existing ITS do not automatically assess how students engage in problem solving? How do they perceive various activities? and How much time they spend on each activity leading to the solution? In this research, we present an eye tracking framework that, based on eye movement data, can assess students' perceived activities and overall engagement in a sketch based Intelligent tutoring system, "Mechanix." Based on an evaluation involving 21 participants, we present the key eye movement features, and demonstrate the potential of leveraging eye movement data to recognize students' perceived activities, "reading, gazing at an image, and problem solving," with an accuracy of 97.12%.
First Author: Purnendu Kaul
Sketching Activity Recognition
Mechanix Tutoring System Interface

KinoHaptics: An Automated, Haptic Assisted, Physio-therapeutic System for Post-surgery Rehabilitation and Self-care

Problem Statement: 
A carefully planned, structured, and supervised physiotherapy program, following a surgery, is crucial for the successful diagnosis of physical injuries. Nearly 50% of the surgeries fail due to unsupervised and erroneous physiotherapy. The demand for a physiotherapist for an extended period is expensive to afford, and sometimes inaccessible. With the advancements in wearable sensors and motion tracking, researchers have tried to build affordable, automated, physio-therapeutic systems, which direct a physiotherapy session by providing audio-visual feedback on patient’s performance. There are many aspects of automated physiotherapy program which are yet to be addressed by the existing systems: wide variety of patients’ physiological conditions to be diagnosed, demographics of the patients (blind, deaf, etc.,), and pursuing them to adopt the system for an extended period for self-care

KinoHaptics Sensor Belt System
Objectives and Solution:
In our research, we have built a health behavior change support system called KinoHaptics for post-surgery rehabilitation. KinoHaptics is an automated, persuasive, haptic-assisted physio-therapeutic system that provides rich vibro-haptic feedback to ensure correct movement patterns without risk of re-injury.
KinoHaptics Haptic Feedback Architecture

Evaluation & Results: Evaluated in laboratory conditions with 14 users, KinoHaptics proved to be highly intuitive, accurate, and effective at preventing accidental re-injuries while strongly motivating habit building.

Conclusion: The successful acceptance of KinoHaptics highlights the promise of automated haptic-assisted systems for extended self-care and adherence to rehabilitation programs.

Healthy Leap: An Intelligent Context-Aware Fitness System for Alleviating Sedentary Lifestyles

As people in industrialized countries enjoy modern conveniences that lead to sedentary lifestyles and decreased physical activity, they increase risks of acquiring hypokinetic diseases such as obesity and heart disease. While emerging wearable computing technologies encourage developers to create fitness mobile applications, existing solutions primarily cater to already self-motivated individuals.
HealthyLeap Context-Aware Mobile Interface
In this work, we propose Healthy Leap, a mobile-based fitness system providing an intelligent context-aware user interface for encouraging users to adopt healthier, more active lifestyles. Leveraging an Android smartphone paired with a Pebble Smartwatch, the app actively monitors situational context (location, calendar events, weather forecast, time) and sends timely, tailored physical activity reminders to break sedentary states.

Let Me Relax: Toward Automated Sedentary State Recognition and Ubiquitous Mental Wellness Solutions


Advances in ubiquitous computing technology improve workplace productivity, reduce physical exertion, but ultimately result in a sedentary work style. Sedentary behavior is associated with an increased risk of stress, obesity, and other health complications. Let Me Relax is a fully automated sedentary-state recognition framework using a smartwatch and smartphone, which encourages mental wellness through interventions in the form of simple relaxation techniques. The system was evaluated through a comparative user study of 22 participants split into a test and a control group. An analysis of NASA Task Load Index pre- and post- study survey revealed that test subjects who followed relaxation methods, showed a trend of both increased activity as well as reduced mental stress. Reduced mental stress was found even in those test subjects that had increased inactivity. These results suggest that repeated interventions, driven by an intelligent activity recognition system, is an effective strategy for promoting healthy habits, which reduce stress, anxiety, and other health risks associated with sedentary workplaces.


Framework for Accelerometer Based Gesture Recognition and Integration with Desktop Applications

Master of Science • Birla Institute of Technology and Science, Pilani, India
Accelerometer Sensor Coordinates for Gesture Recognition

This research demonstrates simplified, alternative ways of interacting with desktop applications through natural hand-based gestures. Most desktop applications are designed to receive user inputs through traditional devices like keyboards and mice. The gesture recognition framework implemented in this work leverages accelerometer data from a smartphone held in a user's hand to identify gestures in real time.

A short-distance communication protocol (Bluetooth) transmits accelerometer data from the smartphone to the desktop at a constant rate, keeping the system wireless. The received data is analyzed to recognize gestures, which are then mapped to corresponding key-press and mouse events to control desktop applications and games. This framework enriches interaction, enhances user experience through intuitive gestures, and enables more creative gameplay.

Demo - Accelerometer Based Gaming - Integration with NFS on Desktop
Demo - Accelerometer Based Painting - Integration with Windows Paint

Multi-threaded Download Accelerator With Resume Support

Visvesvaraya Technological University, Karnataka, India
Multi-threaded Download Accelerator System Architecture

Issues with Existing Protocols: When transferring files over a network, traditional systems establish a single connection with the server and transfer files sequentially. This slows data transfer speed and fails to effectively utilize available network bandwidth.

Solution: Multi-threading enables multiple independent threads to connect to the server over separate sockets, transferring different files or portions of a single file simultaneously. Additionally, server-side resume support maintains download states across abrupt disconnections, allowing downloads to resume from where they stopped rather than restarting from scratch.

Main Objectives:
  • To develop a server that can support file transfer transactions, with resume support
  • To develop a client that can provide an attractive graphical user interface to the user and help the user connect to specific systems and transfer files. Furthermore, the client must be able to maintain the status of all downloads.
  • To develop a protocol that ensures that the client can communicate with the server.
  • To incorporate multi-threading in order to improve bandwidth utilization, with proper communication amongst threads so that there is no synchronization problems or race conditions.
  • To introduce resume support by incorporating CRC checks, so that incomplete downloads can be resumed from the point where it was left off.

Graphics Editor

Graphics Editor Interface in C

Overview: Graphics Editor is a utility software that enables users to perform graphical operations like drawing geometrical figures and text. Developed completely in the C programming language, the system supports geometrical shapes including rectangles, circles, ellipses, lines, and spirals, along with transformations such as rotation, scaling, clipping, saving, and loading.

User Experience: The editor is mouse-driven with intuitive GUI icons and zero learning prerequisites. In addition, it provides rich color palettes and custom fill patterns for geometrical figures.

Linux Shell

Linux Custom Shell Interface

This project is a custom implementation of a Linux Shell that enhances functionalities offered by standard Linux shells such as Bourne, Korn, C, and Bash. The shell functions as an intermediary command interpreter between user terminal inputs and the Linux kernel.

The shell parses command lines, resolves aliases and paths across system utility directories (like /bin, /etc, or /usr/bin), and dispatches process executions efficiently.

Execution Lifecycle:
  • Displays custom terminal prompt awaiting user commands (e.g. ls <directory-name>).
  • Parses the command name, resolves utility file paths, and loads binaries into memory.
  • Forks execution, collects return codes, and re-displays prompt for next interaction.

Lex & Yacc Parser

Lex and Yacc Parser Architecture

This project involved designing and modifying custom implementations of a Lexical Analyzer (Lex) and Yacc Parser to construct a custom language interpreter on UNIX systems.

Users specify regular pattern rules to generate lexical tokens through Lex, which are then passed to the Yacc grammar parser to evaluate syntax and execute target actions.