A Review on Different HMI Technologies for Digital Systems

Abstract

A key component in improving the usability and accessibility of digital systems is Human-Machine Interfaces (HMIs). Particularly for digital display systems, eye movement-based HMIs provide a fresh and user-friendly method of interacting with technology. These technologies improve accessibility and user experience by controlling and manipulating digital material by taking use of the natural gaze behavior. The concepts, procedures, difficulties, and uses of eye-tracking technology in HMIs are reviewed in this study. The study highlights the revolutionary potential of these systems in both assistive and mainstream applications by summarizing important research contributions, identifying hardware and software developments, assessing usability, and discussing future possibilities. From manual controls to complex mechanisms, Human-Machine Interface (HMI) systems have developed to accommodate a variety of users, including people with physical limitations. Digital display interaction has been dominated by conventional manual technologies like keyboards, mouse, and touchscreens. Alternative techniques, such as eye-tracking, voice control, and adapted gadgets, have been created for those without hands. This examination of the literature looks at the development and history of manual HMI systems, the difficulties people without hands have using conventional interfaces, and the latest technological advancements that provide accessible options. The evaluation identifies areas that need more investigation to provide fair access to digital systems while also highlighting advancements in inclusive design.

Introduction

The document explores the rapid evolution of digital display technologies and the growing need for more accessible and intuitive Human-Machine Interfaces (HMIs). Traditional manual input systems like keyboards, mice, and touchscreens, while accurate and efficient, exclude users with physical disabilities. In response, adaptive technologies such as foot-controlled mice, sip-and-puff systems, and voice-assisted keyboards have emerged, but limitations remain.

A key focus is on eye-tracking technology, a promising, hands-free HMI that uses infrared lighting, video tracking, and machine learning to interpret gaze and enable interaction. These systems are particularly valuable for individuals with mobility impairments and have applications across fields such as assistive technology, gaming, marketing, and medical diagnostics. Despite their benefits, challenges like user fatigue, accuracy issues, high costs, environmental sensitivity, and privacy concerns limit widespread adoption.

The literature review highlights the evolution of manual systems, the strengths and limitations of these traditional interfaces, and the development of alternative interaction methods like:

• Voice control systems (e.g., Siri, Alexa),

• Eye-tracking interfaces (e.g., dwell-time and blink-based control),

• Brain-computer interfaces (BCIs),

• Adaptive wearable devices (e.g., head-mounted pointers).

Several studies are reviewed:

• Duchowski (2007) provided foundational eye-tracking methods.

• Majaranta & Räihä (2002) enhanced gaze interaction through dwell-time optimization.

• Wolpaw et al. (2002) pioneered BCIs.

• Calvo et al. (2019) developed assistive gaze-based keyboards.

• Kumar et al. (2016) created blink-controlled systems.

• Stokkermans et al. (2021) addressed ethical and privacy concerns.

• Arai et al. (2020) emphasized cost-effective design.

• Krafka et al. (2016) integrated deep learning for improved gaze tracking.

The synthesis concludes that while technological advances have made HMIs more inclusive, technical, financial, and ethical challenges remain. Continued innovation in system integration, hardware design, and algorithm development is essential for building equitable, hands-free HMI solutions that work in diverse real-world contexts.

Conclusion

The advent of human-machine interfaces (HMIs) controlled by eye movements represents a transformative step in the evolution of accessible and efficient technology. These systems leverage natural gaze behaviors, allowing hands-free operation of digital displays, thereby empowering users with diverse physical capabilities. By synthesizing technological advancements, usability studies, and real-world applications, this review underscores the potential of eye-tracking systems to revolutionize interactions across various domains.First, the foundational technologies underlying gaze-controlled HMIs, such as Pupil-Corneal Reflection (PCR) and Video-Oculography (VOG), have demonstrated remarkable progress. These methodologies enable precise tracking of eye movements, providing the core functionality for such interfaces. However, challenges related to calibration complexity, environmental sensitivity, and user fatigue remain, emphasizing the need for continuous refinement. Second, the applications of eye-tracking HMIs are far-reaching. From assistive technologies that enhance the quality of life for individuals with disabilities Third, while the benefits of gaze-based HMIs are undeniable, ethical and cost-related considerations cannot be overlooked. The collection and processing of biometric data raise significant privacy concerns, as discussed by Stokkermans et al. (2021). Ensuring informed consent and robust data security protocols is imperative to maintaining user trust. Furthermore, the high costs associated with eye-tracking hardware limit accessibility for underserved populations. Addressing these barriers is crucial to achieving equitable adoption of such technologies.Lastly, the future of gaze-controlled HMIs lies in interdisciplinary collaboration and innovation. Emerging trends such as deep learning-based gaze estimation (Krafka et al., 2016) and integration with wearable devices (Holmqvist et al., 2015) promise to enhance system robustness and usability. By prioritizing affordability, ethical considerations, and multimodal interaction capabilities, researchers and developers can unlock the full potential of these interfaces. Ultimately, eye-tracking HMIs embody the convergence of technology and human behavior, offering a glimpse into a more inclusive and intuitive digital future.

References

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Copyright

Copyright © 2025 Prof. J. Wankhede, Akanksha Nethwal, Sakshi Junghare, Yadneshwari Bhakre, Kashish Nate, Vidhi Dambhare. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.