Advances in Materials, Sensors, and Integrated Systems for Monitoring Eye Movements

Abstract

Eye movements show primary responses that reflect humans' voluntary intention and conscious selection. Because visual perception is one of the fundamental sensory interactions in the brain, eye movements contain critical information regarding physical/psychological health, perception, intention, and preference. With the advancement of wearable device technologies, the performance of monitoring eye tracking has been significantly improved. It also has led to myriad applications for assisting and augmenting human activities. Among them, electrooculograms, measured by skin-mounted electrodes, have been widely used to track eye motions accurately. In addition, eye trackers that detect reflected optical signals offer alternative ways without using wearable sensors. This paper outlines a systematic summary of the latest research on various materials, sensors, and integrated systems for monitoring eye movements and enabling human-machine interfaces. Specifically, we summarize recent developments in soft materials, biocompatible materials, manufacturing methods, sensor functions, systems' performances, and their applications in eye tracking. Finally, we discuss the remaining challenges and suggest research directions for future studies.

Continuous Biopotential Monitoring via Carbon Nanotubes Paper Composites (CPC) for Sustainable Health Analysis

“…Also, PU was cured at room temperature for 3 h. After curing, the mold was cooled at room temperature for 10 min ( Figure S6 ). Figure 2 b shows the flexibility of paper-based electrodes after the MWCNTs coatings [ 20 ], which was sufficient to accommodate human skin deformations. Also, the top and side views of polymer-coated CPC electrodes are presented in Figure 2 b, showing that the polymer-coated CPC electrode was fully covered with PDMS.…”

Solvent-Free and Cost-Efficient Fabrication of a High-Performance Nanocomposite Sensor for Recording of Electrophysiological Signals

“…The development of soft and flexible wearable sensors has attracted attention due to the mechanical compatibility of such sensors with soft and stretchable tissue, electrical conductivity, and biocompatibility. Such wearable sensors, when integrated with electronic circuits, provide a promising platform for human-machine interface, rehabilitation, medical diagnosis, and continuous health monitoring [1][2][3][4][5][6][7][8]. To create a conformable and robust interface between the sensor and soft, dynamic human skin, various approaches have been implemented, including exploiting deformable structures and employing intrinsically flexible materials [9][10][11][12][13][14][15].…”

Soft Wireless Headband Bioelectronics and Electrooculography for Persistent Human–Machine Interfaces

“…As one of the technologies for tracking eye movements by measuring the potential via the positively charged cornea and negatively charged retina, EOG has gained interest in HMI. 19 T h i s c o n t e n t i s In several papers, wearable EOG devices in the form of glasses have been used because of their easy and fast wear. For example, the conventional wearable EOG eyeglasses named JINS MEME have one electrode on the bridge of the nose and one on each of the nose pads of the eyeglasses.…”

“…However, EOG amplitude, which has an amplitude between about 0.05 and 3 mV, is quite larger than EEG amplitude. − Due to frail grip strength and issues with controlling their bodies for existing motorized wheelchair users, − there are restrictions on the use of EMG and EEG. As one of the technologies for tracking eye movements by measuring the potential via the positively charged cornea and negatively charged retina, EOG has gained interest in HMI …”

“…As one of the technologies for tracking eye movements by measuring the potential via the positively charged cornea and negatively charged retina, EOG has gained interest in HMI. 19 …”