Blink Research Articles

Instrumented Contact Lens to Detect Gaze Movements Independently of Eye Blinks.

To test on humans an eye tracker based on the use of a contact lens with active infrared sources and to evaluate whether this system can track the eye behind the eyelid. The system is made up of a scleral contact lens embedding two vertical cavity self-emitting lasers (VCSELs) remotely driven by eyewear comprised of electronics and cameras. Tests on humans were carried out on five subjects to assess performance and to determine whether the VCSEL spot could be detected behind the eyelid. The lens was worn and used without difficulty. The device allowed accurate tracking of the eye (0.83° ± 0.59°), and the VCSELs can be detected behind closed eyelids. These results confirm those previously obtained in terms of tracking and demonstrate that the device can be used safely to monitor eye movements even when the eyelids are closed. The VCSELs could be useful for a variety of applications to reduce data missed due to blinks, particularly with regard to interactive systems, fundamental studies on closed eye movements, or finding ways to improve clinical diagnostic precision for disorders of consciousness.

Design and development of an intelligent neck and head support system based on eye blink recognition for cervical dystonia

Design and development of an intelligent neck and head support system based on eye blink recognition for cervical dystonia

Eyelid Motion Tracking During Blinking Using High-Speed Imaging and Digital Image Correlation.

This study presents a novel technique to measure the motion of the eyelid during blinking. High-speed imaging and digital image correlation (DIC) were employed to monitor the eyelid during blinking in a non-invasive manner. Both spontaneous and reflex blinks were studied. A black liquid eyeliner was used to generate a speckle pattern on the surface of the eyelid. Facet motion captured through a DIC analysis software generated kinematic data for each blink. Calculations using this data set yielded information on the duration of the blink, eyelid displacements, and peak eyelid velocities. A consistent data set quantified the difference between blink types and reinforced the accuracy and repeatability of this DIC analysis method to measure the kinematics of blinking.

Synchronization-based fusion of EEG and eye blink signals for enhanced decoding accuracy

Decoding locomotor tasks is crucial in cognitive neuroscience for understanding brain responses to physical tasks. Traditional methods like EEG offer brain activity insights but may require additional modalities for enhanced interpretative precision and depth. The integration of EEG with ocular metrics, particularly eye blinks, presents a promising avenue for understanding cognitive processes by combining neural and ocular behaviors. However, synchronizing EEG and eye blink activities poses a significant challenge due to their frequently inconsistent alignment. Our study with 35 participants performing various locomotor tasks such as standing, walking, and transversing obstacles introduced a novel methodology, pcEEG+, which fuses EEG principal components (pcEEG) with aligned eye blink data (syncBlink). The results demonstrated that pcEEG+ significantly improved decoding accuracy in locomotor tasks, reaching 78% in some conditions, and surpassed standalone pcEEG and syncBlink methods by 7.6% and 22.7%, respectively. The temporal generalization matrix confirmed the consistency of pcEEG+ across tasks and times. The results were replicated using two driving simulator datasets, thereby confirming the validity of our method. This study demonstrates the efficacy of the pcEEG+ method in decoding locomotor tasks, underscoring the importance of temporal synchronization for accuracy and offering a deeper insight into brain activity during complex movements.

The Effect of Rosuvastatin on Facial Nerve Regeneration After Facial Nerve Injury: An Experimental Animal Study.

Rosuvastatin is an antihyperlipidemic statin group pharmacological agent with antioxidant, neuroprotective, and anti-inflammatory effects. In this study, we aimed to examine the functional, electrophysiological, and histopathological effects of rosuvastatin or in combination with corticosteroids on facial nerve regeneration in rats with traumatic peripheral facial paralysis (PFP). PFP was induced in 28 female Sprague Dawley rats that we divided into 4 groups: group 1, control group; group 2, methylprednisolone group; group 3, rosuvastatin group; group 4, rosuvastatin and methylprednisolone group. Electrophysiological, functional, and histopathological examinations were performed before and after the medications. Electrophysiological threshold values of group 3 and group 4 were found to be significantly lower than the control group on day 21 after treatment (P = .002, P = .001; P < .01).In the histopathological evaluation, axonal degeneration, macrovacuolization, and vascular congestion levels were compared between the groups, and a statistically significant difference was observed in group 4 compared to the control group. The recovery time of the eye corneal reflex was found to be significantly higher in the control group than in groups 3 and 4 when comparing postoperative day 1 to day 7 and postoperative day 1 to day 14. Rosuvastatin, especially when combined with methylprednisolone was found to significantly increase the facial nerve electrophysiological, functional, and histopathological recovery in injury-induced traumatic PFP.

Effect of Forward and Reverse Suturing on Nerve Regeneration Following Facial Nerve Axotomy

Background/Objectives: When the facial nerve is severed and a nerve graft is required, motor nerves are typically connected in the forward direction, while sensory nerves are connected in the reverse direction. However, there is limited research on the effects of reversing this connection, and no studies have been conducted using the same facial nerve. This study aimed to investigate the effects of forward and reverse suturing on nerve regeneration following facial nerve axotomy. Methods: The facial nerve trunk of male Sprague Dawley rats was incised to induce facial nerve injury, and autografts were sutured using both forward and reverse methods. Behavioral tests, including whisker reflex and eye blink tests, were conducted. Histological analyses, including toluidine blue staining and transmission electron microscopy (TEM), were performed to evaluate axon recovery. Results: Behavioral experiments showed signs of recovery at 3–4 weeks in both the forward and reverse suture groups, with no significant differences between the two methods (p &lt; 0.01). Histological analysis showed partial recovery by 8 weeks in both groups. Toluidine blue staining indicated a reduction in the number of axons at 4 weeks, with partial recovery at 8 weeks (p &lt; 0.001) in both groups. TEM analysis revealed that myelin fiber thickness was restored in both the forward and reverse suture groups, though it remained thinner compared to normal (p &lt; 0.01). Conclusions: Our results suggest that the direction of nerve suturing (forward vs. reverse) does not significantly impact nerve regeneration or functional recovery. Both suturing methods demonstrated similar recovery effects, with no significant differences in microstructural regeneration. Future studies should investigate the molecular mechanisms underlying nerve regeneration and extend the observation period to provide a more comprehensive understanding of this process.

When noise becomes signal: a study of blink rate using an eye tracker

PurposeAlthough blink rate is considered important for digital eye strain and dry eye conditions, its assessment has been mostly manual. This study aimed at quantifying blink rate automatically using the Eyelink 1000 Plus eye tracker and comparing it with manual counting. Additionally, blink rate was correlated with reading eye movements and reading speed. MethodsThirty participants (mean age 26.8±3.5 years; 19 females) were enrolled. An on-screen reading task for 3 minutes duration, was repeated 3 times with a 2-minute break between the repetitions. During this task, eye movements and blinks were measured through the Eyelink 1000 Plus eye tracker. The blink was also counted manually by the examiner in real time from a video feed. ResultsThe blink rate obtained by the eye tracker (median [Q1, Q3]:11.7 [6.8,15.5] blinks/min) and manual counting (11.6 [7.1, 15.4] blinks/min) were comparable (p>0.5). No significant correlations were observed between the blink rate and any of the reading eye movement parameters except saccadic amplitude (Spearman's rho, rs =0.506). No statistically significant correlation was found between the blink rate and reading speed. ConclusionThe Eyelink 1000 Plus eye tracker gives a comparable blink rate compared to that obtained through manual counting. A positive correlation between the blink rate and saccade amplitude could indicate a coupled interaction between the two mechanisms to minimize visual loss during reading. The option of using this tracker to investigate blinks in dry eye and binocular vision disorders can be further explored.

Clinically Probable Multiple System Atrophy Presenting Ptosis as an Early Manifestation

Many ocular features were found in patients with multiple system atrophy (MSA), which include dry eye, blepharospasm, eye movement problems, and blink reflex dysfunction. Some of these symptoms are associated with autonomic dysfunctions seen in MSA. We report a young clinically-probable MSA patient with bilateral ptosis at an early disease stage. Although there is no clear evidence that ptosis, in this case, was caused by abnormalities in the sympathetic cholinergic system, the selective impairment of sudomotor function implied an injured sympathetic cholinergic system secondary to MSA pathology. Ocular manifestations need more attention in clinical examinations of patients with MSA.

EEG Eye Blink Artifacts Removal with Wavelet Denoising and Bandpass Filtering

التحويل المويجي (WT) هو طريقة رياضية شائعة لاستخراج المعلومات من مصادر البيانات المختلفة. ومع ذلك ، عندما يتعلق الأمر بفصل المصدر الأعمى (BSS) ، فقد كان هناك بعض فقدان الإشارة المرتبط باستخدام WT. لمعالجة هذا الأمر ، تم استخدام خوارزمية هجينة تجمع بين ترشيح WT و Bandpass (BPF) لتصحيح الأخطاء. في هذه الدراسة ، تم اقتراح خوارزمية جديدة تستخدم مزيجًا من خوارزمية تحويل المويجات التطوري (EWT) ، والتي تسمى تقنية Wavelet De-Noising (WDT) ، وإجراء تصفية Band-Pass (BPF) للقضاء على رفرفة العين في مخطط كهربائية إشارات الدماغ (EEG). الهدف الرئيسي للخوارزمية هو إزالة إشارات EEG الناتجة عن حركات العين في قناة FP1 للحصول على إشارة EEG موثوقة. توضح النتائج أن هذا التكامل أكثر كفاءة من WT التقليدي ، كما تم تقييمه بواسطة قياسات نسبة الإشارة إلى الضوضاء (SNR) وقياسات الكثافة الطيفية للطاقة (PSD) التي تقيم كفاءة عملية الإزالة.

Accident Prevention System for Cars, Buses, Trucks

Driver drowsiness is a significant factor in road accidents, contributing to a large number of crashes annually. To enhance road safety, the development of a Drivers Drowsiness Detection System is essential. This system builds to detect early signs of lazyness in drivers and provide timely alerts to prevent accidents. The proposed system uses to track key indicators of drowsiness, such as eye closure, head position, yawning, and blink rate. By utilizing a camera-based real-time monitoring system, it continuously analyzes the driver’s facial expressions. The system employs cadcade algorithms to distinguish a featurebased object detection algorithm to detect objects from images between alert and drowsy states based on collected data. When drowsiness is detected, the system triggers alerts like audio warnings, seat vibrations, or even vehicle slowing mechanisms, depending on the integration. This technology has the potential to significantly reduce the number of road accidents related to driver fatigue and could be applied in both personal vehicles and commercial fleets. The implementation of such systems represents a critical step toward improving road safety and decreasing driver-related incidents. Nowadays it is very challenging to stay active all the time due to busy schedules. Falling asleep while driving can lead to serious consequences, accidents, and even death. This situation is much more common and therefore it is very important to solve this problem. So, to solve this problem, we developed a sleep alarm system for drivers. This system alerts the user when he falls asleep at the wheel, thus the main concern is preventing accidents and saving lives. This system is useful for long- distance travelers and late-night drivers.

High-Fidelity and High-Efficiency Talking Portrait Synthesis With Detail-Aware Neural Radiance Fields.

In this paper, we propose a novel rendering framework based on neural radiance fields (NeRF) named HH-NeRF that can generate high-resolution audio-driven talking portrait videos with high fidelity and fast rendering. Specifically, our framework includes a detail-aware NeRF module and an efficient conditional super-resolution module. Firstly, a detail-aware NeRF is proposed to efficiently generate a high-fidelity low-resolution talking head, by using the encoded volume density estimation and audio-eye-aware color calculation. This module can capture natural eye blinks and high-frequency details, and maintain a similar rendering time as previous fast methods. Secondly, we present an efficient conditional super-resolution module on the dynamic scene to directly generate the high-resolution portrait with our low-resolution head. Incorporated with the prior information, such as depth map and audio features, our new proposed efficient conditional super resolution module can adopt a lightweight network to efficiently generate realistic and distinct high-resolution videos. Extensive experiments demonstrate that our method can generate more distinct and fidelity talking portraits on high resolution (900 × 900) videos compared to state-of-the-art methods. Our code is available at https://github.com/muyuWang/HHNeRF.

Small Fiber Neuropathy in Burning Mouth Syndrome: A Systematic Review.

Burning mouth syndrome (BMS) is a chronic idiopathic orofacial pain disorder, characterized by persistent burning sensations and pain without clear pathological causes. Recent research suggests that small fiber neuropathy (SFN) may play a significant role in the neuropathic pain and sensory disturbances associated with BMS. Following PRISMA guidelines, this systematic review aims to evaluate and synthesize current evidence supporting SFN's involvement in BMS. The protocol is registered in PROSPERO (CRD42024555839). The results show eight studies reported reductions in nerve fiber density in tongue biopsies (ranging from 30% to 60%), along with morphological changes indicative of small fiber damage. Additionally, an increase in TRPV1-positive, NGF-positive, and P2X3-positive fibers, overexpression of Nav1.7, and slight underexpression of Nav1.9 mRNA were observed in BMS patients. Quantitative Sensory Testing in seven studies revealed sensory abnormalities such as reduced cool detection and cold pain thresholds. Blink reflex and corneal confocal microscopy also indicated peripheral and central small fiber damage, along with increased artemin mRNA expression. The evidence strongly supports SFN as a key factor in the pathophysiology of BMS, particularly due to reductions in nerve fiber density and altered sensory thresholds. However, variability across studies highlights the need for larger, standardized research to establish causal relationships and guide therapeutic strategies.

Comparative Analysis of Blink Rates During Printed and On-Screen Reading Across Varying Screen Sizes

Objective: To compare the blink rates during resting periods and while engaging in printed and on-screen reading across different digital screen dimensions.Material and Methods: This study involved thirty-two university students with normal vision, who were recorded during a 3-minute conversation to establish baseline blink rates and subsequently during four reading conditions. Participants read four passages under different conditions: printed text, smartphone, tablet, and computer screens. Video recordings were then analysed to quantify blink rates (blinks per minute, bpm) for each condition.Results: Blink rates significantly decreased in all reading scenarios compared to the baseline resting condition (p-value&lt;0.05). Analysis via repeated measures ANOVA demonstrated significant differences in blink rates across all reading conditions (p-value&lt;0.01). Pairwise comparisons revealed that blink rates during smartphone reading were notably lower than printed text, tablets, and computers (p-value&lt;0.05). Conversely, blink rates exhibited no significant differences between printed text and tablet, printed text and computer, and computer and tablet readings (p-value&gt;0.05).Conclusion: The study reveals a consistent decrease in blink rates during various reading conditions with different digital screens compared to resting states, highlighting the influence of visual engagement on ocular behaviour. Reading with a smartphone has decreased blink rates, which may affect eye health and device use. Understanding these dynamicscan guide ergonomic design to reduce visual discomfort from digital screen use, supporting healthy reading habits in the digital age.

AnEEG: leveraging deep learning for effective artifact removal in EEG data

In neuroscience and clinical diagnostics, electroencephalography (EEG) is a crucial instrument for capturing neural activity. However, this signal is polluted by different artifacts like muscle activity, eye blinks, environmental interference, etc., which makes it more difficult to retrieve important information from the signal. Deep learning methods have demonstrated the potential to lower these artifacts and enhance the EEG’s quality in recent years. In this work, a novel deep learning method,“AnEEG” is presented for eliminating artifacts from EEG signal. The quantitative matrices NMSE, RMSE, CC, SNR and SAR are calculated to confirm the effectiveness of the proposed model. Through this process, it was found that the suggested model outperformed wavelet decomposition techniques. The model achieves lower NMSE and RMSE values, which indicates better agreement with the original signal. Achieving higher CC values means stronger linear agreement with the ground truth signals. Additionally, the model shows improvements in both SNR and SAR values. Overall, this suggested approach showcases promising results in improving the quality of EEG data by utilizing deep learning.

Spontaneous eye blinking as a diagnostic and prognostic marker in disorders of consciousness: Protocol of an international multicentre longitudinal study.

Diagnostic and prognostic decision-making in patients with Disorders of Consciousness (DoC) is challenging. It has been suggested that spontaneous eye blink rate is an index of patients' level of consciousness easy to detect in clinical practice. Further blinking features (i.e., amplitude, duration, variability in intervals between blinks) may change as a function of cognitive load, but have not been investigated in patients with DoC. This multicentre, longitudinal study aims at exploring the diagnostic and prognostic value of spontaneous eye blinking features in DoC. Eight European medical institutions will enrol consecutively admitted adult patients with DoC. Within two weeks from study entry demographic, anamnestic and clinical data will be collected. Moreover, patients will undergo two 20-minute EEG-EOG recordings at rest, to collect blinking features and EEG activity. A clinical follow-up will be performed after 6 months. A group of healthy individuals will be enrolled for reference. Possible differences in blink features between patients and the reference group, differences across diagnostic sub-groups, and correlations between blinking features and clinical outcome will be investigated. The results of this study might help clinicians to reduce misdiagnosis rate in DoC and provide useful information for prognostication and care pathway plan.

Changes in the eye blink and half-blink rates in horses as a reaction to a stressor: A preliminary study

Changes in the eye blink and half-blink rates in horses as a reaction to a stressor: A preliminary study

Stimulated Blink Reflex Abnormalities Before And After Sport-related Concussion And Association With Self-reported Symptoms

Stimulated Blink Reflex Abnormalities Before And After Sport-related Concussion And Association With Self-reported Symptoms

Assessment Of Stimulated Blink Reflex And Symptoms Over Time In Collegiate Athletes With Sport-related Concussion

Assessment Of Stimulated Blink Reflex And Symptoms Over Time In Collegiate Athletes With Sport-related Concussion

Effect of Heating and Massaging of Meibomian Glands on Their Imaging

Background and Objectives: Infrared light is used to image the Meibomian glands through their thermal profile. This study aimed to investigate the effects of a combination of heating and an eyelid massage on Meibomian gland visibility and tear film parameters. Materials and Methods: Twenty-four participants (26 ± 6.9 years) were enrolled in this prospective study, which involved imaging the Meibomian glands of both the lower and upper eyelid and assessing the non-invasive breakup time (NIBUT), tear meniscus height (TMH), and blink rate (using the CA-800, Topcon) at baseline after five minutes of eyelid warming followed by a five-minute eyelid massage. The second session, which was randomised in sequence, repeated the same measurements but without the inclusion of any eyelid warming or massage as the control condition. Results: While there was no change in lower lid Meibomian gland appearance as a result of eyelid heating, eyelid massage, or multiple lid eversion (median 2.0, range 0.0 to 4.0; p = 0.782), there was a change in upper lid appearance 5 min after heating and lid massage (p = 0.025), but again, multiple lid eversion had no effect (p &gt; 0.05). The NIBUT decreased on second lid eversion (p = 0.049), although this was not evident on the third lid eversion (p = 0.090). The effect on NIBUT was also apparent with heating (p = 0.034 immediately after) but was sustained with 5 min of eyelid massage (p = 0.031). The TMH increased with heating (p &lt; 0.001), and this effect was sustained with 5 min of eyelid massage (p = 0.011), but there was no lid eversion effect (p &gt; 0.05). The blink rate was unaffected by heating, eyelid massage, or multiple eversions of the eyelids (median 24 blinks/min, range 8 to 59 blinks/min; p = 0.61). Conclusions: Eyelid warming can increase the visibility of the Meibomian glands, although this effect was only observed with upper lid imaging and the effect dissipated after 5 min of eyelid massage. Warming and massage also disrupt the tear film, as does multiple lid eversion, emphasising the need to use the least invasive tear film assessment techniques first.

Evaluating Users’ Perception of Biologically Inspired Involuntary Behavior in Human–Robot Interaction

Multimodal communication is a human feature that enables diverse interactions. In human–robot interaction (HRI), robots have to communicate using human skills so that they can seem natural and assist effectively. Most research uses predefined gestures to equip robots with social abilities. However, researchers scarcely consider generating bioinspired involuntary behavior to improve a robot's expressiveness and communication. Human studies revealed that involuntary behavior affects how others perceive communicative intentions. Therefore, mimicking human involuntary behavior may positively affect HRI. This article extends our previous work on equipping robots with involuntary behavior with a user study that evaluates the use of bioinspiration for complementing gestures. A preliminary test is conducted with 15 participants to determine if they can perceive the intensities of the involuntary processes heart rate, pupil size, blink rate, breathing rate, and motor activity. 63 new participants interacted with a robot with bioinspired behaviors or a robot only showing predefined gestures to evaluate the robots’ warmth, competence, and discomfort. The results show that the preliminary test participants differentiated the intensities of the involuntary processes. Participants in the second study find the robot with bioinspired behaviors significantly warmer and more competent than the robot with predefined gestures, with no discomfort difference.