A REMOTE GAZE TRACKING SYSTEM USING GRAY-DISTRIBUTION-BASED VIDEO PROCESSING

2012 ◽  
Vol 24 (03) ◽  
pp. 217-227 ◽  
Author(s):  
Xiao-Hui Yang ◽  
Jian-De Sun ◽  
Ju Liu ◽  
Xin-Chao Li ◽  
Cai-Xia Yang ◽  
...  
Keyword(s):  
Video Processing ◽  
Near Infrared ◽  
Tracking System ◽  
Calibration Procedure ◽  
Infrared Light ◽  
Video Frame ◽  
Light Sources ◽  
Gaze Tracking ◽  
Practical Applications ◽  
The Gaze

Gaze tracking has drawn increasing attention and applied wildly in the areas of disabled aids, medical diagnosis, etc. In this paper, a remote gaze tracking system is proposed. The system is video-based, and the video is captured under the illumination of near infrared light sources. Only one camera is employed in the system, which keeps the equipment portable for the users. The corneal glints and the pupil center, whose extraction accuracy determines the performance of the gaze tracking system, are obtained according to the gray distribution of the video frame. And then, the positions of the points on the screen that the user fixating are estimated by the gaze tracking algorithm based on cross-ratio-invariant. Additionally, a calibration procedure is necessary to eliminate the error produced by the deviation of the optical and visual axes. The proposed remote gaze tracking system has a low computational complexity and high robustness, and experiment results indicate that it is tolerant of head movement and still works well for users wearing glasses as well. Besides, the angle error of the gaze tracking system is 0.40 degree of the subjects without glasses, correspondingly, 0.48 degree of the subjects with glasses, which is comparable to most of the existing commercial systems and promising for most of the potential practical applications.

A NOVEL INFRARED GAZE TRACKING SYSTEM BASED ON NONUNIFORM INTERPOLATION

2010 ◽  
Vol 22 (03) ◽  
pp. 185-192 ◽  
Author(s):  
Jin-Yu Chu ◽  
Jian-De Sun ◽  
Xiao-Hui Yang ◽  
Ju Liu ◽  
Wei Liu
Keyword(s):  
Tracking System ◽  
Eye Gaze ◽  
Mapping Method ◽  
Research Field ◽  
Projection Algorithm ◽  
Infrared Light ◽  
Light Sources ◽  
Gaze Tracking ◽  
Pupil Center ◽  
A Charge

The gaze tracking system has become an active research field for handicapped persons as well as general people in recent years. The precise mapping method plays an important role in the system. In this paper, a novel infrared gaze tracking system based on nonuniform interpolation is proposed. In this system, the eye images for the computer to analyze are extracted under two infrared light sources and a charge-coupled device camera, and the users do not require wearing any device. First, the integral projection algorithm and canny edge detection are applied to extract the pupil boundary points from the captured eye images, and then the pupil center is computed using an efficient and accurate ellipse-fitting algorithm. Finally, to estimate where the user looks, a novel mapping method based on the nonuniform interpolation algorithm is proposed. In this mapping method, the complicated geometric eyeball model and the nonlinear mapping between the pupil center coordinates and computer monitor screen coordinates do not need to be taken into account. Experimental results show that the proposed mapping method is simple, fast and more accurate. Moreover, our system is the remote eye gaze tracking system. The users do not need to wear any device, which make the users feel more comfortable.

The Chemistry of Single-Walled Nanotubes

MRS Bulletin ◽  
2009 ◽  
Vol 34 (12) ◽  
pp. 950-961 ◽  
Author(s):  
Michael S. Strano ◽  
Ardemis A. Boghossian ◽  
Woo-Jae Kim ◽  
Paul W. Barone ◽  
Esther S. Jeng ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Electrical Transport ◽  
Near Infrared ◽  
Scientific Discovery ◽  
Electronic Devices ◽  
Fluorescent Sensors ◽  
Infrared Light ◽  
Practical Applications ◽  
On Chip ◽  
Walled Carbon Nanotubes

AbstractThe unique structural, electronic, and mechanical properties of single-walled carbon nanotubes (SWNTs) have opened the doors to developments that push the limits of science. These advancements not only further scientific discovery, but also result in the development of everyday practical applications. These applications vary from singlemolecule sensors to nano-scaled transistors to multi-modal biosensors. This article focuses on three distinct developments made as a result of recent advances in spectroscopy of SWNTs. The first system examines the use of SWNTs for molecular detection using near-infrared light to produce tunable fluorescent sensors that are highly photostable. The second system examines the use of a 4-hydroxybenzene diazonium reagent to sort SWNTs based on electronic structure to create on-chip modifications of nano-electronic devices. The third system characterizes nanotube networks for such applications as flexible electronics, exploring the irreversible binding of adsorbates onto nanotube networks using electrical transport and Raman spectroscopy.

scholarly journals Microscale optoelectronic infrared-to-visible upconversion devices and their use as injectable light sources

2018 ◽  
Vol 115 (26) ◽  
pp. 6632-6637 ◽  
Author(s):  
He Ding ◽  
Lihui Lu ◽  
Zhao Shi ◽  
Dan Wang ◽  
Lizhu Li ◽  
...  
Keyword(s):  
Near Infrared ◽  
Biological Fluids ◽  
Visible Spectral Range ◽  
Infrared Light ◽  
Light Sources ◽  
Fully Integrated ◽  
Broadband Absorption ◽  
In Vivo Experiments

Optical upconversion that converts infrared light into visible light is of significant interest for broad applications in biomedicine, imaging, and displays. Conventional upconversion materials rely on nonlinear light-matter interactions, exhibit incidence-dependent efficiencies, and require high-power excitation. We report an infrared-to-visible upconversion strategy based on fully integrated microscale optoelectronic devices. These thin-film, ultraminiaturized devices realize near-infrared (∼810 nm) to visible [630 nm (red) or 590 nm (yellow)] upconversion that is linearly dependent on incoherent, low-power excitation, with a quantum yield of ∼1.5%. Additional features of this upconversion design include broadband absorption, wide-emission spectral tunability, and fast dynamics. Encapsulated, freestanding devices are transferred onto heterogeneous substrates and show desirable biocompatibilities within biological fluids and tissues. These microscale devices are implanted in behaving animals, with in vitro and in vivo experiments demonstrating their utility for optogenetic neuromodulation. This approach provides a versatile route to achieve upconversion throughout the entire visible spectral range at lower power and higher efficiency than has previously been possible.

scholarly journals Computational Laser Spectroscopy in a Biological Tissue

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
M. Gantri ◽  
H. Trabelsi ◽  
E. Sediki ◽  
R. Ben Salah
Keyword(s):  
Biological Tissue ◽  
Near Infrared ◽  
Continuous Wave ◽  
Light Transmission ◽  
Short Pulse ◽  
Control Volume ◽  
External Source ◽  
Time Dependent ◽  
Infrared Light ◽  
Light Sources

We present a numerical spectroscopic study of visible and infrared laser radiation in a biological tissue. We derive a solution of a general two-dimensional time dependent radiative transfer equation in a tissue-like medium. The used model is suitable for many situations especially when the external source is time-dependent or continuous. We use a control volume-discrete ordinate method associated with an implicit three-level second-order time differencing scheme. We consider a very thin rectangular biological-tissue-like medium submitted to a visible or a near infrared light sources. The RTE is solved for a set of different wavelength source. All sources are assumed to be monochromatic and collimated. The energetic fluence rate is computed at a set of detector points on the boundaries. According to the source type, we investigate either the steady-state or transient response of the medium. The used model is validated in the case of a heterogeneous tissue-like medium using referencing experimental results from the literature. Also, the developed model is used to study changes on transmitted light in a rat-liver tissue-like medium. Optical properties depend on the source wavelength and they are taken from the literature. In particular, light-transmission in the medium is studied for continuous wave and for short pulse.

scholarly journals Near-Infrared Photothermal Therapy Cancer Treatment Assisted with Graphene-Based Materials

2020 ◽  
Vol 2 (2) ◽  
pp. 26
Keyword(s):  
Cancer Treatment ◽  
Photothermal Therapy ◽  
Density Functional ◽  
Near Infrared ◽  
Density Functional Theory Calculation ◽  
Infrared Light ◽  
Light Sources ◽  
Near Infrared Light ◽  
New Material ◽  
Theory Calculation

Photothermal therapy is an emerging method of cancer treatment in which tumors are ablated by heating agents using near-infrared light (700–1000 nm). A semiconductor with a bandgap between 0.3–0.7 eV would, therefore, efficiently emit near-infrared light. The new “magic” material graphene has a bandgap of zero, which is advantageous with regard to designing a new material with a suitable bandgap for the emission of near-infrared light. In our investigations, using the first-principles density functional theory calculation method, we aimed to and successfully designed graphene-based materials with a direct bandgap of 0.68 eV. They have the potential to be optimal and efficient near-infrared light sources due to their narrow yet fitting bandgap. The present results open up a new avenue for the application of graphene-based materials to assist in photothermal therapy.

scholarly journals iMon

2021 ◽  
Vol 5 (4) ◽  
pp. 1-26
Author(s):  
Sinh Huynh ◽  
Rajesh Krishna Balan ◽  
JeongGil Ko
Keyword(s):  
Mobile Applications ◽  
State Of The Art ◽  
Tracking System ◽  
Tracking Error ◽  
Motion Blur ◽  
Gaze Tracking ◽  
The Gaze ◽  
Previous State ◽  
Personal Productivity ◽  
Different Sources

Gaze tracking is a key building block used in many mobile applications including entertainment, personal productivity, accessibility, medical diagnosis, and visual attention monitoring. In this paper, we present iMon, an appearance-based gaze tracking system that is both designed for use on mobile phones and has significantly greater accuracy compared to prior state-of-the-art solutions. iMon achieves this by comprehensively considering the gaze estimation pipeline and then overcoming three different sources of errors. First, instead of assuming that the user's gaze is fixed to a single 2D coordinate, we construct each gaze label using a probabilistic 2D heatmap gaze representation input to overcome errors caused by microsaccade eye motions that cause the exact gaze point to be uncertain. Second, we design an image enhancement model to refine visual details and remove motion blur effects of input eye images. Finally, we apply a calibration scheme to correct for differences between the perceived and actual gaze points caused by individual Kappa angle differences. With all these improvements, iMon achieves a person-independent per-frame tracking error of 1.49 cm (on smartphones) and 1.94 cm (on tablets) when tested with the GazeCapture dataset and 2.01 cm with the TabletGaze dataset. This outperforms the previous state-of-the-art solutions by ~22% to 28%. By averaging multiple per-frame estimations that belong to the same fixation point and applying personal calibration, the tracking error is further reduced to 1.11 cm (smartphones) and 1.59 cm (tablets). Finally, we built implementations that run on an iPhone 12 Pro and show that our mobile implementation of iMon can run at up to 60 frames per second - thus making gaze-based control of applications possible.

Semiconductor lasers and solid-state emitters as near-infrared light sources for photoacoustic spectroscopy

1983 ◽  
Vol 55 (8) ◽  
pp. 1419-1420 ◽  
Author(s):  
Yuji. Kawabata ◽  
Teiichiro. Kamikubo ◽  
Totaro. Imasaka ◽  
Nobuhiko. Ishibashi
Keyword(s):  
Solid State ◽  
Semiconductor Lasers ◽  
Photoacoustic Spectroscopy ◽  
Near Infrared ◽  
Infrared Light ◽  
Light Sources ◽  
Near Infrared Light

scholarly journals Dental Imaging With Near-Infrared Transillumination Using Random Fiber Laser

2020 ◽  
Vol 10 (4) ◽  
pp. 333-339
Author(s):  
Jiayu Guo ◽  
Yunjiang Rao ◽  
Weili Zhang ◽  
Zewen Cui ◽  
Anran Liu ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Light Source ◽  
Near Infrared ◽  
Infrared Light ◽  
Deep Penetration ◽  
Light Sources ◽  
Caries Lesion ◽  
Dental Imaging ◽  
Low Coherence ◽  
Source Selection

Abstract Contrary to the conventional detection method like radiography, the near infrared light source has been demonstrated to be suitable for dental imaging due to different reflectivity among enamel, dentin, and caries lesion. In this paper, three light sources with different bandwidths based on a transillumination method are compared. The contrast among enamel, dentin, and caries lesion is calculated in different situations. The experimental results show that the random fiber laser has the best comprehensive quality in dental imaging due to its high spectral density, low coherence, and deep penetration. This work provides a guidance for light source selection in dental imaging.

scholarly journals Photoactivation of GLUT4 translocation promotes glucose uptake via PI3-K/Akt2 signaling in 3T3-L1 adipocytes

2014 ◽  
Vol 07 (03) ◽  
pp. 1350067 ◽  
Author(s):  
Lei Huang ◽  
Longlong Gong ◽  
Xiaoxiao Jiang ◽  
Da Xing
Keyword(s):  
Insulin Resistance ◽  
Glucose Uptake ◽  
Intracellular Signaling ◽  
Near Infrared ◽  
Glucose Transporter ◽  
Mitochondrial Respiratory Chain ◽  
Akt Signaling ◽  
Infrared Light ◽  
Practical Applications ◽  
The Metabolic Syndrome

Insulin resistance is a hallmark of the metabolic syndrome and type 2 diabetes. Dysfunction of PI-3K/Akt signaling was involved in insulin resistance. Glucose transporter 4 (GLUT4) is a key factor for glucose uptake in muscle and adipose tissues, which is closely regulated by PI-3K/Akt signaling in response to insulin treatment. Low-power laser irradiation (LPLI) has been shown to regulate various physiological processes and induce the synthesis or release of multiple molecules such as growth factors, which (especially red and near infrared light) is mainly through the activation of mitochondrial respiratory chain and the initiation of intracellular signaling pathways. Nevertheless, it is unclear whether LPLI could promote glucose uptake through activation of PI-3K/Akt/GLUT4 signaling in 3T3L-1 adipocytes. In this study, we investigated how LPLI promoted glucose uptake through activation of PI-3K/Akt/GLUT4 signaling pathway. Here, we showed that GLUT4 was localized to the Golgi apparatus and translocated from cytoplasm to cytomembrane upon LPLI treatment in 3T3L-1 adipocytes, which enhanced glucose uptake. Moreover, we found that glucose uptake was mediated by the PI3-K/Akt2 signaling, but not Akt1 upon LPLI treatment with Akt isoforms gene silence and PI3-K/Akt inhibitors. Collectively, our results indicate that PI3-K/Akt2/GLUT4 signaling act as the key regulators for improvement of glucose uptake under LPLI treatment in 3T3L-1 adipocytes. More importantly, our findings suggest that activation of PI3-K/Akt2/GLUT4 signaling by LPLI may provide guidance in practical applications for promotion of glucose uptake in insulin-resistant adipose tissue.

scholarly journals Preparation of injectable hydrogel with near-infrared light response and photo-controlled drug release

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jianbo Zhao ◽  
Xingxing Liang ◽  
Hui Cao ◽  
Tianwei Tan
Keyword(s):  
Drug Release ◽  
Near Infrared ◽  
Controlled Drug Release ◽  
Proteinase K ◽  
Infrared Light ◽  
Light Sources ◽  
Cytotoxicity Test ◽  
Polyaspartic Acid ◽  
On Demand

AbstractPhoto-controlled release hydrogel provides a new strategy for treating tumours. Under the stimulation of external light sources, the ability to release the entrapped drug on time and space on demand has outstanding advantages in improving drug utilisation, optimising treatment, and reducing toxicity and side effects. In this study, a photo-controlled drug delivery system for disulphide cross-linked polyaspartic acid (PASP-SS) hydrogels encapsulating proteinase K (ProK) adsorbed with platinum nanoparticles (PtNPs) was designed. The injectable cysteamine-modified polyaspartic acid (PASP-SH) sol and PtNPs adsorbed by ProK (ProK-PtNPs) as regulatory factors were prepared. Then, ProK-PtNPs and lentinan were dissolved in the sol, and the oxidant was added to the matrix to form the gel in situ quickly after injection. Finally, the degradation of PASP-SS hydrogel by ProK and the controllability of drug release under near-infrared (NIR) light irradiation were elucidated. In vitro degradation of hydrogels and drug release experiments showed that the degradation rate of PASP-SS hydrogel significantly increased and the drug release rate increased significantly under near-infrared radiation. The results of cytotoxicity test showed that PASP-SS, ProK-PtNPs, and lentinan all had more than 90% cell survival rate on NIH3T3, and the lentinan released from the carrier obviously inhibited the proliferation of MCF7. PASP hydrogel has the potential to respond to on-demand light control.

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