scholarly journals Effect of dual‐wavelength (visible and near‐infrared) light sources on non‐contact heart rate detection

2021 ◽  
Author(s):  
H. Jung ◽  
T. T. A. Pham ◽  
S. Park
Keyword(s):  
Heart Rate ◽  
Near Infrared ◽  
Dual Wavelength ◽  
Infrared Light ◽  
Light Sources ◽  
Near Infrared Light

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.

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

A Portable and USB-Powered Device for Heart Rate Extraction of Optical Plethysmography Signal

2015 ◽  
Vol 771 ◽  
pp. 13-16
Author(s):  
Margi Sasono ◽  
Apik Rusdiarna Ip
Keyword(s):  
Heart Rate ◽  
Healthy Volunteers ◽  
Pulse Oximeter ◽  
Near Infrared ◽  
Portable Device ◽  
Infrared Light ◽  
Clinical Practices ◽  
Near Infrared Light ◽  
Rate Sensor ◽  
Main Component

Optical plethysmography technology has been used to design and develop a portable device for heart rate sensor. These device, consisting of near-infrared light-emitting diodes (LEDs) and photodetectors, offer a simple means of extraction the heart rate noninvasively on fingertip’s healthy volunteers. The acquisition signal is carried out based on the detection of the absorbance of near-infrared light in blood vessels due to heart’s pump activity. The microcontroller is used as the main component of electronics module. The communication to personal computer (PC) and power supply of device are provided by USB system. The algorithm of Fast Fourier Transform (FFT) in the software was used to generate the spectra of the signal and determine the HR of the obtained signal. The performance of developed device is tested on 10 fingertips of healthy volunteers, aged 19 to 57 years. A Pulse Oximeter commercial was used as gold standard instrument for comparison of results obtained by the designed device. In this paper the correlation analysis was applied to validate the results of both devices. The analysis show that the HR measured is positively correlated. These results show that the correlation between the HR measured by both the designed PPG device and Pulse Oximeter commercial are almost perfectly linear. Thus, the pulse signals gathered by the designed device are accurately believed to be representative of the heart activity of healthy volunteers. The validation method supports that designed device can potentially be developed as a simple, low power, and portable device for the importance of biomedical research (mainly for processing biomedical signal) and clinical practices.

scholarly journals Effective Modal Volume in Nanoscale Photonic and Plasmonic Near-Infrared Resonant Cavities

2018 ◽  
Vol 8 (9) ◽  
pp. 1464
Author(s):  
Xi Li ◽  
Joseph Smalley ◽  
Zhitong Li ◽  
Qing Gu
Keyword(s):  
Quality Factor ◽  
Near Infrared ◽  
Normalization Method ◽  
Mode Analysis ◽  
Infrared Light ◽  
Light Sources ◽  
Resonant Cavities ◽  
Near Infrared Light ◽  
Optical Cavities ◽  
Computing Platforms

We survey expressions of the effective modal volume, Veff, commonly used in the literature for nanoscale photonic and plasmonic cavities. We apply different expressions of Veff to several canonical cavities designed for nanoscale near-infrared light sources, including metallo-dielectric and coaxial geometries. We develop a metric for quantifying the robustness of different Veff expressions to the different cavities and materials studied. We conclude that no single expression for Veff is universally applicable. Several expressions yield nearly identical results for cavities with well-confined photonic-type modes. For cavities with poor confinement and a low quality factor, however, expressions using the proper normalization method need to be implemented to adequately describe the diverging behavior of their effective modal volume. The results serve as a practical guideline for mode analysis of nanoscale optical cavities, which show promise for future sensing, communication, and computing platforms.

scholarly journals Non-Contact Heart Rate Detection Based on Hand Vein Transillumination Imaging

2021 ◽  
Vol 11 (18) ◽  
pp. 8470
Author(s):  
Shuqiang Yang ◽  
Deqiang Cheng ◽  
Jun Wang ◽  
Huafeng Qin ◽  
Yike Liu
Keyword(s):  
Heart Rate ◽  
Near Infrared ◽  
Pulse Wave ◽  
Region Of Interest ◽  
Personal Identification ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Baseline Drift ◽  
Living Body ◽  
Hand Vein

Vein recognition technology identifies human vein characteristics under near-infrared light and compares it with stored vein information for personal identification. Although this has high anti-counterfeiting performance, it is possible to fabricate artificial hands that simulate vein characteristics to deceive the identity authentication system. In view of this potential deficiency, we introduced heart rate information to vein authentication, a means of living body detection, which can further improve the anti-counterfeiting effect of vein authentication. A hand vein transillumination imaging experiment was designed to prove its effectiveness. In the proposed method, a near-infrared light source is used to transilluminate the hand, and the transillumination images are collected by a common camera. Then, the region of interest is selected for gray-scale image processing, the feature value of each frame is extracted by superimposing and averaging the images, and then the one-dimensional pulse wave is drawn. Furthermore, the baseline drift phenomenon is filtered by morphological methods, and the maximum percentage frequency is determined by Fast Fourier Transform, that is, the pulse wave frequency. The heart rate value is then calculated, and finally, the stability of the heart rate detection result is evaluated. The experiment shows that the method produces accurate and stable results, demonstrating that it can provide living information (heart rate value) for vein authentication, which has great application prospects and development opportunities in security systems.

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