scholarly journals Terahertz radiation in ophthalmology (review)

2021 ◽  
Vol 6 (6-1) ◽  
pp. 168-180
Author(s):  
A. G. Zabolotniy ◽  
I. A. Geiko ◽  
L. M. Balagov
Keyword(s):  
Ocular Surface ◽  
Main Part ◽  
Experimental Studies ◽  
Medical Diagnostics ◽  
Surface Structures ◽  
Thz Spectroscopy ◽  
Thz Radiation ◽  
Thz Imaging ◽  
Medical Testing ◽  
Thz Waves

Terahertz (THz) radiation is one of the new, intensively studied interdisciplinary fi elds of scientifi c knowledge, including medicine, in the fi rst decades of the 21st century. At the beginning of this article (review), in a brief form, the basic statements on THz radiation, the main parameters and properties are presented; the modern THz biophtonics technologies used in biology and medicine are considered – THz refl ectometry, THz spectroscopy methods. Then a number of directions and examples of possible use of THz technologies in biology and medicine, including pharmaceuticals, are given. The main part of the review presents the progress of experimental research and the prospects for the clinical application of medical technologies of THz spectroscopy, THz imaging, in ophthalmology in the study of the morphological and functional state of the ocular surface structures, diagnosis, medical testing, and treatment of ophthalmopathology of the ocular surface. The article concludes with a review of experimental studies on the safety of using THz waves for medical diagnostics and treatment of ophthalmopathology. In the fi nal part, the main problems and prospects of introducing medical THz technologies into the clinical practice of an ophthalmologist are considered.

scholarly journals Механизмы влияния терагерцового излучения на клетки (обзор)

2020 ◽  
Vol 128 (6) ◽  
pp. 852
Author(s):  
О.П. Черкасова ◽  
Д.С. Сердюков ◽  
А.С. Ратушняк ◽  
Е.Ф. Немова ◽  
Е.Н. Козлов ◽  
...  
Keyword(s):  
Biological Activity ◽  
Human Body ◽  
Science And Technology ◽  
Medical Diagnostics ◽  
Thz Radiation ◽  
Current State ◽  
State Of Research ◽  
Diagnostics And Therapy ◽  
Thz Waves

Terahertz (THz) radiation and related technologies are rapidly developed and find their application in different branches of science and technology, including medical diagnostics and therapy. This poses a problem of determining the safety limits of the human body exposure to THz radiation, which is closely related to a problem of biological activity of THz waves. Therefore, in this work, the current state of research in the area of THz radiation – cells interaction is overviewed.

scholarly journals Continuous-Wave THz Imaging for Biomedical Samples

2020 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Yaya Zhang ◽  
Chuting Wang ◽  
Bingxin Huai ◽  
Shiyu Wang ◽  
Yating Zhang ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Biomedical Imaging ◽  
Continuous Wave ◽  
Biological Tissues ◽  
Thz Spectroscopy ◽  
Label Free ◽  
Thz Imaging ◽  
Malignant Tumours ◽  
Advantages And Disadvantages ◽  
Imaging Application

In the past few decades, the applications of terahertz (THz) spectroscopy and imaging technology have seen significant developments in the fields of biology, medical diagnosis, food safety, and nondestructive testing. Label-free diagnosis of malignant tumours has been obtained and also achieved significant development in THz biomedical imaging. This review mainly presents the research status and prospects of several common continuous-wave (CW) THz medical imaging systems and applications of THz medical imaging in biological tissues. Here, we first introduce the properties of THz waves and how these properties play a role in biomedical imaging. Then, we analyse both the advantages and disadvantages of the CW THz imaging methods and the progress of these methods in THz biomedical imaging in recent ten years. Finally, we summarise the obstacles in the way of the application of THz bio-imaging application technology in clinical detection, which need to be investigated and overcome in the future.

Application of THz imaging for medical diagnostics

2005 ◽  
Author(s):  
H. Kitahara ◽  
M. Tani ◽  
M. Hangyo ◽  
Y. Miura ◽  
T. Sawai ◽  
...  
Keyword(s):  
Medical Diagnostics ◽  
Thz Imaging

Experimental Study on Laser Beam Sealing for Increased Format-Flexibility of Packaging Machines

2017 ◽  
Vol 871 ◽  
pp. 199-207
Author(s):  
Georg Götz ◽  
Martin Brugger ◽  
Nicholas Amthor ◽  
Christoph Richter ◽  
Gunther Reinhart
Keyword(s):  
Experimental Study ◽  
Energy Efficiency ◽  
Laser Beam ◽  
Laser Beam Welding ◽  
Experimental Studies ◽  
Surface Structures ◽  
Fibre Laser ◽  
Key Factors ◽  
Processing Technologies ◽  
Diode Pumped

Resource and energy efficiency as well as format-flexibility are important key-factors for users and manufacturers of packaging machines. These key-factors could be enhanced together due to a generally positive interconnection. For example, increased format-flexibility reduces the stand-by phases and improves the overall equipment effectiveness (OEE). One way to achieve these objectives is using more flexible processing technologies. Laser beam welding is a widespread technology in many industrial branches. Use of this technology in packaging machines for sealing is unknown and therefore the potential of this technology for increasing format-flexibility as well as resource and energy efficiency is not yet exploited. The focus of this paper is the experimental investigation of laser beam sealing with a 2 μm diode-pumped thulium fibre laser. The results of various experimental studies will be presented. The achievable sealed-seam strengths with different laser beam outputs are demonstrated. Furthermore, reasons for different peeling conditions of these sealing seams are investigated. Different materials and surface structures of the required workpiece carrier are experimentally evaluated.

Safety Considerations for Sample Analysis Using a Near-Infrared (785 nm) Raman Laser Source

2003 ◽  
Vol 57 (5) ◽  
pp. 580-587 ◽  
Author(s):  
S. D. Harvey ◽  
T. J. Peters ◽  
B. W. Wright
Keyword(s):  
Near Infrared ◽  
Energetic Material ◽  
Experimental Studies ◽  
Thermal Response ◽  
Raman Laser ◽  
Medical Diagnostics ◽  
Laser Source ◽  
Analytical Technique ◽  
Nir Laser

Raman spectroscopy is often considered a nondestructive analytical technique; however, this is not always the case. The 300-mW 785-nm near-infrared (NIR) laser source used with many commercially available instruments has sufficient power to burn samples. This destructive potential is of special concern if the sample is irreplaceable (e.g., fine art, forensic evidence, or for in vivo medical diagnostics) or a hazardous energetic material (explosive or pyrophoric samples). This study quantifies the heat resulting from illuminating an extensive color array with a 785-nm NIR laser and relates these values to the hazards associated with Raman analysis. In general, darker colors were found to be more problematic. Since visible colors are not ideally correlated with absorptive characteristics at 785 nm, predictions based on thermography are not perfect; however, this approximation gives a useful method for predicting the thermal response of unknown samples to NIR exposure. Additionally, experimental studies evaluated the analysis of flammable organic solvents, propellants, military explosives, mixtures containing military explosives, shock-sensitive explosives, and gunpowders (i.e., smokeless, black, and Pyrodex powders). Safety guidelines for analysis are presented.

scholarly journals Organic crystal-based THz source for complex refractive index measurements of window materials using single-shot THz spectroscopy

2021 ◽  
Vol 127 (11) ◽  
Author(s):  
Lufan Du ◽  
Franz Roeder ◽  
Yun Li ◽  
Mostafa Shalaby ◽  
Burgard Beleites ◽  
...  
Keyword(s):  
Refractive Index ◽  
Complex Refractive Index ◽  
Accurate Determination ◽  
Laser Pulses ◽  
Thz Spectroscopy ◽  
Thz Radiation ◽  
Single Shot ◽  
Detection Scheme ◽  
Electro Optic

AbstractWe employed N-benzyl-2-methyl-4-nitroaniline (BNA) crystals bonded on substrates of different thermal conductivity to generate THz radiation by pumping with 800 nm laser pulses. Crystals bonded on sapphire substrate provided four times more THz yield than glass substrate. A pyrodetector and a single-shot electro-optic (EO) diagnostic were employed for measuring the energy and temporal characterisation of the THz pulse. Systematic studies were carried out for the selection of a suitable EO crystal, which allowed accurate determination of the emitted THz spectrum from both substrates. Subsequently, the THz source and single-shot electro-optic detection scheme were employed to measure the complex refractive index of window materials in the THz range.

scholarly journals Spectroscopic Analysis of Melatonin in the Terahertz Frequency Range

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4098 ◽  
Author(s):  
Uroš Puc ◽  
Andreja Abina ◽  
Anton Jeglič ◽  
Aleksander Zidanšek ◽  
Irmantas Kašalynas ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Active Pharmaceutical Ingredient ◽  
Pharmaceutical Products ◽  
Pharmaceutical Product ◽  
Thz Spectroscopy ◽  
Terahertz Frequency ◽  
Thz Imaging ◽  
Pharmaceutical Ingredients ◽  
Indispensable Tool ◽  
First Time

There is a need for fast and reliable quality and authenticity control tools of pharmaceutical ingredients. Among others, hormone containing drugs and foods are subject to scrutiny. In this study, terahertz (THz) spectroscopy and THz imaging are applied for the first time to analyze melatonin and its pharmaceutical product Circadin. Melatonin is a hormone found naturally in the human body, which is responsible for the regulation of sleep-wake cycles. In the THz frequency region between 1.5 THz and 4.5 THz, characteristic melatonin spectral features at 3.21 THz, and a weaker one at 4.20 THz, are observed allowing for a quantitative analysis within the final products. Spectroscopic THz imaging of different concentrations of Circadin and melatonin as an active pharmaceutical ingredient in prepared pellets is also performed, which permits spatial recognition of these different substances. These results indicate that THz spectroscopy and imaging can be an indispensable tool, complementing Raman and Fourier transform infrared spectroscopies, in order to provide quality control of dietary supplements and other pharmaceutical products.

Application of Terahertz Spectroscopy and Imaging

2010 ◽  
Vol 5 (4) ◽  
pp. 123-129
Author(s):  
Mu Kaijun ◽  
Zhang Cunlin
Keyword(s):  
Time Domain ◽  
Quartz Crystal ◽  
Terahertz Spectroscopy ◽  
Thz Radiation ◽  
Radiation Polarization ◽  
Air Plasma ◽  
Thz Imaging ◽  
Terahertz Time Domain Spectroscopy ◽  
Security Applications ◽  
Angle Of Rotation

We examined the feasibility of Terahertz time-domain spectroscopy (THz-TDS) using a 4-mm-thick quartz crystal to extract the angle of rotation of THz radiation polarization induced by a two-color laser in air plasma. We also used the THz-TDS technique to identify explosives and melamine in mixtures. In addition, we presented a new opto-mechanical scanner for security applications using the method of passive THz imaging

The Processing of Musical Prosody by Musical and Nonmusical Children

1992 ◽  
Vol 10 (1) ◽  
pp. 93-125 ◽  
Author(s):  
Claire Gérard ◽  
Catherine Auxiette
Keyword(s):  
Cognitive Processes ◽  
Musical Training ◽  
Experimental Studies ◽  
Surface Structures ◽  
The Other ◽  
Music Production ◽  
Simple Sentences ◽  
Verbal Production ◽  
Better Than

The surface structures of music and speech should coincide in musical prosody. Two processing systems have thus to be integrated, one devoted to the surface structure of speech, the other to that of music. This article is in two parts: a review of data on speech and music production and hearing, and two experimental studies on the synchronization between a rhythm and spoken sounds. In the first part, a comparison between some intensity and timing parameters that characterize the unfolding of spoken strings and of musical sequences is presented. Data from studies on performers (speakers, musicians) and listeners are compared with regard to spontaneous rates, location and duration of pauses, duration of sounds, and periodic occurrence of accents. In the second part, the ability to control the correspondence between taps and words is examined. Two experimental studies on 6-year-old children focus on the role of musical training. The reproductions of simple rhythms and simple sentences or onomatopoeias were analyzed as well as the coordination between a rhythmic sequence of taps and a spoken string. Young musicians succeeded better than nonmusicians of the same age in the synchronization between their verbal production and their motor accompaniment, mainly because they more markedly anticipated the musical string in which they integrated the spoken sounds subsequently. The results are discussed in relation to the acoustic, motor, and cognitive processes involved in the coordination of the two temporal strings.

scholarly journals Monitoring fungus infestation of common beech wood using terahertz radiation

Holzforschung ◽  
2020 ◽  
Vol 74 (7) ◽  
pp. 635-641
Author(s):  
Kirsti Krügener ◽  
Jan Ornik ◽  
Roksana Jachim ◽  
Bettina Kietz ◽  
Karin Petersen ◽  
...  
Keyword(s):  
Trametes Versicolor ◽  
Construction Projects ◽  
Beech Wood ◽  
Cultural Property ◽  
Thz Radiation ◽  
Furniture Industry ◽  
Thz Imaging ◽  
Common Beech ◽  
Destructive Analysis ◽  
Non Destructive

AbstractWood is one of the most widely used materials for construction projects, in the furniture industry, as well as in the field of cultural property of valuable objects. Terahertz (THz) radiation has great potential for non-contact and non-destructive analysis of wooden materials. This article reports a study of the degree of growth of Trametes versicolor in wood samples, using THz radiation. The analysis compares the THz results to microscopic examinations of the samples, common beech incubated with T. versicolor, at different growth times. The results indicate a strong correlation between the parameters extracted from THz measurements and the progress of the fungal infestation, suggesting that THz imaging may be a valuable tool for non-contact inspection of wood.

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