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A History of Thermology and Thermography
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
Other novel infrared systems were developed during World War I (1914–1918). Infrared detectors have been indispensable for night warfare since then, to help detect enemy movements and to locate wounded personnel under cover of darkness. Infrared methods could distinguish between unconscious and dead casualties by examining the surface temperature of the body from a distance. Other important WWI developments included remote temperature sensing and infrared “flying torpedo” guidance using multiple thermosensors.
Infertility Diagnosis and Treatment
Published in Sujoy K. Guba, Bioengineering in Reproductive Medicine, 2020
where λ is the wavelength, ε(λ) the emissivity equal to unity for a black body, and C1 and C2 are constants. A part of the energy is in the infrared frequency range of 2 × 1012 to 3 × 1014 Hz. Intensity of emission in the infrared range is a measure of the temperature of the body. If the emission from individual small areas of the surface of the body can be determined then the temperature profile over the body is obtained. Infrared thermography is commonly carried out by a scanning process. A single infrared detector gives an electrical output proportional to the infrared energy intensity falling on the device. Infrared emissions from small areas on the surface of the object studied are selectively focused onto the detector (Figure 4.9). One of the ways of doing so is to have scanner comprising of a moving mirror and a rotating wheel acting as a beam chopper. As infrared energy from a specific area is directed to the detector the electrical output of the detector is converted into a light intensity at the corresponding X-Y coordinate on a television monitor. If in this manner the entire surface is scanned and television monitor retains the light intensity points, a two-dimensional image representing the temperature profile is obtained.
The Human Nail: Structure, Properties, Therapy and Grooming
Published in Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters, Cosmetic Formulation, 2019
Kenneth A. Walters, Majella E. Lane
OTTER uses pulsed laser excitation to induce temperature jumps of the order of a few degrees Celsius in the top few microns of the material under study. These temperature jumps decay within microseconds and do not materially increase the average substrate temperature or the rate of diffusion under study. They are observed with a high-speed infrared detector sensitive to the heat radiation emitted by the surface (Bindra et al., 1992). For bio-tissue, this radiation is strongest in the mid-infrared 6–13 µm band of wavelengths. The measurement captures the decay dynamics of this transient component of the heat radiation and relates it to the physical properties of the near-surface layers through appropriate mathematical models. In such models, depth resolution is linked to the time parameter of the transients and chemical specificity to the absorption spectra of the molecules of interest (Imhof et al., 1994). OTTER has been used to measure nail water content, nail water concentration depth profiles and topically applied solvent penetration (Figure 5.5 ) through nail (Xiao et al., 2010, 2011). Combining the water content results with transonychial water (TOWL) flux through nail also allows the water diffusion coefficient of nail to be calculated (see section ‘Transonychial Water Loss (TOWL)’).
Applications of Fourier transform infrared spectroscopy to pharmaceutical preparations
Published in Expert Opinion on Drug Delivery, 2020
Yijie Song, Yuanhua Cong, Bing Wang, Ning Zhang
Another development of FTIR is biological sample detection [133] because of its nondestructive determination and is the inevitable future trend. Scattering near-field optical technology improves the spectral resolution, and chemometrics is applicable for extracting valid information from a huge amount of chemically specific data. Thus, FTIR can be applied to dynamic complex systems. For instance, Ashtarinezhad [144] utilized micro-FTIR to successfully recognize the fetus abnormalities after exposure to drug and the combination of PCA, ANN, and SVM to distinguish the control and treatment groups automatically. Furthermore, infrared detection has good adaptability with other methods because no additives are required for FTIR, and the same sample after detecting by FTIR can still be used in other methods. Multimodal imaging [149,150] could generate complementary chemical information from the same sample and coupling IR with other techniques would be the trend of the times.
Real-time technique for conversion of skin temperature into skin blood flow: human skin as a low-pass filter for thermal waves
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Andrey Sagaidachnyi, Andrey Fomin, Dmitry Usanov, Anatoly Skripal
The described technique is applicable to any type of temperature transducers. Arrays of infrared detectors have incomparably less inertial properties and higher spatial resolutions in two-dimensional space than those of contact sensors, but not better amplitude sensitivities. A high-resolution temperature measurement system with a sensitivity down to 0.0001 °C has been developed, which allows recording of skin temperature pulsations related to the respiratory and heart activities with amplitudes of approximately 0.005 and 0.0004 °C, respectively (Dupuis et al. 1996; Cuadras and Casas 2004). These signals have amplitudes approximately 50 times smaller than the typical sensitivities of modern cooled infrared cameras. Therefore, the high-resolution contact measurements of temperature enable the conversion of output signal into BF in the complete range of variation of vascular tone, from the lowermost endothelial to the uppermost cardiac frequency band.
The effects of extended nap periods on cognitive, physiological and subjective responses under simulated night shift conditions
Published in Chronobiology International, 2018
Heart rate was continuously monitored over each shift using the Suunto® memory belt system, Suunto, Finland. Heart rate was continuously measured and recorded on the belt, which was downloaded and analysed after each shift. The second physiological measure was tympanic temperature (Braun Thermoscan ExacTemp® Infrared detection thermometer, Braun GmbH, Kronberg, Germany), which, although not continuous and not the most accurate (when compared to rectal or core temperature), provided insights into the changes in temperature of the participants over the course of each shift. In a previous study from the same laboratory, tympanic temperature was sensitive to time of day (Davy & Göbel, 2013; Wesensten et al., 2002).