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Novel UV Filtering Agents for Next-Generation Cosmetics: From Phytochemicals to Inorganic Nanomaterials
Published in Madhu Gupta, Durgesh Nandini Chauhan, Vikas Sharma, Nagendra Singh Chauhan, Novel Drug Delivery Systems for Phytoconstituents, 2020
Electromagnetic radiation are the waves containing a vibrating electrical and magnetic field perpendicular to each other. A linear representation of electromagnetic radiation on the basis of their wavelength or frequency is known as electromagnetic spectrum. An electromagnetic spectrum spans on one side to cosmic and X-ray with a very small wavelength and a very high frequency, while on the other side microwaves and radio waves with a very large wavelength or small frequency. Primary radiations that lie within this range include infrared radiation (IR), visible light (V), and UV radiations.
Treatment of Pressure Sores
Published in J G Webster, Prevention of Pressure Sores, 2019
Electromagnetic (em) energy in the form of infrared radiation has been indicated for slow-healing indolent wounds because it can increase vasodilation by its thermal effects (Wadsworth and Chanmugam 1983). Infrared radiation has a wavelength between 770 and 15,000 nm. The infrared rays are generated using luminous or nonluminous generators. Luminous generators are incandescent lamps with tungsten or carbon filaments. The filament is placed in a glass bulb which contains an inert gas or a vacuum. Rays with wavelengths from 392 to 800 nm are emitted as current passes through the filament and produces heat. Nonluminous infrared generators usually consist of a wire wrapped around a cylinder of insulating material. The infrared rays produced by either method are directed by parabola-shaped lamps to create a floodlight or spotlight beam. Infrared radiation is not recommended for infected wounds because the increase in temperature can raise the infective activity.
Infrared Thermal Imagers
Published in Kurt Ammer, Francis Ring, The Thermal Human Body, 2019
The ability to focus a lens system in the same way as with a photographic camera has also simplified the camera system, leading to reduction in size and simpler use (Fig. 4.7) [2]. There are a limited number of materials that can be used to transmit infrared radiation. Few are, however, stable enough for practical use. Germanium is one that is suitable especially for long-wave IR, but is expensive. Gallium arsenide and silicon, zinc sulphide (ZnS) and zinc selenide (ZnSe) are used as less expensive materials and are suitable for the medium-wave IR. To determine the materials that can be optically polished with good performance is a subject of continuing research. Where a lens is used as an objective and exposed to the user, care must be taken to keep it covered by the lens cap when not in use, and avoid any physical contact with the lens surface.
Imaging-based internal body temperature measurements: The journal Temperature toolbox
Published in Temperature, 2020
Juho Raiko, Kalle Koskensalo, Teija Sainio
In 1974, Edrich et al. [100] and Enander et al. [101] suggested that internal body temperatures could be measured by a radiometer measuring millimeter wavelength thermal noise signals. A microwave radiometer is a passive receiver measuring the intensity of thermally generated microwave electromagnetic noise by all substances with a temperature above 0 K. The intensity of the microwave noise signal correlates directly with the absolute temperature of the target tissue [102]. The antenna of the radiometer device is placed on the surface of the body above the target tissue to perform the measurement of the deep temperature (see Figure 8). The microwave radiation received by the antenna is then converted to absolute temperature based on the weighted average of the radiation pattern of the target material [103]. The advantage of microwaves over infrared radiation is the higher tissue penetration of radio waves with high wavelength: while infrared has poor penetration and can be used to measure only the surface temperature, radio waves penetrate several centimeters of subcutaneous tissue and can be used to measure internal tissue temperature. The power P of the radio length radiation of the examined tissue can be described as:
Infrared analyzers for the measurement of breastmilk macronutrient content in the clinical setting
Published in Expert Review of Molecular Diagnostics, 2020
Cristina Borràs-Novell, Ana Herranz Barbero, Victoria Aldecoa-Bilbao, Georgina Feixas Orellana, Carla Balcells Esponera, Erika Sánchez Ortiz, Oscar García-Algar, Isabel Iglesias Platas
Milk analyzers are based on infrared spectroscopic technology that works on the principle of absorbance at wavelengths that are most sensitive to specific chemical bonds in protein (amide), fat (carbonyl and carbon-hydrogen) and carbohydrate (hydroxyl) [27]. The sample is exposed to infrared radiation [37]; the infrared radiation is generally divided into three regions; near (0.7–2.5 µm), mid (2.5–25 µm), and far (25–1000 µm) infrared, named for their relation to the visible spectrum. The amount of energy absorbed at the macronutrients specific wavelengths is proportional to the concentration of the macronutrients (Beer-Lambert Law) [31]. The main characteristics of the five human milk analyzer models included in this review are summarized in Table 1 [27,38–45].
Thermal field formation during wIRA-hyperthermia: temperature measurements in skin and subcutis of piglets as a basis for thermotherapy of superficial tumors and local skin infections caused by thermosensitive microbial pathogens
Published in International Journal of Hyperthermia, 2019
Helmut Piazena, Werner Müller, Wolfgang Pendl, Sereina von Ah, Veronika H. Cap, Petra J. Hug, Xaver Sidler, Gerd Pluschke, Peter Vaupel
Water-filtered infrared-A (wIRA) radiation (780–1400 nm) [1] shows a significantly deeper penetration into skin and subcutaneous tissue compared to unfiltered IR-A radiation and both, the middle (IR-B, 1400–3000 nm) and the long-wavelength (IR-C, 3000 nm–1 mm) infrared radiation [2,3]. This property causes basic differences concerning tissue heating as compared to conventional heat sources used in thermotherapy such as unfiltered IR-A, IR-B, IR-C, heating packs, hot-water baths and heated air/vapor flows reported by various authors. Advantages include (a) significant heat generation by absorption of radiation not only in the uppermost skin layers or at the skin surface, but also in deeper tissues layers [3]; (b) threshold skin surface temperatures for induction of heat pain [4,5] are reached at significantly higher incident irradiances as compared to short-wavelength IR (by a factor of about 2.5) and IR-C (by a factor of about 3.6) [2,6] and (c) significantly smaller temperature decrease within deeper tissue layers as compared to short-wavelength IR or hot packs [7].