Instruct: Given a question, retrieve documents that can help answer the question.
Query: How is infrared light used in therapy?
Since then a large array of treatments using controlled light have been developed. Though the popular consumer understanding of "light therapy" is associated with treating seasonal affective disorder, circadian rhythm disorders and skin conditions like psoriasis, other applications include the use of low level laser, red light, near-infrared and ultraviolet lights for pain management, hair growth, skin treatments, and accelerated wound healing.
The infrared spectrum of a sample is recorded by passing a beam of infrared light through the sample. When the frequency of the IR is the same as the vibrational frequency of a bond or collection of bonds, absorption occurs. Examination of the transmitted light reveals how much energy was absorbed at each frequency (or wavelength). This measurement can be achieved by scanning the wavelength range using a monochromator. Alternatively, the entire wavelength range is measured using a Fourier transform instrument and then a transmittance or absorbance spectrum is generated using a dedicated procedure.
Infrared cut-off filters are designed to block or reflect infrared wavelengths but pass visible light. Mid-infrared filters are often used as heat-absorbing filters in devices with bright incandescent light bulbs (such as slide and overhead projectors) to prevent unwanted heating due to infrared radiation. There are also filters which are used in solid state video cameras to block IR due to the high sensitivity of many camera sensors to unwanted near-infrared light.
Light therapy is a treatment method that involves delivering certain specific wavelengths of light to an area of skin affected by acne. Both regular and laser light have been used. When regular light is used immediately following the application of a sensitizing substance to the skin such as aminolevulinic acid or methyl aminolevulinate, the treatment is referred to as photodynamic therapy (PDT). PDT has the most supporting evidence of all light therapies. Many different types of nonablative lasers (i.e., lasers that do not vaporize the top layer of the skin but rather induce a physiologic response in the skin from the light) have been used to treat acne, including those that use infrared wavelengths of light. Ablative lasers (such as CO and fractional types) have also been used to treat active acne and its scars. When ablative lasers are used, the treatment is often referred to as laser resurfacing because, as mentioned previously, the entire upper layers of the skin are vaporized. Ablative lasers are associated with higher rates of adverse effects compared with nonablative lasers, with examples being postinflammatory hyperpigmentation, persistent facial redness, and persistent pain. Physiologically, certain wavelengths of light, used with or without accompanying topical chemicals, are thought to kill bacteria and decrease the size and activity of the glands that produce sebum. As of 2012, evidence for various light therapies was insufficient to recommend them for routine use. Disadvantages of light therapy can include its cost, the need for multiple visits, time required to complete the procedure(s), and pain associated with some of the treatment modalities. Various light therapies appear to provide a short-term benefit, but data for long-term outcomes, and for outcomes in those with severe acne, are sparse; it may have a role for individuals whose acne has been resistant to topical medications. A 2016 meta-analysis was unable to conclude whether light therapies were more beneficial than placebo or no treatment, nor how long potential benefits lasted. Typical side effects include skin peeling, temporary reddening of the skin, swelling, and postinflammatory hyperpigmentation.
Photothermal therapy (PTT) refers to efforts to use electromagnetic radiation (most often in infrared wavelengths) for the treatment of various medical conditions, including cancer. This approach is an extension of photodynamic therapy, in which a photosensitizer is excited with specific band light. This activation brings the sensitizer to an excited state where it then releases vibrational energy (heat), which is what kills the targeted cells.
An infrared gas analyzer measures trace gases by determining the absorption of an emitted infrared light source through a certain air sample. Trace gases found in the Earth's atmosphere get excited under specific wavelengths found in the infrared range. The concept behind the technology can be understood as testing how much of the light is absorbed by the air. Different molecules in the air absorb different frequencies of light. Air with lots of a certain gas will absorb more of a certain frequency, allowing the sensor to report a high concentration of the corresponding molecule.
Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with high light output.
A study of patients with rheumatoid arthritis and ankylosing spondylitis showed a reduction in pain, stiffness and fatigue during infrared therapy, but since results from the study did not reach statistical significance there is no clear or certain relationship between reducing symptoms and using infrared therapy.
In infrared photography, the film or image sensor used is sensitive to infrared light. The part of the spectrum used is referred to as near-infrared to distinguish it from far-infrared, which is the domain of thermal imaging. Wavelengths used for photography range from about 700 nm to about 900 nm. Film is usually sensitive to visible light too, so an infrared-passing filter is used; this lets infrared (IR) light pass through to the camera, but blocks all or most of the visible light spectrum (the filter thus looks black or deep red). ("Infrared filter" may refer either to this type of filter or to one that blocks infrared but passes other wavelengths.)
Infrared and optical astronomy are often practiced using the same telescopes, as the same mirrors or lenses are usually effective over a wavelength range that includes both visible and infrared light. Both fields also use solid state detectors, though the specific type of solid state detectors used are different. Infrared light is absorbed at many wavelengths by water vapor in the Earth's atmosphere, so most infrared telescopes are at high elevations in dry places, above as much of the atmosphere as possible. There are also infrared observatories in space, including the Spitzer Space Telescope and the Herschel Space Observatory.
A thermographic camera (also called an infrared camera or thermal imaging camera or infrared thermography) is a device that forms a heat zone image using infrared radiation, similar to a common camera that forms an image using visible light. Instead of the 400–700 nanometre range of the visible light camera, infrared cameras operate in wavelengths as long as 14,000 nm (14 µm). Their use is called thermography.
The high scatter-based attenuation involved is generally dealt with by using intense, often pulsed or intensity modulated, light sources, and highly sensitive light sensors, and the use of infrared light at frequencies where body tissues are most transmissive. Soft tissues are highly scattering but weakly absorbing in the near-infrared and red parts of the spectrum, so that this is the wavelength range usually used.
A variant of optical tomography uses optical time-of-flight sampling as an attempt to distinguish transmitted light from scattered light. This concept has been used in several academic and commercial systems for breast cancer imaging and cerebral measurement. The key to separation of absorption from scatter is the use of either time-resolved or frequency domain data which is then matched with a diffusion theory based estimate of how the light propagated through the tissue. The measurement of time of flight or frequency domain phase shift is essential to allow separation of absorption from scatter with reasonable accuracy.
Variations of LLLT have gone by a variety of alternate names including low-power laser therapy (LPLT), soft laser therapy, low-intensity laser therapy, low-energy laser therapy, cold laser therapy, bio-stimulation laser therapy, photobiomodulation, photo-biotherapy, therapeutic laser, and monochromatic infrared light energy (MIRE) therapy. When LLLT is administered to so-called "acupuncture points", the procedure may be called laser acupuncture. When applied to the head, LLLT may be known as transcranial photobiomodulation, transcranial near-infrared laser therapy (NILT)
, or transcranial low level light therapy.
Physiotherapy is a treatment that exposes the patient to ultra-violet and infrared lights. Some of these treatments included ultra-violet light, infrared light, electric bake, and diathermy. In 1937 the Ypsilanti State Hospital was introduced to several different shock therapies, including electric shock.
IR radiation is more useful than the visible radiation for heating our body, because we absorb most of it, compared to a strong reflection of visible light. Penetration depth of infrared radiation in our skin is dependent of wavelength. IR-A is the most penetrating, and reaches some millimeters, IR-B penetrates into the dermis (about 1 mm), and IR-C is mostly absorbed in the external layer of the epidermis (stratum corneum). For this reason the infrared lamps used for therapeutic purposes produce mainly IR-A radiation.
According to the American Cancer Society, there is some evidence that ultraviolet light therapy may be effective in helping treat certain kinds of skin cancer, and ultraviolet blood irradiation therapy is established for this application. However, alternative uses of light for cancer treatment– light box therapy and colored light therapy– are not supported by evidence.[11] Photodynamic therapy (often with red light) is used to treat certain superficial non-melanoma skin cancers.[12]
Infrared homing is a passive weapon guidance system which uses the infrared (IR) light emission from a target to track and follow it. Missiles which use infrared seeking are often referred to as "heat-seekers", since infrared is radiated strongly by hot bodies. Many objects such as people, vehicle engines and aircraft generate and emit heat, and as such, are especially visible in the infrared wavelengths of light compared to objects in the background.
"Infrared therapy" uses infrared heaters to emit infrared light experienced as radiant heat which is absorbed by the surface of the skin. Saunas heat the body primarily by conduction and convection from the heated air and by radiation of the heated surfaces in the sauna room. Because of this, infrared therapy is not considered a sauna by Finnish sauna societies. Nevertheless, "Infrared Sauna" and "Infrared Therapy" are respectively a methodology and a terminology in the application of the infrared electromagnetic field spectrum to the human body. There are claims of detoxification which lack scientific evidence. There are at least 48 scientific or medical articles on "Infrared Sauna", 327 on "Far Infrared Therapy" and over twenty one thousand on "Infrared Therapy" some of which investigate health benefits, such as prophylactic physiotherapeutic treatment schemes, appetite loss and depression, cardio vascular system improvements, and Photothermal Therapy.
Absorption of light and energy transfer (or conversion) involves colored molecules that can transfer electromagnetic energy, commonly in the form of a laser light source, to other molecules in another form of energy, such as thermal or electrical. These laser addressable colorants, also called near-infrared absorbers, are used in thermal energy conversion, photosensitisation of chemical reactions and the selective absorption of light. Applications areas include optical data storage, as organic photoconductors, as sensitisers in photomedicine, such as photodynamic therapy and photothermal therapy in the treatment of cancer, in photodiagnosis and phototheranostics, and in the photoinactivation of microbes, blood and insects. The absorption of natural sunlight solar energy by chromic materials/chromophores is exploited in solar cells for the production of electrical energy via solar cells, using both inmorganic inorganic photovoltaics and organic materials organic photovoltaics and dye sensitized solar cells (DSSCs), and also in the production of useful chemicals via artificial photosynthesis. A developing area is the conversion of light into kinetic energy, often described under the generic term of lightdriven/molecular machines.
Infrared lamps are electrical devices which emit infrared radiation. Infrared lamps are commonly used in radiant heating for industrial processes and building heating. Infrared LEDs are used for communication over optical fibers and in remote control devices. Infrared lamps are also used for some night vision devices where visible light would be objectionable. Infrared lamp sources are used in certain scientific and industrial instrument for chemical analysis of liquids and gases; for example, the pollutant sulfur dioxide in air can be measured using its infrared absorption characteristics.
Nonpharmacological treatments involve different interventions, starting with sleep hygiene, which includes sleep promoting activities such as maintaining a regular and strict sleep schedule and avoiding heavy meals before bedtime in order to restore the natural sleep-wake cycle. Further treatments options are phototherapy and infrared light therapy, which both, aim to treat circadian rhythm disorders such as delayed sleep phase disorder. Especially in patients with hypersomnia, bright light therapy in the morning has been proven to be effective. A prolongation of slow-wave sleep increases glymphatic clearance of metabolic waste products, which can lead to improvements of sleep disorders. Furthermore, studies showed ameliorated sleep pattern due to acupuncture of patients with TBI. Sleep apnea due to TBI can be treated through positive airway pressure, which helps with the development of a regular breathing pattern during sleep and prevents waking up. Cognitive behavioral therapy for insomnia also have been shown to effectively improve sleep in TBI patients. It aims to improve sleep habits and behaviors by identifying and changing the thoughts and the behaviors that affect the ability of a person to sleep or sleep well. The improvement of the quality of sleep and the decrease of depressive severity is associated with he use of near-infrared light for intracellular healing.
Infrared tracking, also known as infrared homing, refers to a passive missile guidance system, which uses the emission from a target of electromagnetic radiation in the infrared part of the spectrum to track it. Missiles that use infrared seeking are often referred to as "heat-seekers" since infrared (IR) is just below the visible spectrum of light in frequency and is radiated strongly by hot bodies. Many objects such as people, vehicle engines, and aircraft generate and retain heat, and as such, are especially visible in the infrared wavelengths of light compared to objects in the background.[27]
Fayer’s contributions are a play with two acts. In the first act, approximately 1974 through 1993, Fayer’s ultrafast nonlinear experiments were conducted using visible or ultraviolet light. These were the colors that were available with the laser technology of the time. In the early 1990s, Fayer realized that a great leap could be taken if the experiments could be extended to the infrared regions of the optical spectrum. Infrared light acts on molecular vibrations, which are the motions of the atoms that make up molecules. By using infrared light, it is possible to more directly interrogate the structural dynamics of molecular systems than with the use of visible or ultraviolet light. However, a source of ultrashort infrared light pulses was necessary, so Fayer got together with Stanford physicists to use a physics experiment, the free electron laser, and turn it to the study of molecular process using ultrafast infrared nonlinear experiments. These first experiments using the free electron laser, which was two football fields long and took a crew to run, set off an explosion of interest in infrared nonlinear methods. In less than ten years, it became possible to perform the experiments using lasers that could be housed in a normal laboratory and did not require a free electron laser. Fayer contributed substantially to the equipment side, but his main creative impact was exploiting the new ultrafast infrared methods and technology for a wide variety of fundamentally important molecular problems. These methods have evolved into what are now called ultrafast multi-dimensional infrared spectroscopy. The methods that Fayer popularized are now spread throughout the world.
Infrared is used in night vision equipment when there is insufficient visible light to see.[23] Night vision devices operate through a process involving the conversion of ambient light photons into electrons that are then amplified by a chemical and electrical process and then converted back into visible light.[23] Infrared light sources can be used to augment the available ambient light for conversion by night vision devices, increasing in-the-dark visibility without actually using a visible light source.[23]
There are mainly three methods to melt the solder: hot air, infrared light, and steam-phasing. The infrared light technology works with a focused infrared light beam onto a specific integrated circuit and is used for small chips. The hot air and steam methods cannot focus as much as the infrared technique.