Instructors eBook Test Bank Physical Properties of LED LEDs can produce light that is monochromatic or poly- chromatic and includes visible and infrared light wave- lengths. SLEDs are similar to LEDs but produce higher-intensity light energy. Laser diodes produce light that is monochromatic, coherent, and directional. In contrast, LEDs and SLEDs may be monochromatic but with limited coherence and directionality. 71 Therefore, the classification systems for laser devices do not apply to LEDs and SLEDs. The power output can range from 5 to 40 mW for LEDs and up to 90 mW for SLEDs. Typically, LEDs and SLEDs are arrayed in clusters or pads with as many as 20 or 30 diodes. Because treat- ment time is often longer, the total amount of light en- ergy with clusters of LEDs can far exceed the dosages used during LLLT applications. The amount of light energy provided by LED and SLED light sources can produce superficial heating of the skin. 72 Image Bank PowerPoints 624 pages | 360 illustrations Hardcover | 2022 $110.95 (US) ISBN 13: 978-1-7196-4199-9 Light-Emitting Diodes The reemergence of low-level laser technology and clinical applications in physical therapy in the early 2000s paralleled the development and availability of LED devices, whose proposed benefits are comparable to those of LLLT. Specific FDA clearance for the new LED devices, particularly infrared LEDs, was not re- quired because of previous approvals of infrared lamps used by physical therapists for decades as a superficial heat modality. Infrared heat lamps have been largely replaced by moist heating pads and hot packs because of the increased risk of burns from the heat lamps. Key Point! LEDs are similar to lasers because the light produced by both is monochromatic. How- ever, the light emitted by LEDs has limited coher- ence and directionality. Proposed Physiological Effects of LED Studies have reported that the effects of light on cellular processes are the same for both laser and nonlaser light sources. 73,74 The effects of light on cells appear to be wavelength-dependent, assuming the necessary amount of light energy reaches and is absorbed by biological A Key Point! boxes highlight information important to the effective application of the modalities. Full-color photographs demonstrate the equipment and techniques for each modality.
tissues. 73–75 Numerous in vivo and in vitro animal and human studies have demonstrated that LEDs affect cellular processes similarly to laser. 75–77 The physiological effects of infrared light on biolog- ical tissue are believed to occur primarily by photo- chemical reactions rather than thermal effects. Leonard et al 78 found that infrared light treatments were more effective in improving sensation in patients with pe- ripheral neuropathy than in patients who received placebo pads that emitted a comparable thermal effect. Various researchers reported that infrared LEDs de- creased conduction velocities and evoked potentials in normal nerves, although others found that LEDs had no effect on peripheral nerves or that observed increases in conduction velocity may be due to superficial heat- ing of the skin over the sensory nerve tested. Horwitz et al 79 reported that application of infrared light to the skin for 30 minutes increases plasma nitric oxide (NO). Infrared light releases NO from red blood cells and causes vasodilation and increased circulation in the treated tissues. NO increases vascular perfusion by dilating arterioles, resulting in enhanced tissue oxygena- tion, nutrient delivery, and removal of waste products of metabolism. Human blood lymphocytes irradiated with infrared light had an increased level of ATP in cells. These effects may explain the enhancement of wound healing in patients treated with infrared light. Promotion of circulation with resultant oxygenation in tissues treated with infrared light may stimulate nerve growth in patients with peripheral neuropathy. Clinical Controversy The light produced by laser technology and LED/SLED technology is similar in its characteristics, including a lack of coherence and collimation in nonlaser light. This has led to ongoing discussion about whether various sources of light produce the same clinical effects and proposed benefits. The majority of clinical research on light therapy in physical therapy and reha- bilitation is limited to LLLT. Physical Properties of LED LEDs can produce light that is monochromatic or poly- chromatic and includes visible and infrared light wave- lengths. SLEDs are similar to LEDs but produce higher-intensity light energy. Laser diodes produce light that is monochromatic, coherent, and directional. In contrast, LEDs and SLEDs may be monochromatic but with limited coherence and directionality. 71 Therefore, the classification systems for laser devices do not apply to LEDs and SLEDs. The power output can range from 5 to 40 mW for LEDs and up to 90 mW for SLEDs. Typically, LEDs and SLEDs are arrayed in clusters or pads with as many as 20 or 30 diodes. Because treat- ment time is often longer, the total amount of light en- ergy with clusters of LEDs can far exceed the dosages used during LLLT applications. The amount of light energy provided by LED and SLED light sources can produce superficial heating of the skin. 72 Indications for LED Therapy Several studies on the effects of LED applications to open skin wounds reported generally favorable out- comes, including the treatment of chronic venous ulcers, Key Point! LEDs are similar to lasers because the light produced by both is monochromatic. How- ever, the light emitted by LEDs has limited coher- ence and directionality. Clinical Controversy boxes offer different opinions on the appropriate use of modalities.
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PHYSICAL AGENTS
Michlovitz’s Modalities for Therapeutic Intervention, 7th Edition A volume in the Contemporary Perspectives in Rehabilitation Series Curated by Steven L. Wolf, PhD, PT, FAPTA James W. Bellew, PT, EdD, MS Thomas P. Nolan Jr., PT, DPT, MS, OCS Effectively integrate modalities into plans of care Implement a current, evidence-based approach to the selection, application, and uses of therapeutic modalities as an essential tool for functionally based rehabilitation and as a complement to other types of interventions in a patient-centered model of care. Students will develop in-depth understanding of the science behind each modality, its advantages and limitations, its appropriateness for specific conditions, and its implementation. The most current information on the science and practice of therapeutic interventions A more step-by-step approach to the application of the agents “ For Whom and When” boxes and “Complementary Role” sections Case studies with clinical decision components that feature rationales for selecting and applying each therapeutic modality as well as new, open-ended questions “Clinical Controversy” boxes offering different opinions on the appropriate use of modalities Suggested lab activities to promote discussion and hands-on practice Light-Emitting Diodes The reemergence of low-level laser technology and clinical applications in physical therapy in the early 2000s paralleled the development and availability of LED devices, whose proposed benefits are comparable to those of LLLT. Specific FDA clearance for the new LED devices, particularly infrared LEDs, was not re- quired because of previous approvals of infrared lamps used by physical therapists for decades as a superficial heat modality. Infrared heat lamps have been largely replaced by moist heating pads and hot packs because of the increased risk of burns from the heat lamps. 180 Section II ■ Types of Modalities
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Proposed Physiological Effects of LED Studies have reported that the effects of light on cellular
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