Laser Therapy & Physics Principles PDF

PT-PAP 101 THERAPEUTIC LASER December 25, 2024 www.gmu.ac.ae COLLEGE OF HEALTH SEIENCES Learning Objectives: On completion of this lesson, the student will be able to: Explain the working principle of LASER; Apply the principles o...

PT-PAP 101 THERAPEUTIC LASER December 25, 2024 www.gmu.ac.ae COLLEGE OF HEALTH SEIENCES Learning Objectives: On completion of this lesson, the student will be able to: Explain the working principle of LASER; Apply the principles of LASER in therapeutic modalities for treating clinical conditions  LASER Light Amplification by Stimulated Emission of Radiation In the therapeutic uses of laser, helium/neon mixture (He-Ne) in the 632.8 nm- Near Infra-red bands of the EM spectrumis utilized by physical therapists. It emits no heat, sound, or vibration. It is also called photobiology or biostimulation.  Physics applied to LASER Follows the Laws of Light Travels in straight lines at a constant velocity in space. It can be transmitted, reflected, refracted and absorbed. It can be placed within the electromagnetic spectrum according to its wavelength/frequency The power levels of light are greatly amplified by the emission of radiation of specific substances, such as: helium neon, cobalt and carbon dioxide.  Physical characteristics of laser Monochromatic - single wavelength, single color Coherent - travels in straight line Collimation - concentrates its beam in a defined location/spot Production of laser In lasers, photons are interacted in three ways with the atoms: Absorption of radiation Spontaneous emission Stimulated emission Production- Stimulated Emission Stimulated emission is the process by which incident photon interacts with the excited electron and forces it to return to the ground state. LASER PRODUCTION Lasing medium : material capable of producing LASER. Eg. Helium-neon or semiconductor like gallium arsenide. Resonating chamber – It contains lasing medium which is surrounded by two parallel mirror at either end. One of the mirror has 100% reflection while other had slightly less reflectance. Energy source -A flash gun is used to excite the electron of the lasing medium. The source of flashgun is usually current electricity High Level Laser & Low-Level Laser Low- Cold- Energy – 1-500 mW High- Thermal Energy – 3000-10000 mW  Therapeutic Laser Low level laser is believed to affect the function of connective tissue cells (fibroblast), accelerate connective tissue repair and act as an anti-inflammatory agent. Lasers with different wavelengths, varying from 632 to 904 nm, are used in the treatment of musculoskeletal disorders. Wavelengths between 660 nm and 905 nm have the ability to penetrate skin, and soft/hard tissues  Therapeutic Laser The photons are absorbed by mitochondrial chromophores in skin cells. Consequently electron transport, adenosine triphosphate (ATP) nitric oxide release, blood flow, reactive oxygen species increase and diverse signaling pathways get activated. Stem cells can be activated allowing increased tissue repair and hea Therapeutic Laser NIR-Near-infrared light therapy Physiological Effect of LASER Wound Healing- Stimulation of Intracellular structure and function Analgesic effect- Cold Laser  Wound healing: Research has proven that laser plays an important role in acceleration of wound healing through stimulation of the intracellular structures and functions. This may be attributed to its effect on mitochondria, responsible for the production of DNA, RNA and other metabolism-related substances. Analgesic effect: In pain control, the cold laser beam is directed at the acupuncture points. These points in addition to the nerve roots form the trigger points for pain relief. Reduces Swelling Physiological effect Queries  Reference Avci P, Gupta A, Sadasivam M, Vecchio D, Pam Z, Pam N, Hamblin MR. Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring. Semin Cutan Med Surg. 2013 Mar;32(1):41-52. PMID: 24049929; PMCID: PMC4126803. Lyu K, Liu X, Jiang L, Chen Y, Lu J, Zhu B, Liu X, Li Y, Wang D, Li S. The Functions and Mechanisms of Low- Level Laser Therapy in Tendon Repair (Review). Front Physiol. 2022 Feb 15;13:808374. doi: 10.3389/fphys.2022.808374. PMID: 35242050; PMCID: PMC8886125. Bjordal, J.M., Lopes-Martins, R.A.B. and Frigo, L. (2015). Low level laser therapy – mechanism of action. In Lasers in Dentistry (eds P.M. de Freitas and A. Simões).