Therapeutic Laser Overview

Therapeutic Laser Overview

• Therapeutic laser, also known as low-level laser therapy (LLLT), uses lasers with specific wavelengths to treat various conditions.
• The therapeutic effects of lasers are believed to be related to the interaction of photons with the cells and tissues.
• Different types of lasers are categorized as either low-level or high-level based on their power output.
• Low-level lasers have power ratings of 1-500 mW.
• High-level lasers have power ratings of 3000-10000 mW.

Laser Principles

• Lasers use a process called stimulated emission. This process amplifies light by stimulating atoms to emit photons of the same wavelength and phase.
• The lasing medium is the material used within the laser to produce laser light.
• The lasing chamber contains a medium, surrounded by mirrors. One mirror has 100% reflectivity while the other mirror has slightly less reflectivity.
• The energy source, often an electrical discharge or flash gun, is used to excite electrons in the lasing medium to stimulate the emission of photons.
• Lasers follow the laws of light. They travel in straight lines at a constant velocity, and can be transmitted, reflected, refracted and absorbed.
• Lasers are classified by their wavelengths; wavelengths are measured in nanometers (nm).

Laser Characteristics

• Monochromatic: Lasers emit light at a single wavelength, creating a single color.
• Coherent: The light waves emitted by a laser are highly coherent, meaning that they are in phase with one another, traveling in a straight line.
• Collimated: The laser beam is highly parallel, and concentrates its light into a defined area. Normal light diverges.

Laser Production

• Photons in lasers interact with atoms in three ways: absorption, spontaneous emission, and stimulated emission.
• Absorption: When a photon interacts with an atom, it can transfer energy to the atom transferring it to a higher energy state.
• Spontaneous emission: When an atom is in an excited energy state, it can spontaneously return to the ground state, emitting a photon.
• Stimulated emission: A photon can interact with an excited atom, causing it to return to the ground state and emit a second photon with the same energy, wavelength, and phase as the first photon.

Therapeutic Mechanisms (Low-Level Laser Therapy)

• Low-level lasers are believed to affect the function of connective tissue cells (fibroblasts), accelerate connective tissue repair, and act as anti-inflammatory agents.
• Lasers used in low level laser therapy have varying wavelengths that can penetrate through soft and hard tissues, including skin. Wavelengths in the range of 632-904 nm are most commonly used. 660nm - 905nm is ideal for penetration.
• Photons from low level lasers are absorbed by mitochondrial chromophores in skin cells. This absorption process can trigger changes in cellular activities, such as stimulating electron transport, releasing adenosine triphosphate (ATP), nitric oxide, and boosting blood flow and reactive oxygen species.
• These combined effects can stimulate stem cells and encourage increased tissue repair and healing.

Physiological Effects

• Wound Healing: Stimulation of intracellular structures and functions.
• Analgesic effect: Cold laser can reduce pain (analgesic) by directly affecting pain receptors or trigger points.
• Reduced Swelling

Output of Low And High Level Lasers

• Low power cold lasers have output between 1 and 500 mW.
• High power thermal lasers have an output between 3000 and 10,000mW.

Explore the fundamentals of therapeutic laser technology, also known as low-level laser therapy (LLLT). Understand the principles behind laser operation, including stimulated emission and the classification of lasers based on power output. This quiz covers various aspects of laser interaction with cells and tissues for therapeutic applications.