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Ch6 Lasers
ST Lasers
Question | Answer |
---|---|
Argon Laser | Gas; Blue/Green Light; visible laser; travels through clear fluids; treats diabetic retinopathy; can be used through a cystoscope to vaporize bladder tumors |
Gas Lasers | This active medium is energized by electricity to produce the laser light. Examples include CARBON DIOXIDE, HELIUM-NEON, KRYPTON, ARGON, AND EXCIMER. |
Solid Lasers | An energy-producing element on a rod is energized by flash lamps to produce the laser light. Examples include RUBY and Nd:YAG. |
Liquid | An organic dye is energized by a laser beam to produce the laser light in various wavelengths. |
Semiconductor crystals | Laser energy is delivered directly to tissue through a filter or slit-lamp microscope. |
NeoDymum: Yttrium-Alminum-Garnett (Nd:YAG) Laser | invisible laser beam; requiring a helium neon laser aiming beam; absorbed by darker pigmented tissue; can be transmitted through clear fluids; often used to vaporize bladder tumors |
Holimium: Yag Laser | Discharges a pulse beam; transmitted through clear fluids, used during orthopedic/arthroscopic, atherectomy dentistry, radial keratoplasty |
Krypton Laser | Gas; an electrical current activates the krypton medium to create the laser energy; wavelengths vary; colors include green, yellow (most often) RED. used to destroy tissue on eye retina. |
Excimer Laser | Gas; ultra violet in color; absorbed by protein with minimal spread; halogens as the active medium; Destroys plaque in arteries; reshapes the cornea |
Excimer Laser | Excellent presision that can be achieved in cutting & coagulating tissue; gases are fatal possibility of harmful effect to exposure to ultra violet radiation |
Lasers in Endoscopy | used for gastrointestinal endoscopy, beam penetrates deeply for better coagulation & destructs tumor masses; used to treat angioplasisas within thin walls of the intestines |
CO2 & Nd:YAG Lasers are instruments of choice for laser bronchoscopy | |
urethral strictures vaporize bladder tumors framents calculi in the ureter | Nd:YAG |
High humiidity often results in static charge leakage | low humidity results in the formation of sparks |
Insulators | materials that inhibit the flow of electrons; poor conductors; prevent leakage of electrons |
Matter | anything that has mass and occupies space |
Atoms | composed of small particles: protons, neutrons, electrons |
Atoms center | the neucleus & contains protons |
Electrons | revolve around the nucleaus in paths called shells or orbits |
Outer electrons | free electrons |
atoms, elecctrons, & matter | based on Bohr's theory |
Conductors | materials that allow the flow of free electrons |
Ex. of Conductors | silver, copper, aluminum, zinc, brass, iron, saltwater, carbon, & some acids; Copper is most commonly used |
sound wave | produced by vibrating objects that set surrounding air molecules into vibrating motions |
Molecules | groups of atoms jooined by chemical bonds |
physics | work is defined as a force acting on an object to cause a dislacement |
also known as the law of conservation of momentum | Newton's 3rd law |
PET | medical imaging technique that reveals dynamic activities within the body, such as blood flow and glucose uptake in tissues |
The x-ray machine | utilizes electromagnetic radiation to view internal structures |
Bipolar electrosurgery is used just for coagulating | |
The active electrode delivers the electric current to | the surgical site through the tissue |
Surgical lamps | are resistive energy loads |
Load | device that transforms the electrical energy into a useful function |
Ohm's law | scientific law that pertains to electricity |
Current | measured in amps |
Collimated | waves that are parallel to eachother |
LASER | Light Amplification by the Stimulated Emission of Radiation |
cO2: most frequently used; invisible beam; located in the middle of infrared region in electromagnetic spectrum | helium-neon laser is red; no effect on surrounding tissues; precise cutting & coagulating because of energy absorbtion by cellular water content; absorption not dependant on tissue color or consistancy; does not scatter |
cO2: beam is enlarged for coagulating tissue penetration depth is controlled bt power density & fluence; absorbed by water(not transmitted thru clear fluids) | backstop needed; beam will go thru deeper; both beams delivered thru an articulated arm that is a hollow tube; beams are reflected off mirrors down tube |