Chapter 60 : Laser Surgery Flashcards
LASER is an acronym for __________________________
Light Amplification by the Stimulated Emission of Radiation
Who postulated the theoretic foundation of laser action, stimulated emission of radiation, in 1917
Albert Einstein
Excitation that comes from the electron interacting with light (a photon) is termed ______________________________
Absorption
This term refers to the waves of light that oscillate in phase over a given time
Temporal Coherence
This means that the photons are equal and parallel across the wave front
Spatial Coherence
After the laser energy exits the optical cavity through the partially transmissive mirror, the radiant energy typically passes through a lens that focuses the laser beam to a very small diameter, or spot size, that ranges from
0.1 to 2 mm
With most surgical lasers, the physician can control 3 variables
- Power, 2. Spot size, 3. exposure time
the least useful variable and may be kept constant with widely varying effects
Power
________ is the most important operating parameter of a surgical laser at a given wavelength
Irradiance
refers to the distribution of energy across the focal spot and determines the shape of the laser’s spot
Transverse Elecromagnetic Mode (TEM)
The power density of the beam follows a _________ distribution: the greatest amount of energy is at the center of the beam and the amount of energy diminishes progressively toward the periphery
Gaussian
The smallest beam diameter and highest power concentration occur at the focal plane, where much of the precise cutting and vaporization is carried out
TRUE
________ refers to the amount of time (measured in seconds) that a laser beam irradi- ates a unit area of tissue at a constant irradiance
FLUENCE
When the target absorbs a specific amount of radiant energy to increase its temperature to between ___° C and ___° C, protein denaturation occurs
60-65 deg C
The minimal operative trauma, combined with the vascular seal, probably accounts for the absence of postoperative edema that is char- acteristic of laser wounds.
TRUE
According to the study of Buell and Schuller, they compared the rate of tissue repair after CO2 laser and scalpel incisions on hogs. In this study, the tensile strength of the laser incisions was _______ compared to that of similar scalpel incisions during the first 3 weeks after surgery.
Less than
This kind of laser produce blue-green light in the visible range of the electromagnetic spectrum, with primary wavelengths of 0.488 and 0.514 μm
Argon
As part of eye protection for the OR staff, it is important to note that Laser radiation in the ultraviolet (<0.4 μm) or in the
infrared (>1.4 μm) range of the spectrum produces effects pri-
marily which part of the eye?
Cornea
How many suction setups should be available for all laser
cases in the upper aerodigestive tract
Two
Mixtures of helium, nitrogen, or air plus oxygen are commonly used to maintain the forced inspiratory oxygen less than ____ to ensure that the patient is adequately oxygenated.
40%
