Laser Treatment Parameters & Dosage Flashcards
7 cards from real CLT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Laser Treatment Parameters & Dosage flashcards as text
Which tissue characteristic most significantly affects the depth of laser penetration in biological tissue?
Answer: Absorption and scattering coefficients of the tissue
The absorption and scattering coefficients of tissue at a given wavelength determine how deeply photons can penetrate before being absorbed or redirected.
For a Q-switched laser used in tattoo removal, the extremely short pulse duration (nanoseconds) is intended to:
Answer: Create a photoacoustic effect that shatters pigment particles
Q-switched lasers produce nanosecond pulses that generate rapid pressure waves (photoacoustic effect), mechanically fragmenting tattoo pigment particles without excessive thermal damage.
Which parameter directly determines the maximum temperature rise achievable in a target tissue during laser irradiation?
Answer: Irradiance (W/cm²) and pulse duration together
Temperature rise in tissue is governed by both the rate of energy delivery (irradiance) and how long that energy is applied (pulse duration), which together determine total heat deposited.
A therapist is treating superficial capillaries with a 532 nm KTP laser. Why is this wavelength chosen over 1064 nm?
Answer: 532 nm is more strongly absorbed by oxyhemoglobin
Oxyhemoglobin has strong absorption peaks around 532 nm (and 577–585 nm), making KTP lasers highly effective for targeting superficial vascular lesions.
If a therapist increases the laser power from 1 W to 4 W while keeping spot size and exposure time constant, the fluence will:
Answer: Quadruple
Fluence = (Power × Time) / Area; quadrupling power with the same time and area quadruples the fluence delivered.
In laser therapy treatment planning, 'fractionation' refers to:
Answer: Treating only a fraction of the skin surface per pass to allow recovery of intervening tissue
Fractionated laser treatment creates columns of injury separated by untreated zones, allowing rapid healing from surrounding intact tissue.
The Minimum Erythema Dose (MED) concept is most closely associated with which laser therapy modality?
Answer: Photobiomodulation dosimetry for UV-free phototherapy
MED is a dosimetry concept from phototherapy that identifies the minimum dose producing visible erythema, used as a reference point for calibrating photobiomodulation and phototherapy doses.