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The first 25 slides, exactly as they appear. The full deck has 95 content slides.
Dermatology
Lasers and Other Energy-Based Technologies – Principles and Skin Interactions
Built from Dermatology, 5th Edition
What’s inside
8 sections · 95 slides
Overview
- Six things this topic covers
How Lasers Work
From Einstein's physics to a beam that can be aimed at a single blood vessel
- What LASER stands for
- A short history of the medical laser
- Four parts every laser needs
- Laser system: how the beam is built and focused
- Gas lasing media
- Liquid lasing media
- Solid lasing media
- Three properties unique to laser light
- Continuous beams, pulses, and Q-switching
Skin Optics
What actually happens to laser light the instant it reaches the skin surface
- Reflection at the skin surface
- Four things a laser beam can do inside skin
- Scattering and absorption
- The four chromophores that matter in skin
- Four skin chromophores at a glance
- Absorption spectra of the four skin chromophores
- The electromagnetic spectrum
- Epidermis versus dermis optics
- Depth of optical penetration by laser wavelength
Heat and Selective Photothermolysis
How a laser destroys one structure in the skin while leaving its neighbours untouched
- Why heat damages tissue
- The heat shock response
- The Arrhenius model of thermal injury
- Thermal relaxation time
- From absorbed light to a selectively damaged target
- Selective photothermolysis: the founding idea
- Target size sets the pulse duration needed
- Pulse durations and targets of selective photothermolysis
- Ultra-short pulses reach ultra-small targets
- Photomechanical effects of a pulsed laser
- Useful laser terms
- What controls the strength of a laser's effect
- Cooling protects the epidermis
- Timing cooling around the pulse
Clinical Applications
Matching wavelength, pulse duration and cooling to a specific skin problem
- The medical laser toolkit
- Lasers in medicine
- Lasers in medicine (continued)
- Lasers in medicine (continued)
- Lasers in medicine (continued)
- Lasers in medicine (continued)
- Lasers in medicine (continued)
- Lasers in medicine (continued)
- Ablative (vaporizing) skin resurfacing
- Resurfacing risks and wound care
- Treating vascular lesions: matching the target
- Port-wine birthmarks and deeper vessels
- Purpura and reducing it with wavelength choice
- Intense pulsed light (IPL) for vessels and pigment
- Melanosomes: the target in pigmented lesions
- How a tattoo is actually removed
- Lasers for pigmented lesions
- Laser hair removal: how it works
- Temporary versus permanent hair loss
- Non-ablative skin rejuvenation
- Fractional photothermolysis: the core idea
- Microscopic thermal injury zone (MTZ) after fractional CO2 laser
- Two forms of fractional photothermolysis
- What fractional lasers are used to treat
- Laser-assisted drug delivery (LADD)
- Laser-induced optical breakdown (plasma)
- Targeting fat and sebaceous glands
- Laser-based imaging for diagnosis
Laser Safety
Eye injury, fire, burns and inhaled plume: the four hazards, and how each is prevented
- Why laser safety cannot be an afterthought
- Principles of laser safety
- Principles of laser safety (continued)
- Principles of laser safety (continued)
- Principles of laser safety (continued)
- Principles of laser safety (continued)
Non-Laser Energy-Based Technologies
Radiofrequency current, focused ultrasound, magnetic pulses, and controlled cooling
- Intense pulsed light: a second look
- Photobiomodulation (low-level light therapy)
- Radiofrequency: how it heats tissue
- Monopolar versus bipolar RF devices
- RF skin tightening and other uses
- High-intensity focused electromagnetic (HIFEM) therapy
- Nano-pulse stimulation (NPS)
- Focused ultrasound: the physics
- Focused ultrasound device design
- Three ways focused ultrasound damages tissue
- Ultrasound in clinical use
- Cryolipolysis: fat reduction by cold
Future Directions
Image-guided surgery, molecular imaging, and mechanical alternatives to fractional lasers
- Image-guided surgery and molecular imaging
- Injectable ice slurry and new cold-based treatments
- Mechanical coring: a non-laser alternative
- Key takeaways
- References
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- Dermatology, 5th Edition (2-Volume Set)