Biomedical Engineering Reference
In-Depth Information
and the high level to 9% coverage. It utilizes a disposable treat-
ment tip per treatment. It can be used in all skin types, although
we have experience with other 1440-nm devices and fi nd that
the risk of PIH is higher with 1440-nm than with 1540- to
1500-nm devices. It is marketed as a preventive laser treatment
and provides a superfi cial treatment with minimal down time.
It is marketed to medical spas primarily.
into interstitial spaces of the skin. With less water to absorb, the
scattering of laser light is reduced which enables increased
absorption of light by deeper targets. The compression into the
skin not only enhances beam penetration, it enhances the skin
cooling effect due to loss in heating in the epidermis. Better
cooling means decreased epidermal temperature and injury.
Clinically, this translates into fewer side effects, less downtime,
and a more comfortable treatment. The XF optic provides
higher coverage per pulse, compared with the original optics,
allowing faster treatments times, similar to 1440 nm but with
the added benefi t of increased depth due to the increased pen-
etration of the 1540-nm wavelength.
These laser treatments are customized by controlling the
microbeam energy, the amount of overlap between pulses and
the number of passes. The pulse energy is delivered in milli-
joules per microbeam (mJ/mb) and it controls the depth of
penetration or the depth of the MTZ. Energies should be
adjusted for the skin condition being treated. Lower energies
are utilized for more superfi cial conditions and higher ener-
gies, which penetrate deeper, are used for deeper indications.
The percentage of skin treated or covered by MTZs during one
treatment session is determined by the amount of overlapping
the palomar family of nafl
The Palomar family of NAFLs (Palomar Medical Technologies,
Inc.) includes a 1540-nm erbium: glass laser, a 1440-nm
Nd:YAG laser, and a 1410-nm diode home use laser. With the
exception of the 1410-nm diode home use laser, these wave-
lengths are delivered through a variety of microlenses, which
can be used in three different laser/pulsed light platforms: the
StarLux, Artisan, and Icon. These devices, like the Cynosure
Affi rm laser, are based on the stamping mode of delivering
fractional energy with the microdots of energy coming
through microlens arrays. The latest generation of Palomar's
NAFL is available through the Icon™ Aesthetic system plat-
form which has four unique 1540-nm handpiece microlenses;
the original 10-mm and 15-mm microlenses, the 15-mm XF
Microlens, and the XD Microlens. See Figure 8.7 that illustrates
the ICON 1540-nm interface. Furthermore, the new XD Micro-
lens can be used on any of the previous generation 1440-nm and
1540-nm fractional handpieces with the appropriate software
and factory calibration.
The original fractional microlenses are composed of a
microlens array that delivers a lattice of optical microbeams
that create microdenatured columns in the skin. The microlens
is responsible for taking a single beam of laser energy and sepa-
rating it out into smaller lasers beams at a predetermined pitch.
See Figure 8.8A,B for photos of the original microlens. The XD
Microlens is a chilled 12
12 mm
2
sapphire contact window
that is composed of 49 microcompression pins each coaligned
with a microbeam. Figure 8.9 depicts the XD microlens tip,
which allows for much deeper (XD = extra deep) penetration
of energy by compression water from the upper layers of der-
mis. This new microlens is used with manual compression into
the skin to achieve deeper penetration of laser energy into the
dermis. A footprint of the XD is seen after 30 seconds of man-
ual pressure (Fig. 8.10). The act of compression displaces water
×
Figure 8.7
Treatment screen for 1540-nm fractional. Here each pulse is 15 ms
and each thermal zone is 50 mJ/cm
2
. Coverage is determined by percent over-
lap of each stamp.
(
A
)
(
B
)
Figure 8.8
(
A
) Microlens array for stamped 1540-nm nonablative fractional laser and (
B
) 15-mm handpiece lens array.
