LUMENIS Novus Spectra, Руководство оператора

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General Information 77
Novus Spectra
0642-543-01, Rev A, 12/02
tissue turns black, temperatures rise fast because scattering
stops and absorption proceeds rapidly (black absorbs all
visible wavelengths). Charring is the visual signal that the
final phase, tissue ablation, is about to begin.
Phase 5 Carbonization or charring of the tissue surface indicates
high-temperature processes. The surgeon can see the tissue
being vaporized as a plume of gas and smoke. Ablation
temperatures for calcified tissues may exceed 500°C.
Table 3: The effect of temperature increase on tissue
Operators should be aware that laser light is transmitted through transparent
and translucent tissue with relatively little absorption. Particular care should
be exercised so that the laser light is not transmitted through such tissue or
fluids, with attendant thermal damage to more highly pigmented tissue in
underlying or surrounding regions. The wavelength will be transmitted
through water or other clear irrigating solutions, such as Ringer’s, without
absorption.
Analysis of clinical and laboratory experience to date indicates that irradiance
of roughly 100 W/cm
2
to 500 W/cm
2
is required for the adequate
photocoagulation of tissues. Incisional and excisional vaporization (debulking)
occurs with irradiance greater than 1000 W/cm
2
. Irradiance greater than
5,000 W/cm
2
results in rapid incision. (See Table 2).
Phase
Tissue
Temperature
Tissue Effect
Surgeon’s
Observation
1
43-50°C Temperature Increase No visible change
2
50-60°C Protein Denaturation Blanching (whitening)
3
90-100°C Water Evaporates Shrinkage
4
100-150°C Tissue Carbonizes Blackening (Charring)
5
> 175 °C All Vaporize Smokey Plume, Reduction
in volume