27/04/04 ©
Söring
Users manual RF-units
1
not valid for MBC600
-10-
active electrode
horny layer
papilliary body
subcutaneous fatty tissue
musculature with connective
tissue
vessel
bone
Fig 3.2
Schematic representation of a melt-cut: Depending on the value of resistance of the
different effected tissue the coagulation seam (the heat damage) is more or less
widespread; broader at the horny layer than in the papillary body or the subcutis, even
wider in the fatty tissue. In the musculature the heating effect melts deeper into the gaps of
the connective tissue. Within a cut vessel the blood retracts and the intima is damaged
from the different wall layers over a large area. In bones, the heating effect spreads along
both sides of the periosteum and spreads only slowly deeper below the tip of the electrode.
If, however, the heat developed is extended to a larger area due to a larger contact surface
between active electrode and tissue, boiling of the tissue fluids occurs together with widespread
albumin coagulation. Depending on the used current intensity either depth coagulation (see Fig.
3.3) or a surface coagulation (see Fig. 3.4) with eschar generation is achieved. Due to bad
thermal conductivity of eschar, heat transfer, especially into the depth, is prevented by eschar
formation.
