Encision EM3 AEM, Руководство пользователя, Страница: 32 / 48

Principles of Operation
5-2 EM3 AEM Monitor User’s Guide
Capacitively coupled currents also have the potential for causing burns. The radio-frequency
energy used in electrosurgery will flow between closely spaced conductors even though there
is no direct connection between them. The active electrode and a metallic cannula are
closely spaced conductors, and they form a capacitor which can conduct radio-frequency
current. Testing has shown that 5% to 40% of the power indicated on the electrosurgical
generator may be delivered from a metallic insulated trocar sheath to the patient’s tissues.
This amount of power is enough to quickly cause a serious burn.
AEM instruments, in conjunction with an AEM Monitor properly connected to the
electrosurgical generator (ESU), continuously monitor and dynamically manage “stray
energy” (insulation failure and capacitive coupling) in zones 2 & 3.
WARNING
AEM shielding does not cover zone 1, which the surgeon should keep in view during
instrument activation.
Protective Shield
Primary Insulation Layer
Active Electrode Element
Outer Insulation
Active Electrode
Bowel
Metal cannula with
insulated outer
surface
Abdominal Wall
Capacitively
Coupled Energy
to Cannula
Zone 1 Zone 2 Zone 3
Electrode Insulation
Failure
Abdominal Wall
Active Electrode
Bowel Cannula
Zone 1 Zone 2 Zone 3