User's Manual

M2540-92000-01 A M2540 Ultrasound System Field Service Manual Page 37
Safety: Electrosurgical Units
Electrosur-
gical Units
Electrosurgical units (ESUs) and other devices intentionally introduce radio frequency
electromagnetic fields or currents into patients. Because imaging ultrasound frequencies are also
in the radio frequency range, ultrasound transducer circuits are susceptible to radio frequency
interference. While an ESU is in use, the noise generated severely interferes with the
black-and-white image and completely obliterates the color image.