Question

What is range of RF signals generated by Electrosurgery machine?

(a) 0 to 0.4 MHz

(b) 0.4 to 5 MHz

(c) 5 to 6.5 MHz

(d) 6.5 to 10 MHz

I have been asked this question in semester exam.

The above asked question is from Arrhythmias Monitor in chapter Arrhythmia and Ambulatory Monitoring Instruments of Biomedical Instrumentation

Answer 1

Correct answer is (b) 0.4 to 5 MHz

The explanation is: Electrosurgery machines generate RF signals within a range of 0.4 to 5 MHz with peak-to-peak amplitudes of 100 to 1000 V, pulse modulated at rates from 1.5 to 25 kHz for coagulating or 120 Hz for cutting. Cardiac monitors are often used in operation theatres, where the RF is applied through a pointed scalpel at the point of incision and the return path for the current is through a wide area electrode on the opposite side of the patient’s body.