CABT Fundamentals of Electronics 4

Question 1

What is the purpose of electrical isolation in patient-connected biomedical equipment?

Accepted Answer

To prevent leakage current from passing through the patient

Answer

Electrical isolation prevents potentially lethal leakage currents from flowing through the patient by breaking the direct electrical connection between the equipment and the patient.

Question 2

The term 'slew rate' in an operational amplifier refers to:

Accepted Answer

Maximum rate of change of output voltage

Answer

Slew rate is the maximum rate at which the op-amp output voltage can change, typically expressed in V/µs, limiting high-frequency large-signal performance.

Question 3

Which semiconductor device is most suitable for controlling large currents in medical power supplies using a low-power control signal?

Accepted Answer

MOSFET

Answer

MOSFETs are voltage-controlled devices with very high input impedance, capable of switching large currents with minimal gate drive power, making them ideal for power supply control.

Question 4

In an EEG amplifier, why is a notch filter at 60 Hz commonly used?

Accepted Answer

To eliminate power line interference from the signal

Answer

A 60 Hz notch filter selectively attenuates power line frequency interference while passing the EEG signal frequencies (0.5–100 Hz).

Question 5

What does the term 'ground loop' refer to in biomedical electronics?

Accepted Answer

Unwanted current flow through multiple ground paths causing interference

Answer

Ground loops occur when multiple ground connections form a loop, allowing small potential differences to drive circulating currents that introduce noise into sensitive measurements.

(CABT) Certified Associate in Biomedical Technology Practice Test

(CABT) Certified Associate in Biomedical Technology Practice Test

CABT Fundamentals of Electronics 4