BTC Biomedical Instrumentation & Electrical Fundamentals 2

Question 1

A pressure transducer in a patient monitoring system converts mechanical pressure into which type of output signal?

Accepted Answer

An electrical signal proportional to pressure

Answer

A pressure transducer is an electrochemical sensor that produces an electrical signal (typically voltage or current) directly proportional to the applied mechanical pressure.

Question 2

In biomedical signal conditioning, which circuit stage is primarily responsible for removing unwanted frequency components from a physiological signal before digitization?

Accepted Answer

Filter stage

Answer

The filter stage selectively passes desired signal frequencies while attenuating unwanted noise and interference before the signal reaches the analog-to-digital converter.

Question 3

Common Mode Rejection Ratio (CMRR) is a critical specification for biomedical amplifiers because it describes the amplifier's ability to:

Accepted Answer

Reject noise signals common to both inputs

Answer

A high CMRR means the amplifier rejects interference (such as 60 Hz noise) that appears equally on both differential inputs, preserving the small physiological signal of interest.

Question 4

An isolation transformer used in patient-care areas provides electrical isolation primarily to:

Accepted Answer

Prevent patient electrical shock by eliminating a direct ground reference

Answer

Isolation transformers break the direct electrical connection to ground, preventing a completed shock circuit if a patient or caregiver contacts a live conductor.

Question 5

A biomedical technician needs to pass ECG signals (0.05–150 Hz) while blocking both very low-frequency baseline wander and high-frequency EMG noise. Which filter type should be used?

Accepted Answer

Band-pass filter

Answer

A band-pass filter passes only frequencies within a defined range (e.g., 0.05–150 Hz for ECG), blocking both below-band drift and above-band noise simultaneously.

(BTC) Biomedical Technician Certification Practice Test

(BTC) Biomedical Technician Certification Practice Test

BTC Biomedical Instrumentation & Electrical Fundamentals 2