Biomedical Instrumentation Questions and Answers – System Concepts

This set of Biomedical Instrumentation Multiple Choice Questions & Answers (MCQs) focuses on “System Concepts”.

1. Which of the following instrument records the electrical activity of the heart?
a) VCG(Vectorcardiograph)
b) PCG(Phonocardiograph)
c) ECG(Electrocardiograph)
d) EEG
View Answer

Answer: c
Explanation: The electrocardiograph (ECG) is an instrument, which records the electrical activity of the heart. Electrical signals from the heart characteristically precede the normal mechanical function and monitoring of these signals has great clinical significance.

2. Electrocardiography are used in catheterization laboratories, coronary care units and for routine diagnostic applications in cardiology.
a) True
b) False
View Answer

Answer: a
Explanation: True, electrocardiographs are used in catheterization laboratories, coronary care units and for routine diagnostic applications in cardiology.

3. Who provides valuable information about a wide range of cardiac disorders?
a) VCG
b) ECG
c) PCG
d) EEG
View Answer

Answer: b
Explanation: ECG provides valuable information about a wide range of cardiac disorders such as the presence of an inactive part (infarction) or an enlargement (cardiac hypertrophy) of the heart muscle.
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4. What is diagnostically useful frequency range?
a) 0.025 to 0.05 Hz
b) 0.05 to 150 Hz
c) 150 to 200 Hz
d) 0.05 to 150 MHz
View Answer

Answer: b
Explanation: Although the electric field generated by the heart can be best characterized by vector quantities, it is generally convenient to directly measure only scalar quantities, i.e. a voltage difference of mV order between the given points of the body. The diagnostically useful frequency range is usually accepted as 0.05 to 150 Hz (Golden et al 1973).

5. Which machines CMRR is of order of 100-120 dB?
a) VCG
b) PCG
c) EEG
d) ECG
View Answer

Answer: d
Explanation: CMRR of the order of 100–120 dB with 5 kW unbalance in the leads is a desirable feature of ECG machines. In addition to this, under specially adverse circumstances, it becomes necessary to include a notch filter tuned to 50 Hz to reject hum due to power mains.

6. How many paper speeds are necessary for ECG recording?
a) One
b) Minimum two
c) Can be any
d) Max two
View Answer

Answer: b
Explanation: The instability of the baseline, originating from the changes of the contact impedance, demands the application of the automatic baseline stabilizing circuit. A minimum of two paper speeds is necessary (25 and 50 mm per sec) for ECG recording.

7. Where are potentials picked up by patient electrodes taken to?
a) Lead Selector switch
b) Preamp
c) Power Amplifier
d) Instrumentational amplifier
View Answer

Answer: a
Explanation: The potentials picked up by the patient electrodes are taken to the lead selector switch. In the lead selector, the electrodes are selected two by two according to the lead program.
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8. How lead selector selects electrodes?
a) one by one
b) two by two
c) three by three
d) four by four
View Answer

Answer: b
Explanation: The potentials picked up by the patient electrodes are taken to the lead selector switch. In the lead selector, the electrodes are selected two by two according to the lead program.

9. The amplified output signal is picked up single-ended from preamp and is given to the _________
a) Power Amplifier
b) Lead Selector
c) Pen Motor
d) Paper motor
View Answer

Answer: a
Explanation: The preamplifier is usually a three or four stage differential amplifier having a sufficiently large negative current feedback, from the end stage to the first stage, which gives a stabilizing effect. The amplified output signal is picked up single-ended and is given to the power amplifier. The power amplifier is generally of the push-pull differentical type.
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10. Why is preamplifier used?
a) For Amplification
b) For Stabilizing effect
c) For Reducing effect
d) For Modifying effects
View Answer

Answer: b
Explanation: The preamplifier is usually a three or four stage differential amplifier having a sufficiently large negative current feedback, from the end stage to the first stage, which gives a stabilizing effect.

11. ‘Stand by’ mode of operation is generally provided in which instrument?
a) VCG
b) PCG
c) ECG
d) EMG
View Answer

Answer: c
Explanation: A‘stand by’ mode of operation is generally provided on the electrocardiograph. In this mode, the stylus moves in response to input signals, but the paper is stationary. This mode allows the operator to adjust the gain and baseline position controls without wasting paper.

12. ________ are made horizontally on electrocardiogram.
a) Time Measurements
b) Heart Rate Measurements
c) Time Measurements and Heart Rate Measurements
d) Not fixed and can be any thing
View Answer

Answer: c
Explanation: Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals. Time measurements and heart rate measurements are made horizontally on the electrocardiogram.

13. What is paper recording speed for routine work?
a) 10 mm/s
b) 15 mm/s
c) 20 mm/s
d) 25 mm/s
View Answer

Answer: c
Explanation: Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals. Time measurements and heart rate measurements are made horizontally on the electrocardiogram.

14. What measurements are made vertically on electrocardiogram?
a) Time Measurements
b) Heart Rate Measurements
c) Amplitude Measurements
d) Time Measurements and Heart Rate Measurements
View Answer

Answer: c
Explanation: Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals. Time measurements and heart rate measurements are made horizontally on the electrocardiogram. Amplitude measurements are made vertically in millivolts.The sensitivity of an electrocardiograph is typically set at 10 mm/mV.

15. What is sensitivity of an electrocardiograph?
a) 10 mm/mV
b) 15 mm/mV
c) 20 mm/mV
d) 25 mm/mV
View Answer

Answer: a
Explanation: Electrocardiograms are almost invariably recorded on graph paper with horizontal and vertical lines at 1 mm intervals with a thicker line at 5 mm intervals. Time measurements and heart rate measurements are made horizontally on the electrocardiogram. Amplitude measurements are made vertically in millivolts. The sensitivity of an electrocardiograph is typically set at 10 mm/mV.

Sanfoundry Global Education & Learning Series – Biomedical Instrumentation.

To practice all areas of Biomedical Instrumentation, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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