Biomedical Instrumentation Questions and Answers – Multi-Patient Telemetry

This set of Biomedical Instrumentation Multiple Choice Questions & Answers (MCQs) focuses on “Multi-Patient Telemetry”.

1. _____________ instrument is used for recording the electrical activity of the brain.
a) ECG
b) PCG
c) EEG
d) EMG
View Answer

Answer: c
Explanation: EEG, describing the general function of the brain activity, is the superimposed wave of neuron potentials operating in a non-synchronized manner in the physical sense. Electroencephalograph is an instrument for recording the electrical activity of the brain, by suitably placing surface electrodes on the scalp.

2. EEG electrodes are smaller in size than ECG electrodes.
a) True
b) False
View Answer

Answer: a
Explanation: EEG electrodes are smaller in size than ECG electrodes. Several types of electrodes may be used to record EEG. These include: Peel and Stick electrodes, Silver plated cup electrodes and Needle electrodes.

3. Which of the following is the superimposed wave of neuron potentials operating in a non-synchronized manner in a physical sense?
a) EEG
b) ECG
c) VCG
d) PCG
View Answer

Answer: a
Explanation: Electroencephalograph is an instrument for recording the electrical activity of the brain, by suitably placing surface electrodes on the scalp. EEG, describing the general function of the brain activity, is the superimposed wave of neuron potentials operating in a non-synchronized manner in the physical sense.
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4. ______________ material is used to improve electrical contact in electrodes with the skin.
a) Silver Tungsten
b) Copper Tungsten
c) Electrode jelly
d) Silver Graphite
View Answer

Answer: c
Explanation: If the electrodes are intended to be used under the skin of the scalp, needle electrodes are used. Electrode jelly or paste is used to improve the electrical contact. They offer the advantage of reducing movement artefacts.

5. Which among the following electrode gives high skin impedance as compared to ECG?
a) VCG
b) EEG
c) EMG
d) PCG
View Answer

Answer: b
Explanation: EEG electrodes give high skin contact impedance as compared to ECG electrodes. Good electrode impedance should be generally below 5 kilohms. Impedance between a pair of electrodes must also be balanced or the difference between them should be less than 2 kilohms.
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6. Which of the following component is generally designed to have a very high value of input impedance to take care of high electrode impedance?
a) Montages
b) Filters
c) Electrodes
d) Preamplifiers
View Answer

Answer: c
Explanation: EEG preamplifiers are generally designed to have a very high value of input impedance to take care of high electrode impedance. Good electrode impedance should be generally below 5 kilohms. Impedance between a pair of electrodes must also be balanced or the difference between them should be less than 2 kilohms.

7. What is the recording called in which voltage difference between an active electrode on scalp with respect to reference electrode at ear lobe or any other part of the body is recorded?
a) Unipolar
b) Bipolar
c) Monopolar
d) Nonpolar
View Answer

Answer: c
Explanation: This type of recording is called ‘monopolar’ recording. EEG may be recorded by picking up the voltage difference between an active electrode on the scalp with respect to a reference electrode on the ear lobe or any other part of the body.
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8. Which of the following is employed for a bipolar recording done?
a) Uni Channel EEG
b) Omni channel EEG
c) Non Channel EEG
d) Multi channel EEG
View Answer

Answer: d
Explanation: Such recordings are done with multi-channel electroencephalographs. ‘bipolar’ recording is more popular wherein the voltage difference between two scalp electrodes is recorded.

9. EEG signals picked up by surface electrodes are usually larger as compared to ECG.
a) True
b) False
View Answer

Answer: b
Explanation: They may be several hundred microvolts, but 50 microvolts peak-to-peak is the most typical. Yes, EEG signals picked up by the surface electrodes are usually small as compared with the ECG signals.
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10. A pattern of electrodes on the head and the channels they are connected to is called a montage. Montages are always ___________
a) inverse
b) random
c) symmetrical
d) asymmetrical
View Answer

Answer: c
Explanation: Montages are always symmetrical. A pattern of electrodes on the head and the channels they are connected to is called a montage. The reference electrode is generally placed on a nonactive site such as the forehead or earlobe.

11. Reference electrode for recording EEG is placed on __________
a) forehead
b) cervical
c) nasal
d) facial
View Answer

Answer: a
Explanation: The reference electrode is generally placed on a nonactive site such as the forehead or earlobe. A pattern of electrodes on the head and the channels they are connected to is called a montage. Montages are always symmetrical.

12. The typical value of calibration signal is ________
a) 10 uV/cm
b) 70 uV/cm
c) 50 uV/cm
d) 30 uV/cm
View Answer

Answer: c
Explanation: A typical value of the calibration signal is 50 uV/cm. A calibrating signal is used for controlling and documenting the sensitivity of the amplifier channels. This supplies a voltage step of adequate amplitude to the input of the channels.

13. Preamplifiers used in electroencephalograph have low gain and high noise characteristics for EEG.
a) True
b) False
View Answer

Answer: b
Explanation: It is False. Preamplifier used in electroencephalographs must have high gain and low noise characteristics because the EEG potentials are small in amplitude. In addition, the amplifier must have a very high common-mode rejection to minimize stray interference signals from power lines and other electrical equipments.

14. At what frequency is the notch filter in EEG machines sharply tuned to eliminate mains frequency interference?
a) 60
b) 90
c) 10
d) 70
View Answer

Answer: a
Explanation: EEG machines have a notch filter sharply tuned at 60 Hz so as to eliminate mains frequency interference. The use of notch filters should preferably be restricted to exceptional circumstances when all other methods of eliminating interference have been found to be ineffective. These however have the undesirable property of ‘ringing’ i.e. they produce a damped oscillatory response to a square wave calibration waveform or a muscle potential.

15. ______________ is typical frequency range of standard EEG machines.
a) 70 to 140 Hz
b) 0.1 to 70 Hz
c) 0.05 to 0.1 Hz
d) 0.025 to 0.05 Hz
View Answer

Answer: b
Explanation: The typical frequency range of standard EEG machines is from 0.1 Hz to 70 Hz, though newer machines allow the detection and filtering of frequencies up to several hundred Hertz. This may be of importance in some intracranial recordings.

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 - Founder & CTO at Sanfoundry
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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