Biomedical Instrumentation Multiple Choice Questions on “Central Monitors”.
1. Which one of the following is not the category of ECG compression techniques?
a) Transformation domain
b) Parameter Extraction
c) Frequency domain
d) Time domain
Answer: c
Clarification: Several ECG compression techniques have been proposed in the last few decades. These techniques can be classified into three major categories: i) Time domain ii) Transformation domain iii) Parameter Extraction.
2. The scan-along polygonal approximation and the amplitude zone time epoch coding are the examples of the __________ category of ECG compression techniques.
a) Transformation domain
b) Time domain
c) Parameter extraction
d) Frequency domain
Answer: b
Clarification: In the time domain category, the compression technique is applied directly to the samples of the ECG signal in the time domain to remove redundant information. Examples include the scan-along polygonal approximation and the amplitude zone time epoch coding.
3. Which of the following techniques are not included in the transformation domain category?
a) Wavelet transform
b) Discrete cosine transform
c) Fourier descriptors
d) Combine discrete cosine and Fourier transform
Answer: d
Clarification: In the transformation domain category, ECG samples are transformed to another domain. Examples include Fourier descriptors, discrete cosine transform, wavelet transform and combine discrete cosine and wavelet transform.
4. Who suggests a new discrete wavelet transform for compressing ECG signals with minimum loss of diagnostic information?
a) Alshamali
b) Friesen
c) Al-Ajlouni
d) Cox and Nolle
Answer: c
Clarification: Various Wavelet-based ECG compression techniques have been found to give lower distortion for the same compression ratios. A new discrete wavelet transform has been suggested by Al-Ajlouni for compression ECG signals with minimum loss of diagnostic information.
5. Full form of AZTEC _______________
a) Amplitude Zone Tech Epoch Coding
b) Amplitude Zone Time Epoch Coding
c) Arrhythmia Zone Tech Epoch Coding
d) Arrhythmia Zone Time Epoch Coding
Answer: b
Clarification: Cox and Nolle suggested AZTEC (Amplitude-Zone-Time-Epoch-Coding) a pre-processing program for real-time ECG rhythm analysis at an approximate data reduction rate of 10:1.
6. AZTEC contains digital logic, which is able to detect?
a) Baseline wander
b) QRS complex
c) R-R interval
d) Motion artifact
Answer: a
Clarification: AZTEC contains digital logic, which is able to detect base line wander. Also, the sum of absolute values of all slopes is used for noise detection, but sudden bursts of muscle artifact or an excursion from baseline are distinguishable from an ECG wave only if the condition persists.
7. A signal of poor quality that cannot be processed is called chaotic.
a) True
b) False
Answer: a
Clarification: The module runs once every second, depending upon the quality of the signal. If the signal is ‘chaotic’ (a signal of poor quality that cannot be processed) or ‘noisy’ (a signal of intermediate quality), no processing is carried out.
8. In the detection of the waveform of ECG signal, a wave is considered as a T wave if _______
a) It occurs within a 120 ms interval
b) Its peak occurred within 1/6th the R-R interval
c) It occurs within a 200 ms interval
d) Its peak occurred within 1/3rd the R wave height
Answer: c
Clarification: AT wave following a QRS is also searched. A wave is considered as a T wave if (i) it occurs within a 200 ms interval, (ii) its peak occurred within 1/3rd the R–R interval +80 ms or within 240 ms whichever is greater, following the preceding R wave, and (iii) its height is half the height of a normal R wave.
9. The four measurements of QRS and a fifth measurement called ________ based on height, duration and offset to those of the patient’s normal QRS are compared.
a) QRS polarity
b) R-to-R interval
c) Wiggle
d) Distance D
Answer: d
Clarification: The four measurements of QRS and a fifth measurement called ‘distance D’ based on height, duration and offset to those of the patient’s normal QRS are compared. Beats are classified on the basis of their deviation from the normal and maybe definitely normal, probably normal, probably PVC or definitely PVC.
10. Cox and Nolle suggested AZTEC – pre-processing program for real time ECG rhythm analysis at an approximate data reduction rate of _______________
a) 1:10
b) 10:1
c) 1:20
d) 20:1
Answer: b
Clarification: Cox and Nolle suggested AZTEC (Amplitude-Zone-Time-Epoch-Coding) a pre-processing program for real time ECG rhythm analysis at an approximate data reduction rate of 10:1.