194
Biomedical Signal and Image Processing
PROBLEMS
9.1 Import the data in the file “p_9_1.xls” in MATLAB ® and plot the signal.* In
order to do so, use File/Import Data… on the main MATLAB menu and follow the steps in loading and naming of the data. The file contains the signals
of a two-electrode recording of a normal ECG over a period of 1 min.
a. Determine the PP interval and the RR interval for both signals.
b. Use DFT to describe the signals in the frequency. Determine the heart rate.
c. Iso late one typical period of the signal, i.e., one cycle containing P-QRS-T.
Calculate the duration of P, T, and QRS waves.
d. Co mment on the differences between the values captured in parts a, b, and c
across the two signals.
9.2 Import the data in the file “p_9_2.xls” and plot the signals. The file contains
the signals of an eight-electrode recording of an abnormal ECG describing AF.
Choose the signal of recording II for your analysis.
a. Repeat the calculations in parts a, b, and c of Problem 9.1 on the recording II.
b. Compare a single period with one period of the signal in Problem 9.1 and
comment on the differences.
9.3 Import the data in the file “p_9_3.xls” and plot the signals. This signal is one
recording out of 12 recordings of an ECG with bundle-branch block. For this
ECG signal, we focus on the signals in the recordings I and II.
a. Repeat the calculations in parts a, b, and c of Problem 9.1 on the recordings
I and II.
b. Using “wavemenu” and Daubeches 1 mother wavelet, decompose the signal
into five levels. Comment on the contents of each decomposition level. Apply
denoising option to filter out the noise.
c. Repeat part b using Daubeches 2 mother wavelet.
d. Compare a single period with one period of the signal in Problem 9.1 and
comment on the differences.
9.4 Import the data in the file “p_9_4.xls” and plot the signal. This is a fifteen-channel recording of a myocardial infarction ECG. Use signal II for the following
analyses:
a. Repeat the calculations in parts a, b, and c of Problem 9.1 on the recording II.
b. Using “wavemenu” and Daubeches 1 mother wavelet, decompose the signal
into five levels. Comment on the contents of each decomposition level. Apply
denoising option to filter out the noise.
c. Repeat part b using Daubeches 2 mother wavelet.
d. Compare a single period with one period of the signal in Problem 9.1 and
comment on the differences.
* All ECG recordings in the problem section of this chapter were taken from PhysioNet,
http://www.physionet.org/. The research resource for complex physiologic signals: MIT, Cambridge, MA.
Biomedical Signal and Image Processing
PROBLEMS
9.1 Import the data in the file “p_9_1.xls” in MATLAB ® and plot the signal.* In
order to do so, use File/Import Data… on the main MATLAB menu and follow the steps in loading and naming of the data. The file contains the signals
of a two-electrode recording of a normal ECG over a period of 1 min.
a. Determine the PP interval and the RR interval for both signals.
b. Use DFT to describe the signals in the frequency. Determine the heart rate.
c. Iso late one typical period of the signal, i.e., one cycle containing P-QRS-T.
Calculate the duration of P, T, and QRS waves.
d. Co mment on the differences between the values captured in parts a, b, and c
across the two signals.
9.2 Import the data in the file “p_9_2.xls” and plot the signals. The file contains
the signals of an eight-electrode recording of an abnormal ECG describing AF.
Choose the signal of recording II for your analysis.
a. Repeat the calculations in parts a, b, and c of Problem 9.1 on the recording II.
b. Compare a single period with one period of the signal in Problem 9.1 and
comment on the differences.
9.3 Import the data in the file “p_9_3.xls” and plot the signals. This signal is one
recording out of 12 recordings of an ECG with bundle-branch block. For this
ECG signal, we focus on the signals in the recordings I and II.
a. Repeat the calculations in parts a, b, and c of Problem 9.1 on the recordings
I and II.
b. Using “wavemenu” and Daubeches 1 mother wavelet, decompose the signal
into five levels. Comment on the contents of each decomposition level. Apply
denoising option to filter out the noise.
c. Repeat part b using Daubeches 2 mother wavelet.
d. Compare a single period with one period of the signal in Problem 9.1 and
comment on the differences.
9.4 Import the data in the file “p_9_4.xls” and plot the signal. This is a fifteen-channel recording of a myocardial infarction ECG. Use signal II for the following
analyses:
a. Repeat the calculations in parts a, b, and c of Problem 9.1 on the recording II.
b. Using “wavemenu” and Daubeches 1 mother wavelet, decompose the signal
into five levels. Comment on the contents of each decomposition level. Apply
denoising option to filter out the noise.
c. Repeat part b using Daubeches 2 mother wavelet.
d. Compare a single period with one period of the signal in Problem 9.1 and
comment on the differences.
* All ECG recordings in the problem section of this chapter were taken from PhysioNet,
http://www.physionet.org/. The research resource for complex physiologic signals: MIT, Cambridge, MA.