Presented at the MIT Big Data annual workshop

1. Understanding ECG signals in
the MIMIC II database
Jiahao Chen and Jake Bolewski, MIT
jiahao.github.io

2. From: Chapter 3, Conquering the ECG, Cardiology Explained. Ashley EA, Niebauer J. London: Remedica; 2004.
ECG signals are very structured

3. From: Chapter 3, Conquering the ECG, Cardiology Explained. Ashley EA, Niebauer J. London: Remedica; 2004.
ECG signals are very structured

4. From: Chapter 3, Conquering the ECG, Cardiology Explained. Ashley EA, Niebauer J. London: Remedica; 2004.
ECGs can reveal many heart problems
normal
first-degree heart block
atrial fibrillation
atrial flutter
left bundle bunch block
etc…
How can we build a computer model for all of these?

5. Characterization strategy
database waveform record features statistics
convert file formats
find valid records
PCA, etc.

6. Challenges
- Missing data
- Not all 12 leads present - some symptoms cannot be diagnosed
- Incomplete waveforms - ignore for now
- Weird data - data acquisition problem? coding error? our own
ignorance?

7. Characterization strategy
database waveform record features statistics
???

8. What features are we after?
Some criteria for pathology are known precisely.
More generally, we want to find abnormalities. But we need to
understand normal behavior first.
Others are more vague.

9. A model for normal behavior
Patrick E. McSharry, Gari D. Clifford, Lionel Tarassenko, and Leonard A. Smith, "A Dynamical Model for Generating Synthetic
Electrocardiogram Signals", IEEE Transactions in Biomedical Engineering, 50(3), 2003, 289--294.* doi:10.1109/TBME.2003.808805

10. A model for normal behavior
Patrick E. McSharry, Gari D. Clifford, Lionel Tarassenko, and Leonard A. Smith, "A Dynamical Model for Generating Synthetic
Electrocardiogram Signals", IEEE Transactions in Biomedical Engineering, 50(3), 2003, 289--294.* doi:10.1109/TBME.2003.808805
place and shape of P, Q, R, S, T peaks
breathing
three different sets of physiological features
heartbeat variations described by
another model…

11. http://nbviewer.ipython.org/urls/raw.github.com/jiahao/ijulia-notebooks-assorted/
master/ECG%20model.ipynb
References:
- Patrick E. McSharry, Gari D. Clifford, Lionel Tarassenko, and Leonard A.
Smith, "A Dynamical Model for Generating Synthetic Electrocardiogram
Signals", IEEE Transactions in Biomedical Engineering, 50(3), 2003,
289--294. doi:10.1109/TBME.2003.808805
Barbara J Aehlert, "ECGs Made Easy", 5/e, 2012, Mosby/JEMS.
"Chapter 3: Conquering the ECG". In Ashley EA, Niebauer J, "Cardiology
Explained", London: Remedica; 2004. http://www.ncbi.nlm.nih.gov/books/
NBK2214/
physionet.org
IPython notebook