Processing EKG data
For record[0], one can see that this patient has MLII and V5 leads only. There are usually 12 leads on the body when recording the ECG.
The 12-lead ECG is the standard for a comprehensive view of the heart's electrical activity. It combines three limb leads (I, II, III), three augmented limb leads (aVR, aVL, aVF), and six precordial leads (V1-V6), providing a 360-degree view of the heart.
Each ECG lead provides a view of the heart’s electrical activity from a different angle or perspective. The electrical impulses of the heart are recorded by electrodes placed on the body, and the configuration of these electrodes defines the lead. Each lead captures a unique projection of the heart's electrical signal, giving cardiologists insight into different aspects of heart function.
Lead II (MLII): Provides the clearest and most stable signal for continuous monitoring, often used in telemetry and during surgeries.
Precordial Leads (V1-V6): Essential for diagnosing acute coronary syndromes, including anterior and lateral wall infarctions.
record[0] has these 2 leads:
Lead II (MLII) records the difference in electrical potential between the right arm (negative electrode) and the left leg (positive electrode). It is commonly used because it provides a clear view of the heart's electrical axis, particularly the P waves and QRS complex.
Lead V5 is part of the precordial (chest) leads and is placed on the left side of the chest. It provides a horizontal view of the heart, focusing on the lateral aspect of the left ventricle.
Image compression of Sharbat Gula from National Geographic. Using Fast Fourier Transform (FFT) on image allows us to threshold small Fourier coefficinets and we can recover the image using the FFT inverse.