Reconstructed State Space Features for Classification of ECG Signals

Figures

• 

  Figure 1. Instances of A) normal, B) Ventricular Tachycardia (VT), C) Ventricular Fibrillation (VF), D) Supraventricular Tachycardia (SVT) signals to demonstrate external similarities in the time domain.

• 

  Figure 2. The block diagram representing the proposed algorithm.

• 

  Figure 3. The representation for the signal transmitted to the state space. A) Normal signal B) Ventricular Tachycardia (VT) signal C) the gridded state space image for the normalized signal D) the gridded state space image for the VT E) Supraventricular Tachycardia (SVT) signal F) Ventricular Fibrillation (VF) signal G) the gridded state space image for the SVT H) the gridded phase space image for the VF.

• 

  Figure 4. The masks utilized to remove common information, (A), (E), (F) and (G) with -45 degree angles and thicknesses of 15, 3, 7, and 10 pixels, (C) and (D) with thicknesses of 40 and 20 pixels, (H) and (B), which are vertical and horizontal, respectively, with thicknesses equivalent to 50pixels.

• 

  Figure 5. Time delay and normalized mutual information (NMI) ratios, along with the illustration of the globally optimal time delay for (A) Normal-Supraventricular Tachycardia (SVT), (B) Ventricular Tachycardia (VT)-SVT, (C) N-Ventricular Fibrillation (VF) and (D) VF-VT

• 

  Figure 6. The results were obtained after applying the masks presented in Figure 4 and some of the introduced features. In these figures, rows 1, 3, and 5, refer to the VF images, while 2nd,4th, and 6th rows represent the normal images. In addition, Figures A) and D) illustrate the center of mass; B) and E) demonstrate applying -45 degrees masks with thicknesses of 15 pixels; C) and F) illustrates applying -45 degrees masks with thicknesses of 10 pixels; G) and J) demonstrate applying -45degrees masks with thicknesses of 7 pixels; H) and K) illustrate applying -45degrees masks with thicknesses of 3 pixels images shown in I) and L); results from applying the mask presented in Figure 4 (C), M) and P) from applying the mask presented in Figure 4 (D), and images N) and Q) represent applying the “opening” operator, followed by considering the area, and finally O) and R) images demonstrate applying the mask presented in Figure 4 (B) and determining the center of mass in the images.