A 3D-CNN with temporal-attention block to predict the recurrence of atrial fibrillation based on body-surface potential mapping signals

Figures

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  FIGURE 1. Framework of our prediction model of AF recurrence. (A) The distribution of the electrodes. There are 128 electrodes, including 74 on the chest and 54 on the back. (B) The experimental scene. (C) Torso geometries. Torso geometries consist of 128 body surface electrodes and a body torso geometry. (D) 128 electrocardiograms. Different colors show the BSPM of different channels, and there are 128 channels in total. (E) Isopotential map. Different colors indicate different voltage amplitudes, and the darker the color, the lower the voltage. (F) 3D isopotential sequence maps. y and x are the height and width of isopotential map, and time is consistent with the time of the BSPMs.

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  FIGURE 2. Structure diagram of the 3D-CNN classification framework.

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  FIGURE 3. Temporal-attention block and its variants. (A) Temporal-attention block. Two groups of features were obtained by global average pooling (AvgPool) and maximum average pooling (MaxPool), then get the sum of the different features matrices. (B) Temporal-attention A1. Feature acquisition contains only MaxPool. (C) Temporal-attention A2. Different channel features were obtained by MaxPool, and use concatenation to fuse different channel features. (D) Temporal-attention A3. Different channel features were obtained by AvgPool and MaxPool, and use concatenation to fuse different channel features.

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  FIGURE 4. Position of six electrode reference points.

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  FIGURE 5. ECG of lead I (29–93) and lead III (37–29) achieved from BSPM. (A) the original BSPM. The blue line is 93 lead (channel); the red line is 29 lead (channel); and the orange line is 36 lead (channel). (B) The ECG after band-pass filtering. (C) The approximate ECG of lead I and III. The blue line is the approximate ECG of lead I by subtracting lead (channel) 93 amplitude from lead (channel) 29 amplitude; the red line is the approximate ECG of lead III by subtracting lead (channel) 29 amplitude from lead (channel) 37 amplitude; (D) The signal after removing the baseline wander.

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  FIGURE 6. Projection and waveform formation of the transverse plane vectorcardiographic loop of BSPM.

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  FIGURE 7. Original ECG data collected by channels 2, 12, 23, 25, and 36.

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  FIGURE 8. Rendering of the isopotential map of preoperative AF (A) Rendering of the isopotential map at different times. The time in this figure means each sampling time of the isopotential map and the color of each isopotential map represents the magnitude of the voltage amplitude: red represents the maximum relative amplitude, and blue represents the minimum. (B) Conduction order of Torso geometries. Blue circular lines are the location of the different electrodes; red arrow indicate the order of cardiac activations.