Grad_CAM for time series

I am new to deep learning and trying to build a Grad-cam from time series data. Shape of my input sample is (188,1), its an ECG signal and I have a cnn-1D model for classification. Keras provides function Grad-cam for images(2D). I am trying to convert this function for 1D time-series data. Could anyone please help me how to do it. Thank you in anticipation.