Inspiration of Prototype Knowledge: Introducing a Meta-Learning Approach to Heart Sound Classification

Cardiovascular diseases (CVDs) stand as the primary reason of fatalities globally, especially in low- and middle-income countries. In recent years, with the leverage of computer audition technologies, the diagnosis of CVDs through heart sounds become a popular topic. Current models and techniques are trained, validated, and tested on the same dataset, which need to be retrained when encountering new data. To make the best use of sparse data, we propose a Prototypical Network framework with heuristic weight for heart sound recognition. After extracting two different features (Mel Spectrogram and Mel Frequency Cepstral Coefficients) and encoding the features, we calculate the distance between two categories (normal and abnormal), then, a heuristic weight is assigned to the distance that makes the blurred boundaries more distinct. By considering the subject independence, the Unweighted Average Recall (UAR) on the PhysioNet/CinC Challenge 2016 is 68.2 % and 67.7 % on two features, respectively. The capability of our model to work on different datasets is proved by a UAR of 66.4 %, which exceeds the baseline UAR of 58.6 % under a single model.