The Research of Two-dimensional Heart Sound Recurrence Plot

To highlight some characteristics of heart sound, it was converted into recurrence plot.(1) To meet the requirement of recurrence plot for shorter data processing, equal-part and equal-length processing was used, avoided the segmentation of S1, S2. (2) Aimed at the higher requirement of threshold on recurrence plot, an adaptive threshold acquisition method was proposed. The recognition rate was improved by 10% -30% when compared with other methods. (3) Considered the complexity of heart sound, a multi-threshold fusion heart sound recurrence plot was constructed. (4) When two-dimensional feature were extracted from it, the recognition rate could reach to 90-95%, improved by 5% -20% when compared with other algorithms.