Figure 1.

Construction of bispectrum analysis energy features (A-F) are local bispectrum analysis maps of the central region of six breast tumors. (G) is a complete bispectrum analysis map of RF signal segment x_bs(n_bs). A0 region of (H) represents the diagram of the complete bispectrum analysis, and the non-overlapping region S0 is marked. The S0 region in (I) is divided into three equal parts starting from the origin along the direction of the f₂ axis, obtaining the S1, S2, and S3 regions, respectively. The bispectrum analysis energies of the non-overlapping regions of the S1, S2, S3, and S0 regions are calculated respectively to form four new bispectrum analysis energy features of RF signal segment x_bs(n_bs).