Figure 2
From: Atrial fibrillation designation with micro-Raman spectroscopy and scanning acoustic microscope
Raman spectroscopy-based classification of the measured tissue samples. (a) Comparison of group means. (b) PC loadings of the spectral distribution of the first three PCs whose TVEs are about 76%. We used these PCs in the k-means analysis. (c) Determination of group indices by using principal component analysis (PCA). PC1 (with total variance explained (TVE) of 47%) vs. PC2 (TVE of 23%) plot shows the Euclidean distance between the PC scores, which were further used in the k-means analysis for the determination of group identities. (d) Chemical comparison of PC loadings by means of their responses at particular band positions. Variations of peak positions at 1040, 1295 and 1657 (proline, fatty acids, and Amide I) were investigated. (e) Raman spectrum of Stearic Acid (Provided by FDM Raman organics library). (f) Raman spectrum of Proline measured in our lab.
