Figure 7

Raman spectra of biological tissue, specifically of bladder, contain significant autofluorescence contributions and require substantial data-pre-processing. The mean raw-spectrum and the standard deviation is displayed for all bladder biopsies, (a) The background-corrected and area-normalized mean-spectra with standard deviation are shown in (b) Normalized correlation coefficient-value occurrence plotted as a normalized histogram, revealing two separate distributions, i.e. background and tissue below and above a correlation-value of approx. 0.7 (c) An example for the separation of background signal and tissue signal, a map of the correlation values is presented for an entire biopsy and the separation, based on the presented threshold value of 0.7, (d) Additionally, the mean and standard deviation spectra are plotted, i.e. for correlation-values < 0.7 (background), (e) and correlation values > 0.7 (tissue), (f).