Figure 4
Images of the position scanning photoacoustic spectroscopy over time. (a) Images recorded for two hours in 30-min intervals. Scale bar is 250 µm. (b)–(e) Wavenumber scan over time at two different spots of a region of the index finger tip: (b) and (c) where there was no secretion, and (d) and (e) with secretion from an eccrine sweat gland. (b) and (d) 1D plots of the PAS spectra for each position. (c) and (e) Color coded representations of the spectral alterations observed for a volunteer.
