Fig. 6
HySE enables quantification of physiological information. a Photograph of chicken bone tissue on a Petri dish. The overlaid false colour region indicates the hyperspectral imaging (HSI) area and shows the two tissue regions identified using principal component analysis and k-means (k = 2) clustering. b Representative slice images from the hypercube in the region of the dashed line in a at four wavelengths. The colour bars indicate relative absorbance. c Spectra of the identified clusters shown in a. d Schematic of tissue phantom with blood-filled tubes at four different oxygen levels indicated by (i)–(iv): (i) fully oxygenated blood; (ii, iii) partially oxygenated blood; (iv) fully deoxygenated blood. e Representative slice images from the hypercube at four wavelengths. Dashed line indicates tube boundaries, which are not absorbing. f Normalised absorbance spectra of the blood samples. g Quantitative comparison of partial oxygen pressure (pO2) measured by a reference probe and oxygen saturation (sO2) calculated by linear spectral unmixing of measured tube spectra. Solid lines and shaded areas in c, f indicate mean value and standard deviation of the absorbance profile, respectively. Error bars in g represent standard deviation in bars and lines. Images acquired using external illumination. Scale bars a, b = 2 mm. Scale bar e = 3 mm
