Non-invasive imaging and characterisation of human foot by multi-probe laser reflectometry and Monte Carlo simulation.

Diffusely backscattered signals from the human foot sole tissues of normal subjects (n = 5) were obtained by multiprobe laser reflectometry. The colour-coded images were constructed from data on the variation of normalised backscattered intensity (NBI), after interpolation and median filtering. The maximum and minimum NBI values at the arch and heel regions of the foot sole, respectively, were observed. The mean NBI at the arch region was significantly higher compared with that at other regions (p < 0.0001). The images of optical parameters of normal tissues show point-to-point variation, attributed to their compositional changes. The pattern of variation of the NBI of a diabetic subject (glucose level 170 mg dl(-1)) was associated with highly significant variation at the lateral sides of the fore- and middle-foot compared with that of normal subjects.