Computational time-of-flight diffuse optical tomography


Imaging through a strongly diffusive medium remains an outstanding challenge, in particular in applications in biological and medical imaging. Here, we propose a method based on a single-photon time-of-flight camera that allows, in combination with computational processing of the spatial and full temporal photon distribution data, imaging of an object embedded inside a strongly diffusive medium over more than 80 transport mean free paths. The technique is contactless and requires 1 s acquisition times, thus allowing Hz frame rate imaging. The imaging depth corresponds to several centimetres of human tissue and allows us to perform deep-body imaging as a proof of principle.

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Fig. 1: Experimental set-up.
Fig. 2: Main experimental results.
Fig. 3: Single-pixel temporal histograms of the photon arrivals transmitted through 2.5 cm (red) and 5 cm (blue) of material.
Fig. 4: Tracking of a hidden object positioned at different positions inside the diffusive medium.
Fig. 5: Numerical simulations of the reconstruction of a hidden object (0.5 mm thickness, 5 mm height, separated by 1 mm).
Fig. 6: Experimental results.

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D.F. acknowledges financial support the Engineering and Physical Sciences Research Council, UK (grants EP/M006514/1 and EP/M01326X/1). Y.W. acknowledges financial support from the Engineering and Physical Sciences Research Council, UK (grants EP/M008843/1 and EP/M011089/1).

Author information

A.L. and A.B. performed experiments and data analysis. A.R., F.T. and Y.W. developed the retrieval algorithms and performed data analysis. The project was devised and led by D.F. R.H. developed the SPAD camera. All authors contributed to the preparation of the manuscript.

Correspondence to Daniele Faccio.

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Lyons, A., Tonolini, F., Boccolini, A. et al. Computational time-of-flight diffuse optical tomography. Nat. Photonics 13, 575–579 (2019).

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