Non-contact diffuse optical tomography

We present a simple and novel theoretical approach for modeling the intensity distribution from an arbitrarily shaped turbid volume in a non-contact geometry by considering diffuse light propagation in free-space. Optical tomography of turbid media has so far been limited by systems that require fixed geometries or fiber measurements. This novel theory is validated with experiments for a diffusive volume of known geometry in a non-contact situation, both with and without the presence of an embedded absorber. We also present a system that records non-contact optical measurements from diffuse media of arbitrary shapes and retrieves the three-dimensional surface information of the diffuse medium. This approach offers significant experimental simplicity and yields high-information content datasets. The performance of this novel tomographic approach is demonstrated with experimental reconstructions of phantoms. Finally, the implications of this new formulation in the context of optical tomography in turbid media are discussed.