A novelty technique for the fabrication of biomedical optics phantoms with cyst-mimicking inclusions

Abstract

The construction of standardised phantoms for biomedical optics experiments is still a developing research field. Particularly, the application of diffusive optics techniques to tissues with low or non-scattering heterogeneities, such as cysts, where the diffuse approximation does not apply, has been studied during the last years. The reported phantoms for mimicking cysts have inclusions that consist of hollow cylinders filled with low or non-scattering fluids, being thus more representative of a 2D geometry rather than a 3D geometry. We present here an innovative proposal, to our knowledge not reported before, for the manufacture of solid diffusive phantoms with spherical, liquid inclusions, with low or non-scattering properties, intended to reproduce cysts. To this end, we used the inverse spherification technique from the molecular gastronomy. The constructed phantoms were optically characterised by two approaches, namely whole field continuous wave transmittance imaging and time-resolved experiments, both in the near infrared at λ = 785 nm. After optical characterisation, the phantoms were also dissected, showing that the inclusions remained in place and preserved their shape after the whole fabrication process. Some results were also validated by Monte Carlo simulations.