Tissue-mimicking phantoms of human retina with consideration to blood circulation for Doppler optical coherence tomography

摘要

The retina phantom and a method for making pulsating flows of a fluid in human eye retina vessels are described. The retina phantom was made from two-component transparent silicone. A special gel colourant for silicone was used as an absorbing agent and TiO_2 (titanium dioxide) nanoparticles were used as scatterers. The central retinal artery and vein were constructed as a set of related extended cavities in the phantom. The proximal and distal ends of the cavities were connected to standard catheters. First catheter was connected to the fluid supply tank using a flexible transparent tube. The second catheter was connected to a container for the out coming fluid using another tube. Hemodynamic setup for fluid supply contains: i) a tank with sufficient quantity of the fluid; ii) a pump for making a laminar fluid flow; iii) a unit to make laminar to turbulent flow transformation regime; iv) flow meter and control unit. Periodically repeated controlled twisting of a flexible tube with a laminar flow was used to make pulsations. Vibrations were used to simulate flow changes associated with patient movements and tremor. The described system can be used for developing quantification algorithms to study relative changes and absolute values of blood flow velocity using ophthalmic Doppler optical coherence tomography systems.