|
We present a new experimental setup specialized in creating retinal models with real human blood flow that controls or measure many sources of imaging variability. This will assist with extracting the core physical principles required to better understand in-vivo OCT, doppler OCT, and spectroscopic SLO data, to build better retinal imaging devices.
Our setup consists of two components, developed simultaneously. The first component is a flow system with the calibration methods needed to drive human whole blood through a closed-loop system. Controls include fluid pressure/flow rate (via pump speed) and the oxygenation level of the blood (via a gas exchange component). This results in a flow characterized by sensors measuring blood oxygenation saturation, temperature, pH, and flow rate through our model eye.
The second setup component is the model eye. We have created silicone elastomer-based phantoms with flow channel diameters matching typical vasculature dimensions of a human retina (50 – 150 µm). These phantoms are embedded in a custom-built housing which mimics the optics of the eye. This makes the flow medium running through the phantom’s capillary easily accessible by any optical measurement technique for analysis. The optical scattering properties of the model eye, as well as phantom geometry, can be manipulated at fabrication to suit the requirements of the experiments being performed, and can be easily interchanged in the flow system.
We present initial results on imaging the flow channel with an intralipid scattering medium and human whole-blood using an optical coherence tomography (OCT) setup built for ophthalmic applications. The goal of this research project is to quantify blood flow velocity from the dynamic OCT speckle patterns seen in sequential flow-channel images (Doppler OCT).
|
