Functional signal detection in retinal videos

An optical imaging device of retina function (OID-RF) has been developed to perform measurements of changes in blood perfusion due to neural activity resulting from visual stimulation of the photoreceptors in the human retina. Experiments were performed by measuring the changes in reflected long wave visible (700 nm) light from the retina caused by the retinal activation in response to a visual stimulus. The problem being addressed is that of detecting the signal from the retinal activation in the presence of noise from other sources, including the unstimulated retinal background and other unknown physiological changes. Preprocessing of the raw data was done to eliminate unwanted artifacts, such as blinking or excessive eye movement. Principal Component Analysis (PCA) was used to isolate the functional signal. The results of the analysis showed that regions of the retina that were stimulated could be detected using PCA.