FOCUSING ALGORITHM IN OCT-ONLY SYSTEMS

摘要

In an OCT system, the autocorrelation signal depends only on the strength of the signal in the object arm scattered back from a patient's retina and is a result of different reflections from different layers of the retina interfering with each other. The strength of the autocorrelation signal depends on how well focused the system is. Normally the autocorrelation signal is treated as noise. However by removing the reference path signal, the autocorrelation signal is easily measured and analyzed. The optimal focus can the then be found by adjusting the focus value until the autocorrelation signal is maximized.

主权项

1. A method of focusing a spectral optical coherence tomography (OCT) system, comprising:
eliminating an OCT signal that is caused by interference between a beam in a reference arm of the OCT system and a beam in an object arm of the OCT system; setting a focus of the OCT system at a variety of values; for each focus value, measuring the signal strength of a beam reflected from a patient's eye, and storing the measured signal strength and the focus value is association with each other; determining a maximum of the stored signal strengths; determining as an optimal focus value the focus value stored in association with the maximum of the stored signal strengths; and setting the focus of the OCT system to the optimal focus value.