Measurement Of Ocular Pulse Of Anterior Chamber Based On Spectral Domain OCT System

Ocular pulse(OP)is an important basis for evaluating the biomechanical properties of eye tissues,and plays an important role in the diagnosis of early glaucoma and age-related macular disease.Ocular pulse in the anterior chamber(a OP)has been visualized in the eyes of mice,but not yet in human eyes.In order to characterize the ocular pulse in the anterior chamber of healthy human eyes,the work obtains anterior chamber image information based on Spectral Domain Optical Coherence Tomography(SD-OCT),and obtains pulsation information by performing phase processing on it.The main research content and the innovative research results obtained are as follow:First,a fiber-optic spectral domain optical coherence tomography system(SDOCT)with a center wavelength of 840 nm was developed.The theoretical longitudinal resolution of the system is 7μm,the lateral resolution is 15μm,and the maximum imaging depth is 4 mm.The scan rate is 120 KHz,which can realize high-resolution real-time imaging in the depth direction of biological tissues and provide imaging tools for the measurement of anterior chamber pulsation.Secondly,a calibration method of spectrometer is proposed,which can improve the imaging quality of the system.The method is based on a Michelson interferometer with a common optical path,and uses the phase distribution of the interference spectrum to calibrate the wavelength of the spectrometer.The common optical path interference has the characteristics of automatically matching the system dispersion,which can eliminate the influence of the system dispersion on the phase extraction,and make the calibration accuracy of the wavelength distribution on the spectrometer higher.Third,the Full-range imaging technology is introduced to eliminate the conjugate image caused by the Fourier transform symmetry in the system.This technology does not increase the complexity of the system,mainly by making the beam deviate from the center optical path of the galvanometer,and the increased optical path difference of the offset optical path causes the interference signal to introduce a rated modulation signal,which is used to eliminate the Fourier transform conjugate matrix,thereby obtaining The correct anterior chamber image can be used to extract pulsation information.Fourth,a pulsation measurement algorithm is proposed,which for the first time realizes the measurement of the ocular pulse in the anterior chamber of healthy eyes.The algorithm mainly tracks the displacement movement of the cornea and lens by extracting the phase difference between adjacent images.Evaluate the motion phase of large tissues with linear motion trends and a high-order phase compensation algorithm is used to eliminate the noise phase,so as to extract the pulsating phase.