| The trabecular meshwork is a sieve-like structure that mainly controls the passage of aqueous humor,thereby regulating intraocular pressure.The abnormality of intraocular pressure is related to the biomechanical properties of the trabecular meshwork.Increased intraocular pressure is considered to be the most important cause of glaucoma.The main reason.Spectral Domain Optical Coherence Tomography(SDOCT)is a rapidly developing medical imaging technology.It uses the low-coherence characteristics of broadband light sources to achieve high-precision imaging of reflective layers of different depths in biological tissues.Due to the outstanding advantages of OCT technology(non-invasive,non-destructive,non-contact,high resolution,fast imaging speed,etc.),after the appearance of OCT technology,it was quickly applied to the field of ophthalmology and clinical medicine,becoming CT,MRI,and ultrasound technology.Later,another revolutionary breakthrough in the field of medical imaging.Therefore,the accurate detection of biomechanical properties at the trabecular meshwork is expected to provide a technical means for the early detection of glaucoma.In this project,a set of SD-OCT system based on optical fiber was built,and the measurement of pulsation parameters of human eye trabecular meshwork was studied around it.The specific research contents are as follows:(1)Design and build an SD-OCT imaging system based on the optical fiber optical path in the 1060 nm band.Combined with the imaging principle of OCT technology,the main parameters affecting the SD-OCT system are discussed.The detection depth of this system reaches 2.8mm,the axial resolution in air reaches 6.98μm,the frame rate reaches 250 fps/s,and the interference signal of the plane mirror is obtained by using this system.By analyzing the phase information of the interference signal,the light source and stability of the SD-OCT system verified the effectiveness of the SD-OCT system built.(2)In order to improve the lateral resolution of the system,a set of focusing lens groups suitable for anterior chamber imaging is designed.The precision focusing lens takes into account the refraction of the light source at the cornea,focuses the refracted light,and focuses the focus to Corner.The precision focusing lens group is added to the sample arm of the SD-OCT imaging system to achieve a lateral resolution of 13 μm.(3)In order to detect the biomechanical properties of the trabecular meshwork,the method proposed in this paper to measure the biomechanical properties of the trabecular meshwork is a brand-new measurement method.The SD-OCT system was used to image the corner of the atrium of a normal person’s eye,positioned at the range of 2mm from the limbus of the sclera to the cornea,and collected 1000 cross-sectional views at the same position,400 A-lines per picture,and the interval between each picture.2.5ms.During data acquisition,the involuntary rotation of the human eye and the heart beat will cause errors in the extraction of trabecular meshwork dynamic parameters.In response to this problem,this paper proposes a histogram phase compensation algorithm that can effectively remove large tissue movements For the resulting phase shift problem,the phase at the trabecular meshwork is subtracted from the phase at the cornea,which is the extracted pulsation information at the trabecular meshwork.This method can more accurately measure the biomechanical properties at the trabecular meshwork.Quantitative calculation of the changes in tissue at the trabecular meshwork with pulse movement will help to further understand the pathogenesis of glaucoma and provide technical support for the prevention,diagnosis and treatment of glaucoma. |
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