| Axial parameters of the eye,such as corneal thickness,anterior depth,lens thickness,vitreous thickness,and axial length,are associated with many intraocular diseases.Accurate acquisition of axial parameters of the eye is of great significance for the treatment of intraocular diseases.At present,most of the advanced ophthalmology testing equipment in China needs to be imported from abroad.Most of the self-developed equipment is ultrasonic testing,which has low measurement accuracy,slow measurement speed and low measurement efficiency.In order to improve the measurement accuracy,this paper proposed a non-contact measurement method of eye axial multi-parameter based on optical coherent reflection technology.Firstly,the basic principle of optical coherent reflection technology was studied.After that,the overall scheme of the system was designed according to the basic principle,and two sets of Michelson-type interference systems were constructed.The precise positioning of the interface of different media of eyeball was realized by using low coherence signal.The measurement accuracy was improved by using high coherence signal as measuring scale and wavelength as measuring standard.Then the key components of the system were designed and selected.The zero arm,measuring arm and delay line were designed with emphasis.They realized a rapid measurement of eye axial multi-parameter at one time and provided a starting point for each measurement.The interference signal extraction process and the wave peak localization method were specifically analyzed,and the zero optical path difference position of the low coherence signal was located within 10 sampling points.Finally,the system optical path and the polarization state of the interference light were debugged and a prototype was built for the measurement experiment.The results show that the measuring optical range of the system is 71.3715 mm,and the measuring accuracy is 5.7?m,which meets the technical requirements. |
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