Acceptable errors of eye optical system parameters preoperative biometrics are substantiated. It allows to determine intraocular lens (IOL) optical power with the accuracy that provides the error of planned postoperative refraction within ±0.25 diopters. It was found that depending on the location of the IOL in the patient's eye, allowable error in determining the required IOL optical power for emetropic postoperative refraction is from ±0.3 to ±0.42 diopters, and for the average eye optical system is within ±0.337 diopters. It is shown that allowable error in determining the required optical power of the implanted IOL is provided if geometric parameters of aphakia eye – the average radius of cornea curvature, the IOL location in the eye and the focal length of the virtual paraxial component, are measured with the same permissible errors ±0.055 mm.
Violation of the function of breathing manifested in the form of snoring can lead to a decrease in pulmonary ventilation and a decrease in the level of oxygen in the blood. As a result, it is possible to develop a number of diseases, and even with a fatal outcome. The reasons for the appearance of snoring can be many, which complicates both the diagnosis and treatment of snoring. The creation of objective tools and methods for diagnosing snoring is possible in the case of creating an adequate physical model for air passage in the upper respiratory tract and describing the physical effects that arise in the process of breathing. The physical model of air ducts, created on the basis of the anatomical model, takes into account the influence of all structural elements influencing the passage of air. The appearance of sound during snoring is the result of the ingress of turbulent airflow into the oropharynx and subsequent vibration of the palatine tongue and the vibration of the surface of the soft palate. One possible perspective method for identifying the main cause of snoring can be a spectral analysis of the sounds of snoring.
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