An optical tonometer

Abstract

The present invention discloses an optical tonometer, comprising a light source system, a data processing system and a measuring system, wherein the light source system comprises a tunable laser, a polarization controller and an attenuator, the data processing system comprises a photodetector, an oscilloscope and a data acquisition card, and the measuring system comprises an optical fiber, an optical microcavity and a puncture needle. The optical tonometer can directly measure intraocular pressure with small measurement error.

Description

Technical Field

[0001] The invention relates to the technical field of medical ophthalmology, and in particular to an optical tonometer. Background Art

[0002] Tonometer is an instrument used to measure intraocular pressure, mainly used to assist in the diagnosis of eye diseases such as glaucoma. In the prior art, tonometer products include: non-contact tonometer, applanation tonometer, depression tonometer, contact piezoelectric tonometer, rebound tonometer, etc. Tonometers are usually composed of a corneal shape change generator, a corneal deformation measurement system or a contact corneal device and a pressure change sensor.

[0003] The rebound tonometer uses an innovative patented inductive rebound technology. After the probe is inserted into the tonometer, it is magnetized to produce N / S poles. The instantaneous current of the solenoid in the instrument (lasting about 30 milliseconds) generates an instantaneous magnetic field, causing the magnetized probe to move toward the cornea at a speed of 0.2 m / s (the principle of like poles repelling each other). The probe hits the front surface of the cornea, decelerates, and rebounds. The control switch monitors the solenoid voltage caused by the rebounding magnetized probe. The electronic signal processor and microsensor calculate the speed change value after the probe hits the cornea, and finally converts the integrated information into an intraocular pressure reading. If the intraocular pressure increases, the deceleration of the probe after the impact increases and the duration of the impact is shortened. The Goldmann applanation tonometer and the Schiotz indentation tonometer are load-type pressure gauges, both of which measure direct pressure. Non-contact intraocular pressure measurement, also known as pneumatic intraocular pressure measurement, is a method of measuring intraocular pressure without direct contact between the instrument and the eyeball. During the examination, the gas pulse force in the instrument is used to flatten a specific area in the center of the cornea. The relationship between the force required and the intraocular pressure is used to calculate the intraocular pressure. The gas pulse force and the duration of the pulse increase linearly, and the intraocular pressure value is indirectly calculated based on the duration of the pulse force. The above-mentioned tonometers all indicate the magnitude of intraocular pressure by the amplitude of the change in the shape of the cornea.

[0004] In the prior art, tonometers all indirectly indicate the intraocular pressure by calculating the force per unit corneal deformation caused by external force acting on the cornea. They cannot directly measure the pressure of the contents of the eyeball. At the same time, the measured data is easily affected by the thickness and hardness of the cornea and eyeball wall. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, an embodiment of the present invention provides an optical tonometer, which can directly measure the intraocular pressure with high accuracy.

[0007] The optical tonometer according to an embodiment of the present invention includes a light source system, a data processing system and a measurement system.

[0008] The light source system includes a tunable laser, a polarization controller and an attenuator, wherein the polarization controller and the attenuator are used to adjust the light emitted by the tunable laser.

[0009] The data processing system comprises a photoelectric detector, an oscilloscope and a data acquisition card, wherein the photoelectric detector is electrically connected to the oscilloscope and the data acquisition card respectively.

[0010] The measuring system comprises an optical fiber, an optical microcavity and a puncture needle. The two ends of the optical fiber are respectively connected to the output end of the light source system and the photodetector. The optical microbubble cavity is coupled to the optical fiber. One end of the optical microcavity is closed and the other end is connected to the puncture needle.

[0011] In some embodiments, the two ends of the optical fiber are large-diameter ends, and the middle portion is a small-diameter section, and the small-diameter section is spaced apart from the optical microbubble cavity.

[0012] In some embodiments, the optical microcavity is a light-guiding material.

[0013] In some embodiments, the optical microcavity is a microbubble cavity having a circular protrusion in the middle.

[0014] In some embodiments, a hose is further provided, and both ends of the hose are respectively connected to the optical microbubble cavity and the puncture needle.

[0015] In some embodiments, the hose is a Teflon tube.

[0016] The beneficial effects of the present invention are:

[0017] 1. According to the optical tonometer of the embodiment of the present invention, the laser can be emitted through the light source system, and the laser is transmitted along the optical fiber. When the optical fiber is close to the microbubble cavity, the light field can be introduced and exported to the microbubble cavity through the optical fiber through the evanescent field (in the optical microcavity, the light field is not only confined in the annular structure, but part of the light field will leak into the area near the annular structure, which is called the evanescent field). The light is totally reflected in the microbubble cavity to generate the resonance mode of the whispering gallery mode (WGM). When the puncture needle enters the anterior chamber of the eyeball, the frequency drift of the resonance mode of the whispering gallery mode in the microbubble cavity will be caused by the pressure change. The intraocular pressure value is calculated by directly measuring the drift amount or measuring the change in the transmitted light intensity under the condition of fixed wavelength laser incidence. It has the advantages of high Q value (greater than 10^6), high sensitivity brought by low mode volume, small size and easy integration.

[0018] 2. A Teflon tube is provided between the puncture needle and the microbubble cavity, which converts the intraocular pressure into the air pressure inside the Teflon tube, thereby changing the external environment of the microbubble cavity.

[0019] 3. The optical tonometer of the embodiment of the present invention enters the eyeball through a puncture needle, and the measurement result is not affected by the thickness and hardness of the cornea and the eyeball wall, thereby reducing errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of an optical tonometer according to an embodiment of the present invention;

[0021] Figure 2 It is a partial schematic diagram of a measurement system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings.

[0023] The optical tonometer of the embodiment of the present invention includes: a light source system, a measurement system and a data processing system.

[0024] Specifically, Figure 1 As shown, the light source system includes a tunable laser 1, a polarization controller 2 and an attenuator 3, the measurement system includes an optical fiber 4, an optical microcavity 5, a puncture needle 6, and the data processing system includes a photodetector 7, an oscilloscope 8 and a data acquisition card 9. The output end of the tunable laser 1 is connected to the input end of the polarization controller 2 through an optical fiber, and the polarization controller 2 is a mechanical polarization controller. The output end of the mechanical polarization controller is connected to the input end of the attenuator 3 through an optical fiber. The optical fiber 4 is connected to the output end of the attenuator 3 and the photodetector 7 respectively. The optical fiber 4 has two large-diameter ends and a small-diameter section. The two large-diameter ends are connected to the output end of the attenuator 3 and the photodetector 7 respectively, and the small-diameter section is spaced apart from the optical microcavity 5. The optical microcavity 5 is a microbubble cavity made of glass or other light-guiding materials. The middle part of the optical microcavity 5 has a circular protrusion. The small-diameter end of the optical fiber 4 is close to the microbubble cavity. One end of the optical microcavity 5 is closed, and the other end is connected to the puncture needle 6 through a hose 10, and the hose 10 is a Teflon tube. The output end of the photodetector 7 is electrically connected to the oscilloscope 8 and the data acquisition card 9 respectively.

[0025] In other embodiments, the photoelectric detector 7 may also be directly connected to a computer, and the measurement data may be directly displayed by the computer.

[0026] According to the optical tonometer of the embodiment of the present invention, the tunable laser 1 emits laser light, which enters the optical fiber 4 after being adjusted by the polarization controller 2 and the attenuator 3. Since the small diameter section of the optical fiber 4 is close to the microbubble cavity, the light field can be introduced and exported to the optical microcavity 5 through the optical fiber 4 through the evanescent field. The light in the microbubble cavity is totally reflected at the microcavity interface, generating a resonant mode of the whispering gallery mode (WGM). Within the boundary of the closed cavity, the light is always trapped inside the microbubble cavity to maintain a stable traveling wave transmission mode. The laser is input into the photodetector 7 through the optical fiber 4, and the photodetector 7 converts the optical signal into an electrical signal, and the output spectrum is displayed on the oscilloscope 7, and the pressure value is displayed through the calculation of the data acquisition card 8.

[0027] When the puncture needle 6 is not inserted into the front of the eyeball or the vitreous cavity of the eyeball, the output spectrum of the microbubble cavity is in a Lorentz linear distribution. When the puncture needle 6 is inserted into the front of the eyeball or the vitreous cavity of the eyeball, the change in intraocular pressure will cause the change in the gas column pressure in the Teflon tube, thereby deforming the microbubble cavity, causing the change in the microcavity resonance frequency in the microbubble cavity, and causing the movement of the center position of the output Lorentz spectrum line. By calculating the movement value of the center position of the output Lorentz spectrum line, accurate measurement of intraocular pressure can be achieved.

[0028] This embodiment does not impose any formal limitation on the shape, material, structure, etc. of the present invention. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0029] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0030] If the words "first", "second", etc. are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description. Unless otherwise stated, the above words have no special meaning.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical tonometer, characterized in that: include: A light source system, the light source system comprising a tunable laser, a polarization controller and an attenuator, the polarization controller and the attenuator being used to adjust the light emitted by the tunable laser; A data processing system, the data processing system comprising a photoelectric detector, an oscilloscope and a data acquisition card, the photoelectric detector being electrically connected to the oscilloscope and the data acquisition card respectively; A measurement system, the measurement system comprising an optical fiber, an optical microcavity, and a puncture needle, wherein the two ends of the optical fiber are respectively connected to the output end of the light source system and the photodetector, the optical microcavity is coupled to the optical fiber, one end of the optical microcavity is closed, and the other end is connected to the puncture needle; The optical microcavity is a light-guiding material; The optical microcavity is a microbubble cavity, and the middle part of the microbubble cavity has a circular protrusion; A hose is also provided, and two ends of the hose are respectively connected to the microbubble cavity and the puncture needle; The hose is a Teflon tube; The puncture needle is used to be inserted in front of the eyeball or the vitreous cavity of the eyeball. Changes in intraocular pressure will cause changes in the air column pressure in the Teflon tube, thereby deforming the microbubble cavity, causing changes in the resonance frequency of the microcavity in the microbubble cavity, and causing the center position of the output Lorentz spectrum line to move. By calculating the movement value of the center position of the output Lorentz spectrum line, accurate measurement of intraocular pressure can be achieved.

2. The optical tonometer according to claim 1, characterized in that: The two ends of the optical fiber are large-diameter ends, the middle part is a small-diameter section, and the small-diameter section is spaced apart from the optical microcavity.

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