OCT (Optical Coherence Tomography) handheld probe for fundus screening

Abstract

The invention provides an OCT handheld probe for fundus screening. The OCT handheld probe comprises a shell, an EMES galvanometer, a dichroscope, an eye objective lens, a concave lens, a reflector and a visible light source. The EMES galvanometer, the dichroscope and the eye objective lens form a short-optical-path OCT scanning light path based on the MEMS galvanometer, and the short-optical-path OCT scanning light path serves as an OCT scanning unit to achieve fundus imaging; a red light reflection coaxial illumination light path formed by the eye objective lens, the concave lens and the illumination light source is used as a transverse positioning unit to realize the positioning of the probe in the direction parallel to the face plane of the detected object, and a red light reflection coaxial illumination light path formed by the visible light source, the reflector, the eye objective lens and the concave lens is used as a longitudinal positioning unit to realize the positioning of the probe in the direction parallel to the face plane of the detected object. Therefore, the probe can be positioned in the direction perpendicular to the face plane of the detected object. In a volume range suitable for being held by a single hand, high spatial resolution and a large scanning range can be realized, and the pupil position and the light entrance pupil state can be directly observed in the examination process.

Description

Technical Field

[0001] The present disclosure belongs to the field of medical imaging diagnosis, and particularly proposes a handheld optical probe structure for performing optical coherence tomography (OCT) three-dimensional scanning of the fundus. The structure conforms to an ergonomic holding method and can perform large-scale OCT imaging of the fundus. Background Art

[0002] The incidence of neonatal ophthalmological diseases is about 0.2%, and there is currently no effective means of examination. This leads to a delay in the course of the disease and causes irreversible visual damage to the child. Early detection of neonatal ophthalmological diseases has always been a very popular project in the industry.

[0003] Ophthalmological examinations are highly dependent on instruments and equipment. Currently, fundus photography of newborns has been realized, but it can only examine flat images, and nearly 50% of infants have lesions in deep tissue structures, which cannot be effectively diagnosed using fundus photography.

[0004] OCT is a technology that uses infrared light to scan the surface of human tissue and can perform three-dimensional imaging of tissue structures several millimeters below the tissue surface. Ophthalmic OCT is already the gold standard for ophthalmic examinations, and its authority and comprehensiveness are far superior to fundus cameras. However, ordinary ophthalmic OCT equipment can only be used for adult or pediatric patients who are seated and have good cooperation, and cannot be used on newborns. When performing fundus OCT examinations on newborns, the newborns lie in a supine position, and the doctor needs to hold an optical probe to scan their fundus. Since newborns are not cooperative, it often takes a long time to capture images, and the handheld probe must be light and easy to operate. On the other hand, the intraocular field of view of ordinary fundus cameras is 45°, covering the core fundus part from the macula to the optic disc. Fundus OCT examinations of newborns also need to be able to achieve this scanning range.

[0005] The neonatal fundus OCT optical probe needs to achieve a large scanning angle and high imaging resolution within a palm-sized volume. It also needs to minimize the number of optical components to reduce weight. It also needs to be easy to hold and meet the ergonomic requirements of the patient and doctor's body posture during neonatal fundus screening, which poses a challenge to the optical structure design of the probe.

[0006] Currently, research on fundus OCT imaging of newborns is extremely limited. A research team from Duke University proposed a handheld optical probe implementation scheme in the literature [1] (Francesco LaRocca, Derek Nankivil, Theodore DuBose, Cynthia A. Thoth, Sina Farsiu and Joseph A. Izatt, “In vivo celluar-resolution retinal imaging in infants and children using an ultracompact handheld probe,” Nature Phothonics, vol. 10, pp. 580-584, 2016). This scheme can only achieve a 7° field of view of the fundus in one scan, and doctors cannot see the position of the newborn's pupil during the examination and can only guess based on the OCT image, which makes image capture difficult. A research team from the Massachusetts Institute of Technology demonstrated a handheld OCT probe implementation for adults in the literature [2] (Chen D. Lu, Martin F. Kraus, Benjamin Potsaid, Jonathan J. Liu, Woojhon Choi, Vijaysekhar Jayaraman, Alex E. Cable, Joachim Hornegger, Jay S. Duker, and James Fujimoto, "Handheld ultrahighspeed swept source optical coherence tomogaraphy instrument using a MEMS scanning mirror," Biomedical Optics Express, vol. 5, no. 1, pp. 293-311, 2014). This solution has a large probe size and weight, and requires the patient to sit and look at the probe, which is not suitable for the special needs of fundus screening of newborns. Summary of the invention

[0007] The present disclosure aims to solve one of the technical problems existing in the prior art at least to some extent.

[0008] To this end, the present disclosure provides an OCT handheld probe for fundus screening, which can provide OCT optical scanning capabilities with high spatial resolution and a large scanning range within a volume range suitable for one-handed holding, and can directly observe the pupil position and the state of light entering the pupil during the inspection, greatly facilitating the inspection process.

[0009] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0010] The present disclosure provides an OCT handheld probe for fundus screening, comprising a housing, an EMES galvanometer, a dichroic mirror, an eyepiece objective lens, a concave lens, a reflector, and a visible light source;

[0011] The OCT scanning unit is composed of the EMES galvanometer, the dichroic mirror and the eyepiece objective lens, wherein the EMES galvanometer and the dichroic mirror are located in the housing, and the eyepiece objective lens is located on the side wall of the housing and is arranged facing the object to be inspected; the EMES galvanometer is used to scan the OCT irradiation light input through the optical fiber, the dichroic mirror is used to transmit and reflect the scanning light beam formed by the EMES galvanometer, and the eyepiece objective lens is used to make the reflected light beam formed by the dichroic mirror incident on the pupil of the object to be inspected and focus it on the retina, thereby realizing fundus imaging;

[0012] The eyepiece objective lens, the concave lens and the illumination light source constitute a lateral positioning unit; the concave lens is located on the side wall of the housing and is arranged facing the inspection object, the illumination light source is arranged near the eyepiece objective lens and is used to illuminate the human eye, and the inspection object realizes the positioning of the probe in a direction parallel to the face plane of the inspection object according to whether the inspection object can observe the virtual image formed by the light scattered from the iris and pupil after passing through the concave lens from the eyepiece objective lens from one side of the concave lens;

[0013] The visible light source, the reflector, the eyepiece objective lens and the concave lens constitute a longitudinal positioning unit. The reflector is arranged in the housing and is located below the concave lens. The visible light beam reflected by the reflector passes through the eyepiece objective lens and is focused on the focal plane of the eyepiece objective lens. The inspection object realizes the positioning of the probe in a direction perpendicular to the face plane of the inspection object based on the red light reflection intensity from the fundus observed from one side of the concave lens.

[0014] In some embodiments, the housing is divided into a hand-holding area and an inspection area, and the eyepiece objective lens and the concave lens are located on opposite side walls of the housing in the inspection area.

[0015] In some embodiments, the EMES galvanometer is a one-dimensional or two-dimensional EMES galvanometer.

[0016] In some embodiments, the dichroic mirror is a dichroic mirror that can transmit visible light and reflect the OCT illumination light.

[0017] In some embodiments, the OCT scanning unit also includes a collimating lens and a focusing lens arranged between the optical fiber and the MEMS galvanometer, the output end of the optical fiber is located at the focus of the collimating lens, the mirror surface of the MEMS galvanometer is located within the range of the focusing light beam generated by the focusing lens, and the mirror surface diameter of the MEMS galvanometer should be larger than the cross-sectional diameter of the focusing light beam at the position of the mirror surface.

[0018] In some embodiments, the OCT scanning unit further includes a lens disposed between the MEMS galvanometer and the dichroic mirror, the focus of the lens is located at the mirror surface of the MEMS galvanometer, and the distance between the lens and the eyepiece objective lens is the focal length of the eyepiece objective lens.

[0019] In some embodiments, when the eyepiece objective is located directly above the pupil, the subject being inspected can observe the virtual image from one side of the concave lens, thereby achieving positioning of the probe in a direction parallel to the face plane of the subject being inspected.

[0020] In some embodiments, the lighting source is an LED lamp.

[0021] In some embodiments, the visible light beam generated by the visible light source is incident on the reflector in a manner of approximately parallel light and is focused on the focal plane of the eyepiece objective lens, and the diameter of the light spot focused on the focal plane of the eyepiece objective lens is close to the pupil diameter of the detected object.

[0022] In some embodiments, when the focal plane of the eyepiece objective is coplanar with the pupil of the inspected object, the red light reflection intensity observed by the inspected object from the side of the concave lens reaches a maximum, thereby achieving the positioning of the probe in a direction perpendicular to the facial plane of the inspected object.

[0023] Features and beneficial effects of the present disclosure:

[0024] The present disclosure provides an OCT handheld probe for fundus screening, which integrates a short optical path OCT optical path based on two-dimensional MEMS galvanometer scanning, a pupil direct view optical path, and a red light reflection coaxial illumination optical path into a common path optical structure. By directly observing the pupil position, the doctor can adjust the probe position and posture to track the pupil position; by observing the red light reflection of the fundus to determine the working distance, the fundus OCT image can be efficiently collected under the conditions of accurate pupil position and working distance. The probe has the advantages of small size, light weight, easy to hold, high spatial resolution and large scanning range, and is particularly suitable for the use scenario of fundus OCT image collection in newborns. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of an application scenario of an embodiment of the present disclosure applied to neonatal fundus OCT image acquisition;

[0026] Figure 2 is a schematic diagram of the optical path structure of an OCT handheld probe for fundus screening provided by an embodiment of the present disclosure;

[0027] Figure 3 yes Figure 2 The schematic diagram of the compact OCT scanning optical path based on the two-dimensional MEMS scanning galvanometer;

[0028] Figure 4 yes Figure 2 Schematic diagram of the mid-pupillary direct vision optical path;

[0029] Figure 5 yes Figure 2 Schematic diagram of the light path for red reflected coaxial illumination.

[0030] Reference numerals:

[0031] 01. Optical fiber, 02. Collimating lens, 03. Focusing lens, 04. EMES galvanometer, 05. Lens, 06. Dichroic mirror, 07. Eyepiece objective lens, 08. Concave lens, 09. Illumination fiber bundle, 10. Reflector, 11. Pupil, 12. Retina, 13. Illumination light source, 14. Housing, A. Hand-held area, B. Inspection area. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] On the contrary, the present application covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present application as defined by the claims. Further, in order to make the public have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. Those skilled in the art can fully understand the present application without the description of these details.

[0034] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the restrictive conditions that can be implemented in this application, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that can be produced by this application and the purposes that can be achieved, should still fall within the scope of the technical content disclosed in this application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of narration, and are not used to limit the scope of the implementation of this application. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of this application without substantial change in the technical content.

[0035] For the convenience of description, in this application, the direction parallel to the facial plane of the inspected object is defined as the horizontal direction, and the direction perpendicular to the facial plane of the inspected object is defined as the vertical direction.

[0036] The application scenario of an OCT handheld probe provided in the present disclosure for fundus screening of newborns is as follows: Figure 1 As shown, when the newborn is undergoing fundus examination, the body is in a supine position with the eyes facing upward. The examinee I (such as a doctor) holds the OCT handheld probe of the embodiment of the present disclosure and successively performs OCT scanning examinations on the two eyes of the newborn, i.e. the examinee II. One end of the probe is connected to the OCT imaging system through optical fiber and cable. The OCT imaging system can be spectral domain OCT (SD-OCT) or swept source OCT (SS-OCT), and its operating wavelength can be 1050nm or 850nm. The specific implementation of the OCT imaging system does not fall within the protection scope of the present disclosure.

[0037] The probe of this embodiment is provided with an eye-viewing lens on the side facing the newborn, and a concave lens is provided on the side facing the doctor and located above the eye-viewing lens. The doctor can observe the pupil of the newborn through the concave lens. When the pupil appears in the center of the concave lens, it means that the transverse positioning of the probe is correct. The probe can move up and down. When the up and down positions are appropriate, the longitudinal positioning unit in the probe will irradiate light into the fundus through the pupil. The concave lens can observe the red-orange scattered light from the fundus, indicating that the working distance of the probe is correct. At this time, the OCT optical path can scan the fundus through the pupil, thereby obtaining a two-dimensional fundus profile OCT image or a three-dimensional stereoscopic OCT image of the fundus.

[0038] Specifically, see Figure 1 , Figure 2The OCT handheld probe provided by the embodiment of the present disclosure includes a housing 14, an EMES galvanometer 04, a dichroic mirror 06, an eyepiece objective lens 07, a concave lens 08, a reflector 10, an illumination light source 13 and a visible light source; wherein,

[0039] The housing 14 is divided into a hand-holding area A and an inspection area B;

[0040] The EMES galvanometer 04, the dichroic mirror 06 and the eyepiece objective lens 07 constitute an OCT scanning unit. The EMES galvanometer 04 and the dichroic mirror 06 are located in the housing 14. The eyepiece objective lens 07 is located on the side wall of the housing 14 in the inspection area B and is arranged facing the inspected object II. The EMES galvanometer 04 is used to scan the OCT irradiation light input by the OCT imaging system through the optical fiber 01. The OCT irradiation light is OCT infrared light. The dichroic mirror 06 is used to transmit and reflect the scanning light beam formed by the EMES galvanometer 04. The eyepiece objective lens 07 is used to make the reflected light beam formed by the dichroic mirror 06 incident on the pupil 11 and focus on the retina 12, thereby realizing fundus profile imaging or three-dimensional stereo imaging.

[0041] The eyepiece objective lens 07, the concave lens 08 and the illumination light source 13 constitute a lateral positioning unit; the concave lens 08 is located on the side wall of the housing 14 of the inspection area B and is arranged facing the inspection object I, and the illumination light source 13 is arranged near the eyepiece objective lens 07 for illuminating the human eye. The virtual image formed by the light scattered from the iris and the pupil 11 by the eyepiece objective lens 07 and passing through the concave lens 08 can be observed from the side of the concave lens 08, so as to realize the positioning of the probe in the direction parallel to the face plane of the inspection object II, that is, in the lateral direction;

[0042] The visible light source, the reflector 10, the eyepiece objective lens 07 and the concave lens 08 constitute a longitudinal positioning unit. The reflector 10 is arranged in the housing 14 and is located below the concave lens 08. The visible light source reflected by the reflector 10 passes through the eyepiece objective lens 07 and is focused on the focal plane of the eyepiece objective lens 07. According to the intensity of the red light reflection from the fundus observed from the side of the concave lens 08, the height of the eyepiece objective lens 07 is positioned, thereby realizing the positioning of the probe in the direction perpendicular to the facial plane of the inspected object II, that is, in the longitudinal direction.

[0043] Furthermore, in the handheld probe of this embodiment, a short optical path OCT scanning optical path based on a two-dimensional MEMS galvanometer is formed in the OCT scanning unit, a pupil direct view optical path is formed in the lateral positioning unit, and a red light reflection coaxial illumination optical path is formed in the longitudinal positioning unit, so that the OCT scanning optical path, the pupil direct view optical path and the red light reflection coaxial illumination optical path are integrated into a common-path optical structure.

[0044] Figure 2The optical path structure diagram of the handheld probe of the embodiment of the present disclosure. The optical path consists of three parts. The first part is the OCT scanning optical path. The infrared light irradiated by OCT is input by the OCT imaging system, input into the optical path of the handheld optical probe through the optical fiber 01, and incident on the MEMS galvanometer 04 through the collimating lens 02 and the focusing lens 03. The MEMS galvanometer 04 can realize the scanning of the OCT irradiation beam. A one-dimensional or two-dimensional MEMS galvanometer can be used to realize the one-dimensional or two-dimensional scanning of the OCT irradiation beam. The light reflected by the MEMS galvanometer 04 is irradiated onto the lens 05. The front focus of the lens 05 is just located at the MEMS array mirror 04. In this way, the light beams in different scanning directions can be output at parallel angles after passing through the lens 05. The output scanning beam is reflected by a dichroic mirror 06. The function of the dichroic mirror 06 is: it can realize transmission for visible light with a wavelength of 400nm-700nm, and it can realize reflection for OCT infrared light with a wavelength of 850nm or 1050nm. The light reflected by the dichroic mirror 06 is incident on the pupil 11 of the inspected object II after passing through the eyepiece lens 07, and is focused on the retina 12 of the inspected object II after passing through the optical system of the eye. When the MEMS galvanometer 04 scans, the light spot focused on the retina 12 also follows the scanning, so that fundus profile imaging or three-dimensional stereoscopic imaging can be achieved. The second part of the optical path is the pupil direct optical path, preferably using one or more LED lamps as the illumination light source 13 to illuminate the human eye, and the light scattered from the iris and pupil 11 passes through the eyepiece lens 07 and the concave lens 08 in turn to form a virtual image on the concave lens 08, and the virtual image can be directly observed by the inspected object I from the side of the concave lens 08 facing the inspected object I. When the eyepiece lens 07 on the probe is directly above the pupil 11, the virtual image of the pupil 11 can be seen, so that the relative distance between the eyepiece lens 07 and the pupil 11 can be positioned in the direction parallel to the plane of the newborn's face, thereby lateral positioning of the probe. The third part of the optical path is the red light reflection coaxial illumination optical path. Visible light is incident on a reflector 10 located below the concave lens 08 by the illumination fiber bundle 09 in a manner of approximately parallel light (so that the image of the reflector 10 can be formed at the pupil 11 in a small volume and then incident on the fundus). The light reflected by the reflector 10 is focused onto the focal plane of the eyepiece objective lens 07 after passing through the eyepiece objective lens 07. The focal plane of the eyepiece objective lens 07 is coplanar with the pupil 11 in this embodiment. Therefore, when the height of the eyepiece objective lens 07 is adjusted to a height where its focal plane is exactly at the height of the pupil 11, the visible light beam reflected by the reflector 10 can pass through the pupil 11 with maximum efficiency to illuminate the entire fundus. After diffuse reflection by the fundus, the illumination light is emitted through the pupil 11 again. Since the fundus has a strong reflection of red-orange light, the red light reflection from the fundus can be seen from the concave lens 08 at this time.When the red light reflection is strong, it indicates that the eyepiece objective lens 07 has been accurately positioned in the longitudinal direction, thereby realizing the longitudinal positioning of the probe. At this time, scanning beams at various angles from the OCT scanning light path can pass through the pupil 11, thereby enabling OCT scanning of the fundus.

[0045] Figure 3 yes Figure 2 The schematic diagram of the short optical path OCT scanning optical path based on the two-dimensional MEMS scanning galvanometer is shown in the figure. Optical fiber 01 is a single-mode optical fiber, and its output divergence angle is α. In a specific embodiment, optical fiber 01 is HI1060 optical fiber, the central wavelength of the OCT scanning light is 1050nm, and the output divergence angle is α=8°. The core of the output end of optical fiber 01 needs to be placed at the focus of the collimating lens 02. The light beam becomes a parallel light beam after passing through the collimating lens 02. If the focal length of the collimating lens 02 is f1, the diameter of the collimated parallel light beam is f1α. In this embodiment, f1 is 28mm, and the diameter of the collimated light beam is 4mm. The focusing lens 03 is located after the collimating lens 02 to focus the parallel light. The focal length of the focusing lens 03 is f2. The focal length f2 should take a larger value in this application so that the focal position of the focusing lens 03 is far away from the focusing lens 03. In this real-time example, f2 is taken as 10cm. The mirror surface of the MEMS galvanometer 04 is located within the range of the focused light beam of the focusing lens 03. In this embodiment, the mirror surface of the MEMS galvanometer 04 is located 5 cm behind the focusing lens 03. The cross-sectional diameter of the light beam here is 2 mm. The diameter of the mirror surface of the MEMS galvanometer 04 should be larger than the cross-sectional diameter of the light beam. In this embodiment, the diameter of the mirror surface of the MEMS galvanometer 04 is 2.4 mm. The scanning angle of the MEMS galvanometer 04 is ±β, and its output scanning angle is ±2β. In this embodiment, β is selected as 5°, and the MEMS galvanometer 04 can scan within the range of ±10°. Under the scanning action of the MEMS galvanometer 04, the focus of the focused light beam realizes a two-dimensional scan on the spherical surface. Figure 3The dotted line in is the intersection of this sphere with the plane where the paper is located. A lens 05 is placed after the MEMS galvanometer 04. The placement range of the lens 05 needs to be within the projection range of the spherical surface of the scanning focus part on the optical axis. In addition, the focus of the lens 05 needs to be exactly above the mirror position of the MEMS galvanometer 04. The focal length of the lens 05 is f3. In this embodiment, f3 is 5cm, and the distance between the lens 05 and the mirror surface of the MEMS galvanometer 04 is also 5cm. The central light of the scanning light beam with different scanning angles will continue to move forward in a direction parallel to the optical axis after passing through the lens 05. Since the focus point is located at the lens 05, after passing through the lens 05, the scanning optical fiber of different angles is approximately emitted from the plane where the lens 05 is located. The focal length of the eyepiece objective lens 07 is f4. The present application requires that the distance between the eyepiece objective lens 07 and the lens 05 (specifically, the distance between the front focus of the eyepiece objective lens 07 and the rear focus of the lens 05 on the main optical axis) is the focal length f4 of the eyepiece objective lens 07. At this time, the scanning beams of different angles passing through the lens 05 are incident from the front focal plane of the eyepiece lens 07 in a point light source manner with the central light ray parallel to the optical axis, so each scanning beam after output is approximately a collimated parallel beam, and its central light ray will be focused on the rear focus of the eyepiece lens 07. If the pupil 11 is located at the rear focus of the eyepiece lens 07 at this time, the OCT scanning of the fundus can be achieved. The magnification of the entrance pupil scanning angle is f3 / f4. In this embodiment, the focal length of the eyepiece lens 07 is 3 cm, and the magnification of the entrance pupil scanning angle is 1.67. The entrance pupil scanning angle is ±16.7°, and the corresponding intraocular field of view angle is about 50°, which can cover the core retina part from the macula to the optic disc.

[0046] Figure 4 Given Figure 2 The principle diagram of the pupil direct view optical path is defined as the pupilloscope, which is composed of the eyepiece objective lens 07 and the concave lens 08. Under ideal working conditions, the pupil 11 should be located on the focal plane a of the eyepiece objective lens 07, and then after passing through the eyepiece objective lens 07, the image is formed at infinity. The concave lens 08 diverges the parallel light rays of various angles from infinity, presenting a virtual image at its focal plane b. If the pupil 11 is not on the focal plane of the eyepiece objective lens 07, the pupilloscope can still form an image. When the subject I can observe the pupil 11 through the pupilloscope, it means that the probe is correctly positioned in a plane parallel to the newborn's face.

[0047] Figure 5 Given Figure 2The schematic diagram of the red light reflection coaxial illumination optical path, the light output from the illumination fiber bundle 09 can be regarded as parallel light beams with different angles, and each parallel light beam is focused on the focal plane of the eyepiece objective 07 after passing through the reflector 10. If the numerical aperture of the illumination fiber bundle 09 is NA, the diameter of the light spot at the focus is 2NAf4, and this diameter can be made close to the pupil diameter of the newborn through parameter optimization. When this light spot is exactly located at the pupil 11, it can be completely incident on the fundus of the newborn, so that the fundus shows a strong red light reflection, indicating that the probe is accurately positioned at the height position. At this time, the OCT scanning angle light beams can be incident on the pupil. In this embodiment, NA is 0.035, corresponding to a focused light spot diameter of 2.1mm.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0049] Although embodiments of the present disclosure have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. An OCT handheld probe for fundus screening, characterized in that: It includes a housing, an EMES galvanometer, a dichroic mirror, an eyepiece lens, a concave lens, a reflector and a visible light source; The OCT scanning unit is composed of the EMES galvanometer, the dichroic mirror and the eyepiece objective lens, wherein the EMES galvanometer and the dichroic mirror are located in the housing, and the eyepiece objective lens is located on the side wall of the housing and is arranged facing the object to be inspected; the EMES galvanometer is used to scan the OCT irradiation light input through the optical fiber, the dichroic mirror is used to transmit and reflect the scanning light beam formed by the EMES galvanometer, and the eyepiece objective lens is used to make the reflected light beam formed by the dichroic mirror incident on the pupil of the object to be inspected and focus it on the retina, thereby realizing fundus imaging; The eyepiece objective lens, the concave lens and the illumination light source constitute a lateral positioning unit; the concave lens is located on the side wall of the housing and is arranged facing the inspection object, the illumination light source is arranged near the eyepiece objective lens and is used to illuminate the human eye, and the inspection object realizes the positioning of the probe in a direction parallel to the face plane of the inspection object according to whether the inspection object can observe the virtual image formed by the light scattered from the iris and pupil after passing through the concave lens from the eyepiece objective lens from one side of the concave lens; The visible light source, the reflector, the eyepiece objective lens and the concave lens constitute a longitudinal positioning unit. The reflector is arranged in the housing and is located below the concave lens. The visible light beam reflected by the reflector passes through the eyepiece objective lens and is focused on the focal plane of the eyepiece objective lens. The inspection object realizes the positioning of the probe in a direction perpendicular to the face plane of the inspection object based on the red light reflection intensity from the fundus observed from one side of the concave lens.

2. The OCT handheld probe according to claim 1, characterized in that: The shell is divided into a hand-holding area and an inspection area, and the eyepiece objective lens and the concave lens are located on the side walls of the shell that are oppositely arranged in the inspection area.

3. The OCT handheld probe according to claim 1, characterized in that: The EMES galvanometer is a one-dimensional or two-dimensional EMES galvanometer.

4. The OCT handheld probe according to claim 1, characterized in that: The dichroic mirror is a dichroic mirror that can transmit visible light and reflect the OCT irradiation light.

5. The OCT handheld probe according to claim 1, characterized in that: The OCT scanning unit also includes a collimating lens and a focusing lens arranged between the optical fiber and the MEMS galvanometer. The output end of the optical fiber is located at the focus of the collimating lens. The mirror surface of the MEMS galvanometer is located within the range of the focusing light beam generated by the focusing lens, and the mirror surface diameter of the MEMS galvanometer should be larger than the cross-sectional diameter of the focusing light beam at the position of the mirror surface.

6. The OCT handheld probe according to claim 1, characterized in that: The OCT scanning unit further includes a lens arranged between the MEMS galvanometer and the dichroic mirror, the focus of the lens is located at the mirror surface of the MEMS galvanometer, and the distance between the lens and the eyepiece objective lens is the focal length of the eyepiece objective lens.

7. The OCT handheld probe according to claim 1, characterized in that: When the eyepiece objective is located directly above the pupil, the inspected subject can observe the virtual image from one side of the concave lens, thereby realizing the positioning of the probe in a direction parallel to the face plane of the inspected subject.

8. The OCT handheld probe according to claim 1, characterized in that: The lighting source is an LED lamp.

9. The OCT handheld probe according to claim 1, characterized in that: The visible light beam generated by the visible light source is incident on the reflector in a manner of approximately parallel light and is focused on the focal plane of the eyepiece objective lens. The diameter of the light spot focused on the focal plane of the eyepiece objective lens is close to the pupil diameter of the detected object.

10. The OCT handheld probe according to claim 1, characterized in that: When the focal plane of the eyepiece objective lens is coplanar with the pupil of the inspected object, the red light reflection intensity observed by the inspected object from the side of the concave lens reaches a maximum, thereby realizing the positioning of the probe in a direction perpendicular to the face plane of the inspected object.

Images