Scanning device and optical coherence tomography system

Abstract

A scanning device and an optical coherence tomography system. The scanning device used in the optical coherence tomography system integrates a scanning lens group required by the coherence tomography system into a fundus imaging system, so that the coherence tomography system and the fundus imaging system can share the scanning lens group for focusing. The above-mentioned scanning device can shorten the response time of focusing and reduce the volume of the system. At the same time, an optical coherence tomography system including the above-mentioned scanning device is also disclosed.

Description

Technical Field

[0001] The present invention relates to a scanning device and an optical coherence tomography system, in particular to an optical coherence tomography system combined with an optical camera. Background Art

[0002] Optical Coherence Tomography (OCT) is an optical imaging technology that generates a tomographic image by causing two light beams to interfere with each other after being reflected by a reference arm and a sample arm respectively on a light detector.

[0003] Please refer to Figure 1 An optical coherence tomography system for obtaining fundus tomography images includes a scanning light source 11, a coupler 12, a reference light arm 13, a sampling light arm 14, and a spectrometer 15. The coupler 12 is optically coupled to the scanning light source 11, the reference light arm 13, the sampling light arm 14, and the spectrometer 15 via an optical fiber 121. The scanning light generated by the scanning light source 11 is divided into the reference light arm 13 and the sampling light arm 14 by the coupler 12. The reference light RL passing through the reference light arm 13 is output from a collimator 131, reflected by a reference reflector 132, and then returned to the collimator 131, and then returned to the coupler 12. The sampling light SL passing through the sampling light arm 14 is output from the collimator 141, and is incident on the fundus of an eyeball 300 of a subject after passing through a scanning reflector 142, a scanning lens 143, a beam splitter 144, and an objective lens 145. The reflected light of the fundus of the eyeball 300 returns to the collimator 141 via the same path, and then returns to the coupler 12. The spectrometer 15 detects the optical signal of the interference between the reference light RL and the sampling light SL for subsequent reconstruction processing to form a tomographic image of the fundus.

[0004] Please refer to Figure 1 In order to obtain the fundus image of the eyeball 300, the sampling optical arm 14 further includes a fundus imaging system 16, so that the operator can observe the fundus position of the subject and confirm the scanning position of the OCT. An illumination light reflected by the fundus of the eyeball 300 can be imaged on an image sensor 163 along the optical axis OA through the objective lens 145, the beam splitter 144, a focusing lens 161 and an imaging lens 162 to form a fundus image of the eyeball 300.

[0005] It is understandable that each subject's eyeball 300 may have different diopters, such as myopia or hyperopia. In order to obtain a better quality tomographic image, the position of the scanning lens 143 can be moved to compensate for the diopters of the eyeball. Similarly, in order to obtain a better quality fundus image, the position of the focusing lens 161 in the fundus imaging system 16 can be moved to compensate for the diopters of the eyeball. However, different focusing systems require their own corresponding control devices, which not only increases the focusing time and cost, but also makes it impossible to reduce the size of the optical coherent tomography system, thereby limiting its scope of application.

[0006] Therefore, providing an optical coherence tomography system that can focus quickly and is small in size is a goal that needs to be worked on at present. Summary of the invention

[0007] The present invention provides a scanning device and an optical coherence tomography system, which integrates a scanning lens group required by the coherence tomography system into a fundus imaging system, so that the coherence tomography system and the fundus imaging system can share the scanning lens group for focusing, thereby shortening the focusing response time and reducing the size of the system.

[0008] The scanning device of one embodiment of the present invention is used to form an optical coherent tomography system with a host, wherein the host outputs a sampling light. The scanning device includes a scanning reflector, a beam splitter, a scanning lens group, an objective lens, an illumination light source, an imaging lens group, and an image sensor. The scanning reflector is optically coupled to the host to deflect the sampling light so that the sampling light scans a fundus of an eyeball. The beam splitter is optically coupled to the scanning reflector to guide the sampling light to the eyeball. The scanning lens group is optically coupled to the beam splitter. The objective lens is coaxially arranged with the scanning lens group relative to an optical axis, so that the sampling light from the beam splitter passes through the scanning lens group and the objective lens in sequence and is incident on the fundus of the eyeball, and the sampling light reflected by the fundus returns to the host along a sampling optical path to generate a corresponding tomography image. The illumination light source is arranged off the optical axis to generate an illumination light, wherein the illumination light is irradiated to the fundus of the eyeball through the objective lens. The imaging lens group is optically coupled to the beam splitter. The image sensor is arranged on a light-emitting side of the imaging lens group, wherein the illumination light source, the objective lens, the scanning lens group, the imaging lens group and the image sensor constitute a fundus imaging system, and the optical coherence tomography system and the fundus imaging system share the scanning lens group, so that the illumination light reflected by the fundus of the eyeball is imaged to the image sensor via the objective lens, the scanning lens group, the beam splitter and the imaging lens group, and a corresponding fundus image is generated.

[0009] The optical coherence tomography system of another embodiment of the present invention includes a host and a scanning device. The host includes a scanning light source, a coupler and a spectrometer. The scanning light source is used to generate a scanning light. The coupler is optically coupled to the scanning light source so that the scanning light is divided into a reference light and a sampling light, wherein the reference light passing through a reference light path is reflected by a reference reflector and returns to the coupler along the reference light path. The spectrometer is optically coupled to the coupler. The scanning device includes a scanning reflector, a beam splitter, a scanning lens group, an objective lens, an illumination light source, an imaging lens group and an image sensor. The scanning reflector is optically coupled to the coupler to deflect the sampling light and make the sampling light scan the bottom of an eyeball. The beam splitter is optically coupled to the scanning reflector to guide the sampling light to the eyeball. The scanning lens group is optically coupled to the beam splitter. The objective lens is coaxially arranged with the scanning lens group relative to an optical axis, so that the sampling light from the beam splitter is incident on the fundus of the eyeball through the scanning lens group and the objective lens in sequence, and the sampling light reflected by the fundus returns to the coupler along a sampling optical path, so that the spectrometer receives the reference light reflected by the reference mirror and the sampling light reflected by the fundus, and generates a corresponding tomographic image. The illumination light source is arranged to deviate from the optical axis to generate an illumination light, wherein the illumination light is irradiated to the fundus through the objective lens. The imaging lens group is optically coupled with the beam splitter. The image sensor is arranged on a light-exiting side of the imaging lens group, wherein the illumination light source, the objective lens, the scanning lens group, the imaging lens group and the image sensor constitute a fundus imaging system, and the optical coherent tomography system and the fundus imaging system share the scanning lens group, so that the illumination light reflected by the fundus is imaged to the image sensor through the objective lens, the scanning lens group, the beam splitter and the imaging lens group, and generates a corresponding fundus image.

[0010] The following is a detailed description of the specific embodiments in conjunction with the attached drawings, so that the purpose, technical content, characteristics and effects of the present invention can be more easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. 1 is a schematic diagram showing a conventional optical coherence tomography system.

[0012] Figure 2 FIG. 4 is a schematic diagram showing an optical coherence tomography system according to an embodiment of the present invention.

[0013] Figure 3 FIG. 4 is a schematic diagram showing a focusing operation of an optical coherence tomography system according to an embodiment of the present invention.

[0014] 10 Host

[0015] 11 Scanning light source

[0016] 12 Coupler

[0017] 121 Fiber Optic

[0018] 122 Polarization Controller

[0019] 13 Reference light arm

[0020] 131 Collimator

[0021] 132 Reference reflector

[0022] 133 Aperture

[0023] 134 Dispersion Compensation Plate

[0024] 135 Lens

[0025] 14 Sampling optical arm

[0026] 141 Collimator

[0027] 142 Scanning mirror

[0028] 143 Scanning lens

[0029] 144 Spectrum Splitter

[0030] 145 Objective

[0031] 15. Spectrometer

[0032] 151 Diffraction Grating

[0033] 152 Lens

[0034] 153 Line Scan Camera

[0035] 16 Fundus Imaging System

[0036] 161 Focusing lens

[0037] 162 Imaging lens

[0038] 163 Image Sensor

[0039] 20 Scanning device

[0040] 201 Fundus Imaging System

[0041] 21 Collimator

[0042] 22 Scanning mirror

[0043] 23. Beam splitter

[0044] 24 Scanning lens group

[0045] 25 Objective lens

[0046] 26 Lighting source

[0047] 27 Imaging lens group

[0048] 28 Image Sensor

[0049] 29 Handheld housing

[0050] 300 Eyeball

[0051] A1, A2 arrows

[0052] IL Illumination

[0053] OA optical axis

[0054] RL Reference Light

[0055] SL Sampling Light DETAILED DESCRIPTION

[0056] The following will describe in detail various embodiments of the present invention, and will be illustrated with drawings. In addition to these detailed descriptions, the present invention can also be widely implemented in other embodiments, and any easy replacement, modification, and equivalent changes of the embodiments are included in the scope of the present invention and are subject to the scope of the patent application. In the description of the specification, many specific details are provided to enable the reader to have a more complete understanding of the present invention; however, the present invention may still be implemented on the premise of omitting some or all of the specific details. In addition, well-known steps or devices are not described in detail to avoid unnecessary limitations on the present invention. The same or similar devices in the drawings will be represented by the same or similar symbols. It should be noted that the drawings are for illustration only and do not represent the actual size or quantity of the devices. Some details may not be fully drawn to simplify the drawings.

[0057] Please refer to Figure 2 , an optical coherence tomography system of an embodiment of the present invention includes a host 10 and a scanning device 20. The host 10 includes a scanning light source 11, a coupler 12 and a spectrometer 15. The scanning light source 11 is used to generate a scanning light. For example, the scanning light source 11 can be a super luminescent diode (SLD). The coupler 12 is optically coupled to the scanning light source 11 so that the scanning light is divided into a reference light RL and a sampling light SL, and guided to a reference light arm 13 and a sampling light arm (i.e., the scanning device 20) respectively. For example, the coupler 12 is optically coupled to the scanning light source 11 by an optical fiber 121, and outputs the reference light RL and the sampling light SL to the reference light arm 13 and the sampling light arm (scanning device 20) respectively by the optical fiber 121.

[0058] In one embodiment, the reference light arm 13 includes at least a collimator 131 and a reference reflector 132. The collimator 131 is disposed at one end of the optical fiber 121, so that the reference light RL is output from the collimator 132, and travels along a reference light path to the reference reflector 132, and then reflects back to the collimator 131. It is understandable that the reference light arm 13 may include other suitable optical devices. For example, an aperture 133, a dispersion compensator (DC) 134 and a lens 135 may be disposed in the reference light path to stabilize the quality of the reference light RL. The reference light path refers to the light path that the reference light RL takes when it is output from the coupler 12, reflected by the reference reflector 132 and then returns to the coupler 12. The detailed structure of the reference light arm 13 is well known to relevant personnel in the field, so it will not be repeated here. In one embodiment, the host 10 may include a polarization controller 122 optically coupled to the coupler 12 to polarize the scanning light to the reference light arm 13 and the sampling light arm (scanning device 20).

[0059] The spectrometer 15 is optically coupled to the coupler 12. For example, the spectrometer 15 is optically coupled to the coupler 12 via an optical fiber 121. The spectrometer 15 is used to receive optical signals returned from the reference optical arm 13 and the sampling optical arm (scanning device 20). In one embodiment, the spectrometer 15 includes a diffraction grating 151, a lens 152, and a line scan camera 153 to detect optical signals of interference between the reference light RL and the sampling light SL returned from the reference optical arm 13 and the sampling optical arm (scanning device 20).

[0060] The scanning device 20 includes a scanning reflector 22, a beam splitter 23, a scanning lens group 24, an objective lens 25, an illumination light source 26, an imaging lens group 27, and an image sensor 28. In one embodiment, the scanning device 20 further includes an optical fiber 121 and a collimator 21. One end of the optical fiber 121 is optically coupled to the coupler 12 of the host 10. The collimator 21 is disposed at the other end of the optical fiber 121 and is optically coupled to the scanning reflector 22, so that the sampling light SL can be output from the collimator 21 to the scanning reflector 22. The scanning reflector 22 can deflect the path of the sampling light SL by rotating or other means, thereby changing the sampling light SL to irradiate different positions of the fundus of the eyeball 300. It can be understood that by sequentially changing the position where the sampling light SL irradiates the fundus, a specific area of ​​the fundus of the eyeball 300 can be completely scanned.

[0061] Continuing with the above description, the beam splitter 23 is optically coupled to the scanning mirror 22 to guide the sampling light SL to irradiate in the direction of the eyeball 300. The scanning lens group 24 is optically coupled to the beam splitter 23, and the objective lens 25 is coaxially arranged with the scanning lens group 24 relative to an optical axis OA, so that the sampling light SL from the beam splitter 23 passes through the scanning lens group 24 and the objective lens 25 in sequence and is incident on the fundus of the eyeball 300. The sampling light SL reflected by the fundus of the eyeball 300 then passes through the objective lens 25, the scanning lens group 24, the beam splitter 23 and the scanning mirror 22 in sequence to return to the collimator 21 and then to the coupler 12. In short, the sampling light path refers to the light path that the sampling light SL takes when it is output from the coupler 12, reflected by the fundus of the eyeball 300, and then returns to the coupler 12. It can be understood that the reference light RL reflected by the reference reflector 132 and the sampling light SL reflected by the fundus of the eyeball 300 return to the coupler 12 and are then output to the spectrometer 15. The spectrometer 15 can detect the optical signals of the interference between the reference light RL and the sampling light SL for subsequent reconstruction processing to form a tomographic image.

[0062] In addition, the scanning lens group 24, the objective lens 25, the illumination light source 26, the imaging lens group 27 and the image sensor 28 of the scanning device 20 constitute a fundus imaging system 201. The illumination light source 26 is arranged to deviate from the optical axis OA to generate an illumination light. The illumination light can be converged by the objective lens 25 and then irradiated to the fundus after passing through the pupil of the eyeball 300. For example, the illumination light source 26 can be a point light source, such as a light emitting diode (LED). In one embodiment, the illumination light generated by the illumination light source 26 is directly irradiated to the objective lens 25, so that devices such as a reflector or a relay lens can be omitted to reduce the size of the system.

[0063] Continuing the above description, the imaging lens group 27 is optically coupled to the beam splitter 23, and the image sensor 28 is disposed on a light exit side of the imaging lens group 27. According to this structure, the illumination light IL reflected by the fundus of the eyeball 300 is imaged to the image sensor 28 in sequence through the objective lens 25, the scanning lens group 24, the beam splitter 23 and the imaging lens group 27, and a corresponding fundus image is generated. It should be noted that Figure 2 The lenses shown, such as the objective lens 25, the scanning lens group 24, and the imaging lens group 27, are only examples for the convenience of description, and their optical characteristics should be designed according to actual needs.

[0064] in accordance with Figure 2In the structure shown, the scanning lens group 24 required by the coherent tomography system is integrated into the fundus imaging system 201. Therefore, the scanning lens group 24 can be moved along the optical axis OA to adjust the focal length to compensate for the different refractive powers of the eyeball 300, thereby obtaining a tomography image and a fundus image of better quality. In short, the coherent tomography system and the fundus imaging system 201 can share the scanning lens group 24 for focusing. Therefore, when the operator completes the focusing through the fundus imaging system 201, the coherent tomography system also completes the focusing. For example, please refer to Figure 3 When the subject's eyeball 300 has normal vision, the scanning lens assembly 24 is at a preset position, such as Figure 3 When the subject's eyeball 300 is hyperopic (+10D), the scanning lens group 24 can move along the optical axis OA in a direction away from the objective lens 25, as shown in the middle figure in FIG. Figure 3 In contrast, when the subject's eyeball 300 is myopic (-10D), the scanning lens group 24 can move along the optical axis OA toward the direction close to the objective lens 25, as shown in the arrow A1 direction in the upper figure. Figure 3 As shown in the direction of arrow A2 in the figure below.

[0065] In one embodiment, the process of adjusting the focal length only moves the scanning lens group 24, but the illumination light source 26 and the imaging lens group 27 are fixed, that is, the distance from the illumination light source 26 and the imaging lens group 27 to the objective lens 25 is fixed, which can simplify the optical design. In one embodiment, the distance from the illumination light source 26 to the objective lens 25 is less than or equal to the distance from the scanning lens group 24 to the objective lens 25. It should be noted that Figure 3 The embodiment shown is to move the scanning lens group 24 to adjust the focal length, but the present invention is not limited thereto. For example, the scanning lens group 24 may also adjust the focal length by changing the curvature.

[0066] According to the above structure, the optical coherent tomography system of the present invention only needs a set of control devices corresponding to the scanning lens group 24 to adjust the focal length, which not only simplifies the optical path design, but also saves a lot of hardware devices and costs. In addition, the response time for focusing can be effectively shortened and the volume of the system can be greatly reduced, so as to facilitate miniaturization and portability. For example, please refer to Figure 2 The scanning device 20 may include a handheld housing 29, and the scanning reflector 22, the beam splitter 23, the scanning lens group 24, the objective lens 25, the illumination light source 26, the imaging lens group 27 and the image sensor 28 are disposed in the handheld housing 29. The scanning device 20 is optically coupled to the host 10 by an optical fiber 121, so that the operator can operate the scanning device 20 by hand, which is very convenient for observing the fundus of subjects with limited mobility (such as bedridden patients), infants or animals.

[0067] In one embodiment, the scanning device 20 is optically and electrically coupled to the host 10 in a detachable manner. For example, the host 10 may include an optical fiber connection interface and an electrical connection interface, and the scanning device 20 includes an optical fiber plug and an electrical connection plug corresponding to the optical fiber connection interface and the electrical connection interface of the host 10, so that a single host 10 can be used to replace an appropriate scanning device 20 for different purposes or different subjects.

[0068] In summary, the scanning device and the optical coherence tomography system of the present invention integrate the scanning lens group required by the coherence tomography system into the fundus imaging system, so that the coherence tomography system and the fundus imaging system can share the scanning lens group and focus by adjusting the scanning lens group. This not only simplifies the design and reduces the cost, but also shortens the focusing response time and reduces the size of the system.

[0069] The embodiments described above are only for illustrating the technical ideas and features of the present invention, and their purpose is to enable relevant personnel in the field to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the patent scope of the present invention. That is, all equivalent changes or modifications made according to the spirit disclosed by the present invention should still be included in the patent scope of the present invention.

Claims

1. A scanning device, which together with a host constitutes an optical coherent tomography system, characterized in that: The host outputs a sampling light, and the scanning device includes: A scanning reflector, optically coupled to the host, to deflect the sampling light so that the sampling light scans a bottom of an eye of the eyeball; a beam splitter optically coupled to the scanning mirror for guiding the sampling light to the eyeball; a scanning lens assembly optically coupled to the beam splitter; an objective lens, which is coaxially arranged with the scanning lens group relative to an optical axis, so that the sampling light from the beam splitter passes through the scanning lens group and the objective lens in sequence and is incident on the fundus of the eyeball, and the sampling light reflected by the fundus returns to the host along a sampling optical path to generate a corresponding tomographic image; an illumination light source, which is arranged away from the optical axis and is used to generate an illumination light, wherein the illumination light is irradiated to the fundus of the eyeball through the objective lens; an imaging lens group optically coupled to the beam splitter; an image sensor disposed at a light-exiting side of the imaging lens group, wherein the illumination light source, the objective lens, the scanning lens group, the imaging lens group and the image sensor constitute a fundus imaging system, and the optical coherence tomography system and the fundus imaging system share the scanning lens group, so that the illumination light reflected by the fundus of the eyeball is imaged to the image sensor via the objective lens, the scanning lens group, the beam splitter and the imaging lens group, and a corresponding fundus image is generated; as well as A handheld housing, wherein the scanning reflector, the beam splitter, the scanning lens group, the objective lens, the illumination light source, the imaging lens group and the image sensor are disposed in the handheld housing, and the scanning device is optically coupled to the host by an optical fiber; The imaging lens group is located between the beam splitter and the image sensor.

2. The scanning device according to claim 1, characterized in that The scanning lens group moves along the optical axis or changes the curvature to adjust the focal length.

3. The scanning device according to claim 1, characterized in that: Also includes: A collimator is optically coupled to the scanning mirror.

4. The scanning device according to claim 1, characterized in that: The illumination light source is a point light source.

5. The scanning device according to claim 1, characterized in that: The distance from the illumination light source to the objective lens is less than or equal to the distance from the scanning lens group to the objective lens.

6. The scanning device according to claim 1, characterized in that: The distance from the illumination light source to the objective lens is fixed.

7. The scanning device according to claim 1, characterized in that: The distance between the imaging lens group and the objective lens is fixed.

8. An optical coherence tomography system, characterized in that: Include: A host computer, comprising: A scanning light source for generating a scanning light; a coupler optically coupled to the scanning light source to separate the scanning light into a reference light and a sampling light, wherein the reference light traveling through a reference light path is reflected by a reference reflector and returns to the coupler along the reference light path; and a spectrometer optically coupled to the coupler; A scanning device comprising: a scanning mirror optically coupled to the coupler to deflect the sampling light and make the sampling light scan an eye bottom of an eye ball; a beam splitter optically coupled to the scanning mirror for guiding the sampling light to the eyeball; a scanning lens assembly optically coupled to the beam splitter; an objective lens, which is coaxially arranged with the scanning lens group relative to an optical axis, so that the sampling light from the beam splitter passes through the scanning lens group and the objective lens in sequence and is incident on the fundus of the eyeball, and the sampling light reflected by the fundus returns to the coupler along a sampling optical path, so that the spectrometer receives the reference light reflected by the reference reflector and the sampling light reflected by the fundus, and generates a corresponding tomographic image; an illumination light source, which is arranged away from the optical axis and is used to generate an illumination light, wherein the illumination light is irradiated to the fundus through the objective lens; an imaging lens group optically coupled to the beam splitter; an image sensor disposed at a light-exiting side of the imaging lens group, wherein the illumination light source, the objective lens, the scanning lens group, the imaging lens group and the image sensor constitute a fundus imaging system, and the optical coherence tomography system and the fundus imaging system share the scanning lens group, so that the illumination light reflected by the fundus is imaged to the image sensor via the objective lens, the scanning lens group, the beam splitter and the imaging lens group, and a corresponding fundus image is generated; as well as A handheld housing, wherein the scanning reflector, the beam splitter, the scanning lens group, the objective lens, the illumination light source, the imaging lens group and the image sensor are disposed in the handheld housing, and the scanning reflector is optically coupled to the coupler by an optical fiber; The imaging lens group is located between the beam splitter and the image sensor.

9. The optical coherence tomography system according to claim 8, wherein: The scanning light source includes a superluminescent diode.

10. The optical coherence tomography system according to claim 8, wherein: The spectrometer includes a diffraction grating and a linear scanning camera.

11. The optical coherence tomography system according to claim 8, wherein: The host also includes: A polarization controller is optically coupled to the coupler to polarize the reference light and the sampling light.

12. The optical coherence tomography system according to claim 8, wherein: The scanning lens group moves along the optical axis or changes the curvature to adjust the focal length.

13. The optical coherence tomography system according to claim 8, wherein: The scanning device further comprises: A collimator is optically coupled with the scanning mirror, wherein the collimator and the host are respectively arranged at two ends of the optical fiber.

14. The optical coherence tomography system according to claim 8, wherein: The scanning device is optically and electrically coupled to the host in a detachable manner.

15. The optical coherence tomography system according to claim 8, wherein: The illumination light source is a point light source.

16. The optical coherence tomography system according to claim 8, wherein: The distance from the illumination light source to the objective lens is less than or equal to the distance from the scanning lens group to the objective lens.

17. The optical coherence tomography system according to claim 8, wherein: The distance from the illumination light source to the objective lens is fixed.

18. The optical coherence tomography system according to claim 8, wherein: The distance between the imaging lens group and the objective lens is fixed.

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