Crack light path generation system based on blowing type non-contact tonometer

Abstract

The invention belongs to the technical field of ophthalmology clinical medical treatment, and particularly discloses a crack light path generation system based on a blowing type non-contact tonometer, the crack light path generation system comprises a main crack light path system and a make-up crack light path system, a main crack light path and a make-up crack light path are synthesized into a conjugate light path through a flat spectroscope, and the conjugate light path is generated through a front crack light path incidence mode. Light intensity uniformity in the length direction of a crack light spot is achieved, the problems that an oblique double-crack light path is large in design and structure difficulty, and the light intensity of an imaging light spot and the width of a crack are not uniform are solved, meanwhile, on the basis of front incidence imaging, the view field range of 18 mm can be achieved, and the imaging precision is improved. And imaging and further biomechanical analysis of the whole region of the angular sclera are facilitated.

Description

Technical Field

[0001] The present invention relates to the field of ophthalmic clinical medical technology, and more specifically, to intraocular pressure measurement and biomechanical dynamic analysis based on corneal thickness calibration, and in particular to a slit optical path generation system based on non-contact intraocular pressure. Background Art

[0002] By combining air-puff non-contact tonometer with slit imaging technology, we can simultaneously obtain extraocular pressure values and analyze corneal and scleral biomechanics, including tomographic images of the corneal area indented by the air-puff pressure. This allows us to determine corneal thickness and correct intraocular pressure.

[0003] In the biomechanical analysis part of the existing technology, in order to solve the interference problem between the nozzle and the slit structure, the slit light path of OCULUSCorvis ST is spliced with symmetrical slit light spots on both sides. The two slit light beams are spliced into a slit light spot with a field of view of 9mm at the imaging point of the system. This technology has very high structural requirements and requires the two slit light paths to be designed to be completely symmetrical to reduce the position error of the light spot splicing. The light path also needs to avoid being blocked by other mechanical structures of the system. The size of the spliced field of view is also limited by the angle and the obstruction of the mechanical structure, which makes the design more difficult. At the same time, because it is an obliquely incident slit light beam, the light spot focused at the imaging position will have changes in the spot slit width and light intensity in the X-axis direction of the sample plane, resulting in uneven imaging light spot intensity and slit slit width (which is directly proportional to the angle of oblique incidence). For example, the slit light path of the NIDEK NT-530P is incident from the front and focused through the air jet tube to illuminate the human cornea. The slit light cannot penetrate the air jet protection plate and filter, so only the light beam in the air jet tube is emitted. The slit light spot length is 4mm at the working distance of 11mm, so the range of corneal imaging can only be within the 4mm field of view, which limits the analysis area of the cornea and sclera in biomechanics.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a slit optical path generation system based on an air-blowing non-contact tonometer is provided.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A slit optical path generation system based on an air-blowing non-contact tonometer, including a main slit optical path system and a compensating slit optical path system;

[0008] The main slit optical path system includes a slit lamp group 1 and a lens group 1, and the compensating slit optical path system includes a slit lamp group 2 and a lens group 2. The lens group 1 and the lens group 2 are used in conjugate and form a conjugate lens group.

[0009] The conjugate lens group includes a flat beam splitter, a right-angle prism 1, a right-angle prism 2, a sealing mirror, a hollow mirror and a protective sheet;

[0010] The output light of the slit lamp assembly 1 is incident from the front of the first mirror surface of the flat beam splitter, then reflected by the right-angle prism 1 and the right-angle prism 2, passes through the sealing mirror, the hollow mirror and the protective sheet, and the air injection pipe connects the hollow mirror and the protective sheet, thereby obtaining the main slit light path and forming a slit light spot with a field of view of 20 mm;

[0011] The output light of the slit lamp group 2 is incident from the front of the second mirror surface of the flat beam splitter, then reflected by the right-angle prism 1 and the right-angle prism 2, passes through the sealing mirror, the hollow mirror and the protective sheet, and the air jet pipe connects the hollow mirror and the protective sheet, thereby obtaining a slit light path to compensate for the slit and forming a slit light spot with a field of view of 7mm.

[0012] The following is a technical solution further limited by the present invention, wherein the sealing mirror, the hollow mirror and the protective sheet are all coated with an anti-reflection film for the slit light band.

[0013] The following is a technical solution further limited by the present invention, wherein the overall length of the main slit optical path system does not exceed 110 mm.

[0014] The following is a technical solution further limited by the present invention, wherein the overall length of the crack-compensating optical path system does not exceed 144 mm.

[0015] The following is a technical solution further limited by the present invention, wherein the numerical apertures of the slit imaging light spots of the main slit optical path system and the compensating slit optical path system are the same.

[0016] The following is a technical solution further limited by the present invention, wherein the distance between the flat beam splitter and the first right-angle prism is greater than 25 mm.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] The present invention designs a main slit optical path system and a compensating slit optical path system. Through a flat-plate beam splitter, the main slit optical path and the compensating slit optical path are combined into a conjugate optical path. By incident on the frontal slit optical path, light intensity uniformity in the length direction of the slit light spot is achieved. This not only solves the problems of difficult design and structure of the oblique double-slit optical path and uneven imaging light spot intensity and slit width, but also, based on frontal incidence imaging, a field of view of 18 mm can be achieved, which is beneficial to imaging of the entire corneal sclera area and further biomechanical analysis.

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the main view of the position distribution of the main slit optical path system modules in the present invention;

[0022] Figure 2 Schematic top view of the position distribution of the main slit optical path system modules in the present invention;

[0023] Figure 3 Schematic diagram of the imaging spot of the main slit optical path system in the present invention;

[0024] Figure 4 This is the intensity distribution diagram of the imaging light spot of the main slit optical path system in the present invention;

[0025] Figure 5 This is a schematic diagram of the main view of the position distribution of the modules of the optical path system for compensating for the cracks in the present invention;

[0026] Figure 6 Schematic top view of the position distribution of the modules of the optical path system for filling the gap in the present invention;

[0027] Figure 7 This is a schematic diagram of the imaging spot of the optical path system for compensating for the cracks in the present invention;

[0028] Figure 8 This is a light intensity distribution diagram of the imaging light spot of the optical path system that compensates for the cracks in the present invention;

[0029] Figure 9 This is a schematic diagram of the main view of the module position distribution of the conjugate optical path system synthesized by the main slit optical path system and the compensating slit optical path system in the present invention;

[0030] Figure 10 This is a schematic diagram of the imaging spot of the conjugate optical path system synthesized by the main slit optical path system and the compensating slit optical path system in the present invention;

[0031] Figure 11 It is a light intensity distribution diagram of the imaging light spot of the conjugate optical path system synthesized by the main slit optical path system and the compensating slit optical path system in the present invention. DETAILED DESCRIPTION

[0032] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] This embodiment provides a slit optical path generation system based on an air-puff non-contact tonometer, which is composed of a main slit optical path system, a supplementary slit optical path system, and an intraocular pressure measurement module. The intraocular pressure measurement module includes an air-puff air tube.

[0034] like Figure 1 and 2 As shown, the main slit light path system includes a slit lamp group 1 and a lens group 1. The purpose of this system is to form a slit light spot with a field of view of 20mm, and the numerical aperture of the slit imaging light spot is set to 0.091. The slit lamp group 1 includes LED lamp beads, a light homogenizer and a slit lens arranged in sequence (lenses are set in front and behind the slit lens according to actual needs). The lens group 1 includes a flat beam splitter, a right-angle prism 1, a right-angle prism 2, a sealing mirror, a hollow mirror and a protective sheet. The output light of the slit lamp group 1 (i.e., the slit beam 1) is incident from the front of the first mirror surface of the flat beam splitter, and then reflected by the right-angle prism 1 and the right-angle prism 2, passing through a 1mm sealing mirror, a 5mm hollow mirror and a protective sheet inclined at 30°, and the air jet pipe connects the hollow mirror and the protective sheet (including a filter), thereby obtaining the main slit light path and forming a slit light spot with a field of view of 20mm, as shown in FIG. Figure 3 and 4 As shown, the air duct blocks some light, weakening the intensity of a central portion of the slit beam. The duct wall blocks the beam, resulting in black areas at both ends of the central portion of the spot image. To ensure that as much of the entire slit beam as possible reaches the human eye, the sealing mirror, hollow mirror, and protective film are all coated with an anti-reflection coating specific to the slit light wavelength band.

[0035] Due to the overall space limitations of the system, the overall length of the main slit optical path system does not exceed 110mm. The distance between the lens group one and the lens closest to the slit lens is set to be no less than 5mm in order to prevent the structural installation space of the lens and the slit lens from being too small. The tolerance range of the front and rear movable of the slit lens is set to ±1.5mm. The main slit optical path system has an object field of view of ±10mm. To ensure that the light source can accommodate three LED lamp beads with a side length of 2mm, the image field of view needs to be no less than ±3.5mm, so the magnification of the system is set to less than -0.35. Taking into account the spatial arrangement of the slit optical path system, the position of the flat beam splitter needs to be greater than 25mm away from the right-angle prism one.

[0036] like Figure 5 and6 As shown, the slit light path compensation system includes slit lamp assembly 2 and lens assembly 2. The purpose of this system is to compensate for the weaker light intensity in the middle part. The field of view is within the 7mm range, and the numerical aperture of the slit imaging spot also needs to match 0.091 of the slit beam of the main slit light path system. Therefore, the slit beam is designed to enter the human eye through the air duct, forming a slit light spot with a field of view of 7mm. Slit lamp assembly 2 includes LED beads, a light homogenizer, and a slit lens arranged in sequence (lenses are placed before and after the slit lens according to actual needs). Lens assembly 2 includes a flat beam splitter, right-angle prism 1, right-angle prism 2, a sealing mirror, a hollow mirror, and a protective sheet. The output light of the slit lamp group 2 (i.e., slit beam 2) is incident from the front of the second mirror surface of the flat beam splitter, and then reflected by the right-angle prism 1 and the right-angle prism 2, passing through the 1mm sealing mirror inclined at 30°, the 5mm hollow mirror and the protective sheet, and the air jet pipe connecting the hollow mirror and the protective sheet (including the filter), thereby obtaining a slit light path. The field of view of the light spot of the slit beam 2 incident from the inside of the air jet pipe is not less than 7mm. Figure 7 and 8 As shown, it just fills the middle part of the incident spot of the split beam.

[0037] Due to the overall space limitations of the system, the overall length of the slit optical path system does not exceed 144mm. The distance between the lens group 2 and the closest lens to the slit lens is set to no less than 5mm to prevent the structural installation space between the lens and the slit lens from being too small. The tolerance range of the slit lens's front and rear movement is set to ±1.5mm. The slit optical path system has an object-side field of view of ±3.5mm. Because it is an intermediate compensation beam, in order to prevent overexposure when superimposed on the original light intensity, the light source intensity of the slit optical path system can be smaller. Therefore, it is ensured that the light source can accommodate a 2mm side LED lamp bead. The image-side field of view needs to be no less than ±1mm, so the system's magnification is set to less than -0.28. The position of the flat beam splitter needs to be at least 25mm away from the right-angle prism.

[0038] like Figure 9As shown, the lens group 1 of the main slit optical path system and the lens group 2 of the complementary slit optical path system are used in conjugate and form a conjugate lens group. The conjugate lens group includes a flat beam splitter, a right angle prism 1, a right angle prism 2, a sealing mirror, a hollow mirror and a protective sheet. The output light of slit lamp group 1 (i.e. slit beam 1) is incident from the front of the first mirror surface of the flat beam splitter, and then reflected by right-angle prism 1 and right-angle prism 2, passes through a 1mm sealed mirror tilted at 30°, a 5mm hollow mirror and a protective sheet, and the air jet pipe connects the hollow mirror and the protective sheet, thereby obtaining a main slit light path, forming a slit light spot with a field of view of 20mm. At this time, the light intensity of the middle part of slit beam 1 is weakened; the output light of slit lamp group 2 (i.e. slit beam 2) is incident from the front of the second mirror surface of the flat beam splitter, and then reflected by right-angle prism 1 and right-angle prism 2, passes through a 1mm sealed mirror tilted at 30°, a 5mm hollow mirror and a protective sheet, and the air jet pipe connects the hollow mirror and the protective sheet, thereby obtaining a compensating slit light path. The field of view of the light spot of slit beam 2 incident from the inside of the air jet pipe is not less than 7mm, which just compensates for the middle part of the light spot of slit beam 1. Figure 10 and 11 shown.

[0039] When the cornea has uneven light intensity in the slit spot, the corneal tomogram will also have uneven imaging light intensity. Therefore, the brightness information of the corneal tomogram is finally homogenized through the subsequent image algorithm to make the imaging effect of the light intensity uniform.

[0040] In summary, the present invention uses the frontal slit light path as the incident light, passes through the air jet pipe, and focuses on the imaging point, wherein the paint protection sheet and the filter do not block the slit light, so the slit light spot at the imaging point at this time is a slit light spot with a field of view greater than 18 mm. Due to the obstruction of the air jet pipe in the middle, the light intensity of the middle section of the slit light spot (the light beam passing through the air jet pipe) is weakened, and there will be a small section on both sides of the middle section with a light intensity of almost 0 (obstruction of the tracheal wall, thickness of 0.5 mm). The protective sheet makes the light intensity on both sides stronger; since there is a part of the light intensity in the middle of the slit light spot that is weak, it affects the imaging effect. Therefore, on the basis of the main slit light path, a compensating slit light path is added (a conjugate light path is synthesized with the main slit light path through a flat-plate beam splitter), which also uses the frontal incidence method. The function of the compensating slit light path is to compensate for the weaker part of the light intensity in the middle of the slit light spot imaged by the main slit light path, thereby achieving light intensity uniformity in the length direction of the slit light spot. It not only solves the problems of difficult design and structure of oblique double-slit optical path and uneven imaging light intensity and slit width, but also, based on frontal incidence imaging, it can achieve a field of view of 18mm, and the corneal and scleral areas can be imaged, which is conducive to biomechanical analysis.

[0041] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any person skilled in the art can utilize the methods and technical contents disclosed above to make many possible variations and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments with equivalent variations. Therefore, any equivalent variations made in accordance with the shape, structure, and principles of the present invention without departing from the content of the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A slit optical path generation system based on an air-blowing non-contact tonometer, characterized in that: It includes a main slit optical path system and a compensating slit optical path system; The main slit optical path system includes a slit lamp group 1 and a lens group 1, and the compensating slit optical path system includes a slit lamp group 2 and a lens group 2. The lens group 1 and the lens group 2 are used in conjugate and form a conjugate lens group. The conjugate lens group includes a flat beam splitter, a right-angle prism 1, a right-angle prism 2, a sealing mirror, a hollow mirror and a protective sheet; The output light of the slit lamp assembly 1 is incident from the front of the first mirror surface of the flat beam splitter, then reflected by the right-angle prism 1 and the right-angle prism 2, passes through the sealing mirror, the hollow mirror and the protective sheet, and the air injection pipe connects the hollow mirror and the protective sheet, thereby obtaining the main slit light path; The output light of the second slit lamp group is incident from the front of the second mirror surface of the flat beam splitter, then reflected by the right-angle prism 1 and the right-angle prism 2, passes through the sealing mirror, the hollow mirror and the protective sheet, and the air jet pipe connects the hollow mirror and the protective sheet, thereby obtaining a slit light path.

2. The slit light path generation system according to claim 1, wherein: The sealing mirror, the hollow mirror and the protective sheet are all coated with an anti-reflection film for the slit light band.

3. The slit light path generation system according to claim 1, wherein: The overall length of the main slit optical path system does not exceed 110 mm.

4. The slit light path generation system according to claim 1, wherein: The overall length of the crack-compensating optical path system does not exceed 144 mm.

5. The slit light path generation system according to claim 1, wherein: The numerical apertures of the slit imaging light spots of the main slit optical path system and the compensating slit optical path system are the same.

6. The slit light path generation system according to claim 1, wherein: The distance between the flat beam splitter and the first right-angle prism is greater than 25 mm.

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