CN113854959A - Non-contact intraocular pressure measuring method and device based on linear array camera - Google Patents
Non-contact intraocular pressure measuring method and device based on linear array camera Download PDFInfo
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Abstract
The invention relates to the technical field of medical detection, in particular to a non-contact intraocular pressure measuring method and a non-contact intraocular pressure measuring device based on a linear array camera, which comprise a structured light projector, a linear array image sensor and a linear array image sensor, wherein the structured light projector is used for projecting a linear array image on an eyeball to be detected, and light is reflected by the eyeball after being projected to the eyeball; the working lens group is used for reflecting to obtain left and right parallax images of the eyeballs to be detected, focusing the left and right parallax images to form images and transmitting the images to the image sensor; the non-contact pneumatic device is used for generating air flow to enable the cornea to be displaced inwards to form a flat state, and when the air flow is closed and stopped, the cornea is enabled to rebound to the original position and is in the flat state again; and the image sensor is used for receiving the left and right disparity maps focused and imaged by the working lens group, converting the left and right disparity maps into digital images, and calculating the intraocular pressure value of the eyeball to be detected according to the applanation state of the cornea by the calculating module. The intraocular pressure value is obtained through calculation, the risk of infection is avoided, and meanwhile, the intraocular pressure measuring method has higher measuring precision and very strong market application prospect.
Description
Technical Field
The invention relates to the technical field of medical detection, in particular to a non-contact intraocular pressure measuring method and device based on a linear array camera.
Background
With the continuous development of science and technology, digital equipment with a display screen, such as mobile phones, computers, tablets, XR near-eye display glasses and the like, is more and more popular, the time for people to use the digital products is continuously increased, the eyes of people are in extremely frequent contact with the display screen, even excessive situations occur, and the probability of eye lesion is increased. The improper posture and excessive use of the eyes lead to an increasing number of patients with ophthalmic diseases such as myopia, glaucoma, etc.
Intraocular pressure has long been an important diagnostic indicator in ophthalmology, and glaucoma, the most common eye disease in humans with blindness, is caused by ocular hypertension. The change of the intraocular pressure has certain influence on the shape of the eyeball, so that the medical data which is critical to the human eye can be directly or indirectly acquired through the detection of the shape of the human eye, and the medical data can be used for preventing, diagnosing or treating the ophthalmic diseases. While the most common applanation tonometers require contact with the cornea of the subject, there are eye hygiene issues if sterilization is not attended to, and therefore non-contact tonometers are increasingly in demand.
Applanation tonometry is currently one of the most common tonometry methods internationally and has long been recognized as a standard specification for tonometry. The Imber-Fick law states that the internal pressure of a liquid filled sphere can be determined by measuring the force required to flatten the surface of the sphere. The conventional applanation tonometer is designed according to the law, and in the measurement process of the applanation tonometer, a small flat pressure probe is used for pressurizing the cornea, and the contact area between the required pressurized pressure and the cornea is used for estimating the intraocular pressure. Instead, the non-contact tonometer applanates a constant area (3.06 mm diameter) of the corneal apex with an air pulse force, and the time required for the applanation area is measured and converted to intraocular pressure.
Based on the method, the invention provides a non-contact intraocular pressure measuring method and a non-contact intraocular pressure measuring device based on a linear array camera, and the intraocular pressure is deduced by applying a machine vision technology to analyze the deformation process of an eyeball in the measuring process.
Disclosure of Invention
Aiming at the defects of the prior art, the invention discloses a non-contact intraocular pressure measuring method and a non-contact intraocular pressure measuring device based on a linear array camera, which are used for analyzing the process of eyeball deformation by applying a machine vision technology in the measuring process so as to conjecture intraocular pressure.
The invention is realized by the following technical scheme:
in a first aspect, the invention provides a non-contact intraocular pressure measuring device based on a line camera, comprising
The structured light projector is used for projecting a linear array pattern on an eyeball to be detected, and light is reflected by the eyeball after being projected to the eyeball;
the working lens group is used for reflecting to obtain left and right parallax images of the eyeballs to be detected, focusing the left and right parallax images to form images and transmitting the images to the image sensor;
the non-contact pneumatic device is used for generating air flow to enable the cornea to be displaced inwards to form a flat state, and when the air flow is closed and stopped, the cornea is enabled to rebound to the original position and is in the flat state again;
and the image sensor is used for receiving the left and right disparity maps focused and imaged by the working lens group, converting the left and right disparity maps into digital images, and calculating the intraocular pressure value of the eyeball to be detected according to the applanation state of the cornea by the calculating module.
Furthermore, the working lens group comprises a reflector group and an imaging lens group.
Further, the mirror group is composed of mirrors M1, M2, M3 and M4, wherein the M1 and M2 are used for transmitting the left parallax image of the eyeball, and the M3 and M4 are used for transmitting the right parallax image of the eyeball.
Furthermore, the reflector group is used for transmitting left and right parallax images of human eyeballs to the imaging lens group.
Furthermore, the imaging lens group consists of a plurality of groups of lenses and is used for focusing and imaging left and right parallax images of human eyeballs input by the reflector group to the image sensor.
Furthermore, when the structured light projector works, the linear array pattern with the set angle range is projected to the eyeball, the range covers the whole eyeball, namely the whole eyeball has the linear array pattern, when the light of the structured light projector is projected to the eyeball of the person, the light is reflected by the eyeball, wherein in the reflected light, part of the light enters the reflecting lens group and then passes through the imaging lens group to be imaged on the image sensor.
Furthermore, let the most peripheral light rays of all light rays participating in imaging be R10, R20, R30 and R40, and using the central axis of eyeball as boundary, then R10 and R20 are located on the same side, and R30 and R40 are located on the other side, then in the working lens group,
after the R10 and R20 and all the rays in between enter the mirror M1, they are reflected as the rays R11 and R21 and all the rays in between;
the rays R11 and R21 and all rays in between are incident on the mirror M2 and are reflected as rays R12 and R22 and all rays in between;
the R12 and R22 and all light rays in between are converted into light rays R13 and R23 by the imaging lens group and imaged on the image sensor, forming a left parallax image of the eyeball.
After the R30 and R40 and all the rays in between enter the mirror M4, they are reflected as the rays R31 and R41 and all the rays in between;
the rays R31 and R41 and all rays in between are incident on the mirror M3 and are reflected as rays R32 and R42 and all rays in between;
the R32 and R42 and all light rays in between are converted into light rays R33 and R43 by the optical lens group and imaged on the image sensor, forming a right parallax image of the eyeball.
Furthermore, the structured light generator forms an included angle b with the middle axis, the camera forms an included angle a with the middle axis, the distance d is obtained according to a triangulation method, if the linear array camera is an equivalent binocular camera comprising a left half and a right half with parallax, the depth distance d is calculated through binocular vision, and the formula is as follows:
further, the measuring device software portion includes:
the linear array camera control module is used for controlling the linear array camera and image data acquisition and providing data to the calculation module so as to calculate the internal and external leveling points and intraocular pressure;
the structured light projection control module is used for controlling the intensity and the switch of the structured light;
the blowing equipment control module is used for accurately controlling blowing strength and switching;
the RGB camera control module is used for controlling the RGB camera, acquiring data and providing the data to the computing module to perform eyeball tracking and combiner alignment;
the combiner angle control module is used for controlling the angle of the combiner and adjusting the real-time alignment of the combiner and the eyeball according to the eyeball pose calculated by the calculation module and the calculation result of the combiner posture;
the display module is used for displaying the intraocular pressure value obtained through calculation;
and the calculation module is mainly used for eyeball pose tracking, RGB image processing, linear array image processing, internal and external flattening point matching calculation and intraocular pressure calculation.
In a second aspect, the invention provides a non-contact intraocular pressure measuring method based on a line camera, which comprises the following steps:
s1 initializing and starting the system, starting the RGB camera to identify the cornea position of the eye in the region to be detected, and judging whether the combiner is aligned with the cornea center according to calculation;
s2 if not, the combiner angle adjusting control module adjusts the combiner angle to align it with the cornea center of the tested person, if so, the measurement is started;
s3, starting linear array pattern structured light, and simultaneously, starting to record shape change data of an Nms cornea before air blowing by a linear array camera as datum data, wherein N is a positive integer;
s4, blowing is started, the linear array camera continues to record the corneal deformation data, and after the data recording is finished, blowing is stopped, and the data recording is finished;
s5, synthesizing the recorded data into a sample picture, calculating depth data according to each pixel point in the picture, obtaining inner and outer flat pressure points according to the depth data, and finally obtaining an intraocular pressure value of the detected eye.
The invention has the beneficial effects that:
the invention is based on the Imber-Fick law, uses a non-contact pneumatic device to generate a rapid airflow to generate pressure on the cornea, and uses a high-precision linear array camera to monitor the change of the cornea, thereby inferring the intraocular pressure, avoiding the risk of infection, having higher measuring precision and having strong market application prospect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a software control block diagram of a non-contact tonometer based on a line camera;
FIG. 2 is a schematic diagram of intraocular pressure calculation of a non-contact intraocular pressure measuring device based on a line camera;
FIG. 3 is a diagram of the structure of an optical system according to an embodiment of the present invention;
FIG. 4 is a schematic view of a linear array pattern projected by a structured light projector to cover the entire eyeball according to an embodiment of the present invention;
FIG. 5 is a schematic diagram illustrating an angle between a light generator and a central axis according to an embodiment of the present invention;
FIG. 6 is a schematic view of the depth distance calculated by the embodiment of the present invention;
FIG. 7 is a data diagram of a single sampling of a line camera at a certain time point according to an embodiment of the present invention;
FIG. 8 is a diagram of 1000 frames acquired according to an embodiment of the present invention, stitched into 6000x1000 pixels as a function of time;
FIG. 9 is a schematic view of an exemplary embodiment of an insufflation generator positioned directly opposite the direction of eye gaze, i.e., normal to the tangent plane of the eye;
FIG. 10 is a flow chart illustrating an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The embodiment provides a non-contact intraocular pressure measuring device based on a line camera, which is shown in figure 1 and comprises
The structured light projector is used for projecting a linear array pattern on an eyeball to be detected, and light is reflected by the eyeball after being projected to the eyeball;
the working lens group is used for reflecting to obtain left and right parallax images of the eyeballs to be detected, focusing the left and right parallax images to form images and transmitting the images to the image sensor;
the non-contact pneumatic device is used for generating air flow to enable the cornea to be displaced inwards to form a flat state, and when the air flow is closed and stopped, the cornea is enabled to rebound to the original position and is in the flat state again;
and the image sensor is used for receiving the left and right disparity maps focused and imaged by the working lens group, converting the left and right disparity maps into digital images, and calculating the intraocular pressure value of the eyeball to be detected according to the applanation state of the cornea by the calculating module.
The software part comprises:
the linear array camera control module is used for controlling the linear array camera and image data acquisition and providing data to the calculation module so as to calculate the internal and external leveling points and intraocular pressure;
the structured light projection control module is used for controlling the intensity and the switch of the structured light;
the blowing equipment control module is used for accurately controlling blowing strength and switching;
the RGB camera control module is used for controlling the RGB camera, acquiring data and providing the data to the computing module to perform eyeball tracking and combiner alignment;
the combiner angle control module is used for controlling the angle of the combiner and adjusting the real-time alignment of the combiner and the eyeball according to the eyeball pose calculated by the calculation module and the calculation result of the combiner posture;
the display module is used for displaying the intraocular pressure value obtained through calculation;
and the calculation module is mainly used for eyeball pose tracking, RGB image processing, linear array image processing, internal and external flattening point matching calculation and intraocular pressure calculation.
The embodiment shown in fig. 2 is based on the Imber-Fick law, a non-contact pneumatic device is used for generating a rapid airflow to generate pressure on the cornea, and a high-precision linear array camera is used for monitoring the change of the cornea.
The air flow of this embodiment displaces the cornea inwardly and flattens in the process, undergoing a first applanation. The airflow then closes and the pressure on the eyeball drops and the cornea springs back to its original position. During rebound, the cornea is again in a flattened state, which is a second applanation. Two independent intraocular pressure values Pa and Pb are generated in the internal and external flattening processes. The key technical point for estimating the two intraocular pressure values is to calculate two flattening points P2 and P4.
Example 2
In a specific implementation aspect, this embodiment provides an optical portion of a non-contact tonometer based on a line camera, as shown in fig. 3 below, the whole optical system is composed of four portions: structured light projector, reflector group, imaging lens group, image sensor.
The structured light projector of the embodiment mainly plays a role in projecting linear array patterns on human eyeball.
The reflector group of the embodiment is composed of four reflectors M1-M4, and is used for transmitting left and right parallax images of human eyes to the imaging lens group, wherein M1 and M2 are used for transmitting left parallax images of eyes, and M3 and M4 are used for transmitting right parallax images of eyes.
The imaging lens group of the present embodiment is composed of 2 lenses, and is used for focusing and imaging left and right parallax images of human eyes input by the reflector group to the image sensor.
The image sensor of the present embodiment is used for converting left and right parallax images of an eyeball into digital images.
The structured light projector of the present embodiment works to project a linear array pattern with a certain angle range onto the eyeball, the range covers the whole eyeball, namely the whole eyeball has the linear array pattern, when the light of the structured light projector is projected onto the eyeball, the light can be reflected by the eyeball, and in the reflected light, part of the light can enter the reflection lens group and further pass through the imaging lens group to be imaged on the image sensor.
The most marginal rays of all the rays participating in imaging in the embodiment are R10, R20, R30 and R40, and are bounded by the central axis of the eyeball, R10 and R20 are located on the same side, and R30 and R40 are located on the other side.
In this embodiment, after the R10 and the R20 and all the light rays in between are incident on the mirror M1, they are reflected as the light rays R11 and R21 and all the light rays in between, next, the light rays R11 and R21 and all the light rays in between are incident on the mirror M2, they are reflected as the light rays R12 and R22 and all the light rays in between, then, the light rays R12 and R22 and all the light rays in between are converted into the light rays R13 and R23 by the imaging lens group and imaged on the image sensor, and a left parallax image of the eyeball is formed.
In this embodiment, after the R30 and the R40 and all the light rays in between are incident on the mirror M4, they are reflected as the light rays R31 and R41 and all the light rays in between, next, the light rays R31 and R41 and all the light rays in between are incident on the mirror M3, they are reflected as the light rays R32 and R42 and all the light rays in between, then, the light rays R33 and R43 are changed into the light rays R32 and R42 by the optical lens group and imaged on the image sensor, and a right parallax image of the eyeball is formed.
Example 3
In a specific implementation level, the present embodiment discusses an experiment of a non-contact tonometry device based on a line camera, as shown in fig. 4, a line pattern projected by a structured light projector covers the whole eyeball, and when the height of the surface of the eyeball changes, the line pattern projected on the surface of the eyeball changes, so that an accurate three-dimensional profile can be calculated.
As shown in FIG. 5, the structured light generator forms an angle b with the central axis, the camera forms an angle a with the central axis, and according to the triangulation method, we can obtain the distance d, and l is the fixed distance between the structured light generator and the camera. In addition, the optical system divides a linear array camera into a left equivalent binocular camera and a right equivalent binocular camera with parallax, and the depth distance d can be calculated through binocular vision.
Is given by the formula
As shown in fig. 6. In order to introduce few variables as possible and simplify the structure of the collector, the transverse center position of the eyeball is fixedly scanned, and a group of complete image data can be collected in the whole blowing period to carry out analysis and calculation.
As shown in fig. 7, data is sampled once for a certain time point of the line camera. In the implementation process, we use a line camera with the resolution of 6000x1 pixels and 20000 frames (20kHz) per second, record the data 20ms before the air blowing, use the data 20ms as the reference of the deformation of the eyeball, then complete the air blowing for 30ms and sample the process. Thus, a total of 1000 frames are acquired and we calculate the inner and outer flattening points (P2 and P4) from the subsequent 600 frames. The 1000 frames collected are spliced into a graph of 6000x1000 pixels as a function of time as shown in fig. 8.
As shown in fig. 9, the blowing generator faces the gaze direction of the eyeball, i.e. the normal position of the tangent plane of the eyeball, the structured light generator forms an included angle b with the blowing generator, the line array camera forms an included angle a with the left and right light splitting systems and the blowing generator, the three parts are all fixed in a whole body (the blowing and line array structure generating acquisition combiner), and during alignment, the angle of the combiner is only required to be adjusted, and the three parts are kept unchanged, so that the complexity in algorithm design is reduced. An additional RGB camera is separately mounted below the combiner to track the eye position and ensure that the combiner is aligned with the cornea center.
Example 4
In a specific implementation aspect, this embodiment provides a non-contact tonometry method based on a line camera, including the following steps:
s1 initializing and starting the system, starting the RGB camera to identify the cornea position of the eye in the region to be detected, and judging whether the combiner is aligned with the cornea center according to calculation;
s2 if not, the combiner angle adjusting control module adjusts the combiner angle to align it with the cornea center of the tested person, if so, the measurement is started;
s3, starting linear array pattern structured light, and simultaneously, starting to record shape change data of an Nms cornea before air blowing by a linear array camera as datum data, wherein N is a positive integer;
s4, blowing is started, the linear array camera continues to record the corneal deformation data, and after the data recording is finished, blowing is stopped, and the data recording is finished;
s5, synthesizing the recorded data into a sample picture, calculating depth data according to each pixel point in the picture, obtaining inner and outer flat pressure points according to the depth data, and finally obtaining an intraocular pressure value of the detected eye.
Referring to fig. 10, the user starts the tonometer to approach the front of the eye to be measured initially, at this time, the equipment system finishes starting, starts the RGB camera to recognize the cornea position, and obtains the cornea position through calculation by the calculation module, and if the combiner is not aligned with the cornea center, the combiner angle adjustment control module adjusts the combiner angle to align the combiner with the cornea center of the subject.
In the embodiment, after the combiner is detected to be aligned with the cornea of the testee, the measurement is started, the structured light projection control module starts the linear array pattern structured light, the linear array camera starts to record the shape change data of the cornea for 20ms before as a reference, and after 20ms, the air blowing equipment control module controls the air blowing equipment to rapidly generate air flow, meanwhile, the linear array camera continues to record the deformation data of the cornea, and after the data recording is finished, the air blowing device is completely closed.
Then, the calculation module synthesizes the recorded 1000 frame data into a 6000x1000 picture, calculates the depth data of each pixel point in the picture, calculates the inner and outer pressure points P2 and P4 from the depth data, further obtains the intraocular pressure value, and finally displays the intraocular pressure value on the display module.
In conclusion, the invention is based on the Imber-Fick law, a non-contact pneumatic device is used for generating a rapid airflow to generate pressure on the cornea, and a high-precision linear array camera is used for monitoring the change of the cornea, so that the intraocular pressure is presumed, the risk of infection is avoided, and meanwhile, the invention has higher measurement precision and very strong market application prospect.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A non-contact intraocular pressure measuring device based on a linear array camera is characterized by comprising
The structured light projector is used for projecting a linear array pattern on an eyeball to be detected, and light is reflected by the eyeball after being projected to the eyeball;
the working lens group is used for reflecting to obtain left and right parallax images of the eyeballs to be detected, focusing the left and right parallax images to form images and transmitting the images to the image sensor;
the non-contact pneumatic device is used for generating air flow to enable the cornea to be displaced inwards to form a flat state, and when the air flow is closed and stopped, the cornea is enabled to rebound to the original position and is in the flat state again;
and the image sensor is used for receiving the left and right disparity maps focused and imaged by the working lens group, converting the left and right disparity maps into digital images, and calculating the intraocular pressure value of the eyeball to be detected according to the applanation state of the cornea by the calculating module.
2. The linear array camera-based non-contact tonometry device according to claim 1, wherein said working lens group comprises a mirror group and an imaging lens group.
3. The linear array camera-based non-contact tonometry device according to claim 2, wherein the mirror group is composed of mirrors M1, M2, M3 and M4, wherein the mirrors M1 and M2 are used for transmitting left parallax images of eyes, and the mirrors M3 and M4 are used for transmitting right parallax images of eyes.
4. The linear array camera-based non-contact tonometry device according to claim 2, wherein said mirror group is used for transmitting left and right parallax images of human eyes to said imaging lens group.
5. The linear array camera-based non-contact tonometry device according to claim 2, wherein the imaging lens group is composed of a plurality of groups of lenses for focusing and imaging the left and right parallax images of the human eyeball inputted by the reflector group to the image sensor.
6. The linear array camera-based non-contact intraocular pressure measuring device according to claim 1, wherein the structured light projector is operative to project a linear array pattern with a predetermined angular range onto the eyeball, the range covering the entire eyeball, i.e. the entire eyeball having the linear array pattern, and when the structured light projector projects the light onto the eyeball, the light is reflected by the eyeball, wherein, of the reflected light, a portion of the reflected light enters the reflection lens group and passes through the imaging lens group to be imaged on the image sensor.
7. The linear array camera-based non-contact tonometry device according to claim 6, wherein let the most peripheral light rays of all light rays participating in imaging be R10, R20, R30, R40, and bound by the central axis of eyeball, then R10 and R20 are located on the same side, and R30 and R40 are located on the other side, then in the working lens group,
after the R10 and R20 and all the rays in between enter the mirror M1, they are reflected as the rays R11 and R21 and all the rays in between;
the rays R11 and R21 and all rays in between are incident on the mirror M2 and are reflected as rays R12 and R22 and all rays in between;
the R12 and R22 and all light rays in between are converted into light rays R13 and R23 by the imaging lens group and imaged on the image sensor, forming a left parallax image of the eyeball.
After the R30 and R40 and all the rays in between enter the mirror M4, they are reflected as the rays R31 and R41 and all the rays in between;
the rays R31 and R41 and all rays in between are incident on the mirror M3 and are reflected as rays R32 and R42 and all rays in between;
the R32 and R42 and all light rays in between are converted into light rays R33 and R43 by the optical lens group and imaged on the image sensor, forming a right parallax image of the eyeball.
8. The non-contact tonometry device based on a line camera as claimed in claim 1, wherein the structured light generator forms an angle b with the central axis, the camera forms an angle a with the central axis, the distance d is obtained by triangulation, if the line camera is an equivalent binocular camera comprising left and right halves with parallax, the depth distance d is calculated by binocular vision, the formula is as follows:
wherein l is the fixed distance between the structured light generator and the camera.
9. The linear array camera-based non-contact tonometer according to claim 1, wherein said measuring device software portion comprises:
the linear array camera control module is used for controlling the linear array camera and image data acquisition and providing data to the calculation module so as to calculate the internal and external leveling points and intraocular pressure;
the structured light projection control module is used for controlling the intensity and the switch of the structured light;
the blowing equipment control module is used for accurately controlling blowing strength and switching;
the RGB camera control module is used for controlling the RGB camera, acquiring data and providing the data to the computing module to perform eyeball tracking and combiner alignment;
the combiner angle control module is used for controlling the angle of the combiner and adjusting the real-time alignment of the combiner and the eyeball according to the eyeball pose calculated by the calculation module and the calculation result of the combiner posture;
the display module is used for displaying the intraocular pressure value obtained through calculation;
and the calculation module is mainly used for eyeball pose tracking, RGB image processing, linear array image processing, internal and external flattening point matching calculation and intraocular pressure calculation.
10. A non-contact intraocular pressure measuring method based on a linear array camera is characterized by comprising the following steps:
s1 initializing and starting the system, starting the RGB camera to identify the cornea position of the eye in the region to be detected, and judging whether the combiner is aligned with the cornea center according to calculation;
s2 if not, the combiner angle adjusting control module adjusts the combiner angle to align it with the cornea center of the tested person, if so, the measurement is started;
s3, starting linear array pattern structured light, and simultaneously, starting to record shape change data of an Nms cornea before air blowing by a linear array camera as datum data, wherein N is a positive integer;
s4, blowing is started, the linear array camera continues to record the corneal deformation data, and after the data recording is finished, blowing is stopped, and the data recording is finished;
s5, synthesizing the recorded data into a sample picture, calculating depth data according to each pixel point in the picture, obtaining inner and outer flat pressure points according to the depth data, and finally obtaining an intraocular pressure value of the detected eye.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115381393A (en) * | 2022-09-01 | 2022-11-25 | 北京航空航天大学 | Intraocular pressure measuring method and device based on equal thickness interference |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5131739A (en) * | 1988-02-01 | 1992-07-21 | Kabushiki Kaisha Topcon | Ophthalmological instrument for cornea curvature and pressure measurement |
| JPH067304A (en) * | 1993-04-02 | 1994-01-18 | Topcon Corp | Contactless type ophthalmotonometer |
| JPH067306A (en) * | 1993-04-02 | 1994-01-18 | Topcon Corp | Contactless type ophthalmotonometer |
| CN102813501A (en) * | 2012-08-06 | 2012-12-12 | 淮南师范学院 | Dynamic intraocular pressure measuring device and method for controlling probe to be coaxial with eyeball |
| CN102813502A (en) * | 2012-08-06 | 2012-12-12 | 淮南师范学院 | Contact tonometer |
| CN204654882U (en) * | 2015-05-25 | 2015-09-23 | 成都格莱飞科技股份有限公司 | The contactless corneal tonometer of novel low-cost |
| CN206867213U (en) * | 2017-01-10 | 2018-01-12 | 齐齐哈尔医学院附属第三医院(齐齐哈尔医学院附属肿瘤医院) | A kind of non-contact intraocular tension measuring device |
| JP2018047036A (en) * | 2016-09-21 | 2018-03-29 | 株式会社トプコン | Non-contact type tonometer |
| CN108514403A (en) * | 2018-05-10 | 2018-09-11 | 爱纳医疗科技股份有限公司 | A kind of intraocular pressure detection device and method based on laser specklegram principle |
| US20210022608A1 (en) * | 2018-03-12 | 2021-01-28 | Ioppreceyese Ltd. | Non-Contact Home-Tonometry System for Measuring Intraocular Pressure |
-
2021
- 2021-09-26 CN CN202111139392.6A patent/CN113854959A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5131739A (en) * | 1988-02-01 | 1992-07-21 | Kabushiki Kaisha Topcon | Ophthalmological instrument for cornea curvature and pressure measurement |
| JPH067304A (en) * | 1993-04-02 | 1994-01-18 | Topcon Corp | Contactless type ophthalmotonometer |
| JPH067306A (en) * | 1993-04-02 | 1994-01-18 | Topcon Corp | Contactless type ophthalmotonometer |
| CN102813501A (en) * | 2012-08-06 | 2012-12-12 | 淮南师范学院 | Dynamic intraocular pressure measuring device and method for controlling probe to be coaxial with eyeball |
| CN102813502A (en) * | 2012-08-06 | 2012-12-12 | 淮南师范学院 | Contact tonometer |
| CN204654882U (en) * | 2015-05-25 | 2015-09-23 | 成都格莱飞科技股份有限公司 | The contactless corneal tonometer of novel low-cost |
| JP2018047036A (en) * | 2016-09-21 | 2018-03-29 | 株式会社トプコン | Non-contact type tonometer |
| CN206867213U (en) * | 2017-01-10 | 2018-01-12 | 齐齐哈尔医学院附属第三医院(齐齐哈尔医学院附属肿瘤医院) | A kind of non-contact intraocular tension measuring device |
| US20210022608A1 (en) * | 2018-03-12 | 2021-01-28 | Ioppreceyese Ltd. | Non-Contact Home-Tonometry System for Measuring Intraocular Pressure |
| CN108514403A (en) * | 2018-05-10 | 2018-09-11 | 爱纳医疗科技股份有限公司 | A kind of intraocular pressure detection device and method based on laser specklegram principle |
Non-Patent Citations (2)
| Title |
|---|
| 张立国: "爬壁机器人结构光视觉跟踪", 31 March 2021, pages: 16 - 18 * |
| 梁晋: "3D反求技术", 31 January 2019, pages: 158 - 160 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115381393A (en) * | 2022-09-01 | 2022-11-25 | 北京航空航天大学 | Intraocular pressure measuring method and device based on equal thickness interference |
| CN115381393B (en) * | 2022-09-01 | 2024-06-07 | 北京航空航天大学 | Intraocular pressure measurement method and device based on equal-thickness interference |
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