An eyepiece type automatic pupil light reflex detection device

Abstract

The present invention relates to an eyepiece type automatic pupillary light reflex detection device, comprising a camera for acquiring human eye images; a light stimulation source for providing at least one stimulation light source to the user; a distance measurement sensor for measuring the distance from the camera to the human eye; an image analysis module for complementing the pupil; and a data analysis module for obtaining pupil data based on the value of the data measurement sensor and the complemented pupil image. The advantages of the present invention are as follows: it is convenient to carry and has good compatibility; it provides a variety of light sources and sound sources, facilitating the selection of stimulation types, meets the requirements of a dark room through a semi-reflective mirror, and fills the pupil with light through an infrared fill light, facilitating the acquisition of clear images; through the distance measurement sensor, the distance between the pupil and the detection device can be accurately obtained; through the complementing algorithm, various objective parameters of the pupillary light reflex can be accurately extracted, which is very suitable for the clinical and research needs of neurology, ophthalmology, and psychiatry.

Description

Technical Field

[0001] The present invention relates to the technical field of devices for obtaining physiological data of pupils, and particularly to an eyepiece type automatic pupillary light reflex detection device. Background Art

[0002] The pupillary light reflex is a physiological phenomenon, which means that when the pupil is irradiated by visible light, the pupil will constrict, and when the light source is removed, the pupil will quickly return to its original state. Pupil detection usually requires being carried out in a dark room, preferably with a fully enclosed light-shielding environment.

[0003] As a classic simple bedside examination method in neurology, the pupillary light reflex plays an important role in the judgment of nerve injury, disturbance of consciousness, and brain dysfunction. With the development of modern neuroscience, more and more evidence suggests that this examination also has important reference value in aspects such as the assessment of Parkinson's disease, cognitive impairment, and autonomic dysfunction, and is expected to become an electrophysiological biomarker that can objectively reflect disease subtypes. Traditionally, the pupillary light reflex mainly relies on a flashlight, and the examiner completes the assessment through manual examination and naked-eye observation. The results are relatively subjective, unable to be quantitatively analyzed, and not conducive to the homogenization management of multi-center data. Currently, the quantitative pupillary light reflex examination devices on the market mainly come from European and American countries, with high prices, and there is still a lack of instruments with independent intellectual property rights in China.

[0004] Under normal circumstances, the pupils of ordinary people are circular with a diameter of 2 - 6 millimeters, and the sizes of the two pupils are basically the same. When stimulated by light, by analyzing the change process of the pupil diameter and using a certain algorithm, multiple parameters such as latency, stable diameter, minimum diameter, maximum acceleration during pupil constriction, and maximum speed of pupil constriction can be obtained. These data have significant clinical significance.

[0005] Quantitative detection of the pupillary light reflex usually uses a camera to collect the pupil, and through image analysis technology, calculates the pupil diameter D in pixels, and then uses the formula F: the true size of the pupil (M, unit: millimeter) = pupil diameter (D) * the true physical size of each pixel representing the pupil (K, unit: millimeter / pixel, related to the distance from the camera to the pupil) to obtain the physical size of the pupil. When using an electronic method to detect the pupil diameter, it is necessary to obtain the true physical size of the pupil according to the aforementioned formula F. For existing devices, whether it is a fixed detection box or a handheld detector, the distance between the camera and the pupil is not a stable value. Due to various reasons, it is impossible for different subjects to make the distance between the pupil and the camera consistent. Therefore, the problem is that for the pupil diameter detected by existing devices, since K is a fixed value, but due to the aforementioned reasons, K is actually impossible to be a fixed value, resulting in an irreducible error between the true size of the pupil and the measured value.

[0006] In addition, the following problems also exist in the prior art:

[0007] 1. For existing detection devices, when processing the pupil, it is required that the pupil in the collected image is complete in order to effectively calculate the pupil diameter. However, in the actual clinical environment, the subject may not be able to fully expose the pupil during the test, resulting in inaccurate calculation of the pupil diameter.

[0008] 2. The stimulating light source is fixed and single, and cannot achieve switching of multiple color light sources.

[0009] 3. It cannot provide acoustic stimulation.

[0010] 4. The fixed detection box is relatively large in volume, has certain requirements for the inspection site, and is not portable.

[0011] 5. The handheld detector does not have light-shielding property. Summary of the Invention

[0012] In view of the above problems, the present application provides a pupil detection device that can eliminate the influence of distance change on pupil measurement.

[0013] The present application solves the above technical problems through the following technical solutions.

[0014] An eyepiece type automatic pupil light reflex detection device, comprising

[0015] a camera for acquiring an image of the human eye;

[0016] a light stimulation source for providing at least one stimulation light source to the user;

[0017] a distance measurement sensor for measuring the distance from the camera to the human eye;

[0018] and an image analysis module for complementing the pupil and a data analysis module for obtaining pupil data based on the value of the distance measurement sensor and the complemented pupil image;

[0019] The signal output end of the camera is communicatively connected to the signal input end of the image analysis module, the signal output end of the distance measurement sensor is communicatively connected to the signal input end of the data analysis module, and the signal output end of the image analysis module is communicatively connected to the signal input end of the data analysis module.

[0020] Preferably, the method for the image analysis module to complement the pupil is as follows:

[0021] Step A: Acquire an image, extract the pupil edge, and determine whether the pupil is occluded; if the pupil is occluded, jump to Step B, otherwise jump to Step E;

[0022] Step B: Arbitrarily select three pixel points on the pupil edge to calculate the center and radius of the circle where the pupil is located, and repeat this step until all pixel points on the pupil edge are traversed;

[0023] Step C: Perform least-squares fitting on all the centers and radii obtained in Step B to obtain the center and radius of the fitted circle;

[0024] Step D: Perform variance analysis on the fitted circle and the pupil edge to determine whether the fitting accuracy meets the requirements. If the fitting accuracy does not meet the requirements, adjust the fitting parameters and jump to Step C; if the fitting accuracy meets the requirements, jump to Step E;

[0025] Step E: Transmit the pupil edge data to the data analysis module.

[0026] Preferably, when the variance confidence level between the fitted circle and the pupil edge is greater than 0.95, the fitting accuracy meets the requirements.

[0027] Preferably, in Step A, if the area of the envelope region of the pupil point set < 100 pixels, it is determined that the pupil is occluded; otherwise, it is determined that the pupil is not occluded.

[0028] Preferably, the pupil data obtained by the data analysis module includes the latency period, stable diameter, minimum diameter, maximum acceleration, and maximum speed during the pupil change process.

[0029] Preferably, the method for the data analysis module to obtain pupil data is as follows:

[0030] Step 1: Set filtering parameters to filter the pupil data of the complete stimulation process, and calculate the stable diameter in the normal state and the minimum diameter when the pupil is the smallest;

[0031] Step 2: Calculate the speed and acceleration for two corresponding points on the continuous images, traverse all the diameter data of the entire stimulation process, and obtain the maximum speed and maximum acceleration of the pupil stress change; if there are points where the speed is greater than 10 mm / s for three consecutive times, it is the time when the stress response starts, and record the position data;

[0032] Step 3: Output the pupil data.

[0033] Preferably, it further includes a parameter setting module and a single-chip microcomputer. The signal input end of the single-chip microcomputer is communicatively connected to the signal output ends of the parameter setting module, the camera, and the distance measurement sensor, and the signal output end of the single-chip microcomputer is communicatively connected to the signal input ends of the light stimulation source, the image analysis module, and the data analysis module; through the parameter setting module, instructions can be sent to the single-chip microcomputer to change the light intensity, time, and frequency generated by the light stimulation source.

[0034] Preferably, the light stimulation source further includes three groups of filters for red, green, and blue; the pupil detection device further includes an infrared fill light and a semi-reflective semi-transmissive mirror that reflects the light of the infrared fill light to the pupil area. When the pupil looks straight ahead, the angle between the normal direction of the semi-reflective semi-transmissive mirror and the line of sight is 30° to 60°, and the wavelength of the infrared light emitted by the infrared fill light is 850 nm to 940 nm.

[0035] Preferably, it further includes an acoustic stimulation source whose signal input end is communicatively connected to the signal output end of the single-chip microcomputer, and the acoustic stimulation source can emit a stimulation sound source according to the instructions of the parameter setting module.

[0036] Preferably, the image analysis module, the data analysis module, and the parameter setting module are integrated in computer software, and the computer software is computer software or mobile phone software or embedded software or a web page.

[0037] The advantages of the eyepiece-type automatic pupil light reflex detection device provided by the present invention are as follows: Based on the eyepiece, it is easy to carry and has good compatibility; it provides a variety of light sources and sound sources, facilitating the selection of stimulation types. It meets the requirements of a dark room through a semi-reflective mirror, and fills light for the pupil through an infrared fill light, facilitating the acquisition of clear images; through a distance measurement sensor, the distance between the pupil and the detection device can be accurately obtained to eliminate errors; through a completion algorithm, pupil data can be accurately extracted, and various objective parameters of the light reflex are very suitable for the clinical and research needs of neurology, ophthalmology, and psychiatry. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the composition of the pupil detection device provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] As Figure 1As shown in the figure, an eyepiece type automatic pupillary light reflex detection device includes a camera 1 for acquiring human eye images, a light stimulation source 2 for providing a stimulation light source for the user, a distance measurement sensor 3 for measuring the relative distance from the camera 1 to the human eye, an image analysis module 41 for complementing the pupil image, and a data analysis module 42 for obtaining pupil data based on the value of the distance measurement sensor 3 and the complemented image. When in use, the detection device is placed in front of the human eye, the lens of the camera 1 is aligned with the pupil, the light stimulation source 2 emits light to stimulate the human eye, the camera 1 records the change process of the pupil and sends the image to the image analysis module 41. The image analysis module 41 complements the incomplete pupil image and sends it to the data analysis module 42. At the same time, the distance measurement sensor 3 transmits the collected data to the data analysis module 42. In a preferred embodiment, the distance measurement sensor 3 uses an infrared sensor for ranging, and the directly obtained data is the distance between the distance measurement sensor 3 and the pupil. Since the relative positions of the camera 1 and the distance measurement sensor 3 are already determined, the distance between the pupil and the camera 1 can be calculated using the relative distance between the pupil and the distance measurement sensor 3. Then, the pupil data is obtained through this distance and the complemented image.

[0040] By introducing the distance measurement module 3, the relative distance between the pupil and the camera 1 can be determined for different users respectively, improving the accuracy of the measurement data. In a preferred embodiment, the camera 1 uses an infrared camera to improve the imaging quality.

[0041] Furthermore, the pupil detection device provided in this embodiment also has an acoustic stimulation source 6 to facilitate the study of the effect of sound stimulation on pupil constriction. In order to explore the effect of light of different colors on pupil constriction, the light stimulation source 2 can use a variable light lamp to select the emission color according to needs; alternatively, a filter can be set between the light stimulation source 2 and the pupil. The filter includes three groups of red, green, and blue, so that four colors of red, green, blue, and white can be provided for the user. If other colors are needed, the corresponding filter or a combination of multiple filters can be selected.

[0042] In order to further improve the imaging quality of the camera 1, the pupil detection device also includes an infrared supplementary light (not shown in the figure) and a semi-reflective semi-transmissive lens (not shown in the figure) that reflects the light of the infrared supplementary light to the pupil area. When the pupil looks straight ahead, the included angle between the normal direction of the semi-reflective semi-transmissive lens and the line of sight is 30° - 60°, preferably 45°. The infrared supplementary light provides infrared light with a wavelength of 850 - 940 nm.

[0043] The pupil detection device further includes a parameter setting module 43 and a single-chip microcomputer 5. The signal input end of the single-chip microcomputer 5 is communicatively connected to the signal output ends of the parameter setting module 43, the camera 1, and the distance measurement sensor 3. The signal output end of the single-chip microcomputer 5 is communicatively connected to the signal input ends of the light stimulation source 2, the sound stimulation source 6, the image analysis module 41, and the data analysis module 42. The signal output end of the image analysis module 41 is communicatively connected to the signal input end of the data analysis module 42. The parameter setting module 43 issues instructions to the single-chip microcomputer 5, and the single-chip microcomputer 5 controls the switches of the light stimulation source 2 and the sound stimulation source 6, as well as the light intensity, time, frequency, and corresponding sound parameters according to the instructions.

[0044] The method for the image analysis module 41 to complete the pupil includes the following steps:

[0045] Step A: Obtain an image and extract the pupil edge. If the area of the envelope region of the pupil point set is < 100 pixels, it is considered that the pupil is blocked, and jump to step B; otherwise, jump to step E.

[0046] Step B: Arbitrarily select three pixel points on the pupil edge to calculate the center and radius of the circle where the pupil is located, and repeat this step until all pixel points on the pupil edge are traversed.

[0047] Step C: Perform least squares method fitting on all the centers and radii obtained in step B to obtain the center and radius of the fitting circle.

[0048] Step D: Perform variance analysis on the fitting circle and the pupil edge to determine whether the fitting accuracy meets the requirements. If the fitting accuracy does not meet the requirements, adjust the fitting parameters and jump to step C; if the fitting accuracy meets the requirements, jump to step E.

[0049] Step E: Transmit the pupil edge data to the data analysis module.

[0050] Among them, when the variance confidence level between the fitting circle and the pupil edge is greater than 0.95, it is considered that the fitting accuracy meets the requirements.

[0051] The pupil data obtained by the data analysis module 42 includes the latency period, stable diameter, minimum diameter, maximum acceleration, and maximum speed during the pupil change process, etc. The method for the data analysis module 42 to obtain the above data is as follows:

[0052] Step 1: Set filtering parameters to filter the pupil data of the complete stimulation process, and calculate the stable diameter in the normal state and the minimum diameter when the pupil is the smallest.

[0053] Step 2: For two corresponding points on consecutive images, calculate the velocity and acceleration, traverse all the diameter data during the entire stimulation process, and obtain the maximum velocity and maximum acceleration of the pupil stress change; if there are points where the velocity is greater than 10 mm / s for three consecutive times, it is the time when the stress response starts, and record the data at this position; the stress response latency of the pupil can be obtained by comparing the time when the stimulation is provided and the time when the stress response starts.

[0054] Step 3: Output pupil data.

[0055] The image analysis module 41, data analysis module 42, and parameter setting module 43 can write relevant algorithms into a conventional controller to achieve corresponding functions, or they can be integrated into computer software and processed by calling the processor of the electronic device itself; the computer software is computer software, mobile phone software, embedded software, or web page.

Claims

1. An eyepiece type automatic pupil light reflex detection device, characterized in that: including a camera for acquiring human eye images; a light stimulation source for providing at least one stimulation light source to the user; a distance measurement sensor for measuring the distance from the camera to the human eye; an image analysis module for complementing the pupil and a data analysis module for obtaining pupil data based on the value of the distance measurement sensor and the complemented pupil image; the signal output end of the camera is communicatively connected to the signal input end of the image analysis module, the signal output end of the distance measurement sensor is communicatively connected to the signal input end of the data analysis module, and the signal output end of the image analysis module is communicatively connected to the signal input end of the data analysis module; the method for the image analysis module to complement the pupil is as follows: Step A: Acquire an image, extract the pupil edge, and determine whether the pupil is occluded; If the pupil is occluded, jump to Step B, otherwise jump to Step E; Step B: Arbitrarily select three pixel points on the pupil edge to calculate the center and radius of the circle where the pupil is located, and repeat this step until all pixel points on the pupil edge are traversed; Step C: Perform least squares method fitting on all the centers and radii obtained in Step B to obtain the center and radius of the fitted circle; Step D: Perform variance analysis on the fitted circle and the pupil edge to determine whether the fitting accuracy meets the requirements. If the fitting accuracy does not meet the requirements, adjust the fitting parameters and jump to Step C; If the fitting accuracy meets the requirements, jump to Step E; Step E: Transmit the pupil edge data to the data analysis module; When the variance confidence level between the fitted circle and the pupil edge is greater than 0.95, the fitting accuracy meets the requirements; In Step A, if the area of the envelope region of the pupil point set is < 100 pixels, it is determined that the pupil is occluded; Otherwise, it is determined that the pupil is not occluded.

2. The automatic detection device for pupillary light reflex of an eyepiece type according to claim 1, characterized in that: The pupil data obtained by the data analysis module includes the latency, stable diameter, minimum diameter, maximum acceleration, and maximum speed during the pupil change process.

3. The automatic pupillary light reflex detection device of the eyepiece type according to claim 2, characterized in that: The method for the data analysis module to obtain pupil data is as follows: Step 1: Set filtering parameters to filter the pupil data of the complete stimulation process, and calculate the stable diameter in the normal state and the minimum diameter when the pupil is smallest; Step 2: Calculate the speed and acceleration for two corresponding points on the consecutive images, traverse all the diameter data of the entire stimulation process, and obtain the maximum speed and maximum acceleration of the pupil stress change; If there are three consecutive points with a speed greater than 10 mm / s, it is the time when the stress response starts, and record the position data; Step 3: Output the pupil data.

4. The automatic detection device for pupillary light reflex of an eyepiece type according to claim 1, characterized in that: It further includes a parameter setting module and a single-chip microcomputer. The signal input end of the single-chip microcomputer is communicatively connected to the signal output ends of the parameter setting module, the camera, and the distance measurement sensor. The signal output end of the single-chip microcomputer is communicatively connected to the signal input ends of the light stimulation source, the image analysis module, and the data analysis module; Through the parameter setting module, instructions can be sent to the single-chip microcomputer to change the light intensity, time, and frequency generated by the light stimulation source.

5. The automatic detection device for pupillary light reflex of an eyepiece type according to claim 1, characterized in that: The light stimulation source further includes three groups of filters for red, green, and blue; the pupil detection device further includes an infrared supplementary light and a semi-reflective and semi-transmissive lens that reflects the light of the infrared supplementary light to the pupil area. When the pupil faces forward, the included angle between the normal direction of the semi-reflective and semi-transmissive lens and the line of sight is 30° to 60°, and the wavelength of the infrared light emitted by the infrared supplementary light is 850 nm to 940 nm.

6. An eyepiece type automatic pupillary light reflex detection device according to claim 4, characterized in that: It further includes an acoustic stimulation source whose signal input end is communicatively connected to the signal output end of the single-chip microcomputer, and the acoustic stimulation source can emit a stimulation sound source according to the instruction of the parameter setting module.

7. An eyepiece type automatic pupillary light reflex detection device according to claim 3, characterized in that: The image analysis module, the data analysis module, and the parameter setting module are integrated in computer software, and the computer software is computer software, mobile phone software, embedded software, or a web page.

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