A pupil parameter measuring instrument and method thereof

Abstract

This invention discloses a pupil parameter measuring instrument and method, including a pupil pen and a back-end analysis and processing platform. The pen's head, middle, and tail are detachably connected. A miniature infrared camera is located at the center of the pen's front end. Several infrared supplementary lights, a visible light source, and a distance sensor are located at the front end of the pen's head. The miniature infrared camera, infrared supplementary lights, visible light source, and distance sensor are all electrically connected to a flexible PCB board. A microcontroller and a motor are located within the middle of the pen, and a display screen is located on the pen's housing. A power module is located within the tail of the pen. The microcontroller is electrically connected to the flexible PCB board, the motor, and the display screen. The pupil pen is connected to the back-end analysis and processing platform via a wireless communication module. This invention provides a pupil parameter measuring instrument and method that effectively reduces the subjective errors caused by traditional visual examination through multi-dimensional quantitative monitoring of pupil diameter, constriction rate, and constriction speed.

Description

Technical Field

[0001] This invention relates to the field of pupil measurement technology, and in particular to a pupil parameter measuring instrument and method. Background Technology

[0002] The pupillary light reflex is one of the standards in neurological examinations. Its diameter, symmetry, and sensitivity to light are indicators of pathological states such as increased intracranial pressure, precursors to brain herniation, central nervous system damage, and drug poisoning. However, existing pupillary measurement methods have the following limitations in clinical application:

[0003] (1) The most commonly used tool in clinical practice is still the ordinary visible light flashlight combined with naked eye observation; the estimation error is large: doctors rely on naked eye and clinical experience to make estimations, and are easily affected by the angle, light intensity and the observer's experience; in addition, using visible white light to stimulate reflection will cause the pupil to contract rapidly, making it impossible to measure the pupil diameter of the patient in a natural resting state, and thus unable to obtain the important reference data of pupil contraction rate.

[0004] (2) Most existing pupil pens are single snapshot measurements, and the data is recorded in paper or separate electronic medical records. They cannot automatically generate continuous dynamic trends. The occurrence of critical illnesses such as brain herniation is often accompanied by a slow decrease in pupil constriction rate (CH%). This change process needs to be continuously recorded to be captured. Medical staff have a high workload, and the non-systematic single recording makes it more difficult to track and analyze pupil data. Summary of the Invention

[0005] In view of this, the present invention proposes a pupil parameter measuring instrument and method thereof.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A pupil parameter measuring instrument and method thereof includes a pupil pen and a back-end analysis and processing platform. The pupil pen has a detachable head, middle, and tail. A miniature infrared camera is located at the center of the front end of the head. The front end of the head also has several infrared fill lights, a visible light source, and a distance sensor. The miniature infrared camera, infrared fill lights, visible light source, and distance sensor are all electrically connected to a flexible PCB board. The flexible PCB board is located inside the pupil pen. A microcontroller and a motor are located in the middle of the pen, and a display screen is located on the middle shell of the pen. A power module is located in the tail. The power module is electrically connected to the flexible PCB board, the microcontroller, the motor, and the display screen. The microcontroller is electrically connected to the flexible PCB board, the motor, and the display screen. The pupil pen is connected to the back-end analysis and processing platform via a wireless communication module.

[0008] Furthermore, the pen tip, middle part, and tail part of the pupil pen are threadedly connected to each other.

[0009] Furthermore, there are four infrared fill lights; the four infrared fill lights are evenly arranged circumferentially on the outside of the miniature infrared camera.

[0010] Furthermore, the visible light source has a support along the edge of its light source end face; the support has a hole for the visible light source to pass through; and a diffuser is fixedly provided on the outside of the hole in the support.

[0011] Furthermore, the motor is an X-axis linear motor.

[0012] Furthermore, the miniature infrared camera is an OmniVision OVM6946; the infrared fill light is an Osram SFH4715S.

[0013] Furthermore, the ranging sensor is a STMicroelectronics VL53L1X, and the microcontroller is an STM32H743.

[0014] The present invention also provides a measurement method for a pupil parameter measuring instrument, comprising the following steps:

[0015] S1: The operator holds the pupil pen and moves it toward the patient's eye, and the distance sensor is activated to perform real-time distance measurement; when the distance between the pupil pen's camera and the patient's pupil is appropriate, the motor vibrates;

[0016] S2: In the first stage, the patient's eyes are opened, several infrared supplementary lights are turned on, and a miniature infrared camera is working to record the pupil size of the patient under the current environment; In the second stage, the patient's eyes are opened, a visible light source is turned on, and a miniature infrared camera is working to record the pupil size of the patient under the current visible light source stimulation under the state of pupil constriction.

[0017] S3: The microcontroller processes the captured image in real time, runs the Starburst algorithm to extract pupil edge feature points and performs ellipse fitting; then, combined with the object distance information fed back by the range sensor, it calculates the actual millimeter diameter of the pupil.

[0018] The microcontroller stores the actual millimeter diameter of the pupil and transmits the data to the display screen for display.

[0019] S4: The actual millimeter diameter data of the pupil is uploaded to the back-end processing and analysis platform through the wireless communication module, which centrally stores the pupil diameter data of multiple patients and monitors abnormalities in the pupil size of patients in real time.

[0020] Furthermore, the appropriate distance between the miniature infrared camera of the pupil pen and the patient's pupil is 3 to 10 cm.

[0021] Furthermore, S3 specifically includes the following steps:

[0022] S31: The original image is acquired by a miniature infrared camera, retaining only the ROI area where the pupil is located;

[0023] The microcontroller performs binarization based on a dynamic threshold to separate the pupil region from the iris; the microcontroller obtains the highest grayscale value G of the ROI region. max and lowest gray level G min The microcontroller locates the low grayscale set where the grayscale value G is less than the dynamic threshold T through global pixel scanning, calculates the geometric centroid coordinates (x0, y0) of the low grayscale set, and defines it as the initial seed point. The seed point serves as the starting origin for subsequent starburst ray detection.

[0024] Dynamic threshold T=G min +(G max -G min )×W; W is the grayscale weight adjustment factor, and the range of W is 0.2 to 0.4;

[0025] S32: Starting from the initial centroid reference point, N probe rays are projected outward along the circumferential direction;

[0026] Detecting changes in pixel grayscale function along the ray direction, when pixel grayscale function d f / d r If the value is greater than the edge response threshold, it is identified as a boundary point and removed from the point set: d f d is the derivative of the grayscale value. r The derivative of the distance the ray travels;

[0027] S33: Using the retained effective edge coordinates, circle fitting calculation is performed using the linear least squares method to obtain the pixel radius R of the pupil at the current moment;

[0028] The actual diameter of the pupil = (2R × μ × D) / f;

[0029] Where R is the pixel radius of the pupil, μ is the physical size of a single pixel unit of the image sensor, D is the physical distance from the device to the cornea that is fed back in real time by the ranging sensor, and f is the effective focal length of the optical lens of the infrared miniature camera.

[0030] Compared with existing technologies, the beneficial effects of this invention are:

[0031] (1) The pupil parameter measuring instrument and method provided by the present invention realizes the objective auxiliary diagnosis of critical illnesses such as intracranial hypertension, cerebral herniation precursor, acute poisoning and brainstem injury by multi-dimensional quantitative monitoring of pupil diameter, contraction rate and contraction speed, and effectively reduces the subjective error caused by traditional visual examination.

[0032] (2) The pupil parameter measuring instrument and method provided by the present invention can measure the patient’s sensitivity to light reflection. If the pupil contraction rate is large, the patient’s pupil is sensitive to light reflection; if the pupil contraction rate is small, the patient’s pupil is sluggish to light reflection; if the pupil contraction rate is close to 0, the patient’s light reflection disappears.

[0033] (3) Traditional pupil diameter estimation is highly susceptible to the influence of physician experience, fatigue level, and patient iris color (dark irises have low contrast). This solution uses a microcontroller for unified processing, ensuring the reproducibility of measurement results;

[0034] (4) The pupil parameter measuring instrument and method provided by the present invention can not only calculate the diameter of the pupil, but also calculate key parameters such as the roundness and center displacement of the pupil. These subtle morphological changes are completely imperceptible to the naked eye but have clinical significance. Attached Figure Description

[0035] Figure 1 A perspective view of the pupil pen provided in an embodiment of the present invention;

[0036] Figure 2 This is a left view of the pupil pen provided in an embodiment of the present invention;

[0037] Figure 3 An exploded view of the pupil pen provided in an embodiment of the present invention;

[0038] Figure 4 A perspective view of the middle part of the pupil pen provided in an embodiment of the present invention;

[0039] Figure 5 This is a right view of the middle part of the pupil pen provided in an embodiment of the present invention;

[0040] Figure 6 A perspective view of the tip of a pupil pen provided in an embodiment of the present invention.

[0041] In the diagram: 1. Pupil pen; 101. Pen tip; 102. Pen middle; 103. Pen tail; 2. Miniature infrared camera; 3. Infrared fill light; 4. Visible light source; 5. Distance sensor; 6. Flexible PCB board; 7. Microcontroller; 8. Transparent glass screen; 9. Display screen; 10. Motor; 11. Diffuser. Detailed Implementation

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0043] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "pen tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] Example

[0046] like Figure 1-6 As shown, a pupil parameter measuring instrument includes a pupil pen 1 and a back-end analysis and processing platform; the pen tip 101, the pen middle 102, and the pen tail 103 of the pupil pen 1 are threadedly connected to each other.

[0047] The pupil pen 1 has a miniature infrared camera 2 at the center of the tip 101. The miniature infrared camera 2 is an OmniVision OVM6946.

[0048] The tip 101 of the pupil pen 1 is equipped with four infrared fill lights 3, which are evenly arranged circumferentially on the outside of the miniature infrared camera 2. The infrared fill lights 3 are Osram SFH4715S models.

[0049] The pupil pen 1 has a visible light source 4 at its tip 101, located above the tip 101. The visible light source 4 has a support along its edge; the support has a hole for the visible light source 4 to pass through; a diffuser is fixed to the outside of the hole. The diffuser converts the point light source into a uniform area light source. The light from the visible light source becomes diffused and softer, making it more tolerable for patients and improving their cooperation.

[0050] The pupil pen 1 has a distance sensor 5 at the front end of the pen tip 101; the distance sensor 5 is located on the lower edge of the front end of the pen tip 101 of the pupil pen 1. The distance sensor 5 is a VL53L1X from STMicroelectronics.

[0051] The wiring terminals of the miniature infrared camera 2, several infrared fill lights 3, visible light source 4, and distance sensor 5 are all electrically connected to the flexible PCB board 6; the flexible PCB board 6 is located inside the pen tip 101 of the pupil pen 1.

[0052] The pupil pen 1 has a microcontroller 7 inside the middle part 102. The microcontroller 7 is an STM32H743.

[0053] The pupil pen 1 has an X-axis linear motor inside its central part 102. A display screen 9 is mounted on the housing of the central part 102 of the pupil pen 1. Specifically, a transparent glass screen 8 is mounted on the housing of the central part 102 of the pupil pen 1, and the display screen 9 is fixedly mounted on the inner side of the transparent glass screen 8. A power module is located inside the tail part 103 of the pupil pen 1.

[0054] The power module is electrically connected to the miniature infrared camera 2, flexible PCB board 6, microcontroller 7, motor 10, and display screen 9, providing power to each component. The microcontroller 7 is electrically connected to the flexible PCB board 6, X-axis linear motor, and display screen 9. The output of the ranging sensor 5 is electrically connected to the input of the microcontroller 7, and the output of the microcontroller 7 is electrically connected to the miniature infrared camera 2, four infrared fill lights 3, visible light source 4, X-axis linear motor, and the input of the display screen 9. The pupil pen 1 is connected to the background analysis and processing platform via a wireless communication module.

[0055] The present invention also provides a measurement method for a pupil parameter measuring instrument, comprising the following steps:

[0056] S1: The operator holds the pupil pen 1 and moves it toward the patient's eye. The distance sensor 5 is activated to perform real-time distance measurement. When the distance between the camera of the pupil pen 1 and the patient's pupil is 5cm, the X-axis linear motor vibrates.

[0057] S2: In the first stage, the patient's eyes are opened, four infrared supplementary lights 3 are turned on, and the miniature infrared camera 2 works to record the patient's pupil size in the resting state under the current environment; In the second stage, the patient's eyes are opened, the visible light source 4 is turned on, and the miniature infrared camera 2 works to record the patient's pupil size in the constricted state under the stimulation of the current visible light source.

[0058] S31: Obtain raw data from the miniature infrared camera 2, retaining only the ROI area where the pupil is located;

[0059] Since the pupil appears dark black (low grayscale value) under infrared light, the microcontroller 7 performs binarization processing based on a dynamic threshold to separate the pupil region from the iris; the microcontroller 7 obtains the highest grayscale value G of the ROI region. max and lowest gray level G min The microcontroller 7 locates the low grayscale set whose grayscale value G is less than the dynamic threshold T through global pixel scanning, calculates the geometric centroid coordinates (x0, y0) of the low grayscale set, defines it as the initial seed point, and uses the seed point as the starting origin of subsequent starburst ray detection.

[0060] Dynamic threshold T=G min +(G max -G min )×W; W is the grayscale weight adjustment factor, and the range of W is 0.2 to 0.4;

[0061] S32: Starting from the initial centroid reference point, N probe rays are projected outward along the circumferential direction;

[0062] Detecting changes in pixel grayscale function along the ray direction, when pixel grayscale function d f / d r Points exceeding the edge response threshold are identified as boundary points and removed from the set of fitted points: d f d is the derivative of the grayscale value. r The derivative of the distance the ray travels;

[0063] S33: Using the retained effective edge coordinates, circle fitting calculation is performed using the linear least squares method to obtain the pixel radius R of the pupil at the current moment;

[0064] The actual diameter of the pupil = (2R × μ × D) / f;

[0065] Where R is the pixel radius of the pupil, μ is the physical size of a single pixel unit of the image sensor, D is the physical distance from the device to the cornea that is fed back in real time by the ranging sensor 5, and f is the effective focal length of the optical lens of the infrared miniature camera.

[0066] S4: The actual millimeter diameter data of the pupil is uploaded to the back-end processing and analysis platform through the wireless communication module, which centrally stores the pupil diameter data of multiple patients and monitors abnormalities in the pupil size of patients in real time.

[0067] The pupillary contraction rate of this scheme = (D) rest -D min ) / D rest ; where D rest The resting pupil diameter calculated in the first stage is the average physical diameter of the pupil measured under infrared illumination before white light excitation; D minThis represents the minimum pupil diameter reached during the pupil constriction process in the second stage after white light stimulation.

[0068] If the pupillary contraction rate is large, the patient's pupil is sensitive to light reflex; if the pupillary contraction rate is small, the patient's pupil is sluggish to light reflex; if the pupillary contraction rate is close to 0, the patient's light reflex disappears.

[0069] This protocol enables objective auxiliary diagnosis of critical conditions such as intracranial hypertension, precursors to brain herniation, acute poisoning, and brainstem injury through multi-dimensional quantitative monitoring of pupil diameter, contraction rate, and contraction speed, effectively reducing the subjective errors caused by traditional visual examination.

[0070] Traditional pupil pens use visible white light to simultaneously align with and observe the pupil. Because white light induces strong pupil contraction, it's difficult for doctors to observe the true size of the pupil in its natural (resting) state. This solution uses 850nm infrared illumination, which is completely imperceptible to the human eye. A miniature infrared camera 2 can clearly capture images without interfering with the natural state of the pupil.

[0071] The pupillary light reflex is a dynamic constriction process. By collecting the pupil diameter in its natural state (resting state) and the pupil diameter under visible light, the pupil constriction rate can be calculated. The constriction rate helps to more accurately determine the severity of certain conditions in patients, such as the degree of nerve damage.

[0072] In this scheme, the visible light source 4 can be turned on for a short time as a stimulation signal. This avoids the discomfort to the patient's eyes caused by the traditional pupil pen 1 shining light directly on the eye for a long time, thus improving the patient's comfort during pupil examination and increasing cooperation.

[0073] Infrared imaging is not affected by dim lighting in the examination room. Accurate measurements can be completed without turning on the indoor lights when the lighting is dim or during nighttime ward rounds, without disturbing the patient's rest.

[0074] The setting of the ranging sensor 5 ensures that when the distance between the ranging sensor 5 and the patient is within an appropriate range, the miniature infrared camera 2 can be activated to take pictures, avoiding blurry focus, ensuring that the acquired image is in the best imaging quality, ensuring that the acquired pupil image is clear, and thus ensuring the accuracy of the final calculated pupil data.

[0075] Traditional pupil diameter estimation is highly susceptible to influences from physician experience, fatigue levels, and patient iris color (dark irises have low contrast). This solution uses a microcontroller 7 for standardized processing, ensuring reproducibility of measurement results, even when different physicians measure the same patient's pupils.

[0076] This method can not only calculate the diameter of the pupil, but also key parameters such as the roundness and center displacement of the pupil. These subtle morphological changes are completely imperceptible to the naked eye but have clinical significance.

[0077] The display screen 9 on this pupil pen 1 allows doctors to instantly obtain pupil diameter values, saving time on manual reading and recording. Especially in emergency situations, the second-level data feedback can quickly assist in decision-making.

[0078] The backend analysis platform connects fragmented measurement points into lines, storing pupil data throughout a patient's hospitalization and automatically generating trend curves or charts. All data is automatically synchronized, ensuring the objectivity and completeness of medical records. This provides standardized data support for subsequent teaching, research, and medical quality control, and also promptly issues alerts when abnormalities occur in the patient's pupil size data.

[0079] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pupil parameter measuring instrument, comprising a pupil pen (1) and a back-end analysis and processing platform; characterized in that, The pen tip (101), middle part (102), and tail part (103) of the pupil pen (1) are detachably connected to each other; a miniature infrared camera (2) is provided at the center of the front end of the pen tip (101) of the pupil pen (1); several infrared fill lights (3), visible light sources (4), and distance sensors (5) are provided at the front end of the pen tip (101) of the pupil pen (1); the miniature infrared camera (2), several infrared fill lights (3), visible light sources (4), and distance sensors (5) are all electrically connected to the flexible PCB board (6); the flexible PCB board (6) is located inside the pupil pen (1). The pupil pen (1) has a micro controller (7) and a motor (10) in the middle part (102) of the pen, and a display screen (9) on the shell of the middle part (102) of the pupil pen (1); a power module is provided in the tail part (103) of the pupil pen (1); the power module is electrically connected to the flexible PCB board (6), the micro controller (7), the motor (10), and the display screen (9) respectively; the micro controller (7) is electrically connected to the flexible PCB board (6), the motor (10), and the display screen (9) respectively; the pupil pen (1) is connected to the background analysis and processing platform through a wireless communication module.

2. The pupil parameter measuring instrument according to claim 1, characterized in that, The pen tip (101), pen middle (102), and pen tail (103) of the pupil pen (1) are threaded together.

3. The pupil parameter measuring instrument according to claim 1, characterized in that, There are four infrared fill lights (3); the four infrared fill lights (3) are evenly arranged circumferentially on the outside of the miniature infrared camera (2).

4. The pupil parameter measuring instrument according to claim 1, characterized in that, The visible light source (4) has a support on the edge of its light source end face; the support has a hole for the visible light source (4) to pass through; a diffuser (11) is fixed on the outside of the hole of the support.

5. A pupil parameter measuring instrument according to claim 1, characterized in that, The motor (10) is an X-axis linear motor.

6. The pupil parameter measuring instrument according to claim 1, characterized in that, The miniature infrared camera (2) is an OVM6946 from OmniVision; the infrared fill light (3) is an SFH4715S from Osram.

7. A pupil parameter measuring instrument according to claim 1, characterized in that, The ranging sensor (5) is a STMicroelectronics VL53L1X; the microcontroller (7) is an STM32H743.

8. A method for measuring pupil parameters using a pupil parameter measuring instrument as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: The operator holds the pupil pen (1) and moves it toward the patient's eye. The distance sensor (5) is turned on to perform real-time distance measurement. When the distance between the camera of the pupil pen (1) and the patient's pupil is appropriate, the motor (10) vibrates. S2: In the first stage, the patient's eyes are opened, several infrared supplementary lights (3) are lit, and the miniature infrared camera (2) works to record the pupil size of the patient in the current environment; In the second stage, the patient's eyes are opened, the visible light source (4) is lit, and the miniature infrared camera (2) works to record the pupil size of the patient in the current visible light source stimulation. S3: The microcontroller processes the captured image in real time, runs the Starburst algorithm to extract pupil edge feature points and performs ellipse fitting; then, combined with the object distance information fed back by the distance sensor (5), the actual millimeter diameter of the pupil is calculated; The microcontroller (7) stores the actual millimeter diameter of the pupil and transmits the actual diameter data of the pupil to the display screen (9) for display. S4: The actual millimeter diameter data of the pupil is uploaded to the back-end processing and analysis platform through the wireless communication module, which centrally stores the pupil diameter data of multiple patients and monitors abnormalities in the pupil size of patients in real time.

9. The measurement method of a pupil parameter measuring instrument according to claim 8, characterized in that, The appropriate distance between the miniature infrared camera (2) of the pupil pen (1) and the patient's pupil is 3 to 10 cm.

10. The measurement method of a pupil parameter measuring instrument according to claim 8, characterized in that, S3 specifically includes the following steps: S31: The original image is acquired by the miniature infrared camera (2), and only the ROI area where the pupil is located is retained; The microcontroller (7) performs binarization based on a dynamic threshold to separate the pupil region from the iris; the microcontroller (7) obtains the highest gray level G of the ROI region. max and lowest gray level G min The microcontroller (7) locates the low grayscale set whose grayscale value G is less than the dynamic threshold T by global pixel scanning, calculates the geometric centroid coordinates (x0, y0) of the low grayscale set, defines it as the initial seed point, and the seed point serves as the starting origin of subsequent starburst ray detection. Dynamic threshold T=G min +(G max -G min )×W; W is the grayscale weight adjustment factor, and the range of W is 0.2 to 0.4; S32: Starting from the initial centroid reference point, N probe rays are projected outward along the circumferential direction; Detecting changes in pixel grayscale function along the ray direction, when pixel grayscale function d f / d r If the value is greater than the edge response threshold, it is identified as a boundary point and removed from the point set: d f d is the derivative of the grayscale value. r The derivative of the distance the ray travels; S33: Using the retained effective edge coordinates, circle fitting calculation is performed using the linear least squares method to obtain the pixel radius R of the pupil at the current moment; The actual diameter of the pupil = (2R × μ × D) / f; Where R is the pixel radius of the pupil, μ is the physical size of a single pixel unit of the image sensor, D is the physical distance from the device to the cornea fed back in real time by the ranging sensor (5), and f is the effective focal length of the optical lens of the infrared miniature camera.

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