Portable non-corneal contact intraocular pressure measuring device and method

Abstract

The invention relates to the technical field of intraocular pressure measurement, and aims to solve the problems that a contact type intraocular pressure measuring head of an existing intraocular pressure meter is in direct contact with a cornea, the risk of corneal epithelium injury and infection exists, the measurement result is influenced by the thickness and curvature of the cornea, the requirement on an operator is high, the cooperation of a subject is needed, and the process is tedious. The invention provides a portable non-corneal contact intraocular pressure measuring device and method.The portable non-corneal contact intraocular pressure measuring device comprises a detection mechanism assembly, a shell, a control system circuit and a fixing band, the device is fixed to the head of a subject through the fixing band, and the subject receives measurement when the eyes are closed; the push rod and the strain gauge are used for completing intraocular pressure measurement by making contact with the eyelids rather than directly making contact with the surfaces of eyeballs, measurement data of the intraocular pressure are obtained through signal changes generated by deformation of the strain gauge covering the surface of the flexible film, the problem that a detection result is inaccurate due to blinking of a subject is solved, and operation is easy.

Description

Technical Field

[0001] The present invention relates to the technical field of intraocular pressure measurement, and in particular to a portable non-corneal contact intraocular pressure measurement device and method. Background Art

[0002] Intraocular pressure is the pressure inside the eyeball. It is the balanced pressure exerted by the contents of the eye on the wall of the eyeball. Normal intraocular pressure is within a certain range, which can maintain the good function of the optic nerve and ensure normal vision. Normal intraocular pressure is stable within a certain range to maintain the normal shape of the eyeball. The range of normal intraocular pressure is 1.33~2.80kPa (10~21mmHg). Low intraocular pressure, like high intraocular pressure, is a pathological state.

[0003] At present, common tonometers include contact and non-contact tonometers, both of which are based on measuring the cornea's response to external forces to indirectly infer intraocular pressure. The contact tonometer uses a pressure gauge with a specific area to gently touch the corneal surface. When the pressure gauge flattens the cornea to a certain area, the required force is the intraocular pressure value. However, the pressure gauge of the contact tonometer directly contacts the cornea, which poses a risk of corneal epithelial damage and infection; and the measurement results are affected by corneal thickness and curvature. For patients with corneal edema, corneal opacity or uneven corneal surface, the measurement results may be inaccurate; in addition, the use of the contact tonometer is also relatively cumbersome, and the operator's technical requirements are high when using it. The patient also needs to be able to cooperate with the measurement process, and the equipment needs to be disinfected after each use to avoid cross infection.

[0004] For non-contact tonometer, its principle is to use a controllable air pulse to quickly flatten the center of the cornea, and at the same time send a beam of light to the cornea to measure the light reflection of the corneal flattening area. When the corneal flattening area reaches a certain diameter, the air pressure at this time is the intraocular pressure value. However, the stability of its measurement depends largely on the contact area between the air pulse and the cornea, and the contact area is usually very small; if the patient blinks or other actions due to nervousness during the measurement process, it may affect the accuracy of the measurement results; environmental conditions such as temperature and humidity may also have a certain impact on the measurement results of the non-contact tonometer. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a portable non-corneal contact intraocular pressure measurement device and method, which allows the subject to be measured with eyes closed, and uses a push rod and a strain gauge to complete the intraocular pressure measurement by contacting the eyelids instead of directly touching the surface of the eyeball, thereby overcoming the problem of inaccurate test results caused by the subject's blinking, and can also relieve the subject's nervousness when measuring intraocular pressure. In addition, the present invention does not need to directly contact the cornea when used, eliminating the risk of corneal epithelial damage and infection, and is clean and hygienic.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A portable non-corneal contact intraocular pressure measuring device comprises a shell, a control system circuit and two sets of detection mechanism components. The shell is a hollow cavity structure, two ends of a fixing belt are respectively connected to two ends of the shell, and two through holes are provided on the side of the shell facing the fixing belt; the two sets of detection mechanism components are respectively placed at positions where the through holes are provided inside the shell, and the driving mechanism and control system circuit of the detection mechanism components are placed inside the shell.

[0008] Furthermore, the detection mechanism assembly includes a strain gauge and a flexible film, the flexible film covers the through hole of the shell, the strain gauge is annular in structure, the strain gauge is attached to the side of the flexible film facing the inside of the shell cavity, and the center of the strain gauge coincides with the center of the through hole.

[0009] Furthermore, the driving mechanism includes a voice coil motor and a push rod. The voice coil motor includes a coil and a permanent magnet. The coil is sleeved on the permanent magnet. The push rod is fixedly connected to the center position of the end of the voice coil motor, and the end of the push rod is a hemispherical structure. The end of the push rod faces the through hole of the outer shell. After the coil is energized, the push rod is driven to move by using the current and the permanent magnet.

[0010] Furthermore, the control system circuit includes a pressure sensor module, an analog-to-digital conversion circuit and a controller. The first signal output end of the controller in the control system circuit is connected to the signal input end of the driving mechanism, the second signal output end is connected to the wireless communication transmitter, and the first signal input end of the controller is connected to the signal output end of the strain gauge through the pressure sensor module and the analog-to-digital conversion circuit.

[0011] A non-corneal contact intraocular pressure measurement method, based on the above-mentioned portable non-corneal contact intraocular pressure measurement device, obtains intraocular pressure measurement data by using the signal change generated by the deformation of the strain gauge covered on the surface of the flexible film, and specifically includes the following steps:

[0012] Step 1. Confirm the integrity of the portable non-corneal contact intraocular pressure measuring device, and use a fixing belt to fix the portable non-corneal contact intraocular pressure measuring device on the head of the subject, with the two through holes of the shell aligned with the two eyes of the subject respectively;

[0013] Step 2. After the subject closes his eyes, the portable non-corneal contact intraocular pressure measuring device is started. At this time, the strain gauge produces initial deformation due to the spherical structure of the eyeball and cornea, and the strain gauge outputs an initial deformation signal;

[0014] Step 3. The voice coil motor pushes the push rod toward the flexible film under the action of the current of the control system circuit and its own magnetic field. When the push rod contacts the flexible film, the strain gauge generates secondary deformation, and the deformation signal output by the strain gauge changes. Under the action of the push rod, the deformation signal output by the strain gauge continues to change until the push rod cannot move. At this time, the pressure generated by the deformation of the strain gauge is the intraocular pressure measurement value. The pressure at this time determined by the deformation signal output by the strain gauge is the intraocular pressure measurement value of the subject;

[0015] Step 4. The push rod returns to the initial detection position to complete the measurement, and the intraocular pressure measurement value obtained in step 3 is compared with the data of the normal intraocular pressure range to determine whether the obtained measurement value is within the normal intraocular pressure range.

[0016] In summary, compared with the prior art, the invention has the following beneficial effects:

[0017] (1) The present invention has a simple structure, light weight, and the overall device is easy to maintain. When the subject wears the device, the pressure on the head is small, and the subject obtains a better use experience;

[0018] (2) The present invention adopts a contact detection method in which the push rod contacts the eyelid during the process of measuring intraocular pressure. Compared with the traditional contact detection method in which the push rod contacts the cornea, the present invention does not need to make direct contact with the cornea during the detection process, and adopts a closed-eye measurement method, thereby overcoming the problem of inaccurate detection results caused by the subject's blinking. It is also unnecessary to replace a new probe every time a test is performed, thereby saving the use cost and simplifying the operation steps.

[0019] (3) The present invention adopts a contact detection method of pressing step by step, and the detection result can be obtained by measuring once. The device of the present invention does not contact the surface of the eyeball during the entire detection process, and also eliminates the nervousness of the subject. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an intraocular pressure detection flow chart of the present invention;

[0021] Figure 2 It is a schematic diagram of the device structure of the present invention;

[0022] Figure 3 is a schematic diagram of a detection mechanism assembly in the device of the present invention;

[0023] Figure 4 is a radial cross-sectional view of the device of the present invention;

[0024] Figure 5 It is a schematic diagram of the installation position of the driving mechanism in the device of the present invention;

[0025] Figure 6 It is a structural schematic diagram of the driving mechanism of the present invention;

[0026] Figure 7 is a structural diagram of the coil of the driving mechanism of the present invention;

[0027] Figure 8 It is a structural diagram of the permanent magnet of the driving mechanism of the present invention.

[0028] In the figure: housing 1, fixing belt 2, driving mechanism 3, voice coil motor 31, coil 311, permanent magnet 312, push rod 32, detection mechanism assembly 4, strain gauge 41, flexible film 42, control system circuit 5. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] like Figures 2 to 8 As shown, the present invention discloses a portable non-corneal contact intraocular pressure measuring device, comprising a housing 1, a fixing belt 2, a control system circuit 5 and two sets of detection mechanism components 4. The housing 1 is a hollow cavity structure, and the two ends of the fixing belt 2 are respectively connected to the two ends of the housing 1. The fixing belt 2 is also provided with a mesh auxiliary fixing belt, such as Figure 3 As shown, the subject fixes the device on the head through a fixing belt 2 connected to the shell 1; the shell 1 is provided with two through holes on the side facing the fixing belt 1, and the outer wall of the shell 1 on the side where the through holes are located is in an arc-shaped structure that fits the face of the subject, and the through holes are set to an elliptical shape, which is ergonomic; two groups of detection mechanism components 4 are respectively placed at the positions where the through holes are provided inside the shell 1, and the driving mechanism 3 and the control system circuit 5 of the detection mechanism components 4 are placed inside the shell 1.

[0031] The detection mechanism assembly 4 includes a strain gauge 41 and a flexible film 42. The flexible film 42 covers the through hole of the shell 1. The strain gauge 41 has an annular structure. The strain gauge 41 is attached to the side of the flexible film 42 facing the inside of the cavity of the shell 1. The center of the strain gauge 41 coincides with the center of the through hole, so that the deformation of the strain gauge 41 is balanced at all locations when deformation occurs.

[0032] The driving mechanism 3 includes a voice coil motor 31 and a push rod 32. The voice coil motor 31 includes a coil 311 and a permanent magnet 312. The coil 311 is sleeved on the permanent magnet 312. The push rod 32 is fixedly connected to the center position of the end of the voice coil motor 31, and the end of the push rod 32 is a hemispherical structure. The end of the push rod 32 faces the through hole of the shell 1. After the coil 311 is energized, the current and the permanent magnet 312 are used to drive the push rod 32 to move. During the advancement process, the push rod 32 causes the flexible film 42 and the strain gauge 41 to produce recoverable deformation, and the strain gauge 41 outputs a deformation signal.

[0033] The control system circuit 5 includes a pressure sensor module, an analog-to-digital conversion circuit and a controller. The first signal output terminal of the controller in the control system circuit 5 is connected to the signal input terminal of the driving mechanism 3, and the second signal output terminal is connected to the wireless communication transmitter. The first signal input terminal of the controller is connected to the signal output terminal of the strain gauge 41 through the pressure sensor module and the analog-to-digital conversion circuit. The control system circuit 5 realizes the travel control of the push rod 32 during the detection process through the driving mechanism 3, and determines the moment when the push rod 32 stops advancing through the signal change of the strain gauge 41.

[0034] The control system circuit 5 includes a pressure sensor module that converts a pressure signal into an electrical signal, an amplifier and a filter inside, and a signal conditioning module that performs gain, filtering, and amplification processing on the input signal to optimize the signal; an analog-to-digital conversion chip (ADC) and a controller. In this embodiment, the controller uses an STM32 single-chip microcomputer, and the wireless communication transmitter uses a Bluetooth signal transmitter. When the portable non-corneal contact intraocular pressure measurement device is started, the controller on the control system circuit 5, that is, the STM32 single-chip microcomputer, sends a control signal to start the driving mechanism 3. After the driving mechanism 3 deforms the strain gauge 41 through the push rod 32, the strain gauge 41 sends a feedback signal. The pressure sensor module on the control system circuit 5 collects the analog signal fed back by the strain gauge 41, and the ADC chip converts the analog signal into a digital signal. The generated digital signal is processed by the STM32 single-chip microcomputer and transmitted to the host computer through the Bluetooth module to complete the measurement of intraocular pressure and the transmission of intraocular pressure measurement data.

[0035] like Figure 1 As shown, the present invention also discloses a non-corneal contact intraocular pressure measurement method, based on the above-mentioned portable non-corneal contact intraocular pressure measurement device, using the signal change generated by the deformation of the strain gauge 41 covering the surface of the flexible film 42 to obtain the measurement data of the intraocular pressure, specifically including the following steps:

[0036] Step 1. Confirm the integrity of the portable non-corneal contact intraocular pressure measuring device, use the fixing belt 2 to fix the portable non-corneal contact intraocular pressure measuring device on the head of the subject, and align the two through holes of the shell 1 with the eyes of the subject respectively to ensure the accuracy of the test results.

[0037] Step 2. After the subject closes his eyes, the portable non-corneal contact intraocular pressure measuring device is started. At this time, the strain gauge 41 produces initial deformation due to the spherical structure of the eyeball and cornea, and the strain gauge 41 outputs an initial deformation signal. This process is the initialization of the control system circuit 5.

[0038] Step 3. The voice coil motor 31 pushes the push rod 32 to move toward the flexible film 42 under the action of the current of the control system circuit 5 and its own magnetic field. Since the current-carrying wire is acted upon by the Ampere force in the magnetic field, when the current passes through the coil 311, the coil 311 and the push rod 32 fixed at its front end begin to move. The direction and amplitude of the movement are controlled by the signal output by the controller of the control system circuit 5. The control system circuit 5 controls the drive mechanism 3 to output a force with a fixed value of f, and the push rod 32 gradually approaches the flexible film 42. When the push rod 32 contacts the flexible film 42, the strain gauge 41 produces a secondary deformation, and the deformation signal output by the strain gauge 41 changes. Under the action of the push rod 32, the deformation signal output by the strain gauge 41 continues to change until the push rod 32 cannot move. The pressure of the deformation produced by the strain gauge 41 is the intraocular pressure measurement value. The pressure at this time is determined by the deformation signal output by the strain gauge 41, that is, the intraocular pressure measurement value of the subject.

[0039] Step 4. The push rod 32 is returned to the initial detection position to complete the measurement, and the intraocular pressure measurement value obtained in step 3 is compared with the data of the normal intraocular pressure range to determine whether the obtained measurement value is within the normal intraocular pressure range. The data of the normal intraocular pressure range is derived from the data measured by volunteers with normal intraocular pressure using the device of the present invention.

[0040] The currently recognized intraocular pressure detection scheme is to measure the intraocular pressure value of the examinee by flattening the cornea, but the test using this device does not require the cornea to be flattened. If several examinees are only tested without data comparison, then only the relationship between their intraocular pressure can be known, but it is impossible to determine whether the intraocular pressure is normal. The detection step for volunteers is that since the Goldmann applanation tonometer is the "gold standard" tonometer used to measure intraocular pressure internationally, several volunteers are selected to be measured with the Goldmann applanation tonometer. The range of normal intraocular pressure is 1.33~2.80kPa (10~21mmHg), thereby distinguishing volunteers with normal intraocular pressure and volunteers with abnormal intraocular pressure; then let the volunteers with normal intraocular pressure use this device for detection, and record the measured data range. Then, when the examinee's intraocular pressure is normal, the intraocular pressure measurement value measured by the examinee using this device should be within the data range of normal intraocular pressure. Therefore, the measurement result of the examinee can be compared with the data of the normal intraocular pressure range to know whether the measurement value is within the normal intraocular pressure range.

[0041] The pressure change over time measured by the strain gauge 41 can be divided into three processes:

[0042] Process 1: The push rod 32 moves without load, and the strain gauge 41 maintains the initial deformation;

[0043] Process 2: The push rod 32 contacts the flexible film 41 and continues to advance. The strain gauge 41 is subjected to the thrust of the push rod 32 and the reaction force of the eyelid and cornea until the signal of the strain gauge 41 stops changing and the push rod 32 stops advancing.

[0044] Process 3: The push rod 32 retreats to the initial position to complete the intraocular pressure measurement.

[0045] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A portable non-corneal contact intraocular pressure measuring device, characterized in that: The invention comprises a housing (1), a control system circuit (5) and two groups of detection mechanism components (4); the housing (1) is a hollow cavity structure; two ends of a fixing belt (2) are respectively connected to two ends of the housing (1); and two through holes are provided on the side of the housing (1) facing the fixing belt (2); the two groups of detection mechanism components (4) are respectively placed at positions inside the housing (1) where the through holes are provided, and the driving mechanism (3) and the control system circuit (5) of the detection mechanism components (4) are placed inside the housing (1).

2. The portable non-corneal contact intraocular pressure measuring device according to claim 1, characterized in that: The detection mechanism component (4) comprises a strain gauge (41) and a flexible film (42); the flexible film (42) covers the through hole of the housing (1); the strain gauge (41) is an annular structure; the strain gauge (41) is attached to a side of the flexible film (42) facing the inside of the housing (1) cavity; the center of the strain gauge (41) coincides with the center of the through hole.

3. The portable non-corneal contact intraocular pressure measuring device according to claim 1, characterized in that: The driving mechanism (3) comprises a voice coil motor (31) and a push rod (32); the voice coil motor (31) comprises a coil (311) and a permanent magnet (312); the coil (311) is sleeved on the permanent magnet (312); the push rod (32) is fixedly connected to the center position of the end of the voice coil motor (31); the end of the push rod (32) is a hemispherical structure; the end of the push rod (32) faces the through hole of the housing (1); after the coil (311) is energized, the current and the permanent magnet (312) are used to drive the push rod (32) to move.

4. The portable non-corneal contact intraocular pressure measuring device according to claim 1, characterized in that: The control system circuit (5) comprises a pressure sensor module, an analog-to-digital conversion circuit and a controller; a first signal output end of the controller in the control system circuit (5) is connected to a signal input end of the drive mechanism (3), a second signal output end is connected to a wireless communication transmitter, and the first signal input end of the controller is connected to a signal output end of a strain gauge (41) via the pressure sensor module and the analog-to-digital conversion circuit.

5. A non-corneal contact intraocular pressure measurement method according to the portable non-corneal contact intraocular pressure measurement device according to any one of claims 1 to 4, characterized in that: Acquiring intraocular pressure measurement data using signal changes generated by deformation of a strain gauge (41) covering the surface of a flexible film (42), specifically comprising the following steps: Step 1. Confirm the integrity of the portable non-corneal contact intraocular pressure measuring device, and use a fixing belt (2) to fix the portable non-corneal contact intraocular pressure measuring device on the head of the subject, with the two through holes of the housing (1) respectively aligned with the two eyes of the subject; Step 2. After the subject closes both eyes, the portable non-corneal contact intraocular pressure measuring device is started. At this time, the strain gauge (41) generates initial deformation due to the spherical structure of the eyeball and cornea, and the strain gauge (41) outputs an initial deformation signal; Step 3. The voice coil motor (31) pushes the push rod (32) to move toward the flexible film (42) under the action of the current of the control system circuit (5) and its own magnetic field. When the push rod (32) contacts the flexible film (42), the strain gauge (41) generates secondary deformation, and the deformation signal output by the strain gauge (41) changes. Under the action of the push rod (32), the deformation signal output by the strain gauge (41) continues to change until the push rod (32) cannot move. At this time, the pressure generated by the deformation of the strain gauge (41) is the intraocular pressure measurement value. The pressure at this time is determined by the deformation signal output by the strain gauge (41), which is the intraocular pressure measurement value of the subject. Step 4. The push rod (32) returns to the initial detection position to complete the measurement, and compares the intraocular pressure measurement value obtained in step 3 with the data of the normal intraocular pressure range to determine whether the obtained measurement value is within the normal intraocular pressure range.

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