Intervention device for myopia and treatment method thereof
By using iontophoresis, optics, and magnetic fields in a multi-layered intelligent eye pad device, the problem of systematic intervention in scleral remodeling in existing technologies has been solved, achieving non-invasive and safe myopia treatment results that are suitable for home use.
Patent Information
- Application Number
- CN202511585395.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-01-02
AI Technical Summary
Existing myopia intervention technologies are difficult to systematically intervene in scleral remodeling at the biomechanical level, and have problems such as side effects or high invasiveness.
Employing a multi-layered intelligent eye pad device, combining iontophoresis, multispectral photobiological regulation, and static magnetic field, it achieves multi-target intervention of the eye through precise temporal synergy. This includes nutrient penetration driven by the iontophoresis layer, monochromatic light stimulation and micro-magnetic field effects of the optical layer, and the host controlling the coordinated operation of each layer.
It achieves non-invasive and safe myopia intervention, actively guides the eyeball shape towards a healthy spherical shape, inhibits pathological growth, promotes scleral reinforcement and normalizes the eyeball's aspect ratio, and is suitable for home use.
Smart Images

Figure CN121242831A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of visual health intervention, in particular to a myopia intervention device and a treatment method thereof. BACKGROUND
[0002] Myopia, especially pathological myopia, has become a global public health problem, one of the fundamental pathological features of which is excessive elongation of the eye axis.
[0003] At present, the mainstream intervention technical solution is to use, for example, corneal molding lenses, low-concentration atropine, etc. Although these technical means can delay the progression to a certain extent, they mainly passively control visual decline, and also have side effects in use. For example, these technical solutions regard the eyeball as a static organ, and the intervention strategy easily affects the dynamic growth and development characteristics of the eyeball of minors, and the single optical or drug path makes it difficult to achieve systematic intervention in scleral remodeling from the biomechanical level. Invasive techniques such as scleral crosslinking have high invasiveness and insufficient safety. SUMMARY
[0004] In order to solve one of the above-mentioned defects, the present application provides a myopia intervention device and a treatment method thereof, which can improve the myopia intervention treatment effect.
[0005] A myopia intervention device, comprising: a host and a replaceable intelligent eye pad connected with the host;
[0006] The intelligent eye pad is designed as a multi-layer structure, which comprises, from the skin contact to the inside, in order:
[0007] A hydrogel contact layer for attaching to the skin and conducting electricity;
[0008] An iontophoresis layer for generating pulse current to drive nutrients in the blood to penetrate the scleral tissue directionally;
[0009] An optical layer for emitting monochromatic light of different wavelengths to act on the cells of the retina;
[0010] A micro-magnetic field layer for generating a micro-magnetic field with a specific shape and intensity;
[0011] The host is used to control the iontophoresis electrode layer, the optical layer and the micro-magnetic field layer to work cooperatively according to a preset timing sequence, so as to intervene and treat the eye.
[0012] In some embodiments, a flexible electrode is arranged on the iontophoresis layer, and the host controls the electrode to generate bidirectional pulse current according to the set parameters.
[0013] In some embodiments, the optical layer generates red light for stimulating the retina, near-infrared light for acting on the sclera, and green light for neural vascular regulation, respectively.
[0014] In some embodiments, the frequency of the pulse current is 1 kHz, and the average current density is <0.3 mA / cm2.
[0015] The iontophoresis layer integrates LED chips of different wavelengths.
[0016] The LED chips include red LED chips of 630-670 nm, near-infrared LED chips of 800-850 nm, and green LED chips of 520-540 nm.
[0017] In some embodiments, the host includes a mainboard, a display screen connected to the mainboard, and a microprocessor, a memory, and a wireless communication module integrated on the mainboard.
[0018] The mainboard is connected to the smart eye pad through a multifunctional flexible connecting line.
[0019] The wireless communication module is connected to the smart terminal through a wireless communication protocol.
[0020] The mainboard is connected to the smart eye pad through a flexible ribbon cable.
[0021] The microprocessor runs a growth algorithm stored in the memory to dynamically adjust treatment parameters according to the user's age and axial data.
[0022] In some embodiments, the smart eye pad further includes:
[0023] A shielding layer, a structural support layer, and an outer protective layer are arranged outside the micro-magnetic field layer, wherein the shielding layer is used for electromagnetic shielding, the structural support layer is used for giving the eye pad a shape, and the outer protective layer is used for external protection.
[0024] The myopia intervention device of the above embodiments includes a hydrogel contact layer, an iontophoresis layer for generating a pulse current to drive nutrients in the blood to penetrate the sclera tissue, an optical layer for emitting monochromatic light of different wavelengths to act on the cells of the retina, a micro-magnetic field layer for generating a micro-magnetic field with a specific shape and intensity, and a host for controlling the iontophoresis electrode layer, the optical layer, and the micro-magnetic field layer to work cooperatively according to a preset timing sequence to intervene and treat the eye. This technical solution designs an intervention device in which electric, optical, and magnetic fields work cooperatively at multiple targets according to a precise timing sequence, targets multiple pathways such as circulation, energy, nerves, and mechanics, forms a complete intervention closed loop of "inhibition-strengthening-guiding", and realizes the effect of active guidance intervention from multiple target points.
[0025] A treatment method of a myopia intervention device, applied to the myopia intervention device, includes:
[0026] The first stage: the optical layer emits green light and the iontophoresis layer generates a pulse current with set parameters under the control of synchronization;
[0027] The second stage: the optical layer stops emitting green light and starts emitting red light and near-infrared light, and the iontophoresis layer continues to generate a pulse current under control;
[0028] The third stage: the iontophoresis layer stops generating a pulse current, the optical layer stops emitting red light and keeps emitting near-infrared light until the intervention treatment ends.
[0029] In some embodiments, the treatment method of the myopia intervention device further comprises:
[0030] Receiving user data input by a mobile terminal before starting the treatment; wherein the user data includes user age and initial axial length;
[0031] Calculating initial treatment parameters according to the user data; wherein the initial treatment parameters include the working timing and working of the iontophoresis layer and the optical layer;
[0032] Controlling the smart eye pad to treat the user according to the initial treatment parameters.
[0033] In some embodiments, the treatment method of the myopia intervention device further comprises:
[0034] Obtaining timing control parameters and equipment parameters during the treatment, and generating and displaying a switch state diagram in the form of a time axis flowchart according to the timing control parameters and equipment parameters;
[0035] Obtaining user axial transformation data and sending it to a mobile terminal, so that the mobile terminal generates and displays a user axial history curve diagram.
[0036] In some embodiments, the treatment time of the myopia intervention device is 20 minutes; wherein the first stage is from the 0th to the 5th minute, the second stage is from the 5th to the 15th minute, and the third stage is from the 15th to the 20th minute.
[0037] The treatment method of the myopia intervention device of the above embodiment controls the optical layer to stop emitting green light and turn on the emission of red light and near-infrared light in the second stage, and keeps the iontophoresis layer to continuously generate pulse current; in the third stage, control the iontophoresis layer to stop generating pulse current, control the optical layer to stop emitting red light and keep emitting near-infrared light; the technical scheme introduces the "growth algorithm", the intervention strategy is dynamically adjusted according to the development stage of children, uses the "growth dilution" effect, corrects the eye length-width ratio from a long-term perspective, passes through the "mechanical integration period", changes the external soft tissue pressure from a pathogenic factor to a treatment resource, actively guides the eye shape to develop towards a healthy spherical shape, realizes active remodeling, all physical parameters are designed within the physiological safe range, without surgery or drugs, safe and non-invasive, wide applicability, easy to use at home.
[0038] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS
[0039] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.
[0040] Figure 1 It is a structural schematic diagram of an example myopia intervention device;
[0041] Figure 2 It is a product form schematic diagram of an example myopia intervention device;
[0042] Figure 3 It is an explosion diagram of an example intelligent eye pad structure;
[0043] Figure 4 It is a circuit structure schematic diagram of an example host;
[0044] Figure 5 It is a treatment method flowchart of an example myopia intervention device;
[0045] Figure 6 It is an example switch state schematic diagram. DETAILED DESCRIPTION
[0046] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary, only for explaining the present application, and cannot be interpreted as a limitation to the present application.
[0047] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this application’s specification means the presence of the stated feature, integer, step, or operation, but does not preclude the presence or addition of one or more other features, integers, steps, or operations.
[0048] The technical solution of this application integrates iontophoresis, multispectral photobiological regulation, and static magnetic field assistance. Through the synergistic effect of multiple physical fields in a temporal sequence, it guides the normal development of the eyeball and promotes the mechanical remodeling of the axial length. By dynamically coordinating multiple physical factors and using specific temporal control logic, it intervenes in and delays the occurrence and development of myopia in minors in a non-invasive manner, thereby inhibiting pathological growth and suppressing abnormal growth of the axial length from the biochemical signal level. It also strengthens the scleral structure, promotes the synthesis and metabolism of scleral tissue, and enhances its biomechanical strength. Furthermore, it guides a healthy form by using the eyeball's own growth and development dynamics and the pressure of surrounding soft tissues to guide the aspect ratio of the eyeball towards normalization, achieving "relative retraction" or "mechanical remodeling" of the axial length.
[0049] like Figure 1 As shown, Figure 1 This is a schematic diagram of an example myopia intervention device, including: a main unit 10 and a replaceable smart eye pad 20 connected to the main unit 10. The smart eye pad 20 is designed with a multi-layer structure, including, from the point of contact with the skin of the eye inward, a hydrogel contact layer 21, an iontophoresis layer 22, an optical layer 23, and a micromagnetic field layer 24. Among them, the hydrogel contact layer 21 is used to adhere to the skin and conduct electricity; the iontophoresis layer 22 is used to generate pulsed current to drive the directional penetration of nutrients in the blood into the scleral tissue; the optical layer 23 is used to emit monochromatic light of different wavelengths to act on the cells of the retina; the micromagnetic field layer 24 is used to generate a micromagnetic field of specific shape and intensity; the main unit 10 is used to control the iontophoresis electrode layer, the optical layer 23, and the micromagnetic field layer 24 to work together in a preset sequence to intervene and treat the eyes.
[0050] refer to Figure 2 As shown, Figure 2 This is a schematic diagram of an example myopia intervention device. The smart eye pad 20 can be designed as a wearable device, conforming to the shape of an ergonomic eye mask. The main unit 10 can be designed into a specific shape according to needs, such as square or oval. The smart eye pad 20 is connected to the interface of the main unit 10 via a flexible ribbon cable. When using it, the user can first connect the smart eye pad 20 to the main unit 10, and then wear the smart eye pad 20. The main unit 10 can be placed in a pocket or hung on a belt, and can be operated and controlled through the buttons on the main unit 10.
[0051] For the smart eye pad 20, the main functional layers include three layers: an iontophoresis layer 22, an optical layer 23, and a micromagnetic field layer 24; preferably, such as Figure 3 As shown, Figure 3 This is an exploded view of an example smart eye pad 20 structure, which can be designed as a seven-layer composite structure, including, from the point of contact with the skin around the eyes inward: a hydrogel contact layer 21, an iontophoresis layer 22, an optical layer 23 and a micromagnetic field layer 24, a shielding layer 25, a structural support layer 26 and an outer protective layer 27.
[0052] In some embodiments, the hydrogel contact layer 21 is made of a skin-friendly material, and the material of the hydrogel contact layer 21 is soft, translucent medical silicone or hydrogel, conforming to the contour of the eye socket. The iontophoresis layer 22 has built-in circuitry and a flexible film, and is equipped with flexible electrodes. It is connected to the host 10 through two electrode contacts, and the host 10 controls the electrodes to generate bidirectional pulse current according to set parameters. The optical layer 23 generates red light for stimulating the retina, near-infrared light for acting on the sclera, and green light for neurovascular modulation.
[0053] For example, the frequency of the pulse current can be 1 kHz, and the average current density can be <0.3 mA / cm². The optical layer 23 has a built-in LED array, integrating at least three sets of LED chips of different wavelengths, namely, micro LED chips of three colors: green, red, and infrared. Specifically, it can include: a 630-670 nm red LED chip, an 800-850 nm near-infrared LED chip, and a 520-540 nm green LED chip. The micro-magnetic field layer 24 has a neodymium iron boron magnetic sheet array, the shielding layer 25 is designed as a metal mesh for priority electromagnetic shielding, the structural support layer 26 can be made of flexible plastic to give the eye pad shape, and the outer protective layer 27 can be a smooth protective film for external protection of the device.
[0054] As in the above embodiments, the three physical fields of electricity, light, and magnetism work together in a precise time sequence to target multiple pathways such as circulation, energy, nerves, and mechanics, forming a complete intervention loop of "inhibition-strengthening-guidance".
[0055] In some embodiments, such as Figure 4 As shown, Figure 4This is a schematic diagram of the circuit structure of an example host, mainly including: a motherboard 11, a display screen 12 connected to the motherboard 11, and a microprocessor 13, a memory 14, and a wireless communication module 15 integrated on the motherboard 11. A casing can also be designed according to requirements. The motherboard 11 is connected to the smart eye pad 20 via a multi-functional flexible connecting cable (the cable mainly contains wires and optical fibers). The wireless communication module 15 connects to the smart terminal via a wireless communication protocol. The motherboard 11 is connected to the smart eye pad 20 via a flexible ribbon cable. For the host 10, the microprocessor 13 can run the growth algorithm stored in the memory 14 to dynamically adjust treatment parameters based on the user's age and axial length data. For example, the host 10 can also connect to a cloud server 40 via the wireless communication module 15 to store relevant data.
[0056] As described in the myopia intervention devices of the above embodiments, green light stimulates retinal ganglion cells, optimizing the microenvironment for subsequent nutrient delivery; the ion electroosmotic layer can drive nutrients in the blood to penetrate directionally into the scleral tissue; near-infrared light can provide energy for scleral fibroblasts, strongly promoting collagen synthesis; and red light can stimulate dopamine secretion and inhibit growth signals, thereby promoting the mechanical remodeling of the eyeball.
[0057] The following describes an example of a treatment method using a myopia intervention device.
[0058] The treatment method of the myopia intervention device provided in this application is applied to the main unit of the myopia intervention device in any of the foregoing embodiments; for example, the user can install a brand-new smart eye pad on the main unit, wear it on the eyes and start the main unit, the main unit will run automatically, and the treatment time is about 20 minutes.
[0059] refer to Figure 5 As shown, Figure 5 This is a flowchart illustrating a treatment method using an example myopia intervention device. The treatment method described in this application mainly includes the following steps:
[0060] Phase 1: Synchronously control the optical layer 23 to emit green light and activate the ion electroosmosis layer 22 to generate a pulsed current with set parameters.
[0061] Specifically, the first stage is the permeation preparation period, which lasts for about 0 to 5 minutes. When the treatment time is 20 minutes, the first stage can be from 0 to 5 minutes. After 5 minutes, the second stage will start automatically.
[0062] For example, after the first stage of treatment begins, the green LED of the optical layer 23 and the iontophoresis layer 22 are turned on simultaneously, which can be turned on with a current of 0.2mA / cm² and green light of 10mW / cm². The green light stimulates the retinal ganglion cells, optimizing the microenvironment for subsequent nutrient delivery, and the iontophoresis begins to drive the nutrients in the blood (such as vitamin C and amino acids) to penetrate into the scleral tissue in a targeted manner. In the first stage, the user may feel a slight visual green light and a tiny pulse sensation on the skin.
[0063] Second stage: Control the optical layer 23 to stop emitting green light and turn on to emit red and near-infrared light, while keeping the ion electroosmosis layer 22 continuously generating pulse current.
[0064] Specifically, the second stage is the deep repair period, which lasts about 5 to 15 minutes. When the treatment time is 20 minutes, the first stage can be from the 5th to the 15th minute. After 15 minutes, it will automatically enter the third stage.
[0065] For example, after entering the second stage, the control optical layer 23 turns off the green LED and turns on the red LED and near-infrared LED, which can turn on 15mW / cm² red light and 25mW / cm² near-infrared light. At the same time, iontophoresis continues. Near-infrared light provides energy to scleral fibroblasts and strongly promotes collagen synthesis (strengthening effect); red light stimulates dopamine secretion and inhibits growth signals (inhibitory effect). This stage is the key stage of repair and strengthening.
[0066] The third stage involves controlling the iontophoresis layer 22 to stop generating pulsed currents and controlling the optical layer 23 to stop emitting red light while maintaining the emission of near-infrared light until the intervention treatment ends.
[0067] Specifically, the third stage is the biomechanical integration phase, which lasts approximately 5 minutes. When the treatment duration is 20 minutes, the third stage can be from the 15th to the 20th minute.
[0068] For example, 5 minutes before the end of treatment, the third stage is entered, iontophoresis is turned off, and only near-infrared LED irradiation is maintained. All currents are stopped, and only near-infrared light continues to irradiate, completing the mechanical integration. This stage allows the reinforced sclera to better adapt to and respond to the continuous physiological pressure exerted by the extraocular muscles and other surrounding soft tissues with the support of light energy, promoting the mechanical remodeling of the eyeball.
[0069] After the three stages of treatment are completed, the user's relevant data can be synchronized to the mobile terminal 30 or the cloud server 40; the user updates the axial length measurement data every month, and the host 10 will optimize the next treatment plan accordingly to achieve personalized dynamic intervention.
[0070] As described in the above embodiments, the technical solution involves three stages of intervention treatment, in which the three physical fields of electricity, light, and magnetism work together in precise timing to form an intervention closed loop of inhibition-reinforcement-guidance, actively guiding the shape of the eyeball towards a healthy spherical shape, thus achieving good intervention treatment effects.
[0071] In some embodiments, the myopia intervention device of this application receives user data recorded by a mobile terminal 30 before starting treatment; wherein the user data includes the user's age and initial axial length; initial treatment parameters are calculated based on the user data; wherein the initial treatment parameters include the working sequence and operation of the iontophoresis layer 22 and the optical layer 23; and the smart eye pad 20 is then controlled to treat the user based on the initial treatment parameters.
[0072] Specifically, when a user uses the device for the first time, they can input parameters such as age and initial axial length through the APP on the mobile terminal 30. The growth algorithm built into the host 10 will generate a set of initial treatment parameters, and then intervene and treat the user based on the initial treatment parameters.
[0073] In some embodiments, the myopia intervention device of this application can also acquire timing control parameters and device parameters during the treatment process, and generate a switch state diagram in the form of a timeline flowchart based on the timing control parameters and device parameters for display.
[0074] like Figure 6 As shown, Figure 6 This is an example of a switch status diagram. As shown, the horizontal timeline from left to right represents a 20-minute treatment time. Different background color blocks below the timeline represent three stages. The waveform above the timeline represents the status of each factor. The timeline scale indicates 0 min, 5 min, 15 min, and 20 min. The first stage (0-5 minutes) is the permeation preparation period, the second stage (5-15 minutes) is the deep repair period, and the third stage (15-20 minutes) is the biomechanical integration period. The relevant switch status diagram can be displayed on the display screen 12 of the host 10.
[0075] In some embodiments, the myopia intervention device of this application, during the treatment process, acquires the user's axial length transformation data and sends it to the mobile terminal 30, so that the mobile terminal 30 generates and displays the user's axial length history curve.
[0076] As described in the above embodiments, the technical solution introduces a "growth algorithm," and the intervention strategy is dynamically adjusted according to the child's developmental stage. Utilizing the "growth dilution" effect, it corrects the aspect ratio of the eyeball from a long-term perspective, making it more dynamic and forward-looking. The three physical fields of electricity, light, and magnetism work in precise timing, with multi-target synergy, targeting multiple pathways such as circulation, energy, nerves, and mechanics, forming a complete intervention loop of "inhibition-consolidation-guidance." Through the "mechanical integration period," external soft tissue pressure is transformed from a pathogenic factor into a therapeutic resource, actively guiding the eyeball shape towards a healthy spherical shape, achieving active guidance and reshaping. All physical parameters are designed within the physiological safety range, requiring no surgery or drugs, making it safe, non-invasive, widely applicable, and easy for home use.
[0077] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A myopia intervention device, characterized in that, The application relates to a myopia intervention device, which comprises the following parts: a host and a replaceable smart eye pad connected with the host; the smart eye pad is designed as a multi-layer structure, which comprises the following parts from the skin contacting layer to the inside in sequence: a hydrogel contact layer for attaching the skin and conducting electricity; an iontophoresis layer for generating pulse current to drive the nutrition in the blood to penetrate the sclera tissue; an optical layer for emitting monochromatic light of different wavelengths to act on the cells of the retina; a micro-magnetic field layer for generating a micro-magnetic field with specific form and intensity; the host is used for controlling the iontophoresis electrode layer, the optical layer and the micro-magnetic field layer to work cooperatively according to the preset time sequence, so that the eye is intervened and treated.
2. Myopia intervention device according to claim 1, characterized in that The iontophoresis layer is provided with flexible electrodes, and the host controls the electrodes to generate bidirectional pulse current according to the set parameters.
3. Myopia intervention device according to claim 1, characterized in that The optical layer generates red light for stimulating the retina, near-infrared light for acting on the sclera and green light for nerve and blood vessel regulation, respectively.
4. Myopia intervention device according to claim 2 or 3, characterized in that The frequency of the pulse current is 1 kHz, and the average current density is less than 0.3 mA / cm2; The iontophoresis layer is integrated with LED chips of different wavelengths; The LED chips comprise red light LED chips of 630-670 nm, near-infrared light LED chips of 800-850 nm and green light LED chips of 520-540 nm.
5. Myopia intervention device according to claim 1, characterized in that The host comprises a mainboard, a display screen connected with the mainboard and a microprocessor, a memory and a wireless communication module integrated on the mainboard; The mainboard is connected with the smart eye pad through a multifunctional flexible connecting line; The wireless communication module is connected with a smart terminal through a wireless communication protocol; The mainboard is connected with the smart eye pad through a flexible strip-shaped cable; The microprocessor runs a growth algorithm stored in the memory, and dynamically adjusts the treatment parameters according to the age and eye axis data of the user.
6. Myopia intervention device according to claim 1, characterized in that The smart eye pad further comprises: a shielding layer, a structural support layer and an outer protective layer arranged outside the micro-magnetic field layer, wherein the shielding layer is used for electromagnetic shielding, the structural support layer is used for giving the eye pad a shape, and the outer protective layer is used for external protection.
7. A method of treatment of myopia intervention device, characterized in that, The application is applied to the myopia intervention device in any one of claims 1-6, and comprises the following steps: a first stage: synchronously controlling the optical layer to emit green light and the iontophoresis layer to generate pulse current with set parameters; a second stage: controlling the optical layer to stop emitting green light, controlling the optical layer to emit red light and near-infrared light and keeping the iontophoresis layer to continuously generate pulse current; a third stage: controlling the iontophoresis layer to stop generating pulse current, controlling the optical layer to stop emitting red light and keeping the optical layer to emit near-infrared light until the intervention treatment is completed.
8. The method of treatment of myopia intervention device according to claim 7, characterized in that, The application further comprises the following steps: receiving user data input by a mobile terminal before starting the treatment, wherein the user data comprises the age and initial eye axis length of the user; calculating initial treatment parameters according to the user data, wherein the initial treatment parameters comprise the working time sequence and working of the iontophoresis layer and the optical layer; controlling the smart eye pad to treat the user according to the initial treatment parameters.
9. The method of treatment of myopia intervention device according to claim 7, characterized in that, The application further comprises the following steps: obtaining time sequence control parameters and equipment parameters in the treatment process, and generating and displaying a switch state diagram in the form of a time axis flowchart according to the time sequence control parameters and the equipment parameters. The eye axis conversion data of the user is acquired and sent to the mobile terminal, so that the mobile terminal generates and displays an eye axis history curve of the user.
10. The method of treatment of myopia intervention device according to claim 7, characterized in that, The treatment time of the myopia intervention device is 20 minutes; wherein the first stage is the 0th to 5th minute, the second stage is the 5th to 15th minute, and the third stage is the 15th to 20th minute.