Devices, systems and methods for corneal biomechanical diagnosis

Abstract

The content described herein includes systems and methods for devices for drug delivery and ophthalmic diagnostics, intended to assist in diagnosing the physical state of the cornea by projecting droplets onto the eye. In some embodiments, an apparatus includes a liquid sampling unit, an electrically controlled droplet generator, and a steering unit. In some embodiments, a liquid sampling unit is configured to project an amount of liquid, while an electrically controlled droplet generator receives the amount of liquid and outputs one or more charged droplets. The diverting unit uses an electrostatic force to divert the charged droplets along a trajectory onto the cornea of the patient's eye.

Description

Cross Reference to Related Applications

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 579,455, filed August 29, 2023, which is hereby assigned to the assignee of the present application, and which is hereby incorporated by reference in its entirety as if fully set forth below for all applicable purposes. BACKGROUND

[0002] Predictability of corneal response and healing is a key source of error in refractive outcomes, corneal refractive outcomes, and corneal disease outcomes. Refractive surgery planning uses population-based average values for corneal biomechanics. However, about 1% of LASIK patients experience ectasia. Ectasia is a condition characterized by thinning and bulging of the cornea, leading to irregular corneal shape, which in turn causes progressive myopia (nearsightedness) and astigmatism (twisted vision).

[0003] Post-LASIK ectasia is another form of corneal ectasia that can occur after LASIK surgery, a common form of refractive surgery designed to correct vision. In post-LASIK ectasia, the cornea thins and bulges forward after surgery, which can negatively impact vision. Progression of ectasia can cause significant vision impairment. Early stages can be managed with corrective lenses, but severe cases can require treatment such as corneal cross-linking (a treatment that strengthens the cornea), special contact lenses, or even corneal transplantation.

[0004] Surgical-induced astigmatism (SIA) is a vision impairment that can occur as a result of certain types of eye surgery. Astigmatism is a common refractive error of the eye that causes vision to be distorted or blurred. In SIA, the astigmatism is caused by changes in the shape of the cornea resulting from the surgical procedure. SIA can occur after a variety of surgical procedures, including LASIK, PRK, and cataract surgery. The exact cause of SIA will depend on the specific surgical procedure, but is generally related to the way the cornea is manipulated or reshaped during the procedure. SUMMARY

[0005] Embodiments described herein provide a method for diagnosing a corneal biomechanics of a patient’s eye. In some embodiments, the method includes projecting liquid microdroplets formed from an amount of liquid and charging the liquid microdroplets to form charged microdroplets. The charged microdroplets are diverted along a trajectory onto the cornea using a dynamic electric field. In some embodiments, the method includes measuring a response of the charged microdroplets impacting the cornea using an OCT measurement unit. In some embodiments, the measured response is used to determine a physical parameter of the cornea (i.e., corneal biomechanics). The physical parameter of the cornea is used to determine a condition of the cornea. In some embodiments, a diagnosis is output based on the condition of the cornea.

[0006] Some embodiments include a device for projecting a microdroplet onto a cornea of a patient’s eye to measure corneal biomechanics used in ophthalmic diagnostics. Some embodiments include a liquid sampling unit, an electrically controlled microdroplet generator, and a steering unit. In some embodiments, the liquid sampling unit is configured to project an amount of liquid. In some embodiments, the electrically controlled microdroplet generator is configured to receive the amount of liquid and output one or more charged microdroplets. In some embodiments, the steering unit is configured to electrostatically steer the one or more charged microdroplets along a trajectory onto the cornea of the patient’s eye.

[0007] In some embodiments, the liquid sampling unit includes one or more pressurized containers having an outlet and a valve coupled to the outlet via one or more conduits. In some embodiments, actuation of the valve outputs the amount of liquid. In some embodiments, the liquid sampling unit includes one or more vented containers having a first outlet, a valve coupled to the first outlet via one or more conduits, a pump coupled to the valve, and a pressure sensor controller coupled to the pump. In some embodiments, the pressure sensor controller is configured to sense a pressure of the amount of liquid and adjust a flow rate of the pump based on the sensed pressure. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 A schematic diagram of an optical diagnostic system is depicted in accordance with some embodiments.

[0009] Figures 2A-2B A schematic diagram of a liquid jet-droplet device is depicted in accordance with some embodiments.

[0010] Figure 3 A flowchart depicting an optical diagnostic method is depicted in accordance with some embodiments.

[0011] Figure 4 A schematic diagram of an optical diagnostic system is depicted in accordance with some embodiments. DETAILED DESCRIPTION

[0012] The present disclosure will now be described in detail by way of reference only to the figures, which are provided as illustrative examples so as to enable one of ordinary skill in the art to practice the disclosure. It is to be noted that the figures and examples below are not meant to limit the scope of the present disclosure to the specific embodiments described, as other embodiments are possible using a combination of some or all of the described or illustrated elements. Furthermore, where a certain element can be implemented in a given embodiment in a particular way, the disclosure should not be construed to be limited to that particular implementation, as other embodiments are possible using a different implementation of that element. In addition, where certain elements can be implemented in a given embodiment using known components, only those specifically required of such known components for an understanding of the present disclosure will be described in detail so as not to obscure the present disclosure in unnecessary detail.

[0013] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are "coupled" shall mean that the parts are joined or operate together either directly or indirectly, i.e., by way of one or more intervening parts or components, unless indicated otherwise. As used herein, "directly coupled" means that two elements are directly in contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other. As used herein, "operatively coupled" means that two elements are coupled in a manner that one is operable to affect the other. It will be appreciated that two elements A and B are "operatively coupled" where A has an effect on B, and / or B has an effect on A, even though the effect can not be direct. As used herein, "substantially" means any appreciable difference is negligible so that any difference is within the operational tolerance of one of ordinary skill in the art and provides the desired performance and results as described in the embodiments herein. Descriptions of ranges include endpoints.

[0014] As used herein, the word "unitary" means a component is created as a single piece or unit. That is, the component is not created in separate pieces or units that are coupled to one another as in the case of a frame, panel, or the like. As used herein, the statement that two or more parts or components "engage" one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components. As used herein, the term "number" shall mean one or an integer greater than one (i.e., a plurality).

[0015] In the example embodiments described herein, embodiments showing a single component should not be taken as limiting; unless otherwise specified herein, the disclosure is intended to encompass other embodiments involving plural identical components, and vice versa. Furthermore, the applicant is not intending to be bound by any term in the specification or claims other than those that are explicitly set forth, unless the context clearly indicates otherwise. Further, the disclosure encompasses existing and future known equivalents.

[0016] Corneal biomechanics, such as corneal stiffness, can play an important role in understanding, diagnosing, and treating diseases such as glaucoma, keratoconus, and ectasia. Detailed clinical assessment of corneal biomechanics has the potential to revolutionize the ophthalmic industry, for example, by providing personalized LASIK (laser-assisted in-situ keratomileusis) and cataract surgery. One way to measure corneal biomechanics is to capture the response of the cornea to an external force. For example, to measure corneal stiffness, some devices can apply a high-pressure air pulse to induce a large corneal displacement (e.g., greater than 2 mm). However, large corneal displacements typically have a significant nonlinear component, which can hinder the device from accurately measuring corneal stiffness. Additionally, the amplitude of deformation of the cornea is affected by the stability of the air pulse source.

[0017] The ophthalmic diagnostic systems and methods described herein provide a range of advantages for corneal biomechanics diagnostics. Corneal biomechanics diagnostics refer to measuring or quantifying corneal biomechanics properties. Efficiently quantifying corneal biomechanics properties of both healthy and diseased corneas helps to improve predictability and surgeon confidence when providing treatment. For example, as described in detail below, utilizing personalized measurements of corneal biomechanics properties provided according to embodiments described herein improves the ability to predict the risk of corneal surgical interventions such as post-LASIK ectasia and improves the predictability of corneal treatments. Personalized corneal biomechanics measurements can further be used to evaluate the effectiveness of cross-linking treatment interventions and also monitor the progression / delay of collagen degradation. Furthermore, because corneal biomechanics are highly correlated with myopia and affect the success rate of corneal refractive surgery, personalized corneal biomechanics measurements can provide more accurate myopia diagnosis, which is advantageous because high myopia can increase the risk of glaucoma.

[0018] Further, some embodiments herein provide methods and systems for drug delivery during corneal biomechanical diagnostics. Drug delivery herein refers to the administration of liquid droplets containing a pharmaceutical agent for the eye. For example, such pharmaceutical agents can include viscoelastic agents that keep the cornea hydrated and maintain the shape of the cornea during OCT measurements and corneal evaluation. In some embodiments, the liquid pharmaceutical agent can include a saline solution for flushing the cornea and internal system components used during OCT measurements and corneal evaluation to remove any debris or bacteria. In some embodiments, the liquid pharmaceutical agent can include an anesthetic to numb the eye prior to evaluation to minimize any discomfort or pain for the patient.

[0019] As described herein, generating accurate and individualized measurements of corneal biomechanical properties further advantageously addresses the existing unpredictability issues associated with post-operative corneal responses and healing, which are a major source of error in cataract refractive outcomes, corneal refractive outcomes, and keratological outcomes. For example, with the corneal biomechanical diagnostic systems and methods described herein, by generating accurate and individualized measurements of corneal biomechanical properties based on individual corneal biomechanical mapping relationships, and customizing treatment plans for individual patients based on such accurate and individualized measurements, the following effects can be achieved: improving cataract surgery outcomes through patient-specific SIA calculations; optimizing limbal relaxing incision (LRI) outcomes through patient-specific calculations; providing more informed treatment decisions for corneal refractive surgery; and improving Ortho-k outcomes.

[0020] Reference is now made to the following drawings Figure 1 , Figure 1 A corneal biomechanical diagnostic system 100 is depicted. The system 100 includes an OCT unit 102 and a liquid jet-droplet generator 140. The liquid jet-droplet generator 140 projects droplets 160 onto the cornea 192 of a patient’s eye 190. When the projected droplets 160 hit the cornea 192, the impact causes forced oscillations of the corneal tissue via the transfer of kinetic energy from the projected droplets 160 to the tissue of the cornea 192. The forced oscillations (or transfer of kinetic energy) cause viscoelastic and optical responses in the cornea, including the generation of propagating shear waves, which are observed by the OCT unit 102. As discussed in further detail below, the viscoelastic response of the cornea is a measure of the oscillations of the cornea. The optical response includes changes in the shape of the cornea under mechanical stress (e.g., the impact of the projected liquid) and changes in the backscattering properties of the cornea. The OCT unit 102 is designed to observe the viscoelastic and optical responses and generate corresponding data indicative of such responses.

[0021] Backscattering characteristics of the cornea 192 refer to the phenomenon of light incident on corneal tissue being scattered backward (i.e., backscattered) or in its direction of origin. Backscattered light can provide information about the cornea's optical response under mechanical stress, corneal shape, corneal structure, corneal thickness, curvature, and biomechanical properties. Therefore, by analyzing the corneal backscattering characteristics, researchers and clinicians can gather valuable information about corneal shape, structure, and biomechanical properties under various conditions. Backscattering can be observed on images of the cornea 192 provided by the OCT unit 102. Measurements of backscattering on the images can be used to visualize and / or map the corneal layers in the cornea 192 and assess changes in shape and structure under mechanical stress.

[0022] In some embodiments, the OCT unit 102 measures the propagation of mechanical shear waves at the surface of the cornea 192. Wave propagation occurs when a projector (e.g., a projected droplet 160) impacts the eye 190. Due to the impact, kinetic energy is transferred from the liquid droplet to the surface of the cornea. This transfer of kinetic energy causes a shear wave to propagate along the surface of the cornea. As described in further detail below, observing shear wave propagation provides Young's modulus, which can then be used for diagnosis. In addition to determining the corneal condition of the eye, having personalized shear wave propagation data for individual patients advantageously improves the accuracy of preoperative healing prediction and minimizes the need for postoperative correction.

[0023] like Figure 1 As shown, the OCT unit 102 includes an OCT interferometer 104, optical components 107, an eye-tracking unit 120, and a controller 124. The OCT unit 102 operates to generate high-resolution images and / or measurements of the eye 190, which provide detailed information about the cornea and other structures within the eye 190.

[0024] In some embodiments, the OCT interferometer 104 emits a laser beam 150 to generate an interference pattern from reflected light from the eye 190. Corneal biomechanical data are then derived from high-resolution interference pattern images of the eye 190, which provide detailed information about the cornea 192 and other structures within the eye 190.

[0025] In some embodiments, the optical component 107 may include a fast-scanning mirror 106, a slow-scanning mirror 108, a thermal mirror 112, an LED 116, anterior eye optics 114, and / or a controller 124. The fast-scanning mirror 106 and the slow-scanning mirror 108 operate together to scan the laser beam 150 and obtain a three-dimensional image (not shown) of the eye tissue. For example, the fast-scanning mirror 106 may cause the laser beam 150 to scan at high speed in one direction, while the slow-scanning mirror 108 may cause the laser beam 150 to scan in a different direction (e.g., vertical). The combined scanning mirrors described above allow the OCT unit 102 to generate a high-resolution image of the eye 190 in a relatively short time.

[0026] In some embodiments, optical component 107 adjusts and / or modifies the laser beam 150 by adjusting one or more parameters of the laser beam 150, such as spot size, beam intensity, etc. In some embodiments, optical component 107 may include one or more of a beam splitter, a beam expander, and / or a polarization beam splitter. For example, in some embodiments, a beam splitter splits the beam into two or more beams. A beam splitter can be used to split the laser beam 150 into two separate beams, which can then be recombine, for example, by aligning the peaks and valleys of each beam to create a single, stronger beam. A beam expander can be used to increase or decrease the spot size of the laser beam 150.

[0027] In some embodiments, the optical component 107 may include additional beam-directing optics for scanning the laser beam 150 along the cornea 192. Figure 1 (Not shown in the image). For example, in some embodiments, optical component 107 may include mirrors, prisms, and / or focusing lenses, such as collimators and / or objectives. In some embodiments, optical component 107 may include optics with alignment brackets (not shown) for precisely and stably aligning the laser beam 150. The optics with alignment brackets allow controller 124 to precisely adjust the position and angle of each optical component (e.g., 106, 108, 110, 112, and / or 114) to adjust the laser beam 150. In some embodiments, the optics with alignment brackets may be integrated as part of eye-tracking unit 120.

[0028] In some embodiments, anterior eye optics 114 (e.g., one or more eyepieces) focuses the laser beam 150 onto the cornea 192. In some embodiments, a heat reflector 112 may be used to combine visible light with near-infrared OCT light. In some embodiments, an LED 116 may be used for illumination. In some embodiments, anterior eye optics 114 may collimate the laser beam 150 and direct the laser beam 150 toward the eye 190.

[0029] The eye-tracking unit 120 can track the position of the eye 190 and maintain a stable connection between the laser beam 150 and the eye 190. For example, the eye-tracking unit 120 tracks the position of the eye 190 and ensures that the laser beam 150 remains accurately focused on the cornea 192. Accurately focusing the laser beam 150 is advantageous because even a small movement of the eye 190 could cause the laser beam 150 to deviate from its target position on the cornea 192, resulting in inaccurate OCT measurements.

[0030] In some embodiments, the eye-tracking unit 120 uses a combination of a camera (not shown) and an algorithm to monitor the position of the eye. The eye monitoring algorithm and operations may be stored in the processor and memory (not shown) of the eye-tracking unit 120. The camera detects the position of the pupil and the position of any reflections from the cornea 192. The algorithm then uses the positions of the pupil and reflections to calculate the position of the eye and determine the adjustment of the laser beam 150.

[0031] In some embodiments, the eye-tracking unit 120 communicates wirelessly or wiredly with a controller 124, which receives data from the eye-tracking unit 120 and uses real-time eye-tracking data to adjust the position of the laser beam 150. Real-time eye tracking allows the OCT unit 102 to maintain a stable connection between the laser beam 150 and the cornea 192, even when the eye 190 moves during operation of the OCT unit 102. For example, to implement real-time eye tracking, the eye-tracking unit 120 uses a compensation algorithm to correct for any movement of the eye 190 that may occur during the corneal biomechanical evaluation process described herein. The compensation algorithm ensures that the OCT unit 102 produces accurate and reliable measurements, even when the eye 190 moves during measurement. The compensation algorithm may be present on the controller 124 and / or the eye-tracking unit 120. The eye-tracking unit 120 communicates with and can be controlled by the controller 124.

[0032] Controller 124 can control the movement of optical components 107, including the scanning of the fast-scan mirror 106 and the slow-scan mirror 108 described above. Controller 124 adjusts the position of the laser beam 150 based on data received from eye-tracking unit 120. In some embodiments, controlling the movement of optical components 107 and adjusting the position of the laser beam 150 based on data received from eye-tracking unit 120 can be implemented by controller 201, which will be discussed in further detail below (see Figure 2 below). Controller 124 includes a processor and memory (not shown) for storing instructions and executing operations and programs as described in one or more embodiments herein. Figure 1 As shown, the liquid jet-droplet generator 140 communicates with the OCT 102 via the controller 124.

[0033] In some embodiments, system 100 may utilize different protocols for wireless and / or wired communication between OCT unit 102 and liquid jet-droplet generator 140 to ensure reliable and efficient data transmission. One or more wireless communication protocols may be implemented, such as Wi-Fi (IEEE 802.11a / b / g / n / ac / ax), Bluetooth, Bluetooth Low Energy, ZigBee, Z-Wave, and / or other wireless communication protocols, which provide secure, low-power, and high-speed communication to facilitate seamless data exchange and control within system 100. In some embodiments, wired communication protocols may be used due to environmental factors, signal interference, or other constraints. In some embodiments, various components of system 100 may be configured to simultaneously or selectively support both wireless and wired communication protocols, depending on specific requirements.

[0034] In some embodiments, the LED (light-emitting diode) 116 can be used for illumination for pupil tracking purposes, including detecting Purkinje images. Purkinje images are reflections of light occurring within the eye and can provide important information about the eye's optical characteristics, allowing for accurate and reliable measurements. Light from the LED 116 is directed toward the eye and reflected from various structures within the eye, including Purkinje images. The reflected light is then captured by a camera in the eye-tracking unit 120 and used to generate an image of the eye and detect the position of the pupil and the Purkinje image. In some embodiments, the LED 116 can also be tuned, depending on specific requirements, to produce optimized light wavelengths, brightness, and light consistency.

[0035] Now combine Figure 1 For reference Figures 2A-2B , Figures 2A-2B An example of a liquid jet-droplet generator 140 according to some embodiments is depicted. Specifically, Figures 2A-2B Liquid jet-droplet generators 240A and 240B are depicted. Liquid jet-droplet generators 240A and 240B are embodiments of liquid jet-droplet generator 140, wherein similarly marked parts and numbers correspond to similar features having similar functions.

[0036] In some embodiments, the liquid jet-droplet generators 240A and 240B respectively include liquid sampling units 204A and 204B. Liquid sampling unit 204B can generally operate similarly to liquid sampling unit 204A, but with some differences, as described in detail below. For example, liquid sampling unit 204B includes a vented, non-pressurized storage tank with a vent, wherein a pump and valve provide fluid flow to deliver the liquid. In contrast, liquid sampling unit 204A includes a pressurized storage tank, which will be described in further detail below.

[0037] like Figure 2A As shown, in some embodiments, the liquid jet-droplet generator 240A includes a housing 202A, a liquid sampling unit 204A, a piezoelectric actuator 210, an electrostatic unit 212, an electrostatic deflection unit 214, an ultraviolet (UV) light emitter 216, a liquid waste collector 218, and / or a waste container 219. To facilitate the generation of various types of liquid-projected droplets, in some embodiments, the liquid sampling unit 204A includes three pressurized storage tanks 206A, 206B, and 206C. In some embodiments, tanks 206A, 206B, and 206C contain different types of liquids or one or more liquids of the same type, used for various functions related to evaluating the biomechanical properties of the eye, drug delivery, and hygiene purposes. Each of tanks 206A to 206C includes an outlet (e.g., a threaded gasket coupling) connected to a conduit 220 for delivering liquid to the piezoelectric actuator 210 when the valve 222 is actuated. In some embodiments, tanks 206A to 206C maintain the pressure and stability of liquid pharmaceuticals, physiological fluids, and / or flushing liquids, respectively, thereby ensuring that the liquids are delivered in a consistent and accurate manner.

[0038] For example, in some embodiments, canister 206A stores liquid medications that will be delivered to the eye during, before, or after the diagnostic procedure. The volume of individual droplets and / or liquids can be determined based on the dosage of the medication to be administered. For example, in some embodiments, the medication may include a dose of 0.05 ml (SYSTANE® Ultra-Lubricating Eye Drops) per application.

[0039] Canister 206B stores a standard physiological fluid that can be used to subject corneal tissue to forced vibration during corneal biomechanical evaluation. In some embodiments, this physiological fluid or reference solution may include, for example, ALCON® Tears NATURALE® Free [preservative-free artificial tears]. In some embodiments, the reference solution may be administered at the recommended dosage of 0.05 ml per application.

[0040] In some embodiments, tank 206C stores rinsing liquid for sterilizing and / or rinsing the liquid jet-droplet generator 240A between different diagnostic procedures. In some embodiments, the rinsing liquid may include distilled water, which may be administered in doses of 5 ml each time. In some embodiments, one or more tanks may include the same type of liquid. In some embodiments, liquid sampling unit 204A may include more or fewer than three tanks, such as one or four tanks.

[0041] In some embodiments, the liquid output from the liquid sampling unit 204A includes an actuated (i.e., open or close) valve 222. The actuated valve 222 allows liquid to flow via a conduit 220 to the piezoelectric actuator 210. In some embodiments, the conduit 220 may include medical-grade plastic tubing and / or other suitable materials. In some embodiments, the valve 222 may include a one-way valve with feedback protection. Actuation of the valve 222 may be performed by the controller 201.

[0042] In some embodiments, because the liquid sampling unit 204A is pressurized and the liquid is completely contained within the pressurized tanks 206A to 206C, it is not necessary to isolate the storage tanks 206A to 206C from the electrical components (e.g., 210, 212, and 214) of the liquid jet-droplet generator 240A. However, in some embodiments, the electrical components (e.g., 210, 212, 214, and / or 216) may be isolated from the storage tanks 206A to 206C.

[0043] As mentioned above, the piezoelectric actuator 210 forms and outputs liquid droplets. Liquid droplets can be formed in various ways. In some embodiments, the piezoelectric actuator 210 can cause the width of the droplet passage to oscillate between a wider and a narrower width. The droplet passage can be formed from a conduit of a flexible tubing. For example, by applying a dynamic voltage to the piezoelectric actuator 210, the surface of the piezoelectric actuator 210 rapidly expands and contracts, causing the passage conduit width to oscillate. Liquid passing through the narrower passage will form a liquid droplet due to the tensile strength of the liquid.

[0044] In some other embodiments, the piezoelectric actuator 210 can form liquid droplets by rapidly changing the pressure of the liquid. Rapid expansion and contraction of the surface of the piezoelectric actuator can cause an increase in air pressure, thereby separating the liquid into individual droplets. The piezoelectric actuator 210 can be coupled to the electrostatic charging unit 212.

[0045] Electrostatic charge unit 212 is used to charge the surface of liquid droplets. By applying a high voltage to the electrostatic charge unit 212 to induce charge, the unit then emits an electric field in the path of each individual droplet, thereby forming charged droplets. The charge in the droplets allows the liquid droplets to be steered, as will be discussed in further detail below. Furthermore, because the droplets are charged and repel each other, this advantageously reduces the risk of droplets merging into larger droplets (which are more difficult to control).

[0046] In some embodiments, the electrostatic charging unit 212 includes a charged electrode and a grounded electrode. The charged electrode and the grounded electrode can be placed perpendicular to the flow direction in a narrow channel to achieve electrostatic charging of the droplets. When the droplets are forced through or squeezed into the narrow channel, a positive or negative pulse is applied to the charged electrode to induce a charge.

[0047] In some embodiments, the electrostatic steering unit 214 controls the trajectory of charged droplets by generating a dynamic electric field. By changing the strength and / or polarity of the electric field, the charged droplets are subjected to a lateral force that causes them to move in the direction of either repulsive or attractive lateral electric forces. For example, the electrostatic steering unit 214 may apply a voltage to electrodes positioned near an electrostatic plate close to the charged droplets. The voltage applied to the electrodes of the electrostatic steering unit 214 generates an electric field that can be used to steer the charged droplets in a desired direction. The strength and direction of the electric field can be adjusted to provide fine control over the movement of the charged liquid droplets.

[0048] In some embodiments, the piezoelectric actuator 210, electrostatic charge unit 212, and electrostatic deflection unit 214 may include various electronic components (not shown) (e.g., electrodes, power supplies, insulators, amplifiers, and / or feedback and control logic) for controlling the movement of the charged droplets. In some embodiments, the power supply voltage may range from a few volts to several kilovolts, depending on the size of the liquid droplets. One or more amplifiers may be implemented to control the voltage applied to the electrodes. The amplifiers may be used to adjust the strength and direction of the electric field in real time, thereby allowing precise control of the movement of the charged droplets. The feedback and control circuitry may monitor the movement of the charged droplets and adjust the electric field accordingly, and may include one or more sensors, signal processing circuitry, and a digital control system. Depending on specific design requirements, other components such as capacitors, resistors, and inductors may also be implemented in various embodiments; for brevity, a discussion of these components is omitted.

[0049] When steering via the electrostatic steering unit 214, Figure 2A In some embodiments, the ultraviolet (UV) emitter 216 can be used to project one or more beams of UV light to sterilize charged droplets. Irradiating individual droplets with UV light sterilizes them before they are directed onto the patient's eye via the electrostatic deflection unit 214. The use of ultraviolet (UV) light to sterilize the droplets helps prevent the growth of bacteria and other contaminants that could potentially infect the patient's eye 190. Figure 2A In the diagram, the UV light emitter is shown positioned after the electrostatic charge unit 212. However, in some embodiments, the UV light emitter 216 may be positioned at different locations.

[0050] In some embodiments, a liquid waste collector 218 is externally coupled to the housing 202. The liquid waste collector 218 can be used to collect any liquid not used during droplet generation. The liquid waste container 219 can be portable and allows for easy disposal of the collected waste. The liquid waste collector 218 captures stray droplets that deviate from their intended trajectory and do not land on the cornea 192. Capturing stray droplets advantageously allows for the collection and reuse of expensive medications that might otherwise be wasted.

[0051] Now for reference Figure 2B In some embodiments, the liquid sampling unit 204B includes vented canisters 205A, 205B, and 205C, each with an outlet connected via conduit 220 to the inlet of valve 222. Valve 222 includes an outlet connected to the inlet of pump 224. Canisters 205A to 205C are vented to allow liquid to be pumped out and projected onto eye 190 using pump 224 and pressure controller 226. Because canisters 205A to 205C are vented, electrical components (e.g., 210, 212, 214, and / or 216) are isolated from storage canisters 206A to 206C. Therefore, in some embodiments, barrier 207 can provide physical separation for isolating canisters 205A to 205C from electrical components (e.g., 210, 212, 214, and / or 216), as further described below.

[0052] Pump 224 includes an outlet that delivers liquid to piezoelectric actuator 210. Pump 224 and pressure controller 226 regulate the flow rate of each type of liquid contained in tank 205. Pressure (e.g., eyepiece) controller 226 includes a pressure sensor (not shown) that senses the pressure of the liquid flowing from the outlet of pump 224 and adjusts the liquid flow rate in pump 224 based on the sensed pressure of the liquid flowing at the output of pump 224. Pressure controller 226 can communicate with controller 201 and ensures proper delivery of liquid to eye 190 during corneal biomechanical diagnostics, which will be described in further detail below.

[0053] Similar to canister 206A, canister 205A can be used to store liquid medication that will be projected onto eye 190 during, before, or after the diagnostic procedure, as described above. Figure 2AThe liquid agents discussed herein are similar or identical. Similar to canister 206B, canister 205B stores a standard physiological fluid that can be used to induce forced vibration of corneal tissue during biomechanical response observation, which will be discussed in detail below. Further, similar to canister 206C, canister 205C stores a flushing fluid that can be used to clean or flush the liquid jet-droplet generator 240B between different diagnostic procedures. Valve 222 and pump 224 control the flow rate of liquid from each of canisters 205A, 205B, and 205C, thereby ensuring proper delivery of liquid to the eye during the diagnostic process.

[0054] like Figure 2B As shown, the liquid sampling unit 204B can be separated from the housing 202B via barrier 207. The function of barrier 207 is to prevent any contamination or mixing of different liquids within the liquid jet-droplet generator 240B. Conduit 220 extends through barrier 207, thereby connecting each storage tank 205A to 205C to valve 222 and pump 224.

[0055] In some embodiments, housings 202A and 202B may be constructed from various materials, depending on specific requirements and design constraints. The materials of housings 202A and 202B depend on factors such as mechanical protection, electrical insulation, and / or regulatory requirements. In some embodiments, housings 202A and 202B may be made of materials that provide mechanical protection to components of liquid sampling units 204A and 204B (e.g., 204, 210, 212, 214, 216, and 218). For example, robust and durable metal alloys, polymers, or composite materials. In some embodiments, housings 202A and 202B provide electrical insulation and prevent the accumulation of static charge. Accordingly, housings 202A and 202B may comprise plastic or ceramic. In some embodiments, the materials selected for housings 202A and 202B may also need to meet specific regulatory requirements, such as those related to biocompatibility or sterilization. Accordingly, in some embodiments, stainless steel or medical-grade plastics may be implemented.

[0056] Now combine Figure 1 Refer to Figure 2 Figure 3 , Figure 3 A method 300 implemented by system 100 is described. Method 300 involves evaluating corneal biomechanical properties by observing the optical and biomechanical responses of the cornea induced by impact of liquid droplets onto the cornea (e.g., 192) of a patient's eye (e.g., 190). In some embodiments, method 300 begins at step 302: generating one or more liquid droplets from a liquid. The liquid may be stored and dispensed by liquid sampling units 204A, 204B. The formation of the liquid droplets may be performed by piezoelectric actuator 210, as discussed above.

[0057] The method continues to step 304: charging the liquid droplets to form charged droplets. Charging the liquid droplets can be performed by electrostatic unit 212. The method continues to step 306: using a dynamic electric field to direct one or more charged droplets along a trajectory onto the cornea of ​​the patient's eye. Electrostatic directing unit 214 can perform step 306.

[0058] The method continues to step 308: measuring the response to the impact of a charged droplet on the cornea 192 using the OCT unit 102, as described above. Due to the impact of the charged droplet, the cornea 192 will vibrate and generate shear waves. In some embodiments, measuring the response may include measuring the vibrational characteristics of the cornea 192 by the OCT unit 102. Such vibrational characteristics may include vibrational amplitude and vibrational frequency. In some embodiments, measuring the response may include measuring the propagation of mechanical shear waves along the surface of the cornea 192 by means of an average phase-sensitive technique, which will be described in detail below. When a liquid jet—a droplet—impacts the surface of the cornea 192, a propagating shear wave is generated, and the wave propagation velocity / rate is related to corneal biomechanics. A shear wave is a mechanical wave that propagates in a direction perpendicular to the applied force (e.g., the impact of the liquid droplet), causing particles within the medium (e.g., the corneal surface) to move parallel to the wavefront.

[0059] In some embodiments, phase-sensitive techniques may focus on detecting and analyzing the phase shift experienced by a shear wave propagating through the cornea 192. This phase information can provide valuable insights into the properties of the cornea 192 or the interaction between the wave and the cornea 192. For example, in a propagating wave, phase represents the position of a point on the wave at a given time within its oscillation period. Phase can be described in angles (typically in radians or degrees), and it changes as the wave propagates through the cornea 192. Phase-sensitive techniques monitor these phase changes and extract information about the properties of the cornea 192, such as its elasticity, dispersion, or refractive index. Thus, in some embodiments, measuring the propagation of mechanical shear waves using phase-sensitive techniques may include tracking the movement of shear waves generated within the corneal tissue and detecting the phase shift of the kinetic energy wave propagating through the cornea 192, thereby allowing the assessment of the elastic properties of the cornea 192, such as Young's modulus. Shear wave velocity is directly related to the elastic modulus of the tissue, which helps in assessing corneal stiffness.

[0060] The method continues to step 310: using the OCT unit 102 to determine one or more physical parameters of the cornea based on the measured response. The physical parameters of the cornea may include response time, vibration amplitude, natural frequency, wave velocity, etc. At step 312, the condition of the cornea is determined based on one or more physical parameters. The condition of the cornea may correspond to Young's modulus, corneal topology, and / or intraocular pressure (IOP).

[0061] The method continues to step 314: outputting a diagnosis based on the condition of the cornea and clinical test data. For example, clinical test data can correlate various eye conditions with IOP and Young's modulus values, and algorithms are used to characterize the physical parameters of the cornea and convert Young's modulus and IOP. This data can be stored remotely or as part of the storage device of system 100 (e.g., 416). In some embodiments, the diagnosis may include cataract treatment based on surgically induced astigmatism, cataract refractive treatment, cataract diffraction treatment, corneal refractive treatment, risk level of post-LASIK complications, and / or corneal reshaping treatment. For example, based on known amounts of IOP level and Young's modulus, various corneal abnormalities can be determined by correlating IOP and Young's modulus values ​​with clinical test data. The condition can be displayed via the user interface of system 100, as discussed further below, or the condition can be communicated to the user in some other way.

[0062] Now combine Figures 1-3 For reference Figure 4 , Figure 4 A schematic diagram of an example system 400 according to some embodiments is depicted, the system having a controller 401 (e.g., similar to or the same as controller 201) implemented for measuring corneal biomechanical properties of a patient's eye. Figure 4 As shown, in some embodiments, the controller 401 communicates with the liquid jet-droplet generator 440 and the OCT unit 102. For example, the controller 401 may communicate with the liquid jet-droplet generator (LDJG) 440 and / or the OCT unit 102 via a network (e.g., a wired or wireless network) or bus 418. The liquid jet-droplet generator 440 is an example of liquid jet-droplet generators 140, 240A, and 240B. In some embodiments, the controller 401 may communicate with the liquid jet-droplet generator 440 and the OCT unit 102 via wired or wireless communication. For example, in some embodiments, the controller 401 may be part of a separate system, apparatus, or console from the LJDG 440 and the OCT unit 102. In another example, the controller 401, LJDG 440, and OCT unit 102 may be housed within the same system, apparatus, or console. In other examples, controller 401 may be contained in or be part of LJDG 440 (e.g., controller 401 may be the same as controller 124), or it may be contained in or be part of OCT unit 102.

[0063] As shown, the controller 401 includes a memory 412, a processor 414, and a storage device 416, and communicates (e.g., via bus 418) with a user interface 402 and an I / O device interface 407. The memory 412 includes machine-readable instructions for executing one or more embodiments described herein. The processor 414 communicates with the memory 412 and is configured to execute the machine-readable instructions stored in the memory 412. The processor 414 may include a central processing unit (CPU), memory, cache, and / or associated circuitry. In some embodiments, the processor 414 may correspond to a single CPU, multiple CPUs, or a single CPU with multiple processing cores. The processor 414 may be a general-purpose computer processor configured for use in an ophthalmology setting to control the LDJG 440 and / or the OCT unit 102. The memory 412 may include random access memory, read-only memory, hard disk drive, non-volatile memory (such as a disk drive, solid-state drive, or a collection of storage devices distributed across multiple storage systems), and / or other suitable forms of local or remote digital storage devices. The accompanying circuitry is conventionally connected to the processor 414 and includes a cache, clock circuitry, input / output subsystem, power supply, and combinations thereof. The I / O device interface 407 allows various I / O devices (e.g., keyboard, display, mouse, pen input, etc.) to be connected to the system 400.

[0064] Processor 414 can retrieve and execute programming instructions stored in memory 412. Similarly, processor 414 can retrieve and store application data present in memory 412. Software routines (programs) and data can be encoded and stored in memory 412 for issuing instructions to processor 414. When executed by processor 414, the software routines transform processor 414 into a dedicated computer (controller) that controls system 100. The software program (or non-transitory computer-readable instructions) that can be read by processor 414 determines which tasks can be performed by the various components of system 100. Controller 401 can be used to control the various components of system 100 (including, for example, OCT unit 102 and / or LJDG 440) and parameters.

[0065] The memory 412 may include non-transitory computer-readable instructions corresponding to the input parameters 415, the OCT / LJDG controller 417, and the corneal measurement module 419. The input parameters can be used to control the operational settings of the OCT unit 102 (e.g., OCT interferometer 104 settings) and / or the LJDG 440. In some embodiments, the input parameters 415 may include the velocity and volume of the droplets projected by the LJDG 440 and operational parameters of the OCT unit 102 (e.g., laser scanning pattern, scanning speed, spot size, intensity, pulse duration, etc.). The corneal measurement module 419 may store information on the viscoelastic response of the eye and the optical response caused by changes in the corneal backscattering characteristics and shape under mechanical stress. The OCT / LJDG controller 417 may store OCT mechanical shear wave propagation analysis operations performed using average phase-sensitive technology. The corneal measurement module 419 may include a mapping relationship between various eye conditions and IOP and Young's modulus values, and includes algorithms for characterizing the biomechanical parameters, Young's modulus, and IOP of the cornea. The controller 401 may determine a diagnosis or provide medical insights based on the biomechanical properties and IOP of the cornea. The user interface 402 may output diagnostic information to clinicians.

[0066] The detailed descriptions and accompanying drawings are supportive and descriptive of this disclosure, but the scope of this disclosure is defined only by the claims. While some best modes and other embodiments for implementing the claimed disclosure have been described in detail, various alternative designs and embodiments exist to practice the disclosure as defined in the appended claims.

[0067] Furthermore, the features of the embodiments shown in the accompanying drawings or the various embodiments mentioned in this specification are not necessarily to be construed as embodiments independent of each other. Rather, each feature described in one of these examples of embodiments may be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the accompanying drawings. Accordingly, such other embodiments may fall within the scope of the appended claims. Exemplary embodiments

[0068] Example 1: An apparatus for projecting microdroplets onto the cornea of ​​a patient's eye for ophthalmic diagnosis, the apparatus comprising: a liquid sampling unit configured to project a quantity of liquid; an electrically controlled microdroplet generator configured to receive the quantity of liquid and output one or more charged microdroplets; a deflection unit configured to electrostatically deflect the one or more charged microdroplets along a trajectory onto the cornea of ​​the patient's eye; and a controller including a processor communicating with a memory having non-transitory machine-readable instructions, wherein, when executed by the processor, the non-transitory machine-readable instructions cause the apparatus to: measure the response to the impact of the one or more charged microdroplets on the cornea using an optical coherence tomography (OCT) measurement unit; determine one or more physical parameters associated with the cornea based on the measured response; determine the condition of the cornea based on the one or more physical parameters; and output a diagnosis based on the condition of the cornea.

[0069] Example 2: The device as described in Example 11, wherein the non-transitory machine-readable instructions further cause the device to sterilize the one or more liquid droplets or the one or more charged droplets by emitting one or more beams of ultraviolet light in the path of the one or more liquid droplets or the one or more charged droplets before the one or more charged droplets impact the cornea.

Claims

1. An apparatus for projecting a droplet onto a cornea of a patient's eye for ophthalmic diagnosis, the apparatus comprising: a liquid sampling unit configured to project an amount of liquid; an electrically controlled droplet generator configured to receive the amount of liquid and output one or more charged droplets; and a steering unit configured to electrostatically steer the one or more charged droplets along a trajectory onto the cornea of the patient's eye. the liquid sampling unit comprises:

2. The apparatus of claim 1, wherein, one or more pressurized containers having an outlet and configured to store liquid; and a valve coupled to the outlet via one or more conduits, wherein outputting the amount of liquid comprises actuating the valve and outputting the amount of liquid provided by the one or more pressurized containers via the valve. the liquid sampling unit comprises:

3. The apparatus of claim 1, wherein, one or more vented containers having a first outlet and configured to store liquid; a valve coupled to the first outlet via one or more conduits; a pump coupled to the valve and configured to output the amount of liquid; and a pressure sensor controller coupled to the pump, the pressure sensor controller configured to sense a pressure of the amount of liquid and adjust the pump based on the pressure of the amount of liquid. the electrically controlled droplet generator comprises:

4. The apparatus of claim 1, wherein, a piezoelectric actuator configured to oscillate a width of a passageway between a first width and a second width; and a capacitive electrostatic charging unit configured to emit an electric field on the passageway, wherein the amount of liquid forms one or more individual droplets when the passageway oscillates from the first width to the second width, and wherein the one or more individual droplets are charged by the electric field, thereby forming the one or more charged droplets. the electrically controlled droplet generator comprises an ultraviolet light emitter configured to project one or more beams of ultraviolet light on the passageway to sterilize the one or more charged droplets.

5. The apparatus of claim 4, wherein, the steering unit comprises one or more electrodes having one or more electrostatic plates that induce an electric field on a passageway of the charged droplets, wherein the steering unit is configured to vary an intensity and a direction of the electric field to control a trajectory of the one or more charged droplets.

6. The apparatus of claim 1, wherein, 7. The apparatus of claim 1, further comprising: a liquid waste collector coupled to a waste container, wherein the liquid waste collector is configured to capture one or more wayward droplets corresponding to charged droplets that deviate from the trajectory. the waste container is removably coupled to the liquid waste collector.

8. The apparatus of claim 7, wherein, ​ 9. The apparatus of claim 1, further comprising: a controller, wherein the controller is in communication with the liquid sampling unit, the electronically controlled microdroplet generator, the steering unit, and an optical coherence tomography (OCT) measurement unit.

10. The apparatus of claim 9, wherein, The controller is configured to measure a physical state of the cornea using the OCT measurement unit.

11. A method for ophthalmic diagnosis of a physical state of a cornea of a patient’s eye, the method comprising: projecting one or more liquid microdroplets formed from an amount of liquid; charging the one or more liquid microdroplets, thereby forming one or more charged microdroplets; steering the one or more charged microdroplets along a trajectory onto the cornea of the patient’s eye using a dynamic electric field; measuring a response to the one or more charged microdroplets impacting the cornea using an optical coherence tomography (OCT) measurement unit; determining one or more physical parameters associated with the cornea based on measuring the response; determining a condition of the cornea based on the one or more physical parameters; and outputting a diagnosis based on the condition of the cornea.

12. The method of claim 11, prior to the one or more charged microdroplets impacting the cornea, the method further comprising: sterilizing the one or more liquid microdroplets or the one or more charged microdroplets by emitting one or more beams of ultraviolet light across a path of the one or more liquid microdroplets or the one or more charged microdroplets.

13. The method of claim 11, wherein, The one or more physical parameters include a response time, a natural frequency, a wave speed, and / or a wave attenuation.

14. The method of claim 11, wherein, The condition of the patient’s eye corresponds to a Young’s modulus of the cornea, a topography of the cornea, and / or an intraocular pressure of the cornea.

15. The method of claim 11, wherein, The diagnosis includes a cataract treatment based on a surgically induced astigmatism, a cataract refractive treatment, a cataract diffraction treatment, a corneal refractive treatment, a risk level of a post-LASIK complication, and / or a corneal corrective surgery treatment.

16. The method of claim 11, wherein, The OCT measurement unit includes: an OCT interferometer configured to emit a laser beam; one or more optical components configured to condition the laser beam and project the laser beam onto the patient’s cornea; and an eye tracking unit configured to track a position of a pupil and detect a physical change of the cornea based on light reflected from the cornea during an impact of the one or more charged microdroplets, wherein the one or more physical parameters are determined based on the physical change of the cornea.

17. The method of claim 16, wherein, The one or more optical components include a fast scanning mirror, a slow scanning mirror, a thermal mirror, one or more light emitting diodes, and / or an output lens.

18. The method of claim 11, wherein, The amount of liquid is output by a liquid sampling unit, the liquid sampling unit including: one or more pressurized containers having an outlet and configured to store liquid; and a valve coupled to the outlet via one or more conduits, wherein outputting the amount of liquid includes actuating the valve and outputting the amount of liquid via the valve.

19. The method of claim 11, wherein, The amount of liquid is output by a liquid sampling unit, the liquid sampling unit comprising: one or more vented containers having a first outlet and configured to store liquid; a valve coupled to the first outlet via one or more conduits; a pump coupled to the valve and configured to output the amount of liquid; and a pressure sensor controller coupled to the pump, the pressure sensor controller configured to sense a pressure of the amount of liquid and adjust the pump based on the pressure of the amount of liquid.

20. The method of claim 11, wherein, The one or more charged droplets are output by an electrically controlled droplet generator, the electrically controlled droplet generator comprising: a piezoelectric actuator configured to oscillate a width of a passage between a first width and a second width; and a capacitive electrostatic charging unit configured to emit an electric field over the passage, wherein forming the one or more liquid droplets from the amount of liquid comprises oscillating the width of the passage from the first width to the second width with the piezoelectric actuator, and wherein forming the one or more charged droplets comprises charging the one or more liquid droplets with the capacitive electrostatic charging unit.

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