Tonometer with sensor array for measuring corneal profile

Abstract

Obtaining corneal measurements for non-contact tonometry. Systems, devices, and methods for determining intraocular pressure (IOP) of an eye are provided. The system may include a pump configured to generate an air puff and a nozzle configured to direct the air puff along a first axis toward the eye. The system may further include a light source distal to the nozzle and oriented to emit a light beam along a second axis transverse to the first axis toward a first linear optical sensor. A first portion of the light beam illuminates an outer surface of the eye, and a second portion of the light beam passes through a front surface of the eye. The system may further include a first linear optical sensor positioned distal to the nozzle and configured to receive the second portion of the light beam.

Description

[Technical Field]

[0001] The present disclosure relates generally to devices and methods for measuring intraocular pressure (IOP) in the human eye, and more particularly to devices that generate air puffs for non-contact tonometry. [Background technology]

[0002] Intraocular pressure (IOP) quantifies the pressure of aqueous humor within the eye. Many individuals suffer from disorders such as glaucoma that cause chronically elevated IOP. Over time, elevated IOP can cause damage to the eye's optic nerve and lead to vision loss. Effective treatment of glaucoma (e.g., using medication) requires adherence to medication schedules and knowledge of the patient's IOP. The more recent or recent the measurement, the more relevant it is, and therefore the more effective the resulting treatment may be. IOP for a given patient can vary significantly based on time of day, exercise, recency of medication use, and other factors. This means that any given measurement is subject to uncertainty; therefore, multiple measurements over an extended period of time may be provided to provide confidence regarding the patient's health status. IOP measurements performed in a doctor's office are typically performed only once or twice a year. These infrequent measurements are less likely to account for fluctuations in a patient's IOP. Additionally, annual or semi-annual measurements in a doctor's office may become outdated or stale due to the time lag from the previous measurement. Frequent home testing may allow for better treatment at lower costs.

[0003] IOP can be measured by tonometry. However, some currently available tonometry devices and techniques have many drawbacks. Contact tonometry is performed in a medical setting and carries both risks of infection and trauma. This procedure also requires numbing the patient's eye, which can be both inconvenient and uncomfortable. Non-contact tonometry involves directing a puff or jet of air at the patient's eye and measuring the resulting ocular deflection. The deflection measurement may be performed by optics or a sensor. In some embodiments, some devices may require precise positioning of the cornea in multiple axes to obtain an accurate corneal deflection measurement. Misalignment in one or more axes may result in an inaccurate or unreliable measurement. For this reason, non-contact tonometry is often performed under the supervision or control of an optometrist or ophthalmologist, rather than in the patient's home. Summary of the Invention

[0004] The present disclosure advantageously describes embodiments of non-contact tonometer devices that include a light source and an optical sensor or sensor array that may allow for some misalignment of the eye in one or more axes. The tonometers described herein include a light source configured to emit a light beam that intersects the axis of the air flow of the tonometer device. The beam has a width or profile in the air jet axis. The optical sensor array includes multiple sensor elements positioned along a straight or curved line and positioned in the optical path of the light source. At least a portion of the light from the light source may be obscured by the profile of the user's cornea such that at least some of the sensor elements are prevented from receiving light from the beam. Thus, the number of sensor elements that detect or record light from the light source may indicate or represent the corneal profile. Multiple measurements may be taken during delivery of the air jet to determine changes in the shape of the cornea (e.g., flattening) over time. Based on these measurements and the pressure of the air jet, IOP may be determined. In some aspects, the embodiments described herein may allow for more flexibility and misalignment in one or more axes. For example, the tonometry devices described herein may allow IOP measurements to be taken while the eye is positioned within a suitable range of positions on the air jet axis, which may make the tonometry devices more suitable for home use by patients themselves.

[0005] According to one aspect of the present disclosure, a system for determining intraocular pressure (IOP) of an eye is provided. The system may include a pump configured to generate an air puff. The system may further include a nozzle in communication with the pump and configured to direct the air puff toward the eye along a first axis. The system may further include a light source disposed distal to the nozzle and oriented to emit a light beam along a second axis transverse to the first axis toward a first linear optical sensor, the light beam having a width along the first axis such that a first portion of the light beam illuminates an outer surface of the eye and a second portion of the light beam passes through a front surface of the eye. The system may further include a first linear optical sensor disposed distal to the nozzle and configured to receive the second portion of the light beam.

[0006] In some embodiments, the first linear optical sensor comprises a linear array of sensor elements arranged along a third axis. In some embodiments, the light source comprises an optical element and a collimating lens configured to collimate the light beam along at least one axis. In some embodiments, the system comprises a collimating lens coupled to the linear optical sensor, the collimating lens configured to linearly focus the light beam toward the linear optical sensor. In some embodiments, the collimating lens is positioned adjacent to the linear optical sensor. In some embodiments, the system comprises a second linear optical sensor positioned adjacent to the first linear optical sensor, the first and second linear optical sensors being oriented toward the light source in a fourth axis. In some embodiments, the fourth axis may be parallel to the second axis.

[0007] In some embodiments, the system comprises a processor configured to receive from a first linear optical sensor a first plurality of displacement measurements obtained over a first period of time and determine intraocular pressure of the eye based on the first plurality of displacement measurements and the first period of time. In some embodiments, the processor is further configured to receive from the first linear optical sensor a second plurality of displacement measurements obtained over a second period of time preceding the first period of time, detect a blink based on the second plurality of displacement measurements and the second period of time, and cause the linear optical sensor to obtain the first plurality of displacement measurements based on the detection of the blink.

[0008] In some embodiments, the system includes a drug delivery module positioned and oriented to release a flow of drug into the eye, and the processor is further configured to cause the drug delivery module to release the flow of drug into the eye, receive a third plurality of displacement measurements from the linear optical sensor obtained over a third period of time, and determine whether the flow of drug has reached the eye based on the third plurality of displacement measurements.

[0009] In some embodiments, the system includes a third optical sensor oriented toward the first axis, and the processor is configured to determine whether the eye is located within a measurement range of the nozzle based on the proximity measurements from the third optical sensor. In some embodiments, the first linear optical sensor includes a one-dimensional array of photodiodes. In some embodiments, the first linear optical sensor includes a two-dimensional array of photodiodes. In some embodiments, the light source is configured to emit light having a center wavelength within the visible spectrum.

[0010] Another embodiment of the present disclosure provides a method for measuring intraocular pressure (IOP) of a patient's eye. The method may include generating an air puff directed along a first axis toward a cornea of ​​the patient's eye, the air puff having a pressure. The method may further include emitting, by a light source, a light beam toward a first photosensor array along a second axis transverse to the first axis, the light beam including a width along the first axis such that a first portion of the light beam illuminates an outer surface of the eye and a second portion of the light beam passes through a front surface of the eye. The method may further include detecting, by the first photosensor array, a width of the second portion of the light beam. The method may further include determining the IOP of the patient's eye based on the detected width of the second portion of the light beam and the pressure of the air puff.

[0011] In some embodiments, detecting the width of the second portion of the light beam includes receiving a first plurality of displacement measurements over a period of time from the first photosensor array. In some aspects, determining IOP is based on the first plurality of displacement measurements. In some embodiments, determining IOP includes determining corneal flattening. In some embodiments, determining IOP is based on timing of corneal flattening. In some embodiments, determining timing of corneal flattening includes determining a maximum displacement based on the first plurality of displacement measurements.

[0012] In some embodiments, the method further includes receiving a second plurality of displacement measurements from the first optical sensor array obtained over the first period of time, detecting a blink based on the second plurality of displacement measurements, and causing the first optical sensor array to obtain the first plurality of displacement measurements at a second time after the first period of time based on the detection of the blink. In some embodiments, the method further includes detecting a pressure of the puff of air with a pressure sensor.

[0013] This Summary is provided to introduce selected concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. A more extensive presentation of the features, details, utilities, and advantages of the disclosed intraocular pressure measurement devices and methods is provided in the following written description of various embodiments of the disclosure and illustrated in the accompanying drawings. [Brief explanation of the drawings]

[0014] Exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. [Figure 1] FIG. 1 is a perspective view of a non-contact tonometer in accordance with at least one embodiment of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 3] FIG. 1 is a top view of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 4] FIG. 1 is a front view of a non-contact tonometer having a nozzle, a proximity sensor, and a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 8]FIG. 1 is a front elevation view of a non-contact tonometer having a nozzle, a proximity sensor, and a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. [Figure 9] 1 is a graph illustrating displacement versus time of a cornea deflecting in response to an air jet from a non-contact tonometry device, in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] For purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe them. Nevertheless, it will be understood that no limitations on the scope of the present disclosure are intended. Any alterations and further modifications to the described devices, systems, and methods, and any further applications of the principles of the present disclosure, as would normally occur to one of ordinary skill in the art to which the present disclosure pertains, are fully contemplated and included within the present disclosure. For example, while the devices of the present disclosure are described with reference to handheld devices configured to direct air toward a human eye, it will be understood that the present disclosure is not intended to be limited to this application. The devices and systems are equally well suited for any application requiring the pumping of short puffs, pulses, or jets of air having particular profiles of pressure, density, and flow rate. In particular, it is fully contemplated that features, components, and / or steps described with respect to one embodiment may be combined with features, components, and / or steps described with respect to other embodiments of the present disclosure. However, for the sake of brevity, multiple iterations of these combinations will not be described separately.

[0016] Currently, glaucoma treatment primarily consists of the regular administration of injections or eye drops to lower intraocular pressure (IOP). However, the effectiveness of medications can vary significantly from patient to patient. Furthermore, IOP for a given patient can vary significantly based on time of day, activity, medication use, and other factors. This means that any given measurement is subject to considerable uncertainty; therefore, multiple measurements can be taken over time to provide confidence regarding the patient's health status and appropriate dosing of medications. Effective glaucoma treatment requires adherence to medication schedules and accurate knowledge of the patient's IOP. The more recent the measurement, the more reflective it is of the patient's current condition, and therefore the more effective the treatment. IOP measurements taken in the clinic once or twice a year cannot account for fluctuations in a patient's IOP, and measurements can become outdated due to the time lag from the most recent measurement.

[0017] IOP may be measured through non-contact tonometry, which involves directing an air puff at a patient's eye and measuring the resulting deflection. The air pressure required to temporarily flatten an area of ​​the patient's cornea equals the patient's IOP. Corneal measurements are obtained by an optical sensor configured to receive light reflected from the cornea. The light source and optical sensor may be oriented at an oblique angle relative to the central axis of the eye, such that the axes of the light source and the optical sensor intersect at a point or location on or near the surface of the cornea. In some embodiments, this arrangement of the light source and the optical sensor receiving the reflected light from the cornea may be somewhat inflexible in that accurate measurements depend on precise positioning of the cornea in all three axes. For example, if the patient's cornea is not precisely positioned at or near the intersection of the light source axis and the optical sensor axis, accurate IOP measurements are unlikely.

[0018] The present disclosure describes devices, systems, and methods for obtaining corneal measurements for non-contact ocular pressure measurement. An embodiment of the present disclosure includes a non-contact tonometer having an air puff generator, a light source, and an optical sensor array. In some aspects, the light source and the optical sensor array may be positioned relative to one another such that the sensor is configured to receive at least a portion of a light beam directly from the light source. In other words, the optical sensor array may be positioned relative to the light source such that the optical sensor array is in the direct optical path of the light source. In an exemplary embodiment, the light source and the optical sensor array are positioned and oriented laterally with respect to the optical axis of the eye. Thus, the light source projects a light beam onto at least a portion of the side of the eye, with the width of the light beam spanning at least a portion of the depth of the cornea and extending beyond the cornea. The cornea may prevent or inhibit at least a portion of the light beam from reaching the sensor array, while a portion of the light beam passes through the anterior surface of the cornea to reach the optical sensor array. The sensor array may obtain several measurements within a period corresponding to the air puff. For example, the linear sensor may be configured to take 10, 50, 100, 200, 500, 1000, 2000, 5000, and / or any other suitable number of measurements per second. Based on the measurements, the processor may be configured to determine a deflection of the cornea in response to the air puff. Based on the deflection, the processor may be configured to determine or infer the IOP of the eye.

[0019] Embodiments of the present disclosure may include optical components for generating a parallel light beam, a diverging light beam, a fan-shaped light beam, and / or a beam of any other suitable shape. The beam may have a width of several millimeters (e.g., 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 50 mm, etc.), the width being along the z-axis, i.e., the optical axis of the eye. The width of the beam may allow for more flexible positioning and / or misalignment of the cornea during measurement. For example, the width of the beam may allow the cornea to be positioned within a range of several millimeters in the z-axis. In some embodiments, the tonometry device may further include one or more focusing optics for focusing light rays that have passed through the cornea in at least one of the y-axis or z-axis. In some aspects, the focusing optics may allow for flexibility in positioning the cornea and one of the x-axis or y-axis. For example, the focusing optics may include a rod lens configured to focus a beam having a beam height to a line or more focused positions in the y-axis corresponding to the sensor array. For example, the focusing optics may be configured to focus the beam into a line parallel to the sensor array. Thus, the eye can be positioned within a range of positions in both the z-axis and the y-axis while still providing accurate IOP measurements. In some embodiments, by using a beam collimated in at least the z-axis, measurements may require less precision relative to positioning in the x-axis. Thus, the various configurations described herein may provide a more robust and user-friendly tonometry system that may be suitable for home use without medical supervision. In another embodiment, the frequency or wavelength of light used for corneal profile measurement may include infrared, visible light, and / or any other suitable frequency. In this regard, because the light beam from the light source can be directed laterally relative to the optical axis of the eye, higher energy (e.g., higher frequency) light can be used with less risk of eye damage.

[0020] FIG. 1 is a perspective view of a tonometer 100. The tonometer 100 includes a housing 102 that encloses and / or supports multiple components. The tonometer 100 further includes a chin rest 104, an adjustment dial 106, and a head rest 108. The chin rest 104 and the head rest 108 provide stop mechanisms for more consistently and repeatedly positioning a user's eye near an eyecup 134. The adjustment dial 106 may be configured to provide adjustments in one or more axes to position the user's eye within a range of acceptable positions near the eyecup 134. In some embodiments, the adjustment dial 106 may be used to switch from a left eye position to a right eye position and vice versa.

[0021] Tonometer 100 further includes a light source 130 and a sensor array 132. Light source 130 is positioned and oriented to project a beam of light across the eye in a direction transverse to the eye's optical axis. Similarly, sensor array 132 is positioned to collect at least a portion of the light from light source 130, the collected light traveling transverse to the eye's optical axis. In some embodiments, sensor array 132 is configured to receive a portion of the light that is not blocked by the user's cornea. When a jet or puff of air is delivered through eyecup 134, the cornea may flatten or compress. Thus, at moments when the cornea is deflected or compressed to allow more light to pass, a greater amount of light from light source 130 may reach sensor array 132. In some embodiments, the sensor array includes multiple sensor elements positioned along the z-axis or optical axis. The z-axis may be described as being parallel to the direction in which the air puff is delivered and / or parallel to the eye's optical axis. Thus, the number of sensors in the array that register at least a threshold amount of light may correspond to a deflection of the cornea. Thus, the deflection or compression of the cornea due to the air puff over the period that the eye is subjected to the air puff may be determined based on readings from the sensor array 132 .

[0022] The light source 130 and the sensor array 132 may be controlled by a processor or controller contained within the housing 102. The light source 130 and the sensor array 132 may be controlled, along with components of the air puff generator (e.g., pumps, valves, etc.), such that the light source 130 and the sensor array 132 are activated only during periods when an air puff impacts the cornea. The light source 130 may be configured to generate a collimated beam having a width of at least 5 mm to 30 mm in the z-axis. In some embodiments, the collimated beam is 10 mm to 20 mm wide in the z-axis. In some embodiments, the collimated beam is cylindrical. In other embodiments, the collimated beam is elliptical, flat, converging, diverging, or any other suitable profile. In some embodiments, the light source 130 is configured to output a pulsed beam. In other embodiments, the light source 130 is configured to output a continuous beam.

[0023] Tonometer 100 may be a benchtop or desktop tonometer device. In some embodiments, tonometer 100 is configured for home use so that a patient can use tonometer 100 without the supervision or assistance of a physician. Tonometer 100 may include one or more user controls for controlling the IOP measurement procedure. Tonometer 100 may also include a user interface device for displaying instructions, providing feedback to the user, or proper positioning of the eye along the air puff axis, displaying the IOP measurement value, and / or any other suitable interface functionality. A tonometer configured for home use may be desirable and advantageous in some aspects. In this regard, accurate, frequent, and more recent IOP measurements may enable a more tailored or personalized treatment regimen. In this regard, if a patient obtains more measurements throughout the day at various times, the patient may obtain more information regarding the patient's IOP fluctuations throughout the day. Thus, physicians and patients may create treatment schedules or regimens that more precisely match the patient's indications. In other embodiments, tonometer 100 may be configured for use by a physician, for example, in an ophthalmologist's or optometrist's office. In other embodiments, tonometer 100 may be a mobile or portable device. For example, tonometer 100 may be configured for handheld operation. For example, tonometer 100 may include a rechargeable battery so that tonometer 100 can be used without being plugged into a power outlet.

[0024] FIG. 2 is a schematic diagram of a tonometer 100. The tonometer 100 shown in FIG. 2 may be similar in some aspects to the tonometer 100 shown in FIG. 1. In this regard, the tonometer 100 shown in FIG. 2 includes a housing 102, a light source 130, and a sensor array 132. The light source 130 is configured to emit a light beam along a first axis 131. The sensor array 132 is configured to receive light along at least a second axis 133. The tonometer 100 further includes a pump 120 and a nozzle 122 configured to generate an air puff or air jet. The air puff travels along an axis 125. The axis 125 may be aligned or substantially aligned with the optical axis of the eye. Furthermore, the axis 125 may be orthogonal, perpendicular, or otherwise transverse to one or both of the first axis 131 and / or the second axis 133.

[0025] Tonometer 100 further includes a drug delivery module 140 configured to deliver or administer a medication to a patient's eye. For example, drug delivery module 140 may be configured to generate a flow or mist of ophthalmic fluid to the eye as part of a treatment regimen. In some aspects, delivery of medication by module 140 may be based on IOP measurements obtained by tonometer 100. Tonometer 100 further includes an optical sensor 136 distinct from sensor array 132. In some embodiments, optical sensor 136 may be configured for proximity measurement. For example, optical sensor 136 may be configured to determine whether the eye is within a suitable range of nozzle 122. In some aspects, optical sensor 136 may be controlled by controller 110 to determine whether a user is present in the tonometer to activate components of tonometer 100. In some aspects, optical sensor 136 may be used for blink detection. In this regard, controller 110 may be configured to detect a blink based on optical measurements from optical sensor 136 and activate pump 120 and / or nozzle 122 after detecting a blink. In some aspects, pump 120 may include a valve, and controller 110 may be configured to activate the valve to release an air puff. In other embodiments, controller 110 may detect a blink using light source 130 and optical sensor array 132. For example, controller 110 may detect a momentary increase in corneal profile based on a signal from the optical sensor array and determine that a blink has occurred.

[0026] In some embodiments, the pressure applied to the cornea by the air puff increases over a short period of time (15 milliseconds in one example) until it is sufficient to cause a temporary flattening or flattening of the cornea, followed by a brief slight indentation. The pressure may then decrease over a period of time (e.g., 15 ms) so that the cornea flattens again before returning to its normal shape. At both moments of flattening, the non-contact tonometer detects the flattening using an optical sensor.

[0027] In one example, the static pressure of the air puff on the center of the cornea reaches approximately 30 mmHg (4.0 kPa or 0.04 atmospheres) above ambient pressure, with an accuracy of approximately ±1 mmHg or less. For example, the accuracy of the air puff pressure generated by pump 120 and nozzle 122 may be ±0.05 mmHg, ±0.1 mmHg, ±0.5 mmHg, or any other suitable accuracy. Assuming the patient's IOP is somewhere between 5 mmHg and 30 mmHg, the air puff may result in two separate flattening events (one during the rise time and one during the fall time). In some embodiments, tonometer 100 may further include one or more pressure sensors in pump 120, nozzle 122, and / or any other suitable location to monitor the pressure of the air puff emitted through nozzle 122. The controller 110 receiving these measurements then has two separate IOP readings that may be reported separately, averaged, or otherwise.

[0028] Tonometer 100 includes a controller 110 and a memory 112 in communication with controller 110. Memory 112 may store instructions executable by memory 112 to perform one or more of the functions described above. In some embodiments, memory 112 may further store IOP measurements, patient-related data, and / or any other suitable type of information. In some embodiments, memory 112 may store therapy-related data for generating therapy alerts or indicators for the patient. For example, memory 112 may store general and / or patient-specific IOP thresholds for determining whether to output an alert to a user or a network or to cause drug delivery module 140 to deliver medication to the patient's eye.

[0029] 3 is a top view of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem in accordance with at least one embodiment of the present disclosure. Tonometer 100 includes a pump 120 and a nozzle 122 coupled to a first housing portion 101. Tonometer 100 further includes a light source 130 coupled to a second housing portion 103 and a sensor array 132 coupled to a third housing portion. First housing portion 101 is coupled to second housing portion 103 by a first connector element 109, and first housing portion 101 is coupled to third housing portion 105 by a second connector element 107. In some embodiments, connector elements 107, 109 are adjustable to adjust the position of light source 130, sensor array 132, and / or focusing element 138. For example, in some embodiments, connector elements 107, 109 may include telescoping features, sliding clamps, rack and pinion mechanisms, hinges, and / or any other suitable adjustment mechanism.

[0030] Pump 120 and nozzle 122 are configured to generate a puff or jet of air along axis 125. The air puff may have a controlled profile, pressure, duration, velocity, and / or any other air pressure characteristics. Light source 130 is configured to generate light beam 50 in a direction transverse to or perpendicular to axis 125. It will be understood that in some embodiments, beam 50 need not be exactly perpendicular to axis 125. For example, beam 50 may be centered along an axis or direction that is between 75 degrees and 105 degrees relative to axis 125. In FIG. 3, beam 50 is shown collimated. For example, in some embodiments, light source 130 may include a laser element. In some embodiments, the laser element may be an infrared (IR) laser element. In other embodiments, the laser element may be a visible light laser element.

[0031] The beam 50 has a width or thickness along at least the first axis 125. Thus, the beam 50 strikes the eye 10 at a depth range that includes the cornea. A first portion of the beam 50 is intercepted by the eye, and a second portion of the beam 50 that is not intercepted by the eye 10 continues toward the focusing element 138. In some embodiments, the focusing element 138 may include a rod lens. In other embodiments, other types of focusing elements may be used, including Fresnel lenses, focusing mirrors, and / or any other suitable types of focusing elements. The focusing element 138 is configured to focus the beam 50 in at least one axis. For example, in FIG. 3 , the focusing element 138 is configured to focus the beam 50 in the y-axis but not in the z-axis. In this regard, the focusing element 138 being positioned proximate to the sensor array 132 may tolerate some misalignment of the eye in the y-axis. For example, because the beam 50 has a width in the y-axis, there may be a range of suitable positions in the y-axis at which the sensor array 132 can obtain accurate measurements of the corneal profile and deflection.

[0032] Sensor array 132 includes multiple sensor elements arranged along the z-axis (parallel to axis 125). In the illustrated embodiment, sensor array 132 is a one-dimensional linear sensor array. Each element of array 132 may have a width along the z-axis and a spacing along the z-axis. The width and spacing of elements in array 132 may be small enough to detect a range of deflections indicative of a range of IOP. For example, each element of array 132 may have a sensor width ranging from 2 μm to 50 μm and an inter-element spacing ranging from 3 μm to 60 μm. Elements may also have a height along the y-axis. In some embodiments, the y-axis height of the elements of array 132 may provide additional flexibility in corneal positioning relative to array 132 and beam 50. Array 132 may include any suitable number of elements, such as 20, 48, 64, 128, 256, 512, 1024, 2048, etc., and / or any other suitable number of elements, more or less. In some embodiments, the elements of array 132 include photodiodes configured to convert received light into a voltage. The elements of array 132 may be coupled to one another by a bus. In some embodiments, array 132 includes a multiplexer that multiplexes the signals from each of the electrical elements and sends the signals to a controller (e.g., controller 110, FIG. 1). In one embodiment, array 132 includes a Hamamatsu S11639-01 (having 2048 pixels with a width of 14 μm and a total sensor width of 28.672 mm).

[0033] In some embodiments, the sensor array 132 may be configured to provide a signal indicative of the voltage and / or current of each element of the array 132. In other embodiments, the sensor array 132 may be configured to provide, for each element, a signal indicative of a binary value representing whether the sensor element received more than a threshold amount of light. Thus, the signal provided by the array 132 may indicate the number of sensor elements illuminated by the light source 130 based on the flattening or deflection of the cornea. Based on the timing of the flattening of the cornea and the known pressure and characteristics of the air puff, the tonometer 100 can determine the IOP. In this regard, because the light beam 50 strikes the cornea from the side, the tonometer 100 may determine the time from when the air puff reaches the cornea to when the lateral measurement of the cornea first reaches a minimum.

[0034] FIG. 4 is a front view of the non-contact tonometer 100 shown in FIG. 3 , in accordance with an embodiment of the present disclosure. The tonometer 100 includes a light source 130 positioned opposite a sensor array 132 and configured to project a light beam toward the sensor array. A focusing element 138 comprises a cylindrical rod lens for focusing the light beam from the light source 130 onto the sensor array 132. The tonometer 100 further includes a housing portion 134 to which the nozzle 122, the drug delivery module 140, and the user alignment feature 124 are coupled. In some embodiments, the housing portion 134 may include an eyecup. However, the eyecup may be positioned so as not to obstruct the passage of the light beam between the light source 130 and the sensor array 132. The drug delivery module 140 may include a dispensing nozzle for generating a stream or mist of drug. The user alignment feature 124 may include a display, a screen, a mirror, and / or any other suitable feature for guiding a user to position the cornea in an acceptable position for performing an IOP measurement. For example, user alignment feature 124 may include a set of crosshairs, circles, or any other suitable type of shapes, where overlap of the shapes indicates that the user's eyes are correctly positioned on at least one of the axes.

[0035] FIG. 5 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem according to another embodiment of the present disclosure. Similar to the tonometer 100 shown in FIG. 3, the tonometer 200 shown in FIG. 5 includes a nozzle 222, a light source 230, and a sensor array 232. The nozzle 222, the light source 230, and the sensor array 232 may be coupled to respective housing portions, similar to the embodiment shown in FIG. 3. Furthermore, the position and / or orientation of the light source 230 and the sensor array 232 may be adjustable by adjustable connection components of the housing, similar to those described above. In the embodiment of FIG. 5, there is no focusing element.

[0036] Nozzle 222 may be configured to generate a puff or jet of air along axis 225. The air puff may have a controlled profile, pressure, duration, velocity, and / or any other air pressure characteristics. Light source 230 is configured to generate light beam 50 in a direction transverse to or perpendicular to axis 225. It will be understood that in some embodiments, beam 50 may not be exactly perpendicular to axis 225. For example, beam 50 may be centered along an axis or direction that is between 75 degrees and 105 degrees relative to axis 225. In FIG. 3, beam 50 is collimated. For example, in some embodiments, light source 230 may include a laser element. In some embodiments, the laser element may be an infrared (IR) laser element. In other embodiments, the laser element may be a visible light laser element.

[0037] Beam 50 has a width or thickness at least in the direction of first axis 225. Thus, beam 50 strikes eye 20 at a range of depths, including the cornea. Portions of beam 50 that are not intercepted by eye 20 continue toward sensor array 232. In some aspects, the lack of a focusing element in the embodiment of FIG. 5 may reduce eye position errors or misalignment over, for example, the embodiment shown in FIG. 3.

[0038] Similar to that described above with respect to FIG. 3 , sensor array 232 includes multiple sensor elements arranged along the z-axis (parallel to axis 225). In the illustrated embodiment, sensor array 232 is a one-dimensional linear sensor array. Each element of array 232 may have a width along the z-axis and a spacing along the z-axis. The width and spacing of elements in array 232 may be small enough to detect a range of deflections indicative of a range of IOP. For example, each element of array 232 may have a sensor width ranging from 2 μm to 50 μm and an inter-element spacing ranging from 3 μm to 60 μm. Array 232 may include any suitable number of elements, such as 20, 48, 64, 228, 256, 512, 1024, 2048, and / or any other suitable number of elements, more or less. In some embodiments, sensor array 232 may include multiple rows of sensor elements stacked along the y-axis. For example, sensor array 232 may comprise a two-dimensional array. Tonometer 200 may include a controller configured to detect the position of the cornea in the y-axis based on signals from the two-dimensional array. Based on the determined position in the y-axis, the controller may further determine the amount of corneal deflection and / or the timing of the deflection.

[0039] FIG. 6 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem according to another embodiment of the present disclosure. Similar to the tonometer 100 shown in FIG. 3, the tonometer 300 shown in FIG. 6 includes a nozzle 322, a light source 330, a sensor array 332, and a focusing element 338. The nozzle 322, the light source 330, the sensor array 332, and the focusing element 338 may be coupled to respective housing portions, similar to the embodiment shown in FIG. 3. Furthermore, the position and / or orientation of the light source 330 and the sensor array 332 may be adjustable by adjustable connecting components of the housing, similar to those described above. In the embodiment of FIG. 6, the focusing element 338 is positioned proximate the light source 330 instead of proximate the sensor array 332.

[0040] Nozzle 322 may be configured to generate a puff or jet of air along axis 325. The air puff may have a controlled profile, pressure, duration, velocity, and / or any other air pressure characteristics. Light source 330 is configured to generate light beam 50 in a direction transverse to or perpendicular to axis 325. It will be understood that in some embodiments, beam 50 may not be exactly perpendicular to axis 325. For example, beam 50 may be centered along an axis or direction that is 75 degrees to 105 degrees relative to axis 325. In FIG. 6 , beam 50 is first collimated and then focused into a thin line by focusing element 338. Focusing element 338 is positioned proximate light source 330. In some embodiments, focusing element 338 may comprise a rod lens. In other embodiments, focusing element 338 may comprise a semi-cylindrical lens.

[0041] The focused beam 50 has a width or thickness in the direction of the first axis 325. Thus, the beam 50 strikes the eye 10 at a range of depths, including the cornea. The portion of the beam 50 that is not blocked by the eye 10 continues toward the sensor array 332. In some embodiments, the beam 50 may have a focal point at or near the sensor array 332. Thus, the beam 50 may converge between the focusing element 338 and the sensor array 332.

[0042] Similar to that described above with respect to FIG. 3 , sensor array 332 includes multiple sensor elements arranged along the z-axis (parallel to axis 325). In the illustrated embodiment, sensor array 332 is a one-dimensional linear sensor array. Each element of array 332 may have a width along the z-axis and a spacing along the z-axis. The width and spacing of elements in array 332 may be small enough to detect a range of deflections indicative of a range of IOP. For example, each element of array 332 may have a sensor width ranging from 2 μm to 50 μm and an inter-element spacing ranging from 3 μm to 60 μm. Array 332 may include any suitable number of elements, such as 20, 48, 64, 328, 256, 512, 1024, 2048, etc., and / or any other suitable number of elements, more or less.

[0043] Figure 7 is a schematic diagram of a non-contact tonometer having a transverse array-based optical corneal profile measurement subsystem according to another embodiment of the present disclosure. Similar to the tonometer 100 shown in Figure 6, the tonometer 400 shown in Figure 7 includes a nozzle 422, a light source 430, a sensor array 432, and a focusing element 438. The nozzle 422, light source 430, sensor array 432, and focusing element 438 may be coupled to respective housing portions, similar to the embodiment shown in Figure 3. Furthermore, the position and / or orientation of the light source 430 and sensor array 432 may be adjustable by adjustable connecting components of the housing, similar to those described above.

[0044] In the embodiment of FIG. 7 , the beam 50 generated by the light source 430 is a diverging beam. In some aspects, the light source 430 is configured to emit light as a diverging beam. In other embodiments, the light source 430 includes one or more optical components (e.g., lenses, mirrors) configured to generate the diverging beam 50 based on the light emitted by the light source 430. The tonometer 400 includes a focusing element 438 proximate the light source 430. The focusing element 438 is configured to focus the diverging beam 50 in the y-axis to generate a fan beam that diverges in the z-axis and converges in the y-axis. Thus, the focused beam 50 includes a width or thickness along the first axis 425 that increases as the beam 50 approaches the sensor array 432. The beam 50 impinges on the eye 10 at a range of depths, including the cornea. In some aspects, the diverging nature of the beam 50 may magnify variations in the amount of light reaching the sensor array 432 due to the cornea being compressed by the air puff. For example, if the cornea compresses 4 mm, the width 442 of the portion of the beam 50 received at the sensor array 432 may change by, for example, 4.5 mm. In another embodiment, if the cornea compresses 4 mm, the width 442 of the portion of the beam 50 reaching the sensor array 432 may change by 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, and / or any other suitable amount. In some aspects, a more significant change in width 442 based on a diverging beam may improve the resolution of the corneal deflection measurement. For example, a more significant change in width 442 may increase the number of sensor elements that receive rays of the beam 50 due to corneal compression or deflection.

[0045] FIG. 8 is a front view of a non-contact tonometer 500 according to an embodiment of the present disclosure. The tonometer 500 includes a light source 530 positioned opposite a sensor array 532 and configured to project a light beam toward the sensor array. The tonometer 500 includes a focusing element 538 for focusing the light beam from the light source 530 onto the sensor array 532. The tonometer 500 further includes a housing portion 534 to which a nozzle 522 and a user alignment feature 524 are coupled. The user alignment feature 524 may include a display, a screen, a mirror, and / or any other suitable feature for guiding a user to position the cornea in an acceptable position for performing an IOP measurement. For example, the user alignment feature 524 may include a set of crosshairs, a circle, or any other suitable type of shape, where overlap of the shapes indicates that the user's eye is correctly positioned on at least one of the axes.

[0046] The focusing element 538 comprises a semi-cylindrical lens configured to focus light from the light source 530 onto one or both of the first sensor array 532a and / or the second sensor array 532b. The sensor arrays 532a, 532b may be identical or may be arranged in a stacked relationship in the y-axis. In other embodiments, the sensor arrays 532a, 532b may be different sensor arrays. In other embodiments, more than two sensor arrays 532 may be used. For example, the tonometer 500 may include several rows of sensor elements. In some embodiments, a two-dimensional sensor array may be used. Such an arrangement may allow for increased flexibility in the y-axis, as there are multiple rows of sensor elements at different positions on the y-axis to receive light from the light source 530.

[0047] FIG. 9 is a graph of corneal displacement over time. The corneal displacement is due to corneal compression in response to an air puff from the tonometer nozzle. Thus, the greater the amount of compression, the greater the amount of corneal displacement, as shown in graph 600. The displacement reaches a plateau at the point of corneal flattening. At this point, the cornea may become slightly concave. However, because the incident beam approaches the eye laterally, the measured displacement may not detect the instantaneous depression of the cornea. Displacement may be measured by a sensor array, such as a linear sensor array. For example, the sensor array may include multiple sensor elements corresponding to different depths in the direction of displacement. The size and spacing of the sensor elements may be small enough to detect changes in IOP with an accuracy of ±0.05 mmHg, ±0.1 mmHg, ±0.2 mmHg, ±0.5 mmHg, ±1 mmHg, and / or any other suitable accuracy.

[0048] In some embodiments, a processor (e.g., controller 110, FIG. 1) is configured to calculate IOP based on corneal displacement measurements obtained by a sensor array (e.g., 132, 232, 323, 432, 532a, 532b). In this regard, because displacement may be related to the number of sensor elements of the sensor array that are illuminated by the light beam, the processor may determine IOP based on the number of sensor elements that are illuminated by the light beam. In some embodiments, the IOP may be based on known parameters of the air puff, such as pressure.

[0049] The controller may use any combination of hardware, software, and firmware to perform its functions. The controller may employ a fixed instruction set provided in read-only memory (ROM) or may have an updatable instruction set provided in programmable read-only memory (PROM), electrically erasable programmable read-only memory, flash memory, or any equivalent thereof. Readings obtained from the pressure sensor may be stored on the device or communicated externally, as may a running record of the number of times the pump has been started, the number of times the valve has been triggered, and / or the total number of times the device has been used. The pressure value required to trigger the valve may be adjustable or programmable, as may the speed of the compression pump.

[0050] Communication to and from device 100 (including, but not limited to, software updates, firmware updates, or reads from the device) can be achieved using any suitable wireless or wired communication technology, such as a cable interface such as a USB, micro-USB, Lightning, or FireWire interface, Bluetooth, Wi-Fi, ZigBee, Li-Fi, or a cellular data connection such as 2G / GSM, 3G / UMTS, 4G / LTE / WiMax, or 5G. For example, a Bluetooth Low Energy (BLE) radio can be used to establish connectivity with a cloud service for transmitting data and receiving software patches. The controller may be configured to communicate with a remote server or a local device such as a laptop, tablet, or handheld device, or may include a display capable of showing state variables and other information. As described herein, the disclosed pump device can be included in a non-contact tonometer, such as a handheld non-contact tonometer. IOP measurements may be taken using the non-contact tonometer and communicated from the tonometer using the described wireless or wired communication capabilities.

[0051] The logical operations making up the embodiments of the technology described herein may be referred to variously as operations, structures, objects, elements, components, or modules, and it should be understood that they may be performed or arranged in any order unless expressly claimed otherwise or a particular order is inherently required by claim language.

[0052] All directional references, such as upper, lower, medial, lateral, upward, downward, left, right, lateral, front, back, top, bottom, superior, inferior, vertical, horizontal, clockwise, counterclockwise, proximal, and distal, are used for identification purposes only to aid the reader's understanding of the claimed subject matter and do not pose any limitations with respect to the location, orientation, or use of the jet pump, particularly for non-contact intraocular pressure measurement. References to connections, such as attached, coupled, connected, and joined, should be interpreted broadly and, unless otherwise indicated, may include intermediate members between and relative movement between elements of a set of elements. Thus, a reference to connections does not necessarily imply that two elements are directly connected and in a fixed relationship to one another. The term "or" should be interpreted to mean "and / or" rather than "exclusive or." Unless otherwise stated in the claims, listed values ​​should be interpreted as exemplary only and not limiting.

[0053] The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments of a jet pump for non-contact intraocular pressure measurement as defined in the claims. While various embodiments of the claimed subject matter have been described above with some detail or with reference to one or more individual embodiments, those skilled in the art could make numerous modifications to the disclosed embodiments without departing from the spirit or scope of the claimed subject matter. For example, the jet pump could be used to generate controlled puffs of gases other than ambient air, including, but not limited to, oxygen, nitrogen, helium, and argon, or gases containing colorants, odorants, drugs, or other materials. Additionally, some or all of the components of the jet pump may be housed within a housing, either alone or together with other components, such as a battery and / or power source.

[0054] Still other embodiments are contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings be interpreted as exemplification of particular embodiments, and not in a limiting sense. Changes in detail or structure may be made without departing from the basic elements of the subject matter defined in the following claims. Those skilled in the art will recognize that the above-described devices, systems, and methods may be modified in various ways not expressly described or suggested above. Accordingly, those skilled in the art will understand that the embodiments encompassed by the present disclosure are not limited to the specific exemplary embodiments described above. In that regard, while exemplary embodiments have been shown and described, a wide range of modifications, changes, and substitutions are contemplated in the foregoing disclosure. It is understood that such variations can be made to the foregoing without departing from the scope of the present disclosure. It is therefore appropriate that the appended claims be construed broadly and consistent with the present disclosure.

Claims

1. 1. A system for determining intraocular pressure (IOP) of an eye, comprising: a pump configured to generate an air puff; a nozzle in communication with the pump and configured to direct the air puff along a first axis toward the eye; a light source disposed distal to the nozzle and oriented to emit a light beam along a second axis transverse to the first axis toward a first linear light sensor, the light beam having a width on the first axis such that a first portion of the light beam illuminates an outer surface of the eye and a second portion of the light beam passes through a front surface of the eye; a first linear optical sensor disposed distal to the nozzle and configured to receive the second portion of the light beam; A system comprising:

2. The system of claim 1 , wherein the first linear optical sensor comprises a linear array of sensor elements arranged along a third axis.

3. The system of claim 1 , wherein the light source comprises an optical element and a collimating lens configured to collimate the light beam along at least one axis.

4. The system of claim 1 , further comprising a collimating lens coupled to the linear photosensor, the collimating lens configured to focus the light beam linearly toward the linear photosensor.

5. The system of claim 4 , wherein the collimating lens is positioned adjacent to the linear photosensor.

6. 10. The system of claim 1, further comprising a second linear photosensor positioned adjacent to the first linear photosensor, the first linear photosensor and the second linear photosensor being oriented toward the light source in a fourth axis.

7. The system of claim 6 , wherein the fourth axis is parallel to the second axis.

8. receiving a first plurality of displacement measurements taken over a first time period from the first linear optical sensor; determining an intraocular pressure of the eye based on the first plurality of displacement measurements and the first time period; The system of claim 1 , further comprising a processor configured to:

9. the processor: receiving a second plurality of displacement measurements from the first linear optical sensor taken over a second time period preceding the first time period; Detecting a blink based on the second plurality of displacement measurements and the second time period; The system of claim 8 , further configured to cause the linear optical sensor to obtain the first plurality of displacement measurements based on detecting the blink.

10. a drug delivery module positioned and oriented to release a flow of drug into the eye; the processor: causing the drug delivery module to release the flow of the agent into the eye; receiving a third plurality of displacement measurements from the linear optical sensor taken over a third time period; The system of claim 8 , further configured to determine whether the flow of the agent has reached the eye based on the third plurality of displacement measurements.

11. 9. The system of claim 8, further comprising a third optical sensor oriented toward the first axis, wherein the processor is configured to determine whether the eye is located within a measurement range of the nozzle based on proximity measurements from the third optical sensor.

12. The system of claim 1 , wherein the first linear photosensor comprises a one-dimensional array of photodiodes.

13. The system of claim 1 , wherein the first linear photosensor comprises a two-dimensional array of photodiodes.

14. The system of claim 1 , wherein the light source is configured to emit light having a center wavelength within the visible spectrum.

15. 1. A method for measuring intraocular pressure (IOP) in an eye of a patient, comprising: generating an air puff having a pressure and directed along a first axis toward a cornea of ​​the patient's eye; emitting, by a light source, a light beam along a second axis transverse to the first axis toward a first photosensor array, the light beam including a width on the first axis such that a first portion of the light beam illuminates an outer surface of the eye and a second portion of the light beam passes through a front surface of the eye; detecting a width of the second portion of the light beam with the first photosensor array; determining the IOP of the patient's eye based on the detected width of the second portion of the light beam and the pressure of the air puff; A method comprising:

16. detecting the width of the second portion of the light beam; receiving a first plurality of displacement measurements over a period of time from the first photosensor array; 16. The method of claim 15, wherein said determining said IOP is based on said first plurality of displacement measurements.

17. determining the IOP, determining flattening of the cornea; 17. The method of claim 16, wherein the determining the IOP is based on timing of the corneal flattening.

18. 18. The method of claim 17, wherein determining the timing of the flattening of the cornea comprises determining a maximum displacement based on the first plurality of displacement measurements.

19. receiving a second plurality of displacement measurements taken over a first period of time from the first photosensor array; detecting a blink based on the second plurality of displacement measurements; causing the first photosensor array to obtain the first plurality of displacement measurements at a second time after the first period of time based on detecting the blink; 17. The method of claim 16, further comprising:

20. detecting the pressure of the air puff with a pressure sensor; 16. The method of claim 15, further comprising:

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