Determining the standoff distance to the eyes

Abstract

The purpose is to assist in determining the distance between the eye and a reference point. [Solution] A system, device, and method for determining the standoff distance to the eye are provided. In one example, the system may include a structure along a first axis toward the eye, a linear sensor array, and a light source that emits a light beam toward the linear sensor array along a second axis. The light beam may have a width such that a first portion of the light beam illuminates the outer surface of the eye and a second portion of the light beam passes in front of the eye. Based on the measurement of the second portion, the system may determine the standoff distance between the structure along the first axis and the eye. Another example may include an ultrasonic transducer assembly for emitting an ultrasonic pulse toward the eye and detecting the reflection of the pulse to determine the standoff distance.

Description

TECHNICAL FIELD

[0001] (Field of the Invention) The present disclosure relates generally to devices and methods for performing measurements involving the eye, and specifically to devices and methods for determining a standoff distance to the eye. Other aspects are also described.

BACKGROUND ART

[0002] In many applications, it is important to determine the position or location of the eye relative to a reference point, such as a structure or instrument. For example, in air puff tonometry, the location of the eye relative to the nozzle that delivers air and the optical measurement instrument being utilized can be critical to obtaining accurate results. In another example, for retinal imaging, the location of the eye relative to the imaging instrument, for example within 1 millimeter (mm), can be critical to obtaining a clear image of the fundus. In non-ophthalmic diagnostic applications, the location of the eye may be important for augmented reality (AR) and / or virtual reality (VR) applications to accurately determine the eye relief relative to eyeglasses or a headset to minimize eye strain and / or maximize optical performance.

SUMMARY OF THE INVENTION

[0003] Implementations of the present disclosure include determining a standoff distance to the eye (between the eye and a structure that serves as a reference point, such as a nozzle for delivering a jet of air). In one example, the system may include a structure disposed along a first axis toward the eye, a linear sensor array disposed distal to the structure, and a light source directed toward the linear sensor array along a second axis. The light beam may have a width (e.g., along the first axis) such that a first portion of the light beam illuminates the outer surface of the eye and a second portion of the light beam passes in front of the eye. Based on measurements of the second portion, the system may determine the standoff distance between the structure and the eye along the first axis. Another example may include an ultrasonic transducer assembly directed to emit ultrasonic pulses toward the eye and to detect reflections of the ultrasonic pulses from the eye. The ultrasonic transducer assembly may be configured to emit ultrasonic pulses and detect reflections within a field of view that includes the eye and excludes the nose and forehead near the eye. The system may measure the time of flight based on the difference between a first time corresponding to the emission of an ultrasonic pulse and a second time corresponding to the detection of the reflection. The system may then determine the standoff distance between the structure and the eye along a first axis based on the time of flight. Other embodiments are also described and claimed.

[0004] The above summary does not constitute an exhaustive list of all embodiments of this disclosure. This disclosure is intended to include all systems and methods that can be implemented from all appropriate combinations of the various embodiments summarized above, as well as those disclosed in the following “Modes for Carrying Out the Invention” and specifically pointed out in the “Claims” section. Such combinations may have specific advantages not specifically described in the above summary. [Brief explanation of the drawing]

[0005] Some aspects of the disclosure herein are illustrated in the accompanying drawings as examples rather than limitations, where similar references indicate similar elements. It should be noted that references to “an” or “one” aspects in this disclosure do not necessarily refer to the same aspect, but rather mean at least one. Furthermore, for brevity and to reduce the total number of figures, a given figure may be used to illustrate features of two or more aspects of this disclosure, and not all elements in the figure may be required for the given aspect. [Figure 1] This is a perspective view of an ophthalmic device according to at least one embodiment of the present disclosure. [Figure 2] This is a schematic diagram of an ophthalmic device having an array-based optical measurement subsystem according to at least one embodiment of the present disclosure. [Figure 3] This is a top view of an ophthalmic device having an array-based optical measurement subsystem according to at least one embodiment of the present disclosure. [Figure 4] This is a front view of an ophthalmic device having a nozzle, a proximity sensor, and an array-based optical measurement subsystem, according to at least one embodiment of the present disclosure. [Figure 5] This is a schematic diagram of an ophthalmic device having an array-based optical measurement subsystem according to at least one embodiment of the present disclosure. [Figure 6] This is a schematic diagram of an ophthalmic device having an array-based optical measurement subsystem according to at least one embodiment of the present disclosure. [Figure 7] This is a schematic diagram of an ophthalmic device having an array-based optical measurement subsystem according to at least one embodiment of the present disclosure. [Figure 8] This is a front view of an ophthalmic device having a nozzle, a proximity sensor, and an array-based optical measurement subsystem, according to at least one embodiment of the present disclosure. [Figure 9] This is a graph showing the displacement-time relationship of the cornea deflected in response to a jet of air from an ophthalmic instrument, according to at least one embodiment of the present disclosure. [Figure 10]This is a schematic diagram of an ophthalmic device utilizing an ultrasound measurement subsystem according to at least one embodiment of the present disclosure. [Figure 11] This is a perspective view of an ultrasonic optical measurement subsystem of an ophthalmic device according to at least one embodiment of the present disclosure. [Figure 12] This is a front view of an ultrasonic measurement subsystem according to at least one embodiment of the present disclosure. [Modes for carrying out the invention]

[0006] Standoff distance, or eye standoff, or simply standoff, generally refers to the distance between an eye and a reference point. Standoff distance can be a useful measure for determining the position of an eye. For example, in the case of eye diagnosis, the standoff distance may be determined by using a chin rest and head fixation device that minimizes the patient's head movement. The operator can then determine the standoff distance using a camera or other optical imaging device by looking through an eyepiece. If the standoff distance needs to be controlled, the operator can adjust the spacing via a joystick or other device. However, this approach may involve the operator's skill and time to perform the measurement and / or adjustment. For example, determining and / or adjusting the standoff distance may depend on the operator's performance. Furthermore, this approach may involve the implementation of large optical components that can be cumbersome to deploy. Additionally, this approach may be inconvenient for the patient when using head fixation devices.

[0007] In some cases, the system can fix the standoff distance to a reproducible value based on the mechanical design of the device or equipment. For example, AR and / or VR glasses can fix the standoff distance to a reproducible value when worn by the user. However, this approach may not allow for resolution of standoff distances greater than a few millimeters. Additionally, during exercise or other activities, the glasses or headset may slip due to the user's movements and / or sweat.

[0008] When a camera is used to determine the standoff distance, the system may require advanced algorithms and hardware to obtain the standoff distance in real time. However, the frame rate in non-scientific grade imaging sensors is typically limited to 100 frames per second (FPS) in a given region of interest, which may not be sufficient to achieve the required temporal resolution. Additionally, latency associated with signal acquisition and processing can introduce delays into the system.

[0009] Implementations of the present disclosure address such problems by utilizing a linear sensor array or an ultrasonic transducer assembly to determine the standoff distance to the eye (e.g., eye standoff, or simply standoff). For example, the standoff distance can be measured between a structure acting as a reference point, such as a nozzle for delivering a jet of air, and the eye. Some implementations may include a structure disposed along a first axis toward the eye, a linear sensor array disposed distal to the structure, and a light source directed to emit a light beam toward the linear sensor array along a second axis. The light beam may have a width (e.g., along the first axis) such that a first portion of the light beam illuminates the outer surface of the eye and a second portion of the light beam passes in front of the eye. A processor executing instructions stored in memory can determine the standoff distance between the structure along the first axis and the eye based on a measurement of the second portion. Another example may include an ultrasonic transducer assembly directed to emit an ultrasonic pulse toward the eye and to detect the reflection of the ultrasonic pulse from the eye. An ultrasonic transducer assembly may be configured to emit ultrasonic pulses and detect reflections within a field of view that includes the eye but excludes the nose and forehead near the eye. A processor executing instructions stored in memory may measure the time of flight based on the difference between a first time corresponding to the emission of the ultrasonic pulse and a second time corresponding to the detection of the reflection. The processor may then determine the standoff distance between the structure and the eye along a first axis based on the time of flight.

[0010] In some implementations, the systems described herein can enable automated measurement of eye standoff (e.g., standoff distance) without operator involvement. The system can utilize line sensors to measure the laser beam profile. In some implementations, the laser may be near-infrared, where the user would not perceive the illumination, but at wavelengths (e.g., 700 nanometers (nm) to 1000 nm) for which silicon sensors are relatively inexpensive and / or widely available. In some implementations, line sensors can be read out at speeds exceeding 1000 FPS while being relatively inexpensive and / or widely available. In some implementations, only a single line profile is analyzed, simplifying the need for software to analyze a two-dimensional image.

[0011] In some implementations, the system can emit a parallel beam that enters a lens that magnifies the beam within a one-dimensional beam fan. The position of the eye can be determined depending on its position within the beam fan. For example, the system can use a cylindrical lens or a Powell lens. The beam can be collimated in a plane so that it is approximately at the same height as the image pixels on the line sensor. The eye may initially be outside the beam and, as a result, outside the measurement range. Subsequently, the eye may move inside the beam and, as a result, move inside the measurement range, enabling the measurement of the standoff distance. For example, a line sensor in the setup may allow the eye's location to be determined by observing the output profile on the sensor.

[0012] In some implementations, the system may include two cylindrical lenses positioned on either side of the eye at an appropriate angle. In some implementations, the system may emit a beam in a collimated line, for example, instead of a beam fan. In some implementations, the system may emit a beam collimated to a large size or diameter in multiple dimensions (e.g., at least 10-20 mm in each dimension). In some implementations, additional optical components in the form of rod lenses may be used to focus the light in one dimension onto the line sensor. Such implementations can advantageously provide insensitivity to misalignment in multiple dimensions. In some implementations, the system may emit a beam collimated to a large size or diameter in only one dimension, with the narrow dimension being parallel to the linear array. This can advantageously eliminate the need for rod lenses while accepting misalignment in the axis parallel to beam propagation rather than with respect to other transverse axes.

[0013] In some implementations, the system may utilize a laser diode. In some implementations, the system may utilize a light-emitting diode (LED) instead of a laser diode. In some cases, the beam angle may be modified to suit the mechanical requirements of the instrument or the ergonomic requirements of the subject or patient; for example, the normal to the corneal surface may not be perpendicular to the optical axis. Since the acquisition speed in the system may be fast, the system may inform the operator whether the acquired data is valid or invalid. For example, in fundus examination, if the user's eye has moved outside the eye box when the frame is captured, the measurement may be discarded. The system described herein can advantageously avoid this situation. In some cases, the system may also be used to calibrate the standoff distance to obtain better resolution. For example, in air-puff intraocular tonometry, determining the eye position during data acquisition may allow the operator to calibrate the points on the acquisition curve.

[0014] In some implementations, the system may utilize a pair of ultrasonic transducers (for example, one as a receiver and one as a transmitter). The system uses time of flight to determine the position of the eye. A pulse is transmitted by the transmitter. A portion of the pulse is returned by the eye via reflection. Other reflections corresponding to echoes can be filtered out and ignored. The distance between the eye and the transmitter can be determined by measuring the time difference between the transmitted pulse and the received pulse.

[0015] In some implementations, the field of view of the ultrasonic sensor may be narrow to avoid measuring the forehead or nose when measuring the distance to the eye. The system's transducer can operate at frequencies of several hundred kHz, and based on the short distance between the eye and the device (e.g., less than 2 inches), the refresh rate can be high without undesirable aliasing.

[0016] In some implementations, transducers may be arranged side-by-side. In some implementations, transducers may point inward based on the minimum distance for capturing reflected signals at the receiver. In some implementations, the receiver and transmitter may be concentric with respect to each other. In some implementations, the system may include a focused transducer array based on sensitivity and / or range requirements. In some implementations, time-of-flight measurements may be performed with a single transducer using appropriate electrical switching between transmit and receive modes. In some implementations, the back of the transducer may be covered with an absorbent material such as epoxy impregnated with tungsten powder to allow for the rapid ring-down of the transducer. This shortens the transmit pulse, thereby allowing the echo to attenuate before it arrives from a nearby object. In some implementations, two transducers may be used, designed to resonate at 400 kHz and impedance-matched to air.

[0017] Next, several aspects of the present disclosure will be described with reference to the accompanying drawings. Unless the shape, relative position, and other aspects of the described components are explicitly defined, the scope of the present invention is not limited only to the components shown for illustrative purposes. Also, while many details are set forth, it will be understood that some aspects of the disclosure may be practiced without these details. In other instances, well-known circuits, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.

[0018] Figure 1 is a perspective view of an ophthalmic apparatus, for example, a non-contact tonometer 100. The tonometer 100 is an example of an apparatus that may be configured to determine a standoff distance to an eye. In some cases, the standoff distance may be the distance to a structure (e.g., a reference point) along an axis that is perpendicular (e.g., normal or orthogonal) to the eye. In other cases, the standoff distance may be the distance to a structure along an axis at a non-perpendicular angle (e.g., not normal) to the eye. The tonometer 100 includes a housing 102 that encloses and / or supports a plurality of 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 features for more consistently and repeatedly positioning a user's eye near the eye cup 134. The adjustment dial 106 may be configured to make adjustments in one or more axes to position the user's eye within an acceptable position range near the eye cup 134. In some aspects, the adjustment dial 106 may be used to switch from a left eye position to a right eye position and vice versa.

[0019] The tonometer 100 further includes a light source 130 and a sensor array 132 for determining the standoff distance. In some embodiments, the tonometer 100 may include an ultrasonic transducer assembly for determining the standoff distance, including one shown in Figure 10. The light source 130 is positioned and oriented to project a light beam across the eye in a direction perpendicular to the optical axis of the eye. Similarly, the sensor array 132 is positioned to collect at least a portion of the light from the light source 130, and the collected light travels across the optical axis of the eye. In some embodiments, the sensor array 132 is configured to receive portions of light that are not obscured by the user's eye / cornea (e.g., portions of light that pass in front of the user's eye / cornea). When the eye is moved into the light beam relative to, for example, an eye cup 134, a smaller amount of light from the light source 130 may reach the sensor array 132. Furthermore, when the eye is moved out of the light beam, a larger amount of light from the light source 130 may reach the sensor array 132. In addition, when a jet or puff of air is delivered through the eye cup 134, the cornea may be flattened or compressed. Therefore, at the moment the cornea is deflected or compressed to allow more light to pass through, more light from the light source 130 may reach the sensor array 132. In some embodiments, the sensor array includes a plurality of sensor elements positioned along the z-axis or optical axis. The z-axis can be described as being parallel to the direction in which the air puff is delivered and / or parallel to the optical axis of the eye, for example, perpendicular to the eye. Therefore, the number of sensors in the array that align at least a threshold amount of light may correspond to the position of the eye and / or the deflection of the cornea. Thus, the position of the eye and / or the deflection or compression of the cornea by the air puff over the period during which the eye receives the air puff may be determined based on readings from the sensor array 132.

[0020] The light source 130 and the sensor array 132 may be included in the housing 102, controlled by a processor or controller to execute instructions stored in a memory. In some cases, the light source 130 and the sensor array 132 may be controlled together to determine the standoff distance between the structure along the first axis and the eye. For example, the standoff distance can exist between the eye and a structure that functions as a reference point, such as a nozzle for delivering an air puff. The standoff distance may be measured with a resolution of less than 1 mm. In some cases, the light source 130 and the sensor array 132 may be controlled together with the air puff generator components (e.g., a pump, a valve, etc.) such that the light source 130 and the sensor array 132 are activated during the period when the air puff impinges on the cornea. The light source 130 may be configured to generate a parallel beam having a width of 5 mm to 30 mm at least along the z-axis. In some embodiments, the parallel beam is 10 mm to 20 mm wide along the z-axis. In some embodiments, the parallel beam is cylindrical. In other embodiments, the parallel beam is elliptical, flat, converging, diverging, or of 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.

[0021] The tonometer 100 may be a benchtop or desktop tonometer device. In some embodiments, the tonometer 100 is configured for home use so that a patient can use the tonometer 100 without the supervision or assistance of a physician. The tonometer 100 may include one or more user controls for performing eye position measurements (e.g., standoff distance to a structure such as a nozzle) and / or intraocular pressure (IOP) measurements (e.g., corneal deflection). The tonometer 100 may also include a user interface device for displaying indications, providing feedback to the user or proper positioning of the eye along the air puff axis, displaying IOP measurements, and / or providing any other suitable interface functions. A tonometer configured for home use may be desirable and is advantageous in some embodiments. For example, accurate, frequent, and more recent IOP measurements may enable more adapted or more personalized treatment regimens. In this regard, if a patient obtains more measurements throughout the day at various times, the patient may obtain more information about the patient's IOP variability throughout the day. Therefore, physicians and patients can create treatment schedules or regimens that are more accurately suited to the patient's indications. In other embodiments, the tonometer 100 may be configured for use by a physician, for example, in the office of an ophthalmologist or optometrist. In other embodiments, the tonometer 100 may be a mobile or portable device. For example, the tonometer 100 may be configured for handheld operation. For example, the tonometer 100 may include a rechargeable battery so that it can be used without being plugged into a power outlet.

[0022] Figure 2 is a schematic diagram of an ophthalmic device (e.g., a tonometer 100). The tonometer 100 shown in Figure 2 may, in some embodiments, be similar to the tonometer 100 shown in Figure 1. In this regard, the tonometer 100 shown in Figure 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 moves along an axis 125. The axis 125 may be aligned with 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. In some cases, the nozzle 122 may include a structure that functions as a reference point for determining the standoff distance to the eye. In other cases, a different structure (e.g., a light sensor 136) may be used.

[0023] The tonometer 100 further includes a drug delivery module 140 configured to deliver or administer a drug to the patient's eye. For example, the drug delivery module 140 may be configured to generate a flow or mist of ophthalmic fluid into the eye as part of a treatment regimen. In some embodiments, drug delivery by the module 140 may be based on IOP measurements obtained by the tonometer 100. The tonometer 100 further includes a light sensor 136 distinct from the sensor array 132. In some embodiments, the light sensor 136 may be configured for proximity measurement. For example, the light sensor 136 may be configured to determine whether the eye is within a suitable range of the nozzle 122. In some embodiments, the light sensor 136 may be controlled by a controller 110 to determine whether a user is present in the tonometer to activate the components of the tonometer 100. In some embodiments, the light sensor 136 may be used for blink detection. In this regard, the controller 110 may be configured to detect blinking based on optical measurements from the photosensor 136 and to activate the pump 120 and / or nozzle 122 after detecting a blink. In some embodiments, the pump 120 may include a valve, and the controller 110 may be configured to activate the valve to release an air puff. In other embodiments, the controller 110 may use a light source 130 and a photosensor array 132 to detect blinking. For example, the controller 110 may detect a momentary increase in the corneal profile based on signals from the photosensor array and determine that a blink has occurred.

[0024] The controller 110 can determine the standoff distance between a structure along axis 125 and the eye based on measurements of the light beam from the light source 130, through the eye, and reaching the sensor array 132. For example, the standoff distance may be a measurement between a structure acting as a reference point (e.g., a nozzle 122) and the eye. In some cases, the measurement can be performed when the eye is within a range determined by the optical sensor 136.

[0025] The controller 110 can also determine the deflection of the eye based on the measurement of the light beam from the light source 130 that passes through the eye and reaches the sensor array 132. For example, the pressure applied to the cornea by the air puff is increased over a short period of time (15 milliseconds in one embodiment) until it is sufficient to cause a temporary flattening or planarization of the cornea, followed by a slight indentation for a short time. The pressure can then be decreased over a period of time (e.g., 15 milliseconds) so that the cornea flattens again before returning to its normal shape. At both moments of flattening, the tonometer 100 can detect the flattening.

[0026] In one embodiment, the static pressure of the air puff on the center of the cornea reaches a pressure approximately 30 mmHg (4.0 kPa or 0.04 atm) higher than the ambient pressure with an accuracy of approximately ±1 mmHg or less than ±1 mmHg. For example, the accuracy of the pressure of the air puff produced by the pump 120 and nozzle 122 may be ±0.05 mmHg, ±0.1 mmHg, ±0.5 mmHg, or any other preferred accuracy. Assuming the patient's IOP is somewhere between 5 mmHg and 30 mmHg, the air puff may produce two distinct applanation events, one during the rising time and one during the falling time. In some embodiments, the tonometer 100 may further include one or more pressure sensors in the pump 120, in the nozzle 122, and / or at any other preferred location to monitor the pressure of the air puff ejected through the nozzle 122. The controller 110 that receives these measurements then has two separate IOP readings, which may be reported separately, averaged, or otherwise.

[0027] The tonometer 100 includes a controller 110 and a memory 112 that communicates with the controller 110. The memory 112 may store instructions that can be executed by the memory 112 to perform one or more of the functions described above. In some embodiments, the memory 112 may further store standoff distance (e.g., eye position), IOP measurements, patient-related data, and / or any other preferred type of information. In some embodiments, the memory 112 may store treatment-related data for generating treatment alerts or indicators for the patient. For example, the memory 112 may store general and / or patient-specific IOP thresholds for determining whether to output an alert to the user or network, or whether to allow the drug delivery module 140 to deliver a drug to the patient's eye.

[0028] Figure 3 is a top view of an ophthalmic device (e.g., a tonometer 100) having a transverse array-based optical measurement subsystem according to at least one embodiment of the present disclosure. The tonometer 100 includes a pump 120 and a nozzle 122 coupled to a first housing portion 101. The pump 120 and / or nozzle 122 may include a structure that functions as a reference point for determining the standoff distance to the eye. The 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 105. The first housing portion 101 is coupled to the second housing portion 103 by a first connector element 109, and the first housing portion 101 is coupled to the third housing portion 105 by a second connector element 107. In some embodiments, connector elements 107, 109 are adjustable to adjust the position of the light source 130, the sensor array 132, and / or the focusing element 138 (for example, a collimating lens such as a rod lens or cylindrical lens, positioned after the eye 10 and adjacent to the sensor array 132). For example, in some embodiments, the connector elements 107, 109 may include telescopic features, sliding clamps, rack and pinion mechanisms, hinges, and / or any other suitable adjustment mechanisms.

[0029] 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 pneumatic characteristics. Light source 130 is configured to generate a light beam 50 in a direction transverse or perpendicular to axis 125. In some embodiments, it will be understood that the beam 50 does not have to be exactly perpendicular to axis 125. For example, the beam 50 may be centered along an axis or direction that is 75° to 105° with respect to axis 125. In Figure 3, the beam 50 is collimated along the x-axis. 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 (e.g., configured to emit light in the visible light spectrum). In some embodiments, light source 130 may include an LED.

[0030] In some implementations, the beam 50 has width or thickness in at least the direction of the first axis 125. Thus, the beam 50 strikes the eye 10 in a range of depths that includes the cornea. The first portion of the beam 50 (e.g., the portion of light that illuminates the outer surface of the user's eye / cornea) is obscured by the eye, while the second portion of the beam 50 that is not obscured by the eye 10 (e.g., the portion of light that passes in front of the user's eye / cornea) continues to travel forward 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 type of focusing element. The focusing element 138 is configured to focus the beam 50 in at least one axis. For example, in Figure 3, the focusing element 138 is configured to focus the beam 50 in the y-axis (e.g., into a thin line toward the sensor array 132) but not in the z-axis. In this regard, the focusing element 138, positioned in close proximity to the sensor array 132, can tolerate some misalignment of the eye in the y-axis. For example, since the beam 50 has width in the y-axis, there may be a range of suitable positions in the y-axis that allows the sensor array 132 to obtain accurate measurements of the standoff distance from the reference point to the eye, the corneal profile, and / or deflection.

[0031] The sensor array 132 includes a plurality of sensor elements arranged along the z-axis (parallel to axis 125). In the illustrated embodiment, the 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 the elements of array 132 may be small enough to detect the position of the eye with a high resolution, for example, less than 1 mm, indicating the standoff distance of the eye to a reference point. The width and spacing of the elements of array 132 may also be small enough to detect a range of deflection indicating the range of lOP. For example, each element of array 132 may have a sensor width in the range of 2 μm to 50 μm and an inter-element spacing in the range of 3 μm to 60 μm. The elements may 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 the eye / corneal position relative to array 132 and beam 50. Array 132 may include any preferred number of elements, including 20, 48, 64, 128, 256, 512, 1024, and 2048, and / or any other preferred number of elements, more or less than these. In some embodiments, the elements of array 132 include photodiodes configured to convert received light into 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 signals from each of the electrical elements and transmits the signals to a controller (e.g., controller 110, Figure 1). In one embodiment, array 132 includes a Hamamatsu SI1639-01 (having 2048 pixels with a width of 14 μm and a total sensor width of 28.672 mm).

[0032] In some embodiments, the sensor array 132 may be configured to provide signals indicating the voltage and / or current of each element of the array 132. In other embodiments, the sensor array 132 may be configured to provide a signal for each element indicating a binary value representing whether the sensor element has received light exceeding a threshold amount. Thus, the signals provided by the array 132 may indicate the number of sensor elements illuminated by the light source 130, based on the position of the eye in the light beam and / or corneal flattening or deflection. Based on the position, the tonometer 100 can determine the standoff distance to the eye (e.g., the distance between the eye and the nozzle 122, which acts as a reference point, along the axis to the eye). Additionally, based on the timing of corneal flattening and the known pressure and characteristics of the air puff, the tonometer 100 can determine the IOP. In this regard, since the light beam 50 strikes the cornea from the side, the tonometer 100 can determine the time from when the air puff reaches the cornea until the lateral corneal measurement first reaches its minimum value.

[0033] Figure 4 is a front view of an ophthalmic device (e.g., a tonometer 100) shown in Figure 3, according to 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 101 to which a nozzle 122, a drug delivery module 140, and a user alignment feature 124 are coupled. In some embodiments, the housing portion 101 may include an eye cup. However, the eye cup 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 distribution nozzle for generating a flow or mist of drug. The user alignment feature 124 may include a display, screen, mirror, and / or any other suitable feature for guiding the user to position the eye / cornea in an acceptable position for performing standoff distance measurement and / or IOP measurement. For example, the user alignment feature 124 may include a set of crosshairs, circles, reticles, or any other suitable type of shape, where overlapping shapes indicate that the user's eye is correctly positioned on at least one of the axes. In some implementations, the nozzle 122 may include a reference point for measuring the standoff distance. In some implementations, the user alignment feature 124 may include a reference point.

[0034] Figure 5 is a schematic diagram of an ophthalmic device (e.g., a tonometer 200) having a transverse array-based optical measurement subsystem according to another embodiment of the present disclosure. Similar to the tonometer 100 shown in Figure 3, the tonometer 200 shown in Figure 5 includes a nozzle 222, a light source 230, and a sensor array 232. The nozzle 222 may include a structure that functions as a reference point for determining the standoff distance to the eye. The nozzle 222, the light source 230, and the sensor array 232 may be coupled to their respective housing portions, similar to the embodiment shown in Figure 3. Furthermore, the position and 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 Figure 5, there is no focusing element.

[0035] The nozzle 222 may be configured to generate a puff or jet of air along the axis 225. The air puff may have a controlled profile, pressure, duration, velocity, and / or any other pneumatic characteristics. The light source 230 is configured to generate a light beam 50 in a direction transverse or perpendicular to the axis 225. In some embodiments, it will be understood that the beam 50 does not have to be exactly perpendicular to the axis 225. For example, the beam 50 may be centered along an axis or direction that is 75° to 105° with respect to the axis 225. In Figure 5, the beam 50 is collimated along the x-axis. For example, in some embodiments, the 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 (e.g., configured to emit light in the visible light spectrum). In some embodiments, the light source 230 may include an LED.

[0036] In some implementations, the beam 50 has a width or thickness in at least the direction of the first axis 225. Thus, the beam 50 strikes the eye 10 in a depth range that includes the cornea. The portion of the beam 50 not obscured by the eye 10 (e.g., the portion of light passing in front of the user's eye / cornea) continues to travel forward toward the sensor array 232. In some embodiments, the absence of a focusing element in the embodiment of Figure 5 may reduce the error or misalignment of the eye position compared to, for example, the embodiment shown in Figure 3.

[0037] As described above with respect to Figure 3, the sensor array 232 includes a plurality of sensor elements arranged along the z-axis (parallel to axis 225). In the embodiment illustrated, the 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 the elements of array 232 may be small enough to detect the position of the eye with a high resolution, for example, less than 1 mm, indicating the standoff distance of the eye to a reference point. The width and spacing of the elements of array 232 may also be small enough to detect a range of deflection indicating the range of lOP. For example, each element of array 232 may have a sensor width in the range of 2 μm to 50 μm and an inter-element spacing in the range of 3 μm to 60 μm. Array 232 may include any preferred number of elements, including 20, 48, 64, 228, 256, 512, 1024, 2048, and / or any other preferred number of elements, more and less than these. In some embodiments, the sensor array 232 may include multiple rows of sensor elements stacked along the y-axis. For example, the sensor array 232 may comprise a two-dimensional array.

[0038] Similar to tonometer 100, tonometer 200 may include a controller configured to determine the standoff distance to the eye (e.g., the position of the eye / cornea on the y-axis) based on signals from a two-dimensional array. For example, the standoff distance may be a measurement between the eye and a structure acting as a reference point (e.g., nozzle 222). The controller may also be configured to determine the amount and / or timing of corneal deflection based on signals from the two-dimensional array and the determined position on the y-axis.

[0039] Figure 6 is a schematic diagram of an ophthalmic device (e.g., a tonometer 300) having a transverse array-based optical measurement subsystem according to another embodiment of the present disclosure. Similar to the tonometer 100 shown in Figure 3, the tonometer 300 shown in Figure 6 includes a nozzle 322, a light source 330, a sensor array 332, and a focusing element 338 (e.g., a collimating lens such as a cylindrical lens or a Powell lens, positioned in front of the eye 10 and adjacent to the light source 330). The nozzle 322 may include a structure that functions as a reference point for determining the standoff distance to the eye. The nozzle 322, light source 330, sensor array 332, and focusing element 338 can be coupled to their respective housing portions, similar to the embodiment shown in Figure 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 Figure 6, the focusing element 338 is positioned close to the light source 330 instead of close to the sensor array 332.

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

[0041] In some implementations, 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 in a depth range that includes the cornea. A portion of the beam 50 that is not obscured by the eye 10 (e.g., a portion of the light that passes in front of the user's eye / cornea) continues to travel forward toward the sensor array 332. In some embodiments, the beam 50 may have a focal point in or near the sensor array 332. Thus, the beam 50 may converge between the focusing element 338 and the sensor array 332.

[0042] As described above with respect to Figure 3, the sensor array 332 includes a plurality of sensor elements arranged along the z-axis (parallel to axis 325). In the embodiment illustrated, the sensor array 332 is a one-dimensional linear sensor array. Each element of the array 332 may have a width along the z-axis and a spacing along the z-axis. The width and spacing of the elements of the array 332 may be small enough to detect the position of the eye with a high resolution, for example, less than 1 mm, indicating the standoff distance of the eye to a reference point. The width and spacing along the array 332 may also be small enough to detect a range of deflection indicating the range of lOP. For example, each element of the array 332 may have a sensor width in the range of 2 μm to 50 μm and an inter-element spacing in the range of 3 μm to 60 μm. The array 332 may include any preferred number of elements, including 20, 48, 64, 328, 256, 512, 1024, 2048, and / or any other preferred number of elements, more and less than these.

[0043] Figure 7 is a schematic diagram of an ophthalmic device (e.g., a tonometer 400) having a transverse array-based optical 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 (e.g., a collimating lens such as a cylindrical lens or a Powell lens, positioned in front of the eye 10 and adjacent to the light source 430). The nozzle 422 may include a structure that functions as a reference point for determining the standoff distance to the eye. The nozzle 422, light source 430, sensor array 432, and focusing element 438 can be coupled to their respective housing portions, similar to the embodiment shown in Figure 3. Furthermore, the position and / or orientation of the light source 430 and the sensor array 432 may be adjustable by adjustable connecting components of the housing, similar to those described above.

[0044] In the embodiment of Figure 7, the beam 50 generated by the light source 430 is a divergent beam. In some embodiments, the light source 430 is configured to emit light as a divergent beam (e.g., a beam fan). In other embodiments, the light source 430 includes one or more optical components (e.g., lenses, mirrors) configured to generate the divergent beam 50 based on the light emitted by the light source 430. The tonometer 400 includes a focusing element 438 adjacent to the light source 430. The focusing element 438 is configured to focus the divergent beam 50 in the y-axis to generate a fan-shaped beam that diverges in the z-axis and converges in the y-axis. Thus, the focused beam 50 includes a width or thickness in the direction of a first axis 425 that increases as the beam 50 approaches the sensor array 432. The beam 50 strikes the eye 10 in a range of depths including the cornea. In some embodiments, the divergent nature of the beam 50 can amplify variations in the amount of light reaching the sensor array 432 depending on the position of the eye and / or the cornea compressed by the air puff. For example, if the cornea is compressed by 4 mm, the width 442 of the portion of the beam 50 received by the sensor array 432 may change by 4.5 mm. In another embodiment, if the cornea is compressed by 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 preferred amount. The more significant the change in width 442 based on the diverging beam, the better the resolution of the standoff distance measurement and / or corneal deflection measurement may be. For example, a more significant change in width 442 may increase the number of sensor elements receiving the rays of the beam 50 due to the position of the eye and / or the compression or deflection of the cornea.

[0045] Figure 8 is a front view of an ophthalmic device (e.g., a tonometer 500) according to an embodiment of the present disclosure. The tonometer 500 includes a light source 530 positioned opposite sensor arrays 532a, 532b and configured to project a light beam toward them. The tonometer 500 includes a focusing element 538 (e.g., a collimating lens positioned behind the eye 10 and adjacent to the sensor arrays 532a, 532b) for focusing the light beam from the light source 530 onto the sensor arrays 532a, 532b. 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, screen, mirror, and / or any other preferred feature for guiding the user to position the cornea in an acceptable position for performing IOP measurement. For example, the user alignment feature 524 may include a set of crosshairs, circles, or any other preferred type of shape, where overlapping shapes indicate that the user's eye is correctly positioned on at least one of the axes. In some implementations, the nozzle 522 may include a reference point for measuring the standoff distance. In some implementations, the user alignment feature 524 may include a reference point.

[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 and 532b may be identical or arranged in a stacked relationship on the y-axis. In other embodiments, the sensor arrays 532a and 532b may be different sensor arrays. In other embodiments, three or more 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. Since there are multiple rows of sensor elements at different positions on the y-axis to receive light from the light source 530, such an arrangement may allow for greater flexibility on the y-axis.

[0047] Figure 9 is a graph of corneal displacement over time. Corneal displacement is due to compression of the cornea in response to the air puff from the tonometer nozzle. Therefore, the greater the compression, the greater the corneal displacement, as shown in graph 600. Displacement plateaus at the point of corneal applanation. At this point, the cornea may be slightly concave. However, because the incident beam approaches the eye laterally, the measured displacement may not detect instantaneous corneal concavity. 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 preferred accuracy.

[0048] In some embodiments, a processor (e.g., controller 110, Figure 1) is configured to calculate the standoff distance and / or IOP based on eye position and / or corneal displacement measurements obtained by a sensor array (e.g., 132, 232, 323, 432, 532a, 532b). In this regard, since the eye position and / or displacement may be associated with the number of sensor elements of the sensor array illuminated by the light beam, the processor may determine the standoff distance and / or IOP based on the number of sensor elements illuminated by the light beam. In some embodiments, the IOP may be based on known parameters of the air puff, such as pressure.

[0049] A 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 it 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.

[0050] Figure 10 is a schematic diagram of an ophthalmic device (e.g., a tonometer 1000). The tonometer 1000 shown in Figure 10 may, in some embodiments, be similar to the tonometer 100 shown in Figure 1 and the tonometer 100 shown in Figure 2. In this regard, the tonometer 1000 shown in Figure 10 includes a housing 102 and a controller 110. The tonometer 1000 further includes an ultrasonic transducer assembly consisting of an ultrasonic transmitter 1030 and an ultrasonic receiver 1032. For example, the ultrasonic transducer assembly may replace a light source 130 and a sensor array 132. The ultrasonic transmitter 1030 is configured to emit ultrasonic pulses toward the eye along a first axis 1031. The ultrasonic receiver 1032 is configured to detect reflections of ultrasonic pulses from the eye along at least a second axis 1033. The tonometer 1000 also includes a pump 120 and a nozzle 122 configured to generate an air puff or air jet. The air puff moves along axis 125. Axis 125 may be aligned with or substantially aligned with the optical axis of the eye. Furthermore, axis 125 may be orthogonal, perpendicular, or otherwise transverse to one or both of the first axis 131 and / or the second axis 133. In some cases, the nozzle 122 may include a structure that serves as a reference point for determining the standoff distance to the eye. In other cases, another structure (e.g., an optical sensor 136) may be used.

[0051] The tonometer 1000 further includes a drug delivery module 140 configured to deliver or administer a drug to the patient's eye. For example, the drug delivery module 140 may be configured to generate a flow or mist of ophthalmic fluid into the eye as part of a treatment regimen. In some embodiments, drug delivery by the module 140 may be based on IOP measurements obtained by the tonometer 1000. The tonometer 1000 further includes a light sensor 136 distinct from the sensor array 132. In some embodiments, the light sensor 136 may be configured for proximity measurement. For example, the light sensor 136 may be configured to determine whether the eye is within a preferred range of the nozzle 122. In some embodiments, the light sensor 136 may be controlled by a controller 110 to determine whether a user who operates the components of the tonometer 1000 is present in the tonometer. In some embodiments, the light sensor 136 may be used for blink detection. In this regard, the controller 110 may be configured to detect blinking based on optical measurements from the light sensor 136 and to activate the pump 120 and / or nozzle 122 after detecting a blink. In some embodiments, the pump 120 may include a valve, and the controller 110 may be configured to activate the valve to release an air puff. In other embodiments, the controller 110 may use an ultrasonic transducer assembly to detect blinking. For example, the controller 110 may detect a momentary increase in the corneal profile based on a signal from the ultrasonic receiver 1032 and determine that a blink has occurred.

[0052] The controller 110 can measure the time of flight based on the difference between a first time corresponding to the emission of an ultrasonic pulse from the ultrasonic transmitter 1030 and a second time corresponding to the detection of a reflection caused by the ultrasonic pulse by the ultrasonic receiver 1032. The controller 110 can then determine the standoff distance to the eye based on the time of flight. For example, the standoff distance may be a measurement between the eye and a structure acting as a reference point (e.g., nozzle 122). In some cases, the measurement can be performed when the eye is within a range determined by the optical sensor 136.

[0053] The tonometer 1000 includes a controller 110 and a memory 112 that communicates with the controller 110. The memory 112 may store instructions that can be executed by the memory 112 to perform one or more of the functions described above. In some embodiments, the memory 112 may further store standoff distance (e.g., eye position), IOP measurements, patient-related data, and / or any other preferred type of information. In some embodiments, the memory 112 may store treatment-related data for generating treatment alerts or indicators for the patient. For example, the memory 112 may store general and / or patient-specific IOP thresholds for determining whether to output an alert to the user or network, or whether to allow the drug delivery module 140 to deliver a drug to the patient's eye.

[0054] Figure 11 is a perspective view of an ultrasonic measurement subsystem 1040 of an ophthalmic device (e.g., a tonometer 1000) according to at least one embodiment of the present disclosure. The subsystem 1040 includes a reference point (e.g., a nozzle 122) and a structure comprising a pair of ultrasonic transducers (e.g., one as a receiver and one as a transmitter), such as an ultrasonic transmitter 1030 and an ultrasonic receiver 1032. The subsystem 1100 determines the position of the eye using time of flight, as described herein.

[0055] The transducers of the assembly, for example, the ultrasonic transmitter 1030 and the ultrasonic receiver 1032, may be side by side. In some implementations, the ultrasonic transmitter 1030 and the ultrasonic receiver 1032 may be angled inward relative to each other along different axes toward the eye (e.g., axes intersecting at the eye). For example, the transducers may each be angled inward at an angle based on the minimum distance required for the ultrasonic receiver 1032 to capture the reflected signal from the ultrasonic transmitter 1030. Angling inward may allow for a narrower field of view. In some implementations, the ultrasonic transmitter 1030 and the ultrasonic receiver 1032 may be coupled to a first housing portion 101 shown in Figure 3. In some embodiments, connector elements 107, 109 shown in Figure 3 are adjustable to adjust the position of the structure, the ultrasonic transmitter 1030, and / or the ultrasonic receiver 1032. For example, in some embodiments, the connector elements 107, 109 may include expandable / contractible features, sliding clamps, rack and pinion mechanisms, hinges, and / or any other suitable adjustment mechanisms.

[0056] 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 pneumatic characteristics. Ultrasonic transmitter 1030 is configured to generate an ultrasonic pulse 1044 (e.g., a frequency of several hundred kHz) along an axis toward the eye. In some embodiments, it will be understood that the ultrasonic pulse 1044 does not have to be precisely perpendicular to axis 125. For example, the beam 1044 may be centered along an axis or direction that is 75° to 105° with respect to axis 125. The ultrasonic pulse 1044 strikes the eye 10 and causes a reflection 1046. Ultrasonic receiver 1032 detects the reflection 1046 within a narrow field of view that includes the eye 10 and excludes other features of the object near the eye 10, such as the nose and forehead of the object. Based on the short distance (e.g., less than 2 inches) between the eye and subsystem 1040, the refresh rate from the ultrasonic receiver 1032 can be high without undesirable aliasing. In some implementations, the ultrasonic transmitter 1030 and ultrasonic receiver 1032 may resonate at 400 kHz and be designed to impedance match to air.

[0057] The ultrasonic transmitter 1030 may be configured to provide a signal indicating that it has emitted an ultrasonic pulse 1044, and the ultrasonic receiver 1032 may be configured to provide another signal indicating a voltage and / or current corresponding to the detection of a reflection 1046. In some embodiments, the ultrasonic receiver 1032 may be configured to provide a signal indicating a binary value indicating whether the ultrasonic receiver 1032 has received a reflection 1046 above a threshold amount. This may allow the ultrasonic receiver 1032 to distinguish the reflection 1046 from echoes and other noise that may be filtered out and ignored. The first signal provided by the ultrasonic transmitter 1030 may indicate a first time corresponding to the emission of the ultrasonic pulse 1044. The second signal provided by the ultrasonic receiver 1032 may indicate a second time corresponding to the detection of the reflection 1046. The controller 110 can measure the time of flight to the eye based on the difference between the first time and the second time. The controller 110 can then determine the standoff distance to the eye with a high resolution, for example, less than 1 mm, based on the time of flight and known values ​​of the speed of the ultrasonic pulse and its reflection in the air. For example, the standoff distance may represent the distance between the eye and a structure containing a reference point (e.g., nozzle 122). Thus, the distance between the eye and the transmitter can be determined by measuring the time difference between pulses transmitted and received on different axes.

[0058] In some implementations, subsystem 1040 may include a focused transducer array (e.g., multiple ultrasonic transmitters and ultrasonic receivers) based on sensitivity and / or range requirements. In some implementations, time-of-flight measurement may be performed with a single transducer using appropriate electrical switching between transmit and receive modes by controller 110. For example, controller 110 may control a transducer (e.g., ultrasonic transmitter 1030) to emit an ultrasonic pulse 1044 in a first time, and then switch the transducer to act as an ultrasonic receiver (e.g., ultrasonic receiver 1032) to detect a reflection 1046 in a second time. In some implementations, to allow the transducer to ring down as quickly as possible, the back of the transducer may be covered with an absorbent layer 1034 which may contain an absorbent material such as epoxy impregnated with tungsten powder. This allows the transmit pulse to be relatively short and attenuated before the echo arrives from a nearby object.

[0059] Figure 12 is a front view of an ultrasonic measurement subsystem 1100 according to at least one embodiment of the present disclosure. Similar to subsystem 1040 shown in Figure 11, subsystem 1100 includes a structure comprising a reference point (e.g., nozzle 122) for determining the standoff distance to the eye. Subsystem 1040 also includes a pair of ultrasonic transducers (e.g., one as a receiver and one as a transmitter), such as ultrasonic transmitter 1130 and ultrasonic receiver 1132. Subsystem 1100 determines the position of the eye using time of flight, as described herein.

[0060] The transducers of the assembly, for example, the ultrasonic transmitter 1130 and the ultrasonic receiver 1132, may be arranged concentrically, for example, with respect to each other, along an axis toward the eye (e.g., an axis intersecting at the eye). In some implementations, the ultrasonic transmitter 1130 and the ultrasonic receiver 1132 may be coupled to a first housing portion 101 shown in Figure 3. In some embodiments, the connector elements 107, 109 shown in Figure 3 are adjustable to adjust the position of the structure, the ultrasonic transmitter 1130, and / or the ultrasonic receiver 1132. For example, in some embodiments, the connector elements 107, 109 may include telescopic features, sliding clamps, rack and pinion mechanisms, hinges, and / or any other suitable adjustment mechanisms.

[0061] As similarly described above with respect to Figure 11, the ultrasonic transmitter 1130 is configured to generate ultrasonic pulses (e.g., with a frequency of several hundred kHz) along an axis toward the eye. In some embodiments, it will be understood that the ultrasonic pulses do not have to be precisely perpendicular to axis 125. For example, the beam 1044 may be centered along an axis or direction that is 75° to 105° with respect to axis 125. The ultrasonic pulses strike the eye 10 and cause a reflection. The ultrasonic receiver 1132, concentric with the ultrasonic transmitter 1130, can detect the reflection 1046 along the same axis from which the ultrasonic transmitter 1130 emitted the pulse. This can allow for a narrow field of view that includes the eye 10 and excludes other features of the object near the eye 10, such as the nose and forehead. Based on the short distance between the eye and subsystem 1140 (e.g., less than 2 inches), the refresh rate from the ultrasonic receiver 1032 can be high without undesirable aliasing. In some implementations, the ultrasonic transmitter 1130 and ultrasonic receiver 1132 may resonate at 400 kHz and be designed to be impedance-matched to air.

[0062] The ultrasonic transmitter 1130 may be configured to provide a signal indicating the emission of an ultrasonic pulse, and the ultrasonic receiver 1132 may be configured to provide another signal indicating a voltage and / or current corresponding to the detection of a reflection. In some embodiments, the ultrasonic receiver 1132 may be configured to provide a signal indicating a binary value indicating whether the ultrasonic receiver 1132 has received a reflection exceeding a threshold amount. This may enable the ultrasonic receiver 1132 to distinguish reflections from echoes and other noise that might be filtered out and ignored. The first signal provided by the ultrasonic transmitter 1130 may indicate a first time corresponding to the emission of an ultrasonic pulse. The second signal provided by the ultrasonic receiver 1132 may indicate a second time corresponding to the detection of a reflection. The controller 110 can measure the time of flight to the eye based on the difference between the first time and the second time. The controller 110 can then determine the standoff distance to the eye with high resolution, for example, less than 1 mm, based on the time of flight and known values ​​of the speed of the ultrasonic pulse and its reflection in the air. For example, the standoff distance may represent the distance between the eye and a structure containing a reference point (e.g., nozzle 122). Therefore, the distance between the eye and the transmitter can be determined by measuring the time difference between a transmitted pulse and a received pulse on the same axis.

[0063] Communication with ophthalmic equipment (e.g., tonometer 100) (including, but not limited to, software updates, firmware updates, or readings from the device) can be achieved using any suitable wireless or wired communication technology, such as cable interfaces like USB, micro USB, Lightning, or FireWire interfaces, or cellular data connections like Bluetooth, Wi-Fi, ZigBee, Li-Fi, or 2G / GSM, 3G / UMTS, 4G / LTE / WiMax, or 5G. For example, Bluetooth Low Energy (BLE) wireless can be used to establish connectivity with cloud services for data transmission and software patch reception. 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 may include a non-contact tonometer, such as a handheld non-contact tonometer. Standoff distance and / or IOP measurements can be taken using the tonometer and communicated from the tonometer using the described wireless or wired communication capabilities.

[0064] The logical operations constituting embodiments of the technology described herein may be referred to in various ways as operations, configurations, objects, elements, components, or modules. It should be understood that these may be performed or arranged in any order unless expressly otherwise requested, or unless a particular order is essentially required by the language of the claims.

[0065] For example, references to all directions, such as up, down, inward, outward, upward, downward, left, right, sideways, front, back, upper, bottom, superior, downward, vertical, horizontal, clockwise, counterclockwise, proximal, and distal, are used solely for identification purposes to aid the reader's understanding of the claimed subject matter and do not impose any limitations, particularly with respect to the position, orientation, or use of the jet pump for non-contact intraocular tonometry. References to connections, such as mounted, coupled, connected, and joined, should be interpreted broadly and, unless otherwise indicated, may include intermediate members between sets of elements and relative movement between elements. Thus, references to connections do not necessarily mean that two elements are directly connected and in a fixed relationship with one another. The term "or" shall be interpreted as "and / or" and not "exclusive OR." Unless otherwise stated in the claims, the values ​​stated should be interpreted as illustrative only and not restrictive.

[0066] 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 degree of specificity or by reference to one or more individual embodiments, those skilled in the art can make numerous modifications to the disclosed embodiments without departing from the spirit or scope of the claimed subject matter. For example, the jet pump can be used to generate a controlled puff of gas other than ambient air, including but not limited to oxygen, nitrogen, helium, and argon, or of gas containing colorants, odorants, pharmaceuticals, or other materials. In addition, some or all components of the jet pump may be housed in a housing, either alone or together with other components such as a battery and / or power supply.

[0067] Further embodiments are contemplated. All matters included in the above specification and shown in the accompanying drawings are intended to be interpreted not as limiting but as illustrative examples of specific embodiments. Modifications of detail or structure may be made without departing from the basic elements of the subject matter as defined in the following claims. Those skilled in the art will recognize that the devices, systems, and methods described above can be modified in various ways not expressly described or suggested above. Accordingly, those skilled in the art will understand that the embodiments contained herein are not limited to the specific exemplary embodiments described above. In this regard, while illustrative embodiments have been shown and described, a wide range of modifications, changes, and substitutions are contemplated in the above disclosure. It is understood that such modifications may be made to those described herein without departing from the scope of the above disclosure. Accordingly, it is appropriate that the accompanying claims be interpreted broadly and, in some sense, in accordance with the present disclosure.

[0068] Some implementations may include a system comprising: a structure disposed along a first axis toward the eye; a linear sensor array disposed distal to the structure; a light source oriented to emit a light beam toward the linear sensor array along a second axis, the light beam having a width toward the eye such that a first portion of the light beam illuminates the outer surface of the eye and a second portion of the light beam passes in front of the eye; and a processor, the processor configured to execute instructions stored in memory to determine the standoff distance between the structure and the eye along the first axis based on measurements of the second portion of the light beam via the linear sensor array. In some implementations, the structure comprises a pump configured to generate a puff of air and a nozzle communicating with the pump, the standoff distance being between the nozzle and the eye. In some implementations, the light source comprises an optical element and a collimating lens configured to collimate the light beam along at least one axis. In some implementations, the system may further include a collimating lens coupled to the linear sensor array, configured to linearly focus the light beam toward the linear sensor array. In some implementations, the collimating lens is positioned adjacent to the linear sensor array. In some implementations, the system may include a second linear sensor array positioned adjacent to the linear sensor array, and both the second and linear sensor arrays are oriented toward a third axis toward the light source. In some implementations, the third axis is parallel to the second axis. In some implementations, the processor is further configured to receive a plurality of displacement measurements from the linear sensor array over a period of time and execute a memory-stored instruction to determine the eye's IOP based on the plurality of displacement measurements and the period. In some implementations, the linear sensor array comprises a one-dimensional array of photodiodes. In some implementations, the linear sensor array comprises a two-dimensional array of photodiodes. In some implementations, the light source is configured to emit light in the visible light spectrum. In some implementations, the light source comprises an optical element and a cylindrical lens or Powell lens configured to magnify the light beam.In some implementations, the system may include a rod lens or cylindrical lens configured to focus a light beam onto a linear sensor array.

[0069] Some implementations may include a system comprising: a structure disposed along a first axis toward the eye; an ultrasonic transducer assembly oriented to emit ultrasonic pulses toward the eye and to detect reflections of ultrasonic pulses from the eye, wherein the ultrasonic transducer assembly is configured to emit ultrasonic pulses and detect reflections within a field of view including the eye and excluding the nose and forehead near the eye; and a processor, wherein the processor is configured to execute instructions stored in memory to measure time of flight based on the difference between a first time corresponding to emitting ultrasonic pulses and a second time corresponding to detecting reflections, and to determine the standoff distance between the structure along the first axis and the eye based on the time of flight. In some implementations, the ultrasonic transducer assembly comprises a transmitter configured to emit ultrasonic pulses and a receiver configured to detect reflections. In some implementations, the transmitter and receiver are angled inward with respect to each other along the axis toward the eye. In some implementations, the transmitter and receiver are arranged concentrically with respect to each other along the first axis toward the eye. In some implementations, the ultrasonic transducer assembly comprises a transceiver that switches between a transmit mode, which emits ultrasonic pulses, and a receive mode, which detects reflections. In some implementations, the system may include an absorbing layer disposed on the surface of the ultrasonic transducer assembly, the absorbing layer being configured to absorb echoes of the ultrasonic pulses. In some implementations, the ultrasonic transducer assembly includes a transducer configured to resonate at a frequency of at least 400 kHz.

[0070] It will be apparent to those skilled in the art that, when utilizing various aspects of the embodiments, combinations or modifications of the above embodiments are possible to form a fan-out system in a package including multiple redistribution layers. While the embodiments have been described in language specific to structural features and / or methodological behavior, it should be understood that the appended claims are not necessarily limited to the specific features or behaviors described. The specific features and behaviors disclosed should rather be understood as illustrative embodiments of the claims.

Claims

1. It is a system, A structure arranged along the first axis toward the eye, A linear sensor array is disposed distal to the aforementioned structure, A light source oriented to emit a light beam toward the linear sensor array along a second axis, wherein the light beam has a width toward the eye, so that a first portion of the light beam illuminates the outer surface of the eye and a second portion of the light beam passes in front of the eye. A processor and a processor, the processor A system configured to execute a memory-stored instruction to determine the standoff distance between the structure and the eye along the first axis, based on a measurement of the second portion of the light beam via the linear sensor array.

2. The system according to claim 1, wherein the structure comprises a pump configured to generate a puff of air and a nozzle communicating with the pump.

3. The system according to 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 according to claim 1, further comprising a collimating lens coupled to the linear sensor array, wherein the collimating lens is configured to linearly focus the light beam toward the linear sensor array.

5. The system according to claim 4, wherein the collimating lens is disposed adjacent to the linear sensor array.

6. The system according to claim 1, further comprising a second linear sensor array disposed adjacent to the linear sensor array, wherein the second linear sensor array and the linear sensor array are oriented along a third axis toward the light source.

7. The system according to claim 6, wherein the third axis is parallel to the second axis.

8. The aforementioned processor, Multiple displacement measurements obtained over a certain period of time are received from the linear sensor array. The system according to claim 1, further configured to execute instructions stored in memory for determining the intraocular pressure (IOP) of the eye based on the plurality of displacement measurements and the period.

9. The system according to claim 1, wherein the linear sensor array comprises a one-dimensional array of photodiodes.

10. The system according to claim 1, wherein the linear sensor array comprises a two-dimensional array of photodiodes.

11. The system according to claim 1, wherein the light source is configured to emit light in the visible light spectrum.

12. The system according to claim 1, wherein the light source comprises an optical element and a cylindrical lens or Powell lens configured to magnify the light beam.

13. The system according to claim 1, further comprising a rod lens or cylindrical lens configured to focus the light beam onto the linear sensor array.

14. It is a system, A structure arranged along the first axis toward the eye, An ultrasonic transducer assembly oriented to emit ultrasonic pulses toward the eye and to detect the reflection of the ultrasonic pulses from the eye, wherein the ultrasonic transducer assembly is configured to emit ultrasonic pulses and detect the reflection within a field of view that includes the eye and excludes the nose and forehead near the eye, A processor and a processor, the processor The flight time is measured based on the difference between a first time corresponding to the emission of the ultrasonic pulse and a second time corresponding to the detection of the reflection. A system configured to execute instructions stored in memory, which determine the standoff distance between the structure and the eye along the first axis based on the flight time.

15. The system according to claim 14, wherein the ultrasonic transducer assembly comprises a transmitter configured to emit the ultrasonic pulses and a receiver configured to detect the reflections.

16. The system according to claim 15, wherein the transmitter and the receiver are angled inward relative to each other along the axis toward the eye.

17. The system according to claim 15, wherein the transmitter and the receiver are arranged concentrically with respect to each other along a first axis toward the eye.

18. The system according to claim 14, wherein the ultrasonic transducer assembly includes a transceiver that switches between a transmission mode for emitting ultrasonic pulses and a reception mode for detecting reflections.

19. The system according to claim 14, further comprising an absorption layer disposed on the surface of the ultrasonic transducer assembly, wherein the absorption layer is configured to absorb echoes of the ultrasonic pulses.

20. The system according to claim 14, wherein the ultrasonic transducer assembly includes a transducer configured to resonate at a frequency of at least 400 kHz.

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