Ophthalmic device, method, and memory with self-alignment for operatorless operation

Abstract

The object is to easily position the device relative to the user's eyes. [Solution] A processor sends a signal to a display to indicate a target. An optical system is positioned in the optical path taken by the target from the display to the user's eye as indicated by the display. The optical system has an adjustable focal length configured to vary accommodation by the eye, allowing the user to view the target with varying visual acuity. The processor then obtains an indication that the user's eye is focused on the target. In response, the processor sends a signal to an alignment mechanism to align a sensor in the device with the user's eye. After signaling the alignment mechanism to align the sensor with the user's eye, the processor obtains sensor data generated by the sensor measuring characteristics of the eye. Other aspects are also described and claimed.

Description

Technical Field

[0001] This patent application claims the benefit of the earlier filing date of U.S. Patent Provisional Application No. 63 / 376,187, filed on September 19, 2022.

[0002] The subject matter of the present disclosure relates to an ophthalmic device for measuring the characteristics of a user's eye.

Background Art

[0003] There are several eye devices for measuring the characteristics of a user's eye, such as intraocular pressure, the state of the retina, and the topography of the cornea. These devices may require alignment between the device and the user's eye. Conventionally, alignment has been achieved based on input from a human operator, such as a doctor, doctor's assistant, or nurse, who views the user's eye while the user's head is resting on a chin / headrest, and the operator manually moves the device to its proper position.

Summary of the Invention

[0004] It would be desirable to have an eye device that can be positioned relative to a user's eye and that can perform measurements of the user's eye without any assistance from an operator. This would reduce costs and enable measurements to be taken outside of a doctor's office. One aspect of the present disclosure is an eye device that presents a visual alignment target that the user is instructed to look at. The user can move their eye close to the device and then be instructed to look through the device's viewport for the target. The target can be either a still image or a moving image presented by a display, such as a microdisplay within the device. An alignment mechanism within the device automatically aligns an eye characteristic measurement sensor with the eye in order to ensure the accuracy of the measurement. The alignment is automatic in that it does not require input from an operator.

[0005] Alignment sometimes requires that the user can see the target with sufficient visual acuity. However, in many eye measurements, users cannot wear glasses or contact lenses during the measurement, and because of the wide distribution of myopia and hyperopia in the population, it is difficult for all users to see the target with sufficiently high resolution (necessary to ensure comfortable and timely alignment). In addition, as users age, there are changes in their range of accommodation (the distance between the eye and the target for comfortable viewing), and therefore this also reduces the population that can see the target well enough.

[0006] According to one aspect of the disclosure herein, a device for measuring eye characteristics comprises a device housing (e.g., a desktop or handheld device housing) containing a sensor subsystem (sensor) for measuring the characteristics of the user's eye. An electronically controlled alignment mechanism coupled to the sensor aligns the sensor to the user's eye. The device housing also includes a display that indicates a target to the user's eye and an optical system positioned in the optical path taken by the target (as indicated by the display) from the display to the user's eye. The optical system has an adjustable focal length configured to change the accommodation by the eye, allowing the user to view the target with varying visual acuity. The alignment process performed by the alignment mechanism is triggered (to start or restart) in response to the processor obtaining an indication that the user's eye is in focus on the target (or that the user can view the target with sufficient visual acuity). Thus, the alignment that prepares the sensor for measuring eye characteristics is likely to be faster and more accurate, making the eye examination process more efficient.

[0007] The above summary does not constitute an exhaustive list of all aspects of the Disclosure. The Disclosure is intended to include all systems and methods that can be implemented from all appropriate combinations of the various aspects 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 advantages not specifically described in the above summary. [Brief explanation of the drawing]

[0008] Some aspects of the disclosure herein are shown in the accompanying drawings as examples, not limitations. In the drawings, 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. Also, for brevity and to reduce the total number of drawings, a given drawing could be used to illustrate features of two or more aspects of this disclosure, and not all elements in the drawing are required for a given aspect.

[0009] [Figure 1] This image shows an exemplary ophthalmic device being held by the user in their hand while the device performs ophthalmic measurements on the user's eye. [Figure 2] This block diagram shows specific components of an exemplary ophthalmic device that enables intraocular pressure (IOP) measurement. [Figure 3] This block diagram shows specific components of an exemplary ophthalmic device in Figure 1 that enable retinal imaging or corneal topography mapping. [Figure 4] This is a flowchart illustrating the process performed by a programmed processor to measure eye characteristics using an ophthalmic device. [Modes for carrying out the invention]

[0010] Next, several aspects of this disclosure will be described with reference to the accompanying drawings. Wherever the shape, relative position and other aspects of the described parts are not expressly defined, the scope of the invention is not limited to the parts shown merely as examples. Also, although many details are described, it will be understood that some aspects of the disclosure can be carried out without these details. In other examples, well-known circuits, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0011] Figure 1 shows an exemplary device 2 being held by a user in their hand relative to their eye while the device performs ophthalmic measurements on the user's eye. Although device 2 is shown as a handheld device (the user holds the device housing in their hand), one alternative configuration is a desktop device in which the device housing (of device 2) is either built-in or mounted on a stand, the stand being a desktop device that can be placed on a table, for example, while the user moves their eye closer to device 2. Proximity is the distance between the device housing and the eye, which can be used by sensor 3 to measure eye characteristics. The eye characteristics to be measured may be intraocular pressure (IOP), or a side of the cornea or retina (for example, as depicted in the form of a digital image or map).

[0012] Referring now to Figure 2, this is a block diagram showing some components of an example of device 2, including sensor 3 within the device housing. In one embodiment, sensor 3 may include a receiving element (e.g., a photodetector, a pixel array) and a transmitting element (e.g., a photoemitter), and any relevant optical components (e.g., filters, lenses) that can be used to measure IOP. In this case, sensor 3 may be an optical sensor that is part of an air puff tonometer, where sensor 3 is directed to a specific area on the corneal surface, while an air puff generator mechanism within device 2 flattens that area. Sensor 3 takes a measurement of the flattened area of ​​the cornea, and the measurement is then digitally processed to yield an IOP value. In another embodiment, sensor 3 is part of an intraocular pressure monitoring subsystem having an intraocular pressure measuring device. Here, sensor 3 may be an optical receiver or transceiver that needs to be aligned with the implanted measuring device to generate an IOP value.

[0013] Sensor 3 may need to be aligned with the eye in order to generate eye characteristic measurements. Therefore, sensor 3 is coupled to an alignment mechanism 4 (also located within the device housing). The alignment mechanism 4 is electronically controlled by a processor 6 and may include actuators that move sensor 3 in response to commands from the processor 6, in other words, that actuate any movable components of sensor 3 (e.g., the emitter, detector, or optical components of sensor 3).

[0014] The processor 6 is configured or programmed to signal the alignment mechanism 4 (for example, when executing instructions stored in memory (not shown)) to start or restart either an open-loop or closed-loop process to align the sensor 3 to the user's eye. In one aspect of the disclosure herein, the processor 6 may do so only in response to some indication that the user's eye is in focus on a target displayed on the display 7, in other words, the user can see the target with sufficient visual acuity. This helps ensure that the alignment process accurately and quickly positions the sensor 3 to measure eye characteristics. The target may be a graphical object or an image of a real object shown by the display 7 within the device housing. The display 7 may be a microdisplay, for example, a small display having a diagonal display size of less than 2 inches. The target may be a still image or an active image displayed by the display 7. State information may also be presented by the display 7, for example, a countdown clock, which eye is being measured, etc. The optical system 8 within the device housing is positioned in the optical path taken by the target (as the target is shown by the display 7). The optical path, as shown in the diagram, is from display 7 to the user's eye.

[0015] The optical system 8 is configured to alter the accommodation of the eye and has an adjustable focal length that allows the user to view the target with varying visual acuity. By altering accommodation, the user can view the target more easily, particularly when the display 7 is positioned 200 millimeters or less from the eye (when the device housing is close to the eye). In one embodiment, the optical system 8 includes a convex solid lens that is motorized to be electronically controlled and movable by the processor 6. This is a general description, of course, to include cases where the optical system 8 includes a set of two or more lenses (e.g., a convex lens and a concave lens) and one or more lenses whose axial position can be electronically adjusted and controlled by the processor 6. The axial position can be adjusted by making the lens axially movable, or similarly by making the display 7 axially movable. In another embodiment, the optical system 8 includes a fluid lens whose shape is electronically controlled by the processor 6 (to change the focal length).

[0016] In one embodiment, the processor 6 is configured to obtain an indication that the user's eyes are focused on the target by prompting the user to indicate when the user can clearly see the target while the processor 6 is signaling the optical system 8 to change its focal length. This prompting may be performed by the processor 6 signaling an audio subsystem (not shown) to the user, instructing them to "press the button or respond verbally when you can clearly see the target." The audio subsystem may have a microphone within the device housing, and the processor 6 processes the audio signal output by the microphone to detect audible input from the user as an indication that the user can clearly see the target.

[0017] Alternatively, the focal length of the optical system 8 may be manually adjustable by the user, for example, by turning a knob inside the device housing. In this case, the processor 6 may be configured to obtain an indication that the user's eyes are focused on the target by receiving manual (e.g., button press) or audible input from the user so that the user can clearly see the target. For example, the user may be instructed to manually adjust the optical system 8 with their fingers until they can clearly see the target, at which point the user presses a button or speaks a phrase that the processor 6 interprets as indicating that the user can clearly see the target.

[0018] In another embodiment, device 2 includes an eye-tracking subsystem within the device housing. In this case, processor 6 is configured to process eye-tracking data generated by the eye-tracking subsystem to determine whether the eyes are looking at a target shown on display 7, and in response, the processor signals alignment mechanism 4 to perform an alignment process.

[0019] In another embodiment, referring here to Figure 3, in addition to sensor 3, an imager / scanner 9, which can be used to map the retina or cornea of ​​the eye, is located within the device housing. The imager / scanner 9 may include an imaging sensor as part of a still camera or video camera, a laser scanner, or both, along with their associated optical systems. The imager / scanner 9 is positioned to receive light reflected from the eye from the back of the beam splitter. In contrast, the front of the beam splitter plays the role of reflecting light generated by the display 7 towards the eye so that the user can see the target. The beam splitter enables device 2 to perform different eye characteristic measurements. The beam splitter enables the imager / scanner 9 to capture a digital image of the retina or corneal surface of the eye (the image may then be digitally processed before being displayed to the user as a retinal photograph or corneal topography map), allowing the user to focus on the target in the display 7 during the automatic alignment of sensor 3 (which is measuring other eye characteristics, e.g., IOP).

[0020] Referring now to Figure 4, this figure is a flowchart of the method performed by the processor 6 and other components of device 2 to measure the characteristics of the user's eye using device 2. The method can begin with operation 11, in which the processor signals the display 7 to indicate a target. The user can then see the target through the viewport of the device housing when the user's eye is positioned close to device 2 and looking in the direction of the display 7. The coarsest level of alignment may be when the user can see the display 7 but is not in focus on the target indicated on the display 7. A finer level of alignment is desirable, which is when the user can clearly see the target (or is said to be "in focus" on the target). Thus, in operation 13, the processor 6 obtains an indication that the user's eye is in focus on the target. Then, in operation 14, it responds by sending a signal to the alignment mechanism 4 to align sensor 3 to the user's eye. Next, the alignment process is performed as operation 15 (for example, the alignment mechanism 4 adjusts the position of sensor 3), and then, once sensor 3 and the eye are deemed aligned, processor 6 acquires sensor data generated by sensor 3, measuring some characteristic of the eye (e.g., IOP measurement) in operation 17. If device 2 is equipped with an imager / scanner 9 as shown in Figure 3, other eye characteristic measurements, such as taking a retinal photograph or generating a corneal topography map, can also be triggered here. Next, processor 6 can prepare appropriate eye characteristic measurement data from the sensor output data for storage or display to the operator (operation 19).

[0021] In one embodiment of the method shown in Figure 4, operation 13, which involves determining when the user's eyes are in focus on the target, includes operation 18. In operation 18, the processor 6 prompts the user to indicate when the user can clearly see the target. If the optical system 8 is electronically controllable, this may occur while the processor signals the optical system 8 to change its focal length, or the user is turning a manual focus knob (operation 19). The prompt may be an audio command output by the audio subsystem of device 2 that the user can hear. The user's response to the prompt is evaluated in operation 20, and the user's response may be in an audible form, such as a phrase spoken by the user. The phrase may be recognized by the processor 6 processing an audio signal output by the microphone of the audio subsystem (e.g., "I can now clearly see the target"). If it is determined in operation 20 that the target is not in focus, the method repeats operation 19 by waiting for the user to turn the focus knob, or by the processor signaling the optical system to adjust its focal length.

[0022] Instead of the processor 6 sending a signal to the motorized actuator or fluid lens of the optical system 8 to change the focal length, the optical system 8 may have a manually adjustable focal length, for example, a focus knob adjustable by the user's finger. User indication that the target is in focus may be a manual input, such as a button pressed by the user.

[0023] In another embodiment of the method shown in Figure 4, the processor 6 processes the eye-tracking data generated by the eye-tracking subsystem in the device 2 to determine whether the user's eyes are looking at the target, and in response, the processor signals the alignment mechanism to perform the alignment process.

[0024] While certain embodiments are described and shown in the accompanying drawings, these are merely illustrative and not limiting of the invention, and it will be understood by those skilled in the art that the present invention is not limited to the specific structures and arrangements shown and described, as various other modifications may be made. For example, the processor 6 (together with the sensor 3, display 7, alignment mechanism 4, and optical system 8) may be integrated within the device housing, but in some cases, some of the functions or operations performed by the processor 6 may be performed by another processor that communicates with the processor in the device housing via wired or wireless communication. The other processor may be a processor in a notebook computer, tablet computer, smartphone, or website server. Therefore, this description should be considered illustrative rather than limiting.

Claims

1. A device for measuring the characteristics of the eye, Device housing and A sensor within the device housing for measuring the characteristics of the user's eyes, The electronically controlled alignment mechanism to which the aforementioned sensor is coupled, A display within the device housing that indicates the target, An optical system located within the device housing and positioned in the optical path taken by the target from the display to the user's eye, as shown by the display, wherein the optical system is configured to change the accommodation by the eye and has an adjustable focal length that allows the user to view the target with changing visual acuity; A processor configured to send a signal to the electronically controlled alignment mechanism to move the sensor to a position aligned with the optical axis of the user's eye in response to obtaining an indication that the user's eye is focused on the target, A device equipped with the following features.

2. The device according to claim 1, wherein the device housing is the housing of a handheld device held in the user's hand while the user brings the device close to the user's eye, the proximity being the distance between the device housing and the eye, such that the sensor can measure the pressure of the eye or take an image while the user's eye can see the target indicated by the display.

3. The device according to claim 1, wherein the target is a still image or an active image.

4. The device according to claim 2, wherein the display is positioned within 200 millimeters of the eye when the device housing is in close proximity to the eye.

5. The device according to claim 4, wherein the optical system includes a movable convex solid lens.

6. The device according to claim 5, wherein the convex solid lens is motorized so as to be electronically controlled and movable by the processor.

7. The device according to claim 4, wherein the optical system includes a fluid lens whose shape is electronically controlled by the processor.

8. The aforementioned processor, The device according to claim 6, configured to obtain the indication that the user's eyes are in focus on the target by prompting the user to indicate when the user can clearly see the target while the processor is signaling the optical system to change the adjustable focal length.

9. The device according to claim 8, further comprising a microphone within the device housing, wherein the processor processes an audio signal output by the microphone to detect an audible input from the user as an indication that the user can clearly see the target.

10. The aforementioned processor, The device according to claim 1, wherein the device is configured to obtain the indication that the user's eyes are in focus on the target by receiving manual or audible input from the user that the user can clearly see the target, and the optical system can be manually adjusted by the user until the user can clearly see the target.

11. The device according to any one of claims 1 to 10, further comprising an eye-tracking subsystem within the device housing for tracking the user's eyes, wherein the processor is configured to process eye-tracking data generated by the eye-tracking subsystem to determine whether the user is looking at the target, and in response to this, send a signal to the electronically controlled alignment mechanism.

12. A method for measuring the characteristics of an eye using a device, wherein the method is performed by a programmed processor. Sending a signal to indicate a target on a display within the device, wherein the device comprises an optical system positioned in the optical path taken by the target, from the display to the user's eye, as indicated by the display, the optical system being configured to change the accommodation by the eye and having an adjustable focal length that allows the user to view the target with changing visual acuity, and sending a signal to indicate a target on a display within the device. The device obtains an indication that the user's eye is focused on the target, and in response sends a signal to the alignment mechanism within the device to move the sensor within the device to a position aligned with the optical axis of the user's eye. After sending a signal to the alignment mechanism to move the sensor, the characteristics of the eye are measured, and sensor data generated by the sensor is acquired. A method that includes the action of [this action].

13. Obtaining the indication that the user's eye is focused on the target means that the programmed processor The method of claim 12, comprising prompting the user to indicate when the user can clearly see the target while a signal is being sent to the optical system to change the adjustable focal length.

14. Obtaining an indication that the user's eye is focused on the target means that the programmed processor, The method according to claim 13, comprising processing an audio signal output by a microphone in the device in order to detect an audible input from the user as an indication that the user can clearly see the target.

15. Obtaining the indication that the user's eye is focused on the target means that the programmed processor The method according to claim 12, comprising receiving manual or audible input from the user that the user can clearly see the target after the user has manually adjusted the optical system until the user can clearly see the target.

16. The programmed processor, The method according to any one of claims 12 to 15, further comprising processing eye-tracking data generated by an eye-tracking subsystem in the device that tracks the user's eyes to determine whether the user is looking at the target, and in response to the determination that the user is looking at the target, a signal is sent to the alignment mechanism in the device to align the sensor.

17. The method according to claim 12, wherein the target is a still image or an active image.

18. The method according to claim 17, wherein the device comprises a device housing, and the display is positioned within 200 millimeters of the eye when the device housing is close to the eye.

19. A memory that stores instructions internally, wherein the instructions are methods, Sending a signal to indicate a target on a display within a device, wherein the device comprises an optical system positioned in the optical path taken by the target, from the display to the user's eye, as indicated by the display, the optical system being configured to change the accommodation by the eye and having an adjustable focal length that allows the user to view the target with changing visual acuity, and sending a signal to indicate a target on a display within the device. The device obtains an indication that the user's eye is focused on the target, and in response sends a signal to the alignment mechanism within the device to move the sensor within the device to a position aligned with the optical axis of the user's eye. After sending a signal to the alignment mechanism to move the sensor, the characteristics of the eye are measured, and sensor data generated by the sensor is acquired. Memory, which is what configures the processor to perform the method.

20. The memory according to claim 19, which internally stores further instructions that configure the processor to process eye-tracking data generated by an eye-tracking subsystem in the device that tracks the user's eyes to determine whether the user is looking at the target, and in response to the processor determining that the user is looking at the target, the processor sends a signal to the alignment mechanism in the device to align the sensor.

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