AUGMENTED REALITY-BASED SYSTEM FOR MEASURING AND TREATING VERGENCE DISORDERS AND METHOD OF USING THE SAME
20210373655 · 2021-12-02
Inventors
Cpc classification
G06F3/011
PHYSICS
A61B3/08
HUMAN NECESSITIES
G02B27/0093
PHYSICS
International classification
Abstract
A system and method for measuring and treating vergence disorders may include an augmented reality headset connected to a computing device for simultaneously presenting target images independently to a patient's eyes and independently tracking the position of each eye. The headset includes eye tracking technology for monitoring the orientation of the eyes. If the eyes are both on target, as determined by the eye tracking technology, then binocular single vision will occur, and if not, then diplopia will occur. A vergence demand may be created by incrementally moving the target images apart or together, until the vergence demand is too great for the patient to maintain SBV. Amplitudes of fusional vergence may be measured and stored by the computing device. The system may be utilized to perform therapeutic vergence treatment exercises to increase amplitudes of fusional vergence and measure and provide treatment for phoria and strabismus conditions.
Claims
1. A system for measuring and treating eye disorders, comprising: a wearable headset configured to be positioned on an eye patient's head and independently display objects to each of a patient's eyes responsive to received signals; eye tracking technology incorporated into the headset and configured to determine, independently, for each eye, the position and direction of gaze of each of a patient's eyes; a computing device connected to the headset by means of a coupling, the computing device comprising firmware configured to cause images of objects to be communicated to each eye, via the coupling, at specific, pre-determined positions for each eye, the computing device further configured to receive, from the eye tracking technology of the headset, eye position and direction of gaze data, and further configured, based on the data and position of the images of objects, a clinical condition of the patients eyes.
2. The system of claim 1, wherein the clinical condition is binocular singular vision.
3. The system of claim 1, wherein the clinical condition is the existence of a strabismus condition.
4. The system of claim 3, wherein the clinical condition is the magnitude of a strabismus condition.
5. The system of claim 1, wherein the clinical condition is the existence of a phoria condition.
6. The system of claim 5, wherein the clinical condition is the magnitude of a phoria condition.
7. The system of claim 1, wherein the position of the objects is varied, over time, by the system, to alter a clinical condition.
8. The system of claim 7, wherein the duration or magnitude of the variance of the position of the objects is determined and varied, by the system, based on the magnitude of a clinical condition determined by the system.
9. A method for the measurement and treatment of eye conditions, comprising the steps of: sending for display on an augmented reality headset, by a computing device, a first target image presented to a left eye of a patient and a second target image presented to a right eye of the patient; determining the orientations and positions of the left eye and the right eye of the patient by eye tracking technology of the headset in response to sending the first and second target images for display on the headset; sending an orientation signal containing orientation information of the left and right eyes of the patient from the headset to the computing device, in response to determining the orientations of the left eye and the right eye of the patient by the eye tracking technology; using the orientation signal, by the computing device, and the known positions of the targets projected by the system, to move the targets relative to each other until BSV is achieved; storing the eye position and target image location information at the point BSV is achieved in the system; while monitoring the eye and target positions in the system, creating a vergence demand by the system by moving the target images relative to each other in a first direction until the system determines, based on the eye and target positions, the point at which fusion is lost (the point being the “amplitude of fusional vergence”; and, storing, in the system the amplitude of fusional vergence, along with the eye and target positions at the amplitude of fusional vergence;
10. The method of claim 9, further comprising the steps of: automatically moving the target images relative to each other by the computing device in a second direction opposite the first direction until BSV (“binocular single vision”) occurs, as detected by the eye tracking technology, wherein each of the left eye and the right eye is directed at its corresponding target image, and storying the time and amplitude of fusion when this occurred; and, automatically iteratively repeating the step of creating a vergence demand and subsequent steps, wherein the vergence demand is increased with each iteration until a predetermined amplitude of fusional vergence is attained.
11. A method for measuring and treating eye disorders comprising the steps of: instructing an augmented reality headset to display an identical object (target) to each eye such that BSV occurs in response to operation of a system for measuring and treating eye disorders; determining by the system an exact position of each of the eyes using an eye tracking technology of the augmented reality headset, which communicates the eye position to the system; Eliminating (blanking) the object (target) for a short period of time for the first eye, so that only the second (unblanked) eye still sees the target; monitoring each eye for movement while the first eye is blanked using the augmented reality headset; determining by the system, based on eye tracking data provided to the system by the augmented reality headset, if either eye moved when the first eye was blanked, and the magnitude of that motion; determining by the system that if the unblanked eye moved to fixate on the presented target, a strabismus condition exists for the unblanked eye, and the system further captures the magnitude of that motion and associates it with the strabismus condition; determining by the system if the blanked eye moved when it was blanked (and the magnitude of that motion), and if it did, that a phoria condition exists for the blanked eye, and further captures the magnitude of that motion and associates it with the phoria condition; and, repeating the steps by the system, but switching the eye that is blanked.
12. The method of claim 11, further comprising the step of repeating the method, for each eye, at a plurality of gaze positions.
13. The method of claim 12, wherein the number of the plurality of gaze positions is at least 3.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in conjunction with the Figures, wherein like reference numbers refer to similar items throughout the Figures, and:
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0032] As discussed above, embodiments of the present invention relate to vision measurement and therapy systems and particularly to an augmented reality-based system for measuring and treating vergence disorders, and methods of using the system.
[0033] Referring to the Drawings, as shown in
[0034] In operation, the headset 14 is first fitted on the patient's head and over the patient's eyes, whereupon calibration of the eye tracking technology 16 may be performed according to calibration procedures native to the headset 14. Calibration is meant to insure that the device accurately measures eye position. It is performed by projecting to the patient, on the headset 14, various geometric targets at various known positions in space. The spatial location of each target is known by the system 12, and the eye position of the patient (of each eye) is determined by the system. This information is used to determine when the subject/patient is fixating on the projected targets. By knowing the position of the target and the measured eye-movements, the system calibrates itself, so that the position of the targets and the alignment of the eyes are mathematically congruent. It is understood that it may be necessary to recalibrate the eye tracking technology 16, as may be appropriate, at other times during use of the system 10.
[0035] In an embodiment of the system 10, the computing device 12 may be programmed to send for display, on the headset 14, as represented in
[0036] Once SBV has occurred, a vergence demand may then be created by the system 10 by incrementally moving the target images 20 and 22 apart or together, either horizontally, vertically, or a combination of horizontally and vertically. At first, the patient's eyes should normally continue to track their respective targets 20 and 22, at least through small degrees of vergence demand, thereby maintaining SBV. Eventually, however, the vergence demand will become too great for the patient to maintain SBV, at which point one of the patient's eyes will deviate from its target, resulting in double vision (see
[0037] As noted, it is an advantage of the present invention that the occurrence of either SBV or diplopia, in the fusional vergence amplitude measurement procedure described above, may be determined accurately and automatically (and objectively) by the system 10 using the eye tracking technology 16 of the headset 14, rather than depending on subjective feedback from the patient.
[0038] Depending on the data obtained from the above vergence measurements (for example, certain amplitudes of fusional version in a patient), a vision care provider may determine that therapy is indicated in order to improve the amplitudes of fusional version to a more desirable number. For example, motor fusion functions at levels less than clinical norms are often associated with eye-strain or asthenopia. Excessive stress on the vergence system or inability to converge or diverge adequately (in the horizontal direction) or attain supra or infra vergence (in the vertical direction) may warrant therapeutic vergence treatment of the patient.
[0039] When therapeutic vergence treatment is warranted, embodiments of the system 10 may be utilized to perform therapeutic vergence treatment exercises to increase amplitudes of fusional vergence. For example, with both eyes of the patient on target (seeing the two independent targets 20 and 22 as one target 30), wherein SBV is initially attained, the system 10 may create a small vergence demand, such as by moving the images 20 and 22 apart, while the position and direction of gaze of the eyes is continuously monitored by the eye tracking technology 16 in conjunction with computing device 12. The degree of vergence demand may be incrementally or continuously increased until the point of diplopia (loss of fusion). In other words, this point of diplopia is when the system objectively determines, using the measured eye position, direction of gaze and known target positions 20 and 22, that the patient is now seeing two images rather than one. As noted above, the system 10 tracks both the time at which this occurs, and the position and direction of gaze of each eye 24 and 26 and each target 20 and 22, and stores this information. Once diplopia occurs (loss of fusion), as determined by using the eye tracking technology 16 (to determine each eye's position and direction of gaze) and known target positions 20 and 22, the computing device 12 may be programmed to automatically bring the images 20 and 22 together again until the point at which SBV is again attained. Again, the point at which SBV is regained is determined objectively by the system, using the eye position data from the headset 14 and known target positions 20 and 22 for each eye. This data, along with the time of regaining SBV, are stored by the system. Then, in order to continue exercising the eyes 24 and 26, the images 20 and 22 may again be incrementally or continuously increased again until a new point of diplopia is reached. By repetition of this exercise for a certain duration or number of iterations, the amplitude of fusion is gradually increased until SBV can be comfortably achieved by the patient to within a predetermined range of acceptable values. It is understood that similar vergence exercises may be performed by the system 10 automatically moving the target images 20 and 22 closer together instead of apart, and doing this in an iterative process, and that vergence may be in the horizontal direction, vertical direction, or a combination of horizontal and vertical directions. This repetitive process is designed to improve the vergence reflexes in patients.
[0040] Alternatively, a vision care provider, on reviewing the stored fusional vergence data and amplitude of fusional vergence, may direct the system regarding the duration or number of iterations of exercise, and/or the magnitudes of increasing/decreasing the separation of images, the duration of time between iterations, and various other parameters of the therapy. In practice, therapy sessions may typically be engaged at spaced intervals, over days, weeks, or months until the desired level of improvement is attained, based on the objective patient data determined and stored by the system.
[0041] As noted above regarding the fusional vergence amplitude measurement procedure, it is an advantage of the present invention that the occurrence of either SBV or diplopia, in the therapeutic vergence treatment procedure, as described herein, may be determined accurately, automatically and objectively by the system 10 using the eye tracking technology 16 of the headset 14, rather than depending on subjective feedback from the patient to tell the system when fusional vergence occurs or is lost.
[0042] As noted above, the system may also be used to objectively determine strabismus and phoria characteristics of a patient's eyes. In this case, an identical object (target) is presented to each eye 24 and 26 (see
[0043] Next, the above process is repeated, but blanking the left eye rather than the right eye. As above, an identical object (target) is presented to each eye. The system determines the exact position of each of the eyes. Next, the left image is eliminated (blanked), so that only the right eye is presented the target. If, when the left eye is blanked, the right eye moves to fixate on the target being presented to it (as determined by the system continuously monitoring the position of the right eye), the amount of movement (turn of the eye) is determined by the system (based on the system's knowledge of the initial position of the eye and the final, fixated position of the eye). This amount of movement is captured and logged by the system, as is the fact that a strabismus condition exists for the right eye. If, however, the system determines that the right eye did not need to move in order to be fixated on the target, the system determines if the left (blanked) eye moved. If it did move, the magnitude of that movement is determined by the system (based on the initial and final position of the left eye as determined by the system), and the system captures that a phoria exists for the left eye (and the magnitude of that phoria based on the difference between the initial and final positions of the left (blanked) eye.
[0044] It should be appreciated that both vertical and horizontal measurements may be taken in both cases in determining the existence (and magnitude) of phoria or strabismus conditions.
[0045] In an alternative embodiment, called, for example, “motor field”, the above procedures (measurement and treatment phoria and/or amount of strabismus) may be performed through a number of gaze positions. For example, in one embodiment, 9 positions are utilized: top left, top middle, top right, middle left, middle middle, middle right, bottom left, bottom middle, bottom right (see, e.g.
[0046] As can be seen, the system provides for objective measurement vergence, strabismus and phoria conditions using independent eye movement measurements. In an alternative embodiment, with regard to phoria and strabismus measurements, rather than extinguishing the right or left target, a white amorphous visual field may be substituted (in other words, the fusible target for the eye to be blanked is replaced by a white field with no fusible detail.
[0047] Referring to the drawings,
[0048] In some embodiments, as further illustrated in the block diagram of
[0049] In another embodiment, a method 200, generally illustrated in
[0050] In yet another embodiment, a method 300, generally illustrated in
[0051] In an alternative embodiment, both the position of each eye's target and the objectively measured position/orientation of each of the patient's eyes is simultaneously displayed on a separate display device visible to the vision care provider, along with indicators of when fusion has occurred or been lost, allowing the vision care provider to view in real-time what the patient is seeing and how the patient's eyes are responding. This can aide the vision care provider in adjusting parameters of the system (how much stress to subject the eyes to when incrementally separating targets to induce loss of fusion, duration between iterations, etc.). In addition, this allows the vision care provider to see if the patient is looking at the target.
[0052] In an alternative embodiment, when the system determines that there has been loss of fusion, it waits a predetermined amount of time (without moving the targets) to determine if the patient is able to regain fusion on their own. Once that time period has passed, and fusion has not been regained, the system will gradually move the targets back toward each other until fusion is regained, capturing both eye position and target position data through the process.
[0053] In an alternative embodiment, the system user can adjust the speed at which targets are moved relative to each other, and/or the amount of time that a patient is permitted to use the system to exercise the eyes through the iterative process discussed above.
[0054] In an alternative embodiment, the system stores, for each patient, the precise point at which fusion is lost when targets are separated, and, in therapy sessions, causes the targets to immediately be separated to that point of loss of fusion (rather than incrementally separating targets from a point of fusion), and continuously increments vergence demands away from that point, and back to that point, iteratively, to work the eye muscles right at the edge of loss of fusion.
[0055] In an alternative embodiment, input from an input device is utilized by the patient to demand separation of the targets, or to move targets together.
[0056] It should be appreciated that in the present invention, the system is able to determine, automatically and objectively, and without subjective patient input, which of the patient's eyes is not aligned to the target, unlike previous systems where this cannot be determined.
[0057] It should also be appreciated, that in the present system, the distance between the eyes and the targets is fixed, providing a reliable measurement of the parameters discussed above, whereas in previous systems, displaying images on a monitor where the distance between the patient's eyes and targets varies based on any head or body movement of the patient, decreasing the reliability of any system measurements.
[0058] As noted, this system provides objected data, rather than data determined by subjective input that may vary based on the age of the patient, attention span, length of time between when the patient realizes fusion has been lost and when it was actually lost, duration of time between patient perception of fusion loss and communication of that via patient manual input, honesty of patient, and other subjective factors.
[0059] As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method, or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
[0060] Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.
[0061] A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
[0062] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire-line, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
[0063] Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Unity, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the computing device 12, as a stand-alone software package, partly on the computing device 12 and partly on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the computing device 12 through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0064] Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0065] These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0066] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, cloud-based infrastructure architecture, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0067] The embodiments and examples set forth herein were presented in order to best explain the present invention and its practical application and to thereby enable those of ordinary skill in the art to make and use the invention. However, those of ordinary skill in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the teachings above without departing from the spirit and scope of the forthcoming claims.