System and method for measuring ciliary muscle activity

Abstract

The present disclosure relates to systems and methods for measuring ciliary muscle activity. Systems and methods for non-invasively assessing ciliary accommodation potentials in a phakic eye can include receiving a plurality of signals generated by a plurality of bipolar electrodes during a ciliary muscle assessment procedure, each of the plurality of signals indicative of an electric field associated with a ciliary muscle of a patient, and analyzing the signals to evaluate a ciliary accommodation potential of the patient.

Description

[0001] This application is a divisional application of the patent application with application number 201880067727.8, filed on October 16, 2018, and titled “System and method for measuring ciliary muscle activity”. TECHNICAL FIELD

[0002] The present disclosure relates generally to the field of ophthalmology. BACKGROUND

[0003] The human eye provides vision by transmitting light through a transparent outer portion called the cornea and focusing the image on the retina by way of the lens. The quality of the focused image depends on many factors, including the size and shape of the eye, and the transparency of the cornea and lens.

[0004] When aging or disease causes the lens to become less transparent, vision deteriorates because less light can be transmitted to the retina. This defect in the eye lens is medically known as a cataract. The treatment accepted for this condition is surgical removal of the lens and replacement of the lens function with an artificial intraocular lens (IOL).

[0005] In the United States, most cataract lenses are removed by a surgical technique known as phacoemulsification. During this procedure, an opening is made in the anterior capsule and a thin phacoemulsification cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquefies or emulsifies the lens so that it can be suctioned out of the eye. Once the diseased lens is removed, it is replaced with an IOL.

[0006] In a natural lens, far and near vision are provided by a mechanism known as accommodation. The natural lens is housed within a capsular bag and is soft in early life. The capsular bag is suspended on the ciliary muscle by zonular ligaments. Relaxation of the ciliary muscle tightens these zonular ligaments and elongates the capsular bag. As a result, the natural lens tends to flatten. Tensioning of the ciliary muscle relaxes the tension on the zonular ligaments, allowing the capsular bag and natural lens to assume a more rounded shape. In this manner, the natural lens can alternately focus on near and far objects.

[0007] As the lens ages, the lens becomes harder and less able to change its shape in response to tensioning of the ciliary muscle. In addition, the ciliary muscle loses flexibility and range of motion. This makes it more difficult for the lens to focus on near objects, a medical condition known as presbyopia. Presbyopia affects almost all adults between the ages of 45 and 50. In addition, patients can also suffer from other conditions, such as age-related macular degeneration (AMD), which can require even greater magnification to perform visual functions such as reading.

[0008] One approach to providing presbyopia correction is to use an electro-active optical element in an ophthalmic lens, such as an intraocular lens (IOL) or a contact lens. Such an electro-active element can be designed to change optical power (and thus the patient's focusing distance) in response to detection of ciliary muscle action or related electrical activity. Exemplary approaches are disclosed in U.S. Patent No. 9,226,818, entitled SENSORS FOR TRIGGERING ELECTRO-ACTIVE OPHTHALMIC LENSES, which is incorporated by reference herein in its entirety.

[0009] In advanced presbyopia, age-related degeneration of the muscle can inhibit the ability of the ciliary muscle to contract, and the electrical signals that accompany ciliary muscle movement can be attenuated or absent. Thus, there is an inherent risk with accommodating IOLs that rely on ciliary muscle-driven action: the muscle can not work, and the IOL can not work correctly. Thus, there is a need to determine and characterize electrical activity in the ciliary muscle, and a need for a pre-screening procedure to determine whether a patient has the ciliary muscle activity required to utilize such an electro-active ophthalmic lens. SUMMARY

[0010] According to certain embodiments, a method includes receiving a plurality of signals generated by a plurality of bipolar electrodes during a ciliary muscle assessment procedure, each of the plurality of signals indicative of an electric field associated with a ciliary muscle of a patient, and analyzing the signals to evaluate a ciliary muscle accommodation potential of the patient. The ciliary muscle assessment procedure can include focusing on one or more targets at different distances from the patient. The method can further include providing a contact lens to be applied to an eye of a patient, the contact lens including a plurality of bipolar electrodes. At least one of the bipolar electrodes can be aligned with a periphery of the ciliary muscle of the patient when applied to the eye of the patient.

[0011] In certain examples, analyzing the signals to evaluate a ciliary muscle accommodation potential of the patient includes identifying a subset of the signals corresponding to at least one of the bipolar electrodes aligned with a periphery of the ciliary muscle of the patient, calculating a value based on the identified subset of signals, and evaluating a ciliary muscle accommodation potential of the patient based on the calculated value. Calculating a value based on the identified subset of signals can include calculating a sum of the identified subset of signals. Evaluating a ciliary muscle accommodation potential of the patient based on the calculated value can include comparing the calculated sum of the identified subset of signals to a predetermined value.

[0012] In certain examples, the plurality of bipolar electrodes includes a plurality of concentric rings, and each concentric ring includes a plurality of segments. Identifying the subset of the signals corresponding to at least one of the bipolar electrodes aligned with a periphery of the patient's ciliary muscle can include identifying at least one signal from a segment of a first ring and identifying at least one signal from a segment of a second ring.

[0013] In certain embodiments, an ophthalmic system includes a contact lens configured to contact a surface of a patient's eye. The contact lens can include a plurality of bipolar electrodes each configured to generate a signal indicative of an electric field associated with a ciliary muscle of a patient. The system can further include a diagnostic system including a processor and a memory configured to receive a plurality of signals generated by the plurality of bipolar electrodes during a ciliary muscle assessment procedure, each of the plurality of signals indicative of an electric field associated with a ciliary muscle of a patient. The processor and memory of the diagnostic system can be further configured to analyze the received signals to identify a subset of signals corresponding to a subset of bipolar electrodes aligned with the patient's ciliary body and to calculate a value associated with the identified subset of electrodes. The system can further include a display communicatively coupled to the processor and configured to display the calculated value associated with the identified subset of electrodes.

[0014] In certain examples, the processor and memory of the diagnostic system are configured to analyze the signals to evaluate a ciliary muscle accommodation potential of the patient by identifying a subset of the signals corresponding to at least one of the bipolar electrodes aligned with a periphery of the patient's ciliary muscle and calculating a value based on the identified subset of signals.

[0015] Calculating a value based on the identified subset of signals can include calculating a sum of the identified subset of signals, and the processor and memory of the diagnostic system can be further configured to compare the calculated sum of the identified subset of signals to a predetermined value stored in the memory.

[0016] In certain embodiments, the plurality of bipolar electrodes includes a plurality of concentric rings, and each concentric ring can include a plurality of segments. Identifying the subset of the signals corresponding to at least one of the bipolar electrodes aligned with a periphery of the patient's ciliary muscle can include identifying at least one signal from a segment of a first ring and identifying at least one signal from a segment of a second ring.

[0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide a further explanation of the disclosure as claimed. Accordingly, additional aspects, features, and advantages of the disclosure will be apparent to one of ordinary skill in the art from the following. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings illustrate implementations of the systems, devices, and methods disclosed herein and together with the description, serve to explain the principles of the disclosure.

[0019] Figure 1 is a patient evaluation method for a ciliary driven ophthalmic device according to certain embodiments.

[0020] Figure 2 A depicts an electrode contact lens well aligned on a patient's eye.

[0021] Figure 2 B depicts an electrode contact lens misaligned on a patient's eye (off center, misaligned above).

[0022] Figure 3 An electrode contact lens is shown according to certain embodiments.

[0023] Figure 4 An electrode contact lens is shown according to certain embodiments.

[0024] Figure 5 A depicts an electrode contact lens well aligned on a patient's eye. Figure 3 of an electrode contact lens.

[0025] Figure 5 B depicts an electrode contact lens misaligned on a patient's eye (off center, misaligned above). Figure 3 of an electrode contact lens.

[0026] Figure 6 An ophthalmic system is shown according to certain embodiments.

[0027] These drawings will be better understood by reference to the following detailed description. DETAILED DESCRIPTION

[0028] Efforts are being made to develop accommodating IOLs that are designed to change the power of an ophthalmic lens, such as an IOL, in response to changes in the ciliary muscle. One sensing technology that has been relatively successful for detecting muscle activity is electromyography. Electromyography is a technique in which the electrical field pattern around a muscle is measured, such as by potential measurement, over time to determine the extent of muscle contraction. In contrast to methods such as calcium channel ion detection or other direct detection of neural signals, electromyography focuses on the electrical activity of the muscle itself and has proven to be a more reliable measure of muscle activity. Moreover, it can provide a continuous indication of the extent of muscle activity, particularly the extent of force exerted by the muscle, rather than a binary detection of neural signals.

[0029] Movement of the muscle fiber is triggered by depolarization within the muscle fiber, accompanied by movement of ions, which creates a change in the electrical field. As the depolarization travels down the muscle fiber, a biphasic electrical field signal is created that switches sign from positive to negative as the depolarization wave moves down the fiber. The electromyography sensor detects this change in the electrical field, such that muscle activity can be measured. Measurements in skeletal muscle have demonstrated that the intensity changes monotonically and generally linearly with the force exerted by the muscle, such that the electrical field can serve as an indicator of the force exerted by the muscle.

[0030] In application to ophthalmic lenses, particularly IOLs, the correlation between the extent of muscle activity needed in response to a visual stimulus, which can be observed as the accommodation demand, and the amount of electrical field in the muscle can be used to calibrate the lens. Although accommodation is ineffective later in life due to hardening of the lens and aging of the ciliary muscle and surrounding connective tissue, the ciliary muscle continues to contract even in presbyopic eyes. This can provide an indication of the accommodation demand that allows for a more coarse detection than previous sensing technologies, such as detection of neural activity or gross detection of electrical activity as a trigger for accommodation. Thus, rather than detecting a binary transition between near vision and distance vision, this system can allow for a continuous range of adjustments related to the electrical activity of the ciliary muscle tissue, which in turn can be calibrated based on the observed accommodation demand. This calibration can be based on an average response of a population; alternatively, the calibration can be patient-specific.

[0031] U.S. Patent No. 9,226,818, which is incorporated herein by reference, discloses an exemplary electroactive ophthalmic lens that includes an electromyography sensor configured to detect an electrical field of a ciliary muscle, generate a signal indicative of the electrical field, and adjust an optical power of an electroactive optical element based on the signal. In particular embodiments, the sensor provides automatic control of the electroactive lens. In other embodiments, the sensor provides a user control interface for operating the electroactive lens.

[0032] Most accommodating IOLs are designed to change optical power (and thus the patient’s focusing distance) in response to the action of the ciliary muscles. In some cases, the performance of such ophthalmic products is limited due to physiological limitations within the eye, including residual ciliary muscle force. For example, in advanced presbyopia, age-related degeneration of the ciliary muscles can reduce or can eliminate their contractile ability. Without adequate screening, such patients risk undergoing surgery with a premium accommodating IOL that will not work properly after implantation. Thus, accommodating IOLs or other ophthalmic devices that work by detecting ciliary muscle electrical activity as an indicator to change optical power cannot work effectively if the electrical signal obtained from the patient’s ciliary muscle activity is significantly attenuated or absent.

[0033] There are currently no techniques available to assess the ciliary muscle accommodation potential in a phakic eye (e.g., prior to removal of the natural lens for IOL implantation). Thus, embodiments of the present disclosure provide non-invasive screening techniques and tools for preoperative assessment of a patient’s ciliary electrical activity and evaluation of their accommodation potential. This can be achieved, for example, via sensing ciliary muscle electrical activity prior to implanting an accommodating IOL or applying a custom ciliary muscle driven accommodating contact lens as described herein. Some embodiments can identify, prior to surgery or purchase, eyes in which a ciliary muscle driven accommodating ophthalmic device will not function as expected, to guide decisions about whether such a device is suitable for a particular individual. While the following description focuses primarily on IOLs, the described techniques can also be used in ciliary muscle activity driven contact lenses or glasses.

[0034] Figure 1 is a high-level overview of a patient screening method 100 for ciliary driven ophthalmic devices according to certain embodiments. At step 101, a measurement device is applied to the patient’s eye. In certain examples, the measurement device comprises an electrode contact lens as described below. The lens can be positioned on the eye such that one or more electrodes in or on the contact lens are adjacent to, on, around, and / or within the ciliary muscles (or their perimeter / circumference) to acquire electrical signal data based on ciliary muscle movement.

[0035] At step 102, a ciliary function screening is performed. In one example, a preoperative examination can be performed by a care provider to determine and characterize the patient’s ciliary muscle activity. For example, once the electrode contact lens is placed on the eye, the patient can be instructed to view objects at different distances according to an established procedure, such as a near distance (e.g., within 40 cm) and a far distance (e.g., more than 3 m). As the patient changes (or attempts to change, as the case can be) focus to different target distances, the ciliary muscles attempt to change the power of the natural lens accordingly. This causes a change in the electrical field of the patient’s ciliary muscle(s) that can be detected by the electrode(s) on the contact lens and signaled.

[0036] Accordingly, at step 103, the electrical signals generated by the electrode(s) at each distance in response to the electric field of the ciliary muscle can be set to and received by the computer 606, processed and / or recorded for subsequent presentation and evaluation. In some cases, the electrical signals are transmitted from the electrodes of the lens to the computer 606 via wired or wireless communication. As noted below, multiple signals can be received from various electrodes on the lens during the screening procedure, and the received signals can be evaluated by the computer 606 (e.g., using summation, averaging, comparison, and / or statistical processing algorithms, etc.) in order to select the signals that provide the most accurate and / or reliable indication of ciliary muscle activity. The particular electrode signals selected can depend on the location of the contact lens on the patient's eye, as well as characteristics of the patient's eye itself. The computer 606 can also process the signals and convert them to numerical or other measurements that characterize ciliary muscle activity, responsiveness, strength, and / or accommodation ability. The raw or processed signal data can be output by the computer and displayed on the display 608.

[0037] At step 104, the results of step 103 are evaluated. The signal values or measurements generated and / or displayed at step 103 can be viewed and evaluated by the computer 606 and / or the care provider to make a surgical recommendation or selection for the patient (e.g., whether to recommend or provide a ciliary-driven accommodative device). Step 104 can be performed manually by the care provider, or automatically by the computer 606. For example, the care provider can review and evaluate the measurements of ciliary muscle activity generated at step 103 to determine whether they are above or below one or more predetermined thresholds, or whether they are within a predetermined range or target outcome that is considered suitable for utilization of a ciliary-driven ophthalmic device. In other examples, the computer 606 can execute instructions stored in memory to automatically analyze the measurements of ciliary muscle activity generated at step 103 and automatically perform such evaluation. Applicable thresholds, ranges, or targets for comparison can be stored in memory of the computer 606 and can be configured by the user.

[0038] If the measured ciliary muscle activity generated at step 102 is satisfactory and passes evaluation at step 104 (e.g., muscle activity is above a threshold, at a target, or within a predetermined range), the care provider can proceed to step 106. In this case, the ciliary muscle activity can be sufficient to support proper functioning of a ciliary-driven ophthalmic device, such as an electroactive accommodative IOL. In selecting or making a recommendation for the patient, the care provider can consider and evaluate the ciliary-driven ophthalmic device.

[0039] If the measured ciliary muscle activity produced at step 102 is unsatisfactory and does not pass evaluation at step 104 (e.g., muscle activity is below a threshold, is off target, or is outside a predetermined range), the care provider can proceed to step 108. In this case, the ciliary muscle activity can not be sufficient to support proper functioning of a ciliary-driven ophthalmic device such as an electroactive accommodating IOL, and the care provider can consider and evaluate alternatives to the ciliary-driven ophthalmic device when selecting or developing a recommendation for the patient.

[0040] Accordingly, certain embodiments of the present disclosure provide techniques for non-invasive screening for ciliary-driven ophthalmic devices including implantable IOLs.

[0041] The design and function of the ophthalmic system and electrode contact lens will now be described in more detail. Various electrode designs for characterizing and measuring ciliary muscle activity can be developed and used. For example, electrodes for measuring ciliary muscle electrical signals can include metal or wire adhered or embedded in a contact lens. Such a lens can be placed on the eye to measure ciliary electrical signals.

[0042] Generally, the position and spacing of the electrodes relative to the ciliary muscle location can affect the ability to detect electrical signals. For example, in the case of continuous electrodes (e.g., 360 degrees around the optical axis of the contact lens), when the electrode position is off center (e.g., misaligned above, as shown in FIGS. 1 1 A and 1 1 B) or moves on the eye (potentially due to gravity, eye movement, or blinking), the signal can deteriorate or potentially reverse as the electrodes move away from the muscle location. One approach to minimize the effects of moving the lens is to suction the lens onto the corneal surface. However, this can be uncomfortable and can not be entirely effective. Furthermore, this approach can not address potential signal changes related to ciliary muscle movement. Figure 2 B and Figure 5 B) or moves on the eye (potentially due to gravity, eye movement, or blinking), the signal can deteriorate or potentially reverse as the electrodes move away from the muscle location. One approach to minimize the effects of moving the lens is to suction the lens onto the corneal surface. However, this can be uncomfortable and can not be entirely effective. Furthermore, this approach can not address potential signal changes related to ciliary muscle movement.

[0043] Another factor that can affect the ability to measure ciliary electrical signal changes is a potential mismatch between the diameter of the ciliary muscle and the diameter(s) of the electrode(s). Indeed, even the diameter of the ciliary muscle can vary between patients. Furthermore, this can be a static issue or can change with accommodation (if the ciliary muscle is significantly contracted).

[0044] To address these and other potential difficulties regarding accurately measuring and characterizing ciliary muscle activity, certain embodiments employ specialized electrode designs. For example, multiple bipolar electrodes can be used. Such electrodes can be segmented or multi-faceted and can include, for example, one side of a ring of electrodes located outside the perimeter or circumference of the ciliary muscle and an opposite side electrode inside the perimeter or circumference of the ciliary muscle. This configuration can be used to cancel out signals and / or reduce overall signal amplitude.

[0045] Further, certain embodiments can divide the electrodes into segments or individual components to produce a more comprehensive map of the ciliary electrical activity. In such examples, different regions can be selected or ignored (manually by a care provider or automatically by the computer 606) as appropriate (e.g., based on alignment and position relative to the perimeter or circumference of the ciliary muscle) to better characterize the true electrical signal (i.e., to obtain accurate measurements of the electrical activity caused by ciliary muscle movement).

[0046] For example, each individual electrode segment of the electrode contact lens can be connected to an ophthalmic diagnostic system (e.g., the computer 606) that includes a processor and memory configured to receive, process, and display (e.g., via the display 608) measurements of detected ciliary muscle activity. A care provider can inspect the alignment of the individual electrode segments with the ciliary muscle of the patient to identify and select appropriate segments (e.g., those that are best aligned with the ciliary muscle) on which the evaluation is based, as described by step 104. In other examples, the diagnostic system automatically selects appropriate segments on which the evaluation is based. In different implementations, each segment can be continuously sampled or intermittently sampled using time-based multiplexing techniques. One or more of these features can be used to optimize signal characterization and account for variables such as external lens movement, ciliary muscle movement at the time of accommodation, and differences in eye anatomy, where otherwise misaligned signals from one side can degrade the opposite side as the electrode position changes.

[0047] Figure 2 A and Figure 2 B illustrates an example of a contact lens with two embedded circular electrodes for measuring ciliary muscle activity and demonstrates principles of the present disclosure. The eye 200 includes a ciliary muscle 202 indicated by the circle around the iris (not labeled). A transparent contact lens placed on the cornea of the eye 200 includes a reference electrode 204 and a measurement electrode 206. The measurement electrode 206 is sized to cover the perimeter of the ciliary muscle 202, while the reference electrode 204 is larger and further away from the ciliary muscle 202, outside the circumference. (In alternative embodiments, the reference electrode 204 can be smaller than the measurement electrode 206, further away from the ciliary body 202 but closer to the pupil of the eye 200.) The difference in electrical signals received from the reference electrode 204 and the measurement electrode 206 can be used to measure the amplitude of the electrical signal in the ciliary body 202. In one well-aligned example, as shown in A, the difference in signal strength between the reference electrode 204 and the measurement electrode 206 will be the same or similar at any angle. For example, the signal difference on the left side of the pupil of the eye 200 will be the same as the signal difference on the right side of the pupil, or the signal difference above or below. In certain examples, the measured signal can be determined by summing these differences across all angles (over 360 degrees). Figure 2 A and Figure 2 B illustrates an example of a contact lens with two embedded circular electrodes for measuring ciliary muscle activity and demonstrates principles of the present disclosure. The eye 200 includes a ciliary muscle 202 indicated by the circle around the iris (not labeled). A transparent contact lens placed on the cornea of the eye 200 includes a reference electrode 204 and a measurement electrode 206. The measurement electrode 206 is sized to cover the perimeter of the ciliary muscle 202, while the reference electrode 204 is larger and further away from the ciliary muscle 202, outside the circumference. (In alternative embodiments, the reference electrode 204 can be smaller than the measurement electrode 206, further away from the ciliary body 202 but closer to the pupil of the eye 200.) The difference in electrical signals received from the reference electrode 204 and the measurement electrode 206 can be used to measure the amplitude of the electrical signal in the ciliary body 202. In one well-aligned example, as shown in A, the difference in signal strength between the reference electrode 204 and the measurement electrode 206 will be the same or similar at any angle. For example, the signal difference on the left side of the pupil of the eye 200 will be the same as the signal difference on the right side of the pupil, or the signal difference above or below. In certain examples, the measured signal can be determined by summing these differences across all angles (over 360 degrees).

[0048] Figure 2 B demonstrates the same features as Figure 2 A, but where the reference electrode 204 and the measurement electrode 206 are misaligned above the ciliary muscle 202. In this example, the reference electrode 206 is positioned below the ciliary muscle 202, and the differential signal in this position (between the reference electrode 204 and the measurement electrode 206) can be significantly offset from the similar differential signal in the position shown in Figure 2 A. In some cases, the below signal measured in Figure 2 B (near the bottom of the electrodes 204, 206) can be the inverse of the signal in Figure 2 A.

[0049] In the above, neither the reference electrode 204 nor the measurement electrode 206 are well aligned with the ciliary muscle 202, and the measured above differential signal (near the top of the electrodes 204, 206) measured in Figure 2 B can be very small. Thus, compared to the measurements made in the arrangement shown in Figure 2 A, the signals measured in Figure 2 B can be significantly different over 360 degrees. Although an above shift is shown in this example, the relative shift between the electrodes 204, 206 and the ciliary body 202 can occur in any direction.

[0050] Figure 3 An electrode arrangement for a contact lens for ciliary activity detection is shown demonstrating certain embodiments that can help overcome difficulties caused by misalignment. In particular, the lens 300 includes four concentric electrode rings 301-304, each divided into four segments, shown as groups 310, 312, 314, and 316. The outer ring electrode 304 and each of the smaller rings 302, 303, and 304 can each measure electrical activity in each segment 310, 312, 314, and 316, providing readings at sixteen independent segments or channels. Although a total of sixteen segments or channels are shown in Figure 3 , the number of rings and their division can be changed as appropriate to optimize performance while managing complexity, as increasing the number of channels requires increasing the complexity of the electrical design and processing requirements. For example, certain embodiments can include two to six concentric electrode rings divided into two to six groups, providing 4 to 36 segments or channels. Other variations are contemplated within the scope of the present disclosure.

[0051] It is worth noting that the present disclosure is not limited to segmented ring-shaped electrode configurations as shown in Figure 3 . Other embodiments can include lenses with electrodes having different shapes, sizes, or arrangements. For example, Figure 4Embodiments of a lens 400 are shown that include an outer ring of electrodes 410 and an inner ring of electrodes 420, each including sixteen electrode segments. Thus, Figure 4 Embodiments can support up to 32 channels. Also, while a total of 32 channels are shown in Figure 4 , the number of electrodes and rings can be changed as appropriate to optimize performance while managing complexity, as increasing the number of channels requires increasing the complexity of the electrical design and processing requirements. For example, certain embodiments can include two to six concentric rings of electrodes, each including 3 to 20 electrodes, providing 6 to 120 channels. Other variations are contemplated within the scope of the present disclosure.

[0052] Figure 5 A possible situation resulting from applying a contact lens that would include electrode rings (the same as lens 300 shown in Figure 4 is shown. In Figure 5 A, the lens 300 is centered on the eye 200, and all four segments of the third ring from the center (corresponding to ring 303 of Figure 3 are well aligned with the periphery or perimeter of the ciliary muscle 202. Summing the signals produced by each of the four segments of ring 303 produces a signal comparable to that obtained from the measuring electrodes 206 shown in Figure 2 A - can be considered an accurate and reliable result.

[0053] In contrast, Figure 5 B, the lens 300 is off-center on the eye 200 (misaligned above, similar to Figure 2 B). Thus, in Figure 5 B, the segments of ring 303 are not well aligned with the ciliary muscle 202, and summing the signals produced by each of the four segments of ring 303 would produce a signal comparable to that obtained from the measuring electrodes 206 shown in Figure 2 B - is likely to be an unreliable and inaccurate result.

[0054] However, in Figure 5 B, the lower electrodes of ring 304 (toward the bottom of Figure 5 B, corresponding to segments 314 and 316 shown in Figure 3 are well aligned with the ciliary muscle 202. Similarly, the upper electrodes of ring 302 (toward the top of Figure 5 B, corresponding to segments 310 and 312 shown in Figure 3 are suitably aligned with the ciliary muscle 202. Thus, summing the signals produced by the two lower electrodes of ring 304 and the two upper electrodes of ring 302 produces a signal comparable to that obtained from the measuring electrodes 206 shown in Figure 2 A - can again be considered an accurate and reliable result.

[0055] In this way, a lens comprising multiple electrode segments configured to independently generate and transmit signals can be used to accurately assess ciliary muscle activity according to Figure 1 the method of even if the lens is not aligned with respect to the ciliary body. This can be accomplished by selecting signals from electrodes that are well aligned with the ciliary muscle. This selection can be performed manually by a care provider, or automatically by the computer 606, as discussed below.

[0056] Figure 6 An ophthalmic system 600 according to certain embodiments that can be used to perform the method 100 is illustrated. The system includes one or more electrode- contacting lenses 602 designed for placement on the corneal surface of a patient's eye in order to conduct a ciliary muscle assessment procedure. The lenses 602 can include multiple electrodes and segments as illustrated in Figure 3 and Figure 5 but are not limited to the arrangements illustrated in those embodiments.

[0057] Once the lens 602 is placed on the patient's eye, a care provider can perform the steps described above with respect to the steps 102 illustrated and described in Figure 1 In some cases, as the patient gazes at objects at different distances, the ciliary muscles attempt to change the focusing power of the natural lens accordingly. This causes a change in the electric field of one or more of the patient's ciliary muscles. At each distance, the electrical signals 604 generated by each electrode or channel of the lens 602 can be transmitted to and received by a computer 606 that includes a processor and memory configured to execute instructions for processing the signals 604. The signals 604 can be transmitted to the computer 606 via wired or wireless communication. In certain embodiments, as discussed above with respect to the example of Figure 5 B, particular segments or channels of the multi-electrode lens 602 that are aligned with the patient's ciliary body can be identified and selected by the computer 606.

[0058] The computer 606 includes one or more processors 612, and memory 614. The memory 614 can include persistent and volatile media, fixed and removable media, and magnetic and semiconductor media. The memory 614 is operable to store programs, code, scripts, instructions, data, and the like. The illustrated memory 614 includes sets or sequences of instructions, namely an operating system and an ophthalmic diagnostic program. The operating system can be a UNIX or UNIX-like operating system, such as the Linux® operating system, The system is an operating system (e.g., macOS, iOS) or another suitable operating system. Instructions and data stored in memory 614 are accessible and executable by processor 612 to perform the steps discussed herein. Processor 612 may be or include a general-purpose microprocessor and a dedicated coprocessor or another type of data processing device. In some cases, processor 612 performs high-level operations for the diagnostic evaluation of ciliary function discussed herein. Processor 612 may be configured to execute or interpret software, scripts, programs, functions, executable files, or other instructions stored in memory 614 to receive, interpret, process, and evaluate signals generated by electrodes during ciliary muscle screening (e.g., such as...). Figure 1 (as described in method 100). Therefore, computer 606 is particularly suited to perform ophthalmological procedures related to ciliary muscle function as described herein.

[0059] For example, the processor of computer 606 may execute instructions to compare and evaluate signals 604 received from each electrode or channel of lens 602 to determine and select the optimal signal for further processing and / or evaluation. In some examples, the processor of computer 604 may use the received signals to perform summation, averaging, comparison, and / or statistical processing algorithms to identify and select a subset of signals that provide the most accurate and / or reliable indication of ciliary muscle activity. In some examples, this may include identifying and selecting signals that are best located within and aligned with the periphery or boundary of the ciliary muscle based on algorithms executed by the processor. Algorithms executed by the processor may also include comparing each received signal with upper and lower threshold values, an average or median value (which may be calculated based on the received signal), or other markers that can be used to evaluate the quality and / or reliability of the received signal. As noted above, the selected subset of electrode signals may depend on the location of the contact lens on the patient's eye and the characteristics of the patient's eye itself.

[0060] Alternatively, instructions may be encoded as pre-programmed or reprogrammable logic circuits, logic gates, or other types of hardware or firmware components.

[0061] In some examples, a user may use an input device 610 (e.g., keyboard, mouse, touchscreen, voice recognition, etc.) to assist in identifying and selecting specific segments or channels of the multi-electrode lens 602 for evaluation steps. Alternatively, the computer 606 may automatically identify and select specific segments or channels of the multi-electrode lens 602 for evaluation steps based on the algorithm presented above.

[0062] Additionally, the processor of the computer 606 can execute instructions to process the raw signal data and convert them into numerical values or other measurements that characterize ciliary muscle activity, responsiveness, strength, and / or accommodation ability. The raw or processed signal data can be output by the computer and displayed on a display 608 (e.g., monitor, screen, heads-up display, tablet device, etc.). Based on the displayed data and information, the care provider can then proceed to step 104 and evaluate the results and data obtained from the multi-electrode lens 602. Additionally or alternatively, the processor of the computer 606 can compare the selected measurements and data to predetermined thresholds, targets, and ranges to provide notifications, recommendations, or alerts to the care provider via the display 608.

[0063] It should be noted that the processor of the computer 606 can include one or more CPUs, microprocessors, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), digital signal processors (DSPs), system on chip (SoC) processors, or similar components. The memory of the computer 606 can include volatile memory or non-volatile memory, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), removable media, or similar components. The memory of the computer 606 can store instructions for software programs and algorithms that, when executed by the processor, analyze the signals received from the lens 602 as described above. As used in the claims, the terms “processor,” “memory,” “instructions,” and the like refer to classes of structures that are well known to those of ordinary skill in the art. Accordingly, these terms should be understood to represent structural elements of the disclosed system and not functional elements.

[0064] Accordingly, embodiments of the present disclosure provide novel and useful systems and methods for preoperatively evaluating a patient’s ciliary electrical activity. Using the disclosed systems and methods, a care provider can identify, prior to surgery or purchase, eyes in which a ciliary muscle driven accommodating ophthalmic device will not function as expected, to guide decisions about whether such a device is appropriate for a particular individual. Conversely, using the disclosed systems and methods, a care provider can identify, prior to surgery or purchase, eyes in which a ciliary muscle driven accommodating ophthalmic device will likely function well, to guide decisions about whether such a device is appropriate for a particular individual.

[0065] One of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the specific exemplary embodiments described above. In this regard, while illustrative implementations have been shown and described, various modifications, changes, combinations, and alternatives can become apparent to a person of ordinary skill in the art from the foregoing detailed description. It is understood that such changes can be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is to be understood that the appended claims are intended to cover all such changes as fall within the scope of the present disclosure.

Claims

1. An ophthalmic system comprising: a contact lens configured to contact a surface of a patient's eye, the contact lens including a plurality of bipolar electrodes, the plurality of bipolar electrodes including a plurality of concentric rings, each concentric ring including a plurality of segments; and one or more processors and memory including instructions that, when executed by the one or more processors, are operable to: receive a plurality of signals generated by the plurality of bipolar electrodes during a ciliary muscle assessment procedure; and analyze the received signals to assess a ciliary muscle accommodation potential, the analyzing including at least one of: summing the received signals to identify a subset of the signals corresponding to a subset of the plurality of segments of a concentric ring aligned with the ciliary muscle; averaging the received signals to identify a subset of the signals corresponding to a subset of the plurality of segments of a concentric ring aligned with the ciliary muscle; or comparing each of the received signals to one of (a) upper and lower threshold values, (b) a mean of the received signals, or (c) a median of the received signals to identify a subset of the signals corresponding to a subset of the plurality of segments of a concentric ring aligned with the ciliary muscle; and a display communicatively coupled to the processors and configured to display a calculated value associated with the ciliary muscle accommodation potential.

2. The system of claim 1, wherein summing the received signals includes summing a first signal in a subset of signals generated by a first segment and a second signal in a subset of signals generated by a second segment.

3. The system of claim 1, wherein the instructions, when executed by the one or more processors, are operable to compare at least one of the summed received signals or the averaged received signals to a predetermined value to assess a ciliary muscle accommodation potential.

4. The system of claim 1, wherein the plurality of concentric rings includes at least three concentric rings.

5. A method for analyzing a ciliary muscle accommodation potential of a patient performed in a computer, comprising: receiving a plurality of signals generated by a plurality of bipolar electrodes in response to ciliary muscle activity, the plurality of bipolar electrodes including a plurality of concentric rings, each concentric ring including a plurality of segments; and analyzing the received signals to assess a ciliary muscle accommodation potential, the analyzing including at least one of: summing the received signals to identify a subset of the signals corresponding to a subset of the plurality of segments of a concentric ring aligned with the ciliary muscle; averaging the received signals to identify a subset of the signals corresponding to a subset of the plurality of segments of a concentric ring aligned with the ciliary muscle; or comparing each of the received signals to one of (a) upper and lower threshold values, (b) a mean of the received signals, or (c) a median of the received signals to identify a subset of the signals corresponding to a subset of the plurality of segments of a concentric ring aligned with the ciliary muscle.

6. The method of claim 5, further comprising providing a contact lens to be applied to the patient's eye, the contact lens including the plurality of bipolar electrodes.

7. The method of claim 5, wherein assessing a ciliary muscle accommodation potential includes comparing at least one of the summed received signals or the averaged received signals to a predetermined value.

8. The method of claim 5, wherein assessing ciliary accommodation potential comprises detecting changes in the received plurality of signals as the ciliary muscles change the degree of focus to focus on one or more different distance targets.

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