Method and apparatus for measuring ocular surface friction

Abstract

An apparatus and / or a method for measuring ocular surface friction are provided. In an example, the apparatus may include a strip and / or a measuring device configured to measure the ocular surface friction based upon a position of the strip. The strip may be inserted inside an eyelid of an eye. A strip pulling force may be applied to the strip. The strip pulling force may cause the strip to be released from the eye. The ocular surface friction associated with the eye may be measured based upon a characteristic, of the strip, when the strip is released from the eye.

Description

METHOD AND APPARATUS FOR MEASURING OCULAR SURFACE FRICTIONRELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 524,194, filed on June 29, 2023, entitled “A novel ocular surface friction measuring device,” which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to measuring ocular surface friction.BACKGROUND

[0003] Dry eye is a common condition where tears are insufficient to lubricate and nourish the eye, leading to discomfort, visual disturbances, and potential damage to the eye's surface. It can be caused by various factors, including aging, environmental conditions, medications, and / or health issues. Symptoms may include dryness, irritation, a gritty sensation, and / or blurred vision.SUMMARY

[0004] In accordance with the present disclosure, one or more computing devices, systems and / or methods are provided. In an example, an apparatus for measuring ocular surface friction is provided. The apparatus may include a strip and / or a biasing member configured to apply a biasing force to the strip to bias the strip to a resting position that is separated from a component of the apparatus by a first distance. Application of a strip pulling force to the strip may (i) increase the distance between the strip and the component while the strip pulling force overcomes the biasing force, and / or (ii) release the strip from an eyelid of an eye in response to the distance between the strip and the component reaching a second distance, greater than the first distance,associated with the biasing force applied by the biasing member and / or the strip pulling force overcoming a strip holding force associated with the eye. The apparatus may include an indicator configured to display an ocular surface friction measurement based upon the second distance.

[0005] In an example, an apparatus for measuring ocular surface friction is provided. The apparatus may include a strip and / or a measuring device configured to measure the ocular surface friction based upon a position of the strip.

[0006] In an example, a method for measuring ocular surface friction is provided. A strip of an apparatus may be inserted inside an eyelid of an eye. A strip pulling force may be applied to the strip. The strip pulling force may cause the strip to be released from the eye. An ocular surface friction associated with the eye may be measured based upon a characteristic, of the strip, when the strip is released from the eye.

[0007] In an example, a positioning device for positioning at least one of a strip of an apparatus or a housing structure of the apparatus in a target position relative to an eye of a person is provided. The positioning device includes (i) a sheath surrounding at least some of the housing structure and / or (ii) a plurality of legs coupled to the sheath.DESCRIPTION OF THE DRAWINGS

[0008] While the techniques presented herein may be embodied in alternative forms, the particular embodiments illustrated in the drawings are only a few examples that are supplemental of the description provided herein. These embodiments are not to be interpreted in a limiting manner, such as limiting the claims appended hereto.

[0009] Fig. 1 is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0010] Fig. 2A is an illustration of an apparatus while the apparatus is used to measure ocular surface friction, in accordance with some embodiments.

[0011] Fig. 2B is an illustration of an apparatus while the apparatus is used to measure ocular surface friction, in accordance with some embodiments.

[0012] Fig. 2C is an illustration of an apparatus while the apparatus is used to measure ocular surface friction, in accordance with some embodiments.

[0013] Fig. 3A is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0014] Fig. 3B is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0015] Fig. 3C is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0016] Fig. 3D is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0017] Fig. 3E is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0018] Fig. 3F is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0019] Fig. 3G is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0020] Fig. 4 is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0021] Fig. 5 is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0022] Fig. 6 is a flow chart illustrating an example method, in accordance with some embodiments.

[0023] Fig. 7 is an illustration of a strip for measuring ocular surface friction, in accordance with some embodiments.

[0024] Fig. 8 is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.

[0025] Fig. 9 is an illustration of an apparatus for measuring ocular surface friction, in accordance with some embodiments.DETAILED DESCRIPTION

[0026] Subject matter will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific example embodiments. This description is not intended as an extensive or detailed discussion of known concepts. Details that are known generally to those of ordinary skill in the relevant art may have been omitted, or may be handled in summary fashion.

[0027] The following subject matter may be embodied in a variety of different forms, such as methods, devices, components, and / or systems. Accordingly, this subject matter is not intended to be construed as limited to any example embodiments set forth herein. Rather, example embodiments are provided merely to be illustrative. Such embodiments may, for example, take the form of hardware, software, firmware, medicine, clothing design, or any combination thereof.

[0028] Dry eye disease is prevalent around the world, and accurate diagnosis may speed up patients' relief from discomfort and spare them unnecessary risk from severe disease, expense and / or exposure to potential side effects associated with some treatments. However, there is no definitive diagnostic test of dry eye disease. There is a need for tests to improve diagnosis, as well as progression tracking, so that appropriate treatment can be administered or titrated. Some professionals rely upon a questionnaire to be filled out by a patient to determine severity of dryness, which may be inaccurate due to inconsistencies between different peoples’ responses. Eye examination in the clinic also has its limitations, is variable on repeat examination, and / or rarely correlates with symptoms. Tests for dry eye can be expensive, time consuming, inconsistent in their measurements, and / or restricted in usefulness to a specific subtype of dry eye.

[0029] One or more devices and / or techniques for measuring ocular surface friction are provided. In some examples, an apparatus (e.g., an ocular tribometry device (OTD)) may include a strip, which may be insertable inside an eyelid of an eye. The apparatus may include a strip and / or a biasingmember configured to apply a biasing force to the strip to bias the strip to a resting position that is separated from a component of the apparatus by a first distance. Application of a strip pulling force to the strip may (i) increase the distance between the strip and the component while the strip pulling force overcomes the biasing force, and / or (ii) release the strip from an eyelid of an eye in response to the distance between the strip and the component reaching a second distance, greater than the first distance, associated with the biasing force applied by the biasing member and / or the strip pulling force overcoming a strip holding force associated with the eye. The apparatus may include an indicator configured to display an ocular surface friction measurement based upon the second distance. Such an apparatus may be an easy, safe, low-cost, scalable solution that can easily be implemented, may make it possible to measure ocular friction, a potentially critical ocular surface parameter that currently cannot measured, and / or can have broader applications, including various ocular surface diseases, eyelid pathology, and patients undergoing eyelid surgery that may change in tightness of the lid.

[0030] In some examples, the ocular surface friction measurement may be used for diagnosing and / or determining a severity of one or more eye conditions (e.g., one or more ocular surface diseases) associated with an eye of a person. For example, the one or more eye conditions may include dryness, conjunctival chalasis, superior limbic keratoconjunctivitis, atopy, graft-vs-host disease (e.g., the ocular surface friction measurement may be used to screen for graft-vs-host disease), one or more eyelid conditions (e.g., at least one of eyelid laxity, ectropion, and / or floppy eyelid syndrome, etc.) and / or other eye conditions.

[0031] Fig. 1 illustrates an apparatus 100 for measuring ocular surface friction, in accordance with some embodiments. The apparatus 100 may comprise a housing structure 114, a biasing member 102, a marker 104, a connecting line 106, a strip 108 and / or a housing head 1 10. The housing structure 114 may define a space in which at least a portion of the biasing member 102, at least a portion of the connecting line 106, or at least a portion of the marker 104 are disposed. In some examples, a visual scale 112 is displayed on a surface of the housing structure 114 (e.g., the visual scale 112may be printed on the surface and / or a label attached to the surface). In some examples, the housing structure 114 comprises a transparent material to allow visibility into the space in the housing structure 114 through the transparent material. In some examples, the marker 104 (and / or its position relative to the visual scale 112) is visible from outside the housing structure 114. In some examples, the marker 104 is a bright and / or distinguishable color (e.g., red, blue, etc.) to easily distinguish the marker 104 from other parts of the apparatus 100. In some examples, the housing structure 114 comprises glass, one or more plastics and / or one or more other suitable materials.

[0032] In some examples, the strip 108 is insertable inside an eyelid of an eye. In some examples, the strip 108 (and / or a surface and / or material of the strip 108) may have a known “roughness” (e.g., frictional coefficient) which may be inserted under the eyelid, between the undersurface of the eyelid and the eyeball (fornix). In some examples, the strip 108 may comprise paper, plastic, rubber and / or other suitable material. In some examples, the strip 108 comprises a Schirmer strip or similar. The strip 108 may be coated with a solution, such as a solution comprising polymer, silicone and / or other suitable material. In some examples, the strip 108 is coated with the solution to control the friction coefficient of the strip 108 and / or prevent absorption of fluid (e.g., tears) while in the eye. The solution may be hydrophobic, or hydrophilic, for example. In some examples, the strip 108 may be injection loaded. In some examples, the strip 108 may be clipped out of at least one of plastic, paper, etc. In some examples, the strip 108 is disposable. In some examples, the strip 108 is switched out for a new (disposable) strip after using the strip 108 in an ocular surface friction test and / or before using the apparatus 100 to perform another ocular surface friction test.

[0033] In some examples, the biasing member 102 comprises a spring (shown in Fig. 1), a stretchable band (e.g., at least one of a rubber band, an elastic band, etc.), an electronic force introducing unit (e.g., at least one of a solenoid, a motor, etc.) and / or other type of biasing component. The biasing member 102 may be configured to resist deformation from an initial state to a deformed state. The biasing member 102 may be configured to apply abiasing force to the strip 108 to bias the strip 108 to a resting position. The resting position of the strip 108 may correspond to the position, shown in Fig.1 , of the strip 108 relative to the housing structure 114 and / or other component of the apparatus 100. In some examples, when the strip 108 is in the resting position, the strip 108 may be separated from a component of the apparatus 100 (such as the housing head 110 or other component such as the housing structure 114, etc.) by a separation distance equal to a first distance D1 .

[0034] In some examples, the connecting line 106 and / or the biasing member 102 may extend through at least some of the space defined by the housing structure 114. The biasing member 102 may be coupled to a first portion of the connecting line 106 and / or the strip 108 may be coupled to a second portion of the connecting line 106. In some examples, the connecting line 106 comprises at least one of a wire, a cord, a rope, a string, a cable, a thread, a strand, a stretchable band (e.g., at least one of a rubber band, an elastic band, etc.), paper, cardboard, etc. In some examples, the biasing member 102 applies the biasing force to the strip 108 via the connecting line 106. Embodiments are contemplated in which the apparatus 100 does not comprise the connecting line 106, and / or where the biasing member 102 is coupled directly to the strip 108, and / or where one or more other types of components are used (in addition to or as an alternative to the connecting line 106) to (i) couple the biasing member 102 to the strip 108 and / or (ii) transfer the biasing force exerted by the biasing member 102 to the strip 108. In some examples, the biasing member 102 may be coupled to the housing head 110 (e.g., a first end 124 of the biasing member 102 is coupled to the housing head 110) and / or to the connecting line 106 (e.g., a second end 126 of the biasing member 102 is coupled to the connecting line 106).

[0035] In some examples, a strip pulling force is applied to the strip 108 (while the strip 108 is inserted in the eyelid of the eye). The strip pulling force may be applied to the strip 108 in a direction 120, which may be opposite to a direction 122 in which the biasing member 102 applies the biasing force to the strip 108. In some examples, application of the strip pulling force to the strip 108 moves the strip 108 (in the direction 120, for example) away from theresting position while the strip pulling force overcomes the biasing force applied by the biasing member 102 to the strip 108, which may cause the separation distance between the strip 108 and the housing head 110 to increase from the first distance D1 to a second distance greater than the first distance D1 . In some examples, the biasing force varies based upon the separation distance, wherein an increase of the separation distance may result in a greater magnitude of the biasing force. In some examples, application of the strip pulling force to the strip 108 causes elongation of the biasing member 102 (e.g., the spring and / or the stretchable band) from a first state (e.g., state of the biasing member 102 shown in Fig. 1) to an elongated state. In some examples, the biasing force may vary based upon a level of elongation of the biasing member 102 (e.g., the spring and / or the stretchable band), wherein an increase of the level of elongation may result in a greater magnitude of the biasing force. In example, the level of elongation may correspond to a difference between the first distance D1 and the second distance.

[0036] In some examples, the strip pulling force is applied to the strip 108 via application of a housing pulling force to the housing structure 114. The housing pulling force may be applied to the housing structure 114 manually by an operator (e.g., using the operator’s hand to handle the housing structure 114 and / or apply the housing pulling force by pulling the housing structure 114 away from the eye). Alternatively and / or additionally, the housing pulling force may be applied to the housing structure 114 automatically using a loading member and / or trigger assembly (using techniques provided herein with respect to Figs. 3A-3G and / or Fig. 4, for example). In some examples, the housing pulling force may be applied to the housing structure 114 in the direction 122 (and / or other direction).

[0037] In some examples, the strip pulling force applied to the strip 108 is caused by a combination of (i) the housing pulling force applied to the housing structure 114 and (ii) a strip holding force associated with the eye. The strip holding force may correspond to a force that keeps the strip 108 from being released (e.g., removed) from the eye. In some examples, the strip holding force is applied to the strip 108 in the direction 120 (and / or other direction). Insome examples, the strip holding force may be dependent upon a friction (and / or dryness) associated with the eye. For example, an increased level of friction (and / or dryness) associated with the eye may cause an increase of the strip holding force.

[0038] In some examples, as the strip pulling force applied to the strip 108 moves the strip 108 (in the direction 120, for example) away from the resting position, the biasing force applied by the biasing member 102 may increase, such as due, at least in part, to the biasing force being dependent upon the separation distance associated with the strip 108 and / or the level of elongation associated with the biasing member 102. In some examples, in response to the biasing force and / or the strip pulling force overcoming the strip holding force, the strip 108 may be released from the eye.

[0039] In some examples, a characteristic of the strip 108 and / or the biasing member 102 when the strip 108 is released from the eye (e.g., when the biasing force and / or the strip pulling force overcome the strip holding force) is indicative of and / or usable to determine an ocular surface friction measurement. In some examples, the characteristic may comprise the separation distance when the strip 108 is released from the eye (e.g., the separation distance that results in the biasing force and / or the strip pulling force overcoming the strip holding force). Alternatively and / or additionally, the characteristic may comprise the level of elongation of the biasing member 102 (e.g., the spring and / or the stretchable band) when the strip 108 is released from the eye (e.g., the level of elongation that results in the biasing force and / or the strip pulling force overcoming the strip holding force). In some examples, the characteristic (e.g., the separation distance and / or the level of elongation) may be usable to determine the ocular surface friction measurement due to the biasing force being dependent upon the separation distance and / or the level of elongation. For example, while the biasing force increases as the separation distance and / or the level of elongation are increased, the strip holding force is overcome once the separation distance and / or the level of elongation are sufficiently large enough to increase the biasing force to a magnitude that overcomes (in combination with the strip pulling force, for example) the strip holding force. In some examples, theocular surface friction measurement is indicative of and / or usable to (i) determine a measure of dryness of the eye, (ii) identify changes of the surface of the eye and / or (iii) identify changes in eyelids.

[0040] In some examples, the marker 104 may be disposed in the space defined by the housing structure 114, and / or may be coupled to a third portion of the connecting line 106. Alternatively and / or additionally, the marker 104 may be coupled to the biasing member 102. In some examples, application of the strip pulling force to the strip 108 causes movement of the marker 104 (in the direction 120, for example) from a first marker position (e.g., the position of the marker 104 shown in Fig. 1 ) relative to the housing structure 114 to a modified marker position relative to the housing structure 1 14. In some examples, the marker 104 remains in the modified marker position relative to the housing structure 114 in response the strip 108 being released from the eye. In some examples, the marker 104 provides a visual indication of the ocular surface friction measurement. For example, the ocular surface friction measurement may be indicated by a location of the modified marker position of the marker 104 relative to the visual scale 112.

[0041] Figs. 2A-2C illustrate use of the apparatus 100 to perform an ocular surface friction test to measure ocular surface friction associated with an eye 250 of a person, in accordance with some embodiments. In some examples, the ocular surface friction test may be performed after anesthesia in the eye 250, while in some examples, the ocular surface friction test may be performed without performing anesthesia in the eye 250. In some examples, the strip 108 is inserted in an eyelid of the eye 250 to position the strip 108 in a testing position relative to the eye 250. In some examples, the strip 108 may be inserted inside the eyelid of the eye 250 in a manner similar to that of inserting a Schirmer strip for conducting a Schirmer test, for example.

[0042] Fig. 2A illustrates the apparatus 100 when the strip 108 is in the testing position relative to the eye 250, in accordance with some embodiments. For example, the strip 108 may be inserted in a lower eyelid. In some examples, when the strip 108 is in the testing position, at least a portion of the strip 108 is lodged between (and / or is in contact with) an undersurface of the lower eyelid and an ocular surface of a first portion (e.g.,lower portion) of the eye 250 (e.g., a lower portion of the eyeball, such as fornix, of the eye 250). In some examples, a second visual scale (not shown) may be printed on the strip 108. The second visual scale may be usable for an operator (e.g., a healthcare professional, such as a nurse, technician, a physician, etc. that is administrating an ocular surface friction test on the person using the apparatus 100) to gauge how deep the strip 108 has been inserted in the eye 250.

[0043] Embodiments are contemplated in which the strip 108 is inserted in an upper eyelid of the eye. For example, at least a portion of the strip 108 may be lodged between (and / or may be in contact with) an undersurface of the upper eyelid and an ocular surface of a second portion (e.g., upper portion) of the eye 250. Thus, the techniques provided herein may be used for measuring ocular surface friction associated with various portions of eye 250 (e.g., various portions of the eyeball, the upper eyelid and / or the lower eyelid).

[0044] In some examples, the separation distance between the strip 108 and the housing head 110 may be equal to about the first distance D1 . In some examples, while the strip 108 is in the testing position relative to the eye 250, the housing pulling force may be applied to the housing structure 114 (in the direction 122, for example), which may cause the strip pulling force to be applied to the strip 108 (in the direction 120, for example). Application of the housing pulling force and / or the strip pulling force may move the housing structure 114 (in the direction 122, for example) away from the eye when the biasing force is overcome by the housing pulling force and / or the strip pulling force.

[0045] Fig. 2B illustrates the apparatus 100 during application of the housing pulling force and / or the strip pulling force. In some examples, the application of the housing pulling force and / or the strip pulling force may increase the separation distance from the first distance D1 to a second distance D2. In some examples, housing pulling force and / or the strip pulling force may cause elongation of the biasing member 102 (e.g., the spring and / or the stretchable band) from the first state (e.g., state of the biasing member 102 shown in Fig. 2A) to an elongated state (e.g., state of the biasingmember 102 shown in Fig. 2B). In some examples, the level of elongation may correspond to a third distance D3, which may correspond to a difference between the first distance D1 and the second distance D2. In some examples, the second distance D2 may be associated with the biasing force and / or the strip pulling force overcoming the strip holding force (applied by the eye 250 to the strip 108, for example). For example, once the separation distance reaches the second distance D2, the biasing force may reach a magnitude that overcomes (in combination with the strip pulling force, for example) the strip holding force. In some examples, the application of the housing pulling force and / or the strip pulling force may cause the movement of the marker 104 (in the direction 120, for example) from a first marker position (e.g., the position of the marker 104 shown in Fig. 2A) relative to the housing structure 114 to a modified marker position (e.g., a position of the marker 104 shown in Fig. 2B) relative to the housing structure 114.

[0046] In some examples, once the separation distance reaches the second distance D2, the strip holding force associated with the eye 250 may be overcome by the biasing force and / or the strip pulling force such that the strip 108 is released from the eye 250. Fig. 2C illustrates the apparatus 100 after the strip 108 is released from the eye 250. In some examples, the strip 108 being released from the eye 250 causes (i) the biasing member 102 to return from the elongated state to the first state and / or (ii) the strip 108 to return to the resting position relative to the housing structure 1 14 and / or other component of the apparatus 100 (e.g., the strip 108 may be separated from the housing head 110 by about the first distance D1 ). In some examples, in response to the strip 108 being released from the eye 250, the marker 104 may remain in the modified marker position or change to a new marker position. Thus, the operator may view the marker 104 and / or the visual scale 112 to determine an ocular surface friction measurement (e.g., about 3 in Fig. 2C) indicated by the apparatus 100. For example, the operator may visually compare the position (e.g., the modified marker position and / or the new marker position) of the marker 104 with the visual scale 1 12 to determine the ocular surface friction measurement.

[0047] Figs. 3A-3G illustrate the apparatus 100 comprising a first positioning device 300 for positioning the strip 108 and / or the housing structure 114 in a target position (e.g., the testing position of the strip 108) relative to an eye of a person, in accordance with some embodiments. Fig. 3A illustrates a first perspective view of the apparatus 100 with the first positioning device 300. Fig. 3B illustrates a second perspective view of the apparatus 100 with the first positioning device 300.

[0048] In some examples, the first positioning device 300 comprises a positioning device head 302, a body 304, a sheath 306 extending through the body 304 and / or a first plurality of legs. Although three legs of the first plurality of legs are depicted, other numbers of legs of the first plurality of legs (e.g., two legs, four legs, five legs, etc.) are within the scope of the present disclosure. In some examples, the sheath 306 is coupled to the positioning device head 302. In some examples, legs of the first plurality of legs are coupled to the sheath 306 (e.g., the legs may be coupled to the body 304, which may be coupled to the sheath 306). In some examples, the sheath 306 surrounds at least some of the housing structure 114. In some examples, while the sheath 306 surrounds at least some of the housing structure 114, the strip 108 extends through and / or is positioned outside an end 318 of the sheath 306.

[0049] In some examples, the first plurality of legs comprise a first leg 312a, a second leg 312b and / or a third leg 312c. In some examples, the first leg 312a may comprise a first base 314a, the second leg 312b may comprise a second base 314b, and / or the third leg 312c may comprise a third base 314c. In some examples, while the housing structure 1 14 is at least partially surrounded by the sheath 306, an operator (e.g., a healthcare professional) uses the first positioning device 300 to position the strip 108 and / or the housing structure 114 in the target position relative to the eye of the person. In some examples, the operator positions the strip 108 and / or the housing structure 114 in the target position by placing bases 314a, 314b and / or 314c of the first plurality of legs at respective regions of the person (e.g., one or more regions of the person’s face and / or head, such as at least one of a forehead of the person, a cheek of the person, a temple of the person, aneyebrow area of the person, and / or one or more other regions of the person’s face and / or head). The target position of the strip 108 and / or the housing structure 114 may correspond to the position, shown in Fig. 2A, of the strip 108 and / or the housing structure 114 relative to the eye 250.

[0050] In some examples, it may be appreciated that using the first positioning device 300 to position the strip 108 and / or the housing structure 114 in the target position to perform ocular surface friction tests may provide for improved repeatability, accuracy and / or precision of the ocular surface friction tests (as compared to attempting to position the strip 108 and / or the housing structure 114 manually without assistance from the first positioning device 300 which may provide for more consistent positioning of the strip 108 and / or the housing structure 114 across the ocular surface friction tests, and / or more consistent directions, such as direction 322, in which the housing structure 114 is pulled across the ocular surface friction tests).

[0051] In some examples, the apparatus 100 comprises a loading member 330 (shown in Fig. 3D) and / or a trigger assembly. In some examples, the loading member 330 is configured to apply the housing pulling force to the housing structure 114. In some examples, the loading member 330 comprises a spring (shown in Fig. 3D), a stretchable band (e.g., at least one of a rubber band, an elastic band, etc.), an electronic force introducing unit (e.g., at least one of a solenoid, a motor, etc.) and / or other type of loading component. The trigger assembly may be operable to trigger the loading member 330 to move the housing structure 114 in a direction 322 (shown in Figs. 3A and 3D) (e.g., a direction away from the eye of the person being tested) via application of the housing pulling force to the housing structure 114. In some examples, the direction 322 corresponds to the direction 122 (shown in Fig. 1).

[0052] In some examples, the trigger assembly comprises the positioning device head 302 and / or the housing head 110. For example, the positioning device head 302 may define an opening 320. In some examples, when the housing head 110 is in a first housing head position relative to the positioning device head 302 (e.g., the position of the housing head 110 shown Figs. 3A- 3B), the positioning device head 302 inhibits movement of the housing head110 in the direction 322. In some examples, when the housing head 110 is in a second housing head position relative to the positioning device head 302, the housing head 110 clears the opening 320 to allow the housing pulling force applied by the loading member 330 to the housing structure 114 to move the housing structure 114 in the direction 322 (shown in Figs. 3A and 3D). A size of the housing head 110 and / or a size of the opening 320 may be configured such that the housing head 110 to be able to clear the opening 320 when the housing head 110 has the second housing head position. In some examples, the housing head 110 is twisted in a twisting direction 324 (by the operator, for example) to shift from the first housing head position to the second housing head position. Embodiments are contemplated in which the trigger assembly comprises a clipping mechanism used to trigger the loading member 330 to move the housing structure 114 in the direction 322.

[0053] In some examples, it may be appreciated that using the loading member 330 and / or the trigger assembly to apply the housing pulling force to the housing structure 114 to perform ocular surface friction tests may provide for improved repeatability, accuracy and / or precision of the ocular surface friction tests (as compared to attempting to pull on the housing structure 114 manually without assistance from the loading member 330 which may provide for more consistent magnitudes of the housing pulling force across the ocular surface friction tests, and improved orientation of the apparatus 100).

[0054] Fig. 3C illustrates a cross-sectional view of the apparatus 100 with the first positioning device 300. For simplicity, some components (including the biasing member 102, the marker 104, the connecting line 106, the strip 108, the first plurality of legs, the loading member 330, and / or one or more other components) of the apparatus 100 are not depicted in Fig. 3C.

[0055] Fig. 3D illustrates a cross-sectional view of the apparatus 100 with the first positioning device 300. For simplicity, some components (including the biasing member 102, the marker 104, the connecting line 106, the strip 108, the first plurality of legs, and / or one or more other components) of the apparatus 100 are not depicted in Fig. 3D. In some examples, the loading member 330 surrounds at least some of the housing structure 114. In some examples, the loading member 330 is coupled to the positioning device head302 (e.g., a first end 332 of the loading member 330 is coupled to the positioning device head 302) and / or to the housing structure 114 (e.g., a second end 334 of the loading member 330 is coupled to the housing structure 114).

[0056] Fig. 3E illustrates a cross-sectional view of the apparatus 100 with the first positioning device 300. For simplicity, some components (including the first plurality of legs, the loading member 330, and / or one or more other components) of the apparatus 100 are not depicted in Fig. 3E.

[0057] Figs. 3F-3G illustrates views of the apparatus 100 with the first positioning device 300, in accordance with some embodiments. For simplicity, some components (including the first plurality of legs and / or one or more other components) of the apparatus 100 are not depicted in one or more of the views in Figs. 3F-3G.

[0058] Fig. 4 illustrates a perspective view of the apparatus 100 comprising a second positioning device 400 for positioning the strip 108 and / or the housing structure 114 in the target position relative to the eye of the person, in accordance with some embodiments. In some examples, the second positioning device 400 comprises a sheath 406 and / or a second plurality of legs. Although two legs of the second plurality of legs are depicted, other numbers of legs of the first plurality of legs (e.g., three legs, four legs, five legs, etc.) are within the scope of the present disclosure. In some examples, legs of the second plurality of legs are coupled to the sheath 406. In some examples, the sheath 406 surrounds at least some of the housing structure 114. In some examples, while the sheath 406 surrounds at least some of the housing structure 114, (i) the strip 108 extends through and / or is positioned outside a first end 418 of the sheath 406, and / or (ii) the housing head 1 10 is positioned outside (and / or is in contact with) a second end 420 of the sheath 406.

[0059] In some examples, the second plurality of legs comprise a first leg 412a and / or a second leg 412b. In some examples, legs of the second plurality of legs are foldable. In some examples, the first leg 412a is foldable via a first hinge 414a and / or the second leg 412b is foldable via a second hinge 414b. In some examples, the first leg 412a comprises a first base 416aand / or the second leg 412b comprises a second base 416b. In some examples, while the housing structure 1 14 is at least partially surrounded by the sheath 406, an operator (e.g., a healthcare professional) uses the second positioning device 400 to position the strip 108 and / or the housing structure 114 in the target position relative to the eye of the person. In some examples, the operator positions the strip 108 and / or the housing structure 114 in the target position by placing hinges 414a and / or 414b and / or bases 416a and / or 416b of the second plurality of legs at respective regions of the person (e.g., one or more regions of the person’s face and / or head, such as at least one of a forehead of the person, a cheek of the person, a temple of the person, an eyebrow area of the person, and / or one or more other regions of the person’s face and / or head). The target position of the strip 108 and / or the housing structure 114 may correspond to the position, shown in Fig. 2A, of the strip 108 and / or the housing structure 114 relative to the eye 250.

[0060] In some examples, it may be appreciated that using the second positioning device 400 to position the strip 108 and / or the housing structure 114 in the target position to perform ocular surface friction tests may provide for improved repeatability, accuracy and / or precision of the ocular surface friction tests.

[0061] In some examples, the apparatus 100 comprises a second loading member (not shown) and / or a second trigger assembly. In some examples, the second loading member is configured to apply the housing pulling force to the housing structure 114. In some examples, the second loading member comprises a spring (e.g., the spring 330 shown in Fig. 3D), a stretchable band (e.g., at least one of a rubber band, an elastic band, etc.), an electronic force introducing unit (e.g., at least one of a solenoid, a motor, etc.) and / or other type of loading component. The second trigger assembly may be operable to trigger the second loading member to move the housing structure 114 in a direction 422 (e.g., a direction away from the eye of the person being tested) via application of the housing pulling force to the housing structure 114. In some examples, the direction 422 corresponds to the direction 122 (shown in Fig. 1 ).

[0062] In some examples, the second trigger assembly comprises a button 402 and / or the sheath 406. In some examples, a force is applied to the button 402 (by a finger of the operator, for example) to operate the button 402. In some examples, applying the force to the button 402 causes the sheath 406 (and / or another component of the apparatus 100) to open a path for and / or otherwise loosen a grip on the housing structure 1 14, which may allow the housing pulling force applied by the second loading member to move the housing structure 118 in the direction 422.

[0063] In some examples, it may be appreciated that using the second loading member and / or the second trigger assembly to apply the housing pulling force to the housing structure 114 to perform ocular surface friction tests may provide for improved repeatability, accuracy and / or precision of the ocular surface friction tests.

[0064] Fig. 5 illustrates an apparatus 500 for measuring ocular surface friction, in accordance with some embodiments. The apparatus 500 may comprise a housing structure 514, an electronic device 502, a strip 508 and / or a pulling head 510. The housing structure 514 may define a space in which at least a portion of the electronic device 502 is disposed. In some examples, a visual scale 512 is displayed on a surface of the housing structure 514 (e.g., the visual scale 512 may be printed on the surface and / or a label attached to the surface). In some examples, the housing structure 514 comprises a transparent material to allow visibility into the space in the housing structure 514 through the transparent material. In some examples, the electronic device 502 is visible from outside the housing structure 514. In some examples, the housing structure 514 comprises glass, one or more plastics and / or one or more other suitable materials.

[0065] In some examples, the strip 508 is insertable inside an eyelid of an eye. In some examples, the strip 508 may have one, some or all of the features, characteristics, and / or uses provided herein with respect to the strip 108.

[0066] In some examples, the electronic device 502 comprises a second biasing member. The second biasing member may comprise a spring, a stretchable band (e.g., at least one of a rubber band, an elastic band, etc.), anelectronic force introducing unit (e.g., at least one of a solenoid, a motor, etc.) and / or other type of biasing component. The second biasing member may be configured to apply a biasing force to the strip 508 to bias the strip 508 to a resting position. The resting position of the strip 508 may correspond to the position, shown in Fig. 5, of the strip 508 relative to the housing structure 514 and / or other component of the apparatus 500. In some examples, when the strip 508 is in the resting position, the strip 508 may be separated from a component of the apparatus 500 (such as the pulling head 510 or other component such as the housing structure 514, etc.) by a separation distance equal to a fourth distance D4.

[0067] In some examples, a strip pulling force is applied to the strip 508 (while the strip 508 is inserted in the eyelid of the eye). The strip pulling force may be applied to the strip 508 in a direction opposite to a direction in which the second biasing member applies the biasing force to the strip 508. In some examples, application of the strip pulling force to the strip 508 moves the strip 508 away from the resting position while the strip pulling force overcomes the biasing force applied by the second biasing member to the strip 508, which may cause the separation distance between the strip 508 and the pulling head 510 to increase from the fourth distance D4 to a fifth distance greater than the fourth distance D4. In some examples, the biasing force varies based upon the separation distance, wherein an increase of the separation distance may result in a greater magnitude of the biasing force.

[0068] In some examples, the strip pulling force is applied to the strip 508 via application of a housing pulling force to the housing structure 514. The housing pulling force may be applied to the housing structure 514 manually by an operator (e.g., using the operator’s hand to handle the housing structure 514 and / or apply the housing pulling force by pulling the housing structure 514 away from the eye). Alternatively and / or additionally, the housing pulling force may be applied to the housing structure 514 automatically using a loading member and / or trigger assembly (using techniques provided herein with respect to Figs. 3A-3E and / or Fig. 4, for example).

[0069] In some examples, the strip pulling force applied to the strip 508 is caused by a combination of (i) the housing pulling force applied to the housingstructure 514 and (ii) a strip holding force associated with the eye. The strip holding force may correspond to a force that keeps the strip 508 from being released (e.g., removed) from the eye. In some examples, the strip holding force may be dependent upon a friction (and / or dryness) associated with the eye. For example, an increased level of friction (and / or dryness) associated with the eye may cause an increase of the strip holding force.

[0070] In some examples, as the strip pulling force applied to the strip 508 moves the strip 508 away from the resting position, the biasing force applied by the second biasing member may increase, such as due, at least in part, to the biasing force being dependent upon the separation distance associated with the strip 508 and / or the level of elongation associated with the second biasing member. In some examples, in response to the biasing force and / or the strip pulling force overcoming the strip holding force, the strip 508 may be released from the eye.

[0071] In some examples, a characteristic of the strip 508 and / or the second biasing member when the strip 508 is released from the eye (e.g., when the biasing force and / or the strip pulling force overcome the strip holding force) is indicative of and / or usable to determine an ocular surface friction measurement. In some examples, the characteristic may comprise the separation distance when the strip 508 is released from the eye (e.g., the separation distance that results in the biasing force and / or the strip pulling force overcoming the strip holding force). In some examples, the characteristic (e.g., the separation distance) may be usable to determine the ocular surface friction measurement due to the biasing force being dependent upon the separation distance. For example, while the biasing force increases as the separation distance is increased, the strip holding force is overcome once the separation distance is sufficiently large enough to increase the biasing force to a magnitude that overcomes (in combination with the strip pulling force, for example) the strip holding force.

[0072] In some examples, the electronic device 502 comprises a measuring device (e.g., a digital measuring device) configured to determine the ocular surface friction measurement based upon the characteristic. In some examples, the electronic device 502 comprises a digital display, such asat least one of a seven-segment display, a dot matrix display, a liquid crystal display (LCD), a touchscreen and / or other type of display. In some examples, the digital display displays an indication of the ocular surface friction measurement. In some examples, the electronic device 502 comprises a communication module. The communication module may transmit content indicative of the ocular surface friction measurement to a device (e.g., a phone, a tablet, a laptop, a computer, a wearable device, a smart device, a television, any other type of computing device, hardware and / or software). In some examples, the device controls a graphical user interface to display an indication of the ocular surface friction measurement.

[0073] In some examples, the device and / or the electronic device 502 perform one or more operations, based upon the ocular surface friction measurement, to determine an eye condition associated with the eye (e.g., dryness, conjunctival chalasis, superior limbic keratoconjunctivitis, atopy, graft-vs-host disease, one or more eyelid conditions, etc.) and / or a severity of the eye condition. In some examples, the device controls the graphical user interface to display an indication of the eye condition and / or the severity. Alternatively and / or additionally, the digital display of the electronic device 502 may display an indication of the eye condition and / or the severity.

[0074] In some examples, the apparatus 500 is operated to perform an ocular surface friction test using one, some or all of the techniques provided herein with respect to using the apparatus 100 to perform an ocular surface friction test.

[0075] An embodiment of measuring ocular surface friction is illustrated by an example method 600 of Fig. 6. At 602, a strip of an apparatus may be inserted inside an eyelid of an eye. At 604, a strip pulling force may be applied to the strip. The strip pulling force may cause the strip to be released from the eye. At 606, an ocular surface friction associated with the eye may be measured based upon a characteristic, of the strip, when the strip is released from the eye (e.g., a distance between the strip and a component of the apparatus when the strip is released from the eye).

[0076] Fig. 7 illustrates a strip 702 for measuring ocular surface friction, in accordance with some embodiments. Some embodiments provide for usingthe strip 702 (by itself, for example) to perform an ocular surface friction test to determine an ocular surface friction associated with an eye of a person. In some examples, the strip 702 is insertable inside an eyelid of the eye. In some examples, the strip 702 may have one, some or all of the features, characteristics and / or uses provided herein with respect to the strip 108.

[0077] In some examples, the strip 702 is inserted in an eyelid of the eye to position the strip 702 in a testing position relative to the eye, such as using one or more of the techniques provided herein, such as with respect to Fig. 2A. In some examples, once the strip 702 is in the testing position, the strip 702 is pulled (manually by an operator’s hand, for example) in a direction away from the eye to cause the strip 702 to be released from the eye. A characteristic of the strip 702 after being pulled and / or released from the eye may be indicative of and / or usable to determine an ocular surface friction measurement. In some examples, the characteristic may correspond to a tear line 704 (and / or a perforation and / or a tear and / or other type of characteristic). For example, a location of the characteristic (and / or a distance D5 between the tear line 704 and an end of the strip 702) may depend upon a friction associated with the eye. In some examples, a third visual scale (not shown) may be printed on the strip 702. The third visual scale may be usable for an operator to determine the ocular surface friction measurement (e.g., the third visual scale may indicate various friction values for various locations along the strip 702).

[0078] Fig. 8 illustrates an apparatus 800 for measuring ocular surface friction, in accordance with some embodiments. The apparatus 800 may comprise a housing structure 802, a strip 806 with an increasing friction gradient, a marker 806 and / or a connecting line 804. In some examples, the connecting line 804 comprises at least one of a wire, a cord, a rope, a string, a cable, a thread, a strand, a stretchable band (e.g., at least one of a rubber band, an elastic band, etc.), a spring, paper, cardboard, etc. The housing structure 802 may define a space in which at least a portion of the connecting line 804 and / or the marker 806 (which may be coupled to the connecting line 804) is disposed.

[0079] In some examples, the apparatus 800 is operated to perform an ocular surface friction test associated with an eye of a person, such as using one, some or all of the techniques provided herein with respect to using the apparatus 100. In some examples, the ocular surface friction test may be performed after anesthesia in the eye, while in some examples, the ocular surface friction test may be performed without performing anesthesia in the eye. In some examples, the strip 806 is inserted in an eyelid (e.g., lower eyelid and / or lower eyelid) of the eye to position the strip 806 in a testing position relative to the eye. In some examples, the strip 806 may be inserted inside the eyelid of the eye in a manner similar to that of inserting a Schirmer strip for conducting a Schirmer test, for example.

[0080] In some examples, while the strip 806 is in the testing position relative to the eye, a housing pulling force may be applied to the housing structure 802, which may cause a strip pulling force to be applied to the strip 806. In some examples, application of the strip pulling force to the strip 806 causes elongation of a third biasing member (e.g., at least one of a spring, a stretchable band, an electronic force introducing unit, etc.) of the apparatus 800 from a first state to an elongated state. Application of the housing pulling force and / or the strip pulling force may move the housing structure 802 away from the eye when the biasing force applied by a third biasing member (e.g., at least one of a spring, a stretchable band, an electronic force introducing unit, etc.) of the apparatus 800 is overcome by the housing pulling force and / or the strip pulling force. In some examples, as the strip pulling force applied to the strip 806 moves the strip 806, the biasing force applied by the third biasing member may increase, such as due, at least in part, to the biasing force being dependent upon a distance by which the strip 806 is moved from a resting position relative to the housing structure 802 and / or a level of elongation associated with the third biasing member.

[0081] In some examples, the housing pulling force and / or the strip pulling force may cause the biasing force to reach a magnitude that overcomes (in combination with the strip pulling force, for example) a strip holding force associated with the eye. In some examples, the application of the housing pulling force and / or the strip pulling force may cause the movement of themarker 806 from a first marker position relative to the housing structure 802 to a modified marker position relative to the housing structure 802.

[0082] In some examples, once the strip holding force associated with the eye is overcome by the biasing force and / or the strip pulling force, the strip 806 may be released from the eye. In some examples, the strip 806 being released from the eye causes the third biasing member to return from the elongated state to the first state. In some examples, in response to the strip 806 being released from the eye, the marker 806 may remain in the modified marker position or change to a new marker position. Thus, the operator may view the marker 806 and / or a visual scale on the housing structure 802 to determine an ocular surface friction measurement indicated by the apparatus 800. For example, the operator may visually compare the position (e.g., the modified marker position and / or the new marker position) of the marker 806 with the visual scale to determine the ocular surface friction measurement.

[0083] Fig. 9 illustrates views of the apparatus 100, in accordance with some embodiments.Table 1

[0084] Table 1 provides ocular surface friction measurements determined using the techniques provided herein. The ocular surface friction measurements may comprise in vitro measurements. The ocular surface friction measurements may be determined by performing ocular surface friction tests using the techniques shown in and / or described with respect to Figs. 2A-2C and / or other parts of the present disclosure. The ocular surface friction measurements may include (i) an average ocular surface friction for people impacted by dry eye, (ii) an average ocular surface friction for people with a first type of artificial tears drops and / or a first amount of artificial tears drops, (iii) an average ocular surface friction for people with a second type of artificial tears drops and / or a second amount of artificial tears drops, and / or(iv) an average ocular surface friction for people with an artificial tears ointment.

[0085] According to some embodiments, an apparatus for measuring ocular surface friction is provided. The apparatus includes a strip (e.g., strip 108, strip 508, etc.) and / or a measuring device (e.g., at least one of the housing structure 114, the biasing member 102, the marker 104, the connecting line 106, the housing head 110, the electronic device 502, etc.) configured to measure the ocular surface friction based upon a position of the strip.

[0086] According to some embodiments, an apparatus for measuring ocular surface friction is provided. The apparatus includes a strip; a biasing member configured to apply a biasing force to the strip to bias the strip to a resting position that is separated from a component of the apparatus by a first distance, wherein application of a strip pulling force to the strip: (i) increases the distance between the strip and the component while the strip pulling force overcomes the biasing force, and (ii) releases the strip from an eye in response to the distance between the strip and the component reaching a second distance, greater than the first distance, associated with the biasing force applied by the biasing member and / or the strip pulling force overcoming a strip holding force associated with the eye; and an indicator configured to display an ocular surface friction measurement based upon the second distance.

[0087] According to some embodiments, the apparatus includes a housing structure housing the biasing member, wherein the strip pulling force is applied to the strip via application of a housing pulling force to the housing structure.

[0088] According to some embodiments, the apparatus includes a loading member configured to apply the housing pulling force to the housing structure; and a trigger assembly operable to trigger the loading member to move the housing structure in a direction away from the eye via the application of the housing pulling force to the housing structure.

[0089] According to some embodiments, the apparatus includes a positioning device for positioning the strip and / or the housing structure in a target position relative to the eye, wherein the positioning device comprises (i) a sheath surrounding at least some of the housing structure, and (ii) a plurality of legs coupled to the sheath.

[0090] According to some embodiments, the apparatus includes a connecting line extending through a space defined by the housing structure, wherein (i) the biasing member is coupled to a first portion of the connecting line, and (ii) the strip is coupled to a second portion of the connecting line.

[0091] According to some embodiments, the indicator includes a marker, within the space defined by the housing structure, coupled to a third portion of the connecting line.

[0092] According to some embodiments, the application of the strip pulling force to the strip causes movement of the marker from a first marker position relative to the housing structure to a modified marker position relative to the housing structure.

[0093] According to some embodiments, the marker remains in the modified marker position relative to the housing structure in response to release of the strip from the eye.

[0094] According to some embodiments, the biasing force varies based upon a change to the distance between the strip and the component.

[0095] According to some embodiments, the indicator comprises a digital indicator.

[0096] According to some embodiments, the biasing member comprises a spring and / or a stretchable band.

[0097] According to some embodiments, the application of the strip pulling force to the strip causes elongation of the spring and / or the stretchable band from a first state to an elongated state.

[0098] According to some embodiments, the biasing member comprises an electronic force introducing unit.

[0099] According to some embodiments, an apparatus for measuring ocular surface friction is provided. The apparatus includes a strip; and a measuring device configured to measure the ocular surface friction based upon a position of the strip.

[0100] According to some embodiments, the strip is insertable inside an eyelid of an eye.

[0101] According to some embodiments, the apparatus includes an indicator configured to display an indication of the ocular surface friction measured by the measuring device.

[0102] According to some embodiments, the indicator comprises an analog indicator.

[0103] According to some embodiments, the indicator comprises a digital indicator.

[0104] According to some embodiments, a method for measuring ocular surface friction is provided. The method includes inserting a strip of an apparatus inside an eyelid of an eye; applying a strip pulling force to the strip, wherein the strip pulling force causes the strip to be released from the eye; and measuring an ocular surface friction associated with the eye based upon a characteristic, of the strip, when the strip is released from the eye.

[0105] According to some embodiments, the method includes displaying an indication of the ocular surface friction.

[0106] According to some embodiments, a positioning device for positioning at least one of a strip of an apparatus or a housing structure of the apparatus in a target position relative to an eye of a person is provided. The positioning device includes a sheath surrounding at least some of the housing structure and a plurality of legs coupled to the sheath.

[0107] According to some embodiments, each leg of the plurality of legs comprises a base configured for placement upon a region of at least one of a face of the person or a head of the person.

[0108] According to some embodiments, a method is provided wherein the method includes at least one aspect as described in the present disclosure and / or shown in the figures.

[0109] According to some embodiments, a method is provided wherein the method includes plural aspects as described in the present disclosure and / or shown in the figures.

[0110] According to some embodiments, an apparatus is provided wherein the apparatus includes at least one aspect as described in the present disclosure and / or shown in the figures.

[0111] According to some embodiments, an apparatus is provided wherein the apparatus includes plural aspects as described in the present disclosure and / or shown in the figures.

[0112] As used in this application, "component," "module," "system", "interface", and / or the like are generally intended to refer to a computer- related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a controller and the controller can be a component. One or more components may reside within a process and / or thread of execution and a component may be localized on one computer and / or distributed between two or more computers.

[0113] Unless specified otherwise, “first,” “second,” and / or the like are not intended to imply a temporal aspect, a spatial aspect, an ordering, etc. Rather, such terms are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first object and a second object generally correspond to object A and object B or two different or two identical objects or the same object.

[0114] Moreover, "example" is used herein to mean serving as an instance, illustration, etc., and not necessarily as advantageous. As used herein, "or" is intended to mean an inclusive "or" rather than an exclusive "or". In addition, "a" and "an" as used in this application are generally be construedto mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Also, at least one of A and B and / or the like generally means A or B or both A and B. Furthermore, to the extent that "includes", "having", "has", "with", and / or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprising”.

[0115] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least some of the claims.

[0116] Furthermore, the claimed subject matter may be implemented as a method, apparatus, or article of manufacture using standard programming and / or engineering techniques to produce software, firmware, hardware, or any combination thereof to control a computer to implement the disclosed subject matter. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer- readable device, carrier, or media. Of course, many modifications may be made to this configuration without departing from the scope or spirit of the claimed subject matter.

[0117] Various operations of embodiments are provided herein. In an embodiment, one or more of the operations described may constitute computer readable instructions stored on one or more computer and / or machine readable media, which if executed will cause the operations to be performed. The order in which some or all of the operations are described should not be construed as to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated by one skilled in the art having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment provided herein. Also, it will be understood that not all operations are necessary in some embodiments.

[0118] Also, although the disclosure has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. The disclosure includes all such modifications and alterations and is limited only by the scope of the following claims. In particular regard to the various functions performed by the above described components (e.g., elements, resources, etc.), the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure. In addition, while a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

Claims

CLAIMSWhat is claimed is:1 . An apparatus for measuring ocular surface friction, comprising: a strip; a biasing member configured to apply a biasing force to the strip to bias the strip to a resting position that is separated from a component of the apparatus by a first distance, wherein application of a strip pulling force to the strip: increases the distance between the strip and the component while the strip pulling force overcomes the biasing force; and releases the strip from an eye in response to the distance between the strip and the component reaching a second distance, greater than the first distance, associated with at least one of the biasing force applied by the biasing member or the strip pulling force overcoming a strip holding force associated with the eye; and an indicator configured to display an ocular surface friction measurement based upon the second distance.

2. The apparatus of claim 1 , comprising: a housing structure housing the biasing member, wherein the strip pulling force is applied to the strip via application of a housing pulling force to the housing structure.

3. The apparatus of claim 2, comprising: a loading member configured to apply the housing pulling force to the housing structure; and a trigger assembly operable to trigger the loading member to move the housing structure in a direction away from the eye via the application of the housing pulling force to the housing structure.

4. The apparatus of claim 2, comprising:a positioning device for positioning at least one of the strip or the housing structure in a target position relative to the eye, wherein the positioning device comprises: a sheath surrounding at least some of the housing structure; and a plurality of legs coupled to the sheath.

5. The apparatus of claim 2, comprising: a connecting line extending through a space defined by the housing structure, wherein: the biasing member is coupled to a first portion of the connecting line; and the strip is coupled to a second portion of the connecting line.

6. The apparatus of claim 5, wherein the indicator comprises: a marker, within the space defined by the housing structure, coupled to a third portion of the connecting line.

7. The apparatus of claim 6, wherein the application of the strip pulling force to the strip causes movement of the marker from a first marker position relative to the housing structure to a modified marker position relative to the housing structure.

8. The apparatus of claim 7, wherein the marker remains in the modified marker position relative to the housing structure in response to release of the strip from the eye.

9. The apparatus of claim 1 , wherein: the biasing force varies based upon a change to the distance between the strip and the component.

10. The apparatus of claim 1 , wherein the indicator comprises a digital indicator.11 . The apparatus of claim 1 , wherein the biasing member comprises at least one of a spring or a stretchable band.

12. The apparatus of claim 11 , wherein the application of the strip pulling force to the strip causes elongation of at least one of the spring or the stretchable band from a first state to an elongated state.

13. The apparatus of claim 1 , wherein the biasing member comprises an electronic force introducing unit.

14. An apparatus for measuring ocular surface friction, comprising: a strip; and a measuring device configured to measure the ocular surface friction based upon a position of the strip.

15. The apparatus of claim 14, wherein the strip is insertable inside an eyelid of an eye.

16. The apparatus of claim 14, comprising: an indicator configured to display an indication of the ocular surface friction measured by the measuring device.

17. The apparatus of claim 16, wherein the indicator comprises an analog indicator.

18. The apparatus of claim 16, wherein the indicator comprises a digital indicator.

19. A method for measuring ocular surface friction, comprising: inserting a strip of an apparatus inside an eyelid of an eye; applying a strip pulling force to the strip, wherein the strip pulling force causes the strip to be released from the eye; and measuring an ocular surface friction associated with the eye based upon a characteristic, of the strip, when the strip is released from the eye.

20. The method of claim 19, wherein: the characteristic comprises a distance between the strip and a component of the apparatus.21 . A positioning device for positioning at least one of a strip of an apparatus or a housing structure of the apparatus in a target position relative to an eye of a person, the positioning device comprising: a sheath surrounding at least some of the housing structure; and a plurality of legs coupled to the sheath.

22. The positioning device of claim 21 , wherein: each leg of the plurality of legs comprises a base configured for placement upon a region of at least one of a face of the person or a head of the person.

23. A method, comprising: at least one aspect as described in any one of the preceding claims.

24. A method, comprising: at least one aspect as described in any combination of some or all of the preceding claims.

25. A method, comprising: plural aspects as described in any one of the preceding claims.

26. A method, comprising: plural aspects as described in any combination of some or all of the preceding claims.

27. An apparatus, comprising: at least one aspect as described in any one of the preceding claims.

28. An apparatus, comprising:at least one aspect as described in any combination of some or all of the preceding claims.

29. An apparatus, comprising: plural aspects as described in any one of the preceding claims.

30. An apparatus, comprising: plural aspects as described in any combination of some or all of the preceding claims.

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