Gripping structure for film removal

Abstract

A surgical instrument includes a flexible outer gripping member and a flexible inner gripping member for stripping a membrane from the retina of a patient's eye. A surgical instrument includes a handle and at least one actuator. The outer tube has a proximal end mounted to the handle. The outer gripping member and the inner gripping member project outwardly from the distal end of the outer tube or are configured to project outwardly from the distal end of the outer tube. The at least one actuator may be used to move at least one of the outer gripping member and the inner gripping member relative to the other such that the inner gripping member and the outer gripping member are brought together to grip the membrane of the retina.

Description

Background Art

[0001] The internal limiting membrane (ILM) is a thin, transparent membrane located between the vitreous humor and the retina of the eye. The ILM plays a role in the formation of the eye but is not necessary for normal function of the adult eye. The ILM may pull on the retina and cause conditions such as macular holes, macular pucker, vitreomacular traction syndrome, diabetic macular edema, and cystoid macular edema secondary to inflammatory or veno-occlusive disease and other conditions. An epiretinal membrane (ERM) is a membrane that may form on the retina due to damage to the retina, such as from a posterior vitreous detachment.

[0002] It may be necessary to peel the ILM or ERM from the retina to prevent damage to the retina. Peeling of the ILM or ERM may also be necessary in preparation for a surgical procedure on the retina. To peel the ILM or ERM, a surgical instrument is inserted through a cannula in the patient's eye. Forceps or a specialized scraper typically extend from the instrument and are used to lift a flap in the ILM or ERM. The flap is then grasped with the forceps, and the ILM or ERM is peeled from the retina using a circular motion. However, excessive force on the forceps may result in puncture of the retina.

[0003] Therefore, it would be an advance in the art to reduce the risk of retinal damage caused by ILM or ERM detachment. Summary of the Invention

[0004] The present disclosure generally relates to film stripping tools.

[0005] In certain aspects, a membrane stripping tool includes concentric flexible rings. For example, certain aspects provide a surgical instrument comprising a handle and an actuator mounted on the handle. An outer tube has a proximal end mounted to the handle. The outer ring extends outward from the distal end of the outer tube. An inner ring extends outward from the distal end of the outer tube and is positioned within the outer ring. The inner ring is coupled to the actuator and is configured to move relative to the outer ring in response to movement of the actuator.

[0006] In some aspects, the membrane stripping tool includes independently controlled scrapers. For example, some aspects provide an ophthalmic surgical instrument for stripping a retinal membrane, the ophthalmic surgical instrument comprising a handle. A first actuator and a second actuator are mounted on the handle. The outer tube has a proximal end mounted to the handle. The outer arm has an outer scraper secured thereto, and the inner arm has an inner scraper secured thereto. The first actuator is configured to control extension of the outer arm from the outer tube, and the second actuator is configured to control movement of the inner arm relative to the outer arm.

[0007] The following description and the associated drawings set forth in detail certain illustrative features of the one or more embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings depict certain aspects of one or more embodiments and therefore should not be considered to limit the scope of the disclosure.

[0009] Figure 1A is an isometric view of a surgical instrument having a grasping structure including concentric rings, according to certain embodiments. Figure 1B According to some embodiments Figure 1A A cross-sectional view of the concentric rings in FIG.

[0010] Figure 2 According to some embodiments, Figure 1A and Figure 1B Isometric view of an alternative embodiment of an actuator of a gripping structure.

[0011] Figure 3 is a method for actuating a motor according to some embodiments. Figure 1A and Figure 1B Cross-sectional view of the concentric ring mechanism of the gripping structure.

[0012] Figure 4A is shown in an open configuration according to certain embodiments Figure 1A and Figure 1B Isometric view of the concentric rings of the gripping structure. Figure 4B is shown in an open configuration according to certain embodiments Figure 1A and Figure 1B Isometric view of concentric rings of a gripping structure, where the alignment structure of the inner ring engages with the outer ring.

[0013] Figure 5A is shown in a closed configuration according to certain embodiments Figure 1A and Figure 1B Isometric view of the concentric rings of the gripping structure. Figure 5B is a diagram showing, in part, the Figure 1A and Figure 1B Isometric view of the concentric rings of gripping structure extending on the outer tube.

[0014] Figures 6A to 6C is a diagram illustrating the use of Figure 1A and Figure 1B Cross-sectional view of the gripping structure peeling off the ILM.

[0015] Figure 7 is a diagram showing how the Figure 1A and Figure 1B Isometric view of the ILM with the gripping structure peeled off.

[0016] Figure 8Ais an isometric view of a surgical instrument having another grasping structure including independently actuated curved scrapers, according to certain embodiments.

[0017] Figure 8B According to some embodiments Figure 8A Isometric view of a curved scraper in FIG, having barbs on its lower edge.

[0018] Figure 9 According to some embodiments, Figure 8A and Figure 8B Isometric view of an alternative embodiment of an actuator of a gripping structure.

[0019] Figure 10 is a method for actuating a motor according to some embodiments. Figure 8A and Figure 8B A cross-sectional view of the mechanism of the arc scraper of the grabbing structure.

[0020] Figure 11A is a diagram showing an extended Figure 8A and Figure 8B Isometric view of a single curved scraper.

[0021] Figure 11B are shown extending but offset from each other according to some embodiments Figure 8A and Figure 8B Isometric view of two curved scrapers.

[0022] Figure 11C is shown brought together to grasp the membrane flap according to some embodiments Figure 8A and Figure 8B Isometric view of a curved scraper.

[0023] Figure 12 is a diagram showing how the Figure 8A and Figure 8B Isometric view of the ILM with the gripping structure peeled off.

[0024] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0025] Various aspects of the present disclosure provide surgical instruments for removing a membrane from a patient's retina. In certain aspects, the surgical instrument includes a gripping structure comprising a flexible ring. In certain other aspects, the surgical instrument includes a gripping structure comprising independently actuated curved scrapers. It should be noted that, as used herein, the distal end of a component refers to the end closer to the patient's body, while the proximal end of a component refers to the end facing away from the patient's body or closer to, for example, the handle of the surgical instrument.

[0026] Figure 1A A surgical instrument 100 is shown that includes a handle 102 sized and contoured to be grasped by the hand of a surgeon performing an ophthalmic surgical procedure, such as removing a retinal membrane, including an ILM or ERM, from an eye of a patient, in accordance with certain embodiments described herein. A grasping structure 104 may extend from a distal end of an outer tube 106 that further includes a proximal end connected to the handle 102. The handle 102 may have one or more manual control structures (e.g., an actuation mechanism) disposed thereon. Figure 1A In the embodiment of the present invention, the manual control structure includes a slide 108 and clamshell arms 110a, 110b. The manual control structure shown is only exemplary, and other manual control structures can also be used, such as Figure 2 The deformable basket and second slide are shown.

[0027] exist Figure 1A In the embodiment of the present invention, the gripping structure 104 is implemented as an outer ring 112 and an inner ring 114. The outer ring 112 can be referred to as an outer gripping member of the gripping structure 104, and the inner ring 114 can be referred to as an inner gripping member of the gripping structure 104. In some embodiments, the outer tube 106 and / or the inner ring 114 can translate relative to the outer ring 112. For example, one of the slider 108 and the clamshell arms 110a, 110b is coupled to the outer tube 106, and the other of the slider 108 and the clamshell arms 110a, 110b is coupled to the inner ring 114. In use, the outer tube 106 can be extended over the outer ring 112 and the inner ring 114, such as when the outer tube 106 is inserted into or withdrawn from a cannula (e.g., a trocar cannula) inserted into a patient's eye. The outer tube 106 can then be withdrawn or retracted, thereby extending the outer ring 112 and the inner ring 114 relative to the outer tube 106. And as discussed in more detail below, the inner ring 114 may then translate toward the outer ring 112 in order to capture the membrane between the outer ring 112 and the inner ring 114 .

[0028] The outer ring 112 and the inner ring 114 can be made of a highly flexible material such as Nitinol (nickel-titanium alloy), spring steel, or other materials. The high flexibility enables the outer ring 112 and the inner ring 114 to elastically deform so as to fit within the outer tube 106 and, when extended from the outer tube 106, expand to a size that is much wider than the outer diameter of the outer tube 106, such as at least two times, four times, eight times, or at least 16 times the outer diameter of the outer tube 106.

[0029] In the illustrated embodiment, the outer ring 112 has ends 112a, 112b secured to an inner tube 116, which is slidably positioned within the outer tube 106. The inner tube 114 has ends 114a, 114b secured to an inner rod 118, which is slidably positioned within the inner tube 116. The outer tube 106, inner tube 116, and inner rod 118 may be made of nitinol, stainless steel, spring steel, a rigid polymer, or other materials.

[0030] The outer tube 106 defines a longitudinal direction 120a that is parallel and collinear with the axis of symmetry of the outer tube 106. The axes of symmetry of the inner tube 116 and the inner rod 118 are substantially collinear (e.g., within 0.5 mm) with the longitudinal direction 120a and substantially parallel (e.g., within 5 degrees) with the longitudinal direction 120a. A transverse direction 120b can also be defined as perpendicular to the longitudinal direction 120a, such that the ends 112a, 112b of the outer ring 112 are offset from one another along the transverse direction 120b, and the ends 114a, 114b of the inner ring 114 are offset from one another along the transverse direction 120b. A vertical direction 120c can be defined as perpendicular to both the longitudinal direction 120a and the transverse direction 120b.

[0031] The outer ring 112 may include straight portions 112c, 112d extending from the ends 112a, 112b, respectively. The straight portions 112c, 112d may intersect a plane comprising the longitudinal direction 120a and the transverse direction 120b ("longitudinal-transverse plane"). The straight portions 112c, 112d may deviate from each other in the longitudinal-transverse plane, i.e., flare outwardly from each other as the distance from the distal end of the outer tube 106 increases. As used herein, "straight" may be understood as having a radius of curvature greater than 1 cm (centimeter) in the longitudinal-transverse plane. As used herein, the longitudinal-transverse plane includes a plane comprising both the longitudinal direction 120a and the transverse direction 120b.

[0032] The straight portions 112c, 112d may be connected to each other by a rounded end portion 112e. The rounded end portion 112e may be: (a) formed to maintain a rounded shape in the absence of external forces; or (b) the result of the outer ring 112 being bent and the ends 112a, 112b being fastened to the inner tube 116. The rounded shape may be circular, elliptical, or any arbitrary rounded shape.

[0033] The rounded end portion 112e can be fastened to the straight portions 112c, 112d by the flexible portions 112f, 112g. The flexible portions 112f, 112g have a reduced height (e.g., perpendicular to the longitudinal-transverse plane) and / or thickness (e.g., parallel to the longitudinal-transverse plane) relative to one or both of the rounded end portion 112e and the straight portions 112c, 112d. For example, in the illustrated embodiment, the thickness of the flexible portions 112f, 112g is substantially the same (e.g., within 10%) as the thickness of the straight portions 112c, 112d and the rounded end portion 112e, while the height of the flexible portions 112f, 112g is between 0.25 and 0.75 times or between 0.4 and 0.6 times the height of the straight portions 112c, 112d and the rounded end portion 112e. As in Figure 1A As is apparent in FIG. 1 , there may be a smooth transition between the reduced cross-section of the flexible portions 112f, 112g and the cross-section of the rounded end portion 112e and the straight portions 112c, 112d.

[0034] Flexible portions 112f, 112g can act as living hinges, thereby facilitating rotation of rounded end portion 112e relative to straight portions 112c, 112d. In other embodiments, there is no discontinuous flexible portion. In such embodiments, some or all of the extension between rounded end portion 112e and ends 112a, 112b provides flexibility.

[0035] It is desirable that the lower surface 132 of the rounded end portion 112e is relatively parallel to the retina to reduce the risk of puncture. In response to pressure applied by the membrane on the rounded end portion 112e during use, the rounded end portion 112e will rotate until the lower surface 132 of the rounded end portion 112e rests on the membrane, thereby increasing the surface area in contact with the membrane and reducing the risk of puncture. The cross-sectional shape of the rounded end portion 112e can have a height (e.g., perpendicular to the longitudinal-transverse plane) that is much greater than the thickness (e.g., parallel to the longitudinal-transverse plane) so that the rounded end portion 112e is substantially undeflected in a plane parallel to the longitudinal direction 120a and the vertical direction 120c (the "longitudinal-vertical plane"), such that the height is at least two, four, eight, or more times the thickness. This can facilitate the lower surface 132 of the rounded end portion 112e providing a wide surface that resists penetration of the retina.

[0036] In some implementations, the flexible portions 112f, 112g can further define a bend without any deforming force, such that the rounded end portion 112e defines an angle 112h relative to the longitudinal-transverse plane and is lifted above the longitudinal-transverse plane. The angle 112h can further encourage the rounded end portion 112e to rotate when pushed against the membrane rather than piercing the membrane and potentially the retina.

[0037] Inner ring 114 may include straight portions 114c, 114d extending from ends 114a, 114b, respectively. Straight portions 114c, 114d may intersect the longitudinal-transverse plane. Straight portions 114c, 114d may be offset from one another in the longitudinal-transverse plane, i.e., flare outwardly from one another as the distance from the distal end of outer tube 106 increases.

[0038] Straight portions 114c and 114d may be connected to each other by a rounded end portion 114e. Rounded end portion 114e may be: (a) formed to maintain a rounded shape in the absence of external forces; or (b) the result of bending inner ring 114 and securing ends 114a and 114b to inner tube 116. Rounded end portion 114e may be at the same angle as angle 112h relative to the longitudinal-transverse plane or at a different angle. In the absence of a deforming force, rounded end portion 114e may have an outer surface whose size in a plane of curvature (e.g., the longitudinal-transverse plane or a plane oriented at angle 112h relative to the longitudinal-transverse plane) is substantially equal to the size of the outer surface of rounded end portion 112e, the size of the inner surface of rounded end portion 112e, or smaller than the inner diameter of rounded end portion 112e. The flexibility of outer ring 112 and inner ring 114 enables nesting of outer ring 112 and inner ring 114 regardless of their size when undeformed.

[0039] In the illustrated embodiment, the straight portions 114c, 114d can have a reduced height and / or thickness relative to the straight portions 112c, 112d and the rounded end portion 114e, so that the inner ring 114 is more flexible than the outer ring 112 and so that no discontinuous flexible portion similar to the flexible portions 112f, 112g is formed between the straight portions 114c, 114d and the rounded end portion 114e. However, in other embodiments, the flexible portions are used in a similar manner. As discussed in more detail below, the outer ring 112 can be used to lift a flap in the membrane, which may require applying a certain degree of pressure on the membrane. In contrast, the inner ring 114 only needs to press the flap against the outer ring 112. Therefore, the inner ring 114 can be made more flexible to reduce the risk of puncture, while still having sufficient rigidity to press the flap against the outer ring 112.

[0040] refer to Figure 1B, one or both of the lower surfaces 132 and 134 of the rounded end portion 112e and the rounded end portion 114e can have a structure formed thereon to promote the clamping of the membrane. For example, the lower surfaces 132, 134 can have barbs 122 formed thereon. For the rounded end portion 112e, the barbs 122 can point towards the rounded end portion 114e, as indicated by arrows 136. In other words, the barbs 122 on the rounded end portion 114e are oriented so that the movement of the rounded end portion 112e relative to the membrane will be more resisted for the relative movement of the rounded end portion 112e toward the rounded end portion 114e than for the relative movement away from the rounded end portion 114e. In this way, the barbs 122 enhance the ability of the rounded end portion 112e to pull the membrane and lift the flap between the rounded end portions 112e, 114e. The barbs 122 may be tapered so that the resistance of the membrane to penetration by the barbs 122 increases with depth. This reduces the risk of the barbs 122 completely penetrating the membrane. In some applications, the tapered shape of the barbs 122 prevents the lower surface 132 of the rounded end portion 112e from actually contacting the membrane during use.

[0041] exist Figure 1B In some embodiments, the rounded end portion 114e has no barbs on the lower surface 134. In other embodiments, barbs 122 are included on the lower surface 134 of the rounded end portion 114e. In such embodiments, the barbs 122 can point in a direction opposite to the barbs 122 on the rounded end portion 112e, such that the barbs 122 enhance the ability of the rounded end portion 114e to push the membrane toward the rounded end portion 112e. Again, in other embodiments, no barbs are formed on the lower surface 134 of the rounded end portion 114e, such that the rounded end portion 114e is primarily or solely responsible for gripping the flap.

[0042] In some embodiments, the inner surface 142 of the rounded end portion 112e (the surface facing the rounded end portion 114e) and the outer surface 144 of the rounded end portion 114e (the surface facing the rounded end portion 112e) are textured, barbed, and coated with a clamping material (e.g., silicone) to resist sliding of the flap when it is grasped between the rounded end portion 112e and the rounded end portion 114e.

[0043] refer to Figure 2, various actuation mechanisms can be used to manually control the translation of the outer tube 106 and the inner rod 118. In some embodiments, the clamshell arms 110a, 110b can be replaced with a second slider 200 slidably mounted to the handle 102. In the illustrated embodiment, both sliders 108, 200 slide within a common slot 202 defined by the handle 102. Thus, one slider 108 can control actuation of the outer tube 106 and the other slider 200 can control actuation of the inner ring 114, or vice versa.

[0044] Figure 3 Example mechanisms are shown for coupling the slider 108 and clamshell arms 110a, 110b to the outer tube 106 and inner rod 118, or for coupling the slider 108 and slider 200 to the outer tube 106 and inner rod 118. The mechanisms shown are exemplary only and illustrate example relative movement of the components. However, the actual size and relative positions of the components may vary. Figure 3 For purposes of this disclosure, the "first actuator" and the "second actuator" refer to the slider 108 and the clamshell arms 110a, 110b. The "first actuator" and the "second actuator" may also refer to the slider 108 and the slider 200, or vice versa.

[0045] In the illustrated embodiment, the inner tube 116 is fixed relative to the handle 102. The outer tube 106 is slidable relative to the handle 102 and has a mounting structure 300 secured thereto. The mounting structure 300 is also slidable relative to the handle 102 and is coupled to the first actuator. The outer tube 106 defines a slot 302, and the inner tube 116 defines a slot 304. The mounting structure 306 is secured to the inner rod 118 and is slidable within the slots 302, 304. The mounting structure 306 is coupled to the second actuator.

[0046] Various alternatives to the illustrated configuration are possible. For example, the inner rod 118 can be fixed relative to the handle 102 , and the mounting structure 306 can be secured to the inner tube 116 , which can be slidable relative to the handle 102 .

[0047] In use, the first actuator can be moved in a first direction to move the outer tube 106 outward from the handle 102 and over the outer ring 112 and the inner ring 114. The first actuator can be moved in a second direction opposite to the first direction to move the outer tube 106 inward, thereby extending the outer ring 112 and the inner ring 114 from the distal end of the outer tube 106.

[0048] The first direction for the slider 108 or the slider 200 can be defined as movement 360 toward the distal end of the outer tube 106, and the second direction can be movement 370 of the slider 108 or the slider 200 away from the distal end of the outer tube 106. For the basket 110, the first direction can be defined as the expansion of the clamshell arms 110a, 110b (i.e., the release of pressure pushing against the clamshell arms 110a, 110b), and the second direction can be defined as the pressing of the clamshell arms 110a, 110b toward each other. The second actuator can be moved in the first direction to move the inner ring 114 toward the outer ring 112 to grasp the membrane flap. The second actuator can be moved in the second direction to move the inner ring 114 away from the outer ring 112. With outer ring 112 and inner tube 116 actuated by a second actuator, the second actuator may move in a first direction to move outer ring 112 away from the inner ring and in a second direction to move outer ring 112 toward inner ring 114 to grasp the flap.

[0049] Now refer to Figure 4A In preparation for lifting the flap, the outer ring 112 and the inner ring 114 can be positioned in the illustrated open configuration, wherein the gap 400 between the rounded end portion 112e and the rounded end portion 114e is many times the thickness of the membrane, for example, at least 10 times, 100 times, or 1000 times the thickness of the membrane. Figure 4B In some embodiments, straight portions 112c, 112d define a slot 402, and straight portions 114c, 114d define a protrusion 404 that can be inserted into slot 402. Protrusion 404 can slide within slot 402 for at least a portion of the range of motion of inner ring 114 (e.g., for a range of motion starting from when rounded end portion 114e presses against rounded end portion 112e). Protrusion 404 can be freely inserted into slot 402 or can resist removal (e.g., a slightly enlarged distal end). The positions of slot 402 and protrusion 404 can be reversed: slot 402 formed on straight portions 114c, 114d, and protrusion 404 formed on straight portions 112c, 112c.

[0050] The engagement of slots 402 with protrusions 404 can be used to maintain alignment of the rings during use. For example, this can prevent inner ring 114 from being positioned above outer ring 112 and failing to engage the membrane petals. However, using the flexibility of outer ring 112 and inner ring 114, both rings can be pressed against the membrane, ensuring that inner ring 114 will engage the petals when moved toward outer ring 112. Therefore, in some embodiments, slots 402 and protrusions 404 can be omitted.

[0051] refer to Figure 5A, the surgeon can translate the second actuator toward the distal end of the handle 102 (toward the outer tube 106) (e.g., compressing the clamshell arms 110a, 110b or translating the slider 200) to urge the inner ring 114 toward the outer ring 112 to achieve the illustrated closed configuration. It will be apparent that the rounded end portion 114e will nest within the rounded end portion 112e, thereby securely grasping the flap lifted by the rounded end portion 112e. When in the closed configuration, the spacing between the rounded end portion 114e and the rounded end portion 112e can be less than or equal to four, three, or two times the thickness of the membrane.

[0052] refer to Figure 5B , the outer tube 106 can be partially or completely extended over the outer ring 112 and the inner ring 114 at any point during use of the surgical instrument 100. The stiffness of the outer ring 112 and the inner ring 114 can be increased by extending the outer tube 106 and reducing the portion of the outer ring 112 and the inner ring 114 located outward from the outer tube 106. Likewise, where greater flexibility is desired, the outer tube 106 can be withdrawn to a point where more, possibly all, of the outer ring 112 and the inner ring 114 are exposed.

[0053] As described above, in preparation for inserting the outer tube 106 through the cannula, the outer tube 106 can be extended until: (a) the outer ring 112 and the inner ring 114 are completely located within the outer tube 106; or (b) the portion of the outer ring 112 and the inner ring 114 extending outward from the outer tube 106 is small enough to fit through the cannula (e.g., equal to or less than the outer diameter of the outer tube 106).

[0054] Now refer to Figure 6A During use, the lower surfaces 132, 134 of the rounded end portions 112e, 114e are pressed against a membrane 600 (e.g., an ILM or ERM) positioned on the retina 602. As shown, the barbs 122 can at least partially penetrate the ILM. The extent of the barbs 122 below the lower surface of the rounded end portions 112e, 114e can be less than the thickness of the ILM, such as less than 2 microns to 10 microns. For example, the barbs 122 can have a length from the lower surface outward between 0.8 microns and 8 microns. Figure 6B , the flap 604 can be lifted by pulling the rounded end portion 112e through the membrane 600, and the rounded end portion 114e can be pushed toward the rounded end portion 112e to securely grasp the flap 604. Figure 6C , the surgeon can then lift the surgical instrument 100 to tear off the membrane 600. Figure 7 , the surgeon can move the grasping structure 104 in a circular motion to peel a portion of the membrane 600 away from the retina 602.

[0055] Various alternatives to the illustrated method of use of surgical instrument 100 are possible. For example, inner ring 114 can be fixed relative to handle 102 as described above, and outer ring 112 can be actuated. Thus, outer ring 112 can be actuated to move rounded end portion 112e toward rounded end portion 114e, thereby both lifting flap 604 and capturing flap 604 between rounded end portion 112e and rounded end portion 114e in a single motion. In other methods of use, rounded end portion 112e is pulled through membrane 600 in the direction of rounded end portion 114e to lift flap 604 without reducing the distance between rounded end portion 112e and rounded end portion 114e. A second actuator is then used to pull rounded end portion 112e toward rounded end portion 114e, which further lifts flap 604 and captures flap 604 between rounded end portion 112e and rounded end portion 114e.

[0056] Figure 8A Another ophthalmic surgical instrument 800 is shown that includes a handle 802 that is sized and contoured to be grasped by the hand of a surgeon performing an ophthalmic surgical procedure, such as removing a retinal membrane, such as an ILM or ERM, from a patient's eye. A grasping structure 804 can extend from a distal end of an outer tube 806 connected to the handle 802. This proximal end of the outer tube 806 is connected to the handle 802. The handle 802 can have one or more manual control structures mounted thereto for manually actuating the grasping structure 804. Figure 8A In the embodiment of the present invention, the manual control structure includes a slide 808 and a deformable basket 810. The manual control structure shown is only exemplary, and other manual control structures and / or combinations of manual control structures may also be used (e.g., see Figure 9 ).

[0057] Figure 8AThe gripping structure 804 in FIG. 8 is embodied as an outer arm 812 and an inner arm 814. The outer arm 812 can be referred to as an outer gripping member of the gripping structure 804, and the inner arm 814 can be referred to as an inner gripping member of the gripping structure 804. The outer tube 806 can define a longitudinal direction 816a that is parallel to an axis of symmetry of the outer tube 806. The outer arm 812 and the inner arm 814 can include straight portions 812a, 814a that extend substantially (e.g., within 5 to 15 degrees) parallel to the longitudinal direction 816a. The outer arm 812 and the inner arm 814 are offset from one another along a transverse direction 816b that is substantially (e.g., within 5 degrees) parallel to the longitudinal direction 816a, which is defined as perpendicular to the longitudinal direction 816a. A vertical direction 816c can be defined as perpendicular to both the longitudinal direction 816a and the transverse direction 816b. The straight portions 812a, 814a may be implemented as hollow cylindrical tubes, solid cylindrical rods, or have some other solid or hollow cross-sectional shape in a plane perpendicular to the longitudinal direction 816a.

[0058] The straight portion 812a, 814a has a scraper 812b, 814b fastened to its far end. The scraper 812b, 814b generally extends perpendicular to the longitudinal direction 816a (e.g., within 15 degrees) and extends outward from the straight portion 812a, 814a. The scraper 812b, 814b can each have an arc shape, such as an elongated spoon shape. The scraper 812b, 814b can have an arc shape in a plane substantially (e.g., within 15 degrees) perpendicular to the longitudinal direction 816a and the transverse direction 816b. The scraper 812b, 814b can have an arc shape in a plane substantially (e.g., within 15 degrees) perpendicular to the longitudinal direction 816a and the vertical direction 816c. The scraper 812b, 814b can have an ellipsoid or any other three-dimensional curved shape. The scrapers 812b, 814b can have an arcuate shape on both the inner surface (facing the outer tube 806) and the outer surface (facing away from the outer tube 806). The scrapers 812b, 814b can be at least partially nested: a portion of the convex outer surface of the scraper 814b is positioned within the cavity defined by the concave inner surface of the scraper 812b. The scrapers 812b, 814b can be identical within manufacturing tolerances, or the scraper 812b can be made larger to better accommodate the scraper 814b when nested.

[0059] refer to Figure 8B, one or both of the scrapers 812b, 814b may include barbs 818. The barbs 818 of the scraper 812b may be oriented so that when the scraper 812b is moved in the direction that the concave surface of the scraper 812b is facing, the barbs 818 will capture the film more effectively than when it is moved across the film in the opposite direction. The barbs 818 of the scraper 814b may point in opposite directions. When the scraper 814b is moved in the direction that the concave surface of the scraper 814b is facing, the barbs 818 of the scraper 814b will capture the film less effectively than when it is moved across the film in the opposite direction.

[0060] The length of the barb 818 extending outward from the lower edge of the scraper 812b, 814b is less than the thickness of the film being stripped. For example, the film can have a thickness of 4 microns. The barb 818 can have a length between 1 micron and 3 microns from the lower edge of the scraper 812b, 814b.

[0061] The inner arm 814 and the outer arm 812 can be made of a highly flexible material such as Nitinol (nickel titanium alloy), spring steel, a polymer material, or other materials. The high flexibility allows the scrapers 812b, 814b to be elastically deformed so as to fit within the outer tube 806 and, when extended from the outer tube 806, to rebound outward in the transverse direction 816b to a distance greater than the outer diameter of the outer tube 806. For example, the scrapers 812b, 814b can extend outward from the longitudinal direction 816a in the transverse direction 816b by at least one, two, four, eight, or some other multiple of the outer tube diameter. Figure 8A As shown, in some implementations, both scrapers 812b, 814b extend outwardly from the outer tube 806 on only one side of a plane defined by the longitudinal direction 816a and the vertical direction 816c.

[0062] Figure 8B Further demonstrated the shape of scraper 812b, 814b.As shown in cross-sectional shape 822, scraper 812b, 814b has concave inner surface 834 and convex outer surface 826.Cross-sectional shape 822 can be limited with respect to the cross-sectional plane that is parallel to longitudinal direction 816a and vertical direction 816c.The concave inner surface 834 of scraper 812b and the convex outer surface 826 of scraper 814b can be texturized to promote clamping.Texturization can be any processing or the pattern of the clamping that improves film, such as due to the roughness that causes of the formation of such as processes such as polishing or grinding, regular peak and valley pattern, barb array or other texturizations increases.

[0063] Line 824 can be defined as the tangent line of scraper 812b, 814b at two points above and below concave inner surface 834. Line 824 can be used to understand the orientation of scraper 812b, 814b. Line 824 defines angle 828 relative to plane 830 parallel to longitudinal direction 816a and transverse direction 816b. Outer tube 806 can be inserted into the trocar cannula offset from the pupil of the patient's eye, and the film to be peeled off can be located directly behind the pupil. Therefore, longitudinal direction 816a can be at a non-parallel angle relative to the normal vector of the film at the point of contact with each scraper 812b, 814b. Angle 828 can be selected so that in use, line 824 is substantially (for example, within 15 degrees) parallel to the normal vector of the film at the contact point of scraper 812b, 814b and the film at cross-sectional plane 822. For example, angle 828 can be between 75 degrees and 105 degrees. This relationship between line 824 and the normal vector and contact point may exist along a substantial portion (eg, at least 80 percent) of the extent of the scrapers 812b, 814b in the lateral direction 816b.

[0064] refer to Figure 9 Various manual actuation mechanisms and / or control structures can be used to control the translation of one or both arms 812, 814. In some embodiments, the deformable basket 810 can be replaced with a second slider 900 slidably mounted to the handle 802. In the illustrated embodiment, both sliders 808, 900 slide within a common slot 902 defined by the handle 802. The slider 808, deformable basket 810, and slider 900 are exemplary only. Any actuation mechanism or structure known in the art, such as a button, can be used to control the movement of one or both arms 812, 814.

[0065] Figure 10 Example mechanisms are shown for coupling slide 808 and deformable basket 810 to arms 812, 814 or for coupling slide 808 and slide 900 to arms 812, 814. The mechanisms shown are exemplary only and illustrate example relative movement of the components. Further, the actual sizes and relative positions of the components may vary. Figure 10 For purposes of this disclosure, "first actuator" and "second actuator" may refer to slide 808 and deformable basket 810, or vice versa. "First actuator" and "second actuator" may also refer to slide 808 and slide 900, or vice versa.

[0066] In the illustrated embodiment, there are two slidable members 1000, 1002. The slidable members can be concentric tubes: the slidable member 1002 is positioned within the slidable member 1000. However, other arrangements are possible, such as the slidable members simply being positioned adjacent to each other within the outer tube 806 or within a cavity within the handle 802. The slidable member 1000 can be coupled to the outer arm 812, while the slidable member 1002 is coupled to the inner arm 814. However, the reverse arrangement is also possible.

[0067] The slidable member 1002 is coupled to a mounting structure 1004, which is coupled to the first actuator. Where the slidable member 1002 is positioned within a slidable member 1000 implemented as a tube, the slidable member 1000 can define a slot 1006 through which the mounting structure 1004 protrudes, and within which the mounting structure 1004 can slide along a range of motion along the longitudinal direction 816a. Where the slidable member 1002 is positioned within an outer tube 806, the outer tube 806 can define a slot 1008 through which the mounting structure 1004 protrudes, and along which the mounting structure 1004 has a range of motion along the longitudinal direction 816a.

[0068] The slidable member 1000 is coupled to a mounting structure 1010, which is coupled to the second actuator. With the slidable member 1000 positioned within the outer tube 806, the mounting structure 1010 can also protrude through the slot 1008 and have a range of motion within the slot 1008 along the longitudinal direction 816a. Alternatively, the mounting structure 1010 can protrude through a different slot.

[0069] 814b . Figure 11B, discussed below). The length of the slot 1006 can be selected to control the size of the gap. After the outer arm 812 is extended to extend the inner arm 814 to the point where the scrapers 812b, 814b are pressed together, the second actuator can be moved in a first direction. The first actuator, or both the first and second actuators, can then be moved in a second direction to pull the arms 812, 814 into the outer tube 806. In some implementations, when only the first actuator is used, the engagement of the scrapers 812b with the scrapers 814b and the friction between the slidable parts 1000, 1002 can be sufficient to push the inner arm 814 into the outer tube 806. In other implementations, the user can engage both the first and second actuators simultaneously when withdrawing the inner and outer arms 814, 812.

[0070] right Figure 10 An alternative embodiment is shown in which the outer arm 812 is fixed relative to the handle 802 and the outer tube 806 is slidable relative to the handle 802 and coupled to the first actuator. In use, the user will withdraw the outer tube 806 by moving the first actuator in the second direction, causing the scrapers 812b, 814b to extend from the distal end of the outer tube 806. After the petal is lifted with the scraper 812b, the second actuator can be moved in the first direction to press the scraper 814b against the scraper 812b. The first actuator can then be moved in the first direction to extend the outer tube 806 over the scrapers 812b, 814b.

[0071] refer to Figure 11A , after the outer tube 806 is inserted through the trocar cannula, the scraper 812b of the outer arm 812 can extend from the outer tube 806 and press against the membrane 1100. The straight portion 812a and the scraper 812b themselves can be sufficiently flexible so that pressure applied to the membrane 1100 will cause the lower edge of the scraper 812b to be substantially completely (e.g., at least 80 percent) in contact with the membrane 1100. The scraper 812b can then be scraped across the membrane 1100 to lift the flap 1102. Pulling the scraper 812b across the membrane 1100 can simply lift the flap 1102, or it can both lift the flap and tear off the membrane 1100.

[0072] refer to Figure 11B , the scraper 814b of the inner arm 814 can then be extended from the outer tube 806. It should be noted that the two scrapers 812b, 814b can be Figure 11A The scraping step is shown preceded by simultaneous extension, provided that the gap between the scrapers 812b, 814b along the longitudinal direction 816a is sufficient so that only the scraper 812b is in contact with the membrane 1100 during the scraping step.

[0073] refer to Figure 11C, the inner arm 814 can continue to extend from the outer tube 806 until the scraper 814b presses against the petal 1102 and the petal 1102 is clamped between the scrapers 812b, 814b. As the scraper 814b extends from the outer tube 806, the barbs 818 on the lower edge of the scraper 814b can press against the membrane 1100 and help further lift the petal 1102 until the scraper 814b presses the petal 1102 against the scraper 812b. Alternatively, the barbs 818 can be omitted from the scraper 814b.

[0074] refer to Figure 12 Once the flap 1102 is grasped between the scrapers 812b, 814b, the grasping structure 804 can be moved in a circular motion to peel a portion of the membrane 1100 away from the patient's retina 1200. The scrapers 812b, 814b can then be withdrawn within the outer tube 806, and the outer tube 806 can be withdrawn from the trocar cannula. Example Embodiments

[0075] Example 1: A method for peeling a membrane from the retina of a patient's eye, the method comprising: inserting the distal end of an outer tube into a cannula passed through the patient's eye; extending an outer ring and an inner ring from the outer tube; engaging the membrane with the outer ring to form a flap; and bringing the inner ring and the outer ring together so that the flap is captured between the inner ring and the outer ring.

[0076] Example 2: The method of Example 1, further comprising pulling the flap to effectively peel a portion of the membrane from the retina.

[0077] Embodiment 3: The method of embodiment 1, wherein the outer tube is mounted to a handle having an actuator mounted thereto and coupled to the inner ring, the method comprising moving the actuator to move the inner ring toward the outer ring.

[0078] Example 4: A method as described in Example 3, wherein: the actuator is a first actuator and a second actuator is mounted to the handle; the outer tube is slidably mounted to the handle and connected to the second actuator; and extending the outer ring and the inner ring includes moving the second actuator to retract the outer tube.

[0079] Embodiment 5: The method of embodiment 1, wherein the width of the outer ring and the inner ring when extended from the outer tube is at least four times the outer diameter of the outer tube.

[0080] Example 6: The method of Example 5 further comprises withdrawing the outer ring and the inner ring into the outer tube while only elastically deforming the outer ring and the inner ring.

[0081] Example 7: The method of Example 6, wherein the outer ring and the inner ring each comprise nitinol.

[0082] Example 8: An ophthalmic surgical instrument for peeling off a retinal membrane, the ophthalmic surgical instrument comprising: a handle; an actuator mounted on the handle; an outer tube having a proximal end mounted to the handle; an outer ring extending outward from the distal end of the outer tube; and an inner ring extending outward from the distal end of the outer tube and positioned within the outer ring, the actuator being configured to move one of the inner ring and the outer ring so that the inner ring and the outer ring are brought together to grasp the retinal membrane.

[0083] Example 9: The ophthalmic surgical instrument of Example 8, wherein the actuator is configured to move the inner ring toward the outer ring in response to movement of the actuator in the first direction.

[0084] Example 10: The ophthalmic surgical instrument of Example 9, wherein the actuator is configured to move the inner ring away from the outer ring in response to movement of the actuator in a second direction opposite to the first direction.

[0085] Example 11: The ophthalmic surgical instrument of Example 8, wherein the width of the outer ring and the inner ring is at least twice the outer diameter of the outer tube.

[0086] Example 12: The ophthalmic surgical instrument of Example 11, wherein the width of the outer ring and the inner ring is at least four times the outer diameter of the outer tube.

[0087] Example 13: The ophthalmic surgical instrument of Example 12, wherein the outer ring and the inner ring are configured to be sufficiently elastically deformed to fit within the outer tube.

[0088] Example 14: The ophthalmic surgical instrument of Example 12, wherein the outer ring and the inner ring each comprise nitinol.

[0089] Example 15: The ophthalmic surgical instrument of Example 8, wherein the first surface of the outer ring includes first tapered barbs configured to grip a membrane on the retina of the patient's eye and having a length outward from the first surface that is less than the thickness of the membrane.

[0090] Example 16: The ophthalmic surgical instrument of Example 15, wherein the length is between 0.8 microns and 8 microns.

[0091] Example 17: The ophthalmic surgical instrument of Example 16, wherein the second surface of the inner ring positioned to engage the membrane when the first surface is pressed against the retina does not have barbs formed thereon.

[0092] Example 18: An ophthalmic surgical instrument as described in Example 8, wherein one of the following: the outer ring defines one or more slots, and the inner ring defines one or more protrusions positioned within the one or more slots; and the inner ring defines one or more slots, and the outer ring defines one or more protrusions positioned within the one or more slots.

[0093] Example 19: The ophthalmic surgical instrument of Example 8, wherein the outer ring defines an end portion coupled to the distal end of the outer tube by flexible portions having greater flexibility than the end portion.

[0094] Example 20: An ophthalmic surgical instrument as described in Example 8, wherein: the actuator is a first actuator; the ophthalmic surgical instrument further includes a second actuator connected to the outer tube; and the outer tube is slidable relative to the handle, the outer ring and the inner ring.

[0095] Example 21: The ophthalmic surgical instrument of Example 20, further comprising an inner tube positioned within the outer tube, the inner tube being fixed relative to the handle, and the outer ring being fastened to the inner tube.

[0096] Example 22: The ophthalmic surgical instrument of Example 21, further comprising an inner rod positioned within the inner tube, the inner rod coupled to the first actuator, and the inner ring secured to the inner rod.

[0097] Example 23: A method for peeling a membrane from the retina of a patient's eye, the method comprising: inserting the distal end of an outer tube into a cannula passed through the patient's eye, the outer tube being mounted to a handle; extending an outer arm from the outer tube, the outer arm having an outer scraper secured thereto; engaging the membrane with the outer scraper to form a flap; extending an inner arm from the outer tube, the inner arm having an inner scraper secured thereto; and pressing the inner scraper toward the outer scraper so that the flap is captured between the inner scraper and the outer scraper.

[0098] Example 24: The method of Example 23, wherein the inner arm, outer arm, inner scraper, and outer scraper each comprise nitinol.

[0099] Embodiment 25: The method of Embodiment 23, wherein the outer scraper defines a concave surface and the inner scraper defines a convex surface, the method further comprising capturing the petal between the concave surface and the convex surface.

[0100] Embodiment 26: The method of Embodiment 23, wherein engaging the membrane with the outer scraper to form the petal comprises engaging the membrane with barbs formed on an edge of the outer scraper.

[0101] Embodiment 27: The method of Embodiment 26, wherein the barbs are oriented to pull the film toward the inner scraper.

[0102] Embodiment 28: The method of Embodiment 26, wherein the barbs have a length outward from the edge that is less than the thickness of the film.

[0103] Example 29: An ophthalmic surgical instrument for peeling a retinal membrane, the ophthalmic surgical instrument comprising: a handle; a first actuator mounted on the handle; a second actuator mounted on the handle; an outer tube having a proximal end mounted to the handle; an outer arm having an outer scraper fastened thereto; and an inner arm having an inner scraper fastened thereto; wherein the first actuator is configured to control extension of the outer arm from the outer tube, and the second actuator is configured to control movement of the inner arm relative to the outer arm.

[0104] Example 30: The ophthalmic surgical instrument of Example 29, wherein the first actuator is coupled to the outer arm and the second actuator is coupled to the inner arm.

[0105] Example 31: The ophthalmic surgical instrument of Example 29, wherein the outer scraper defines a concave surface and the inner scraper defines a convex surface positioned to press against the concave surface.

[0106] Example 32: The ophthalmic surgical instrument of Example 31, wherein at least one of the concave surface and the convex surface is textured.

[0107] Example 33: The ophthalmic surgical instrument of Example 29, wherein the outer scraper has barbs formed on an edge thereof.

[0108] Example 34: The ophthalmic surgical instrument of Example 33, wherein the barbs are oriented to pull the membrane of the retina toward the inner scraper.

[0109] Example 35: An ophthalmic surgical instrument as described in Example 33, wherein the barbs have a length from the edge outward that is less than the thickness of the membrane of the retina.

[0110] Example 36: An ophthalmic surgical instrument as described in Example 35, wherein the length is between 1 micron and 3 microns.

[0111] Example 37: An ophthalmic surgical instrument as described in Example 29, wherein: the outer tube 106 defines a longitudinal direction, which is parallel to the axis of symmetry of the outer tube 106; and the outer scraper extends outward beyond the outer diameter of the outer tube in a transverse direction, which is perpendicular to the longitudinal direction.

[0112] Example 38: The ophthalmic surgical instrument of Example 37, wherein the outer scraper and the inner scraper extend outward in the lateral direction by at least twice the outer diameter of the outer tube.

[0113] Example 39: The ophthalmic surgical instrument of Example 29, wherein the outer arm, the inner arm, the outer scraper, and the inner scraper are made of Nitinol.

[0114] Example 40: A method for peeling a membrane from the retina of a patient's eye, the method comprising: inserting the distal end of an outer tube into a cannula passed through the patient's eye, the outer tube being mounted to a handle; extending an outer arm from the outer tube, the outer arm having an outer scraper secured thereto; engaging the membrane with the outer scraper to form a flap; extending an inner arm from the outer tube, the inner arm having an inner scraper secured thereto; and pressing the inner scraper toward the outer scraper so that the flap is captured between the inner scraper and the outer scraper.

[0115] Example 41: The method of Example 40, further comprising pulling the flap to effectively peel a portion of the membrane from the retina.

[0116] Example 42: A method as described in Example 40, wherein: the first actuator and the second actuator are mounted to the handle, the first actuator is connected to the outer arm, and the second actuator is connected to the inner arm; extending the outer arm from the outer tube includes moving the first actuator; and extending the inner arm from the outer tube includes moving the second actuator.

[0117] Embodiment 43: The method of Embodiment 40, wherein the outer scraper and the inner scraper extend outward from the axis of symmetry of the outer tube by at least twice the diameter of the outer tube.

[0118] The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but are to be given the full scope consistent with the language of the claims.

Claims

1. An ophthalmic surgical instrument for peeling off a retinal membrane, the ophthalmic surgical instrument comprising: handle; at least one actuator mounted on the handle; an outer tube having a proximal end mounted to the handle; a flexible outer gripping member extending or configured to extend outwardly from the distal end of the outer tube; as well as a flexible inner grasping member extending or configured to extend outwardly from the distal end of the outer tube, wherein the at least one actuator is configured to move at least one of the outer grasping member or the inner grasping member relative to the other such that the inner and outer grasping members are brought together to grasp a membrane of the retina.

2. The ophthalmic surgical instrument of claim 1, wherein: The flexible outer gripping member includes an outer ring extending outwardly from a distal end of the outer tube; and The flexible inner gripping member includes an inner ring extending outwardly from the distal end of the outer tube and positioned within the outer ring.

3. The ophthalmic surgical instrument according to claim 2, wherein: The at least one actuator is configured to move the inner ring toward the outer ring in response to movement of the at least one actuator along a first direction, and wherein the at least one actuator is further configured to move the inner ring away from the outer ring in response to movement of the at least one actuator along a second direction opposite to the first direction.

4. The ophthalmic surgical instrument according to claim 2, wherein: The width of the outer ring and the inner ring is at least twice the outer diameter of the outer tube.

5. The ophthalmic surgical instrument according to claim 4, wherein: The outer ring and the inner ring are configured to be sufficiently elastically deformed to fit within the outer tube.

6. The ophthalmic surgical instrument according to claim 4, wherein: The outer ring and the inner ring each comprise Nitinol.

7. The ophthalmic surgical instrument according to claim 2, wherein: The first surface of the outer ring includes a first tapered barb configured to grip a membrane on the retina of a patient's eye, the first tapered barb having a length outward from the first surface that is less than a thickness of the membrane.

8. The ophthalmic surgical instrument according to claim 7, wherein: The second surface of the inner ring, positioned to engage the membrane when the first surface is pressed against the retina, does not have barbs formed thereon.

9. The ophthalmic surgical instrument of claim 1 , wherein: The flexible outer gripping member includes an outer arm having an outer scraper secured thereto; The flexible inner gripping member includes an inner arm having an inner scraper secured thereto; and The at least one actuator includes a first actuator and a second actuator mounted on the handle, wherein the first actuator is configured to control extension of the outer arm from the outer tube and the second actuator is configured to control movement of the inner arm relative to the outer arm.

10. The ophthalmic surgical instrument according to claim 9, wherein: The outer scraper defines a concave surface and the inner scraper defines a convex surface positioned to bear against the concave surface.

11. The ophthalmic surgical instrument according to claim 10, wherein: At least one of the concave surface and the convex surface is textured.

12. The ophthalmic surgical instrument according to claim 9, wherein: The outer scraper has barbs formed on an edge thereof.

13. The ophthalmic surgical instrument according to claim 12, wherein: The barbs are oriented to pull the membrane of the retina toward the internal scraper.

14. The ophthalmic surgical instrument according to claim 12, wherein: The barbs have a length outward from the edge that is less than the thickness of the membrane of the retina.

15. The ophthalmic surgical instrument of claim 9, wherein: The outer tube defines a longitudinal direction that is parallel to an axis of symmetry of the outer tube; and The outer scraper and the inner scraper extend outwardly beyond the outer diameter of the outer tube in a transverse direction, the transverse direction being perpendicular to the longitudinal direction.

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