Gripping structure for membrane removal

Abstract

An ophthalmic surgical instrument for peeling a retinal membrane includes a handle and an actuator mounted on the handle. An outer tube is mounted on the handle, and an inner rod extends into the outer tube. A gripping structure is fixed to a distal end of the inner rod and has a first polymer arm and a second polymer arm fixed to the inner rod. Each of the first polymer arm and the second polymer arm has a distal end angled to conform to the retinal membrane. The actuator is configured to control the relative position of the inner rod and the outer tube to extend the gripping structure out of the outer tube and to withdraw the gripping structure from within the outer tube.

Description

[Background technology]

[0001] The internal limiting membrane (ILM) is a thin, transparent membrane located between the vitreous and retina of the eye. The ILM plays a role during eye development but is not necessary for proper function of the adult eye. The ILM pulls on the retina, causing conditions such as macular holes, macular atrophy, vitreomacular traction syndrome, diabetic macular edema, and cystoid macular edema, which are secondary to inflammation or venous occlusive disease and other conditions. An epiretinal membrane (ERM) is a membrane that can form on the retina in response to damage to the retina, such as from posterior vitreous detachment.

[0002] The ILM or ERM may need to be detached from the retina to prevent damage to the retina. Peeling the ILM or ERM may also be necessary in preparation for a surgical procedure to be performed on the retina. To detach the ILM or ERM, a surgical instrument is inserted through a cannula in the patient's eye. Forceps or a specialized scraper extend from the instrument and are used to lift a flap of the ILM or ERM. The flap is then grasped by the forceps, and the ILM or ERM is detached from the retina using a circular motion. However, if excessive force is applied to the forceps, the retina may be punctured.

[0003] Therefore, reducing the risk of retinal damage resulting from membrane detachment would be an advancement in the art. Summary of the Invention [Means for solving the problem]

[0004] SUMMARY The present disclosure generally relates to a film peeling tool that includes a gripping structure having flexible polymer arms with angled end faces.

[0005] An ophthalmic surgical instrument for peeling a retinal membrane includes a handle and an actuator mounted on the handle. An outer tube is attached to the handle and has a proximal end defining a longitudinal direction. An inner rod extends into the outer tube. A gripping structure is fixed to the distal end of the inner rod. The gripping structure includes a first polymer arm and a second polymer arm fixed to the inner rod and biased outward from each other along a transverse direction perpendicular to the longitudinal direction. Each of the first polymer arm and the second polymer arm has a distal end at an angle of 0 to 90 degrees (e.g., 10 to 60 degrees) relative to a direction perpendicular to the longitudinal and transverse directions. The actuator is configured to extend the gripping structure from the outer tube and control the relative position of the inner rod and the outer tube to withdraw the gripping structure into the outer tube.

[0006] The following description and the annexed drawings set forth in detail certain illustrative features of the one or more embodiments.

[0007] The accompanying drawings depict certain aspects of one or more embodiments and therefore should not be considered as limiting the scope of the disclosure. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an isometric view of a surgical instrument having a grasping structure including flexible polymer arms, in accordance with certain embodiments. [Figure 2A] FIG. 1 illustrates an isometric view of a flexible polymer arm, according to certain embodiments. [Figure 2B] 10A-10C are isometric views of alternative shapes for flexible polymer arms, according to certain embodiments. [Figure 2C] FIG. 10 is an isometric view illustrating texturing on the inner surface of a flexible polymer arm, according to certain embodiments. [Figure 2D] FIG. 10 is an isometric view showing a flexible polymer arm molded onto an extension of an inner tube, according to certain embodiments. [Figure 3] FIG. 10 is an isometric view of an alternative embodiment of an actuator for controlling a gripping structure, in accordance with certain embodiments. [Figure 4A] FIG. 10 is an isometric view showing a flexible polymer arm in an open configuration, according to certain embodiments. [Figure 4B] FIG. 1 is an isometric view showing a flexible polymer arm in a closed configuration, according to certain embodiments. [Figure 5A] 10A-10C are side cross-sectional views illustrating peeling of an ILM using a gripping structure, according to certain embodiments. [Figure 5B] 10A-10C are side cross-sectional views illustrating peeling of an ILM using a gripping structure, according to certain embodiments. [Figure 5C] 10A-10C are side cross-sectional views illustrating peeling of an ILM using a gripping structure, according to certain embodiments. [Figure 6] FIG. 10 is an isometric view showing an ILM being peeled away using a gripping structure, according to certain embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0009] To facilitate understanding, the same reference numerals will be used, whenever possible, to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0010] Aspects of the present disclosure provide a surgical instrument including a grasping structure with flexible polymer arms for peeling a membrane from a patient's retina. Note 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 away from the patient's body, or, for example, the end proximal to the handle of a surgical instrument.

[0011] FIG. 1 illustrates a surgical instrument 100 according to certain embodiments of the present disclosure. The surgical instrument includes a handle 102 sized and contoured to be grasped by the hand of a surgeon performing an ophthalmic surgical procedure, including, for example, peeling a membrane, such as an internal limiting membrane (ILM) or an epiretinal membrane (ERM), from the retina of a patient's eye. A gripping structure 104 can extend from a distal end of an outer tube 106 connected to the handle 102, the proximal end of which is connected to the handle 102. The handle 102 can have one or more manual control structures attached thereto. In the embodiment of FIG. 1, the manual control structure includes a deformable basket 110. The manual control structure shown is exemplary only, and other manual control structures can also be used (see, for example, FIG. 3).

[0012] 1, the grasping structure 104 is embodied as a forceps including a first flexible polymer arm 112 and a second flexible polymer arm 114. The first flexible polymer arm 112 and the second flexible polymer arm 114 are connected to an inner rod 116 that is slidably positioned within the outer tube 106. The inner rod 116 may be implemented as a solid rod or, alternatively, as a hollow tube.

[0013] In the illustrated embodiment, the first flexible polymer arm 112 has an end 112a that is fastened to the inner rod 116 either directly or via an intermediate arm 116a. The second flexible polymer arm 114 has an end 114a that is fastened to the inner rod 116 either directly or via an intermediate arm 116b. The outer tube 106, inner rod 116, and arms 116a, 116b may be made of nitinol, stainless steel, spring steel, a rigid polymer, or other materials. In some embodiments, the flexible polymer arms may be made of a softer material (e.g., silicone) than the tube. The arms 116a, 116b may be fixed to the inner rod 116 or may be monolithically formed with the inner rod 116.

[0014] In some embodiments, the deformable basket 110 of the handle 102 is coupled to the outer tube 106. In use, the outer tube 106 may extend over the first flexible polymer arm 112 and the second flexible polymer arm 114 of the gripping structure 104, such as while the outer tube 106 is being inserted into or withdrawn from a cannula (e.g., called a trocar cannula) inserted into a patient's eye. Upon releasing compression of the deformable basket 110, the outer tube 106 may then be withdrawn or retracted, thereby extending the inner rod 116 and the gripping structure 104 relative to the outer tube 106. Upon compression of the deformable basket 110, the outer tube 106 may extend over the inner rod 116, thereby retracting the inner rod 116 relative to the outer tube 106 and gripping the gripping structure 104. In other embodiments, the deformable basket 110 is coupled to the inner rod 116, and the outer tube 106 is fixed relative to the handle 102. Thus, extension of the inner rod 116 and gripping structure 104 may be achieved by compressing the deformable basket 110, while release of compression of the deformable basket 110 causes the inner rod 116 and gripping structure 104 to retract into the outer tube 106.

[0015] The first flexible polymer arm 112 and the second flexible polymer arm 114 are biased outwardly from one another upon extending from the outer tube 106. The outer tube 106 can extend against the inner rod 116 to press the first flexible polymer arm 112 and the second flexible polymer arm 114 together and grip a membrane, such as an ILM or ERM.

[0016] The first flexible polymer arm 112 and the second flexible polymer arm 114 can be made of a highly flexible material, such as a thermoplastic elastomer, silicone, or other elastic material. The thermoplastic elastomer can be selected to provide sufficient rigidity to grip the membrane while being soft enough to reduce the risk of puncturing the retina. For example, the thermoplastic elastomer can have a hardness of about 10 to about 90 Shore A, e.g., about 20 to about 80 Shore A, e.g., about 30 to about 60 Shore A. The flexibility of the flexible material forming the flexible polymer arms 112, 114 can be selected in combination with the stiffness of the arms 116a, 116b around which the flexible polymer arms 112, 114 are molded, such that the arms 116a, 116b can be made correspondingly stiffer to enable gripping of the membrane. The arms 116 a, 116 b, if used, may likewise be made of a highly flexible material such as, for example, steel, stainless steel, spring steel, nitinol, or a polymer. The high flexibility allows the first and second flexible polymer arms 112, 114, and arms 116 a, 116 b, in use, to elastically deform to fit within the outer tube 106 and expand to a size much wider than the outer diameter of the outer tube 106 when extending from the outer tube 106. In certain embodiments, for example, the first and second flexible polymer arms 112, 114, and arms 116 a, 116 b, in use, may expand to at least 2, 4, 8, or 16 times the outer diameter of the outer tube 106.

[0017] The outer tube 106 defines a longitudinal direction 120a that is parallel to and collinear with the axis of symmetry of the outer tube 106. The axis of symmetry of the inner rod 116 is substantially collinear with the longitudinal direction 120a (e.g., within 0.5 mm (millimeters)) and substantially parallel to the longitudinal direction 120a (e.g., within 5 degrees). The transverse direction 120b may also be defined as perpendicular to the longitudinal direction 120a. The vertical direction 120c may be defined as perpendicular to the longitudinal direction 120a and the transverse direction 120b.

[0018] 2A and 2B, the flexible polymer arms 112, 114 can have a generally quadrilateral cross-section including surfaces 112b, 114b and surfaces 112c, 114c that are substantially parallel (e.g., within 5 degrees) to the longitudinal direction 120a and the transverse direction 120b ("longitudinal cross-section"). End surfaces 112d, 114d extend between surfaces 112b, 114b and 112c, 114c of the flexible polymer arms 112, 114, respectively. In the embodiment of FIG. 2A, surfaces 112d, 114d are substantially parallel (e.g., within 5 degrees) to the vertical direction 120c. 2B, surfaces 112d, 114d are at an angle relative to vertical 120c, for example, between 10° and 60°, between 20° and 50°, between 30° and 45°, or between 0° and 90°. Flexible polymer arms 112, 114 may also include a grasping platform, such as the 705.43, 705.44, or 705.45 ILM forceps from ALCON, or the MAXGRIP 705.13 forceps from ALCON.

[0019] Inner surfaces 112f, 114f and outer surfaces 112g, 114g extend between surfaces 112b, 114b and 112c, 114c of each flexible polymer arm 112, 114. In certain embodiments, inner surfaces 112f, 114f and / or outer surfaces 112g, 114g may be curved in the longitudinal cross-section and parallel to the vertical direction 120c. Inner surfaces 112f, 114f are generally oriented opposite one another and offset from one another in the transverse direction 120b as the gripping structure 104 extends from the outer tube 106.

[0020] The length of the flexible polymer arms 112, 114 between the ends 112 a, 114 a and the end faces 112 d, 114 d, and the flexibility of the material used to form the flexible polymer arms 112, 114, can be selected to allow the flexible polymer arms 112, 114 to deform when placed in contact with the retina or a patient's eye, thereby reducing the risk of puncturing the retina, while still providing sufficient rigidity to grip the membrane. The flexibility of the flexible polymer arms 112, 114 further allows them to bend, twist, or otherwise deform, allowing the end faces 112 d, 114 d to lay flat on the membrane.

[0021] The angle of the end faces 112d, 114d in the embodiment of FIG. 2B may be selected to facilitate flattening of the end faces 112d, 114d against the retina. In use, the outer tube 106 is inserted through a trocar cannula offset from the pupil, while the membrane is positioned just behind the pupil, requiring the outer tube 106 to be angled relative to the membrane at the point of contact between the gripping structure 104 and the membrane. Thus, the angled orientation of the end faces 112d, 114d may compensate for the angle of the outer tube 106 and facilitate flattening of the end faces 112d, 114d on the membrane.

[0022] 2A and 2B are exemplary only. Other shapes, including rounded shapes rather than quadrilaterals, may be used. For example, circular, oval, elliptical, or other cross-sectional shapes may be used, with the distal end surfaces of such shapes being flat or angled as described above relative to end faces 112d, 114d.

[0023] 2C , the inner surfaces 112f, 114f of one or both of the first flexible polymer arm 112 and the second flexible polymer arm 114 may have texture formed thereon to facilitate gripping of a membrane. For example, the inner surfaces 112f, 114f may have grooves 122 formed thereon. In the illustrated embodiment, the grooves 122 are oriented parallel to the vertical direction 120c, although grooves having other orientations may additionally or alternatively be used. In this manner, the grooves 122 enhance the ability of the inner surfaces 112f, 114f to grip a raised flap between the end surfaces 112d, 114d. In other embodiments, the texturing may include, but is not limited to, bumps, ridges, knurling, or other types of texturing.

[0024] 2D , the flexible polymer arms 112, 114 may be formed on an extension 150 of the material of the inner rod 116, such as, for example, arms 116a, 116b. In one embodiment, an adhesive is applied to the outer surface of the extension 150 before the material of the flexible polymer arms 112, 114 is molded onto the extension 150. The material of the extension 150 may be the same material as the inner rod 116, including nitinol, stainless steel, spring steel, a rigid polymer, or other material. The extension 150 may be a rectangular prism or a cylinder. In certain embodiments, the extension may have a textured finish to facilitate bonding with the flexible polymer arms 112, 114. The extension 150 extends from the distal end of the inner rod 116, such as, for example, arms 116a, 116b. The material of the flexible polymer arms 112, 114 extends over the extension 150 such that the distal end 151 of the extension 150 is within the material of the flexible polymer arms 112, 114 and does not extend through the flexible polymer arms 112, 114. Stated another way, a portion of the flexible polymer arms 112, 114 extends in the longitudinal direction 120a beyond the extension 150. The extension 150 may have the same flexibility as the flexible polymer arms 112, 114, or may be more or less flexible.

[0025] 3 , various actuation mechanisms can be used to control the translation of the outer tube 106 and the inner rod 116. In some embodiments, the deformable basket 110 can be replaced with a slider 200 slidably attached to the handle 102. In the illustrated embodiment, the slider 200 slides within a slot 202 defined by the handle 102. In certain embodiments, the slider 200 is coupled to the outer tube 106 and the inner rod 116 is coupled to the handle 102, such that the inner tube is fixed relative to the handle 102, and movement of the slider 200 moves the outer tube 106 on the inner rod 116. In certain embodiments, the slider 200 is coupled to the inner rod 116 and the outer tube 106 is coupled to the handle 102, such that the outer tube 106 is fixed relative to the handle 102, and movement of the slider 200 moves the inner rod 116 within the outer tube 106.

[0026] Referring now to FIG. 4A, in preparation for lifting the flap during a procedure, the first flexible polymer arm 112 and the second flexible polymer arm 114 can be positioned in the illustrated "open" configuration, with a gap 400 between the end faces 112d and 114d that is many times larger than the thickness of the membrane (e.g., at least 10, 100, or 1000 times the thickness of the membrane).

[0027] 4B , at any point during use of the surgical instrument 100, the outer tube 106 can be extended partially or fully over the first and second flexible polymer arms 112, 114, or over the arms 116a, 116b, to form a “closed” position. The stiffness of the first and second flexible polymer arms 112, 114 can be increased by extending the outer tube 106 and reducing the portion of the first and second flexible polymer arms 112, 114 positioned outward from the outer tube 106. Similarly, if more flexibility is desired, the outer tube 106 can be retracted to the point where more of the first and second flexible polymer arms 112, 114 are exposed, potentially entirely. Similarly, the amount of arms 116a, 116b extending from outer tube 106 can be controlled to control the stiffness of the combined flexible polymer arms 112, 114 and arms 116a, 116b.

[0028] As described above, in preparation for inserting the outer tube 106 into a trocar cannula positioned at an incision in the eye, the outer tube 106 may be extended until either (a) the first flexible polymer arm 112 and the second flexible polymer arm 114 are positioned completely within the outer tube 106, or (b) the portions of the first flexible polymer arm 112 and the second flexible polymer arm 114 extending outward from the outer tube 106 are small enough to fit through the cannula (e.g., equal to or less than the outer diameter of the outer tube 106).

[0029] In the embodiment shown, the forceps (flexible polymer arms 112 and 114 of the forceps) are slightly curved inward, and the end faces 112d, 114d are angled so that the end faces 112d, 114d meet one another when the forceps are closed. Other embodiments may include forceps with different shapes and / or different angles for the end faces 112d, 114d. For example, in certain embodiments, the flexible polymer arms 112 and 114 may not curve inward, the flexible polymer arms 112 and 114 may curve outward, or the flexible polymer arms 112 and 114 may be straight or substantially straight.

[0030] Referring to FIG. 5A, during use, the undersides of the end faces 112d, 114d are pressed downward against a membrane 500 (e.g., an ILM or ERM) positioned over the retina 502. Referring to FIG. 5B, the flap 504 can be lifted by pulling the end faces 112d, 114d toward each other across the membrane 500 to firmly grasp the flap 504. Referring to FIG. 5C, the surgeon can then lift the surgical instrument 100 away from the retina 502 to tear the membrane 500. Referring to FIG. 6, the surgeon can move the gripping structure 104 in a circular motion to peel a portion of the membrane 500 from the retina 502.

[0031] The foregoing description is provided to enable those 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 accorded the full scope consistent with the language of the claims.

Claims

1. An ophthalmic surgical instrument for peeling off a retinal membrane, comprising: The handle and an actuator attached to the handle; an outer tube having a proximal end attached to the handle and defining a longitudinal axis; an inner rod extending within the outer tube; a gripping structure secured to a distal end of the inner rod, the gripping structure comprising: a gripping structure comprising first and second polymer arms secured to the inner rod and biased outwardly toward one another along a transverse direction perpendicular to the longitudinal direction, each of the first and second polymer arms having a distal end at an angle between 0 and 90 degrees relative to a normal perpendicular to the longitudinal and transverse directions; Equipped with An ophthalmic surgical instrument, wherein the actuator is configured to control the relative position of the inner rod and the outer tube to extend the gripping structure out of the outer tube and to withdraw the gripping structure within the outer tube.

2. The ophthalmic surgical instrument of claim 1 , wherein the inner rod is formed of a first material and the first polymer arm and the second polymer arm are formed of a second material different from the first material.

3. The ophthalmic surgical instrument of claim 2 , wherein the second material is formed over the first material.

4. The ophthalmic surgical instrument of claim 2 , wherein the first material is steel or nitinol.

5. The ophthalmic surgical instrument of claim 2 , wherein the second material is a thermoplastic elastomer.

6. The ophthalmic surgical instrument of claim 5, wherein the thermoplastic elastomer has a hardness of 10-90 Shore A.

7. 3. The ophthalmic surgical instrument of claim 2, further comprising a first arm formed on the inner rod and a second arm formed on the inner rod, the first arm and the second arm comprising the first material, the first polymer arm secured to the first arm, and the second polymer arm secured to the second arm.

8. the first arm has a first extension formed thereon, and the first polymer arm is molded onto the first extension; The ophthalmic surgical instrument of claim 7 , wherein the second arm has a second extension formed therein, and the second polymer arm is molded over the second extension.

9. The ophthalmic surgical instrument of claim 1 , wherein the first polymer arm and the second polymer arm are configured to elastically deform sufficiently to fit within the outer tube.

10. The ophthalmic surgical instrument of claim 1 , wherein at least one of the first polymer arm and the second polymer arm is textured to improve gripping of a membrane on a retina of a patient's eye.

11. The ophthalmic surgical instrument of claim 1 , wherein the inner rod is fixed relative to the handle and the outer tube is fixed relative to the actuator.

12. 1. A method for detaching a membrane from a retina of a patient's eye, said method comprising: inserting a distal end of an outer tube through a cannula in the patient's eye; extending a gripping structure longitudinally from the outer tube, the gripping structure having first and second polymer arms secured to the inner rod and biased outwardly from each other along a transverse direction perpendicular to the longitudinal direction, the first and second polymer arms each having a distal end at an angle between 0 and 90 degrees relative to a perpendicular direction perpendicular to the longitudinal and transverse directions; pressing the distal end of the first polymer arm and the distal end of the second polymer arm against the membrane; and withdrawing the gripping structure at least partially into the outer tube to form a flap of the membrane and grip the flap between the first polymer arm and the second polymer arm, thereby urging the first polymer arm and the second polymer arm together.

13. 13. The method of claim 12, further comprising pulling the flap effective to detach a portion of the membrane from the retina.

14. 13. The method of claim 12, wherein the outer tube is attached to a handle having an actuator attached to the handle and coupled to the outer tube, the method comprising moving the actuator to extend the gripping structure from the outer tube and retract the gripping structure into the outer tube.

15. The method of claim 12 , wherein the inner rod comprises nitinol and the first and second polymer arms comprise a thermoplastic elastomer.

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