Patent Publication Number: US-2023157871-A1

Title: Tissue graft fixture

Description:
PRIORITY CLAIM 
     This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/052,245, filed Jul. 15, 2020, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This document pertains generally, but not by way of limitation, to a device for processing and manipulating a membrane. 
     BACKGROUND 
     One example of a debilitating eye disease is known as age-related macular degeneration (AMD). AMD typically causes blurred and/or impaired central vision and is a leading cause of blindness. Treatment options are limited and include drug therapy. Future stem cell therapeutic options are being studied. Treatment outcomes often fail, and the degeneration progresses despite therapy. 
     SUMMARY 
     An example of a surgical treatment includes either translocation surgery, a choroid patch graft, or stem cell construct, any may use autologous tissue to regenerate the macula. Current procedures are complicated by the limited ability to translocate healthy tissue and the elasticity and fragility of donor tissue. Choroid tissue is elastic, contracts, and is easily damaged during surgical manipulation for either of these procedures. 
     Approaches to overcome challenges associated with macular translocation include U.S. Pat. No. 10,278,808 which refers to a surgical support structure and U.S. Pat. No. 9,539,082 which refers to a tissue support structure. 
     Persistent challenges remain. For example, proper placement of a support structure is complicated by the challenging intraocular working environment. In addition, the translocation procedure requires the support structure be gently excised and moved to a new location. During these microsurgical manipulations, fine movements may result in tissue damage, contraction, and loss of function. In order to minimize tissue trauma, choroidal tissue is clamped between a support structure to facilitate tissue integrity (avoids contraction), maintain tissue orientation, and limits forceps-injury to the delicate choroidal tissues (supported with the clamp). Thus, proper alignment and placement of this clamp for donor tissue is addressed with an example of the present subject matter. One example of the present subject matter will enable intraocular clamping of autologous tissue, inside the eye, for translocation to the target location while minimizing trauma, preventing contraction, and maintaining proper alignment. 
     An example of the present subject matter addresses some of these challenges. One example includes a shape memory material that has a first physical configuration at a first temperature and a second physical configuration at a second temperature. One example includes a first ring and a second ring affixed together at a joint and the joint is configured to allow one ring to articulate relative to the other ring and configured to provide structural rigidity sufficient to support the tissue. One example includes a joint having a grasping portion to allow manipulation using forceps. One example includes a tool attachment feature to allow manipulation of a portion of a leading edge of a ring. 
     Each of these non-limiting examples can stand on its own, or can be combined in various permutations or combinations with one or more of the other examples. 
     This overview is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIGS.  1 A and  1 B  include isometric views of a device, according to one example. 
         FIG.  2    includes a view of a partially fabricated device, according to one example. 
         FIG.  3    includes a view of a portion of a device, according to one example. 
         FIG.  4    includes a view of a device during a surgical procedure, according to one example. 
         FIG.  5    includes a view of a device during a surgical procedure, according to one example. 
         FIG.  6    includes a view of a flowchart of a manufacturing method, according to one example. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1 A and  1 B  include isometric views of device  100 A, according to one example. Device  100 A can be fabricated of sheet stock, such as a metal or a polymer. Device  100 A includes first ring  110 A and second ring  120 A coupled together by joint  140 A. First ring  110 A and second ring  120 A each have an open center, as shown at aperture  90 , and inner edge and outer edge. In the example shown, both inner edge and outer edge are configured with teeth  170 A. Teeth  170 A are curved in an inward direction such that a tissue disposed between first ring  110 A and second ring  120 A is retained thereby. In addition, both first ring  110 A and second ring  120 A have a plurality of apertures  160 , and in the example shown, each aperture  160  has teeth, here each of which are referred to as bur  150 . Bur  150  and teeth  170 A engage with the tissue disposed between the rings. 
     Teeth  170 A and burs  150  can be fabricated in a punching operation, a piercing operation, or by a laser cutting and press forming operation. 
     In the example shown, first tool connector  210 A includes an aperture configured to pass through the thickness of first ring  110 A (as depicted in  FIG.  1 A ), configured to pass through the thickness of second ring  120 A (as shown in  FIG.  1 B ), or pass through one ring only. First tool connector  210 A can be sized and positioned to receive a suture or to receive a corresponding tool having a suitable mandrel. 
     In the example shown, second tool connector  220 A is coupled to first ring  110 A as depicted in  FIG.  1 A  and is separated from second ring  120 A as shown in  FIG.  1 B . Second tool connector  220 A can include a cantilevered tab. 
       FIG.  2    includes a view of partially fabricated device, according to one example. As shown, the device includes first ring  110 A and second ring  120 A coupled together by joint  140 B. First ring  110 A and second ring  120 A include teeth  170 B distributed about inner edge and outer edge in a sawtooth manner and two burs  150  associated with each aperture  160  within the field of rings  110 A and  120 A. 
     During fabrication, the device is cut to a form as shown in the figure. Cutting can include etching, laser cutting, or stamping. Further processing includes forming teeth  170 B and burs  150 . Teeth  170 B and burs  150  can be formed in a press operation or in a combined cutting and forming operation. Teeth  170 B and burs  150  are deflected from the plane of the first ring  110 A and second ring  120 B. First tool connector  210 C includes through holes in both first ring  110 B and second ring  120 B. 
     In addition, the device fabrication process includes folding at joint  140 B. The device shown illustrates joint  140 B having second tool holder  220 B configured to couple with first ring  110 A and separate from second ring  120 A. When folded as depicted in the figures, the major apertures of first ring  110 A and second ring  120 A are aligned. 
     Joint  140 B has a width depicted here as W 1  and second tool connector  220 B has a width depicted here as W 2 . The joint resiliency is a function of the difference between dimensions W 1  and W 2 . The clamping force exerted on tissue disposed between first ring  110 A and second ring  120 A is determined, in part, by the difference between dimensions W 1  and W 2 . 
       FIG.  3    includes a view of a portion of a device, according to one example. The figure illustrates first ring  110 B aligned atop second ring  120 B. Second ring  120 B has surface treatment  310 . Surface treatment  310  can include a formed texture, roughness, a coating, or other agent to facilitate bonding of tissue and the device. Surface treatment  310  can be applied to inside surface of first ring  110 B. First ring  110 B includes holes  320 . Holes  320  have exposed edges that can assist in bonding tissue and the device. First ring  110 B and second ring  120 B include teeth  170 B distributed on both inner edges and outer edges. In the example shown, teeth  170 B have a slender profile and a circular gullet. Other profiles are also contemplated including a rectangular profile of castellations. 
       FIG.  4    includes a view of device  100 B during a surgical procedure, according to one example. Device  100 B is shown to be loosely folded in a manner resembling a formed taco. Device  100 B is shown inside of a lumen of introducer  410 . For device deployment, rubber stopper  420  is urged in a direction to eject device  100 B from introducer  410  and into an eye. 
     In addition, tool  430  can be manipulated by a user to facilitate a surgical procedure. Tool  430 , in the example shown, has a flat portion akin to a blade or spatula. In one example, an end of a needle or wire can be flattened along a portion of a length. Tool  430  can be useful for folding device  100 B into the configuration shown. In addition, tool  430  can be manipulated to engage with a suture and facilitate removal from within introducer  410 . An edge of tool  430  can be maneuvered to exert a pulling force on a suture (or other structure of device  100 B) in order to extract device  100 B from within introducer  410 . 
       FIG.  5    includes a view of a device during a surgical procedure, according to one example. In this view, forceps  510  engage with suture  530 . Suture  530  passes through aperture  210 D, here shown through second ring  120 C. Suture  530  facilitates tugging the device into position on the tissue site. During placement of the device at a tissue site, forceps  510  are urged in a direction indicated by arrow  512 . After manipulating to a tissue site, the force exerted by forceps  510  is relaxed and a clamping force is exerted on the tissue by the action of the joint coupling first ring  110 C and second ring  120 C. 
     Forceps  520  are engaged with second tool connector  2200 . Forceps  520  can be moved in the direction shown by arrow  522  to engage the device with tissue at a target site. Forceps  520  can also facilitate alignment of the plane of the device with that of the tissue. 
     In one example, a single suture passes through aperture  210 D in second ring  120 C. 
     In one example, a first suture passes through apertures of both first ring  110 C and second ring  120 C and a second suture passes through aperture  210 D in second ring  120 C. In a surgical procedure, the first suture (passing through both rings) can be engaged by a tool, such as tool  430 , for withdrawal, and after exiting the introducer  410 , the first suture is removed by a cutting operation. Thereafter, the remaining suture is manipulated as shown in the figure. 
       FIG.  6    includes a view of a flowchart of manufacturing method  600 , according to one example. At  610 , method  600  includes forming a first ring member. First ring member can be fabricated by stamping, laser cutting, etching, photolithography, molding, diecasting, or other fabrication process involving additive or subtractive manufacturing equipment. In one example, this can include forming a shape memory allow. 
     At  620 , method  600  includes forming a second ring member. Second ring member can be fabricated by stamping, laser cutting, etching, photolithography, molding, diecasting, or other fabrication process involving additive or subtractive manufacturing equipment. In one example, this can include forming a shape memory allow. 
     At  630 , method  600  includes thermal processing. Thermal processing can include heating, cooling, quenching, soaking, and other manufacturing techniques to impart a memory function to the device. For example, thermal processing can including various combinations of heating and cooling whereby the finished device can be deflected from a natural configuration and when the device temperature returns to a normal body temperature, the device reverts to a configuration in which the first ring member and the second ring member are clamped on a membrane of tissue. 
     Various Notes 
     A device as described herein can be fabricated of a variety of different materials. In one example, a device includes a metal structure. The metal can include an alloy of stainless steel, titanium, or nitinol. In one example, the device includes a polymer. A polymer can be configured to have a shape memory aspect. The device can be fabricated by stamping, diecasting, laser cutting, etching, or other manufacturing technique. 
     Fabrication can include treatment using a thermal processing to impart a thermal memory property whereby at a first temperature, the device is urged to take on a first configuration and at a second temperature (different than the first temperature), the device is urged to take on a second configuration, In one example, the first configuration is folded as shown in  FIGS.  1 A and  1 B , and in a second configuration, the device is partially folded or fully open as in  FIG.  2   . 
     The first ring can be described as an anterior ring and the second ring can be described as a posterior ring. The posterior ring can be configured with a tab at the joint for manipulating the device. In one example both the anterior ring and the posterior ring have a formed tab at the joint in which forceps can be used to draw together a portion of the tabs and thereby cause the leading edge of the rings to open in the manner of a chip clip. The dimensions of the joint can be selected to adjust the clamping force exerted by the device. 
     A device includes an apparatus or a fixture having a first ring member and a second ring member. The first ring member can have a first open center. The first ring member can include a first tool connector disposed at a first radial position relative to the first open center. The second ring member can have a second open center coupled to the first ring member at a joint. The joint is disposed at a second radial position relative to the first open center. The joint can have a second tool connector. The joint can be configured to enable movement of the first ring member relative to the second ring member. 
     The first ring member, the second ring member, and the joint can include a shape memory material. 
     The first ring member and the second ring member can include a shape memory metal. 
     In one example, the first ring member and the second ring member have a profile that is configured to substantially conform to a radius of greater than 2 cm. 
     In one example, the first radial position differs from the second radial position. For example, the first radial position and the second radial position can be separated by substantially 180 degrees. 
     In one example, the first open center and the second open center have a substantially similar diameter. 
     The first tool connector or the second tool connector can include a hole, a knob, and a notch. 
     The second tool connector can be configured to articulate with the second ring member. 
     In one example, the joint includes a hinge. The hinge can include an elastic element or can include a pivot configuration and other portions of the device can include a locking member to retain the first ring member in a fixed position relative to the second ring member. 
     In one example, either or both of the first ring member and the second ring member includes a perforation. The perforation can include a pierced aperture or a die-formed bur. In one example, a plurality of perforations are provided. 
     In various examples, the first ring member or the second ring member includes a tooth or a castellation at an edge. The tooth or castellation can be disposed at an inner edge or disposed at an outer edge. In one example, the edge (such as an inner edge or an outer edge) includes a sawtooth profile. 
     The edges (such as the inner edge or outer edge) can have points that are aligned or staggered. 
     One example of the present subject matter includes a method of manufacturing a fixture. The method can include forming a first ring member having a first open center and having a first tool connector disposed at a first radial position relative to the first open center. The method can include forming a second ring member having a second open center coupled to the first ring member at a joint. The joint can be disposed at a second radial position relative to the first open center. The joint can have a second tool connector. 
     The manufacturing method can include forming a shape memory material. This can include forming a first configuration corresponding to a first temperature and forming a second configuration corresponding to a second temperature. Fabrication can include fabricating using a shape memory metal. Fabrication can also include cutting and forming sheet stock. Forming can include forming a hole disposed at a first radial position or forming a tab at a second radial position. In one example, the method includes fabricating a joint, wherein the joint is configured to articulate with the second ring member. In one example, forming includes providing at least one perforation, providing at least one castellation at an edge, or providing at least one sawtooth profile at an edge. 
     The above description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. 
     In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. 
     In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more,” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     Geometric terms, such as “parallel”, “perpendicular”, “round”, or “square”, are not intended to require absolute mathematical precision, unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent functions. For example, if an element is described as “round” or “generally round,” a component that is not precisely circular (e.g., one that is slightly oblong or is a many-sided polygon) is still encompassed by this description. 
     The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.