Composite suture needle having an elastically deformable section

Abstract

A composite suture needle configured to pass through smaller cannulas used in minimally invasive surgery includes a curved elongated body made of stainless steel. The curved elongated body has a proximal end and a distal end with a pointed tip. The composite suture needle includes a sheath overlying the curved elongated body. The sheath is curved to conform to the shape of the curved elongated body. The sheath is made of a material that is more elastic than the curved elongated body. The pointed tip of the curved elongated body extends distally beyond the distal end of the sheath. The curved elongated body is made of stainless steel, and the sheath is made of a material, such as nitinol, that is more elastic than the elongated body.

Description

Technical Field

[0001] This patent application generally relates to surgical procedures and surgical tools, and more specifically, to systems, devices, and methods for manufacturing and using an elastic suture needle that passes through a lumen, such as those associated with a trocar and cannula (hereinafter referred to as a cannula).

Background Art

[0002] Surgeons use a lumen, such as a cannula, to position surgical tools, such as suture needles, at the surgical site. The size of the suture needle that can pass through the cannula is limited by the size of the opening of the cannula. In many cases, surgeons desire to use a larger curved suture needle (i.e., a suture needle having a curvature larger than the cannula opening) to close the surgical wound and repair anatomical features, but passing a larger curved suture needle through a smaller cannula is difficult.

[0003] A 5 mm cannula is often used during minimally invasive surgeries (MIS), but surgeons are forced to use only smaller suture needles because they cannot pass larger suture needles through a 5 mm cannula. Smaller suture needles are not optimal because, among other things, they often require the surgeon to pass the suture needle and suture thread through more tissue, which can lengthen the surgical procedure and frustrate the surgeon. Using smaller needles can also result in a bite distance that exposes the wound or anatomical feature to a risk of separation.

[0004] Another drawback of using smaller suture needles is that it is not possible to easily attach a larger size suture thread to a smaller suture needle. This often results in the surgeon using a suture thread of a smaller size than required for the suturing procedure. Thus, when a thin or smaller size suture thread is passed through tissue with a smaller bite size, a cheese wire effect may occur, thereby cutting the tissue that the suture thread was intended to hold.

[0005] In order to solve one or more of the above problems, progress has been made in providing a suture needle made of a superelastic alloy having shape memory properties, which enables a curved suture needle to be straightened to pass through a cannula. When the superelastic suture needle is removed from the other end of the cannula for use at the surgical site, its shape memory properties cause it to return to its original curved shape.

[0006] An alloy generally referred to as nitinol is often used to make superelastic suture needles. However, suture needles made of nitinol can be very difficult to machine, which results in high production costs that are often billed to the customer and may substantially limit the adoption of nitinol suture needles for minimally invasive surgery.

[0007] In addition, there are many issues associated with fixing the suture thread to the suture attachment barrel of the nitinol suture needle. These issues include the tendency of the suture attachment barrel of the nitinol needle to spring back after the crimping process, which results in the formation of a weak attachment between the suture thread and the nitinol suture needle. Summary of the Invention Problems to be Solved by the Invention

[0008] Accordingly, there is a need for an improved suture needle that exhibits elasticity so that a larger suture needle for use in a surgical procedure can be passed through a relatively small cannula (e.g., a 5 mm cannula). There is also a need for a suture needle that cannot undergo plastic deformation when passed through a smaller cannula. In addition, there is a need for a system, device, and method for making a larger suture needle made primarily of stainless steel that can elastically deform to be passed through a relatively small cannula for use in minimally invasive surgery.

Means for Solving the Problems

[0009] Introducing a curved suture needle into the field of minimally invasive surgery is difficult. When a curved suture needle is introduced through a device having a lumen such as a cannula, the size of the curved suture needle is typically limited to a profile smaller than the inner diameter of the cannula. One way to introduce a larger needle through a smaller cannula is to bend or curve the needle to a profile that fits within the inner diameter of the cannula. This will typically result in the curved suture needle undergoing some degree of plastic deformation, which requires reshaping the suture needle after it has entered the surgical site and before it can be used for suturing.

[0010] Another approach is to manufacture a suture needle made entirely of a superelastic material such as nitinol (i.e., a metal alloy made from nickel and titanium). However, doing so results in a suture needle that is not as strong as suture needles made from more commonly used materials (e.g., 455, 420, 300 series alloys, or custom alloys such as tungsten-rhenium alloys), and thus the suture needle is not optimal for subsequent suturing procedures. Furthermore, there are substantial challenges in the processing of nitinol alloy suture needles, including point grinding, curve setting, hole drilling, electropolishing, and suture thread attachment. Attempts to overcome the problems identified above typically result in the production of low-quality and / or high-cost suture needles.

[0011] Most materials can withstand a moderate amount of strain before plastic deformation. Highly elastic materials (i.e., alloys that exhibit high yield strain) can withstand greater strain before plastic deformation compared to less elastic materials. In one embodiment, the composite suture needle includes a highly elastic material at the maximum distance from the neutral axis, which can withstand greater bending before plastic deformation compared to a suture needle made from a single less elastic material having uniform elastic properties. This is because the outer diameter of the core material is smaller than the actual outer diameter of the composite suture needle.

[0012] In one embodiment of the present patent application, the suture needle can be manufactured from a core wire stock that includes a core section made at least in part of a strong alloy (e.g., a martensitic age-hardened alloy such as ETHALLOY® Needle Alloy, or stainless steel including 455, 420, 300, or other custom alloys), and a second material having highly elastic properties (e.g., nitinol).

[0013] In one embodiment, the suture needles disclosed herein preferably have a higher strength than suture needles made entirely of a highly elastic material (e.g., nitinol), and the suture needles have a strength that is fully suitable for use in suturing tissue.

[0014] When a curved suture needle having a curved elongated body is bent (e.g., flattened) to pass through a cannula, the maximum bending occurs in the middle section of the curved elongated body located between the tissue-penetrating end and the suture thread attachment end. When bent, the maximum strain occurs along the inner and outer radial surfaces of the curved elongated body. The curved elongated body has a neutral axis near the center of the cross-section of the elongated body. There is no significant shear strain occurring along the neutral axis, but the degree of shear strain increases as the distance from the neutral axis increases.

[0015] In one embodiment, a composite suture needle having a large size and a conventional curvature (e.g., having a semi-circular shape) can be passed through a lumen such as a cannula. The composite suture needle is elastically straightened when passing through the cannula and springs back to its original curvature when removed from the end of the cannula for surgical use.

[0016] In one embodiment, the composite suture needle preferably includes an elongated body having a proximal end and a distal end with a sharp tip, and a sheath overlapping the elongated body.

[0017] In one embodiment, the sheath includes a material that is more elastic than the elongated body.

[0018] In one embodiment, the elongated body and the sheath are curved.

[0019] In one embodiment, the sharp tip extends distally beyond the distal end of the sheath.

[0020] In one embodiment, the elongated body is made of a strong alloy such as stainless steel, and the sheath is made of a highly elastic material such as nitinol.

[0021] In one embodiment, the stainless steel used to make the elongated body can include austenitic stainless steel, martensite-aged (marage) stainless steel, and stainless steel sold under the registered trademark ETHALLOY Needle Alloy.

[0022] In one embodiment, the elongated body preferably has a reduced diameter section defining a first outer diameter, and the distal end of the elongated body defines a second outer diameter that is larger in size than the first outer diameter of the reduced diameter section.

[0023] In one embodiment, the distal end of the elongated body includes a tapered section having a proximal end including a shoulder defining the second outer diameter. In one embodiment, the tapered section preferably has a distal end including a sharp tip.

[0024] In one embodiment, the sheath has a proximal end, a distal end, and a lumen extending from the proximal end to the distal end of the sheath. In one embodiment, the reduced diameter section of the elongated body is disposed within the lumen of the sheath. In one embodiment, the lumen of the sheath has an inner diameter that is greater than or equal to the outer diameter of the first reduced diameter section of the elongated body.

[0025] In one embodiment, the sheath has an outer surface that defines a third outer diameter that approximates the second outer diameter of the shoulder of the tapered section of the elongated body.

[0026] In one embodiment, the composite suture needle preferably includes an elongated body having a curved proximal body section, a curved distal body section, and a curved intermediate section extending between the curved proximal body section and the curved distal body section. In one embodiment, the composite suture needle preferably includes a sheath that overlays the curved intermediate section of the elongated body. The curved intermediate section of the elongated body is preferably made of a first material, and the sheath is made of a second material that is more elastic than the first material of the curved intermediate section.

[0027] In one embodiment, the curved proximal section, the curved distal section, and the curved intermediate section of the elongated body form a single structure. In one embodiment, the curved proximal section, the curved distal section, and the curved intermediate section of the elongated body are made of the same material, such as stainless steel.

[0028] In one embodiment, the curved intermediate section of the elongated body and the sheath that overlays the curved intermediate section preferably define a flexible region of the composite suture needle that is more elastic than the curved proximal body section and the curved distal body section of the elongated body of the composite suture needle.

[0029] In one embodiment, the curved intermediate section of the elongated body is made of stainless steel, and the sheath that overlays the curved intermediate section is made of a highly elastic material such as nitinol.

[0030] In one embodiment, the sheath preferably has a proximal end, a distal end, and a lumen extending from the proximal end to the distal end of the sheath. In one embodiment, the curved intermediate section of the elongated body is disposed within the lumen of the sheath.

[0031] In one embodiment, the curved intermediate section of the elongated body has a first outer diameter, and the lumen of the sheath has a first inner diameter that is greater than or equal to the first outer diameter of the curved intermediate section of the elongated body.

[0032] In one embodiment, the distal end of the curved proximal section and the proximal end of the curved distal section of the elongated body define a second outer diameter. In one embodiment, the sheath has an outer surface that defines a third outer diameter approximating the second outer diameter.

[0033] In one embodiment, the proximal body section of the elongated body preferably includes a proximal end face, and the suture receiving hole is formed in the proximal end face.

[0034] In one embodiment, the curved distal body section of the elongated body includes a tissue piercing point at its distal end.

[0035] In one embodiment, the sheath can be adhered or welded to the curved intermediate section of the elongated body.

[0036] In one embodiment, the composite suture needle preferably includes a curved proximal body section made of stainless steel, a curved distal body section made of stainless steel, and a connector interconnecting the curved proximal body section and the distal body section.

[0037] In one embodiment, the connector is preferably made of a material that is more elastic than the stainless steel used to make the curved proximal body section and the curved distal body section.

[0038] In one embodiment, the connector interconnects the distal end of the curved proximal body section with the proximal end of the curved distal body section.

[0039] In one embodiment, the connector may include a double-tail structure for connection to the distal end of the curved proximal body section and the proximal end of the curved distal body section.

[0040] In one embodiment, the connector preferably has an outer diameter that approximates the outer diameter of the distal end of the curved proximal body section of the composite suture needle and the outer diameter of the proximal end of the curved distal body section.

[0041] In one embodiment, the connector is made of nitinol, and the stainless steel used to make the proximal body section and the distal body section may be austenitic stainless steel, martensite-aged (maraging) stainless steel, and / or stainless steel sold under the registered trademark ETHALLOY Needle Alloy.

[0042] In one embodiment, the elongated body of the composite suture needle is curved along its length, one surface of the elongated body defines the concave surface of the curve, and another surface of the elongated body defines the convex surface of the curve.

[0043] In one embodiment, the surgical method preferably includes passing a composite suture needle through the lumen of a cannula from the proximal end to the distal end of the cannula, whereby during the passing step, the composite suture needle flattens to deform to a height that is below the height of the lumen.

[0044] In one embodiment, after the passage step, the composite suture needle is preferably removed from the distal end of the cannula, where the composite suture needle deforms and returns to a curved shape having a height greater than the height of the lumen of the cannula.

[0045] In one embodiment, the composite suture needle can be elastically deformed to reduce the height and / or profile of the suture needle so that the suture needle can pass through a cannula such as a cannula having a diameter of 5 mm or less.

[0046] In one embodiment, a needle driver can be used to secure the distal end of the composite suture needle to the suture thread attachment barrel of the composite suture needle following behind the tip of the composite suture needle. In one embodiment, the tip is preferably surrounded by a clamp jaw at the distal end of the needle driver to protect the tip when the composite suture needle passes through the cannula. The clamp jaw preferably surrounds and protects the tip to prevent the tip from contacting the inside of the cannula when the tip passes through the cannula, thereby avoiding damage to the tip during passage through the cannula.

[0047] In one embodiment, when the composite suture needle is held by a needle driver, the tip of the composite suture needle does not extend or protrude outside the outer surface of the needle holder.

[0048] In the case of a suture needle made of 420 alloy, since the core wire is the same as the needle wire being currently drilled, forming a hole by mechanical drilling can be successfully completed using conventional methods.

[0049] In one embodiment, while leaving the outer shell of the more chemically inert nitinol intact, the core alloy can be chemically leached or electropolished to a specified depth at the proximal end of the needle to create a hole for attachment of the suture needle, which may be particularly applicable when using a high-strength maraging alloy or the like as the core material.

[0050] In one embodiment, since the tip end is made of a core wire material and is not a superelastic material (e.g., not nitinol), grinding the tip end and / or forming a cutting edge may be easier.

[0051] In one embodiment, the core alloy enables the needle to be bent with conventional bending equipment used in the technical field of suture needle manufacturing, so curve setting can be facilitated. By enabling the core alloy to plastically deform during the bending process, it provides resistance to nitinol, which has a tendency to straighten back to its original form after the application of conventional bending methods.

[0052] In one embodiment, the suture needles can be collected in bulk and efficiently routed through the shape setting heat cycle, thus eliminating the need for additional handling required to shape heat curing fixtures and monolithic nitinol alloy needles.

[0053] In one embodiment, when the needle needs to be bent to pass through a cannula, the maximum bending occurs between the tissue penetrating end and the suture attachment end (i.e., the intermediate section). When bent, the maximum strain occurs along the inner radius surface and the opposite outer radius surface.

[0054] In one embodiment, a method of manufacturing a composite suture needle preferably includes obtaining a single core wire made of a suitable material for use in manufacturing the suture needle. The core wire preferably includes an outer diameter, a first end, and a second distal end.

[0055] In one embodiment, the method preferably includes obtaining an outer sheath (e.g., a sleeve, a tube) having a length equal to or shorter than the length of the core wire. The sheath preferably has a proximal end and a distal end.

[0056] In one embodiment, the sheath preferably has an inner diameter slightly larger than the outer diameter of the core wire and an outer diameter approximating the desired finished outer diameter of the composite suture needle.

[0057] In one embodiment, one core wire is disposed inside the sheath so as to align the proximal end of the core wire with the proximal end of the sheath.

[0058] In one embodiment, the sheath can be fixed to the core wire using a heat shrink fitting process. In one embodiment, the sheath can be heated to thermally expand the diameter of the sheath to enable the sheath to slide over the core wire (e.g., an elongated body made of stainless steel). After the sheath is positioned over the core wire, the sheath can be cooled to thermally contract the diameter of the sheath and grip or fit snugly over the core wire, thereby forming a composite suture needle having a flexible region covered by the sheath.

[0059] In one embodiment, the sheath can be attached to the core wire by applying an adhesive in the space between the outer diameter of the core wire and the inner diameter of the sheath.

[0060] In one embodiment, the sheath can be attached to the core wire by using a bonding material between the outer diameter of the core wire and the inner diameter of the sheath, whereby the bonding material is weldable to both the core wire material and the sheath material.

[0061] In one embodiment, a hole for receiving a suture can be formed within the composite suture needle by drilling into the core material at the proximal end of the composite structure or, particularly in the case of a high-strength mar-arged alloy, electrochemically etching / leaching the core wire to a specified depth to create a symmetric suture-receiving hole.

[0062] In one embodiment, the distal end of the core wire can be ground (or material removed) from the distal end of the composite structure to form a point at the distal end of the composite suture needle.

[0063] In one embodiment, the composite suture needle may have a stainless - steel core and a connector component made of a highly elastic material that exists only along the inner - radius surface and the opposite outer - radius surface of the suture needle. The fitting of the highly elastic connector component to the conventional suture - needle material of the core can be achieved in a manner similar to a sheath or sleeve configuration (e.g., fixation, adhesion, or welding). However, in one embodiment, the highly elastic connector component may include a mechanical attachment structure such as a double - tail joining component.

[0064] In one embodiment, the composite suture needle can be curved by known equipment and methods in the art to produce a self - standing composite suture needle having a steel core and a nitinol sheath, which can then be heat - treated to shape the outer nitinol sleeve component without the need for a jig or complex additional processes.

[0065] In one embodiment, when the core material of the composite suture needle is a martensite - aged alloy, the shape - setting and precipitation - strengthening heat - treatment steps can be carried out simultaneously (e.g., at 480 °C or higher for 2 minutes or more).

[0066] In one embodiment, the method of manufacturing a composite suture needle preferably includes obtaining a core wire made of a suitable material for use in manufacturing the suture needle, the core wire having an outer diameter, a proximal end, and a distal end, and forming a thin strip of nitinol around the steel core wire by simultaneously pulling the steel core wire and a nitinol strip through a series of reducing dies suitable for manufacturing circular tubes.

[0067] In one embodiment, when a nitinol tube is formed around the steel core through the progression of the die - drawing process, the seam of the nitinol can be welded by laser or micro - TIG welding technology.

[0068] In one embodiment, the elastic sheath may be shorter than the core wire.

[0069] In one embodiment, the composite suture needle can be mechanically drilled and / or laser drilled to form a suture receiving hole.

[0070] In one embodiment, the suture receiving hole can be formed chemically or electrochemically by etching the core material.

[0071] In one embodiment, the composite suture needle can be curved into a specified self-standing shape and then heat treated in bulk to complete the shaping process.

[0072] These and other preferred embodiments of the present invention will be described in more detail below.

Brief Description of the Drawings

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Best Mode for Carrying Out the Invention

[0074] Figures 1A - 1C show a conventional suture needle 50 having an elongated body 52 with a proximal end 54 and a distal end 56. The elongated body 52 of the suture needle 50 is curved and has a semi - circular or semi - circular shape.

[0075] The suture needle 50 includes a suture attachment barrel 58 adjacent to the proximal end 54 of the elongated body 52, and a suture attachment opening 60 formed in the proximal surface of the suture attachment barrel. The end of a surgical suture (e.g., a filamentous element) is inserted into the suture attachment opening 60, and the suture attachment barrel 58 is crimped to fix the end of the surgical suture to the suture attachment barrel 58 of the elongated body 52 of the suture needle 50.

[0076] The suture needle 50 includes a tip 62, such as a sharp or pointed tip, which is integral with the distal end 56 of the elongated body 52 and defines the leading or most distal end of the suture needle 50. The tip 62 is sharpened to facilitate piercing tissue during a suturing operation and passing the distal end 56 of the elongated body 52 of the suture needle 50 through the tissue.

[0077] Referring to FIGS. 1B and 1C, the elongated body 52 of the suture needle 50 includes an inner radial surface 64 (i.e., a concave curved surface) extending along the inside of the curve of the curved elongated body 52, and an outer radial surface 66 (i.e., a convex curved surface) extending along the outside of the curve of the curved elongated body 52. The inner radial surface 64 and the outer radial surface 66 of the elongated body 52 define the thickness T of the elongated body 52 of the suture needle 50, whereby the axis for measuring the thickness T of the elongated body is perpendicular to the neutral axis A of the elongated body 52 of the suture needle 50.

[0078] When the suture needle 50 is in its original semi-circular configuration, the elongated body 52 of the suture needle 50 defines a height H. When an external force is applied to the outer surface of the elongated body 52 of the suture needle 50 (e.g., when passing the suture needle through the lumen of a cannula), the elongated body bends, curves, straightens, and / or flattens so as to deform into an elongated body having a height or profile lower than the original height H.

[0079] Referring to FIGS. 1C and 1C-1, the elongated body 52 of the suture needle 50 has a length L extending along the neutral axis A of the elongated body 52. N The neutral axis L N extends between the proximal end 54 and the distal end 56 of the elongated body 52, which is also referred to as the neutral length of the suture needle 50. The elongated body 52 of the suture needle 50 has an upper length L extending between the proximal end 54 and the distal end 56 of the elongated body 52 along the inner radial surface 64 of the elongated body 52 T and a bottom length L extending between the proximal end 54 and the distal end 56 of the elongated body 52 along the outer radial surface 66 of the elongated body 52. B

[0080] Referring to FIG. 1C-1, when the middle section 68 of the elongated body 52 of the suture needle 50 is straightened to pass through the cannula, tensile and compressive forces are applied to the respective inner surface 64 and outer surface 66 of the elongated body 52 of the suture needle 50. When the middle section 68 of the elongated body 52 is straightened, the inner radial surface 64 of the elongated body 52 is under tension and the outer radial surface 66 of the elongated body 52 is under compression. The portion of the elongated body 52 extending along the neutral axis A that defines the neutral length L of the elongated body 52 is neither under tension nor under compression. The elastic strain calculations associated with deforming the semi-circular suture needle (shown in FIGS. 1A-1C and 1C-1) into a straight configuration can be calculated using the formula ε = ΔL / L N where ΔL is the change in the upper length L of the suture needle at the inner radial surface 64 of the elongated body 52 N or the change in the bottom length L of the suture needle at the outer radial surface 66 of the elongated body 52 T and L B is N ​is the neutral length of the elongated body of the suture needle that is intermediate between the inner radial surface 64 and the outer radial surface 66 of the elongated body.

[0081] When the suture needle 50 is bent to pass through the lumen of the cannula, the maximum bending occurs in the intermediate section 68 of the elongated body 52. When bent, the maximum strain occurs along the inner radial surface 64 and the outer radial surface 66 of the elongated body 52. The neutral length L N along which the neutral axis A extends is near the center of the cross-section of the elongated body. During bending (e.g., straightening) of the elongated body, there is no shear strain occurring along the neutral axis A that extends along the neutral length L N of the elongated body 52. However, as the distance from the neutral axis L N increases, the degree of strain increases. Thus, during bending of the suture needle 50, the shear strain is greater at the inner radial surface 64 and the outer radial surface 66 and lower, or negligible, along the neutral length L N .

[0082] In one embodiment, the composite suture needle preferably includes a core component made of a first material and a second component made of a second material that is more elastic than the first material. In one embodiment, the first component may include a core component made of stainless steel, and the second component may include an outer sheath made of a highly elastic material (e.g., nitinol) that covers a section of the core component.

[0083] Referring to FIGS. 2A and 2B, in one embodiment, the composite suture needle 100 preferably includes an elongate body 102 (i.e., the core component) having a proximal end 104 and a distal end 106. In one embodiment, the distal end 106 of the elongate body 102 preferably includes a tapered section 108 having a proximal end 110 that defines a shoulder 112 and a distal end 114 that includes a sharp or pointed tip 116. The tapered section 108 preferably tapers inwardly between its proximal end 110 and its distal end 114. In one embodiment, the pointed tip 116 at the distal end 114 of the tapered section 108 preferably defines a leading end of the elongate body 102 that is designed to pierce tissue to facilitate passage of the distal end 106 of the elongate body 102 through tissue during a suturing procedure.

[0084] In one embodiment, the elongate body 102 of the composite suture needle 100 preferably includes a reduced diameter section 118 that extends between the proximal end 104 of the elongate body and the larger diameter shoulder 112 of the tapered section 108. In one embodiment, the reduced diameter section 118 has a cross-section with a circular shape configured to receive a sheath made of a highly elastic material, as described in more detail herein.

[0085] Referring to FIG. 2B, in one embodiment, the reduced diameter section 118 of the elongate body 102 preferably defines a first outer diameter OD 1 and the shoulder 112 of the tapered section 108 preferably defines a second outer diameter OD 1 that is larger than the first outer diameter OD 2 of the reduced diameter section 118 of the elongate body 102.

[0086] Referring to FIGS. 2A and 2B, in one embodiment, the elongated body 102 can be curved and / or can have a semi-circular or semi-elliptical shape. In one embodiment, the reduced diameter section 118 of the elongated body 102 is curved and preferably includes a concave surface 120 extending along the inside of the curve of the reduced diameter section and a convexly curved outer surface 122 extending along the outside of the curve of the reduced diameter section 118. The elongated body 102 preferably defines a first height H 1 thereby.

[0087] In one embodiment, the elongated body 102 can be made of a strong alloy such as stainless steel. In one embodiment, the stainless steel can include austenitic stainless steel (302SS) and martensitic aged (maraging) stainless steel (455SS).

[0088] Austenitic stainless steel (302SS) can possess austenite as their primary crystal structure. The austenite crystal structure is achieved by sufficient addition of nickel, manganese, and nitrogen, which are austenite stabilizing elements. Due to their crystal structure, austenitic steels are not hardenable by heat treatment. See https: / / en.wikipedia.org / wiki / Austenitic_stainless_steel. Nevertheless, very high strength can be achieved by work hardening, especially in the wire drawing process used to produce feedstock for needle manufacturing.

[0089] Martensite-aged (marage) stainless steel (455SS) is a steel known to preferably have excellent strength and toughness without losing ductility. The "aging" part of the term marage refers to an extended heat treatment process. These steels are a special class of low-carbon ultra-high-strength steels whose strength is derived from the precipitation of intermetallic compounds rather than carbon. Typically, the main alloying element is 7 - 25 wt% nickel. Secondary alloying elements including titanium and copper are added to form intermetallic precipitates. See https: / / www.asminternational.org / c / portal / pdf / download?articleId=AMP16909P30&groupId=10192.

[0090] One type of martensite-aged alloy that is specifically developed for and provides a level of strength far exceeding that of alloys previously used to make suture needles is sold under the registered trademark ETHALLOY Needle Alloy. ETHALLOY Needle Alloy is strengthened by a combination of work hardening and heat treatment (precipitation strengthening).

[0091] Referring to FIGS. 3A and 3B, in one embodiment, the composite suture needle 100 preferably includes a sheath 124 made of a material having a higher level of elasticity than the material used to make the elongated body 102 (FIGS. 2A and 2B) of the composite suture needle. In one embodiment, the sheath 124 can be made of a highly elastic material such as nitinol. In one embodiment, the sheath 124 can have a sleeve shape, a tube shape, or a cylindrical shape. In one embodiment, the sheath 124 is preferably sized, shaped, and / or configured to be assembled over the reduced diameter section 118 of the elongated body 102 (FIGS. 2A and 2B) to form a composite suture needle 100 that includes an elongated body with relatively low elasticity and a sheath 124 with relatively high elasticity compared to the material used to make the elongated body.

[0092] In one embodiment, the sheath 124 preferably has a proximal end 126, a distal end 128, and a lumen 130 extending from its proximal end 132 to its distal end 134. Referring to FIGS. 2B and 3B, in one embodiment, the lumen 136 of the sheath 124 preferably has an inner diameter ID 1 that is slightly larger than the outer diameter OD 1 of the reduced-diameter section 118 of the elongate body 102. In one embodiment, the sheath 124 preferably has an outer surface 132 that defines an outer diameter OD 2 that approximates the outer diameter OD 3 of the shoulder 112 of the tapered section 108 of the elongate body 102. In one embodiment, when the sheath 124 is assembled onto the reduced-diameter section 118 of the elongate body to form the composite needle 100, the distal end 128 of the sheath 124 preferably abuts the shoulder 112 of the tapered section 108 of the elongate body 102. In one embodiment, the outer surface 132 of the sheath 124 approximates the outer surface at the proximal end 110 of the tapered section 108 of the elongate body to provide a smooth transition between the tapered section 108 of the composite suture needle and the sheath 124.

[0093] In one embodiment, the sheath preferably covers most of the length of the elongate body. In one embodiment, the proximal end of the sheath preferably extends proximally beyond the proximal end of the elongate body to provide a suture-receiving aperture. In one embodiment, the sheath may slide over the elongate body to form a thermal fit and / or a compression fit between the sheath and the elongate body.

[0094] Referring to FIGS. 4A and 4B, in one embodiment, the composite suture needle 100 may be formed by assembling the sheath 124 onto the reduced-diameter section 118 of the elongate body 102. In one embodiment, the distal end 128 of the sheath 124 preferably abuts the shoulder 112 (FIG. 2B) of the tapered section 108 of the elongate body 102. The inner diameter ID 1 of the sheath 124 preferably is the outer diameter OD 1Slightly larger than (FIG. 2B). The outer surface 132 of the sheath 124 preferably approximates an outer diameter OD at the proximal end 110 of the tapered section 108 of the elongated body 102. 3 (FIG. 3B) is defined.

[0095] In one embodiment, after the sheath 124 is assembled over the reduced diameter section 118 of the elongated body 102, the proximal end 126 of the sheath 124 preferably extends proximally beyond the proximal end 104 of the elongated body 102 to define a suture attachment opening 134 located at the proximal end of the composite suture needle 100. The suture attachment opening 134 is preferably surrounded by a crimp zone 136 of the sheath 124 that can be crimped or crimped to secure the end of the suture to the proximal end of the composite suture needle 100. In one embodiment, the end of a suture (not shown) can be inserted into the suture attachment opening 134 of the sheath 124, and the crimp zone 136 of the sheath 124 can be crimped to secure the end of the suture to the proximal end of the composite suture needle 100.

[0096] Referring to FIGS. 4B-4D, in one embodiment, the sheath 124 has an inner diameter ID of the sheath to apply heat to the sheath to cause it to grip or fit snugly against the outer surface of the reduced diameter section 118. 1 It can be attached to the reduced diameter section 118 of the elongated body 102 by shrinking the size thereof, thereby forming a composite suture needle 100 having a more elastic section. In one embodiment, the more elastic section of the composite suture needle is preferably the section of the composite suture needle where the sheath 124 extends over the reduced diameter section 118.

[0097] In one embodiment, the sheath 124 can be attached to the reduced diameter section 118 of the elongated body 102 by applying an adhesive within a space 138 located between the outer surface of the reduced diameter section 118 and the inner surface of the sheath 124.

[0098] In one embodiment, the sheath 124 can be attached to the reduced diameter section 118 of the elongated body 102 by using a bonding material disposed within a space 138 located between the outer surface of the reduced diameter section 118 and the inner surface of the sheath 124, whereby the bonding material is preferably weldable to both the material (e.g., stainless steel) used to make the elongated body 102 and the material (e.g., nitinol) used to make the sheath 124.

[0099] In one embodiment, the composite suture needle 100 preferably includes a reduced diameter section 118 and a sheath 124 that overlays the reduced diameter section. The length of the elongated body 118 covered by the sheath 124 preferably defines a more elastic region of the composite suture needle 100 designed to bend (e.g., flatten) when passing through a smaller cannula without plastic deformation. The presence of the more elastic region formed by the combination of the reduced diameter section 118 and the highly elastic sheath 124 causes the elongated body 102 of the composite suture needle 100 to preferably return (e.g., spring back) to its normal semi-circular configuration after the composite suture needle 100 is removed from the end of the cannula (e.g., at the surgical site), such that the composite suture needle 100 can be used to suture tissue.

[0100] In one embodiment, the composite suture needles disclosed herein are designed to exhibit elasticity for passing through a smaller cannula (e.g., a 5 mm cannula) without substantial plastic deformation. In one embodiment, the elongated body of the composite suture needle (i.e., the elongated body 102 shown in FIG. 2A) is made of stainless steel such as high strength stainless steel. In one embodiment, by knowing the yield strength and Young's modulus of the stainless steel used to make the elongated body of the composite suture needle, the elongated body can be designed to have a reduced diameter section with a diameter dimension that enables the composite suture needle to be elastically deformed without plastic deformation.

[0101] The yield point of a material is the point on the stress-strain curve that indicates the limit of the elastic behavior of the material and the onset of plastic behavior. Yield strength or yield stress is a material property defined as the stress at which the material begins to plastically deform, and the yield point is the point at which non-linear (elastic + plastic) deformation begins. Prior to the yield point, the material deforms elastically and returns to its original shape when the applied stress is removed. However, once the yield point is passed, some portion of the deformation is permanent and irreversible. The yield point determines the limit of the performance of mechanical components, as it represents the upper limit of the force that can be applied without permanent deformation.

[0102] Young's modulus of a material is one way to measure the elastic modulus of the material. The elastic modulus is a quantity that measures the resistance of an object to elastically (i.e., non-permanently) deform when a stress is applied to it. The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region. A more rigid material will have a higher elastic modulus.

[0103] By specifying a method for measuring stress and strain that includes direction, it becomes possible to define many types of elastic moduli. Young's modulus (E) describes the tendency of an object to deform along its axis when opposite forces are applied along the axis. This is defined as the ratio of tensile stress to tensile strain. This is often simply referred to as the elastic modulus.

[0104] In one embodiment, the elongated body of the composite suture needle is preferably elastically deformable from a semi-circular shape to a flatter shape having a straight section without plastically deforming the elongated body of the composite suture needle. As a result, when the elastic suture needle passes through a smaller cannula and is removed at the surgical site, the elongated body of the composite suture needle preferably springs back to its original semi-circular shape.

[0105] As is known to those skilled in the art, most materials can withstand a moderate amount of strain before plastic deformation. In one embodiment, the sheath 124 is preferably made of a highly elastic material (e.g., nitinol) that can withstand greater strain before plastic deformation compared to a less elastic material (e.g., stainless steel). In one embodiment, the composite suture needle 100 has a neutral axis L N includes a highly elastic material at the maximum distance from (FIG. 4D), which can withstand greater bending before plastic deformation compared to a conventional suture needle made of a single less elastic material (e.g., stainless steel) having uniform elastic properties. This is due to the outer diameter OD of the reduced diameter section 118 of the elongated body 102 1 being smaller than the outer diameter OD of the composite suture needle 100 3 as a result.

[0106] Referring to FIGS. 5A and 5B, in one embodiment, to secure a composite suture needle such as the composite suture needle 100 shown in FIGS. 2A-2B, FIGS. 3A-3B, and FIGS. 4A-4D and described above, a clamping element such as a needle driver 150 can be utilized to remove the composite suture needle from the suture needle package and / or advance the composite suture needle through the lumen of the cannula to position the composite suture needle at the surgical site for performing a suturing operation. In one embodiment, the shape of the elongated body of the composite suture needle can change (e.g., flatten) when the needle driver 150 advances the composite suture needle through the cannula. In one embodiment, the composite suture needle has a semi-circular shape defining a first height H 1 (FIG. 4A), and a more elastic intermediate section that allows the composite suture needle to bend from the semi-circular shape to a more flattened shape. The needle driver 150 at the first height H of the composite suture needle 100 (FIG. 4A) 1When advancing the composite suture needle through a cannula having an inner diameter smaller than that, the inner wall of the cannula can apply an external force to the elongated body of the composite suture needle, whereupon the elongated body of the composite suture needle flattens, or straightens, along the reduced diameter section 118 (FIG. 4B) of the elongated body of the composite suture needle to deform to a smaller second height in order to fit through the smaller inner diameter of the cannula. When removed from the end of the cannula, the inner wall of the cannula no longer applies an external force to the composite suture needle, whereupon the elongated body of the composite suture needle preferably returns (e.g., springs back) to its original semi-circular shape having the first height H 1 (FIG. 4A).

[0107] In one embodiment, the needle driver 150 preferably includes an elongated shaft 152 having a proximal end 154 and a distal end 156 having a clamp assembly 158 movable between an open position and a closed position. In one embodiment, the clamp assembly 158 preferably includes a lower jaw 160 and an opposing upper jaw 162 movable between an open position and a closed position. In one embodiment, with the clamp assembly 158 in the open position, the lower 160 and upper jaws 162 can be guided to align with the tip 116 of the composite suture needle 100 (FIG. 2A). In one embodiment, after the lower and upper jaws are aligned with the tip of the composite suture needle, the jaws can be moved to the closed position to clamp and / or grip the tapered section 108 (FIG. 2A) of the elongated body 102 of the composite suture needle with the tip 116 preferably positioned between and surrounded by the opposing lower and upper jaws.

[0108] Referring to FIG. 5B, in one embodiment, the lower jaw 160 is stationary relative to, fixedly secured to, and / or integral with the distal end 156 of the elongated shaft 152 of the needle driver 150 such that the lower jaw 160 does not move relative to the distal end 158 of the elongated shaft 152 of the needle driver 150. In one embodiment, the lower jaw 160 preferably includes a substantially flat upper surface 164 adapted to be aligned with the tip 116 (FIG. 2A) of the composite suture needle. In one embodiment, the substantially flat upper surface 164 of the lower jaw 160 may include surface roughening, such as knurling, to enhance gripping of the distal end of the composite suture needle when the clamp assembly 158 is in the closed position.

[0109] In one embodiment, the upper jaw 162 of the clamp assembly 158 is pivotally secured to the distal end 156 of the elongated shaft 152 of the needle driver 150, preferably via a pivot 166 that pivotally secures the proximal end of the upper jaw 162 to the distal end 156 of the elongated shaft 152. The upper jaw 162 preferably includes a substantially flat bottom surface 168 that faces the substantially flat upper surface 164 of the lower jaw 160. The substantially flat bottom surface 168 of the upper jaw 162 may include surface roughening, such as knurling, for gripping the distal end of the composite suture needle when the clamp assembly 158 is in the closed position.

[0110] Referring to FIGS. 5A and 5B, in one embodiment, when the lower jaw 160 and the upper jaw 162 are in the closed position to clamp, grip, and / or secure the tapered section 108 of the elongated body 102 of the composite suture needle 100, with the tip 116 of the composite suture needle positioned between the opposing jaws, the upper surface 164 of the lower jaw 160 engages the surface of the tapered section 108 at the distal end 106 of the elongated body 102 of the composite suture needle 100, and the bottom surface 168 of the upper jaw 162 preferably engages another surface of the tapered section 108 of the elongated body 102 at the distal end 106 of the composite suture needle 100. In one embodiment, when the jaws are closed, the upper surface 164 and the bottom surface 168 of the respective lower jaw 160 and upper jaw 162 can be spaced from the tip 116, such that the tip is not damaged, bent, injured, or dulled by the jaws of the clamp assembly. In one embodiment, the closed jaws 160, 162 preferably surround the outer periphery of the tip 116 when the composite suture needle 100 passes through the cannula to prevent the tip from being scratched or damaged by the inner wall of the cannula.

[0111] In one embodiment, the suture needle package can hold one or more composite suture needles, such as the composite suture needle 100 shown in FIGS. 4A - 4D, such that the tip 116 of the suture needle 100 is pre-positioned in a location that facilitates aligning the tip 116 between the upper surface 164 and the bottom surface 168 of the respective lower jaw 160 and upper jaw 162 of the clamp assembly 158 of the needle driver 150.

[0112] Referring to FIG. 6A, in one embodiment, after the clamp assembly 158 of the needle driver 150 is closed to clamp onto the distal end 106 of the elongated body 102 of the composite suture needle 100, the needle driver 150 can be used to advance the suture needle 100 through the cannula 170 to position the suture needle at a surgical site for performing a suturing procedure. In one embodiment, the cannula 170 preferably has a second height H that is less than the first height H 1 (FIG. 4A). 2It has an elongated conduit 172 having an inner diameter that defines it. The elongated conduit 172 preferably extends to an opening 174 at the distal end 176 of the cannula 170. The clamp assembly 158 of the needle driver 150 clamped onto the distal end 106 of the elongated body 102 of the composite suture needle 100 can be advanced toward the distal end of the conduit 172 of the cannula 170 to pull the composite suture needle 100 through the cannula. When the composite suture needle 100 is pulled toward the distal end 176 of the cannula 170 by the clamp assembly 158 of the needle driver 150, the composite suture needle 100 has a second height H 1 (FIG. 4A) that is smaller than the original first height H of the composite suture needle 100. 2 It needs to fit through a smaller conduit 172 having a smaller height. Since the composite suture needle 100 can be elastically deformed in the intermediate section 125, as shown in FIG. 6A, the elongated body 102 of the composite suture needle 100 preferably elastically deforms (e.g., straightens, becomes flatter).

[0113] In FIG. 6A, the more elastic intermediate section 125 of the composite suture needle 100, including the highly elastic sheath 124 (FIGS. 4A - 4D) of the composite suture needle 100, preferably straightens or flattens to reduce the overall height of the composite suture needle to a third height H 2 that is smaller than the second height H of the conduit 172 of the cannula 170. 3 At the smaller third height H 3 the flattened suture needle 100 can be passed through the smaller lumen 172 of the cannula 170. As will be described in more detail herein, the composite suture needle is designed to substantially elastically deform when passing through a smaller cannula, changing from the first height H 1 (FIG. 4A) to the third height H 3 .

[0114] Referring to FIG. 6B, after the composite suture needle 100 is removed from the opening 174 at the distal end 176 of the cannula 170, the composite suture needle 100 preferably has a fourth height H 2 (FIG. 6A) that is larger than the second height H of the conduit 172 of the cannula 170. 4Spring back to the original curved configuration (e.g., semi-circular shape). The surgeon may utilize the semi-circular composite suture needle 100 shown in FIG. 6B to perform a suturing operation at the surgical site.

[0115] In one embodiment, after being removed from the distal end 174 of the cannula 170, the composite suture needle 100 preferably springs back to a fourth height H 1 that substantially coincides with the original first height H of the composite suture needle (FIG. 4A). 4 In one embodiment, the fourth height H 4 is about 90% of the original first height H. 1 In one embodiment, the fourth height H 4 is about 95% of the original first height H. 1 In one embodiment, the fourth height H 1 substantially coincides with the original first height H. 1

[0116] Referring to FIG. 6C, in one embodiment, at the end of the suturing operation, the curved composite suture needle 100 having the fourth height H 4 can be removed from the patient by retracting the composite suture needle through the cannula 170. In one embodiment, the clamp assembly 158 of the needle driver 150 is closed again to fix the tapered section 108 of the elongated body 102 of the curved composite suture needle 100 between the lower jaw 160 and the upper jaw 162 of the needle driver 150.

[0117] Referring to FIG. 6D, in one embodiment, at the completion of the suturing operation, the needle driver 150 preferably retracts the composite suture needle 100 through the conduit 172 of the cannula 170. Since the second height H of the conduit of the cannula is smaller than the fourth height H 2 of the composite suture needle 100 4 (FIG. 6B), the intermediate section 125 of the composite suture needle 100 preferably has a third height H 3Straightens or flattens to the extent that the suture needle can be withdrawn through the conduit 172 of the cannula 170. When the composite suture needle 100 is withdrawn through the cannula 170, the lower jaw 160 and the upper jaw 162 of the needle driver 150 preferably engage with the tapered section 108 of the elongated body 102 of the composite suture needle 100 to protect the tip from being damaged when the needle is pulled and / or retracted through the cannula 170, surrounding the tip 116 (FIG. 4A) of the suture needle.

[0118] Referring to FIGS. 7A-7C, in one embodiment, the composite suture needle 200 preferably includes an elongated body 202 (i.e., the core component) having a proximal end 204 and a distal end 206. In one embodiment, the distal end 206 of the elongated body 202 preferably includes a tapered section 208 having a proximal end 210 that defines a distal shoulder 212 and a distal end 214 that includes a sharp or pointed tip 216. The tapered section 208 preferably tapers inwardly between its proximal end 210 and its distal end 214. In one embodiment, the pointed tip 216 at the distal end 214 of the tapered section 208 preferably defines the leading end of the elongated body 202 designed to pierce tissue to facilitate passage of the distal end 206 of the elongated body 202 through tissue during a suturing procedure.

[0119] In one embodiment, the proximal end 204 of the elongated body includes a larger diameter section having a proximal end 205 adapted to have a suture attachment hole 207 formed therein and a distal end 209 that defines a shoulder 211.

[0120] In one embodiment, the elongated body 202 of the composite suture needle 200 preferably includes a reduced diameter section 218 that extends between a shoulder 211 at the proximal end 204 of the elongated body and a shoulder 212 at the distal end of the elongated body. In one embodiment, the reduced diameter section 218 has a cross-section with a circular shape configured to receive a sheath made of a highly elastic material, as described in more detail herein.

[0121] In one embodiment, the reduced diameter section 218 of the elongated body 202 preferably has an outer diameter OD 4 defining it, and the shoulder 211 at the proximal end of the elongated body has an outer diameter OD 5 defining it, and the shoulder 212 at the distal end of the elongated body also has an outer diameter OD 5 defining it, such that the outer diameter OD 5 of each of the shoulders 211, 212 is greater than the outer diameter OD 4 of the reduced diameter section 218 of the elongated body 202 extending between the shoulders.

[0122] In one embodiment, the elongated body 202 can be curved and / or can have a semi-circular or semi-elliptical shape. In one embodiment, the reduced diameter section 218 of the elongated body 202 is curved and preferably includes a concave surface 220 extending along the inner side of the curve of the reduced diameter section and a convexly curved outer surface 222 extending along the outer side of the curve of the reduced diameter section 218.

[0123] In one embodiment, the elongated body 202 can be made of a strong alloy such as stainless steel. In one embodiment, the stainless steel can include austenitic stainless steel (302SS) and martensitic age-hardened (maraging) stainless steel (455SS).

[0124] Referring to FIGS. 8A and 8B, in one embodiment, the composite suture needle 200 preferably includes a sheath 224 made of a material having a higher level of elasticity than the material used to make the elongated body 202 (FIGS. 7A-7C). In one embodiment, the sheath 224 can be made of a highly elastic material such as nitinol. In one embodiment, the sheath 224 can have a sleeve shape, a tube shape, or a cylindrical shape. In one embodiment, the sheath 224 is preferably sized, shaped, and / or configured to be assembled over the reduced diameter section 218 of the elongated body 102 (FIGS. 7A-7C) to form a composite suture needle 200 that includes an elongated body with relatively low elasticity and a sheath 224 with relatively high elasticity compared to the material used to make the elongated body.

[0125] In one embodiment, the sheath 224 preferably has a proximal end 226, a distal end 228, and a lumen 230 extending from its proximal end 232 to its distal end 234. Referring to FIGS. 7A-7C and 8B, in one embodiment, the lumen 236 of the sheath 224 preferably has an inner diameter ID 4 that is slightly larger than the outer diameter OD 2 of the reduced diameter section 218 of the elongated body 202. In one embodiment, the sheath 224 preferably has an outer diameter OD 5 that approximates the outer diameter OD 6Defines an outer surface 232 and has it. In one embodiment, when the sheath 224 is assembled onto the reduced diameter section 218 of the elongated body to form the composite suture needle 200, the distal end 228 of the sheath 224 preferably abuts against the shoulder 212 at the distal end of the elongated body, and the proximal end 226 of the sheath 224 preferably abuts against the shoulder 211 at the proximal end of the elongated body. In one embodiment, the outer surface 232 at the distal end 228 of the sheath 224 approximates the outer surface at the proximal end 210 of the tapered section 208, providing a smooth transition between the tapered section 208 of the composite suture needle and the sheath 224. The outer surface 232 at the proximal end 226 of the sheath 224 approximates the outer surface at the distal end 209 of the proximal end 204 of the elongated body 202, providing a smooth transition between the proximal end of the sheath and the larger diameter section at the proximal end of the elongated body.

[0126] In one embodiment, when the sheath is assembled with the elongated body to form the composite suture needle, the sheath preferably traverses most of the length of the elongated body.

[0127] Referring to FIGS. 9A and 9B, in one embodiment, the composite suture needle 200 can be formed by assembling the sheath 224 onto the reduced diameter section 218 of the elongated body 202. In one embodiment, the distal end 228 of the sheath 224 preferably abuts against the shoulder 212 (FIG. 8B) at the distal end of the elongated body 202, and the proximal end 226 of the sheath 224 abuts against the shoulder 211 at the proximal end of the elongated body 202. The inner diameter ID 2 (FIG. 8B) of the sheath 224 is preferably slightly larger than the outer diameter OD 4 (FIGS. 7B and 7C) of the reduced diameter section 218 of the elongated body 202. The outer surface 232 of the sheath 224 preferably defines an outer diameter OD 5 (FIG. 7B) that approximates the outer diameter OD 5 (FIG. 7C) at the proximal end 210 of the tapered section 208 of the elongated body 202 and the outer diameter OD 6 (FIG. 8B) at the distal end 209 of the proximal end 204 of the elongated body 202.

[0128] In one embodiment, after the sheath 224 is assembled over the reduced diameter section 218 of the elongate body 202, the proximal end 226 of the sheath 224 preferably abuts a shoulder 211 at the proximal end of the elongate body, and the distal end 228 of the sheath 224 preferably abuts a shoulder 212 at the distal end of the elongate body 202. In one embodiment, the suture receiving aperture 207 is formed at the proximal end 204 of the elongate body 202 for attaching the end of a suture to the proximal end of the composite suture needle.

[0129] Referring to FIG. 9B, in one embodiment, the sheath 224 can be attached to the reduced diameter section 218 of the elongate body 202 by heating the sheath to shrink the size of the inner diameter of the sheath to grip or fit snugly over the outer surface of the reduced diameter section 218, thereby forming a composite suture needle 200 having a more elastic section. In one embodiment, the sheath 224 can be attached to the reduced diameter section 218 of the elongate body 202 by applying an adhesive within a space 238 located between the outer surface of the reduced diameter section 218 and the inner surface of the sheath 224.

[0130] In one embodiment, the sheath 224 can be attached to the reduced diameter section 218 of the elongate body 202 by using a bonding material disposed within a space 238 located between the outer surface of the reduced diameter section 218 and the inner surface of the sheath 224, whereby the bonding material is preferably weldable to both the material (e.g., stainless steel) used to make the elongate body 202 and the material (e.g., nitinol) used to make the sheath 224.

[0131] In one embodiment, the composite suture needle 200 preferably includes a reduced diameter section 218 and a sheath 224 that overlays the reduced diameter section. The length of the elongated body 202 covered by the sheath 224 preferably defines a more elastic region of the composite suture needle 200 that is designed to bend (e.g., flatten) when passing through a smaller cannula without plastic deformation. The presence of the more elastic region formed by the combination of the reduced diameter section 218 and the highly elastic sheath 224 causes the elongated body 202 of the composite suture needle 200 to preferably return (e.g., spring back) to its normal semi-circular configuration after the composite suture needle 200 is removed from the end of the cannula (e.g., at the surgical site), such that the composite suture needle 200 can be used to suture tissue.

[0132] Referring to FIG. 10, in one embodiment, the composite suture needle 300 preferably includes an elongated body 302 (i.e., a core component) having a proximal end 304 and a distal end 306 with a tapered section 308 that terminates at a sharp or pointed tip 316. The tapered section 308 preferably tapers inwardly to the sharp tip 316. The sharp tip 316 preferably defines the leading end of the elongated body 302 adapted to pierce tissue during a suturing procedure.

[0133] In one embodiment, the elongated body 302 preferably defines an outer diameter OD 7 In one embodiment, the elongated body 302 can be curved and / or can have a semi-circular or semi-circular shape. In one embodiment, the elongated body 302 is curved and preferably includes a concave surface 320 that extends along the inner side of the curve of the elongated body and a convexly curved outer surface 322 that extends along the outer side of the curve of the elongated body.

[0134] In one embodiment, the elongated body 302 can be made of a strong alloy such as stainless steel. In one embodiment, the stainless steel can include austenitic stainless steel (302SS) and martensite age hardened (marage) stainless steel (455SS).

[0135] Referring to FIGS. 11A and 11B, in one embodiment, the composite suture needle 300 preferably includes a sheath 324 made of a material having a higher level of elasticity than the material used to make the elongated body 302 (FIG. 10) of the composite suture needle. In one embodiment, the sheath 324 can be made of a highly elastic material such as nitinol. In one embodiment, the sheath 324 can have a sleeve shape, a tubular shape, or a cylindrical shape. In one embodiment, the sheath 324 is preferably sized, shaped, and / or configured to be assembled onto the elongated body 302 (FIG. 10) to form a composite suture needle 300 that includes an elongated body having relatively low elasticity and a sheath 324 having relatively high elasticity compared to the material used to make the elongated body.

[0136] In one embodiment, the sheath 324 preferably has a proximal end 326, a distal end 328 having a tapered outer surface 335, and a lumen 330 extending from its proximal end 326 to its distal end 328. Referring to FIGS. 10 and 11A-11B, in one embodiment, the lumen 330 of the sheath 324 preferably has an inner diameter ID 7 (FIG. 10) that is slightly larger than the outer diameter OD 3 of the elongated body 302. In one embodiment, when the sheath 324 is assembled onto the elongated body 302 to form the composite suture needle 300, the tapered outer surface 335 at the distal end 328 of the sheath 324 preferably approximates the outer surface of the tapered section 308 at the distal end 306 of the elongated body 302 to provide a smooth transition between the distal end 328 of the sheath 324 and the tapered section 308 of the elongated body 302.

[0137] In one embodiment, when the sheath is assembled with the elongated body to form a composite suture needle, the sheath preferably covers most of the length of the composite suture needle. In one embodiment, the sheath is formed around the elongated body and can be presented to the needle manufacturing equipment as a prefabricated composite wire. The needle manufacturing equipment can be used to grind the tip to expose the stainless steel of the elongated body. The proximal end of the elongated body can be drilled, laser drilled, and / or electropolished to create a suture thread receiving hole.

[0138] Referring to FIGS. 12A and 12B, in one embodiment, the composite suture needle 300 can be formed by assembling a sheath 324 over an elongated body 302 (FIG. 10). In one embodiment, a tapered section 335 at the distal end 328 of the sheath 324 preferably overlaps a tapered section 308 at the distal end 306 of the elongated body 302. The inner diameter ID 3 (FIG. 11B) of the sheath 324 is preferably slightly larger than the outer diameter OD 7 (FIG. 10) of the elongated body 302.

[0139] In one embodiment, after the sheath 324 is assembled over the elongated body 302, the sharp tip 316 and the distal portion of the tapered section 308 of the elongated body 302 preferably project beyond a tapered section 335 at the distal end 328 of the sheath 324.

[0140] Referring to FIG. 12B, in one embodiment, the sheath 324 can be attached to the elongated body 302 by applying heat to the sheath to shrink the size of the inner diameter of the sheath to grip or fit snugly against the outer surface of the elongated body 302, thereby forming a composite suture needle 300 having an elastic section. In one embodiment, the sheath 324 can be attached to the elongated body 302 by applying an adhesive in a space 338 located between the outer surface of the elongated body 302 and the inner surface of the sheath 324.

[0141] In one embodiment, the sheath 324 can be attached to the elongated body 302 by using a bonding material disposed within a space 338 located between the outer surface of the elongated body 302 and the inner surface of the sheath 324, whereby the bonding material is preferably weldable to both the material (e.g., stainless steel) used to fabricate the elongated body 302 and the material (e.g., nitinol) used to fabricate the sheath 324.

[0142] In one embodiment, the composite suture needle 300 preferably includes an elongated body 302 and a sheath 224 that overlays the elongated body. The length of the elongated body 302 covered by the sheath 324 preferably defines a more elastic region of the composite suture needle 300 designed to bend (e.g., flatten) when passing through a smaller cannula without plastic deformation. Due to the presence of the more elastic region formed by the combination of the elongated body 302 and the highly elastic sheath 324, after the composite suture needle 300 is removed from the end of the cannula (e.g., at the surgical site), the elongated body 302 of the composite suture needle 300 preferably returns (e.g., springs back) to its normal semi-circular configuration, such that the composite suture needle 300 can be used to suture tissue.

[0143] In one embodiment, after the sheath 324 is assembled onto the elongated body 302, the proximal end 326 of the sheath 324 preferably extends proximally beyond the proximal end 304 of the elongated body 302 to define a suture attachment opening 334 located at the proximal end of the composite suture needle 300. The suture attachment opening 334 is preferably surrounded by a crimping zone 336 of the sheath 324 that can be crimped or pressure-bonded to secure the end of the suture to the proximal end of the composite suture needle 300. In one embodiment, the end of a suture (not shown) can be inserted into the suture attachment opening 334 of the sheath 324, and the crimping zone 336 of the sheath 324 can be crimped to secure the end of the suture to the proximal end of the composite suture needle 300.

[0144] Referring to FIG. 13A, in one embodiment, a composite suture needle 400 having a highly elastic intermediate section 425 preferably includes an elongated body 402 having a proximal end 404 and a distal end 406. The elongated body 402 of the composite suture needle 400 can be curved and can have a semi-circular or semi-elliptical shape.

[0145] In one embodiment, the highly elastic intermediate section 425 is configured to be the highly elastic region of the composite suture needle 400 to allow the composite suture needle to be straightened to pass through a smaller cannula and then returned to its original curved configuration for use in a suturing procedure.

[0146] In one embodiment, the composite suture needle 400 preferably includes a suture attachment barrel 408 adjacent to the proximal end 404 of the elongated body 402 and a suture attachment opening 410 formed in the proximal surface of the suture attachment barrel 408. The end of a surgical suture (e.g., a filamentous element, a thread) can be inserted into the suture attachment opening 410, and the suture attachment barrel 408 can be crimped to fix the end of the surgical suture to the proximal end 404 of the elongated body 402 of the composite suture needle 400.

[0147] In one embodiment, the composite suture needle 400 preferably includes a tip 412 such as a sharp or pointed tip that is integral with the distal end 406 of the elongated body 402 and preferably defines the leading or most distal end of the composite suture needle 400. The tip 412 is preferably sharpened to facilitate piercing tissue during a suturing procedure and passing the distal end 406 of the elongated body 402 of the composite suture needle 400 through the tissue.

[0148] Referring to FIGS. 13A and 13B, in one embodiment, the elongated body 402 preferably includes a proximal body section 420 having a distal end 422, a distal body section 424 having a proximal end 426, and a highly elastic connector 428 interconnecting the distal end 422 of the proximal body section 420 and the proximal end 426 of the distal body section 424. The highly elastic connector 428 may include a mechanical connection structure such as a doubletail-shaped structure for connecting the highly elastic connector to the proximal body section 420 and the distal body section 424. In one embodiment, the highly elastic connector 428 preferably has an outer diameter OD 10 substantially matching the outer diameter OD 9 of the proximal body section 420 and the distal body section 424 to which the highly elastic connector 428 is coupled at its ends.

[0149] In one embodiment, the composite suture needle 400 preferably includes a highly elastic connector 428 having a higher level of elasticity than the material used to form the proximal body section 420 and the distal body section 424 of the elongated body 402 of the composite suture needle 400. In one embodiment, the highly elastic connector 428 may be made of a highly elastic material such as nitinol, and the elongated body 420 including the proximal body section 420 and the distal body section 424 may be made of stainless steel.

[0150] In one embodiment, the highly elastic connector 428 in the intermediate section 425 of the composite suture needle 400 preferably defines a more elastic region of the elongated body 402 designed to bend when passing through a cannula without plastic deformation. The presence of the more elastic intermediate section 425 formed by the highly elastic connector 428 causes the elongated body 402 of the composite suture needle 400 to preferably return (e.g., spring back) to its normal semi-circular configuration after the composite suture needle 400 is removed from the end of the cannula (e.g., at the surgical site), such that the composite suture needle 400 can be used to suture tissue.

[0151] Referring to FIG. 14A, in one embodiment, the composite suture needle 500 may have a structure similar to that shown above in the embodiments of FIGS. 4A-4D, FIGS. 9A-9D, and / or FIGS. 12A-12B. In one embodiment, the composite suture needle 500 preferably includes an elongated body extending from a proximal end 506 having a suture attachment barrel 508 that defines the proximal end of the composite suture needle, and a distal end 510 having a tapered region 512 with a sharp tip 514 that defines the distal end of the composite suture needle 500. In one embodiment, the suture needle 500 preferably includes a bendable or highly elastic region 525 that extends along most of the length of the elongated body.

[0152] Referring to FIG. 14B, in an embodiment, the highly elastic region 525 of the composite suture needle 500 preferably includes an elongated body 502 made of a less elastic material such as stainless steel, and an outer sheath 530 made of a more elastic material such as nitinol that surrounds the elongated body. In one embodiment, the outer surface of the composite suture needle 500 may have the appearance of a normal stainless steel needle.

[0153] In one embodiment, the needles shown in FIGS. 14A and 14B and described above can be deformed from a semi-circular configuration (FIG. 14A) to a bent configuration having a seagull shape. Referring to FIGS. 15A and 15B, in one embodiment, the composite suture needle 500 can be bent along the highly elastic region 525 to provide a needle having a seagull shape configuration. In the seagull shape configuration of FIGS. 15A and 15B, the suture needle 500 preferably has a smaller height or a lower profile than the non-bent configuration of the suture needle shown in FIG. 14A and described above. The highly elastic region 525 is preferably more bendable and less rigid than the proximal end 506 and the distal end 510 of the composite suture needle 500. Thus, the proximal end 506 and the distal end 510 of the composite suture needle preferably maintain their original shape in both the non-bent configuration (FIG. 14A) and the bent configuration (FIGS. 15A and 15B).

[0154] Referring to FIG. 16, in one embodiment, with the highly elastic region 525 of the composite suture needle 500 bent, the suture needle 500 can be passed through the cannula 570 in a state where the suture needle 500 is arranged in a bent, seagull-shaped configuration. In FIG. 16, the bent composite suture needle 500 having a seagull-shaped configuration has a height H smaller than the inner diameter ID of the lumen 572 of the cannula 570. As a result, the bent composite suture needle 500 can be easily passed through the length of the cannula to reach the surgical site without damaging the needle or creating a non-safe state for the patient. 4 smaller than 5 which defines, such that the bent composite suture needle 500 can be easily passed through the length of the cannula to reach the surgical site without damaging the needle or creating a non-safe state for the patient.

[0155] Referring to FIGS. 17A - 17C, in one embodiment, a composite suture needle 600 having a structure similar to that shown and described above in FIGS. 4A - 4D, FIGS. 9A - 9D, and / or FIGS. 12A - 12B can include an elongated body 602 having a proximal end 606 and a distal end 610 with a sharp tip 614. The composite suture needle 600 preferably includes a highly elastic region 625 having a stainless steel core and a more elastic outer sheath, thereby enabling the elongated body 602 to be bent such that the tip 614 is adjacent to the proximal end 606 of the elongated body.

[0156] In the bent configuration shown in FIGS. 17A - 17C, the composite suture needle 600 can be passed through a cannula to the surgical site. When the suture needle 600 reaches the surgical site, the surgeon can use a surgical tool to deform the bent suture needle into an unbent semi-circular configuration (e.g., the embodiment of FIG. 14A) as illustrated and described herein. When the suturing operation is completed at the surgical site, the surgeon can bend the composite suture needle 600 again in the highly elastic region 625 to reduce the size of the needle and remove the suture needle from the surgical site through the cannula.

[0157] In one embodiment, the elongated body of the elastic suture needle may have a bendable region provided thereon that facilitates changing the shape and / or configuration of the suture needle to fit through a cannula (e.g., a 5 mm cannula), as disclosed in U.S. Patent Application No. 16 / 282,604, filed on February 22, 2019, and U.S. Patent Application No. 16 / 282,652, filed on February 22, 2019, both by the same applicant, the disclosures of which are incorporated herein by reference.

[0158] The above description relates to embodiments of the present invention, but other and further embodiments of the present invention may be devised without departing from the basic scope of the present invention, and the scope of the present invention is limited only by the scope of the following claims. For example, in the present invention, any of the features shown in any of the embodiments described herein or incorporated herein by reference may be incorporated with any of the features shown in any of the other embodiments described herein or incorporated herein by reference and is still intended to be included within the scope of the present invention.

[0159] 〔Embodiment〕 (1) A composite suture needle, comprising: an elongated body having a proximal end and a distal end with a sharp tip; a sheath overlapping the elongated body, the sheath including a material that is more elastic than the elongated body, the sharp tip extending distally beyond the distal end of the sheath; a composite suture needle. (2) The composite suture needle according to embodiment 1, wherein the sheath includes a highly elastic material and the elongated body includes stainless steel. (3) The composite suture needle according to embodiment 2, wherein the highly elastic material includes nitinol. (4) The stainless steel is selected from the group of stainless steels consisting of austenitic stainless steel, martensite-aged (maraging) stainless steel, and stainless steel sold under the registered trademark ETHALLOY® Needle Alloy, the composite suture needle according to Embodiment 2. (5) The elongated body has a reduced diameter section defining a first outer diameter, and the distal end of the elongated body defines a second outer diameter that is larger than the first outer diameter of the reduced diameter section, the composite suture needle according to Embodiment 1.

[0160] (6) The distal end of the elongated body includes a tapered section having a proximal end including a shoulder defining the second outer diameter, the tapered section having a distal end including the pointed tip, the composite suture needle according to Embodiment 5. (7) The sheath has a proximal end, a distal end, and a lumen extending from the proximal end to the distal end of the sheath, the reduced diameter section of the elongated body being disposed within the lumen of the sheath, the lumen of the sheath having an inner diameter that is greater than or equal to the first outer diameter of the reduced diameter section of the elongated body, the composite suture needle according to Embodiment 6. (8) The sheath has an outer surface defining a third outer diameter that approximates the second outer diameter of the shoulder at the proximal end of the tapered section of the elongated body, the composite suture needle according to Embodiment 7. (9) The elongated body and the sheath are curved, the composite suture needle according to Embodiment 1. (10) A composite suture needle, an elongated body having a curved proximal body section, a curved distal body section, and a curved intermediate section extending between the curved proximal body section and the curved distal body section, a sheath overlapping the curved intermediate section of the elongated body, the curved intermediate section of the elongated body including a first material, the sheath including a second material having a higher elasticity than the first material of the curved intermediate section, a sheath A composite suture needle comprising

[0161] (11) The composite suture needle according to embodiment 10, wherein the curved intermediate section and the sheath overlapping the curved intermediate section define a flexible region of the composite suture needle that is more elastic than the curved proximal body section and the curved distal body section of the elongated body of the composite suture needle. (12) The composite suture needle according to embodiment 10, wherein the curved intermediate section of the elongated body comprises stainless steel and the sheath overlapping the curved intermediate section comprises nitinol. (13) The composite suture needle according to embodiment 10, wherein the sheath has a proximal end, a distal end, and a lumen extending from the proximal end to the distal end of the sheath, and the curved intermediate section of the elongated body is disposed within the lumen of the sheath. (14) The composite suture needle according to embodiment 13, wherein the curved intermediate section of the elongated body has a first outer diameter and the lumen of the sheath has a first inner diameter that is greater than or equal to the first outer diameter of the curved intermediate section of the elongated body. (15) The composite suture needle according to embodiment 14, wherein the distal end of the curved proximal section and the proximal end of the curved distal section of the elongated body define a second outer diameter, and the sheath has an outer surface defining a third outer diameter that approximates the second outer diameter.

[0162] (16) The composite suture needle according to embodiment 10, wherein the proximal body section of the elongated body comprises a proximal end face and a suture receiving hole formed in the proximal end face, and the curved distal body section of the elongated body comprises a tissue piercing point at the distal end of the curved distal body section. (17) The composite suture needle according to embodiment 10, wherein the sheath is attached, adhered, or welded to the curved intermediate section of the elongated body via a thermal shrink fit process. (18) A composite suture needle comprising a curved proximal body section made of stainless steel, and a curved distal body section made of stainless steel, and a connector interconnecting the curved proximal body section and the curved distal body section, the connector comprising a material having higher elasticity than the stainless steel of the curved proximal body section and the curved distal body section. A composite suture needle comprising the above. (19) The composite suture needle according to embodiment 18, wherein the connector interconnects a distal end of the curved proximal body section with a proximal end of the curved distal body section. (20) The composite suture needle according to embodiment 19, wherein the connector comprises a doubletail structure for connection to the distal end of the curved proximal body section and the proximal end of the curved distal body section.

[0163] (21) The composite suture needle according to embodiment 18, wherein the connector has an outer diameter approximating an outer diameter of a distal end of the curved proximal body section of the composite suture needle and an outer diameter of a proximal end of the curved distal body section.

Claims

**Claim 1** A composite suture needle, comprising an elongated body extending from a proximal end to a distal end, the elongated body including a distal portion having a tip pointed at the distal end of the distal portion and a reduced-diameter section having a first outer diameter, the distal portion of the elongated body including a shoulder at the proximal end of the distal portion, the shoulder having a second outer diameter larger than the first outer diameter of the reduced-diameter section, and the entire elongated body having a partial circular shape; a sheath overlapping on the reduced-diameter section of the elongated body, the sheath including a material more elastic than the material of the elongated body, the sheath extending along the elongated body on the proximal side of the distal portion such that the distal end of the sheath abuts against the shoulder of the distal portion of the elongated body, and the pointed tip extending distally beyond the distal end of the sheath; and a composite suture needle comprising the above. **Claim 2** The elongated body and the sheath are curved, and a longitudinal axis is defined along the curved elongated body and the curved sheath, the shoulder has a cross-section perpendicular to the longitudinal axis, and the distal end of the sheath abuts against the cross-section in a direction along the longitudinal axis. The composite suture needle according to claim 1. **Claim 3** The composite suture needle according to claim 2, wherein the sheath is fixed around the reduced-diameter section of the elongated body so as to abut against the shoulder. **Claim 4** The distal portion of the elongated body includes a tapered section having a proximal end including the shoulder defining the second outer diameter, the tapered section having a distal end including the pointed tip. The composite suture needle according to claim 3. **Claim 5** The sheath has a proximal end, a distal end, and a lumen extending from the proximal end to the distal end of the sheath, the reduced-diameter section of the elongated body being disposed within the lumen of the sheath, and the lumen of the sheath having an inner diameter greater than or equal to the first outer diameter of the reduced-diameter section of the elongated body. The composite suture needle according to claim 4. **Claim 6** The distal end of the sheath has an outer surface defining a third outer diameter approximating the second outer diameter of the shoulder at the proximal end of the distal portion of the elongated body. The composite suture needle according to claim 5. **Claim 7**: The composite suture needle according to claim 6, wherein the elongated body further has a second shoulder at the distal end of the proximal portion of the elongated body. **Claim 8**: The composite suture needle according to claim 7, wherein the proximal end of the sheath abuts against the second shoulder. **Claim 9**: The composite suture needle according to claim 8, wherein the outer surface at the proximal end of the sheath approximates the outer surface at the distal end of the proximal portion of the elongated body. **Claim 10**: The composite suture needle according to claim 9, wherein the second shoulder has a second cross-section perpendicular to the longitudinal axis, and the proximal end of the sheath abuts against the second cross-section in a direction along the longitudinal axis. **Claim 11**: The composite suture needle according to claim 10, wherein the sheath is fixed to abut against the shoulder and the second shoulder around the reduced-diameter section of the elongated body. **Claim 12** The composite suture needle according to claim 1, wherein the sheath contains a highly elastic material and the elongated body contains stainless steel. **Claim 13** **Claim 14**: The composite suture needle according to claim 12, wherein the highly elastic material contains nitinol. **Claim 15** The composite suture needle according to claim 12, wherein the stainless steel is selected from the group of stainless steels consisting of austenitic stainless steel, maraging stainless steel, and stainless steel sold under the registered trademark ETHALLOY (registered trademark) Needle Alloy.

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