Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
DETACHABLE RETRIEVAL ASSEMBLY AND SYSTEM FOR STONE RETRIEVAL
2. APPLICANT:
Meril Corporation (I) Private Limited, an Indian company of the address Survey No. 135/139, Muktanand Marg, Bilakhia House, Pardi, Vapi, Valsad-396191 Gujarat, India.

The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF INVENTION
[001] The present disclosure relates to a medical device. More particularly, the present disclosure relates to a medical device for retrieving a stone from a body vasculature.
BACKGROUND OF INVENTION
[002] A retrieval assembly is generally used for retrieving one or more stones from within a body vasculature such as the kidney, urinary tract, gall bladder, etc. A retrieval assembly is generally used through an endoscope or a laparoscope. Traditional retrieval assemblies are typically constructed using either a laser-cut or a braided design, each has advantages and disadvantages. Laser-cut baskets are known for their structural strength, but they can be rigid, which makes it difficult to navigate through complex anatomical pathways. In contrast, braided baskets offer greater flexibility, allowing for easier navigation. However, this flexibility may compromise grip stability, potentially reducing the effectiveness of stone capture in certain clinical applications.
[003] Most conventional retrieval assemblies are constructed entirely from shape-memory alloys, which, while offering improved flexibility, still lack the structural adaptability needed for a broad range of clinical applications. Furthermore, conventional retrieval assemblies often lack a detachable mechanism, restricting the ability to interchange retrieval assembly sizes during procedures, thereby limiting procedural versatility.
[004] Therefore, there is a need for a retrieval assembly for retrieving stones and an associated deployment system that overcomes the challenges above.
SUMMARY OF INVENTION
[005] The present invention relates to a stone retrieval assembly. The retrieval assembly includes a basket and a plurality of braided elements. The basket includes a central element provided at a distal end of the retrieval assembly, and a plurality of curved struts extending from the central element. Each curved strut has a distal end coupled to the central element and a proximal end that includes a ring. A cover surrounds an outer surface of the plurality of curved struts. Each braided elements are coupled to the corresponding ring at the proximal end of a curved strut. The proximal ends of the plurality of curved struts are configured to move outwards once unsheathed, causing the basket to expand. The braided elements are configured to restrict the expansion of the curved struts.
[006] Further, the present invention discloses a deployment system for deploying a retrieval assembly. The deployment system includes an outer shaft, an inner shaft and a control element. The inner shaft is at least partially disposed within the outer shaft and removably coupled to a jacket of the retrieval assembly. The control element is coupled to one of the outer shaft or the inner shaft. The control element is configured to be in one of an actuated state or an unactuated state. In the unactuated state, the outer shaft is configured to cover the inner shaft and the retrieval assembly completely. In the actuated state, the outer shaft is configured to expose the retrieval assembly from the inner shaft.
[007] The foregoing features and other features as well as the advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
[008] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[009] Fig. 1A and Fig. 1B depict a perspective view of a retrieval assembly 100, in accordance with an embodiment of the present invention.
[0010] Fig. 2A- Fig. 2C depict a perspective view of a basket 110 of the retrieval assembly 100, in accordance with an embodiment of the present invention.
[0011] Fig. 3 depicts a perspective view of a braided element 120 of the retrieval assembly 100, in accordance with an embodiment of the present invention.
[0012] Fig. 4A and Fig. 4B depict a perspective view of a jacket 130 of the retrieval assembly 100, in accordance with an embodiment of the present invention.
[0013] Fig. 5A depicts a perspective view of a deployment system 200, in accordance with an embodiment of the present invention.
[0014] Fig. 5B depicts an exploded view of the deployment system 200, in accordance with an embodiment of the present invention.
[0015] Fig. 5C depicts a cross-sectional view of the deployment system 200, in accordance with an embodiment of the present invention
[0016] Fig. 6 depicts an assembled view of the deployment system 200 without a handle 600, in accordance with an embodiment of the present invention.
[0017] Fig. 7 depicts a perspective view of an outer shaft 300 of the deployment system 200, in accordance with an embodiment of the present invention.
[0018] Fig. 8 depicts a perspective view of an inner shaft 400 of the deployment system 200, in accordance with an embodiment of the present invention.
[0019] Fig. 8A depicts a perspective view of a protrusion 402 of the inner shaft 400 with the jacket 130, in accordance with an embodiment of the present invention.
[0020] Fig. 9 depicts a perspective view of a control element 500 of the deployment system 200, in accordance with an embodiment of the present invention.
[0021] Fig. 10 depicts a perspective view of the handle 600 of the deployment system 200, in accordance with an embodiment of the present invention.
[0022] Fig. 11 depicts a flowchart of a method 700 for using the deployment system 200 for stone retrieval, according to an embodiment of the present disclosure.
[0023] Fig. 12A-12C depicts various stages during the retrieval of the stone 20 using the deployment system 200, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0025] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0026] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed deployment system, method, and apparatus can be used in combination with other deployment systems, methods, and apparatuses.
[0027] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0028] The present disclosure relates to a detachable stone retrieval assembly (hereinafter, retrieval assembly). The retrieval assembly is designed for minimally invasive procedure relating to removal of kidney and/or ureteral stones. The retrieval assembly is engineered to enhance flexibility and adaptability during a stone retrieval procedure. The retrieval assembly includes a basket and a braided element. In an embodiment, the basket is constructed using a laser-cut technique while the proximal portion includes a braided design, combining the advantages of both structural designs. This hybrid construction provides an optimal balance between strength and flexibility, ensuring efficient stone capture while minimizing tissue trauma. The basket features a smooth, atraumatic surface, reducing the risk of a vascular or tissue injury during retrieval. Additionally, the laser-cut structure enhances safety by eliminating sharp edges that could otherwise cause damage. The braided element significantly enhances flexibility and/or adaptability, allowing the basket to navigate tortuous anatomical pathways while securely capturing stones. Furthermore, the combination of the laser cutting and braiding techniques for making the retrieval assembly, ensure durability and reliability, making the retrieval assembly an effective solution for various stone retrieval procedures.
[0029] Unlike conventional retrieval assembly that includes a pointed tip, the tipless design of the retrieval assembly of the present invention maximizes the capture area. Thus, improving retrieval efficiency while minimizing trauma to surrounding tissues.
[0030] The retrieval assembly further includes a jacket mechanism that enables attachment and detachment from a deployment system. The present disclosure introduces a deployment system specifically designed for the controlled insertion and deployment of the retrieval assembly. The deployment system of the present disclosure is used for the deployment of the retrieval assembly of different sizes. The ability to interchange retrieval assembly using a single deployment system enhances procedural efficiency, reduces the need for multiple devices, and ultimately lowers costs while improving workflow in clinical applications.
[0031] Now referring to figures, Fig. 1A and Fig. 1B depict perspective views of a retrieval assembly 100, in accordance with an embodiment of the present invention. The retrieval assembly 100 has a proximal end 100a and a distal end 100b. In an embodiment, the retrieval assembly 100 includes a basket 110, a braided element 120 and a jacket 130. In an embodiment, the retrieval assembly has a semi-circular structure as shown in Fig. 2B, though the contour of the retrieval assembly 100 of the present invention may take a variety of shapes. Other shapes of the retrieval assembly include without limitation, circular, oval, etc.
[0032] Fig. 2A and Fig. 2B depict a perspective view of a basket 110 of the retrieval assembly 100, in accordance with an embodiment of the present invention. The basket 110 is positioned towards the distal end 100b of the retrieval assembly 100. The basket 110 may be made of a material, including, without limitation, nitinol, stainless steel, platinum, tungsten, etc. or any other biocompatible, shape-memory (self-expanding) material. In an example implementation, the basket 110 is made of nitinol. In an embodiment, the basket 110 is made from a single tube using a laser cutting technique, though any other suitable technique may be used in construction of the basket 110. Thus, the basket 110 made of shape memory materials allows the retrieval assembly 100 to self-expand upon deployment. For example, the basket 110 may be deformed to the collapsed state to load the retrieval assembly 100 over a suitable deployment system. In other words, in the collapsed state, the basket 110 is collapsed, reducing the profile of the retrieval assembly 100 for minimal invasive deployment/retrieval. The collapsible nature allows the basket 110 to remain crimped while the retrieval assembly 100 passes through the narrow deployment system. Upon deployment of the retrieval assembly 100 to a target site, the basket 110 is configured to regain its expanded state. The basket 110 expands to adapt and conform to the surrounding tissues during the deployment without compromising its mechanical strength and structural integrity.
[0033] The basket 110 has a first end 110a and a second end 110b. In an embodiment, the basket 110 includes a cover 10, a central element 112 and a plurality of curved struts 114. The cover 10 encloses the basket 110 to form a pocket towards the distal end 100b of the retrieval assembly 100 (shown in Fig. 1). The cover 10 facilitates effective stone capture. The cover 10 may be a mesh, net, sweep, etc. In an embodiment, the cover 10 at the basket 110 is a mesh that forms the pocket. The mesh of the cover 10 may be constructed from a flexible material, including, without limitation, nylon, nitinol, polypropylene, etc. In an embodiment, the cover 10 is made of nitinol. The cover 10 includes a plurality of pores (hereinafter, pores). The pores in the cover 10 are configured to permit passage of fluid while the capturing stones.
[0034] The central element 112 is provided at the first end 110a, towards a central axis (A) of the retrieval assembly 100. The first end 110a aligns with the distal end 100b of the retrieval assembly 100. The central element 112 serves as a connection hub for the plurality of curved struts 114. The central element 112 helps in forming a tipless connection for the curved struts 114, thereby reducing the risk of trauma during retrieval. The central element 112 may include a central lumen 112a to make the distal end 100b tipless. The central element 112 may have a pre-defined shape, such as without limitation, O-shaped, oval-shaped, etc. The diameter of the central element 112 may be in the range of 0.4 and 1.0 mm. In an exemplary embodiment, the diameter of the central element 112 is 1.0 mm.
[0035] The plurality of curved struts 114 (hereinafter, curved struts 114) of the basket 110 extends outwardly from the central element 112. Each curved strut 114 has a distal end and a proximal end. The curved struts 114 may be co-planar or slanted towards the second end 110b. The curved struts 114 are curved towards the second end 110b to form a predefined shape or structure of the basket 110. The curved struts 114 of the basket 110 are configured to expand to form the predefined shape of the basket 110, including, but not limited to, U-shape, C-shape, convex shape, concave shape, sinusoidal shape, etc. In an embodiment, the curved struts 114 are curved to form a convex shape of the basket 110. The convex shape of basket 110 is configured to conform to the anatomical structure of the surrounding tissues, thus eliminating the risk of trauma to tissues during deployment. The cover 10 surrounds an outer surface of the plurality of curved struts 114.
[0036] The curved struts 114 are configured to expand and collapse. The proximal ends of the plurality of curved struts 114 are configured to move outwards once unsheathed, causing the basket 110 to expand. The shape memory property of the basket 110 allows the curved struts 114 to revert to their original shape upon release of external force, ensuring optimal performance. The curved struts 114 may be distributed uniformly or non-uniformly and positioned at pre-defined distances from each other. The number and dimensions of curved struts 114 may be chosen based upon requirements. In an embodiment, the basket 110 may include between 3 and 8 curved struts 114. In an embodiment, the basket 110 includes four curved struts 114.
[0037] In the expanded state, the curved struts 114 include an angle of curvature, a radius of curvature and spacing between two adjacent curved struts 114, as shown in Fig. 2C. Each curved strut 114 forms the curvature at an angle of curvature (θ), defined as the angle between the tangent at the origin of the curve and the tangent at the second end 110b of the basket 110. The curvature at an angle of curvature θ may range between 30° and 120°. In an embodiment, the angle of curvature θ is 60°. The curved strut 114 has a radius of curvature (R), which is the distance from the central axis (A) to the second end 110b of the curved strut 114. The radius of curvature (R) may vary depending on the design requirements and the mechanical properties of the material used. In an embodiment, the radius of curvature (R) may range between 3 mm and 5 mm. In an example implementation, the radius of curvature (R) is 4 mm. The spacing between two adjacent curved struts 114 (S) may be uniform or non-uniform and is chosen to ensure optimal expansion and retrieval functionality. The spacing between two adjacent curved struts 114 (S) may range from 4 mm to 10 mm. In an embodiment, the spacing S is 9.4 mm.
[0038] The curved struts 114 are designed with a predefined thickness and width, chosen based on mechanical properties of the material of the basket 110. The length and width of each strut 114 are in a range of 3 to 6mm and 0.03 to 0.10 mm, respectively. In an embodiment, the length and width of each strut 114 are 6 mm and 0.07 mm, respectively. Each curved strut 114 includes a ring 114a at the proximal end of the curved strut 114. Each of the curved struts 114 has the ring 114a at the second end 110b. The ring 114a has a lumen 114b. The lumen 114b is coupled to the braided element 120, which has been explained later.
[0039] The plurality of braided elements 120 extends proximally from the basket 110 to the proximal end 100a of the retrieval assembly 100, as shown in Fig. 1B. Fig. 3 depicts a portion of the braided element 120, according to an embodiment of the present disclosure. The retrieval assembly 100 may include 1 to 4 number of braided elements 120. In an embodiment, the retrieval assembly 100 includes 2 braided elements 120. The braided elements 120 are configured to expand and collapse with the curved struts 114 of the basket 110. In an embodiment, the number of braided elements 120 is 2.
[0040] Each braided element 120 includes a plurality of filaments 122. In an embodiment, plurality of filaments 122 are braided to form a lattice-like structure. Each filament 122 may be made of same or different material. The filaments 122 may be made of material such as without limitation, stainless steel, platinum tungsten, nitinol, etc. In an embodiment, each filament 122 is made of same material i.e., nitinol. The filaments 122 may be arranged in a uniform or non-uniform crossing pattern. The braiding of the filaments 122 ensures an even distribution of forces along the retrieval assembly 100 during expansion and collapse of the retrieval assembly 100. In an embodiment, the filaments 122 are arranged in a uniform crossing pattern. The number of filaments 122 in one braided element 120 may be in the range of 2 to 4. In an exemplary embodiment, each braided element 120 consists of four filaments 122. The length of the filaments 122 may be in a range of 6 to 12 mm. In an embodiment, the length of the filaments 122 is 12 mm.
[0041] Each braided element 120 is coupled to the ring 114a of the respective curved struts 114. In an embodiment, each braided element 120 passes through two adjacent rings 114a of the curved struts 114. After passing through the rings 114a, each end of the braided element 120 is coupled to the jacket 130. Alternately, each braided element 120 may pass through alternate rings 114a of the curved struts 114.
[0042] The braided elements 120 allow for expansion of the basket 110 during stone retrieval. For example, in the collapsed state of the retrieval assembly 100, the braided elements 120 are configured to relax. And, upon expansion of the retrieval assembly 100, the braided elements 120 are configured to restrict expansion of the curved struts 114 of the basket 110 to acquire a convex shape of the basket 110. Thereby, ensuring structural integrity of the retrieval assembly 100. In an embodiment, the length of the braided element 120 determines a maximum expansion of the curved struts 114 of the basket 110.
[0043] Fig. 4A and Fig. 4B depict a perspective view of a jacket 130 of the retrieval assembly 100, in accordance with an embodiment of the present invention. The jacket 130 is positioned at the proximal end 100a of the retrieval assembly 100. The jacket 130 is configured to removably couple the retrieval assembly 100 to a deployment system. Different sizes of the retrieval assembly 100 may be coupled to jacket 130. The jacket 130 serves as a secure connection interface, ensuring a stable attachment while also permitting easy detachment when required. The jacket 130 may have a shape, such as, without limitation, cuboidal, cylindrical, etc. In an embodiment, the jacket 130 is cylindrical in shape. The jacket 130 may be made of a biocompatible material including, without limitation, stainless steel, tungsten, etc. In an example implementation, the jacket 130 is made of stainless steel.
[0044] The jacket has a first end and a second end. A portion towards the first end of the jacket 130 includes a cavity 132. The cavity 132 extends for a partial length of the jacket 130. The cavity 132 is configured to accommodate a free ends the braided element 120 of the braided element 120. In other words, the braided elements 120 are coupled to the cavity 132. The braided element 120 may be coupled to the cavity 132 using techniques, such as, without limitation, press-fitting, adhesive bonding, threaded coupling, Interference fit, etc. In an embodiment, the braided elements 120 are coupled to the cavity 132 using welding process .
[0045] A portion towards the second end of the jacket 130 is provided with a jacket lumen 134. A width of the jacket lumen 134 is narrower than a width of the cavity 132 towards the first end. The jacket lumen 134 runs along the remaining length of the jacket 130. The jacket lumen 134 may be either threaded or plain, based on the coupling mechanism. The jacket lumen 134 is coupled to the deployment system. In an embodiment, the jacket lumen 134 has a plurality of inner threads 134a. The plurality of inner threads 134a facilitate a secure and removable coupling between the retrieval assembly 100 and the deployment system. The inner threads 134a facilitate easy detachment and replacement of the retrieval assembly 100 without requiring a new deployment system.
[0046] Fig. 5A depicts a perspective view and Fig. 5B depicts an exploded view of a deployment system 200, in accordance with an embodiment of the present invention. The deployment system 200 has a proximal end 200a and a distal end 200b. In an embodiment, the deployment system 200 includes an outer shaft 300, an inner shaft 400, a control element 500, and a handle 600. The deployment system 200 is used to maneuver the basket to the target site and help in deployment of the basket like the retrieval assembly 100. The deployment system 200 may be used for the basket 110 having various sizes.
[0047] The inner shaft 400 is disposed in the outer shaft 300. The inner shaft 400 secures the retrieval assembly 100, ensuring precise placement for its retrieval. As shown in the Fig. 5C and Fig. 6, the outer shaft 300 is coupled to the control element 500. The control element 500 is positioned towards the proximal end 200a of the deployment system 200. The control element 500 allows a user to control the movement of the outer shaft 300 to expand or collapse the retrieval assembly 100, explained later.
[0048] Fig. 7 depicts a perspective view of an outer shaft 300 of the deployment system 200, in accordance with an embodiment of the present invention. The outer shaft 300 has a proximal end 300a and a distal end 300b. The outer shaft 300 facilitates the radial expansion and collapse of the retrieval assembly 100, explained later. A proximal portion of the outer shaft 300 is disposed in the handle 600 at the proximal end 300a. The outer shaft 300 has an elongated, tubular structure and includes an outer lumen 300c. The outer lumen 300c accommodates the inner shaft 400 and the retrieval assembly 100. The outer shaft 300 applies a constraining force on the retrieval assembly 100, ensuring the curved struts 114 of the retrieval assembly 100 remain in a collapsed state. The length of the outer shaft 300 may be chosen based upon procedural requirements. An inner diameter of the outer shaft 300 may correspond to an outer diameter of the inner tube 400.
[0049] In an embodiment, the length of the outer shaft 300 may range between 900 mm and 1200 mm, the outer diameter of the outer shaft 300 may range between 0.7 mm and 1.3 mm, and the inner diameter of the outer shaft 300 may range between 0.4 mm and 1 mm. In an example implementation, the length, the outer diameter and the inner diameter of the outer shaft 300 are 1200 mm, 1.3 mm and 1 mm, respectively. The outer shaft 300 may be made of a biocompatible material, including, without limitation, polyether block amide (Pebax), polymide, etc. In an example implementation, the outer shaft 300 is made of Pebax. The outer shaft 300 may be a catheter or an introducer sheath.
[0050] The outer shaft 300 includes a stem 302 towards the proximal end 300a. The stem 302 extends perpendicularly from the outer shaft 300. The stem 302 is coupled to the control element 500. The outer shaft 300 is configured to move axially in response to an actuation input received by the control element 500. The stem 302 may have a pre-defined shape such as cuboidal, cylindrical, conical, elliptical, etc. In an embodiment, the stem 302 has a hollow cylindrical structure and includes a stem lumen 302a. At least a portion of the stem lumen 302a receives the control element 500. The length and outer diameter of the stem 302 may range from 5 mm to 8 mm and 3 mm to 5 mm, respectively. In an embodiment, the length and outer diameter of the stem 302 are 8 mm and 5 mm, respectively. The inner diameter of the stem 302 may be designed according to the size of the control element 500.
[0051] Fig. 8 depicts a perspective view of an inner shaft 400 of the deployment system 200, in accordance with an embodiment of the present invention. The inner shaft 400 has a proximal end 400a and a distal end 400b. The inner shaft 400 extends longitudinally and has an elongated body. The inner shaft 400 is at least partially disposed in the outer lumen 300c of the outer shaft 300. In an embodiment, the inner shaft 400 has a substantially cylindrical body, though it may have any other suitable shape. The inner shaft 400 may have a solid or hollow core for at least a partial length of the inner shaft 400. In an embodiment, the inner shaft 400 has a solid core for the entire length of the inner shaft 400.
[0052] The proximal end 400a of the inner shaft 400 is at least partially disposed in the handle 600. The distal end 400b of the inner shaft 400 is removably coupled to the jacket 130 of the retrieval assembly 100. The inner shaft 400 has a protrusion 402 to couple the jacket 130 of the retrieval assembly 100 with the inner shaft 400. The protrusion 402 may be either threaded or plain, corresponding to the coupling mechanism used in the jacket lumen 134 of the jacket 130. In an embodiment, the protrusion 402 has a plurality of outer threads used to removably couple the inner threads 134a of the jacket 130 of the retrieval assembly 100 to the inner shaft 400 as shown in Fig. 8A. The dimensions of the inner shaft 400 may be chosen based upon procedural requirements. In an embodiment, the length of the inner shaft 400 may range between 880 mm and 1180 mm, and the diameter of the inner shaft 400 may range between 0.3 mm and 0.9 mm. In an example implementation, the length and the diameter of the inner shaft 400 are 1180 mm, and 0.9 mm, respectively. The inner shaft 400 may be made of a biocompatible material, including, without limitation, stainless steel, nitinol, tungsten, etc. In an example implementation, the inner shaft 400 is made of stainless steel.
[0053] The control element 500 is coupled to the outer shaft 300 and facilitates the axial movement of the outer shaft 300. The control element 500 is configured to move the outer shaft 300 axially and trigger the retrieval assembly 100 to be in the expanded state or the collapsed state. In response to the actuation input received by the control element 500, the outer shaft 300 is configured to move axially and expose the inner shaft 400 along with the retrieval assembly 100. The control element 500 may be a sliding button, a roller, or the like.
[0054] Fig. 9 depicts a perspective view of a control element 500 of the deployment system 200, in accordance with an embodiment of the present invention. In the depicted embodiment, the control element 500 is a sliding button. The control element 500 is slidably disposed within the handle 600. The control element 500 includes a first portion 502, a second portion 504 and a third portion 506. The first portion 502 is positioned at a top end of the control element 500. The third portion 506 is positioned at a bottom end of the control element 500. The second portion 504 extends between the first portion 502 and the third portion 506. The first portion 502 allows the user to hold and manipulate the control element 500. In an embodiment, the first portion 502 includes a grip 502a. The grip 502a may have multiple parallel ridges provided on its top surface, that facilitates a better grip for the user and allows easier manipulation of the control element 500. It should be understood that the top surface of the grip 502a may have other features, such as, grooves, undulations, or the like, instead of, or in addition to, the ridges. The first portion 502 protrudes out of the handle 600. The first portion 502 may have a shape, such as, without limitation, cuboidal, cylindrical, etc. In an embodiment, the first portion 502 is a semi-cylinder.
[0055] The second portion 504 extends vertically downwards from the first portion 502, forming a T-shaped structure. The second portion 504 is at least partially disposed in the handle 600. The second portion 504 may have a shape, such as, without limitation, tapered, cuboidal, cylindrical, etc. In an embodiment, the second portion 504 is tapered with a reduced circumference towards the third portion 506. In one embodiment, the second portion 504 and the third portion 506 may be separate components and may be coupled using any suitable technique. In another embodiment, the second portion 504 and the third portion 506 may form an integrated structure.
[0056] While the depicted embodiment includes the control element having a first portion, a second portion and a third portion, where the first portion includes the grip and the second portion tapers towards the third portion, a person skilled in the art will appreciate that numerous variations to the shape of the control element can be made while practicing the inventive features of the present disclosure and the same are within the scope of the present disclosure.
[0057] The third portion 506 resides within the handle 600. The third portion 506 is coupled to the outer shaft 300 using, a technique such as, without limitation, press-fitting, adhesive bonding, threaded coupling, interference fit, etc. In an example implementation, the third portion 506 is coupled to the outer shaft 300 using press-fitting. In one embodiment, the third portion 506 may have a smaller outer-circumference than the stem lumen 302a of the stem 302 of the outer shaft 300 and thus, the third portion 506 is inserted into the stem lumen 302a of the stem 302. In another embodiment, a lumen of the third portion 506 may have a larger circumference than an outer-circumference of the stem 302 and thus, the stem 302 is inserted into the lumen of the third portion 506. The third portion 506 may have a shape, such as, without limitation, cube, cuboidal, cylindrical, etc. In an embodiment, the third portion 506 has a solid cylindrical structure. The control element 500 may be made of a material including, without limitation, polycarbonate, acrylonitrile butadiene Styrene (ABS), polyetheretherketone, polyethylene, etc. In an example implementation, the control element 500 is made of ABS.
[0058] The depicted embodiment includes an outer shaft and an inner shaft, wherein the outer shaft is movable in response to the actuation provided by the control element of the handle and the inner shaft remains stationary. However, in an alternate embodiment, the inner shaft may be movable with respect to the actuation provided by the control element and the outer shaft may remain stationary. For example, the control element 500 may be coupled to the inner shaft 400 to facilitate an axial movement of the inner shaft 400, resulting in the radial movement of the curved struts 114 of the retrieval assembly 100. The control element 450 is configured to move the inner shaft 400 axially and is configured to expand and collapse the retrieval assembly 100.
[0059] The control element 500 is configured to be in one of an actuated state and an unactuated state. In response to the control element 500 in the actuated state input, the outer shaft 300 is configured to move axially in the proximal (or backward) direction towards the proximal end 200a of the deployment system 200. The proximal movement of the outer shaft 300 causes the inner shaft 400, along with the retrieval assembly 100 to advance and gradually exit the outer shaft 300. In other words, in an actuated state, the outer shaft 300 is configured to expose the retrieval assembly 100 from the inner shaft 400. As the retrieval assembly 100 is exposed, the constraining force applied by the outer shaft 300 is reduced, allowing the curved struts 114 of the basket 110 of the retrieval assembly 100 to radially expand. Consequently, the braided element 120 in the braided element 120 of the retrieval assembly 100 also expands, resulting in it adopting an expanded state.
[0060] In response to the control element 500 at the unactuated state, the outer shaft 300 is configured to move axially in a distal (or forward direction) towards the distal end 200b of the deployment system 200. In other words, in an unactuated state, the outer shaft 300 is configured to cover the inner shaft 400 and the retrieval assembly 100 completely. As the inner shaft 400 gradually moves into the outer shaft 300, the retrieval assembly 100 collapses radially due to the constraining force applied by the outer shaft 300, resulting in a collapsed state. According to an embodiment, the actuated state and the unactuated state correspond to sliding (or moving) the control element 500. In another embodiment, the control element 500 may be a roller (not shown). In this case, the first and unactuated states may correspond to rotating the control element 500 in a first and a second direction, respectively. The control element 500 may be coupled to the outer shaft 300 such that rotating the control element 500 in the first direction causes the outer shaft 300 to axially move in the proximal direction and rotating the control element 500 in the second direction causes the outer shaft 300 to axially move in the distal direction. The first direction may be clockwise and the second direction may be anticlockwise, or vice versa.
[0061] The handle 600 is disposed at the proximal end 200a of the deployment system 100. Fig. 10 depicts a perspective view of the handle 600 of the deployment system 200, in accordance with an embodiment of the present invention. The handle 600 is used for holding and maneuvering the deployment system 200 to expand and collapse the retrieval assembly 100 of the present disclosure. The handle 600 has a proximal end 600a and a distal end 600b. The handle 600 is ergonomically designed to provide an optimized grip of the deployment system 200. In an embodiment, handle 600 has an elongated, generally cuboidal shape. The handle 600 may be made of a material including, but not limited to, polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyetheretherketone (PEEK), polyethylene (PE), etc. In an example implementation, the handle 600 is made of ABS.
[0062] The handle 600 is at least partially hollow and includes a cavity 600c. The cavity 600c of the handle 600 receives a proximal portion of the outer shaft 300. At least the partial length of the proximal end 300a of the outer shaft 300 is disposed within the handle 600. The handle 600 includes a hole 600d at the distal end 600b. In an embodiment, the hole 600d extends into the cavity 600c. The hole 600d receives the outer shaft 300 and the inner shaft 400. The dimensions of the hole 600d are designed to allow longitudinal or axial movement of the outer shaft 300. The handle 600 includes a longitudinal slot 602 to receive the control element 500, for example, the second portion 504 of the control element 500 is disposed in the longitudinal slot 602. The longitudinal slot 602 extends into the cavity 600c of the handle 600 and extends longitudinally for at least a partial length of the handle 600. The cavity 600c receives the third portion 506 of the control element 500. The longitudinal slot 602 has a proximal end 602a and a distal end 602b. The control element 500 is movable within the longitudinal slot 602 between the proximal end 602a and the distal end 602b, wherein in response to the movement of the control element 500 towards the proximal end 602a of the slot 602, the outer shaft 300 is configured to move axially in a proximal direction. Similarly, in response to the movement of the control element 500 towards the distal end 602b, the outer shaft 300 is configured to move axially in the distal direction. The cross-sectional shape and dimensions of the longitudinal slot 602 correspond to the cross-sectional shape and dimensions of the second portion 504 of the control element 500.
[0063] The position of the control element 500 within the longitudinal slot 602 is adjusted to control the state of the retrieval assembly 100. When the control element 500 is at the distal end 602b of the longitudinal slot 602, the inner shaft 400 and the retrieval assembly 100 reside within the outer shaft 300, and the curved struts 114 of the retrieval assembly 100 are flexed radially inward to be in the collapsed state. Thus, in the collapsed state, the control element 500 is at the distal end 602b of the longitudinal slot 602. The length of the longitudinal slot 602 may be designed such that when the control element 500 is at proximal end 600a the retrieval assembly 100 is completely disposed outside the outer shaft 300 to be in the expanded state. Thus, in the expanded state, the control element 500 is at the proximal end 602a of the longitudinal slot 602.
[0064] While the depicted embodiment includes a control element which is a sliding button being disposed in a corresponding longitudinal slot of a handle, a person skilled in the art will appreciate that other suitable controlling mechanisms may be used while practicing the inventive features of the present disclosure and the same are within the scope of the present disclosure.
[0065] An embodiment of coupling between various components of the deployment system 200 is now explained. The retrieval assembly 100 is removably coupled to the inner shaft 400 via the jacket 130. The protrusion 402 of the inner shaft 400 has a plurality of threads configured to mate with the inner threads 134a of the jacket lumen 134 in the jacket 130, ensuring a secure and removable attachment. The inner shaft 400 is disposed within the outer lumen 300c of the outer shaft 300. The outer shaft 300 is coupled to the control element 500, which is disposed within the longitudinal slot 602 of the handle 600. The control element 500 includes a third portion 506, which is inserted into the stem lumen 302a of the stem 302 of the outer shaft 300. The handle 600 houses the proximal end 300a of the outer shaft 300 and the inner shaft 400. The distal end 600b of the handle 600 includes a hole 600d, allowing passage of the outer shaft 300 and inner shaft 400. The longitudinal slot 602 of the handle 600 guides the movement of the control element 500, which in turn controls the axial displacement of the inner shaft 400 and the expansion or collapse of the retrieval assembly 100.
[0066] An exemplary working of the deployment system 200 and retrieval assembly 100 is now explained. To set the retrieval assembly 100 in the radially expanded state, the control element 500 is moved within the longitudinal slot 602 towards the proximal end 602a of the slot 602. This movement causes the outer shaft 300 to move axially in the proximal direction. As the outer shaft 300 moves proximally, the retrieval assembly 100 and the inner shaft 400 begin to exit the outer shaft 300. As a result, the constraining force applied by the outer shaft 300 is reduced, allowing the curved struts 114 of the basket 110 of the retrieval assembly 100 to flex radially outward. The braided element 120 of the braided element 120 also expands, ensuring the retrieval assembly 100 fully opens to capture the stone. When the control element 500 is positioned at the proximal end 602a of the slot 602, the retrieval assembly 100 expands to the fullest. At this stage, the basket 110 of the retrieval assembly 100 achieves its maximum expansion, the curved struts 114 return to their pre-defined convex shape, and the cover 10, positioned at the distal end 100b, forms a pocket that facilitates stone capture.
[0067] Similarly, to set the retrieval assembly 100 in the radially collapsed state, the control element 500 is moved within the longitudinal slot 602 towards the distal end 602b of the slot 602. This movement causes the outer shaft 300 to move axially in the distal direction. As the outer shaft 300 moves distally, the retrieval assembly 100 and the inner shaft 400 gradually retract into the outer shaft 300. As a result, the constraining force applied by the outer shaft 300 increases, causing the curved struts 114 to flex radially inward. The braided element 120 also contracts as the retrieval assembly 100 collapses to its minimal profile. When the control element 500 is positioned at the distal end 602b of the slot 602, the retrieval assembly 100 collapses to the fullest, and the curved struts 114 are in their fully compressed state. The radial expansion and collapse of the retrieval assembly 100 are precisely controlled by the axial movement of the inner shaft 400, ensuring efficient stone retrieval while maintaining a minimally invasive approach.
[0068] Fig. 11 depicts a flowchart of a method 700 for using the deployment system 200 and the retrieval assembly 100 for stone retrieval, according to an embodiment of the present disclosure.
[0069] At step 701, the distal end 200b of the deployment system 200 is inserted into the patient’s body and navigated towards the target site, as depicted in Figs. 12A. The navigation is performed using imaging guidance techniques to ensure accurate positioning of the retrieval assembly 100 at the target site, as shown in Figs. 12B.
[0070] At step 703, the control element 500 is pushed in the backward direction towards the proximal end 600a of the handle 600, as shown in Fig. 12B. This movement causes the retrieval assembly 100 to expand radially, allowing it to open fully at the target site.
[0071] At step 705, a stone 20 is captured within the retrieval assembly 100, as illustrated in Fig. 12C. The expanded curved struts 114 and braided element 120 of the retrieval assembly 100 facilitate secure entrapment of the stone 20 while minimizing trauma to surrounding tissues.
[0072] At step 707, the control element 500 is pushed in the forward direction towards the distal end 600b of the handle 600. This causes the retrieval assembly 100 to collapse radially, securely enclosing the captured stone 20 within the retrieval assembly 100 and the outer shaft 300.
[0073] At step 709, the deployment system 200 is withdrawn from the patient’s body once the stone 20 has been securely captured within the retrieval assembly 100. The collapsed profile of the retrieval assembly 100 ensures a smooth and minimally invasive retrieval process.
[0074] The proposed retrieval assembly and deployment system present several advantages over conventional stone retrieval devices. The retrieval assembly features a braided element and struts that allow for controlled radial expansion and collapse, ensuring secure stone capture while minimizing trauma to surrounding tissues. The expandable design enhances the effectiveness of stone retrieval by conforming to the shape of the stone and reducing the risk of slippage during extraction. The deployment system provides precise control over the retrieval assembly through the control element and the handle. This controlled movement enables smooth deployment and retraction of the retrieval assembly, reducing procedural complexity and improving ease of use. The jacket with a threaded lumen facilitates a secure yet removable coupling between the retrieval assembly and the delivery system, allowing for efficient device assembly and disassembly.
[0075] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used.
, C , C , Claims:WE CLAIM
1. A retrieval assembly (100) comprising:
a. a basket (110) including:
i. a central element (112) provided at a distal end (100b) of the retrieval assembly (100);
ii. a plurality of curved struts (114) extending from the central element (112), each curved strut having a distal end and a proximal end, each curved strut (114) including a ring (114a) at the proximal end; and
iii. a cover (10) surrounding an outer surface of the plurality of curved struts (114); and
b. a plurality of braided elements (120) with each braided element (120) coupled to the ring (114a) of a respective curved strut (114);
wherein the proximal ends of the plurality of curved struts (114) are configured to move outwards once unsheathed, causing the basket (110) to expand; and
wherein, the braided elements (120) are configured to restrict the expansion of the curved struts (114).
2. The retrieval assembly (100) as claimed in claim 1, wherein each braided element (120) includes a plurality of filaments (122) braided to form a lattice-like structure.
3. The retrieval assembly (100) as claimed in claim 1, wherein the braided elements (120) pass through respective rings (114a) of the curved struts (114).
4. The retrieval assembly (100) as claimed in claim 1, wherein the basket (110) is constructed using a laser-cut technique.
5. The retrieval assembly (100) as claimed in claim 1, wherein the basket (110) is configured to expand to form a predefined shape including one of a U-shape, a C-shape, a convex shape, a concave shape, or a sinusoidal shape.
6. The retrieval assembly (100) as claimed in claim 1, wherein each curved strut (114) includes a curvature at an angle of curvature (θ) ranging between 30° and 120°.
7. The retrieval assembly (100) as claimed in claim 1, wherein each curved strut (114) includes a radius of curvature (R) ranging between 3 mm and 5 mm.
8. The retrieval assembly (100) as claimed in claim 1, wherein two adjacent curved struts 114 (S) include a spacing ranging from 4 mm to 10 mm.
9. The retrieval assembly (100) as claimed in claim 1, wherein the retrieval assembly (100) includes a jacket (130) positioned at a proximal end (100a) of the retrieval assembly (100), the jacket (130) includes:
a. a cavity (132) housing free ends of the braided elements (120); and
b. a jacket lumen (134) coupled to a deployment system (200).
10. A deployment system (200) for deploying a retrieval assembly (100), the deployment system (200) comprising:
a. an outer shaft (300);
b. an inner shaft (400) at least partially disposed within the outer shaft (300) and removably coupled to a jacket (130) of the retrieval assembly (100); and
c. a control element (500) coupled to one of the outer shaft (300) or the inner shaft (400), the control element (500) configured to be in one of an actuated state or an unactuated state;
wherein, in the unactuated state, the outer shaft (300) is configured to cover the inner shaft (400) and the retrieval assembly (100) completely;
wherein, in the actuated state, the outer shaft (300) is configured to expose the retrieval assembly (100) from the inner shaft (400).
11. The deployment system (200) as claimed in claim 10, wherein the outer shaft (300) includes a stem (302) towards a proximal end (300a) to couple to the control element (500).
12. The deployment system (200) as claimed in claim 10, wherein the inner shaft (400) includes a protrusion (402) with a plurality of outer threads, the jacket (130) includes a plurality of inner threads (134a), the inner threads (134a) of the jacket (130) couple to the outer threads of the inner shaft (400).
13. The deployment system (200) as claimed in claim 10, wherein the deployment system (200) includes a handle (600) having a longitudinal slot (602).
14. The deployment system (200) as claimed in claim 13, wherein the control element (500) is disposed in the longitudinal slot (602) and is movable between a proximal end (602a) and a distal end (602b) of the longitudinal slot (602), wherein in response to movement of the control element (500) in the slot (602), one of the inner shaft or the outer shaft (300) is configured to move axially in a corresponding direction as that of the control element (500).