Surgical devices

Abstract

The disclosed surgical device (1) is for securing a nonwoven fabric to human or animal soft tissue by releasing a portion of the nonwoven fabric's individual fibers and transporting them into the soft tissue. The device includes a carrier (4) extending in a longitudinal direction (x), the carrier including a guide rod (5) and a felting needle (6) attached to the distal end of the guide rod. The guide rod (5) has a rearward end (13) coupled to a drive mechanism (14) via a force-limiting element (15) that, upon actuation, limits the force applied by the drive mechanism (14) to a predetermined force threshold when the actuating tip (7) moves from a retracted position to an extended position.

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to a surgical device for attaching nonwoven fabrics to human or animal soft tissue. [Background technology]

[0002] Nonwoven embedded fabrics, particularly felts, are used in a variety of applications, including general surgery, joint capsule surgery, and cardiac surgery. Traditionally, felts have been connected to tissue using traditional suturing techniques. The drawbacks of using suturing to achieve a connection are that the quality of the connection between the felt and the tissue is limited by the number of sutures used, and when the felt is subjected to high forces, the threads can tear through the tissue, creating so-called "cheese wires," causing tissue damage.

[0003] A surgical device was developed in which felting needles are repeatedly driven through the felt into the tissue, thereby depositing some of the fibers of the felt material into the tissue. By moving the needles across the felt material, a strong, well-distributed connection is formed between the felt and the tissue.

[0004] WO2022 / 100833A1 discloses a surgical device having a felt needle configured for reciprocating motion. The surgical device includes a guide tube and a moving rod disposed within the guide connected to the needle. A needle protection mechanism is disclosed that protects the needle from damage during reciprocating motion due to contact with a rigid structure. The needle protection mechanism is disposed between the moving rod and the needle. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present disclosure to provide a surgical device, and in particular a surgical device for attaching nonwoven fabrics to human or animal soft tissue, that does not suffer from at least some of the drawbacks of the prior art. [Means for solving the problem]

[0006] A surgical device is disclosed. The surgical device is suitable for attaching a nonwoven fabric to human or animal soft tissue by removing a portion of the nonwoven fabric's individual fibers and delivering them to the human or animal soft tissue. The portion of the individual fibers can be pushed, pulled, or otherwise brought to or deposited on the human or animal soft tissue, thereby attaching, connecting, or securing the nonwoven fabric fibers to the soft tissue. The surgical device includes a longitudinally extending carrier, which includes a guide rod and a felting needle, the felting needle attached to the distal end of the guide rod. The felting needle is an elongated member including a working tip at its distal end, which preferably includes, for example, a sharp tip, a blade, a blunt tip, or a flat end, or a combination thereof. The guide rod and felting needle are at least partially disposed within the guide bushing and are reciprocally movable between an extended position in which the working tip of the felting needle protrudes beyond an opening disposed at the distal end of the guide bushing and a retracted position in which the working tip of the felting needle does not protrude beyond the opening disposed at the distal end of the guide bushing. The guide rod is distally coupled to the drive mechanism via a force limiting element. The force control element is distally coupled to the drive mechanism via the force limiting element, which during actuation limits the force applied to the guide rod by the drive mechanism to a predetermined force threshold when the working tip is moved from the retracted position to the extended position.

[0007] In one embodiment, the force-limiting element is further configured not to limit the force applied by the drive mechanism to the guide rod when the actuating tip moves from the extended position to the retracted position to a predetermined force threshold. Thus, the force transfer during retraction of the actuating tip is not limited to the predetermined force threshold. In particular, the drive mechanism may apply a force greater than the predetermined force threshold to the guide rod as the actuating tip is retracted. This is beneficial for returning the actuating tip to the retracted position in situations where the actuating tip may trip or become partially jammed, particularly in situations where the force-limiting element may become engaged during movement of the actuating tip from the extended position to the retracted position.

[0008] In one embodiment, the force-limiting element is configured to have a predetermined retraction force threshold that, during actuation, limits the force applied by the drive mechanism to the guide rod when the actuation tip moves from the extended position to the extended position. The predetermined retraction force threshold can be different from the predetermined force threshold during extension, and in particular, the predetermined retraction force threshold can be greater than or less than the predetermined force threshold during extension.

[0009] In one embodiment, the force-limiting element comprises a deformable element that deforms when a predetermined force threshold is reached in the longitudinal direction, thereby interrupting force transmission in the longitudinal direction. Preferably, the force-limiting element does not attenuate the force applied by the drive mechanism until the predetermined force threshold is reached. Preferably, the force-limiting element is configured to return to its initial state when the applied force is removed and / or when the felting needles are returned to their retracted position. Preferably, the force-limiting member does not break when the predetermined force threshold is exceeded.

[0010] For example, the deformable element may be a buckling element extending between first and second longitudinal ends, the buckling element being configured to deform in a lateral direction perpendicular to the longitudinal direction upon reaching a predetermined force threshold, the buckling element being configured to buckle upon reaching the predetermined force threshold, and the buckling element may have a round, rectangular, oval, and / or V-shaped cross section.

[0011] The force-limiting mechanism may exhibit hysteresis. For example, in situations where the force applied to the working tip in the longitudinal direction (particularly at a particular force directed toward the dorsal end of the working tip) exceeds a predetermined force threshold, the force-limiting mechanism may exhibit hysteresis in the longitudinal displacement of the working tip of the felting needle as a function of displacement of the drive mechanism in the longitudinal direction. In particular, the displacement of the working tip of the felting needle from a retracted position to an extended position as a function of displacement of the drive mechanism may be different from the displacement from the extended position to the retracted position. Additionally or alternatively, in situations where the force applied to the working tip in the longitudinal direction (particularly at a particular force directed toward the dorsal end of the working tip) exceeds a predetermined force threshold, the force applied to the working tip of the needle in the longitudinal direction as a function of displacement of the drive mechanism may exhibit hysteresis. Specifically, when the needle strikes a hard object during extension, the force applied to the needle by the drive mechanism rapidly increases until a predetermined force threshold is met, after which the force remains constant or decreases (preferably interrupted at the point where the force suddenly decreases). For example, the drive mechanism may become substantially disengaged from the actuating tip. However, in the opposite direction, particularly when the actuating tip moves from the extended position toward the retracted position, the force-limiting mechanism may not limit the pulling force exerted on the actuating tip by the drive mechanism to the predetermined force threshold. As a result, if the actuating tip becomes stuck in a hard object (such as hard tissue) and the force threshold is reached, the actuating tip can be pulled out of the hard object with greater force, ensuring that the actuating tip can still be removed even if the delivery means engages the hard object. The buckling element can be clamped at the first end and / or the second end. In particular, the buckling element can be fixed to the guide rod at its first (distal) end and / or fixed to the drive element at its second (rear) end. Alternatively, the buckling element may be povitably attached to the first end and / or the second end.

[0012] In one embodiment, the buckling element may be pre-formed so that the buckling element buckles when a predetermined force threshold is reached during operation. Pre-forming may include stressing the buckling element, annealing the buckling element, and / or bending the buckling element. Pre-forming may include introducing imperfections such as dents, defects, stress risers, etc.

[0013] In one embodiment, the working tip of the felting needle comprises a delivery means for supporting the delivery of some of the individual fibers of the nonwoven fabric to the soft tissue.

[0014] In one embodiment, the conveying means includes an essentially flat end disposed at the distal end of the working tip. The essentially or substantially flat end can include one or more flat and / or curved surfaces disposed substantially perpendicular to the longitudinal direction. The flat end section can have, for example, a round, oval, and / or rectangular cross section. The flat end can include protrusions and / or recesses designed to capture, hook, and / or pull fibers. The flat end can have surface roughness.

[0015] Additionally or alternatively, the delivery means of the working tip may include protrusions and / or recesses along the outer shaft of the working tip for delivering individual fiber portions into the soft tissue. The protrusions and / or recesses may be designed as depressions or recesses into the outer shaft and / or as protrusions from the outer shaft. The protrusions and / or recesses may include, for example, hook elements, crowns, notches, and / or barbs. The working tip may have a circular cross-section, a triangular cross-section, a star-shaped cross-section, a helical cross-section, and / or a threaded cross-section.

[0016] In one embodiment, the surgical device comprises a frame to which the guide bushing and drive mechanism are mounted.

[0017] The frame may include a recess in which the force-limiting element is disposed between the rear end of the guide bushing and the drive mechanism. The recess may be specifically designed to accommodate buckling of a buckling element having a lateral dimension greater than the extent of the buckling element.

[0018] In one embodiment, the channel extends longitudinally between the guide rod and the guide bushing. The channel prevents the buildup of a longitudinal pressure differential, thereby preventing a pumping effect in which reciprocating motion would pump fluid, e.g., air, distally. Preferably, the channel extends half the distance between the guide rod and the guide bushing.

[0019] For example, the guide rod may include or define a longitudinally extending channel. Additionally or alternatively, the guide bushing may comprise or define the channel.

[0020] The drive mechanism may include an adapter that connects the drive mechanism to an external actuator. The external actuator is configured to engage with the adapter to drive the drive mechanism via the adapter. The external actuator may be releasably connected to the surgical device using, for example, a releasable snap-fit ​​mechanism. The external actuator may be powered by electrical energy, pneumatic energy, etc.

[0021] In one embodiment, the opening of the guide bushing is formed by a guide bushing collar having an inner diameter smaller than the inner diameter of the guide bushing. The guide bushing collar includes a transitional surface at its distal end and / or rear end. The transitional surface is designed to allow the felting needle to properly extend and retract in and out of the guide bushing collar, and in particular to prevent the working tip of the felting needle from snagging or catching on the guide bushing collar when a lateral force is applied to the felting needle during extension and retraction. The transitional surface may include one or more bevels, chamfers, and / or roundings. Essentially, the transitional surface is oriented such that the felting needle is deflected toward and away from the longitudinal direction when it strikes the transitional surface.

[0022] In a preferred variation, the felting needle is made of metal, e.g., stainless steel or a metal alloy such as Nitinol. The guide rod is made, for example, of an injection-molded plastic material that at least partially encompasses the felting needle opposite the working tip, thereby securely attaching the felting needle to the guide rod. The frame can be made of an injection-molded fiber-reinforced plastic material.

[0023] In one embodiment, the force-limiting element and the felting needles are integrally formed and extend through the guide rod.

[0024] In one embodiment, the guide rod includes at least two opposing recesses between which a portion of the force-limiting member is disposed.

[0025] In a variant, the force-limiting element is coupled to the drive mechanism by a piston rod. The drive mechanism may also include a piston rod. The piston rod may be connected to a slide pin attached to a rotating element driven by an external actuator.

[0026] In a variant, the force-limiting element is coupled to the drive mechanism by a Scotch yoke, which comprises a slide yoke and a connecting rod attached to the force-limiting element, and which further includes a slide pin attached to a rotating element driven by an external actuator.

[0027] The rotating element may be, for example, a crank, a wheel, or a disk.

[0028] The frame can include a longitudinally disposed cylinder. The drive mechanism can include a piston (or connecting rod) disposed at least partially within the cylinder. The piston is connected at a distal end of the force-limiting element and a rearward end of the piston rod. The cylinder is configured to guide the piston or connecting rod through a reciprocating motion during operation of the surgical device.

[0029] The frame may be at least partially enclosed by an outer housing, which may include two housing halves made from an injection molded plastic material.

[0030] The guide rod may include at least two longitudinally spaced apart guide surfaces, which are preferably designed to provide a low friction interface between the guide rod and the guide bushing.

[0031] It should be understood that both the foregoing general description and the following detailed description are intended to present embodiments of the disclosure and to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the disclosed concepts. [Brief explanation of the drawings]

[0032] The invention described herein will be more fully understood from the following detailed description and the accompanying drawings, which are not to be construed as limiting the invention as claimed. [Figure 1] 1 is a schematic side view of a surgical device. [Figure 2] 1 is a schematic exploded perspective view of a surgical device. [Figure 3] FIG. 2 is a schematic perspective view of a carrier. [Figure 4] 1 shows a partial perspective view of the carrier including the distal end of the guide rod and the felting needle. [Figure 5] 1 shows a schematic perspective view of the working tip of a felting needle. [Figure 6] 10 is a schematic perspective view including an inner line of a cross section of a carrier including the rear end of a guide rod and a portion of a force-limiting element; [Figure 7] FIG. [Figure 8] 1 shows a schematic cutaway perspective view of the distal end of the guide bushing, and further shows the distal end of the carrier including a portion of the guide rod and the felting needle in the retracted position. [Figure 9] 1 shows a schematic cutaway perspective view of a portion of a surgical device including, in particular, a force-limiting element and a drive mechanism. [Figure 10] Schematically show three top views of the surgical device with the felting needles in a retracted position, an extended position, and with the felting needles partially extended and in contact with a surface such that a force-limiting element is involved. [Figure 11] Shown are two charts showing needle displacement and force applied to the needle tip as a function of drive mechanism displacement. DETAILED DESCRIPTION OF THE INVENTION

[0033] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings. Some, but not all, features are shown in the drawings. Indeed, the embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Wherever possible, reference numerals will be used to refer to like components or parts.

[0034] FIG. 1 shows a side view of a schematic diagram of a surgical device 1. The surgical device 1 is a handheld device typically used by a surgeon during surgery. The surgical device 1 is used to connect nonwoven fabrics, such as felt, to soft tissue within the human or animal body. The surgical device 1 is a sterilized device and is typically manufactured and assembled in a clean room environment. The surgical instrument 1 is typically sterilized after assembly and stored in a sterile package for use in surgery. After use, the surgical instrument 1 must be cleaned and sterilized or discarded.

[0035] For sterilization purposes, e.g., during or after manufacture or after use, it is important that the distal end of surgical device 1, and particularly any parts that enter or come into contact with a human or animal, be easily accessible by a sterilizing fluid. In particular, sterilizing fluid must be able to circulate freely over all exterior and interior surfaces of surgical device 1.

[0036] The surgical device 1 has an outer housing 28 made of a plastic material formed by injection molding. The outer housing 28 defines a grip area where a surgeon can hold the surgical device 1. The outer housing 28 further defines a longitudinally elongated upper portion, which includes an opening designed to receive the guide bushing 28. The outer housing 28 is formed from two parts that are attached to each other along a joint line. The joint line extends substantially around the outer housing 28 in the lateral (yz) plane. This reduces the risk of pinching a surgical glove in the joint line during surgery. The two parts are joined using a press-fit connection, adhesive, and / or additional retention mechanisms, including, for example, a snap-fit ​​mechanism, screws, or the like.

[0037] The guide bushing 8 is attached to the outer housing 28, particularly to an opening in the outer housing 28, at its rear end 28. The guide bushing 8 has an elongated shape, for example, a hollow cylindrical shape, for example, a hollow circular cylindrical shape, with a diameter of 2 mm to 10 mm, preferably 3 mm to 8 mm, and more preferably 5 mm. The guide bushing 8 has a longitudinal extension of 2 cm to 30 cm, preferably 5 cm to 20 cm, and more preferably 15 cm. The guide bushing 8 has a distal end 19 including an opening 11. The distal end 19 may be beveled, chamfered, and / or filleted. The guide bushing 28 at its rear end opens into the interior of the outer housing 28.

[0038] The guide bushing 8 at least partially encloses a carrier 4 (not shown), which carries a guide rod 5 and felting needles 6. The guide rod 5 has a cross-sectional shape that is at least partially complementary to the internal cross-section of the guide rod 5, allowing the guide rod 5 to reciprocate longitudinally (i.e., move back and forth) within the guide bushing 8 without excessive lateral movement. The carrier 4 is described in more detail below with reference to Figures 2-4.

[0039] In one embodiment, the guide bushing 8 can be flexible over at least a portion of its length. The guide bushing 8 can be implemented as a catheter. The guide bushing 8 can be flexible over its entire length. The guide bushing 8 can be bent into a specific shape and retain that shape after bending. Thus, the guide bushing 8 can be formed into a specific shape for a specific procedure, for example, to optimally reach a surgical site. Flexibility as described herein can be understood in that the guide bushing 8 can be bent and / or brought into a bent shape, particularly while navigating a tortuous path in a hollow organ (e.g., a blood vessel). Preferably, the guide bushing 8 is flexible over its entire length. Alternatively, the guide bushing 8 can have one or more flexible sections.

[0040] In the extended position, the working tips 7 of the felting needles 6 are shown extending out of (i.e., beyond) the openings 11. In the retracted position, the working tips 7 of the felting needles 6 are retracted inside the openings 11.

[0041] The external actuator 25 is releasably connected to the surgical device 1 and drives a drive mechanism (not shown). The external actuator 25 may be connected using a snap-fit ​​connector, such as a cantilever snap-fit ​​connector. A portion of the cantilever arm extends through the outer housing 28, which, when depressed, disengages the snap-fit ​​connection and releases the external actuator 25. When the external actuator 25 is turned on, the working tip 7 of the felting needle 6 moves back and forth in a reciprocating motion between a retracted position and an extended position. Preferably, the frequency of the reciprocating motion is between 1 and 200 Hz, preferably 10 and 100 Hz, most preferably 20 and 80 Hz, and in certain instances, 40 Hz. When the external actuator 25 is turned off, the working tip 7 returns to the retracted position, as described in more detail below with reference to FIG. 2.

[0042] FIG. 2 shows the interior of the surgical device 1. A frame 21 is disposed inside the outer housing 28. The frame 21 has an opening at its distal end in the longitudinal direction x for receiving the rear end of the carrier 4, particularly the guide rod 5. The frame 21 has a recess 22 adjacent to the opening, in which the force-limiting element 16 is disposed. The recess 22 is designed to have sufficient space for the force-limiting element 16, particularly the buckling element 16, to buckle in the lateral directions x and y. The buckling element 16 is preferably configured to buckle in the lateral directions x and y when a predefined force threshold is met. The force-limiting element 16 is connected to the carrier 4, particularly the guide rod 5. For example, the force-limiting element 16 is fixed to the rear end of the guide rod 5.

[0043] The force-limiting element 16 is connected at its rear end 17 to the drive mechanism 14. The drive mechanism 14 is connected to an external actuator 25 in operation. The drive mechanism 14 may include an adapter 24 configured to engage a rotating end of the external actuator 25. The drive mechanism 14, particularly the adapter 24, is configured to convert the rotational motion of the external actuator into reciprocating motion for driving the carrier 4 in a reciprocating motion. The drive mechanism 14 may include a piston rod, a scotch yoke 27, or another suitable mechanism for converting rotational motion. Specifically, the external actuator 25 is configured to rotate in the x-y plane. The adapter 24 engages with the external actuator 25.

[0044] The adapter 24 may include a slide pin that rotates within a horizontal x-y plane. The slide pin may be disposed, for example, on a crank, wheel, or disk of the adapter 24. Specifically, the slide pin revolves around a rotation axis extending in the z-direction within the horizontal x-y plane.

[0045] In one embodiment, the force-limiting element 16 is directly connected to the sliding pin. For example, the force-limiting element 16 may comprise a ring portion mounted on the sliding pin such that the force-limiting element 16 is directly driven by the circular motion of the sliding pin, thereby also acting as a piston rod.

[0046] Alternatively, the slide pin engages with the piston rod or the yoke of a Scotch yoke connector.

[0047] The adapter 24 is configured so that the rotation diameter of the slide pin is between 5 and 40 mm, preferably between 10 and 30 mm, and most preferably between 15 and 20 mm. The rotation diameter defines the range of motion of the carrier 4. Specifically, the rotation diameter defines the range of motion of the needle's working tip 7 between the retracted and extended positions. The maximum extension of the needle's working tip 7 beyond the opening 11 is defined by the rotation diameter and the distance between the opening 11 and the working tip 7 when the working tip 7 is in the retracted position. Preferably, the surgical device 1, particularly the rotation diameter and the distance between the opening 11 and the retracted working tip 7, are designed so that the maximum extension of the working tip 7 is between 1 and 30 mm, preferably between 6 and 15 mm. Specific examples of maximum extension are 6.5 mm, 8.5 mm, or 12 mm.

[0048] The working tip 7 includes a conveying means configured to convey (e.g., transport by pushing, pulling, or dragging) a portion, i.e., length, of the fibers of the nonwoven fabric into the soft tissue as the working tip 7 moves through the nonwoven fabric and into the soft tissue.

[0049] A delivery means may be disposed at the distal end of the working tip 7, which delivery means advantageously enables the working tip 7 to deposit a length of fiber to a maximum penetration depth of the working tip 7. A delivery means disposed at the distal end of the working tip 7 may include, for example, a flat end 41 of the working tip 7.

[0050] Additionally or alternatively, the delivery means may be located on the outer shaft 40 of the working tip.

[0051] The drive mechanism 24 includes a biasing member 31, such as a coil spring, configured to return the carrier 4 to the retracted position when the external actuator 25 is turned off. Specifically, the biasing force of the biasing member 31 is configured to exceed the breakaway force of the external actuator 25. The biasing member 31 has one end connected to the frame 21, particularly to a lateral interior wall of the frame 21, and the other end connected to the adapter 24. The lateral interior wall is disposed in the yz plane and divides the frame 21 into a distal portion that substantially surrounds the force-limiting element 16 and a rear portion in which the drive mechanism 14 is substantially disposed. The biasing member may be disposed around the rear end of the force-limiting element 16 to achieve a compact design.

[0052] Frame 21 further includes bearings 32 oriented in longitudinal direction x, which are configured to longitudinally limit the movement of drive mechanism 14 and / or force-limiting element 16. More specifically, pistons or connecting rods of drive mechanism 14 and / or force-limiting element 16 are disposed within bearings 32. Bearings 32 are preferably disposed adjacent to an interior wall of frame 21.

[0053] FIG. 3 shows a schematic perspective view of the carrier 4. The carrier 4 comprises felting needles 6 and guide rods 5. The felting needles 6 are arranged at the distal end of the carrier 4 (in the positive longitudinal direction x) and are connected to the guide rods 5. The carrier 4 is connected at its rear end to a force-limiting element 16. The guide rods 5 have a cylindrical shape, e.g., a circular, oval, or rectangular cylindrical shape, with a cross-sectional extension (e.g., diameter) of 2 mm to 8 mm, preferably 5 mm. The guide rods 5 are preferably made of an injection-molded plastic material. The guide rods 5 may have edge fillets.

[0054] The carrier 4 is manufactured, for example, by placing the rear portions of the felting needles 6 and the distal portions of the force-limiting elements 16 in a mould and then injecting plastic material to form the guide rods 5 .

[0055] In one embodiment, the felting needles 6 and the force limiting element 16 are integrally formed, i.e., consist of one continuous part, and the guide rod 5 is formed by injection molding a plastic material around the felting needles 6 and the force limiting element 16.

[0056] The guide rod 5 can include one or more channels 23 on its outer surface, the channels 23 extending along at least a portion of the outer surface of the guide rod 5. The channels 23 serve to prevent a buildup of pressure inside the guide bushing 8 due to the reciprocating motion of the carrier 4 when the surgical device 1 is in operation.

[0057] The channel 23 can further engage with a guide means on the inner surface of the guide bushing 8, which has a shape complementary to the guide bushing 8 and serves to guide the guide rod 5 within the guide bushing 8 in a predetermined direction (i.e., at a predetermined angle in the yz plane). In other words, the channel 23 can mesh with the guide means to prevent the guide rod 8 from rotating about the directional axis x.

[0058] The guide rod 5 may further include one or more guide surfaces 30 configured to slidably engage the guide bushing 8. The guide surfaces 30 may be formed from a different material than the rest of the guide rod 5. For example, the guide surfaces 30 may be formed from a material that reduces friction between the guide rod 5 and the guide bushing 8, such as PTFE. The guide surfaces 30 may have a lateral cross-section that is at least partially complementary to the lateral internal cross-section of the guide bushing 8. The guide surfaces 30 have a defined longitudinal extension, for example, a longitudinal extension of about 10 mm. The guide surfaces 30 are preferably located at or near the distal end of the guide rod 5 and at or near the rearward end of the guide rod 5, i.e., rearward and / or within 3 cm of the distal end of the guide rod.

[0059] The guide surface 30 preferably does not surround the entire section of the guide rod 8, and preferably has at least one gap to allow air to move past the guide surface 30 and prevent any pressure buildup.

[0060] In one embodiment, the guide rod 5 is flexible over at least a portion of its length. The guide rod 5 may be flexible over its entire length. Alternatively, the guide rod 5 may be flexible only over a specific portion. The guide rod 5 may be implemented as a flexible drive element configured to transmit a drive force from the drive mechanism 14 to the felting needles 6. The flexible drive element may be implemented, for example, as a drive wire connected to the distal end of the felting needles 6 and the proximal end of the force-limiting element 16. Optionally, a guide element may be longitudinally disposed along the drive element to reduce friction between the drive element and the guide bushing 8. The guide element may eliminate contact between the drive element and the guide bushing 8. The guide element may be circular, ring-shaped, or implemented as a concentric lead element extending from the inside of the catheter. Preferably, the guide element has a low friction index to enable optimal guidance and force transmission. The guide element reduces bending forces and, ultimately, vibrations during delivery. The guide element centers the drive wire within the guide bushing 8, thereby preventing the drive wire within the guide bushing 8 from bending or buckling beyond the bend of the guide bushing 8. The guide element is preferably coated with a PTFE coating to reduce friction between the drive wire and the guide element.

[0061] The force-limiting element 16 has a distal end 18 and a rearward end 17. The distal end 18 is connected to the guide rod 5, and the rearward end 17 is connected to the drive mechanism 24. Optionally, the rearward end 17 is connected to the drive mechanism 24 via a piston 27. The force-limiting element 16 may be fixed to the guide rod 5 at the distal end 18 and / or fixed at the rearward end of the piston 27.

[0062] The force-limiting element 16 may include a deformable element. The deformable element may be deformable by bending and / or buckling. The deformable element may be embodied as a buckling element 16, more particularly, a buckling wire. The buckling element 16 is elongated in the longitudinal x-direction and configured to buckle when a force exerted by the drive mechanism 24 on the carrier 4 in the longitudinal x-direction (or vice versa) exceeds a predetermined force threshold. When the exerted force exceeds the predetermined force threshold, the buckling element 16 buckles (i.e., suddenly deflects laterally in the yz-direction), causing an abrupt interruption of the force applied to the carrier 4. The buckling element 16 may have a circular, elliptical, rectangular, and / or substantially linear cross-section. The buckling element 16 may be preformed.

[0063] Buckling element 16 is configured to return to its original shape (i.e., linear) when the force no longer exceeds the predetermined threshold force and / or when actuation tip 7 returns to a retracted position. Preferably, buckling element 16 is capable of buckling multiple times without being damaged, broken, or otherwise rendered inoperable, thereby allowing for continued operation of surgical device 1 even after the predetermined force threshold is exceeded.

[0064] Buckling element 16 is further configured to transmit translational forces applied by the drive mechanism without substantial damping (e.g., without elastic deformation or damping) before a predetermined force threshold is met, thereby ensuring direct force transmission during normal operation.

[0065] The buckling element 16 is preferably configured to buckle in the y-direction, and to this end, the buckling element 16 may have a cross-sectional shape that has a greater elongation in the z-direction than in the y-direction, for example, a rectangular cross-sectional shape that is elongated in the z-direction.

[0066] Buckling element 16 is preferably a metal such as Nitinol (a nickel and titanium alloy).

[0067] The predetermined force threshold may result from the type of material, the shape (i.e., lateral cross section and longitudinal extension), the fastening method, and / or any treatment or operation of the force-limiting element 16 (especially the buckling element), which may include bending, preforming, prestressing, annealing, etc.

[0068] The force-limiting element 16 is configured to have a predetermined force threshold in the range of 1N-20N, preferably 2N-10N, more preferably 4N-8N, and most preferably 5N.

[0069] The predetermined force threshold ensures that the working tip 7 is not damaged during surgery through accidental collision with hard tissue (e.g. bone) or other surgical instruments (e.g. scalpels) present at the surgical site, thereby reliably preventing damage to hard tissue and preventing breakage of the working tip 7 of the felt needle 6, which could result in the working tip 7 or parts thereof becoming lodged in the soft tissue of a human or animal.

[0070] FIG. 4 is an enlarged view of section A1 of FIG. 3, showing the distal end of the carrier 4. In particular, the felting needles 6 attached to the distal end of the guide rod 5 are visible, along with the channel 23 in the guide rod 5. The guide rod 5 has a generally rectangular side cross-section with filleted edges. A guide surface 30 is shown near the distal end of the guide rod 5; however, this guide surface 30 does not completely surround the guide rod 5, leaving a gap to allow air to move longitudinally during operation of the surgical device 1. The channel 23 is shown in the form of an elongated recess in the surface of the guide rod, terminating at the distal end near the distal end of the guide rod 5. The distal end of the channel 23 is in the portion of the guide rod 5 where the guide surface 30 is located.

[0071] The felting needles 6 are 5 to 50 mm in length, preferably 10 to 40 mm, most preferably 15 to 30 mm in length, and terminate at their distal ends in working tips 7 which are described in more detail with reference to FIG.

[0072] The felting needles 6 may have a circular, oval, rectangular, and / or other cross-section. Additionally, the felting needles 6 may include a helical screw shape.

[0073] The felting needle 6 may include protrusions and / or recesses for felting on its outer surface, specifically designed to transport some of the fibers into the soft tissue during surgery. These protrusions and / or recesses may be in the form of barbs or hooks. If the felting needle 6 has a rectangular cross section or a helical thread shape, the protrusions and / or recesses may be located on the edge of the felting needle 6.

[0074] Figure 5 is an enlarged view of section A2 of Figure 4, showing the working tip 7 of the felting needle 6. The illustrated working tip 7 has a shape similar to a flathead screwdriver and is shown by way of example only. Other working tips 7 may include a Phillips-shaped tip, a star-shaped tip, etc. The illustrated working tip 7 has an essentially flat end 41. The flat end 41 is joined to the outer surface 40 of the working tip 7 by transitional lateral beveled surfaces 42, 43.

[0075] The flat end 41 may have a rough surface configured to capture fibers. The flat end 41 may have protrusions and / or recesses configured to capture fibers. The protrusions and / or recesses may have a width of 0.005 to 0.1 mm. The protrusions and / or recesses may have a depth of 0.005 to 0.1 mm. The protrusions and / or recesses may have a tapered shape, in particular they may be semicircular, V-shaped, or U-shaped.

[0076] In a preferred embodiment, the flat end 41 at the distal end has a first width perpendicular to the longitudinal direction of the felting needle 6 of at most 1 mm. In a preferred embodiment, the first width is at most 0.5 mm. Particularly preferred, the first width is at most 0.4 mm. Most preferred, the first width is at most 0.3 mm. These dimensions are particularly suitable for capturing fibers of nonwoven fabrics and transporting them to soft tissue. As mentioned above, these fibers become entangled with the soft tissue. If the distal end of the felting needle is too large, too many fibers will be captured at the same time and pushed toward the soft tissue. This will only injure the soft tissue, pushing too many fibers, compared to capturing a few fibers or individual fibers pulled from a single felt.

[0077] In further embodiments, the first width is at least 0.02 mm, at least 0.03 mm, at least 0.04 mm, or at least 0.05 mm. These minimum widths ensure that the fibers can be reliably captured by the flat end 41. If the first width is small, the felting needles 6 may penetrate the felt without capturing any or only a few fibers, resulting in no or poor adhesion. Furthermore, if the first width is below these values, the felting needles 6 may possibly cut the fibers.

[0078] The flat end 41 may also have a second width perpendicular to the longitudinal axis of the felting needle 6 and perpendicular to the first width. The second width may be at least 0.01 mm, at least 0.02 mm, at least 0.03 mm, at least 0.04 mm, or at least 0.05 mm. Similar considerations apply as for the first width.

[0079] Surface roughness may be expressed using a mean linear roughness of 3.2 μm or more, 2.5 μm or more, 2.0 μm or more, 1.5 μm or more, or 1.0 μm or more. The mean linear roughness can be understood as the deviation of the surface from the average height. The roughness may also be the arithmetic mean value of the roughness profile determined from the deviation around the centerline within the evaluation length. The roughness of the distal end, especially the flat end 41, allows individual fibers to be captured and transported.

[0080] 6 is an enlarged view of section B of FIG. 3, showing the rearward end of carrier 4, and in particular the rearward end of guide rod 5. Channel 23 on the outer surface of guide rod 5 extends to the end of guide rod 5. Guide surface 30 is located on the outside of guide rod 5 near its rearward end. Guide rod 5 is connected to the distal end of force-limiting element 16, which extends partially into guide rod 5 for a secure mechanical connection.

[0081] Also shown are two pairs of recesses 29 in the guide rod 5. The recesses 29 are in a portion of the guide rod 5 into which the force-limiting element 16 extends. The recesses 29 extend from the outer surface of the guide rod 5 to the force-limiting element 16. Of the pair of recesses 29, a first recess 29 extends from an opposite surface of the guide rod 5 relative to the second recess 29.

[0082] Figure 7 shows a perspective cutaway view of the surgical device 1. Parts C and D are described in more detail with reference to Figures 8 and 9, respectively.

[0083] 8 shows the tip of the guide bush 8 in which the guide rod 5 and the felting needle 6 are positioned in the retracted position. The guide bush 8 has a cylindrical shape and surrounds the guide rod 5.

[0084] The guide rod 5 is slidably engaged with the inner surface of the guide bush 8, in particular at the guide parts 30, allowing the reciprocating movement of the felting needles 6 in the longitudinal x-direction. The gap between the two guide parts 30 allows air to move through the guide rod 5. The channel 23, which terminates in an area of ​​the guide parts 30, further allows air to move inside the guide rod 5.

[0085] The aforementioned gap between the guide part 30 and the channel 23 also allows sterilizing fluid to easily flow inside the guide bushing 8, thus allowing good sterilization.

[0086] The guide bushing 8 includes a guide bushing collar 26 at its distal end, which may be a separate part from or may be formed integrally with the guide bushing 8. The guide bushing collar 26 defines an opening 11 through which the felting needle 6 moves when the surgical device 1 is operated. The guide bushing collar 26 is designed to longitudinally guide the felting needle 6 during its reciprocating motion. The guide bushing collar 26 defines a longitudinally extending cylinder through which the felting needle 6 moves. The cylinder terminates at the distal end of the opening 11 and has a diameter greater than the diameter of the felting needle 6.

[0087] The guide bushing collar 26 has a transition bevel surface adjacent the cylinder that is designed to guide the felting needle 6 through the cylinder and out through the opening 11 as the felting needle 6 moves from the retracted position to the extended position.

[0088] The guide bushing collar 26 has a curved outer surface at its tip.

[0089] FIG. 9 shows section D of FIG. 7 in more detail, particularly the frame 21, the rear end of the guide rod 5 of the carrier 4, and the drive mechanism 14. As shown, the drive mechanism 14 includes an adapter 24 configured to engage an external actuator 25 (not shown). The external actuator provides rotational motion in the x-y plane. The upper portion of the adapter 24 is positioned rearward of the frame 21 and includes a sliding pin attached to a rotating wheel (a rotating disk or crank is also envisioned). The sliding pin is connected to a scotch yoke that converts the rotational motion into a reciprocating motion of a piston 27, which is connected to the force-limiting element 16. Alternatively, instead of a scotch yoke, a piston rod can be connected to the sliding pin and pivotally coupled to the piston 27. A direct connection between the force-limiting element 16 and the sliding pin is also possible, for example, by terminating the rear end of the force-limiting element 16 in a loop or ring that engages the sliding pin.

[0090] A recess 22 located at the distal portion of the frame 21 provides space for the force-limiting member 16, such as the buckling element 16, to buckle in the y-direction when the force exceeds a predetermined force threshold.

[0091] The rear and distal portions of the frame 21 are separated by a bearing 32, which is longitudinally disposed and configured to at least partially receive the piston 27 and / or the force-limiting element 16. The bearing 32 guides the piston 27 and / or the force-limiting element 16 longitudinally.

[0092] FIG. 10 shows upper and lower cutaway views of the surgical device 1 in three different positions.

[0093] In FIG. 10( a), the carrier 4 of the surgical device 1 is in the retracted position 10, with the working tip 7 of the felting needle 6 not extending beyond the opening 11. This is the default state when the surgical device 1 is not activated. A biasing member (not shown) ensures that even when an external actuator is connected, the biasing force of the biasing member will return the carrier 4 to the retracted position 10 when the external actuator is turned off. In the retracted position 10, the carrier's guide rod 5 is partially in the recess 22, and the piston 27 is almost fully extended from the bearing 32 toward the rear end of the surgical device 1. The slide pin of the drive mechanism 14 is in its rearmost position.

[0094] 10(b), the carrier 4 of the surgical device 1 is in the extended position 9. The working tip 7 of the felting needle 6 extends beyond the opening 11. In the extended position 9, the piston 27 is almost completely in the bearing 32.

[0095] 10(c) shows the situation when the working tip 7 of the felting needle 6 hits a hard object and the force acting on the working tip 7 of the needle exceeds a predetermined force threshold. The force-limiting element 16 buckles and deflects, particularly in the y-direction, thereby causing an intermediate interruption in the force transmission between the drive mechanism 14 and the felting needle 6. This prevents breakage of the felting needle 6 (particularly the working tip 7) and / or damage to the hard object. When the force no longer exceeds the predetermined force threshold, for example because the hard object is removed or the felting needle 6 is retracted, the buckling element 16 returns to its "unbuckled" or initial state. The buckling element 16 can then buckle again.

[0096] FIG. 11 shows, in the upper chart, the displacement of the felting needle, specifically the working tip 7 of the felting needle 6, as a function of the longitudinal displacement of the drive mechanism. At point 1, the working tip 7 is fully retracted. The path between points 1 and 2 shows the working tip 7 being extended. At point 2, the working tip 7 stops extending because it contacts a hard object that it cannot penetrate. On the path between points 2 and 3, even though the drive mechanism 14 continues to extend longitudinally, the working tip 7 does not extend further. This is because the force that the drive mechanism 14 exerts on the working tip exceeds a predetermined force threshold, thereby engaging the force-limiting element 15. At point 3, the drive mechanism 14 has reached its maximum longitudinal extension. At point 4, the drive mechanism 15 begins its return path. Between points 4 and 5, the drive mechanism 15 retracts, but the working tip 7 remains stationary. At point 5, the actuation tip 5 loses contact with the hard object and follows the displacement of the drive mechanism 14 back to the endpoint 6. The forward and return paths do not necessarily overlap due to, for example, hysteresis in the force-limiting element 15.

[0097] In the lower chart, the force on the working tip 7 of the needle 6 is illustrated as the needle follows the path shown in the upper chart. Between points 1 and 2, the working tip 7 moves through soft tissue, as indicated by the irregular force exerted on the working tip. At point 2, the working tip 7 encounters a hard object, such as hard tissue (e.g., bone) or another surgical instrument (e.g., a scalpel). The force exerted on the working tip 7 meets a predetermined force threshold, and the force-limiting element 15 engages, thereby preventing the working tip 7 from exerting a force on the hard object beyond the predetermined force threshold. Further displacement by the drive mechanism 14 from points 2 to 3 is met with a rapid decrease in the force exerted by the working tip 7 on the hard object, as indicated by the locus of the force curve between points 2 and 3. The force may rapidly decrease to a minimum force level, which may be near zero. During the return path, i.e., from point 4 to point 5, the force exerted on the actuating tip 7 may follow a different path than the forward path (i.e., from point 1 to point 3) due to hysteresis. For example, the force on the actuating tip 7 may be negative (i.e., directed backward) for at least a portion of the return path. In particular, the force may be negative between points 5 and 6, during which the actuating tip 7, which may be partially embedded in a hard object, is pulled out of the hard object and then pulled back through soft tissue. Notably, the force-limiting element 16 may not be engaged during the return path, such that the magnitude of the force on the path between points 4 and 6 may exceed a predetermined force threshold. This allows the actuating tip 7 to be removed by the drive mechanism 14 even if it becomes embedded or stuck. [Explanation of symbols]

[0098] 1 Surgical equipment 4. Career 5 Guide rod (carrier) 6 felting needles (carrier) 7. Working tip (needle) 8 Guide bush 9 Extended position 10 Retract position 11 Opening (guide bush) 12 Distal end (guide rod) 13 Rear end (guide rod) 14 Drive mechanism 15 Force-limiting elements 16 Buckling elements / buckling bars 17 First end (buckling element) 18 Second end (buckling element) 19 Distal end (guide bush) 20 Rear end (guide bush) 21 Frame (surgical device) 22 Recess (frame) 23 channels 24 Adapter (drive mechanism) 25 Actuators 26 Guide bush collar 27 Piston rod 28 Outer housing 29 Recess (guide rod) 30 Guide surface (guide rod) 31 biasing member 32 Bearings 40 Outer shaft (operating tip) 41 Flat end 42 Bevel

Claims

1. A surgical device (1) for attaching fibers of a nonwoven fabric to soft tissue of a human or animal by releasing some of the individual fibers of the nonwoven fabric and transporting them to the soft tissue of a human or animal, the device comprising: a carrier (4) extending in a longitudinal direction (x), comprising a guide rod (5) and a felting needle (6) attached to the distal end (12) of said guide rod (5), wherein: b) the guide rod (5) and the felting needle (6) are at least partially disposed in a guide bush (8), and the felting needle (6) is reciprocable between i and ii below; i. an extended position (9) in which the working tip (7) of said felting needle (6) projects beyond an opening (11) located at the distal end of said guide bush (8); ii. a retracted position (10) in which the working tip (7) of the felting needle does not protrude beyond the opening (11) located at the distal end of the guide bush (8); c) the guide rod (5) has a rearward end (13) that is coupled to a drive mechanism (14) via a force-limiting element (15), the force-limiting element limiting the force applied by the drive mechanism (14) to the guide rod (5) to a predetermined force threshold when the actuating tip (7) moves from the retracted position (10) to the extended position (9) during actuation.

2. 2. The surgical device (1) of claim 1, wherein the force-limiting element is further configured not to limit the force applied to the guide rod (5) by the drive mechanism (14) to a predetermined force threshold when the working tip (7) moves from the extended position (9) to the retracted position (10).

3. 3. The surgical device (1) according to claim 1 or 2, wherein the force-limiting element (15) comprises a deformable element (16) that deforms when a predetermined force threshold is reached in the longitudinal direction (x), thereby interrupting the transmission of forces in the longitudinal direction (x).

4. 4. The surgical device (1) of claim 3, wherein the deformable element (16) is a buckling element (16) that stretches between a first end (17) and a second end (18) and deforms in a lateral direction (y, z) when a predetermined force threshold is reached.

5. 5. The surgical device (1) according to claim 4, wherein the buckling element (16) is fixed at the first end (17) and / or the second end (18).

6. The surgical device (1) according to any one of claims 3 to 5, wherein the buckling element (16) is pre-shaped such that the buckling element (16) buckles when the predetermined force threshold is reached during actuation.

7. A surgical device (1) according to any one of the preceding claims, wherein the working tip (7) of the felting needle (6) comprises delivery means supporting the delivery of individual fibre portions into soft tissue.

8. 8. The surgical device (1) of claim 7, wherein the delivery means comprises an essentially flat end (41) disposed at the distal end of the working tip (7) and / or barbs along the outer shaft (40) of the working tip (7).

9. The surgical device (1) according to any one of claims 1 to 8, comprising a frame (21) on which the guide bush (8) and the drive mechanism (14) are mounted.

10. 10. The surgical device (1) according to claim 9, wherein the frame (21) comprises a recess (22) in which the force-limiting element (15) is arranged between the rear end of the guide bush (8) and the drive mechanism (14).

11. A surgical device (1) according to any one of the preceding claims, wherein a channel (23) extends in the longitudinal direction (x) between the guide rod (5) and the guide bush (8).

12. 12. The surgical device (1) according to claim 11, wherein the guide rod (5) comprises the channel (23) extending in a longitudinal direction (x).

13. The surgical device (1) according to any one of the preceding claims, wherein the drive mechanism (14) comprises an adapter (24) for connecting the drive mechanism (14) to an external actuator (25).

14. The surgical device (1) according to any one of claims 1 to 13, wherein the opening (11) is formed by a guide bush collar (26) having an inner diameter smaller than the inner diameter of the guide bush, and wherein the guide bush collar (26) includes a transition surface at a distal end and / or a rear end.

15. A surgical device (1) according to any one of claims 1 to 14, wherein the felting needles (6) are made from metal and the guide rod (5) is made from an injection-molded plastic material that at least partially encompasses the felting needles (6) opposite the working tip (7).

16. 16. The surgical device (1) according to claim 15, wherein the force-limiting element (15) and the felting needle (6) are integrally formed and extend through the guide rod (5).

17. 17. The surgical device (1) according to claim 15 or claim 16, wherein the guide rod (5) comprises at least two opposing recesses (29) in which a portion of the force limiting member (6) is positioned.

18. The surgical device (1) according to any one of the preceding claims, wherein the force-limiting element (15) is connected to the drive mechanism (14) by a piston rod (27).

19. 19. The surgical device (1) according to claim 18, wherein the piston rod (27) is linearly guided in a bearing (32) of the frame (21).

20. A surgical device (1) according to any one of the preceding claims, wherein the frame (21) is at least partially enclosed in an outer housing (28).

21. A surgical device (1) according to any one of the preceding claims, wherein the guide rod (5) comprises at least two guide surfaces (30) spaced apart from one another in the longitudinal direction (x).

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