Surgical minimally invasive instrument

Abstract

The invention provides an instrument (1) for minimally invasive surgery, preferably for laparoscopy, comprising: a shaft tube (11); a joint part (12) which is connected to the shaft tube (11) at a distal end of the shaft tube (11) in such a way that the joint part (12) is pivotable about a rotation axis (A) with respect to the shaft tube (11); and an inner part (13) which is partially inserted into the shaft tube (11) and is axially movable within the shaft tube (11) via a proximal actuator mechanism (15, 16); wherein the inner part (13) is coupled at its distal end (133) to the joint part (12) in such a way that an axial movement of the inner part (13) causes a pivoting of the joint part (12) about the axis of rotation (A).

Description

Technical field

[0001] The present invention relates to a medical instrument for minimally invasive surgery, in particular a laparoscopic instrument, with improved construction, in particular with improved articulation mechanics. Background of the Revelation

[0002] Medical instruments for minimally invasive surgery are known from the prior art. Such instruments typically have an elongated (shaft-like) structure, with a proximal end / end section at which a user, usually a surgeon, manipulates the instrument, and a distal end / end section (also called the "application end") to which a functional unit (effector) is attached, for example a cutting and / or sealing tool (seal and cut instrument). A small-diameter shaft tube typically runs between the proximal end and the distal end, which can be inserted into a patient's body, for example, through a trocar sleeve (or the working channel of an endoscope).

[0003] In this way, the functional unit can be deployed inside a patient, while the distal end of the instrument remains outside for the user to manipulate. This type of surgery is minimally invasive in the sense that only the smallest possible opening of the patient's body needs to be provided.

[0004] Due to the elongated design of the instrument, it is challenging to reliably and precisely translate the user's highly accurate settings and actions on the proximal side into actions of the functional unit. While a robust instrument design is important for this, a compact design, low weight, and easy handling are also valued.

[0005] In addition, articulation of a distal part of the instrument, which can be referred to as a joint part, is often required. This articulation of the joint part can serve to align a functional unit of the instrument during a surgical procedure. State of the art

[0006] Minimally invasive surgical instruments of the type described above are known from the prior art. They have a proximal handle connected to an instrument shaft (rigid or flexible). The instrument shaft and the handle are often connected or connectable via a rotary coupling to rotate the shaft relative to the handle about its longitudinal axis. An instrument head is mounted at the distal end of the shaft, allowing it to rotate and / or tilt, and an effector is mounted, in particular supported, on the head.

[0007] To operate the instrument head, actuators (e.g., buttons, levers, handwheels, etc.) are provided on the handle, which is preferably designed as a grip. These actuators are operatively connected to the instrument head via a gear train. Furthermore, actuators for operating / operating the effector are arranged on the handle.

[0008] The gear train and the connecting lines to the effector are usually laid within the instrument shaft, which is designed in a tubular shape for this purpose. In principle, the gear train can be a rotary or push / pull rod, the respective movement of which is transformed into a pivoting and / or rotary movement of the instrument head. This requires a transformation mechanism, for example in the form of force deflection elements or the like, in the area of ​​the distal instrument head, which is usually mechanically complex and expensive. Since several parts must always work together in such a movement transformation mechanism (serially, i.e. in the direction of the gear train), this inevitably results in a chain of tolerances, which ultimately leads to the handling of the instrument becoming vague and inaccurate for the operator. A higher susceptibility to failure must also be expected. Summary of Revelation

[0009] It is therefore the objects and aims of the present disclosure to overcome the above-mentioned challenges of the prior art and to satisfy the above-mentioned existing needs, and in particular to provide an improved articulable instrument for minimally invasive surgery, preferably a laparoscopic instrument, which combines a small design and good handling with precise operability.

[0010] The objects of the present disclosure are achieved by the features of claim 1.

[0011] Accordingly, the invention provides an instrument for minimally invasive surgery, preferably for laparoscopy, comprising: a shaft tube; a joint part which is connected to the shaft tube at a distal end / end section of the shaft tube in such a way that the joint part is pivotable (or articulated) with respect to the shaft tube about a rotation axis (extending at right angles to the shaft tube axis); and an inner part which is partially inserted into the shaft tube (and optionally partially into the joint part) and is axially movable within the shaft tube via a proximal actuator mechanism; wherein the inner part is coupled at its distal end to the joint part in such a way that an axial movement of the inner part causes a pivoting (or: articulation) of the joint part about the axis of rotation.

[0012] A fundamental idea of ​​the present disclosure is that through a clever design of an inner part (or "inlay") as well as a distal articulation mechanism and a proximal actuator mechanism that interact with the inner part, both mechanical actuation of the instrument is enabled and structural stability is provided. Furthermore, both a reduction in component numbers and a simplification of the mechanics are realized.

[0013] The terms “proximal” and “distal” always refer to the perspective of the user of the instrument, who handles the instrument at its proximal side so that a functional unit at its distal end can interact with the patient.

[0014] In this context, an "axial" movement is understood to mean a movement along a longitudinal axis, in particular a movement of the elongated inner part within and relative to the elongated shaft tube. The axial direction can also be referred to as the "longitudinal direction." A "transverse" direction is perpendicular to the longitudinal axis.

[0015] Advantageous embodiments are claimed in the subclaims and are explained in particular below.

[0016] The shaft tube can preferably have an external thread in the region of a proximal end (the thread preferably does not extend all the way to the proximal shaft end, but is provided as close as possible to the proximal shaft end), into which an internal thread of an actuator element engages. The actuator element can be coupled to a driver of the instrument in such a way that, upon a rotational movement of the actuator element around the shaft tube (or around the external thread of the shaft tube), the driver moves axially, in particular exclusively axially. An (inwardly directed) nose of the driver can be configured to engage through an opening in the shaft tube into a pocket (or recess) in the inner part and, upon an axial movement of the driver, to cause an axial movement of the inner part. In this way, a space-saving rotational movement can be converted into a desired axial movement of the inner part at the proximal end of the instrument.According to the invention, this axial movement is converted into a pivoting (or articulation) of the joint part.

[0017] The coupling of the shaft tube, actuator element, driver, and inner part can particularly preferably be designed to be self-locking. Thus, the pivoted position of the joint part is advantageously maintained until it is changed again by a renewed rotational movement of the actuator element. This enables high precision in guiding a functional unit at the distal end of the instrument, especially at the distal end of the joint part.

[0018] The actuator element can advantageously be formed on its outer surface with a gear structure (or: as a gear). In this way, a user input can be detected or converted in a rotational manner and transmitted to the actuator element in a manner that is appropriate for the application.

[0019] The actuator element (preferably formed with the gear structure) can be constructed in multiple pieces and arranged assembled around the shaft tube. This multi-piece design offers advantages during manufacturing, e.g., during injection molding, but also during assembly around the shaft tube, as the actuator element does not have to be threaded onto the shaft tube but can be placed around the shaft tube in any assembly step. The multi-piece actuator element can be held together in the instrument, for example, by a circumferential retaining ring and / or a part of the driver, such as an annular projection of the driver.

[0020] According to a preferred embodiment, the inner part has at least one elongated hole at its distal end, through which an axis coupled to the joint part is guided, which axis is spaced from the axis of rotation of the joint part and arranged parallel to it. Particularly preferably, the inner part has two (or more) parallel and aligned elongated holes at its distal end, through which the axis coupled to the joint part (which can, for example, be fixedly connected to the joint part) is guided. In this way, the pivoting movement is guided even better and thus even more stable. As an alternative to multiple elongated holes, a single elongated hole can also be designed in the form of a through-hole with an elongated hole-shaped cross-section.

[0021] The axis (for example, fixedly connected to the joint part) which is guided through the at least one elongated hole of the inner part is advantageously formed by a transversely arranged cylindrical pin which in turn is guided through a respective circular through-bore through a respective arm of two proximal arms of the joint part.

[0022] The inner part preferably has, at least in sections, at least one recess, in particular a longitudinal groove, running along its longitudinal axis, in which a force transmission element (particularly preferably a tension band for actuating a jaw part of the instrument) and / or a blade and / or an electrical supply and / or signal line is arranged. The inner part can have a plurality of recesses, in particular longitudinal grooves, running along the longitudinal axis, wherein at least one tension band is arranged in one or more of them and / or at least one electrical supply and / or control line is arranged in one or more of them and / or at least one blade is arranged in one or more of them. The respective recess, in particular a longitudinal groove, can preferably represent (or provide) a guide for the element arranged therein.

[0023] An electrical supply power may, for example, be configured to carry an alternating current (RF) signal for powering an AC-powered sealing tool, or a direct current for powering and / or controlling an electric motor.

[0024] A longitudinal groove is understood here in particular to mean an elongated recess on an outer side of an elongated object, which extends along (ie parallel to) the longitudinal axis of the elongated object (e.g. the elongated inner part), preferably over a large part of the elongated extent of the elongated object (ie over 50% of the elongated extent, over 75% of the elongated extent or even more). Unless otherwise immediately apparent, the term "longitudinal" in the present disclosure always refers to a longitudinal axis that extends from the proximal side to the distal side.

[0025] The inner part (or inlay) thus fulfills a dual function in the present inventive concept: on the one hand, it is part of a force transmission mechanism that transmits an actuation of the proximal actuator mechanism to the joint part in order to pivot (or articulate) it. On the other hand, it is designed to guide components or elements of the instrument that run longitudinally (i.e., along the instrument's longitudinal axis).

[0026] Advantageously, the instrument also has a functional unit at a distal end of the joint part and / or a handling unit at the proximal end of the shaft tube. The handling unit can be integrated into the proximal actuator mechanism or vice versa. Preferably, the functional unit can be actuated by means of the handling unit. The functional unit can be, for example, a cutting and / or sealing tool, a jaw part, and / or the like. Character list

[0027] The present disclosure will be explained in more detail below using preferred embodiments with reference to the accompanying figures. They show: Fig. 1 a schematic three-dimensional view of a portion of a (medical) instrument according to an embodiment of the present invention; Fig. 2 a schematic three-dimensional view of a detail of the section from Fig. 1 from a different direction; Fig. 3 is a further schematic three-dimensional view of a further detail of the section from Fig. 1 from yet another direction; Fig. 4 a schematic side view of the section from Fig. 1 when individual elements are partially hidden; Fig. 5 a schematic cross-sectional view through an internal part of the instrument from Fig. 1-4; Fig. 6 a schematic longitudinal sectional view of a proximal section of the instrument from the Fig. 1-5; Fig. 7 a schematic three-dimensional view of an actuator element from Fig. 6; Fig. 8 a schematic overview longitudinal section through the instrument from Fig. 1-7 and Fig. 9 a side view of the (medical) instrument

[0028] The figures are schematic in nature and are intended only to assist in understanding the present disclosure. Like elements are designated by like reference numerals. Detailed description of preferred embodiments

[0029] Fig. 9 shows the basic structure of a surgical instrument of minimally invasive design according to the disclosure and in particular a so-called laparoscopic (electric) sealing and cutting instrument.

[0030] This has a proximal handle with a number of built-in actuating elements and / or actuators (e.g., actuating levers for opening and closing a distal jaw part, triggers for applying current to the jaw part, etc.), to whose distal end a tubular instrument shaft is mounted or mountable. The instrument shaft has a distal end section to which an instrument head is mounted / hinged in a bendable / pivotable manner. The instrument head has an effector, in this case in the form of two scissor- / tweezer- / forceps-like movable (tissue) intervention branches (jaw part), which are mounted / hinged accordingly on the instrument head. For example, the intervention branches can be coupled to one another in their respective central section via a hinge pin, wherein the hinge pin is further fastened or mounted in the instrument head.The distal sections of the intervention branches (distal to the hinge pin) are provided with or formed with tissue-engaging elements, for example, electrodes or electrode areas to seal (and / or cut) tissue clamped between them and / or a cutting blade to sever tissue. The proximal sections of the intervention branches (proximal to the hinge pin) are provided with or formed with articulation elements, for example, eyelets, forks, etc., to each of which a pull or push cable is attached. Finally, electrical cables are routed in / on the instrument head, which are connected / electrically connected to the electrodes or to the electrical sections of the branches.

[0031] Both the pull / push cable and the electrical cables are routed proximally to the instrument handle within the instrument shaft and are connected / coupled there to the corresponding actuating elements / actuators for optionally bending the instrument head, opening and closing the effector (in this case the jaw part) and actuating the electrode(s).

[0032] In this respect, the basic design of the surgical instrument corresponds to the state of the art described at the beginning, although this design, for example of the handle or the instrument head, can of course also be modified within the framework of the known state of the art.

[0033] Fig. 1 shows a schematic three-dimensional view of a distal end portion of the surgical / medical instrument 1 according to an embodiment of the present disclosure, in which a joint is arranged.

[0034] The surgical / medical instrument 1, here for example a laparoscopic instrument, basically has an instrument shaft, in this case a shaft tube 11, which is coupled in an articulated / hinge-like manner to a joint part / instrument head 12. The joint part / instrument head 12 is here at a distal end (see distal direction D in Fig. 1) of the shaft tube 11, and the shaft tube 11 in turn at a proximal end (see proximal direction P in Fig. 1) of the joint part 12.

[0035] The distal end of the shaft tube 11 terminates in two parallel arms 111 of the shaft tube 11, each of which contains a circular opening 112. In other words, the shaft tube 11 is forked at its distal end section, creating two parallel-spaced arms or tabs 111, which are preferably resiliently bendable / radially expandable outward, comparable to a spring tongue. Each of these arms 111 is provided with a through-bore oriented transversely to the shaft tube axis, the bore axes A of which are aligned and which are intended to receive hinge pins.

[0036] Fig. Figure 2 shows the proximal end of the joint part / instrument head 12 in a further schematic three-dimensional view (perspective view). It can be seen that the proximal end of the joint part 12 also ends in two parallel arms 121 of the joint part 12, on the outside of which a round outer pin 122 is formed. In other words, the instrument head consists of a sleeve whose proximal end section is divided by an axial notch into two parallel, spaced-apart arms, legs, or tabs 121, which are preferably resiliently bendable, comparable to a spring tongue. On each of these tabs 121, a radially outwardly projecting pin or bolt 122 is formed, the mutually aligned center axes of which intersect the longitudinal axis of the sleeve at right angles.Furthermore, a through-hole 123 is provided on each tab 121, which are also aligned with one another and are offset off-center and proximally with respect to the respective bolt 122, so that a lever arm is formed between the respective through-hole 123 and the associated bolt 122.

[0037] The dimensions of the arms 111 of the shaft tube 11 and the arms 121 of the joint part 12 are selected such that the arms 111 of the shaft tube 11 can be guided radially outwardly over the arms 12 of the joint part 12 and the two outer pins 122 by being bent apart moderately and elastically. The dimensions of the circular openings 112 on the arms 111 of the shaft tube 11 are selected such that, with appropriate overlap, the round outer pins / bolts 122 snap or engage into the openings 122 (spring-elastic), thus holding the joint part 12 in an articulated / hinge-like manner by the arms 111 of the shaft tube 11. In other words, the distance between the two arms 111 of the shaft tube is as large as the outer dimension of the joint piece 12 at the corresponding point, and the arms 111 are designed to be elastically deformable.In the manner described above, the joint part 12 is secured with almost no play and only allows a rotation / pivoting movement of the joint part 112 about a rotation axis A (or: articulation axis), which is defined jointly by the outer pins / bolts 122.

[0038] The round outer pins 122 and the circular openings 112 form a pivot joint, by means of which the joint part 12 can be pivoted (or articulated) relative to the shaft tube 11, specifically about a rotation axis A which is arranged concentrically with the outer pins 122 and the circular openings 112.

[0039] In Fig. 2 also clearly shows that the circular through-bore 123 is formed through each of the two arms 121 of the joint part 12, with the two through-bores 123 being aligned with one another. Each circular through-bore 123 is spaced from the adjacent outer pin 122. The circle center of the respective through-bore 123 is closer to the proximal end of the joint part 12 than the circle center of the respective outer pin 122. Furthermore, the respective through-bore 123 is offset with respect to the respective outer pin 122 in a direction that is perpendicular to the rotational axis A and perpendicular to a longitudinal axis of the joint part 12. Fig. 2, the through hole 123 is therefore offset from the outer pin 122, for example, not only to the left but also downwards.

[0040] In Fig. 1, it can be seen that the instrument 1 also has an inner part (insert) 13 (or, in English, "inlay") formed separately from the shaft tube 11. This inner part 13 is arranged partly within the shaft tube 11 and partly within the joint part 12, more precisely: between the two arms 121 of the joint part 12, which in turn are encompassed by the two arms 111 of the shaft tube 11. As in Fig. 1, the space between the two arms 121 of the joint part 12 can have a rounding in longitudinal section, or in other words, a circular segment-shaped end, in which a distal end of the inner part 13 is received, so that the inner part 13 does not hinder the pivoting of the joint part 12 with respect to the shaft tube 11.

[0041] In other words, for the function of the instrument head itself (namely, pitching motion) as well as for the function of the effector (namely, an opening and closing movement, particularly pincer movement, and the application of electrical current), mechanical forces and electrical energy must be reliably and precisely delivered to the instrument head. Essentially, the only space available for laying the corresponding cables and power transmission lines is the hollow space formed by the shaft tube.

[0042] For this reason, the present disclosure provides for the use of the inner part 13. This is essentially a preferably fully profiled tension / compression rod which is guided in the shaft tube so as to be longitudinally displaceable (the inner part lies circumferentially at least in sections slidingly against the inner wall of the shaft tube) and which has a number of longitudinally extending outer grooves which serve as guide grooves / guide channels for electrical cables and cables. The inner part (inlay) in the form of a tension / compression rod is thus in principle a type of guide aid for the cables and power transmission cables to ensure reliable and precise actuation of the functions of the instrument head or its effector and at the same time also has a quasi-smart function or additional function, namely the inner part provides the power transmission cable for actuating the instrument head orIt represents the pitching movement itself, which in turn is guided by the shaft tube and thus precisely transmits an actuating force from the handle to the instrument head. For this purpose, the inner part preferably extends from the handle to the instrument head and is operatively connected there in such a way that an axial displacement of the inner part relative to the tubular shaft is transformed into a pivoting / tilting / pitching movement of the instrument head.

[0043] Fig. 3 schematically illustrates the distal end / end section 133 of the inner part 13 in detail. In Fig. 3 it can therefore be seen that the distal end / end section 133 of the inner part 13 is offset, ie in particular with a smaller cross section than the preceding (proximal), middle section 138 of the inner part 13. The middle section 138 of the inner part 13, which can for example make up more than 80% or more than 90% of the total length of the inner part 13, advantageously has an outer circumference which is only slightly smaller than the inner circumference of the shaft tube 11, so that the inner part 13 can move freely within the shaft tube 11 in the axial direction, but is guided in a sliding manner by the shaft tube 11 in the radial direction.

[0044] Formed in the distal end / end section 133 of the inner part 13 is a through-hole extending transversely to the longitudinal axis L of the inner part 13, which is arranged radially offset with respect to the longitudinal axis L and thereby forms an elongated hole extending in a direction transverse to the longitudinal axis (preferably tangential direction). The width of the elongated hole corresponds approximately to the diameter of the through-bores 123 formed on the tabs 121 of the joint part 12 (instrument head). Furthermore, the end face of the inner part 13 is beveled and extends obliquely proximally from the distal end tip of the inner part in the region of the elongated hole.

[0045] Fig. Figure 4 schematically shows - with the shaft tube 11 omitted - the articulated connection between the joint part 12 and the inner part 13. A pin 135, for example, cylindrical, is guided through the two through-holes 123 and through the at least one elongated hole 134 in the inner part 13 inserted into the sleeve-shaped joint part 12. Furthermore, the bolts 122 are engaged in the holes 112 of the shaft tube 11, as shown in the Fig. 1. In design position according to the Fig. 1, the shaft tube 11 and the sleeve-shaped joint part 12 extend essentially coaxially. In this orientation, the distal end face, which is inclined proximally, runs between the hinge pin 135 and the bolts 122, as is also the case in the Fig. 1. Due to the leverage effect resulting from the radial distance between bolt 122 and hinge pin 135, the joint part 12 hinged to the shaft tube 11 can be pivoted (or articulated) by a purely axial movement of the inner part 13 within the shaft tube 11, by generating a torque on the joint part 13 by pulling or pushing on the inner part 12 via the pin 135 and the at least one elongated hole 134. If the inner part 13 is moved, for example, axially in the proximal direction P relative to the shaft tube 11, the pin 135 is pushed through the elongated hole 134 (to the right in Fig. 4) is pulled in the proximal direction and thus, due to the offset arrangement (or: due to the eccentric placement) of through-holes 123 and the rotation axis A, a clockwise torque is exerted on the joint part 12. In this way, the joint part 12 can be pivoted (or: articulated) precisely and accurately, since only a single (possibly subject to tolerances) joint / hinge is provided in the force transmission line between the joint part and the inner part. The elongated hole 134 also serves to compensate for the radial movement of the through-holes 123 and the hinge pin 135.

[0046] Before the preferred mechanisms for axial actuation of the inner part 13 are discussed below, the advantageous embodiments of the inner part 13, in particular with regard to its cross section, are described.

[0047] As already explained at the beginning, functional units (effectors) are typically located at the distal end of the joint part 12, for the introduction and handling of which the instrument 1 is used. Such a functional unit can be, for example, a jaw part, a cutting and / or sealing tool, and / or the like. The respective functional unit, or the functional units, are actuated proximally, from outside the patient's body, on the handle. This can be done by electrical supply and / or control signals that supply and / or control one or more electric motors (or other electrical or electronic elements) of the functional unit with electrical current. The electrical supply and / or control signals can be direct current and / or alternating current.

[0048] On the other hand, a more direct, haptic feedback actuation can also be provided. For this purpose, force transmission elements, such as tension bands / cables, can extend from a proximal actuator element on the handle to the distal functional unit (effector). A user can actuate such a force transmission element manually or actuate a motor on the handle, which in turn actuates the force transmission element. Particularly with purely manual actuation, the user receives immediate feedback on what is happening at the distal functional unit, for example, based on the resistance felt. Especially in the latter case, it is necessary that this feedback be as precise and as time-delayed as possible to avoid a spongy actuation sensation.

[0049] Fig. Figure 5 shows a schematic cross-sectional view through the inner part 13, specifically in its middle section 138, i.e., between its proximal end and the distal end 133. The cross-sectional area of ​​the inner part 13 as a whole is roughly circular, with various recesses / longitudinal grooves being formed starting from the circumferential outer side of this circular shape. The inner part 13 has, for example, on its outer side two lateral slot-shaped longitudinal grooves 131 lying in a common plane. This plane virtually divides the cross-section of the inner part 13 into two hemispheres (in Fig. 5: top and bottom). In one of these hemispheres (in Fig. 5: below) two further recesses are formed in the form of bulbous longitudinal grooves 132. The slot-shaped longitudinal grooves 131 and the bulbous longitudinal grooves 132 are arranged in such a way that a (in Fig. 5 vertical) mirror symmetry axis or mirror symmetry plane (along the longitudinal axis L of the inner part 13).

[0050] For example, a blade or an actuating cord for axially displacing a blade mounted in the instrument head, a force transmission element (e.g., a tension band), preferably for actuating the effector (e.g., opening and closing the tissue-engaging branches), an electrical supply and / or signal line (e.g., for the electrodes on the branches), and / or the like can be arranged in the longitudinal grooves 131, 132. The inner part 13 thus also provides a guide for the accommodated elements (cables and force transmission cables), which is thus implemented in a space-saving, simple, and inexpensive manner. For example, a tension band can be arranged in each of the two slot-shaped longitudinal grooves 131, so that the tension bands can exert a symmetrical force on the jaw part or its branches. The bulbous longitudinal grooves 132 can, for example, be provided for electrical supply and / or control lines.In this way, it is prevented that the cables and wires run in an unordered manner in the shaft tube 11 and thus also create unnecessarily high frictional resistances, which can cause actuation hysteresis.

[0051] Fig. Figure 6 illustrates in a schematic longitudinal section the proximal actuation of the inner part 13 for its axial movement, and thus also the pivoting of the joint part 12 with respect to the shaft tube 11, by means of the previously described proximal actuator mechanism. Preferably, the Fig. 6 at least part of the handle of the surgical instrument according to the disclosure,

[0052] Preferably, the axial movement of the inner part 13 is effected in a space-saving manner by a rotational movement of a sleeve-shaped actuator element 15 of the instrument 1.

[0053] For this purpose, the shaft tube 11 has an external thread 114 at its proximal end / end section 119, into which an internal thread 154 of the actuator element 15 engages or is screwed onto it. The actuator element 15 is thus arranged concentrically with respect to the shaft tube 11 and completely surrounds it at its proximal end section. The external thread 114 is preferably cut into the shaft tube 11. Alternatively, however, the external thread 114 can also be slipped onto the shaft tube 11, for example in the form of a sleeve.

[0054] The actuator element 15 is preferably designed on its outer side as a gear (or: with a gear structure 157), as particularly well shown in Fig. 7. The actuator element 15 can alternatively also be designed without a gear structure 157 and then be designed, for example, for manual rotation.

[0055] Fig. 7 shows a schematic three-dimensional view of the actuator element 15, which here, for example, is designed as a gear in its outer contour. The gear grooves of the gear structure 157 are formed along the longitudinal axis of the shaft tube 11, which is identical to the longitudinal axis L of the inner part 13. Thus, for example, the operation of a drive motor that is in operative engagement with the gear can cause a rotational movement of this gear structure 157, which then moves axially along the shaft tube 11 due to the external thread 154 and the internal thread 114.

[0056] As in Fig. 7, the actuator element 15 has a circumferential annular groove 156 in the longitudinal direction before and after the gear structure 157.

[0057] The actuator element 15 is preferably formed in several parts, for example in two parts. Fig. 7 shows, by way of example, a dividing line T between the two components of the actuator element 15, which advantageously runs unevenly, i.e., not within a plane, in order to make the actuator element 15 more robust against displacements and the like. For this purpose, the dividing line T preferably comprises a step S. The overall structure of the actuator element 15 can preferably be held together by circular structures arranged in the circumferential annular grooves 156, which enables simple assembly.

[0058] Alternatively, the actuator element 15 can also be formed as a single piece. In this case, it can be slotted on one side. For assembly, it can be widened at the slot and plugged onto the shaft tube 11. If the external thread 114 is only plugged onto the shaft tube 11 in the form of a sleeve, the actuator element 15 can also be formed as a single piece and without a slot.

[0059] In Fig. 6 shows that a retaining ring 17 engages or is inserted into the proximally arranged circumferential annular groove 156, which holds the two components of the actuator element 15 together. The distally arranged circumferential annular groove 156 is coupled to a driver 16 of the instrument 1.

[0060] The driver 16 is also arranged concentrically to the shaft tube 11 and surrounds it. It has a radially inwardly extending projection, namely an annular projection 165, which is designed and arranged to engage in the distal circumferential annular groove 156 of the actuator element 15. Accordingly, the driver 16 is not only attached to the shaft tube 11, but also to the actuator element 15. In this way, not only is the (possibly) multi-part overall structure of the actuator element 15 additionally held together, but the axial movement of the actuator element 15 is also transmitted to the driver 16. The actuator element 15 and the driver 16 (and possibly further elements) thus form a proximal actuator mechanism.

[0061] The driver 16, in turn, has a radially inwardly projecting nose 161, which engages, in particular in a form-fitting manner, through a radial (or lateral), longitudinally extending recess (slot) 116 in the shaft tube 11 into a radial (or lateral) pocket 136 (or recess) in the inner part 13, which is inserted into the shaft tube 11. The recess 116 in the shaft tube 11 is preferably (only) slightly wider than the nose 161 of the driver 16, so that rotation of the driver 16 relative to the shaft tube 11 is prevented. The driver 16 can thus only execute an axial movement with respect to the shaft tube 11. The coupling between the driver 16 and the actuator element 15 via the annular groove 156 and the annular projection 165 is realized in such a way that the actuator element 16 can rotate relative to the driver 16.

[0062] The recess 116 in the shaft tube 11 and the driver 16 are arranged distally from the external thread 114 of the shaft tube 11. The axial movement of the driver 16 is thus transmitted through the nose 161 and the pocket 136 to the inner part 13, which accordingly also performs an axial movement. Thus, indirectly by introducing a rotational movement into the actuator element 15, the inner part can be axially displaced and thus the joint part 12 can be pivoted (or articulated) with respect to the shaft tube. Due to the self-locking nature of the threaded connection 114, 154, the angle of the joint part 12 cannot be reset by applying force to the joint part 12. The actuator element 15 therefore does not need to be rotationally secured to maintain the angular position of the joint part 12.

[0063] Fig. Finally, Figure 8 shows a schematic overall view of the instrument 1 including the distal articulation mechanism according to Fig. 1-4 and the proximal actuator mechanism according to Fig. 6 and Fig. 7. The intermediate middle section of the instrument 1, in particular the shaft tube 11 and the inner part 13, which is preferably approximately 4-6 times longer in the longitudinal direction than the combined length of the illustrated elements, has been removed for illustrative purposes. The functional unit (not shown) would be attached in the distal direction D, such as a jaw part or the like. List of reference symbols

[0064] Laparoscopic instrument 11 Shaft tube 12 Joint part 13 Inside 15 Actuator element 16 drivers 17 Retaining ring 111 Distal arms of the shaft tube 112 Opening 114 External thread of the shaft tube 116 Recess in the shaft tube 119 proximal end of the shaft tube 121 Proximal arms of the joint part 122 outer pins of the joint part 123 Through hole 131 slot-shaped longitudinal groove in the inner part 132 bulbous longitudinal groove in the inner part 133 distal end of the inner part 134 slot 135 pen 136 pocket in the interior 138 Middle section of the inner part 154 Internal thread of the actuator element 156 circumferential annular grooves of the actuator element 157 Gear structure 161 Nose of the driver 165 Ring projection of the driver A axis of rotation D Distal direction L Longitudinal axis P Proximal direction S level T dividing line

Claims

[1] Instrument (1) for minimally invasive surgery, preferably for laparoscopy, comprising: a shaft tube (11); a joint part (12) which is connected to the shaft tube (11) at a distal end of the shaft tube (11) in such a way that the joint part (12) is pivotable about an axis of rotation (A) with respect to the shaft tube (11); and an inner part (13) which is at least partially inserted into the shaft tube (11) such that the inner wall of the shaft tube (11) forms an axial sliding guide for the inner part (13) and can be driven exclusively axially within the shaft tube (11) via a proximal actuator mechanism (15, 16); wherein the inner part (13) is coupled at its distal end (133) to the joint part (12) in such a way that a driven axial movement of the inner part (13) causes the joint part (12) to pivot about the axis of rotation (A). [2] Instrument (1) according to claim 1, wherein the shaft tube (11) has an external thread (114) at a proximal end (119) into which an internal thread (154) of an actuator element (15) of the instrument (1) engages; wherein the actuator element (15) is coupled to a driver (16) of the instrument (1) in such a way that upon a rotational movement of the actuator element (15) about the shaft tube (11), the driver (16) moves axially, wherein the driver (16) has a nose (161) which is designed to engage through an opening (116) in the shaft tube (116) into a pocket (136) in the inner part (13) and to bring about an axial movement of the inner part (13) upon an axial movement of the driver (15). [3] Instrument (1) according to claim 2, wherein the actuator element (15) is formed on its outer side with a gear structure (157). [4] Instrument (1) according to claim 2 or 3, wherein the actuator element (15) is formed in several pieces and is arranged assembled around the shaft tube (11). [5] Instrument (1) according to one of claims 1 to 4, wherein the inner part (13) has at least one elongated hole (134) at its distal end (133) through which an axis coupled to the joint part (12) is guided, which axis is spaced from the axis of rotation (A) of the joint part (12) and arranged parallel to it. [6] Instrument (1) according to claim 5, wherein the axis coupled to the joint part (12) is formed by a transversely arranged cylindrical pin (135) which is passed through a respective circular through-bore (122) through a respective arm (121) of two proximal arms (121) of the joint part (12). [7] Instrument (1) according to one of claims 1 to 6, wherein the inner part (13) has at least in sections at least one recess extending along its longitudinal axis (L), in particular an outer longitudinal groove (131, 132). [8] Instrument (1) according to one of claims 1 to 7, wherein in the at least one recess, in particular outer longitudinal groove (131, 132), a force transmission element, in particular a tension band for actuating a jaw part of the instrument (1), and / or an electrical supply and / or signal line, and / or a blade is arranged. [9] Instrument (1) according to claim 8, wherein the corresponding recess, in particular longitudinal groove (131, 132), represents a guide for the tension band arranged in the at least one recess, in particular longitudinal groove, and / or the electrical supply and / or signal line arranged in the at least one recess, in particular longitudinal groove (131, 132), and / or the blade arranged in the at least one recess, in particular longitudinal groove (131, 132). [10] Instrument (1) according to one of claims 1 to 9, wherein the instrument (1) further comprises a functional unit at a distal end of the joint part (12) and a handling unit at the proximal end (119) of the shaft tube (11), wherein the functional unit can be actuated by means of the handling unit, wherein wherein the functional unit is in particular a cutting and / or sealing tool and / or a jaw part.

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