SURGICAL MINIMALLY INVASIVE INSTRUMENT

Description

Technical field

[0001] The present disclosure relates to a medical instrument for minimally invasive surgery, in particular a laparoscopic instrument, with improved design, 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) design, with a proximal end / terminal section at which a user, usually a surgeon, handles the instrument, and a distal end / terminal section (also called the "application end") to which a functional unit (effector) is attached, for example, a sealing and / or cutting instrument. A small-diameter shaft typically runs between the proximal and distal ends, 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 used inside a patient, while the distal end of the instrument remains external for handling by the user. This type of surgery is minimally invasive in the sense that only the smallest possible opening of the patient's body is required.

[0004] Due to the instrument's elongated design, a challenge lies in reliably and precisely translating 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 form, low weight, and ease of handling are also highly valued.

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

[0006] Surgical instruments of minimally invasive design, as described above, are known from the prior art. They feature a proximal handle to which an instrument shaft (rigid or flexible) is attached. The instrument shaft and handle are often connected or connectable via a rotary coupling to allow the shaft to be rotated relative to the handle about its longitudinal axis. An instrument head is rotatably and / or tiltably mounted at the distal end of the shaft, and an effector is mounted, in particular, on this head.

[0007] Actuators (e.g., buttons, levers, handwheels, etc.) are provided on the handle, which is preferably designed as a handgrip, to operate the instrument head. 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 routed inside the instrument shaft, which is designed as a tube for this purpose. The gear train can be either a rotary or a push / pull rod, the movement of which is transformed into a pivoting and / or rotating motion of the instrument head. This requires a transformation mechanism, for example, in the form of force-redirecting elements or similar components in the distal part of the instrument head, which is generally mechanically complex and expensive. Since several parts must always interact in such a motion-transformation mechanism (in series, i.e., along the direction of the gear train), a chain of tolerances inevitably results, ultimately leading to vague and imprecise handling of the instrument for the operator. Increased susceptibility to malfunctions is also to be expected.

[0009] US 11,510,669 B2 discloses a handheld surgical instrument comprising a handle housing, an elongated shaft section configured to extend distally relative to the handle housing, and a surgical end effector configured to couple to a distal end of the shaft section. A hinged screw is functionally connected to the surgical end effector, and a hinged nut is arranged around and functionally connected to the hinged screw. The hinged screw is configured to displace in response to rotation of the hinged nut, thereby moving the surgical end effector between a parallel orientation relative to the shaft section and a non-parallel orientation relative to the shaft section.

[0010] US 5,330,502 A discloses an endoscopic instrument, such as a dissector, scissors, or grasper, in which a shaft is provided that defines a longitudinal axis of the instrument. The shaft can rotate around the handle portion of the instrument. This mechanism also allows the end effectors to articulate with respect to the longitudinal axis of the shaft. This articulation is achieved by angling the end effector relative to the shaft. A locking mechanism is also disclosed that allows the rotational aspect of the device to rotate the entire joint mechanism.

[0011] US 2017 0 071 618 A1 discloses a steerable laparoscopic instrument comprising a transmission part, a first disk, a second disk, a bending part, a third disk, a working part, a handle, and a housing. The first disk is connected to an outer tube such that the rotation of the first disk on a first axis along which the outer tube extends rotates the outer tube accordingly on the first axis. The second disk is coupled to an inner tube such that the rotation of the second disk on the first axis moves the inner tube accordingly along the first axis. The third disk is arranged at a first end of the transmission part. A central transmission rod extending along the first axis is coupled to the third disk.The central transmission rod is coupled to the third disk in such a way that the rotation of the third disk on the first axis drives the central transmission rod to rotate accordingly on the first axis.

[0012] US 2016 O 361 107 A1 discloses a surgical instrument with an elongated outer instrument shaft. A proximal end section of the outer shaft is surgically connected to a shaft knob mounted in the barrel section of a proximal handle assembly. The knob is positioned to cause axial rotation of the outer instrument shaft, together with an actuating shaft, about its longitudinal axis.

[0013] US 5,626,587 A discloses an endoscopic surgical stapling device with a tubular shaft that can be rotated about a longitudinal axis relative to a handle. The shaft rotation is effected at the handle by turning a knob attached to the handle that engages with the tubular shaft. Summary of Revelation

[0014] Therefore, the tasks and objectives of this disclosure are to address the aforementioned challenges arising from the prior art and to satisfy the aforementioned existing needs, and in particular to provide an improved articulatory instrument for minimally invasive surgery, preferably a laparoscopic instrument, which combines a small form factor and good handling with precise operability.

[0015] The problems of the present disclosure are solved by the features of claim 1.

[0016] Accordingly, the invention provides an instrument for minimally invasive surgery, preferably for laparoscopy, comprising: a shaft tube; a joint part which is articulated to the shaft tube at a distal end / end section in such a way that the joint part is pivotable (or: articulable) about an axis of rotation (extending perpendicular to the shaft tube axis) with respect to the shaft tube; a proximal actuator mechanism (15, 16); 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 the proximal actuator mechanism; wherein the inner part is coupled to the joint part at its distal end 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.

[0017] A key concept of this disclosure is that, through the clever design of an inner part (or "inlay") and a distal articulation mechanism as well as a proximal actuator mechanism, which interact with the inner part, both mechanical actuation of the instrument and structural stability are provided. Furthermore, both a reduction in the number of components and a simplification of the mechanics are achieved.

[0018] The terms "proximal" and "distal" always refer to the perspective of the user of the instrument, who handles the instrument on its proximal side so that a functional unit at its distal end can interact with the patient.

[0019] In this context, "axial" movement is understood to mean movement along a longitudinal axis, in particular 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.

[0020] Advantageous embodiments are claimed in the dependent claims and are explained in particular below.

[0021] The shaft tube preferably has an external thread at one proximal end (the thread preferably does not extend all the way to the proximal end of the shaft, but is positioned as close as possible to it), into which an internal thread of an actuator element engages. The actuator element can be coupled to a driver of the instrument such that, when the actuator element rotates around the shaft tube (or around the external thread of the shaft tube), the driver moves axially, and in particular, exclusively axially. An (inwardly directed) lug of the driver can be configured to engage a pocket (or recess) in the inner part through an opening in the shaft tube and, when the driver moves axially, cause an axial movement of the inner part. In this way, a space-saving rotational movement at the proximal end of the instrument can be converted into a desired axial movement of the inner part.According to the invention, this axial movement is in turn converted into a pivoting (or: articulation) of the joint part.

[0022] The coupling of the shaft tube, actuator element, drive, and inner part can particularly preferably be designed to be self-locking. This advantageously maintains the pivoted position of the joint until it is changed again by a further 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.

[0023] The actuator element can advantageously be designed with a gear structure (or as a gear) on its outer surface. In this way, user input can be captured or converted rotationally and transferred to the actuator element.

[0024] The actuator element (preferably designed with a gear structure) can be multi-part and assembled around the shaft tube. This multi-part design offers advantages in manufacturing, for example in injection molding, but also in assembly around the shaft tube, as the actuator element does not need to be threaded onto the shaft tube but can be placed around it in any assembly step. The multi-part actuator element can be held together in the instrument, for example, by a circumferential retaining ring and / or a part of the drive mechanism, such as an annular projection of the drive mechanism.

[0025] 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. This axis is spaced apart from and parallel to the axis of rotation of the joint part. Particularly preferably, the inner part has two (or more) mutually parallel and aligned elongated holes at its distal end through which the axis coupled to the joint part (which may, for example, be fixedly connected to the joint part) is guided. In this way, the pivoting movement is guided even more precisely and is therefore even more stable. Alternatively, instead of multiple elongated holes, a single elongated hole in the form of a through-hole with an oblong cross-section can also be used.

[0026] The axis (which is fixed to the joint part, for example) 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.

[0027] Preferably, the inner part has at least one recess, in particular a longitudinal groove, extending along its longitudinal axis, at least in some sections, in which a force transmission element (especially preferably a pull cord 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 several recesses, in particular longitudinal grooves, extending along the longitudinal axis, wherein at least one pull cord and / or at least one electrical supply and / or control line and / or at least one blade are arranged in one or more of them. Each recess, in particular a longitudinal groove, can preferably serve as a guide for the element arranged therein.

[0028] An electrical power supply can, for example, be set up to carry an alternating current signal (RF signal) to power an alternating current sealing tool, or a direct current to power and / or control an electric motor.

[0029] In this context, a longitudinal groove is understood to mean, in particular, an elongated recess on the outer surface of an elongated object, extending along (i.e., parallel to) the longitudinal axis of the elongated object (e.g., the elongated inner part), preferably over a large part of the elongated object's length (i.e., over 50% of the elongated length, over 75% of the elongated length, or even more). Unless otherwise immediately apparent, the term "longitudinal" in this disclosure always refers to a longitudinal axis extending from the proximal side to the distal side.

[0030] The inner part (or inlay) thus fulfills a dual function in the present invention: 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 longitudinal axis of the instrument).

[0031] Advantageously, the instrument also features a functional unit at a distal end of the jointed 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, and / or the like. List of characters

[0032] The present disclosure is explained in more detail below with reference to preferred embodiments and the accompanying figures. These show: Fig. 1 a schematic three-dimensional view of a section 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 another direction; Fig. 3 another schematic three-dimensional view of another detail of the section from Fig. 1 from yet another direction; Fig. 4 a schematic side view of the section from Fig. 1 with partial hiding of individual elements; Fig. 5 a schematic cross-sectional view through an inner part of the instrument made of Fig. 1-4 ; Fig. 6 a schematic longitudinal sectional view of a proximal section of the instrument from the Fig. 1-5 ; Fig. 7, 7a, 7b Schematic views of an actuator element in the form of a spindle nut with external teeth according to Fig. 6 ; Fig. 8, 8a a schematic overview longitudinal section and side view of the instrument made of Fig. 1-7 and Fig. 9 a side view of the (medical) instrument

[0033] The figures are schematic and are intended only to aid in understanding the present revelation. Identical elements are marked with the same reference symbols. Detailed description of preferred embodiments

[0034] Fig. 9 shows the basic structure of a minimally invasive surgical instrument according to the disclosure and in particular a so-called laparoscopic (electric) sealing and cutting instrument.

[0035] This instrument has a proximal handle with several integrated operating elements and / or actuators (e.g., operating levers for opening and closing a distal jaw, triggers for applying current to the jaw, etc.), to the distal end of which a tubular instrument shaft is mounted or can be mounted. The instrument shaft has a distal end to which an instrument head is hinged and can be angled / swiveled. The instrument head has an effector, in this case in the form of two scissor- / forceps-like (tissue) manipulation jaws, which are accordingly mounted / hinged to the instrument head. For example, the manipulation jaws can be coupled to each other in their respective central sections via a hinge pin, which is further secured or mounted in the instrument head.The distal sections of the intervention branches (distal to the hinge pin) are equipped with tissue intervention elements, such as electrodes or electrode areas, to seal (and / or cut) trapped tissue, and / or a cutting blade to sever tissue. The proximal sections of the intervention branches (proximal to the hinge pin) are equipped with or designed with pivot points, such as eyelets, forks, etc., to which a pull or push cable is attached. Finally, electrical leads are routed in / on the instrument head and connected to the electrodes or the electrical sections of the branches.

[0036] Both the pull / push cable and the electrical leads are routed proximally to the instrument handle within the instrument shaft and connected / coupled there to the corresponding actuating elements / actuators for optionally angling the instrument head, opening and closing the effector (in this case, jaw part) and actuating the electrode(s).

[0037] In this respect, the basic structure of the surgical instrument corresponds to the state of the art described at the beginning, although this structure, for example of the handle or the instrument head, may of course also be modified within the framework of the known state of the art.

[0038] Fig. 1 Figure 1 shows a schematic three-dimensional view of a distal end section of the surgical / medical instrument 1 according to an embodiment of the present disclosure, in which a joint is arranged.

[0039] According to a preferred embodiment of the present disclosure, this instrument 1 for minimally invasive surgery, preferably for laparoscopy, has in principle the following components: a shaft tube 11 which is coupled or can be coupled to a handle at its proximal end section; a joint / swivel element 12 forming or supporting an instrument effector, which is articulated to the shaft tube 11 at a distal end section such that the joint / swivel element 12 can pivot about an axis of rotation A perpendicular to the longitudinal axis L of the shaft tube with respect to the shaft tube 11; and an inner, rod-shaped actuating element / internal part 13 which is at least partially inserted into and supported in the shaft tube 11, for which the inner wall of the shaft tube 11 forms or has an axial sliding guide for the actuating element 13, wherein the actuating element 13 can be driven exclusively axially via a proximal gear / actuator mechanism 15, 16 on or in the handle;wherein the inner actuating part 13 is coupled at its distal end section 133 to the joint / swivel part 12 such that an axial movement of the inner actuating part 13, preferably manually induced / triggered / caused at the proximal gear / actuator mechanism 15, 16, causes a pivoting of the joint / swivel part 12 about the axis of rotation A; and wherein the shaft tube 11 has an external / spindle thread 114 at its proximal end section 119, which engages with a spindle nut 15, which is or forms an actuator element of the gear / actuator mechanism 15, 16 and which is coupled to the actuating part 13 as a further actuator element of the gear / actuator mechanism 15, 16 via a driver 16 that is relatively rotatable but axially fixed on the spindle nut 15.

[0040] Preferably, the spindle nut 15 is coupled to the actuating part 13 via the driver 16, such that during a rotational movement of the spindle nut 15 about the shaft tube 11, the driver 16 moves exclusively axially, wherein the driver 16 has a lug 161 which is configured to engage through a longitudinally slotted through-opening 116 in the shaft tube 116 into a pocket 136 on / in the inner actuating part 13, in order to effect exclusively an axial movement of the actuating part 13 within the shaft tube 11 during an axial movement of the driver 15 along the longitudinally slotted through-opening 116.

[0041] Preferably, the spindle nut 15 is designed on its outside with a gear structure 157, wherein the spindle nut 15 is preferably designed in multiple parts and is arranged in a composite form around the shaft tube 11.

[0042] Preferably, the inner actuating part 13 has at least one elongated hole 134 at its distal end section 133, oriented transversely to the longitudinal axis L of the shaft tube and elongated / widened in the radial direction of the shaft tube 12 or the inner actuating part 13, through which an axis / pin coupled to the joint / swivel part 12 is guided, which is spaced radially from the longitudinal axis L of the shaft tube and axially from the axis of rotation A of the joint part 12 and is aligned parallel to the axis of rotation A.

[0043] Preferably, the joint / swivel part 12 is longitudinally slotted at its end section facing the shaft tube 11, thereby forming two radially spaced, proximal longitudinal arms 121 and the axis coupled to the joint / swivel part 12 is formed by at least one transversely arranged cylindrical pin 135, which is passed through a radially oriented through-bore 122 in at least one of the two proximal arms 121 of the joint part 12.

[0044] Preferably, the inner actuating part 13 has at least one recess extending along its longitudinal axis L, in particular an outer longitudinal groove 131, 132, in which a force transmission element, in particular a pull cord for actuating a jaw part of the instrument 1, and / or an electrical supply and / or signal line, and / or a blade is arranged, preferably in the at least one recess, in particular an outer longitudinal groove 131, 132.

[0045] Preferably, the corresponding recess, in particular longitudinal groove 131, 132, provides a guide for the pull cord 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.

[0046] The instrument 1 more preferably also has 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 the functional unit is in particular a cutting and / or sealing tool and / or a jaw part.

[0047] The surgical / medical instrument 1, here exemplified as a laparoscopic instrument, specifically has an instrument shaft, in this case a shaft tube 11, which is articulated / hingedly coupled to an articulated part / instrument head 12. The articulated part / instrument head 12 is located at a distal end / end section (see distal direction D in Figure 1). Fig. 1 ) of the shaft tube 11, and the shaft tube 11 in turn at a proximal end / end section (see proximal direction P in Fig. 1 ) of the joint part 12.

[0048] The distal end (end section) of the shaft tube 11 terminates in (forms) two parallel arms 111 of the shaft tube 11, in each of which a circular opening 112 is arranged. In 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 spring-like and flexible, similar to a spring tongue, and radially expandable. Each of these arms 111 is provided with a through-hole oriented transversely to the shaft tube axis L, the axes of which A are aligned and which are designed to receive hinge pins (pins, tenons).

[0049] Fig. 2 Figure 1 shows the proximal end (end section) of the joint part / instrument head 12 in a further schematic three-dimensional view (perspective view). It can be seen that the proximal end (end section) of the joint part 12 also terminates in two parallel arms 121 of the joint part 12, each of which has a round outer pin 122 on its outer side. In In other words, the instrument head consists of a sleeve whose proximal end section is divided by an axial notch into two parallel-spaced arms, legs, or tabs 121, which are preferably spring-like and bendable, similar to a spring tongue. A radially outwardly projecting pin or bolt 122 is formed on each of these tabs 121, the mutually aligned central 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 is also aligned with each other and offset eccentrically 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.

[0050] 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 outwards over the arms 12 of the joint part 12 and the two outer pins 122 by being moderately and elastically bent apart. 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 lock into the openings 122 (spring-elastically), thus holding the joint part 12 in a 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 almost without play and only allows a rotation / pivoting movement of the joint part 112 about a rotation axis A (or: articulation axis), which is jointly defined by the outer pins / bolts 122.

[0051] 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 about an axis of rotation A which is arranged concentrically with the outer pins 122 and the circular openings 112.

[0052] In Fig. 2 It is also clearly visible that a circular through-hole 123 is formed through each of the two arms 121 of the joint part 12, with the two through-holes 123 being aligned with each other. Each circular through-hole 123 is spaced apart from the adjacent outer pin 122. The center of the circle of each through-hole 123 is closer to the proximal end of the joint part 12 than the center of the circle of the respective outer pin 122. Furthermore, each through-hole 123 is also offset relative to the respective outer pin 122 in a direction that is perpendicular to the axis of rotation A and perpendicular to a longitudinal axis of the joint part 12. Fig. 2 The through hole 123 is therefore offset downwards, in addition to being offset to the left, relative to the outer pin 122, for example.

[0053] In Fig. 1 It can again be seen that the instrument 1 also has an inner part (insert) 13 (or, in English, "inlay") that is formed separately from the shaft tube 11. This inner part 13 is arranged partly inside the shaft tube 11 and partly inside 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 As can also be seen, the space between the two arms 121 of the joint part 12 in longitudinal section can have a rounding, 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.

[0054] In other words, for the function of the instrument head itself (namely the nodding movement) as well as for the function of the effector (namely an opening and closing movement, especially a clamping movement, and the application of electric current), it is necessary that mechanical forces and electrical energy are reliably and precisely applied to the instrument head. Essentially, the only space available for routing the corresponding cables and power transmission lines is the cavity formed by the shaft tube.

[0055] For this reason, the present disclosure provides for the use of the inner part (inner actuating part) 13. This is essentially a preferably fully profiled pull / compression rod that is guided longitudinally displaceably in the shaft tube (the inner part rests at least partially against the inner wall of the shaft tube in a sliding manner) and which has a number of longitudinally extending external grooves that serve as guide grooves / channels for electrical conductors and cables. The inner part (inlay) in the form of a pull / compression rod is thus, in principle, a kind of guide for the conductors and force transmission cables to ensure reliable and precise actuation of the functions of the instrument head or its effector and simultaneously also has a quasi-smart function or additional function, namely, the inner part provides the force transmission cable for the actuation of the instrument head or its effector.whose nodding motion is itself guided by the shaft tube and therefore 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 to it in such a way that an axial displacement of the inner part relative to the tube shaft is transformed into a pivoting / tilting / nodding motion of the instrument head.

[0056] Fig. 3 schematically illustrates the distal end / end section 133 of the inner part 13 in detail. Fig. 3 It is therefore evident that the distal end / end section 133 of the inner part 13 is designed as a stepped section, i.e., 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 may, for example, comprise over 80% or over 90% of the total length of the inner part 13, advantageously has an outer circumference that 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 slidably through the shaft tube 11 in the radial direction.

[0057] In the distal end / end section 133 of the inner part 13, a through-hole is formed that extends transversely to the longitudinal axis L of the inner part 13. This through-hole is radially offset from the longitudinal axis L, forming an elongated slot that extends in a direction transverse to the longitudinal axis (preferably tangentially). The width of the elongated slot 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 chamfered and extends obliquely proximally from the distal end tip of the inner part in the region of the elongated slot.

[0058] Fig. 4 Figure 1 schematically shows – omitting the shaft tube 11 – the articulated connection between the joint part 12 and the inner part 13. A cylindrical pin 135, for example, is guided through the two through-holes 123 and through the at least one elongated hole 134 in the inner part 13, which is inserted into the sleeve-shaped joint part 12. Furthermore, the bolts 122 are engaged in the bores 112 of the shaft tube 11, as shown in the Fig. 1 shown. In construction 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, inclined obliquely proximally, runs between the hinge pin 135 and the bolts 122, as is also shown in the Fig. 1 As indicated, the leverage effect resulting from the radial distance between bolt 122 and hinge pin 135 allows the joint part 12, which is articulated to the shaft tube 11, to be pivoted (or: articulated) by a purely axial movement of the inner part 13 within the shaft tube 11. This is achieved by applying tension or pressure to the inner part 12 via the pin 135 and the at least one elongated hole 134, generating a torque on the joint part 13. For example, if the inner part 13 is moved axially in the proximal direction P with respect to the shaft tube 11, the pin 135 is moved through the elongated hole 134 (to the right). Fig. 4 The torque is pulled proximally and thus, due to the offset arrangement (or: due to the eccentric placement) of the through holes 123 and the axis of rotation A relative to each other, 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 tolerance-prone) joint / hinge is provided in the force transmission path 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 or the hinge pin 135.

[0059] Before discussing the preferred mechanisms for the axial actuation of the inner part 13 below, the advantageous embodiments of the inner part 13, in particular with regard to its cross-section, will be described.

[0060] As mentioned at the outset, functional units (effectors) are typically located at the distal end of the joint part 12, for the insertion and manipulation of which the instrument 1 is used. Such a functional unit can be, for example, a jaw, a cutting and / or sealing tool, and / or the like. The respective functional unit(s) are actuated proximally, from outside the patient's body, at the handle. This can be achieved 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.

[0061] On the other hand, a more direct, haptic-feedback actuation can also be provided. For this purpose, force transmission elements, such as pull cords / 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 activate a motor on the handle, which in turn actuates the force transmission element. Particularly with purely manual actuation, the user receives immediate feedback about the activity at the distal functional unit, for example, through the resistance felt. Especially in the latter case, it is essential that this feedback is as precise as possible and without any time delay to avoid a vague or imprecise feel.

[0062] Fig. 5 Figure 1 shows a schematic cross-sectional view through the inner part 13, specifically in its central section 138, i.e., between its proximal end and distal end 133. The overall cross-sectional area of ​​the inner part 13 is roughly circular, with various recesses / longitudinal grooves formed around the outer circumference of this circular shape. For example, the inner part 13 has two lateral, slot-shaped longitudinal grooves 131 on its outer surface, 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 convex longitudinal grooves 132. The slot-shaped longitudinal grooves 131 and the convex longitudinal grooves 132 are arranged such that a (in Fig. 5 perpendicular) axis of mirror symmetry or plane of mirror symmetry (along the longitudinal axis L of the inner part 13) can be drawn.

[0063] In the longitudinal grooves 131, 132, for example, a blade or an actuating string for axial displacement of a blade mounted in the instrument head, a force transmission element (e.g., a pull cord) preferably for actuating the effector (e.g., opening and closing the tissue-intercepting jaws), an electrical supply and / or signal line (e.g., for the electrodes on the jaws), and / or the like can be arranged. The inner part 13 thus also provides a guide for the accommodated elements (lines and force transmission strings), which is therefore implemented in a space-saving, simple, and cost-effective manner. For example, a pull cord can be arranged in each of the two slot-shaped longitudinal grooves 131 so that the pull cords can exert a symmetrical force on the jaw or its jaws. The bulbous longitudinal grooves 132 can, for example, be provided for electrical supply and / or control lines.This prevents the cables and wires from running haphazardly in the shaft tube 11 and thus avoids unnecessarily high frictional resistances that can cause actuation hysteresis.

[0064] Fig. 6 The schematic longitudinal sectional view illustrates the proximal actuation of the inner part 13 for its axial movement, and thus also the pivoting of the joint part 12 relative 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,

[0065] Preferably, the axial movement of the inner part 13 is effected in a space-saving manner by a rotary movement of a sleeve-shaped actuator element (spindle nut) 15 of the instrument 1.

[0066] For this purpose, the shaft tube 11 has an external thread (threaded spindle) 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 encompasses 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 fitted onto the shaft tube 11, for example in the form of a sleeve.

[0067] The actuator element 15 is preferably designed on its outer side as a gear (or: with a gear structure 157), as is particularly well illustrated in Fig. 7 This is evident. The actuator element 15 can alternatively be designed without gear structure 157 and then, for example, be designed for manual rotation.

[0068] Fig. 7 Figure 1 shows a schematic three-dimensional view of the actuator element 15, which is designed here, for example, as a gear in its outer contour. The gear teeth 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 effective 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.

[0069] As in Fig. 7 Furthermore, as can be seen, the actuator element 15 has a circumferential annular groove 156 in the longitudinal direction both before and after the gear structure 157.

[0070] The actuator element 15 is preferably designed in multiple parts, for example in two parts. Fig. 7 An example of a dividing line T between the two components of the actuator element 15 is shown, which is advantageously uneven, i.e., not within a plane, in order to make the actuator element 15 more robust against displacements and the like. Preferably, the dividing line T includes a step S for this purpose. The overall structure of the actuator element 15 can preferably be held together by circular structures arranged in the circumferential annular grooves 156, which facilitates simple assembly.

[0071] Alternatively, the actuator element 15 can also be formed in one piece. In this case, it can be slotted on one side. For assembly, it can be widened at the slot and pushed onto the shaft tube 11. If the external thread 114 is only attached to the shaft tube 11 in the form of a sleeve, the actuator element 15 can also be formed in one piece and without a slot.

[0072] In Fig. 6 The figure shows that a retaining ring 17 engages in 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.

[0073] The driver 16 is also arranged concentrically to and encompasses the shaft tube 11. 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. Thus, the driver 16 is not only mounted on the shaft tube 11, but also on 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 other elements) therefore form a proximal actuator mechanism.

[0074] The driver 16, in turn, has a radially inwardly projecting nose 161 which engages, through a radial (or lateral) longitudinally extending recess (slot) 116 in the shaft tube 11, in a radial (or lateral) pocket 136 (or recess) in the inner part 13, which is inserted into the shaft tube 11, in a form-fitting manner. 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 therefore only perform 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.

[0075] The recess 116 in the shaft tube 11 and the driver 16 are arranged distal to the external thread 114 of the shaft tube 11. The axial movement of the driver 16 is thus transmitted via the lug 161 and the pocket 136 to the inner part 13, which also undergoes an axial movement. Therefore, by indirectly introducing a rotational movement to the actuator element 15, the inner part can be axially displaced, and thus the joint part 12 can be pivoted (or articulated) relative to the shaft tube. Due to the self-locking nature of the threaded connection 114, 154, the return of the angle of the joint part 12 to its original position by applying force to the joint part 12 is prevented. The actuator element 15 therefore does not need to be rotationally secured to maintain the angular position of the joint part 12.

[0076] Fig. 8 Finally, a schematic overall view of instrument 1, including the distal articulation mechanics, is shown according to Fig. 1-4 as well as the proximal actuator mechanics according to Fig.6 und 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 elements shown combined, has been omitted for illustrative purposes. In the distal direction D, the functional unit (not shown), such as a jaw or the like, would be attached.

[0077] In summary, the disclosure provides an instrument 1 for minimally invasive surgery, preferably for laparoscopy, at least comprising: a shaft tube 11; a joint part 12, which is articulated to the shaft tube 11 at a distal end such that the joint part 12 is pivotable about an axis of rotation A with respect to the shaft tube 11; a proximal actuator mechanism (15, 16); and an inner part 13, which is partially inserted into the shaft tube 11 and is axially movable within the shaft tube 11 via the proximal actuator mechanism 15, 16; wherein the inner part 13 is coupled to the joint part 12 at its distal end 133 such that an axial movement of the inner part 13 causes the joint part 12 to pivot about the axis of rotation A. Bezugszeichenliste Laparoscopic instrument

[0078] 11 Shaft tube 12 Joint part 13 Inner part 15 Actuator element 16 Driver 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 External pins of the joint part 123 Through hole 131 Slotted longitudinal groove in the inner part 132 Bulbous longitudinal groove in the inner part 133 Distal end of the inner part 134 Slotted hole 135 Pin 136 Pocket in the inner part 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 Driver nose 165 Ring projection of the driver A Rotation axis DD Distal direction L Longitudinal axis P Proximal direction S Step T Separation line

Claims

1. An instrument (1) for minimally invasive surgery, preferably for laparoscopy, comprising: a shaft tube (11); a joint part (12) which is connected in an articulated manner to the shaft tube (11) at a distal end of the shaft tube (11) in such a manner that the joint part (12) is pivotable about an axis of rotation (A) with respect to the shaft tube (11); a proximal actuator mechanism (15, 16); and an inner part (13) which is inserted at least partially into the shaft tube (11) in such a manner 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 via the 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 manner that a driven axial movement of the inner part (13) causes pivoting of the joint part (12) about the axis of rotation (A); characterized in that the shaft tube (11) comprises, at a proximal end (119), an external thread (114) into which an internal thread (154) of an actuator element (15) of the actuator mechanism (15, 16) engages.

2. The instrument (1) according to claim 1, wherein the actuator element (15) is coupled to a driver (16) of the instrument (1) in such a manner that the driver (16) moves axially during a rotational movement of the actuator element (15) about the shaft tube (11), wherein the driver (16) comprises a nose (161) which is configured to engage into a pocket (136) in the inner part (13) through an opening (116) in the shaft tube (116) and to cause an axial movement of the inner part (13) during an axial movement of the driver (15).

3. The instrument (1) according to claim 1, wherein the actuator element (15) is formed on its outer side with a gearwheel structure (157).

4. The instrument (1) according to one of claims 1 to 3, wherein the actuator element (15) is formed in multiple pieces and is assembled around the shaft tube (11).

5. The instrument (1) according to one of claims 1 to 4, wherein the inner part (13) comprises, at its distal end (133), at least one elongated hole (134) through which an axis coupled to the joint part (12) is guided, wherein the axis is spaced apart from the axis of rotation (A) of the joint part (12) and is arranged parallel thereto.

6. The 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 guided through a respective circular through-hole (122) through a respective arm (121) of two proximal arms (121) of the joint part (12).

7. The instrument (1) according to one of claims 1 to 6, wherein the inner part (13) comprises, at least in sections, at least one recess, in particular an outer longitudinal groove (131, 132), running along its longitudinal axis (L).

8. The instrument (1) according to one of claims 1 to 7, wherein a force transmission element, in particular a pull band for an actuation of a jaw part of the instrument (1), and / or an electrical supply and / or signal line, and / or a blade is arranged in the at least one recess, in particular the outer longitudinal groove (131, 132).

9. The instrument (1) according to claim 8, wherein the corresponding recess, in particular longitudinal groove (131, 132), constitutes a guide for the pull 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. The instrument (1) according to one of claims 1 to 9, wherein the instrument (1) furthermore comprises a functional unit at a distal end of the joint part (12) and comprises a handling unit at the proximal end (119) of the shaft tube (11), wherein the functional unit can be actuated via the handling unit, wherein the functional unit is in particular a cutting and / or sealing tool and / or a jaw part.