Surgical instrument and steering mechanism for it

Abstract

Wire-controlled steering mechanism (10) of a surgical instrument (1) having a shaft (2) with a longitudinal axis (B) along the longitudinal direction of which steering wires (12) run, wherein a tool tip (6) which can be angled by means of a distal angling mechanism (9) can be arranged at a distal end (5) of the shaft (2), wherein each guide wire (12) can be connected at one end to the angling mechanism (9) of the surgical instrument (1) and is guided at the other end by a guide device (22), wherein the steering mechanism (10) has an associated linear motor (14) for each steering wire (12), to which an end of the steering wire (12) pointing out of the guide device (22) is connected, characterized by the fact that the linear motors (14) are fixed in a retaining disk (16), wherein the retaining disk (16) has a central axial through-opening (18) in which a main shaft (21) extending coaxially from a proximal end (3) of the shaft (2) is mounted in a rotationally fixed manner, and has a receiving opening (19) for each linear motor (14), wherein the receiving openings (19) are equidistant from each other on a circular line.

Description

[0001] The invention relates to a surgical instrument and a steering mechanism for it.

[0002] Surgical instruments are known from the prior art that can be guided manually or by a robot and that feature tools whose tips can be pivoted by means of several interlocking swivel links. These swivel links are connected to a multitude of guide wires or cables to achieve precise control of the tool tip. Using many thin guide wires, as opposed to a few thicker ones, allows for a more uniform force distribution in all directions of angulation.

[0003] A generic surgical instrument is known, for example, from US 5,454,827 A, in which the distal pivoting elements are coupled via four steering wires to a proximally arranged spatially adjustable swashplate such that a movement of the spatially adjustable swashplate causes a corresponding relative movement of the distal pivoting elements and thus a pivoting of the tool tip, wherein the movement of the spatially adjustable swashplate is carried out manually via a type of joystick that is directly coupled to it.

[0004] The design of the drive for the steering wires with the spatially adjustable swashplate, on which all steering wires are mounted, has the advantage that this enables a spatially compact design and only one component needs to be moved to address all steering wires.

[0005] US patent 7,699,855 B2 discloses a surgical instrument that has an interface for connecting the instrument to a robotic arm. All drives that control the instrument are located within the robotic arm. The transmission of the rotational angles from the drives to the instrument is achieved via coupling discs in a common separating plane.

[0006] US 10 105 128 B2 also discloses a control of such a tool tip; there, this is done via a mechanism that includes toothed disc segments and connecting rods to transmit the movement of the drives to the swashplate.

[0007] The above designs are associated with a specific construction of a mechanical interface to the robot arm: In order to transfer the force to the tool, these mechanical force transmissions require gear ratios which, in order to keep any force loss as small as possible, are elaborately constructed by the components required to generate sufficient force transmission between the movement of the distal tool and the drives in the robot.

[0008] Furthermore, EP 3 508 160 A1 describes a flexible surgical instrument system comprising a flexible, continuous body structure made up of various structural segments, spacers and mounting discs, structural backbones, and a drive unit. The drive unit includes several linear motion mechanisms, each of which is rigidly connected at one end to a backbone and at the other end to two linearly movable output rods, each connected to a motor. A transmission chain between the motor and the output rods converts the rotary motion of the motor into a linear motion of the output rods. The motors are attached to a mounting plate that has a through-hole for the drive shaft of each motor.

[0009] DE 10 2014 205 036 A1 relates to an endoscopic instrument for connection to a surgical robot, comprising an instrument housing to which a shaft with at least one instrument part arranged distal to the shaft is attached. The instrument part and / or the shaft are movable relative to the instrument housing and are each operatively connected to control means, which can be coupled via a translationally movable coupling element to a linear drive unit that can be connected externally to the instrument housing. The linear drive unit can be formed by a fluidically actuated cylinder or a linear motor. An electric drive motor is preferably provided as the drive motor.

[0010] From US 2021 / 0 121 051 A1, a surgical instrument with a wire-controlled steering mechanism is known, in which steering wires run along the longitudinal axis in a shaft, at the distal end of which a tool tip, articulated by means of a distal angling mechanism, is arranged with a tool. Each steering wire is connected at one end to the angling mechanism and is guided at the other end by a guide device, wherein each steering wire is associated with a linear motor of an actuating unit, to which an end of the steering wire protruding from the guide device is connected.

[0011] Based on this state of the art, the object of the present invention is to provide an improved steering mechanism for a surgical instrument that has a simpler drive design with linear transmission characteristics and is also space-saving.

[0012] This problem is solved by a steering mechanism having the features of claim 1.

[0013] The further task of providing a surgical instrument whose tool tip is controlled by a structurally simple and space-saving steering mechanism is solved by the surgical instrument with the features of independent claim 7.

[0014] Further developments and preferred embodiments of the steering mechanism and the surgical instrument are described in the dependent claims.

[0015] A first embodiment of a wire-controlled steering mechanism for a surgical instrument according to the invention has a shaft with a longitudinal axis along which steering wires extend, wherein a tool tip that can be angled by means of a distal angling mechanism can be arranged at a distal end of the shaft. Each steering wire can be connected at one end to the angling mechanism of the surgical instrument. At the other end, each steering wire is guided by a guide device. The steering mechanism has a linear motor assigned to each steering wire, to which an end of the steering wire protruding from the guide device is connected. According to the invention, the linear motors are fixed in a retaining disc which has a centrally axial through-opening in which a main shaft extending coaxially from a proximal end of the shaft is mounted in a rotationally fixed manner.Furthermore, the mounting disc has a receiving opening for each linear motor, with the receiving openings equidistant from each other along a circular path. In the steering gear assembly, this forms a ring of linear motors that also holds the steering cables equidistant from each other. This allows for a compact and space-saving design.

[0016] In this context, "linear motor" refers to any motor that moves components in a straight line. A key advantage of linear motors is that no mechanical force transmission between the robot arm and the tool is necessary to control the movement of the tool's angling mechanism or other moving parts. The mechanical force is generated directly by the linear motors, with each guide wire being moved by its corresponding linear motor.

[0017] This creates a structurally simple steering mechanism that does not require any open, moving parts between the robot arm and the surgical instrument or the steering mechanism, and is therefore not only space-saving but also has improved cleaning properties.

[0018] A preferred embodiment of the steering mechanism according to the invention provides that the linear motors are linear magnetic cylinders. The linear magnetic cylinders can be connected via their electrical connection lines to an interface of the robot arm and further to control electronics, which control the linear motors individually or in combination, thus enabling precise, direct and linear movement of the steering wires.

[0019] Alternatively, the linear motor can be a pneumatic cylinder, whereby the tool can be connected to a corresponding compressed air connection on the surgical instrument or robot arm via a pre-defined compressed air port or connector. A compressed air control line can be provided for this purpose. This embodiment of the linear motor also allows for precise articulation of the angulation mechanism, as the movement is induced linearly and directly.

[0020] In a further embodiment of the steering mechanism according to the invention, each linear motor has a receiving device on its side facing the steering wire, in which the steering wire is received. Thus, each steering wire can be securely fastened, and the tension necessary for precise movement of the angling mechanism can be applied to the steering wire.

[0021] Furthermore, in yet another embodiment of the steering mechanism according to the invention, the receiving device is a clamping device. If a steering wire is damaged, for example, it can be easily replaced. Alternatively, the steering wires can also be screwed into the receiving device of each linear motor, or soldered, glued, or welded to it. The fastening method can be selected depending on the material properties of the steering wires.

[0022] In yet another embodiment of the steering mechanism according to the invention, the guide device is a fan-shaped disc that increases the radial distance of the steering wires from the longitudinal axis B of the shaft. By increasing the radial distance of the steering wires from the longitudinal axis of the shaft, for example from a diameter of 4 mm to a diameter of 18 mm, the stroke movements of the linear motors are minimized in order to achieve a pivoting angle of the tool tip corresponding to the degree of diameter increase.

[0023] In yet another embodiment of the steering mechanism according to the invention, the linear motors have electrical connection devices for connection to an electrical interface. These electrical connection devices can be simple electrical cables running parallel to the longitudinal axis of the tool, thus saving space. The electrical connection device can further comprise one or more connectors that make it possible to connect the steering mechanism within the surgical instrument to the electronics of the surgical instrument and ultimately to the electronics of the robot arm. Similarly, in the embodiment using pneumatic cylinders as linear motors, compressed air lines are provided for connection to a robot-side compressed air interface instead of electrical connection devices.

[0024] The invention further relates to a surgical instrument comprising a wire-controlled steering mechanism having a shaft with a longitudinal axis B, along the longitudinal direction of which steering wires run, wherein a tool tip with a tool, which can be angled by means of a distal angling mechanism, is arranged at a distal end of the shaft, and wherein an actuating unit for actuating the angular tool tip is arranged at a proximal end of the shaft, wherein the steering mechanism is a steering mechanism according to the invention.

[0025] The steering gear according to the invention allows for a simple and space-saving design of the surgical instrument, thus enabling easy connection to a robot arm, where the movement of the linear motors can be transmitted directly and linearly to the tool tip. The result is precisely controllable use of the surgical instrument.

[0026] In another embodiment of the surgical instrument, the distal angulation mechanism of the articulated tool tip consists of pivot links arranged at the distal end of the shaft, which are connected to the steering mechanism via guide wires running longitudinally along the shaft. An advantage of this design compared to known designs is that, despite the use of several guide wires—six, eight, or even more—a sensitive and reproducible adjustment of the distal pivot links is possible through the individually controlled motor actuation of each wire.

[0027] Further embodiments of the steering mechanism and the surgical instrument, as well as some of the advantages associated with these and other embodiments, will become clearer and more easily understood through the following detailed description with reference to the accompanying figures. Items or parts thereof that are essentially the same or similar may be designated with the same reference numerals. The figures are merely a schematic representation of one embodiment of the invention.

[0028] This shows: Fig. 1. A perspective view of the surgical instrument with a schematically represented actuating unit, Fig. 2 a perspective view of the steering mechanism according to the invention, Fig. 3 a side view of the steering mechanism according to the invention, Fig. 4 a first perspective detail view of the steering mechanism according to the invention, Fig. 5 a side-section detail view of the steering mechanism according to the invention and Fig. 6 another perspective detail view of the steering mechanism according to the invention.

[0029] In Fig. Figure 1 shows a surgical instrument 1 with a hollow shaft 2, which has a schematically depicted actuating unit 4 arranged at the proximal end 3 of the shaft 2 and a tool tip 6 arranged at the distal end 5 of the shaft 2. The tool tip 6 is connected to a tool 7, which can be actuated via an actuating element 8 mounted axially displaceably in the shaft 2 and which is in operative connection with the actuating unit 4 on its proximal side. The actuating unit 4 can be a manually operated handle or a component designed for robotic use, i.e., one that can be actuated without manual intervention.

[0030] For example, tool 7 of tool tip 6 can be a tool equipped with jaw parts, as in Fig. 1 shown, or it could be an endoscope, an applicator or the like.

[0031] The tool tip 6 is pivotable relative to the longitudinal axis 10 of the shaft 2 via a joint mechanism 9, wherein the joint mechanism 9 consists of pivot links 11 arranged at the distal end of the shaft 5, which are connected via guide wires 12 running in the longitudinal direction of the shaft 2 to a drive 13 arranged at the proximal end 3 of the shaft 2 such that a movement of the proximal-side drive 13 causes a corresponding relative movement of the distal-side pivot links 11 and thus a pivoting of the tool tip 6.

[0032] Although only the term steering wires is used above and below, steering cables can also be used functionally, which is why the term steering wires is to be understood synonymously as steering cables here.

[0033] The actuating element 8, which is axially displaceable in the shaft 2, for actuating the tool 7, which consists, for example, of two jaw parts, is designed as a pull / push rod in the illustrated embodiments.

[0034] The drive 13 for the steering wires 12 is designed as a motorized drive 13 in the surgical instrument 1 shown in the figures and described below.

[0035] The core component of the drive 13 is a wire-controlled steering mechanism 10 ( Fig. 2 to 6), on which the steering wires 12 are mounted in such a way that the steering wires 12 are moved by means of an electrical control and thus a pivoting of the tool tip 6 is effected, from whose tool in Fig. 2 and Fig. Figure 3 shows only the tool holder connected to the swivel links 11. The steering mechanism 10 makes it possible to precisely, sensitively, and reproducibly control the steering wires 12 for pivoting the distal swivel links 11 or the tool tip 6 in minute increments.

[0036] In Fig. 2 and Fig. Figure 3 shows that each guide wire 12 is connected at one end, i.e. distally, to the joint mechanism 9, or pivot links 11, respectively, and at the other end, i.e. proximally, as shown in Fig.As shown in Figures 2 to 6, the steering wires 12 are guided by a guide device 22, in this case a fan disc 22. The fan disc 22 serves to fan out the steering wires 12 and increase the circumference of the circle described by the steering wires 12 at the clamped location. Starting from the tool tip 6, the steering wires 12 are guided through the shaft 2 and through a rotatable main shaft 21 arranged coaxially to the shaft 21 at its proximal end 3. The main shaft 21 has axially extending slots 24 for this purpose, with the steering wires 12 exiting the shaft 2 being guided out through the slots 24 of the main shaft 21 and continuing in an axial-proximal direction being clamped by the fan disc 22. The fan disc 22 has wedge-shaped notches 23 arranged equidistantly around its circumference to ensure secure guidance of the steering wires 12.The guide wires 12 are drawn into the notch 23 by virtue of being under tension and guided there under tension by the tapered tip of the notch 23. To minimize its weight, the fan disc 22 has recesses that do not impair its stability; these are wedge-shaped through-holes 25.

[0037] In the proximal direction along the longitudinal axis B, a retaining disc 16 is arranged following the fan disc 22. A centrally axial through-opening 18 is provided in this retaining disc, in which the main shaft 21 is mounted to prevent rotation. The retaining disc 16 holds eight linear motors 14. For this purpose, the retaining disc 16 has a receiving opening 19 for each linear motor 14. All receiving openings 19 are equidistant from one another on an imaginary circle on the retaining disc 16. The circumference of this imaginary circle is smaller than the total circumference of the retaining disc 16 itself. In an alternative embodiment of the retaining disc, it can also simply have recesses into which the linear motors are clamped laterally.

[0038] The retaining disc 16 serves to hold and secure the linear motors 14. These linear motors 14 extend through the retaining disc 16; they have a terminal end to which electrical connection devices 17, here electrical leads 17, are located, and extend parallel to the longitudinal axis B of the surgical instrument 1 in a proximal direction.

[0039] The end of the linear motors 14 facing the fan disc 22 has receiving devices 15, which are designed here as clamping devices. A clamping screw 15a is inserted into a slot 15b of the cylindrically shaped receiving device 15. The steering wires 12 are connected to a movable end of the linear motor 14 by connecting them to the respective clamping device and are tensioned over the fan disc 22 with a predetermined tension.

[0040] The linear motors 14 can be linear magnetic cylinders with a connection device 17, which includes electrical leads 17. The linear motors 14 can be electronically controlled via these electrical leads 17. This electronic control is provided by electronics located within the surgical instrument 1 or by electronics located in a robot arm (not shown) that holds or operates the surgical instrument 1. When the linear motors 14 are controlled, they move and thus influence the control wires 12, which are pulled or loosened depending on the control (distal-proximal stroke of the linear motors), and act directly and linearly on the angulation mechanism 9 of the surgical instrument 1. Pneumatic cylinders can also serve as linear motors 14. REFERENCE MARK LIST 1 Surgical instrument 2 shaft 3 proximal end (shaft) 4 Actuating unit 5 distal end (shaft) 6 Tool tip 7 tools 8 Actuating element 9 Angle Mechanics 10 wire-controlled steering mechanism 11 Swivel link 12 Steering wire 13 Drive 14 Linear motor 15 recording devices 15a Clamping screw 15b slot 16 retaining disc 17 electrical connection device 18 Passage opening 19 Intake opening 21 Main wave 22 Fan disc 23rd notch 24 slots B Longitudinal axis of the instrument or shaft

Claims

[1] Wire-controlled steering mechanism (10) of a surgical instrument (1), which has a shaft (2) with a longitudinal axis (B), along the longitudinal direction of which steering wires (12) run, wherein a tool tip (6) which can be bent by means of a distal bending mechanism (9) can be arranged at a distal end (5) of the shaft (2), wherein each guide wire (12) is connectable at one end to the bending mechanism (9) of the surgical instrument (1) and is guided at the other end by a guide device (22), wherein the steering mechanism (10) has for each steering wire (12) a linear motor (14) associated therewith, to which an end of the steering wire (12) pointing out of the guide device (22) is connected, characterized by , that the linear motors (14) are fixed in a holder disc (16), wherein the holder disc (16) has a central axial passage opening (18) in which a main shaft (21) extending coaxially from a proximal end (3) of the shaft (2) is mounted in a rotationally fixed manner, and has a receiving opening (19) for each linear motor (14), wherein the receiving openings (19) are equidistant from one another on a circular line. [2] Steering mechanism (10) according to claim 1, characterized by that the linear motors (14) are linear magnetic cylinders or pneumatic cylinders. [3] Steering mechanism (10) according to claim 1 or 2, characterized by that each linear motor (14) has on its side facing the steering wire (12) a receiving device (15) in which the steering wire (12) is received. [4] Steering mechanism (10) according to claim 3, characterized by that the receiving device (15) is a clamping device. [5] Steering mechanism (10) according to one of claims 1 to 4, characterized by that the guide device (22) is a fan-shaped disc (22) which increases the radial distance of the steering wires (12) from the longitudinal axis (B) of the shaft (2). [6] Steering mechanism (10) according to at least one of claims 2 to 5, characterized by that the linear motors (14) have electrical connection devices (17) for connection to an electrical interface. [7] Surgical instrument (1) comprising a wire-controlled steering mechanism (10) having a shaft (2) with a longitudinal axis (B), along the longitudinal direction of which steering wires (12) run, wherein a tool tip (6) with a tool (7) is arranged at a distal end (5) of the shaft (2) and can be bent by means of a distal bending mechanism (9), and wherein an actuating unit (4) for actuating the bendable tool tip (6) is arranged at a proximal end (3) of the shaft (2). characterized by that the wire-controlled steering mechanism (10) is a steering mechanism (10) according to at least one of claims 1 to 6. [8] Surgical instrument (1) according to claim 7, characterized bythat the distal bending mechanism (9) of the bendable tool tip (6) consists of pivoting members (11) arranged at the distal end (5) of the shaft (2), which are connected to the steering mechanism (10) via the steering wires (12) running in the longitudinal direction (B) of the shaft (2).

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