Elongated shaft instrument

Description

[0001] The present disclosure relates to an elongated shaft instrument, such as a minimally invasive medical instrument, an endoscope, or technoscope, on which a movable component and / or actuatable instrument head is located on the distal side. In particular, the disclosure relates to instruments in which the instrument head can be mechanically angled relative to the longitudinal direction in a controlled manner, in particular in a robot-controlled manner.

[0002] Minimally invasive medical instruments with a drivable and / or controllable instrument head at the distal end are already known. For example, DE 10 2015 215 469 A1 describes a medical-endoscopic instrument with which a forceps at the distal end is actuated via cables.

[0003] A robot-controlled endoscope is known, for example, from US Pat. No. 7,297,142 B2. There, an instrument head is also bent and actuated via a number of pull cables. However, robot control via pull cables is technically quite complex.

[0004] DE 10 2006 027385 A1 describes a solid-state actuator drive device with a piezoelectric drive. EP 1 098 429 A2 describes a similar electromechanical motor.

[0005] The elongated shaft instrument disclosed herein, in contrast, allows for precise control and / or actuation of a distal component or instrument head in a simpler manner. Furthermore, for example, the bending angle of a distal component or instrument head is not limited. If necessary, the instrument can be used for continuous rotation of a distal component or instrument head.

[0006] The shaft instrument according to the present disclosure has the advantage over the known drives that no cables are required to move and / or actuate a distal component or an instrument head at the distal end of the shaft.

[0007] According to a first aspect of the present disclosure, an elongated shaft instrument is provided with a drive system having two pulse generators that are oscillatory and move substantially parallel to one another in a longitudinal direction, a driven wheel that is rotatably mounted about a rotation axis for driving a movement and / or actuation of a distal component or instrument head of the shaft instrument, and a drive wheel that is movable to a limited extent in translation for force, form and / or frictional engagement with the driven wheel, wherein the drive wheel is drivable by the two pulse generators and is movable in oscillation in two oscillation directions.

[0008] An oscillatory movement of the pulse generator is particularly easy to implement in a robot- or computer-controlled system. The pulse generators can, for example, have oscillatory-excitable piezoelectric actuators at the distal shaft end and / or push / pull means as actuating elements, which can, for example, be excited into an oscillatory axial movement by piezoelectric actuators on the proximal side and transmit this oscillatory axial movement to the drive wheel. "Oscillatory movement" or "oscillation" here refers to a single or repeated back-and-forth movement of some kind, i.e., it can be a sinusoidal oscillation or pulsed, rectangular, sawtooth-shaped, continuous, discontinuous, periodic, or aperiodic. The output wheel can be formed by the radial outer surface of an output shaft, which is coupled to the distal component or instrument head for its movement and / or actuation.The distal component or the distal instrument head can be, for example, a scalpel that can be angled relative to a longitudinal direction of the shaft instrument, a pair of scissors, a forceps, a camera, a light, or any combination of these. Two or more drive systems of this type can be integrated into a shaft instrument, for example, to be able to drive multiple degrees of freedom of movement of the distal component or instrument head or a plurality of components independently of one another.

[0009] Optionally, the output gear can be continuously driven by the drive gear through a rolling force, form, and / or frictional engagement between a radial surface of the drive gear and a radial surface of the output gear. The rolling force, form, and / or frictional engagement between the radial surface of the drive gear and the radial surface of the output gear allows the oscillating movement of the pulse generator to be converted into a continuous rotation of the output gear. This enables a continuously variable, uniform rotation of the output gear, with the rotational speed being determined by the oscillation frequency of the pulse generator.

[0010] Optionally, the two oscillation directions can be essentially orthogonal to each other. This creates an oscillation plane in a simple and space-saving manner, which is preferably essentially orthogonal to the rotation axis.

[0011] In a preferred embodiment, the drive gear can be designed, for example, as a ring gear eccentrically engaging around the output gear. The radial surface of the drive gear can then be a radial inner surface, and the radial surface of the output gear can then be a radial outer surface. The radius of the inner surface of the drive gear is then larger than the radius of the radial outer surface of the output gear. The difference between the radius of the inner surface of the drive gear and the radius of the radial outer surface of the output gear can essentially correspond to an eccentric offset between the drive gear and the output gear. This provides sufficient freedom of movement for the rolling of a force, form, and / or frictional connection between the output gear and the drive gear.

[0012] In an alternative embodiment, not described in detail here, the output gear can be designed as a ring gear, with the drive gear engaging eccentrically with the output gear. The radial surface of the drive gear can then be a radial outer surface, and the radial surface of the output gear can be a radial inner surface. In this embodiment, the drive gear, which has limited translational and rotational movement, can be designed as a spur gear and engage laterally with the ring gear contour of the output gear to drive it from the inside.

[0013] Optionally, the drive gear and the driven gear can have corresponding toothings, whereby a rolling force, form, and / or frictional connection is achieved through a partial circumferential and circumferential engagement of the toothings. This is particularly advantageous for preventing slippage. Alternatively or additionally, the radial surface of the drive gear and the radial surface of the driven gear can have corresponding friction surfaces.

[0014] Optionally, the gearing can be cycloidal and have the same module, whereby the number of teeth on the output gear and the number of teeth on the drive gear determine a reduction ratio between the oscillation frequency of the encoders and the rotational frequency of the output gear. With corresponding friction surfaces, the radius of the radial surface of the output gear and the radius of the radial surface of the drive gear can determine the reduction ratio. With a high reduction ratio, many oscillations of the encoders are required for a complete rotation of the output gear, or one oscillation of the encoders only drives the output gear a short distance further. This may be desired to achieve very precise control of the movement and / or actuation of the distal component or instrument head. The oscillation frequency of the encoders can be set accordingly high to achieve rapid rotation of the output gear.For example, the output gear can have a tooth count of Z 1 = 50 and the input gear a tooth count of Z 2 = 51, resulting in a reduction ratio of Z 1 / (Z 2 -Z 1 ) of 50:1. This means that 50 encoder oscillations are required to rotate the output gear by 360°. With an encoder oscillation frequency of 10 Hz, an angular velocity of 72° per second can be achieved, for example.

[0015] Optionally, the tooth height of the gears can be smaller than an eccentric offset between the drive gear and the driven gear. This provides sufficient movement clearance for the rolling of a force, form, and / or frictional connection between the driven gear and the drive gear. However, for the most space-saving design possible, the tooth height of the gears can be only minimally smaller than an eccentric offset between the driven gear and the drive gear, for example, 50% to 99%, preferably 90% to 99%, of the eccentric offset.

[0016] Optionally, the pulse generators can be configured to oscillate the drive gear at a substantially 90° phase shift relative to each other, so that it follows a circular path essentially parallel to the axis, with the radius of the circular path essentially corresponding to an eccentric offset between the drive gear and the output gear. "Parallel to the axis" refers to a purely translational displacement, with essentially no superimposed rotational movement. "Essentially" in this context means that slight rotational tilting movements within a range of ±5° may occur. Preferably, however, the drive gear follows a circular path with an exact parallel displacement, i.e., without any superimposed rotational movement.

[0017] Optionally, the direction of rotation of the output gear can be determined by a phase shift between the pulse generators. The sign of the phase shift can be particularly important here. For example, a phase shift of +90° can drive a clockwise rotation of the output gear, and a phase shift of -90° can drive a counterclockwise rotation of the output gear. Accordingly, the movement or actuation direction of the distal component or instrument head can be controlled via the phase shift.

[0018] Optionally, the output gear can be designed to angle the distal component or instrument head relative to the longitudinal direction, with the rotation axis running essentially orthogonal to the longitudinal direction. Alternatively, the rotation axis can run parallel to the longitudinal direction, for example, and cause a rotational movement of the distal component or instrument head around the longitudinal direction.

[0019] The pulse generators each have an elongated, longitudinally extending actuating element. Such an actuating element can be, for example, a push / pull rod or a hydraulic fluid channel. This eliminates the need to position a piezoelectric actuator within the very limited space at the distal end of a shafted instrument. Instead, it can excite the actuating element to axial vibrations proximal to the shaft of the shafted instrument, which it then transmits to the drive wheel along the length of the shaft.

[0020] The drive wheel can be driven by a first of the two pulse generators to oscillate in a first of the oscillation directions. The drive wheel can be driven by a second of the two pulse generators to oscillate in a second of the oscillation directions. This is advantageous for controlling the pulse generators because they can be driven independently of each other.

[0021] Alternatively or additionally, the drive wheel can be oscillatory in a first of the oscillation directions if the total movement of the pulse generators is not zero, and oscillatory in a second of the oscillation directions if the pulse generators move relative to each other. In this case, the pulse generators can be mechanically coupled, which poses a greater challenge for the control system, but enables a simpler symmetrical design with fewer components.

[0022] Optionally, the pulse generators can each be mechanically coupled to the drive wheel on the distal side via a joint system, wherein the joint system redirects a substantially longitudinally oscillating movement of a first of the two pulse generators by a first angle into a first of the oscillation directions of the drive wheel. This first angle can be fixed by the joint system or depend on the relative position or direction of movement of the pulse generators.

[0023] Optionally, the joint system can transmit a substantially longitudinally oscillating movement of a second of the two pulse generators into a second of the oscillation directions of the drive wheel. The second of the oscillation directions can be fixed in the longitudinal direction by the joint system, so that no deflection by a second angle is required. Alternatively or additionally, however, the joint system can deflect a substantially longitudinally oscillating movement of a second of the two pulse generators by a second angle into a second of the oscillation directions of the drive wheel, wherein the sum of the first and second angles is substantially 90°. This second angle can also be fixed by the joint system or depend on the relative position or direction of movement of the pulse generators. Optionally, the joint system can set the first angle and the second angle to substantially 45°.

[0024] Optionally, the pulse generators can each be mechanically coupled to the drive wheel on the distal side via at least one lever, with each lever being connected to a movable bearing axis on the associated pulse generator and to a movable bearing axis on the drive wheel. With at least one lever per pulse generator, this results in at least two levers in total. The levers can be identical in design and arranged symmetrically with respect to a mirror plane spanned by the longitudinal direction and the rotational axis. Alternatively, the levers can be differently shaped and arranged non-symmetrically.

[0025] According to the invention, the pulse generators are mechanically coupled to each other via two coupling levers. The coupling levers can optionally be rotatably mounted on at least one bearing axis parallel to the rotation axis and stationary with respect to the shaft.

[0026] According to the invention, the two coupling levers are interlocked in such a way that the bearing axes are always arranged symmetrically to the longitudinal direction. This eliminates any superimposed rotational movement of the drive wheel, allowing it to be displaced exactly parallel.

[0027] Optionally, the drive wheel and a joint system coupling the pulse generator to the drive wheel can be designed symmetrically with respect to a mirror plane spanned by the longitudinal direction and the rotational axis. This reduces the variety of components and simplifies the production process.

[0028] Optionally, a joint system coupling the pulse generator to the drive wheel, in particular at least one coupling lever, can be rotatably mounted on at least one bearing axis parallel to the axis of rotation and fixed with respect to the shaft.

[0029] Optionally, a joint system coupling the pulse generator to the drive wheel, in particular two coupling levers, can be rotatably mounted on two bearing axes parallel to the axis of rotation and fixed relative to the shaft. The bearing axes are arranged symmetrically with respect to a mirror plane spanned by the longitudinal direction and the axis of rotation. Here, too, the symmetrical design reduces the complexity of the production process.

[0030] Optionally, the elongated shaft instrument, for example a minimally invasive medical instrument, an endoscope or technoscope, can have a shaft extending in a longitudinal direction and a movable and / or actuatable component or an instrument head located distally on the shaft, wherein the drive system is arranged proximally of the component or instrument head and the pulse generators are guided longitudinally through the shaft.

[0031] The disclosure is explained in more detail below with reference to exemplary embodiments illustrated in the drawings. They show: Fig. 1 a perspective view of a distal portion of an exemplary embodiment of the instrument disclosed herein, which is not part of the invention; Fig. 2a-d Principle illustrations of the operation of a drive for the instrument head of an exemplary embodiment of the instrument disclosed herein, which is not part of the invention; Fig. 3a-c Principle diagrams of the parallel displacement of the drive wheel and the phase shift of an exemplary embodiment of the instrument disclosed herein, which is not part of the invention; Fig. 5 a side view of the output gear, the drive gear, the pulse generators and the joint system of a first exemplary embodiment of the instrument disclosed herein, which is not part of the invention; Fig. 6 a side view of the output gear, the drive gear, the pulse generators and the joint system of a second exemplary embodiment of the instrument disclosed herein, which is not part of the invention; Fig. 7 two side views of the output gear, the drive gear, the pulse generators and the joint system of a third exemplary embodiment of the instrument disclosed herein; Fig. 8 two side views of the output gear, the drive gear, the pulse generators and the joint system of a fourth exemplary embodiment of the instrument disclosed herein, which is not part of the invention; Fig. 9 two side views of the driven gear, the drive gear, the pulse generators and the joint system of a fifth exemplary embodiment of the instrument disclosed herein, which is not part of the invention; and Fig. 10 two side views of the output gear, the drive gear, the pulse generators and the joint system of a sixth exemplary embodiment of the instrument disclosed herein, which is not part of the invention.

[0032] In Fig. 1 1 shows a shaft instrument 1 in the form of a minimally invasive medical instrument with a shaft 3 extending in a longitudinal direction L. At the distal end of the shaft 3 there is an instrument head 5 which can be angled relative to the longitudinal direction L and has a scalpel blade 6 at the distal end. The instrument head 5 is movable in that it can be angled about a pivot axis A running perpendicular to the longitudinal direction L by a drive system integrated into the shaft instrument 1. Extending through the interior of the shaft 3 are elongated actuating elements 7, 9 which function as components of oscillatory pulse generators of the drive system. The actuating elements 7, 9 are in the form of push / pull rods and are arranged diametrically opposite one another on lateral sides of the shaft 3 at a distance from the longitudinal axis L of the shaft 3.The actuating elements 7, 9 can oscillate in the axial direction along the longitudinal direction L and thus function as components of oscillatory pulse generators. The pivot axis A here coincides with a rotation axis B, about which an output gear 10 is rotatably mounted to drive the angling of the instrument head 5. The output gear 10 is fixedly coupled to the instrument head 5. A drive gear 11 is designed in the form of a ring gear and engages around the output gear 10 eccentrically with respect to the rotation axis B or the pivot axis A. The drive gear 11 has limited translational movement and is coupled to the actuating elements 7, 9 via a joint system 13 such that it can oscillate in two oscillation directions, wherein the oscillation directions lie in a plane perpendicular to the rotation axis B or the pivot axis A.The oscillations of the drive gear 11 in the two oscillation directions can thus be driven by the two actuating elements 7, 9. The output gear 10 can be continuously driven by the drive gear 11 through a rolling force, form, and / or frictional engagement between a radial inner surface of the drive gear 11 and a radial outer surface of the output gear.

[0033] In Fig. 2 the drive principle between the drive gear 11 and the driven gear 10 is shown. Fig. 2a shows how the drive gear 11 can oscillate in a first oscillation direction x and a second oscillation direction y. The drive gear 11 has a substantially cylindrical inner surface 17 with a diameter R i . The drive gear 11 eccentrically engages the driven gear 10, which has a substantially cylindrical outer surface 19 with a radius R a . The diameter R i of the inner surface of the drive gear 11 is greater than the diameter R a of the radial outer surface 19 of the driven gear 10. The driven gear 10 is fixed relative to the shaft 3 and rotatable about the rotation axis B and cannot oscillate in the x or y direction. The eccentric offset between the drive gear 11 and the driven gear 10 corresponds exactly to the difference R i - R a . This results in the Fig. 2a shown position on the left side there is partial circumferential contact and thus frictional engagement between the radial inner surface 17 of the drive gear 11 and the radial outer surface 19 of the output gear 10. If the drive gear 11 now oscillates in the two oscillation directions x and y with a relative phase difference of 90° to one another, it can follow a circular path 21 with a substantially parallel displacement. For example, the oscillation in the x-direction can be described by x(t) = (R i - R a )·sin(2πft) and the oscillation in the y-direction by y(t) = (R i - R a )·cos(2πft), where f is the oscillation frequency in Hz. The radius of the resulting circular path 21 corresponds substantially to the eccentric offset R i - R a . If the drive gear 11 follows this circular path 21, the partially circumferential frictional engagement rolls circumferentially at the oscillation frequency f on the radial outer surface 19 of the output gear 10. This transmits a torque to the output gear 10.Instead of a frictional engagement between essentially cylindrical surfaces, the inner surface 17 of the drive gear 11 and the radial outer surface 19 of the output gear 10 can have mutually corresponding toothings in order to additionally achieve a force or form fit by a partially circumferential and circumferential engagement of the toothings.

[0034] In Fig. 2b It is shown how the oscillation of the drive wheel 11 in the x- and y-direction is driven by the correspondingly oscillatory pulse generators 23, 25. Here, the pulse generators 23, 25 are arranged orthogonally to each other. Fig. 2c An alternative drive option is shown using two pulse generators arranged parallel to each other. The pulse generator 23 exerts pressure pulses in the negative x-direction on the drive wheel 11, which compresses a corresponding compression spring or elastomer element on the opposite side, which returns the drive wheel 11 in the positive x-direction. The pressure pulses of the pulse generator 25, also exerted in the positive x-direction, are deflected by 90° in the negative y-direction via a deflection pulley, so that the drive wheel 11 compresses an opposite compression spring or elastomer element in the negative y-direction, which returns the drive wheel 11 in the positive y-direction. Fig. 2d The design is more symmetrical. Here, during oscillations, the pulse generators 23 and 25 are each deflected by 45° via a respective deflection pulley. The resulting oscillation directions x and y are orthogonal to each other, but tilted by 45° relative to the previously described oscillation directions.

[0035] Fig. 3a und 3b show two basic possibilities to force the most exact parallel displacement of the drive wheel 11 along a circular path 21 and thus to avoid superimposed rotational movements of the drive wheel 11. Fig. 3a shows a plurality of eccentric bearings 15 (here three) that prevent or severely restrict a rotational movement of the drive wheel 11. In Fig. 3b A central eccentric bearing 15 is shown, which enforces the eccentricity of the drive wheel, but cannot prevent rotational overlap. The disadvantage of such a forced guide is that the force, form, and / or frictional connection between the drive wheel 11 and the driven wheel 10 is maintained at all times and cannot be separated. In the event of a fault, however, it is advantageous if the force, form, and / or frictional connection can be released to allow easy extension of the instrument head joint and removal of the instrument from the patient's body through a trocar. Fig. 3c The phase difference between the oscillations in the x- and y-direction is illustrated. The amplitude of the oscillation corresponds to the eccentric offset R i - R a . The oscillations are shown here as a function of the orbit angle φ(t)=2πf t, with which the partial circumferential force, form and / or frictional engagement rotates on the radial outer surface 19 of the output gear 10. The solid line represents the deflection in the x-direction with x φ = R i − R a ⋅ sin 2 π 360 ° φ and the dashed line represents the deflection in the y-direction with y ( φ ) = ( R i - R a ) · cos 2 π 360 ° φ In Fig. 3a a position of the drive wheel 11 at φ = 90° with x = R i - R a and y = 0 is shown. In Fig. 3b the drive wheel 11 is shown at φ = 270° with x = R a - R i and y = 0.

[0036] Figuren 4a bis 4c illustrate the problem of an inexact parallel displacement of the drive wheel 11 during the two-dimensional oscillation. In the Fig. 4a In the diagram shown, the angle of rotation of the output gear 10 is plotted as the ordinate against the number of revolutions of the drive gear 11. An exact parallel displacement without superimposed rotary movement of the drive gear 11 results in a straight line through the origin, the gradient of which is determined by the ratio of the eccentric offset R a - R i to the outer diameter R a of the output gear 10. In the example shown, the drive gear 11 and the output gear 10 are toothed with one another, with the number of teeth Z 1 of the output gear being 50 and the number of teeth Z 2 of the output gear being 51. As a result, the driven gear 10 is rotated by one tooth per revolution of the drive gear 11, or for a complete revolution of the driven gear 10 by 360°, 50 revolutions of the drive gear 11 are required. In the joint system 13 selected here with certain lever ratios and distances of joint axes, a rotary oscillating movement with an amplitude of approximately 1.2° results, which in Fig. 4a along the abscissa. This rotational movement of the drive wheel 11 affects the transmitted torque and is superimposed on the purely translational movement (parallel displacement) shown as a straight line through the origin. Fig. 4b is Fig. 4a for the first two revolutions of the drive gear 11. It is clear that this superimposed rotational movement has a considerable influence on the drive of the output gear 10. The resultant, shown in dashed lines, does not correspond to a continuous rotational movement, but rather to a step-like rotational movement. In principle, however, a rotational movement that is as uniform as possible and closest to a straight line through the origin is preferred. This can be achieved by appropriately dimensioning the joint system 13 with specific lever ratios and distances between joint axes. Fig. 4c For example, a number of teeth Z 1 =10 of the output gear 10 and a number of teeth Z 2 =22 of the drive gear 11 are selected, as well as an eccentric offset of 0.25 mm. Due to the smaller number of teeth and the larger difference in the number of teeth, only 10 orbital movements of the drive gear 11 and thus oscillation periods are required to realize a complete rotation of the output gear 10 by 360°. Due to the changed reduction ratio (Z 2 - Z 1 ) / Z 1, the gradient of the straight line through the origin is greater than in the example of the Fig. 4a and 4b Although the amplitude of the rotational tilting movement of the drive wheel 11 is greater here, the resultant (shown in dashed lines) is less stepped and closer to the optimal origin line. By appropriately dimensioning the joint system 13, a parallel displacement can be achieved in which any superimposed rotational movement can be neglected.

[0037] Fig. 5 and 6show two embodiments in which the joint system 13 is designed so that the superimposed rotational movement of the drive wheel 11 can be neglected. The embodiments of the Fig. 5 and 6 which are not part of the invention, differ in that in Fig. 5 Levers are coupled together via bearing joint axes, and in Fig. 6 deformable solid joints enable mobility between the levers.

[0038] In Fig. 5 an output gear 10 is shown which has a radial outer surface 17 with cycloidal toothing with 50 teeth. The output gear 10 is mounted in a fixed position about the axis of rotation B with respect to a shaft 3 (not shown here). The output gear 10 is surrounded by an eccentrically engaging drive gear 11 which has a radial inner surface 17 with corresponding cycloidal toothing with 51 teeth. The eccentric offset here essentially corresponds to the difference between the radius R a of the radial outer surface 19 of the output gear 10 and the radius R i of the radial inner surface 17 of the drive gear 11. The tooth height of the toothing is selected to be only slightly smaller than the eccentric offset R i - R a . The axis of rotation B, which is fixed with respect to the shaft 3, extends orthogonally to the longitudinal axis L of the shaft 3 and intersects it. The drive wheel 11 is mechanically coupled to two actuating elements 7, 9 via a joint system 13.The actuating elements 7, 9 are designed in the form of elongated push / pull rods and extend within the shaft 3 in its longitudinal direction L. The two actuating elements 7, 9 run symmetrically to the longitudinal axis L, laterally offset at a distance H from the longitudinal axis L and diametrically opposite with respect to the longitudinal axis L. The actuating elements 7, 9 are axially movable in the longitudinal direction and are each coupled by their distal end to the joint system 13 via movable bearing axes L1, L2. The joint system 13 is itself mounted via a bearing axis L3 that is stationary with respect to the shaft 3, runs parallel to the axis of rotation B and intersects the longitudinal axis L offset from the axis of rotation B. The joint system 13 is coupled to the drive wheel 11 via movable bearing axes L4, L5. The joint system 13 has a first lever 27 that connects the bearing axis L1 to the bearing axis L3.The joint system 13 also includes a first coupling lever 29 connecting the bearing axis L1 to the stationary bearing axis L3. The first lever 27 and the first coupling lever 29 extend orthogonally to each other as part of a one-piece upper section 31 of the joint system 13. The upper section 31 of the joint system 13 determines the relative position of the bearing axes L1, L3, and L4 such that they are arranged in an isosceles and right-angled triangle, with the distance between the axes L1 and L4 corresponding to the distance between the axes L1 and L3. The movement of the bearing axis L4 is therefore limited to a circular path around the fixed bearing axis L3. During an axial movement of the upper actuating element 7 and thus of the bearing axis L1 in the tangential direction around the bearing axis L3, the drive wheel 11 is moved in the x-direction via the bearing axis L4, wherein the x-direction forms a first angle α1=45° with the longitudinal axis L.Thus, when the actuating element 7 oscillates axially in the direction of the longitudinal axis L, the drive wheel 11 oscillates in the x-direction. The oscillation amplitude, which is on the order of magnitude of the eccentric offset R i - R a , is so small compared to the distance between the bearing axes L4 and L3 that the superimposed rotational movement of the drive wheel 11 is negligible. A lower section 33 of the joint system 13 for coupling the distal end of the lower actuating element 9 via the bearing axis L2 has a second lever 35 and a second coupling lever 37. The lower section 33 is not formed in one piece like the upper section 31, but in two pieces with an additional movable bearing axis L6 and a control lever 39. The second coupling lever 37 is arranged essentially symmetrically with respect to the longitudinal axis L to the first control lever 29 and connects the movable bearing axis L2 to the fixed bearing axis L3.The control lever 39 and the second coupling lever 37 span a triangle defined by the bearing axes L3, L2, and L6. The second lever 35 then connects the bearing axis L5 and the bearing axis L6 to each other, thus coupling the lower section 33 of the joint system 13 to the drive wheel 11. The axial movement of the lower actuating element 9 in the longitudinal direction L is thus transmitted to a movement of the bearing axis L5 in the y-direction, wherein the y-direction forms a second angle α2=45° with the longitudinal axis L. The oscillation directions of the drive wheel 11 in the x-direction and x-direction are therefore orthogonal to each other. If the actuating elements 7, 9 now oscillate 90° out of phase with each other, the drive wheel follows a circular path, essentially parallel to each other, wherein the radius of the circular path essentially corresponds to the eccentric offset R i - R a. During each oscillation period, the output gear 10 is rotated one tooth further around the fixed axis of rotation B.After 50 revolutions of the drive wheel 11 or oscillation periods of the actuating elements 7, 9, the output wheel 10 has completed exactly one complete revolution of 360°.

[0039] The solid joints in Fig. 6 essentially correspond to the bearing axes L1 to L6 from Fig. 5 , where the fixed bearing axis L3 consists of Fig. 5 is formed by two stationary flexural joints, so that the joint system 13 here has seven flexural joints. The flexural joints are formed here as thinned sections of a deformable material. The kinematics of the drive gear 11 and the driven gear 10 are essentially identical to that shown in Fig. 5 The embodiment shown in Fig. 5 and 6 illustrated embodiments ,which are not part of the invention, is that the movement of one actuating element 7, 9 is independent of the movement of the other actuating element 9, 7 and these can therefore be controlled very easily.

[0040] This is in the Fig. 7 The third embodiment of the invention shown is different. Here, the actuating elements 7, 9 are coupled to one another in such a way that the control of only one of the actuating elements 9, 7 independently of the other actuating element 9, 7 is not possible. The actuating elements 7, 9 must therefore both be controlled in a coordinated manner. However, the more complex control is accepted in order to achieve a symmetrical structure of the joint system 13 and thus a reduced variety of components. In addition, the reduction ratio in the Fig. 7 shown third embodiment is different. The output gear 10 here has a number of teeth Z 1 = 40. The drive gear 11, on the other hand, has a number of teeth Z 2 = 44, resulting in a reduction ratio of Z 1 / (Z 2 -Z 1 ) = 10. It therefore takes ten full revolutions of the drive gear 11 to rotate the output gear 10 by one full revolution. Accordingly, the radii R i and R a of the radial inner surface 17 of the drive gear 11 and the radial outer surface 19 of the output gear 10 are selected such that a reduction ratio R a / (R i -R a ) = 10 results, so that one revolution of the drive gear 11 rotates the output gear 10 by 36° or four teeth. The joint system 13 is designed here essentially symmetrically with respect to the longitudinal axis L, ie the upper section 31 of the joint system 13 is symmetrical and essentially identical in construction to the lower section 33 of the joint system 13.The joint system 13 here has two bearing axes L3' and L3" which are fixed with respect to the shaft 3 (not shown here). The fixed bearing axes L3' and L3'' are arranged symmetrically with respect to the longitudinal axis L. Analogous to the one shown in . Fig. 5 In the exemplary embodiment shown, bearing axes L1 and L2 form the coupling of the joint system 13 to the distal ends of the actuating elements 7, 9, and bearing axes L4 and L5 form the coupling to the drive wheel 11. The joint system 13 further has bearing axes L6' and L6", which each have the same distance from the longitudinal axis L as the bearing axes L4 and L5, respectively, so that a first lever 27 is formed between the bearing axis L4 and the bearing axis L6', which is aligned parallel to the longitudinal axis L. Similarly, a second lever 35 is arranged between the bearing axis L5 and the bearing axis L6", which also extends parallel to the longitudinal axis L. A first control lever 39' extends between the bearing axis L6' and the bearing axis L1, and a second control lever 39" extends between the bearing axis L6" and the bearing axis L2. The bearing axes L4, L6' and L1 are positioned in a triangle relative to one another.The first lever 27 and the first control lever 39' are at a fixed angle to each other. Similarly, the second lever 35 is at a fixed angle to the control lever 39". The joint system 13 has a slotted guide 41', 41" in both the upper section 31 and the lower section 33, which follows a circular segment. The upper slotted guide 41' follows a circular segment around the upper bearing axis L6', the radius of which corresponds to the distance of the axis L6' from the fixed bearing axis L3'. Analogously, the lower slotted guide 41" follows a circular segment around the lower bearing axis L6" with a radius that corresponds to the distance between the lower bearing axis L6" and the lower fixed bearing axis L3". Due to the slotted guides 41' and 41", the first lever 27 and the second lever 35 are essentially movable in the x-direction, so that the drive wheel moves in the x-direction when the actuating elements 7, 9 are moved in the same direction. In the lower figure of . Fig. 7 Coupling levers 29, 37 are more clearly visible, which extend from the fixed bearing axis L3' to the bearing axis L6' and from the fixed bearing axis L3" to the bearing axis L6". The coupling levers 29, 37 are interlocked in such a way that the bearing axes L6' and L6" are always arranged symmetrically to the longitudinal axis L. As a result, the bearing axes L4 and L5 are always in the same x-position. This prevents any superimposed rotational movement of the drive gear 11, so that the ring gear 11 is displaced exactly parallel. In order to move the drive gear 11 in the y-direction, the actuating elements 7, 9 must be moved relative to one another. Due to the slotted guides 41' and 41", the bearing axes L4 and L5 are rotated about the bearing axes L6' and L6", whereby the y-position of the drive gear 11 changes.For example, if the upper actuating element 7 moves in the negative x-direction and the lower actuating element 9 moves at the same speed in the positive x-direction, the drive wheel 11 moves in the negative y-direction, i.e., downwards, and does not move in the x-direction. Conversely, if the upper actuating element 7 moves in the positive x-direction and the lower actuating element 9 moves at the same speed in the negative x-direction, the drive wheel 11 moves upwards only in the positive y-direction, with a purely parallel displacement. In this case, only the relative movement of the actuating elements 7 and 9 to each other is important.This means that if both actuating elements 7, 9 move in the x-direction, but the upper actuating element 7 faster than the lower actuating element 9, the drive wheel 11 moves upwards both in the x-direction and in the positive y-direction, since the upper actuating element 7 moves to the right in the positive x-direction relative to the lower actuating element 9.

[0041] The phase diagram in Fig. 7 illustrates the movements of the ring gear in the x- and y-direction and the movements of the actuating elements 7, 9 in the x-direction with respect to the orbit angle of the ring gear in degrees. Fig. 7 is shown a rotation angle of the ring gear of 90°, where the y-position of the ring gear is 0 and the x-position is maximum, ie equal to the eccentric offset R a - R i . As can be seen from the diagram, the actuating elements 7,9 oscillate with a factor 1,25 larger amplitude in the x-direction. Furthermore, the oscillation of the actuating element 7 is phase-shifted to the left by a phase angle of arctan(0.5)=29.5° relative to the x-position of the ring gear. The lower actuating element 9 is correspondingly phase-shifted to the right by a phase angle of arctan(0.5)=29.5° relative to the x-position of the drive gear 11. The actuating elements 7, 9 are thus controlled precisely and in concert along the curves shown in order to achieve the corresponding, exactly parallel circular path of the drive gear 11 around the output gear 10.

[0042] In Fig. 8 A precisely parallel circular path of the drive gear 11 is also achieved. The joint system 13 comprises a double lever 43 and a lever 45, each of which is rotatable about the stationary axis of rotation B of the output gear 10. The double lever 43 is constructed symmetrically with respect to the axis of rotation B. The lever 45 has the same dimensions as one half of the double lever 43. Two toggle levers 47', 47" are connected to the double lever 43 and the lever 45, respectively, at the movable bearing axes L6' and L6", whereby the toggle levers 47', 47" are in turn connected to the actuating element 9 via the bearing axis L2. The actuating element 9 is displaceable in the x-direction and fixed in the other spatial directions. In the bearing axes L6" and L5, a coupling lever 29, 37 is connected to the double lever 43 and the lever 45, respectively, which have the upper bearing axes L1 and L4.In these bearing axes L1 and L4, the drive gear 11 is connected to the coupling levers 29, 37. In the bearing axis L1, the upper actuating element 7 also engages the ring gear 11. Due to the symmetrical design of the double lever 43, the coupling levers 29, 37 and the stationary position of the lower actuating element 9, the bearing axes L6" and L5 are always guided parallel, i.e. with the same y-position. Actuation of the actuating element 9 in the x-direction moves a simultaneous displacement of the bearing axes L5 and L6" in the y-direction via the toggle levers 47', 47". Since the coupling levers 29, 37 are identical, the bearing axes L1 and L4 also move simultaneously to one another in the y-direction. Since the coupling levers 29, 37 are rotatably mounted about the bearing axes L5 and L6", a movement of the ring gear 11 in the x-direction can be initiated via the actuating element 7. This parallel kinematics of the joint system 13 completely avoids any superimposition of a rotary movement.When the actuating elements 7, 9 are actuated, the drive gear 11 therefore moves purely translationally in the x- and / or y-direction. With a corresponding sinusoidal and phase-shifted linkage by both actuating elements 7, 9, the ring gear 11 can execute a precise circular path without superimposed rotation. However, the use of the toggle levers 47', 47" results in a non-linear relationship between the movement of the actuating element 9 in the x-direction and the y-displacement of the drive gear 11.

[0043] In Fig. 9 A further embodiment is shown which is not part of the invention. In this embodiment, the parallel displacement of the ring gear 11 is achieved by a movement coupling of the coupling levers 29, 37 and the connection of the drive gear 11 to the coupling levers 29, 37 via the levers 27, 35. The coupling lever 29 is rotatable about the stationary bearing axis L3' and the coupling lever 37 is correspondingly mounted about the stationary bearing axis L3". Both coupling levers 29, 37 are coupled to one another via toothed sections, with the transmission ratio here being 1:1. A bearing axis L6' is located on the coupling lever 29 and a corresponding bearing axis L6" is located on the coupling lever 39, with the axis distances from L6' to L3' and L6" to L3" being the same. As a result, the bearing axes L6' and L6" always move simultaneously on circular arcs, but essentially only in the x-direction.The lower actuating element 9 is rotatably mounted on the bearing axis L2 of the coupling lever 29, which is designed as a double lever, and the lever 27 is rotatably mounted on the bearing axis L6'. Similarly, the lever 35 is rotatably mounted on the coupling lever 37 via the bearing axis L6". The lever 27 has a further movable bearing axis L4, on which the ring gear 11 is rotatably mounted. The lever 35, which is also designed as a double lever, has the bearing axes L1, on which the upper actuating element 7 is mounted, and the bearing axis L5, on which the ring gear 11 is rotatably mounted. The axis distances from the bearing axis L6' to L4 and from L6" to L5 are the same. If a movement is initiated via the lower actuating element 9, the coupling lever 29 rotates about the axis L3'. Due to the toothing of the coupling levers 29, 37, the bearing axes L6' and L6" are always in the same x-position.If a movement is initiated via the upper actuating element 7, the lever 35 rotates about the axis L6". The bearing axis L5 moves in an arc around the bearing axis L6", but essentially in the y-direction. Due to the parallel kinematics described, the ring gear 11 can be moved purely translationally in the x- and / or y-direction. By initiating corresponding movements at the actuating elements 7, 9, the ring gear 11 can be moved purely translationally on a circular path around the axis of rotation B. The movements of the actuating elements 7, 9 are coupled here, however, as in . Fig. 7 .

[0044] In Fig. 10A further embodiment is shown which is not part of the invention. Here, the coupling levers 29, 37 are rotatably mounted on the stationary axes L3' and L3" and are coupled to one another by a toothing using corresponding toothed sections (not shown in detail). The coupling lever 29 has a further bearing axis L1, on which the lever 27 and the upper actuating element 7 can be rotated. The coupling lever 37 has a further bearing axis L6" on which a symmetrical double lever 35 is rotatably mounted. The ring gear 11 is rotatably mounted on the lever 27 and the double lever 35 via the bearing axes L4 and L5, respectively. A movement of the actuating element 7 causes a rotation of the coupling lever 29 about the stationary bearing axis L3' and, since the toothed sections engage with each other, also a rotation of the coupling lever 37 to the same extent in the opposite direction about L3".The bearing axes L6' and L6" are therefore always in the same x-position. Since the axis distances L1 to L4 and L6" to L5 are the same, the bearing axes L4 and L5 are also always in the same x-position. A movement of the upper actuating element 7 therefore initiates a translational movement of the drive wheel 11 in the x-direction. A movement of the lower actuating element 9 rotates a bell crank 49 which is mounted about the stationary axis L3‴. A connecting lever 51 is rotatably mounted on the bell crank 49 in the bearing axis L2' and on a further bearing axis L5' of the lever 35 and transmits the movement of the bearing axis L2' essentially in the y-direction to the symmetrical double lever 35, which then transmits this movement to the bearing axis L5 in the y-direction. A movement of the lower actuating element 9 therefore generates a translational movement of the drive wheel 11 in the y-direction.The advantage of this embodiment lies in the largely decoupled movements of the actuating elements 7 and 9 for the movement of the ring gear 11 in the x and y directions. With a correspondingly phase-shifted sinusoidal movement introduction into the actuating elements 7 and 9, the ring gear can be moved purely translationally on a circular path around the rotational axis B.

[0045] The numbered designations of the components or directions of movement, such as "first," "second," "third," etc., are chosen purely arbitrarily to distinguish the components or directions of movement from one another and can be changed at will. They do not imply any significance.

[0046] Equivalent embodiments of the parameters, components, or functions described herein that would appear obvious to a person skilled in the art in light of this description are included herein as if explicitly described. Features designated as optional, advantageous, preferred, desirable, or similar are to be understood as optional.

[0047] The described embodiments are to be understood as illustrative examples and do not represent an exhaustive list of possible embodiments.

Claims

1. An elongate shaft instrument (1) with a drive system comprising - two pulse generators (23, 25) oscillating substantially parallel to each other in a longitudinal direction (L), - an output wheel (10) rotatably mounted about an axis of rotation (B) for driving a movement and / or actuation of a distal component or instrument head (5) of the shaft instrument (1), and - a drive wheel (11) with limited translational movement for force-locking, form-fitting and / or integrally bonded connection to the output wheel (10), wherein the drive wheel (11) can be driven by the two pulse generators (23, 25) with two elongate actuation elements (7, 9) and is oscillatable in two oscillation directions (x, y), characterised in that the actuation elements (7, 9) are each mechanically coupled to the drive wheel (11) on the distal side via a joint system (13) with bearing axes (L1, L2), wherein the joint system (13) has two stationary bearing axes (L3', L3''), two movable bearing axes (L6', L6"), two control levers (39', 39"), two bearing axes (L4, L5) for coupling the joint system (13) to the drive wheel (11), two levers (27, 35) each oriented parallel to the longitudinal axis (L), which are each formed between one of the two bearing axes (L4, L5) and one of the movable bearing axes (L6', L6''), and wherein the levers (27, 35) are each at a fixed angle to one of the control levers (39', 39"), two coupling levers (29, 37) and two slot guides (41', 41"), wherein the respective slot guide (41', 41") follows a circular portion around the respective movable bearing axis (L6', L6''), the radius of which corresponds to the distance of the movable bearing axis (L6', L6'') from the fixed bearing axis (L3', L3''), so that the respective levers (27, 35) are each movable substantially in the longitudinal direction (L), and in that the bearing axes (L4, L5) are rotatable about the respective movable bearing axis (L6', L6") to couple the joint system to the drive wheel, and wherein the respective control lever (39', 39") extends from the respective bearing axis (L1, L2) to the respective movable bearing axis (L6', L6''), and wherein the respective coupling lever (29, 37) extends from the respective fixed bearing axis (L3', L3'') to the respective movable bearing axis (L6', L6''), wherein the two coupling levers (29, 37) are toothed with one another in such a way that the bearing axes (L6', L6") are always arranged symmetrically to the longitudinal direction (L).

2. The shaft instrument (1) according to claim 1, wherein the two directions of oscillation (x, y) are substantially orthogonal to each other.

3. The shaft instrument (1) according to claim 1 or 2, wherein the output wheel (10) can be continuously driven by the drive wheel (11) by means of a rolling force, force-locking, form-fitting and / or frictional connection between a radial surface (17) of the drive wheel (11) and a radial surface (19) of the output wheel (10).

4. The shaft instrument (1) according to any one of the preceding claims, wherein the drive wheel (11) is designed as a ring gear eccentrically engaging around the output wheel (10)5. The shaft instrument (1) according to claims 3 and 4, wherein the radial surface (17) of the drive wheel (11) is a radial inner surface (17) and the radial surface (19) of the output wheel (10) is a radial outer surface (19).

6. The shaft instrument (1) according to any one of claims 1 to 3, wherein the output wheel is designed as a ring gear, wherein the drive wheel engages eccentrically in the output wheel.

7. The shaft instrument (1) according to any one of the preceding claims, wherein the pulse generators (23, 25) are designed to drive the drive wheel (11) in an oscillatory manner substantially 90° out of phase with each other, so that it follows a circular path (21) substantially parallel displaced, wherein the radius of the circular path substantially corresponds to an eccentric offset between the output wheel (10) and the drive wheel (11).

8. The shaft instrument (1) according to any one of the preceding claims, wherein the direction of rotation of the output wheel (10) is determined by a phase shift between the pulse generators (23, 25).

9. The shaft instrument (1) according to any one of the preceding claims, wherein the drive wheel (11) is oscillatable in a first (x) of the oscillation directions (x, y) when the deflection of the pulse generators (23, 25) is not equal to zero in total, and wherein the drive wheel (11) is oscillatable in a second (y) of the oscillation directions (x, y) when the pulse generators (23, 25) move relative to each other.

10. The shaft instrument (1) according to any one of the preceding claims, wherein the joint system (13) transmits a movement of a first (23) of the two pulse generators (23, 25) oscillating substantially in the longitudinal direction (L) by a first angle (a1) into a first (x) of the oscillation directions (x, y) of the drive wheel (11).

11. The shaft instrument (1) according to claim 10, wherein the joint system (13) transmits a second (25) of the two pulse generators (23, 25) oscillating substantially in the longitudinal direction (L) into a second (y) of the oscillation directions (x, y) of the drive wheel (11).

12. The shaft instrument (1) according to claim 10 or 11, wherein the joint system (13) deflects a movement of a second (25) of the two pulse generators (23, 25) oscillating substantially in the longitudinal direction (L) by a second angle (a2) into a second (y) of the oscillation directions (x, y) of the drive wheel (11), wherein the sum of the first (a1) and second angle (a2) is substantially 90°.

13. The shaft instrument (1) according to claim 12, wherein the first angle (a1) and the second angle (a2) are substantially 45°.

14. The shaft instrument (1) according to any one of the preceding claims, wherein the coupling levers (29, 37) are each mounted rotatably on at least the stationary bearing axis (L3', L3'') parallel to the axis of rotation (B).

15. The shaft instrument (1) according to any one of the preceding claims, wherein the stationary bearing axes (L3', L3'') are arranged symmetrically with respect to a mirror plane spanned by the longitudinal direction (L) and the axis of rotation (B).