Surgical or microsurgical instrument for a robotic teleoperation system

Abstract

Surgical instrument (1) for a robotic system (10) of surgical or microsurgical teleoperation comprising a transmission interface portion (2) having a frame (3) and at least one transmission element (4) which is movable with respect to the frame, an operating portion (5), at least one actuation tendon (6) between the transmission interface portion and the operating port ion for actuating the operating portion based on an actuation action (F) applied to the at least one transmission element (4); wherein the transmission interface portion (2) comprises at least one return pulley (7) for the at least one actuation tendon (6); said at least one return pulley (7) is mounted on the frame (3) of the transmission interface portion so that it can rotate about a rotation axis (X-X) and translate along a translation direction (Y -Y) with respect to the frame; - the rotation axis (X -X) of the at least one return pulley (7) is orthogonal to the translation direction (Y-Y) of the same return pulley (7).

Description

"SURGICAL OR MICROSU RGICAL INSTRUMENT FOR A ROBOTIC TELEOPERATION SYSTEM"DESCRIPTION

[0001] . Field of the invention

[0002] . The present invention relates to a surgical or microsurgical instrument.

[0003] . In particular, the surgical instrument according to the invention is suitable for a medical and / or surgical and / or microsurgical teleoperation system .

[0004] . Background art

[0005] . The known robotic systems for surgical teleoperation generally comprise a plurality of robotic manipulators comprising motors and respective actuation interfaces arranged to control a sterile surgical instrument lacking motorized elements.

[0006] . The surgical instrument typically comprises a distal articulated terminal which is actuated by actuation tendons. The actuation tendons are typically arranged between the transmission interface (also known as "backend") and the movable parts of the articulated terminal, so that the actuation action delivered by the motors of the robotic manipulator is transmitted to the articulated terminal by virtue of the activation of the actuation tendons of the surgical instrument itself .

[0007] . In some known solutions, the actuation tendons are wound around discoidal spools rotatably mounted on the transmission interface frame of the surgical instrument. The motors of the robotic manipulator rotate the discoidal spools, generating tension in the tendons wound thereon. Typically, each discoidal spool controls a single actuation tendon, whereby it is common practice to provide four pairs of discoidal spools in the backend of the surgical instrument, i.e. , at least four pairs of tendons having antagonistic effects, to move at least four degrees of freedom of the surgical instrument.

[0008] . In fact, in known surgical instruments, the followi ng degrees offreedom of the distal articulated terminal are typically controlled by antagonistic tendons: pitch , yaw, opening / closing i.e. , grip or cut, and roll. In particular, articulated terminals are known comprising an articulated "wrist" and two "jaws" which are individually movable about a yaw axis, thus defining a relative degree of freedom of opening / closing about the same yaw axis.

[0009] . In order to house the discoidal spools of the actuation tendons, some known transmission interfaces are provided with a plate facing proximally, i.e. , open to the robotic manipulator, thereby facing the discoidal spools of actuation to the respective motors of the manipulator. Since the torque applied by the motor depends on the radius thereof , it is usually desirable to maximize the diameter of the discoidal spools of the transmission interface of the surgical instrument for the engagement with rotary motors of corresponding diameter, thereby taking advantage of the arm with force equal to the radius.

[0010] . Also for these reasons, typical embodiments of surgical instruments for robotic teleoperation include rotation axes of the discoidal spools oriented transversely, i.e. , orthogonally with respect to the longitudinal extension axis of the shaft or rod of the surgical instrument. Therefore, a surgical instrument is made which is not symmetrical around the rod or shaft. However, this type of solution is not free from drawbacks and in particular the control of the degree of freedom of roll, i.e. , of rotation of the articulated terminal about the longitudinal axis of the positioning rod or shaft is affected by severe complications: in detail, surgical instruments of this type use a pair of antagonistic tendons to rotate the positioning shaft or rod with respect to the backend, introducing a degree of freedom of roll inside the surgical instrument. As actuation tendons are extended inside the positioning shaft, the solutions of the type described above necessarily require twisting the tendons inside the positioning shaft when the internal degree of freedom of roll is activated, i.e. , when the rod or shaft is rotated about the longitudinal axis thereof , it moves with respect to the proximal transmission interface (backend) where the spools to which the actuation tendons of the articulated terminal are wound are mounted at the distalopposite end of the rod itself.

[0011] . The drawbacks shown above make that type of surgical instrument unsuitable for an extreme miniaturization of the distal articulated terminal for microsurgical applications, such as microsurgical, micro-laparoscopy for example for neurosurgical applications.

[0012] . Surgical instruments actuated by means of a smaller number of tendons than the degrees of freedom they possess, for example four tendons to control six movements, have also been suggested, but this approach does not however solve the problem and equally imposes the involvement of the internal degree of freedom of roll which undesirably stresses the tendons of implementation.

[0013] . In addition, other examples of transmission interface between robotic manipulator and surgical instrument which do not require the presence of an internal degree of freedom of roll in the surgical instrument itself have been suggested. Such known examples typically include a backend extending about the longitudinal axis of the rod or shaft, substantially making a surgical instrument which is symmetrical or at least has a radial size balanced about the longitudinal axis of the rod or shaft.

[0014] . For example, the prior art document US-10786329 shows a robotic manipulator which has an annular extension, i.e. , it extends circumferentially around a central through channel in which the surgical instrument is inserted, i.e. , the rigid positioning shaft thereof. The surgical instrument has an enlarged backend portion which abuts against the annular manipulator when the positioning rod is inserted in the central through channel. In such a prior art solution, a plurality of motors are housed in the "doughnut" body around the central through channel, whic h engage respective transmission discs of the surgical instrument.

[0015] . Otherwise, transmission interface solutions for robotic surgery have been suggested, in which the transmission of the actuation torque delivered by the motors of the robotic manipulator occurs by converting it into a linear forward motion of a slider / piston.

[0016] . For example, the prior art document US-1 131 1348 shows a surgical instrument comprising in the backend thereof six transmissionpistons directed parallel to the direction of the positi oning rod and arranged radially equally spaced apart about the longitudinal axis of the rod which engage respective motors which advance linearly from the robotic manipulator. In this case, the degree of freedom of roll involves the surgical instrument in the entirety thereof together with the manipulator, i.e. , the manipulator rotates together with the surgical instrument about the axis of the positioning rod.

[0017] . The provision of the linear piston actuators allows keeping the friction low, which promotes miniaturization . For example, the prior art document WO-2023-047325 to the same Applicant suggests a surgical instrument with linear piston transmission particularly adapted to manage a miniaturized articulated terminal by virtue of the creation of a self stabilizing mechanism for advancing the pistons in the transmission interface portion of the surgical instrument.

[0018] . However, the radial arrangement of the transmission pistons as well as of the motors still imposes a certain radial size about the longitudinal axis of the positioning shaft or rod. A small radial size of the surgical instruments as well as of the robotic manipulators are highly desirable in microsurgical applications because they allow for a wide positioning freedom of two or more surgical instrume nts, where provided. The radial, i.e. , transverse, proximal size can be excessive in those microsurgical clinical applications which require access with at least two surgical instruments placed side by side and substantially parallel, so as to operate on the same working volume by accessing it from the same side such as, by way of illustration , the case in which both nostrils of a patient must be accessed simultaneously and with different instruments.

[0019] . From a mere design viewpoint, in order to deliver a certain torque, the motor components need a certain radial extension so as to create an advantageous torque arm and minimize the radial size of the motor components, which would mean simultaneously increasing the longitudinal dimension thereof to deliver greater force.

[0020] . Nevertheless, it must be considered that the longitudinal length of the positioning rod of the surgical instrument is also preferable to belimited, since the actuation tendons running inside the hollow body of the positioning rod or shaft are su bject to undesirable phenomena of recoverable and non-recoverable elongation which are accentuated with the length of the actuation tendon itself.

[0021] . The need is thus strongly felt to provide a solution for surgical or microsurgical teleoperation which promotes the extreme miniaturization of the operating components while simultaneously ensuring a very high versatility and adaptability to various operating configurations.

[0022] . Meanwhile, the need is felt to keep the size of the surgical and microsurgical instruments very small.

[0023] . Solution

[0024] . It is an object of the present invention to obviate the drawbacks complained of with reference to the prior art and suggest a solution to the needs mentioned above.

[0025] . This and other objects are achieved by a surgical instrume nt according to claim 1 .

[0026] . Some advantageous embodiments are the subject of the dependent claims.

[0027] . According to an aspect of the invention, a surgical instrument is provided, comprising a transmission interface portion having a frame and at least one transmission element which is movable with respect to the frame, an operating portion, and at least one actuation tendon for actuating the operating portion based on an actuation action applied to the at least one transmission element.

[0028] . The transmission interface portion comprises at least one return pulley for the at least one actuation tendon, said at least one return pulley is mounted on the frame of the transmission interface portion so that it can rotate about a rotation axis and translate along a translation d irection with respect to the frame, the rotation axis of the at least one return pulley is orthogonal to the translation direction of the same return pulley.

[0029] . In accordance with an embodiment, the at least one return pulley comprises a first return surface on which the at least one actuation tendon is wound and at least a second roll surface for rolling on arespective at least one translation guide element of the transmission interface portion of the surgical instrument.

[0030] . In accordance with an embodiment, th e first return surface and the at least a second roll surface of the at least one return pulley are both substantially circumferential surfaces with different radius. The radius of the first return surface for the actuation tendon is, according to an embodiment, greater than the radius of the at least a second roll surface for rolling on a respective at least one translation guide element.

[0031] . In accordance with an embodiment, the transmission interface portion comprises at least one guide element for guiding the translation of the at least one return pulley.

[0032] . The at least one guide element can comprise a guide rail made integral with the frame of the transmission interface portion and comprises one or more roll surfaces for the rolling of the at least a second roll surface of the return pulley. In accordance with an embodiment, the actuation tendon applies a force aimed at pushing the return pulley to the translation guide element; and in particular to the one or more roll surfaces of the guide rail.

[0033] . The at least one guide element can comprise one or more reference ropes fixed to the frame of the transmission interface portion and wound around the at least a second roll surface of the return pulley.

[0034] . The at least one guide element of the transmission interface portion can comprise recesses and reliefs and the at least a second roll surface of the return pulley can be a toothed wheel comprising corresponding recesses and reliefs, so as to form a movable rack-and- pinion coupling .

[0035] . In accordance with an embodiment, the at least one transmission element of the transmission interface portion comprises a rotative transmission element, for example a spool, adapted to rotate with respect to the frame of the transmission interface portion around which the actuation tendon is wound. For example, the rotative transmission element comprises a groove which is inclined, for example it is a helical groove, for receiving the actuation tendon during the translation of the at least onereturn pulley with respect to the frame of the tran smission interface.

[0036] . By virtue of the suggested solutions, the friction between the parts in the transmission interface portion of the surgical instrument is minimized.

[0037] . By virtue of the suggested solutions, an extreme miniaturization of the transmission interface of the surgical instrument is allowed.

[0038] . Brief description of the drawings

[0039] . Further features and advantages of the invention will become apparent from the following description of preferred embodiments, given by way of non-limiting indication, with reference to the accompanying drawings which are briefly described below. Note that references to “an” embodiment in this disclosure do not necessarily refer to the same embodiment and are to be understood as at least one. Moreover, for reasons of concisen ess and reduction of the total number of figures, a certain figure can be used to illustrate the features of more than one embodiment, and not all the elements in the figure can be necessary for a certain embodiment.

[0040] . Figure 1 -A is an axonometric view of a robotic system for surgical or microsurgical teleoperation , according to an embodiment.

[0041] . Figure 1 -B is an axonometric view showing a surgical instrument mounted on the motorized manipulator thereof , according to an embodiment.

[0042] . Figures 1 -C and 1 -D are axonometric views showing a surgical instrument, according to some embodiments.

[0043] . Figures 2-A and 2-B show a diagrammatic section view of a return pulley solution of the prior art.

[0044] . Figure 3 depicts an axonometric view of a return pulley, according to an embodiment.

[0045] . Figure 4-A shows an axonometric view of a portion of the frame of a surgical instrument mounting a plurality of return pulleys, according to an embodiment.

[0046] . Figure 4-B is a plan view obtained according to the viewpoint indicated by arrow B in Figure 4-A.

[0047] . Figure 4-C shows a section view of the portion of the frame in Figure 4-A mounted on an elongated positioning element of the surgical instrument.

[0048] . Figure 5-A shows a vertical elevation view of a return pulley of a surgical instrument, according to an embodiment.

[0049] . Figure 5-B shows a vertical elevation view of a return pulley of a surgical instrument, according to an embodiment, and of a rotative transmission element.

[0050] . Figure 6 is a section view of a transmission interface portion of a surgical instrument mounted on a motorized manipulator, according to an embodiment.

[0051] . Figure 7 shows a vertical elevation view of a return pulley of a surgical instrument, according to an embodiment.

[0052] . Figure 8 shows a vertical elevation view of a return pulley of a surgical instrument, according to an embodiment.

[0053] . Figure 9-A shows a vertical elevation view of a return pulley of a surgical instrument, according to an embodiment.

[0054] . Figure 9-B shows a vertical elevation view of a return pulley of a surgical instrument, according to an embodiment.

[0055] . Figures 1 0-A and 10-B are axonometric views of a transmission interface portion of a surgical instrument mounted on a motorized manipulator, according to an embodiment.

[0056] . Detailed description of some embodimentsReference throughout this description to "an embodiment" means that a particular feature, structure or function described in relation to the embodiment is included in at least one— embodiment of the present invention. Therefore, the formulation “in an embodiment” in various parts of this description do not necessarily all refer to the same embodiment. Moreover, particular features, structures or functions such as those shown in different drawings can be combined in any suitable manner in one or more embodiments.

[0057] . In accordance with a general embodiment, a surgical instrument 1 for robotic surgery or microsurgery is provided.

[0058] . The surgical instrument comprises a transmission interface portion 2 having a frame 3 and at least one transmission element 4 which is movable with respect to the frame and an operating portion 5 actuated by one or more actuation tendons 6.

[0059] . Preferably, the operating portion 5 comprises a plurality of rotational joints, for example pin joints (for example making an articulated cuff of the "pitch-yaw-grip" type) which are actuated by pairs of antagonistic actuation tendons, i.e. , having an antagonistic effect on a certain pin joint of the operating portion. The operating portion 5 is preferably arranged at the distal end of an elongated positioning element 8 of the surgical instrument 1 while the transmission interface portion 2 is arranged at the proximal end of the same elongated positioning element 8.

[0060] . The surgical instrument 1 further comprises at least one actuation tendon 6 between the transmission interface portio n 2 and the operating portion 5 for actuating the operating portion based on an actuation action F applied to the at least one transmission element 4.

[0061] . In accordance with an embodiment, as shown for example in Figure 1 -D, the at least one transmission element 4 is a rotative transmission element having a rotation axis J-J thereof and the actuation action F applied thereto is a rotative action (torque) which is aimed at winding / unwinding the actuation tendon 6 from the rotative transmission element 4.

[0062] . In accordance with another embodiment, as shown for example in Figure 1 -C, the at least one transmission element 4 is a linear transmission element which is adapted to move along a rectilinear trajectory, like a piston.

[0063] . Preferably, at least one preload spring 9 is provided, mounted between the frame 3 and the at least one transmission element 4 of the transmission interface 2 to keep the actuation tendon 6 taut. In particular, each transmission element 4 can comprise a respective preload spring 9 thereof. The provision of a preload spring 9 allows always applying a minimum elastic preload to the related transmission element 4, keeping the tendon taut even in the absence of any force applied to the transmissionelement 4 to ensure a rapid response of the actu ation tendon 6 itself . As shown for example in Figures 10-A and 10-B, a coil spring can preload the preload spring 9 and can be tensioned by rotating a connecting rod 29 fastened at one end thereof, and for example by rotating the connecting rod 29 by 90° about the rotation axis of the rotative transmission element 4 (spool) . In order to lock the connecting rod 29 in place and thus the preload spring 9 in a preloaded condition , a locking notch 28 can be provided, and the connecting rod 29 after being rotated by 90° is pushed into the locking notch 28 thereof.

[0064] . Advantageously, the transmission interface portion 2 comprises at least one return pulley 7 for the at least one actuation tendon 6. In particular, the at least one return pulley 7 is mounted on the frame 3 of the transmission interface portion 2 between a respective transmission element 4 and the operating portion 5.

[0065] . In accordance with a preferred embodiment, the at least one return pulley 7 is arranged so as to return the actuation tendon 6 towards the longitudinal cavity of the elongated positioning element 8, such as a shaft or a rigid rod. Preferably, each actuation tendon 6 is associated with a respective return pulley 7 and a respective transmission element 4.

[0066] . With further advantage, said at least one return pulley 7 is mounted on the frame 3 of the transmission interface portion 2 so that it can rotate about a rotation axis X-X and translate along a translation direction Y-Y with respect to the frame 3.

[0067] . The rotation axis X-X of the at least one return pulley 7 is orthogonal to the translation direction Y-Y of the same return pulley 7.

[0068] . In accordance with a preferred embodiment, when the transmission element 4 is activated, the respective return pulley 7 is rolled, i.e. , the return pulley 7 performs a rolling motion with respect to the frame 3 of the transmission interface portion 2.

[0069] . The provision of the rolling motion of the return pulley 7 allows minimizing , even eliminating, the frictions in play, without for this reason including ball bearings or other rolling members between the return pulley 7 and the frame 3.

[0070] . In particular, as shown for example in Figure 2-B, with respect to known solutions in which the return pulley 107 for the actuation tendon 106 was mounted on the frame 1 03 of the transmission interface portion 102 of the surgical instrument 101 by interposing a ball bearing , it is possible to reduce the number of components, thus favoring an extreme miniaturization of the transmission interface portion 2 itself and avoiding , at the same time, the risk of malfunctions of the rolling member components.

[0071] . The provision of a surgical i nstrument 1 with an extremely compact transmission interface portion 2 allows achieving unusual mounting configurations of the robotic system 1 0. In particular, a very small radial size of the transmission interface portion 2, i.e. , in a radial direction with respect to the extension direction of the elongated positioning element 8, allows arranging two or more surgical instruments 1 side by side and very close to each other and thus minimizing the angle between the elongated positioning elements 8 of said two or more surgical instruments 1 placed side by side.

[0072] . As mentioned above, the at least one transmission element 4 of the transmission interface portion 2 can comprise a rotative transmission element, adapted to rotate with respect to the frame 3 of the transmission interface portion 2 about a rotation axis J -J thereof. In this case, the robotic system 1 0 for surgical or microsurgical teleoperation preferably comprises at least one robotic manipulator 1 1 having the motorized actuators 12 thereof which are rotative actuators and which engage with the respective rotative transmission elements 4, or spools, of the surgical instrument 1 . The motorized actuators 12 of the robotic manipulator 1 1 are preferably operable under the control of a master control device (not shown) .

[0073] . A sterile barrier can be provided between the motorized actuators 1 2 of the motorized manipulator 1 1 and the respective transmission elements 4 of the surgical instrument 1 , for example a sterile drape provided with rigid reinforcements for transmitting the rotative actuation action.

[0074] . Therefore, when in operating conditions, a user of the roboticsystem 10, i.e. , a surgeon or a microsurgeon , activates the motorized actuators 1 2 of the robotic manipulator 1 1 by manipulating the respective master control device; the actuation action F is then transmitted, by the transmission elements 4, to the actuation tendons 6, and in particular by winding / unwinding the actuation tendon 6 on the spool 4 thereof , and thus to the operating portion 5 of the surgical instrument 1 .

[0075] . Therefore, when in operating conditions, the winding / unwinding of the actuation tendon 6 on the spool 4 thereof determines the translation of the return pulley 7, i.e. , the rolling thereof .

[0076] . In accordance with an embodiment, as shown for example in Figure 5-B, the rotative transmission element 4 comprises an inclined groove 17, for example a helical groove 1 7, for receiving the actuation tendon 6 during the translation of the at least one return pulley 7 with respect to the frame of the transmission interface. In this case, the rotation axis of the return pulley X-X is orthogonal to the rotation axis J-J of the spool 4 on which the actuation tendon 6 is wound.

[0077] . By virtue of such a configuration which provides for the translation of the pulley in the direction of the rotation axis J-J of the spool 4, it is also possible to wind the actuation tendon 6 on the spool 4 with a substantially constant radius, i.e. , to avoid repeatedly winding the actuation tendon on itself. A final actuation of the o perating portion of the instrument is thus allowed, and slippage, friction and a stop-and-go transmission of the motorized actuation action to the operating portion 5 are avoided.

[0078] . The robotic manipulator 1 1 can be arranged around the proximal segment of the elongated transmission element 8 of the surgical instrument 1 , as shown for example in Figure 6, i.e. , the robotic manipulator 1 1 can comprise a central through hole which receives the elongated positioning element 8 of the surgical instrument 1 . The frame 3 of the transmission interface portion 2 can thus comprise a mounting portion 21 having an insertion surface, e.g . , a frustoconical surface, which inserts and locks by mechanical interference in the central through hole of the robotic manipulator 1 1 . Therefore, the mounting portion 21 is preferably arranged around the elongated positioning element 8. The mounting portion21 can be made of polymeric material, for example PTFE or can be made by mirror sintering powders.

[0079] . In accordance with a preferred embodiment, the at least one return pulley 7 comprises a first return surface 31 on which the at least one actuation tendon 6 is wound and at least a second roll surface 32 for rolling on a respective at least one translation guide element 22 of the transmission interface portion 2 of the surgical instrument 1 . In particular, said first return surface 31 and said at least a second roll surface 32 are substantially circumferential surfaces of the return pulley 7, although they can comprise protrusions and / or grooves.

[0080] . As shown for example in Figure 3, the return pulley 7 can comprise a first circumferential return surface 31 and two circumferential roll surfaces 32 arranged axially opposite with respect to the first circumferential return surface 31 .

[0081] . In fact, the return pulley 7 defines an axial direction X-X coinciding with the rotation axis X-X of the pulley, a radial direction R-R orthogonal to the axial direction and incident thereto, and a circumferential direction C-C which is orthogonal to both the axial direction and the radial direction . In particular, the first circumferential winding surface 31 can comprise a circumferential groove which receives the actuation tendon 6.

[0082] . In accordance with an embodiment, said first circumferential winding surface 31 of the return pulley 7 and said at least one circumferential roll surface 32 of the same return pulley 7 have a different radius (or diameter) from each other.

[0083] . In particular, according to a preferred embodiment, the radius R1 of the first return surface 31 for the actuation tendon 6 is greater than the radius R2 of the at least a second roll surface 32 for rolling on a respective at least one translation guide element of the transmission interface portion 2. The provision of the return radius R1 greater than the winding radius R2 of the pulley 7 allows the actuation tendon 6 to be returned beyond the level defined by the rolling of the pulley itself .

[0084] . Preferably, as shown for example in Figures 4-A and 4-B, the frame 3 of the transmission interface portion mounts the return pulleys 7arranged radially with respect to the longitudinal extension direction of the elongated positioning element 8, i.e. , radially with respect to the surgical instrument 1 .

[0085] . The transmission interface portion 2 comprises at least one guide element 22 for guiding the translation, i.e. , the rolling , of the at least one return pulley 7. In particular, the at least one guide element 22 is arranged to allow the at least a second circumferential roll surface 32 of the return pulley 7 to roll. Where two separate second roll surfaces 32 are present on the same return pulley 7, two respective guide elements 22 can be provided in a corresponding manner.

[0086] . In accordance with a preferred embodiment, the at least one translation guide element 22 comprises a guide rail made integral with the frame 3 of the transmission interface portion 2. In particular, said guide rail comprises one or more roll surfaces 24 for rolling the at least a second roll surface 32 of the return pulley 7.

[0087] . Therefore, where applicable, a margin of the return pulley 7 can be inserted into the cavity 23 of the guide rail, thus exposing the radius R1 of the first return surface 31 while the second surfaces 32 roll on the respective facing roll surfaces 24 flanking the rail cavity 23.

[0088] . Said one or more roll surfaces 24 of the rail can be flat surfaces, for example directed parallel to the longitudinal extension axis of the elongated positioning element 8. Alternatively, said one or mo re roll surfaces 24 of the rail can be curved surfaces having concavity facing the rotation axis of the return pulley 7 or having concavity oppositely facing . The provision of a curved roll surface 24 of the frame 3 having concavity facing the rotation axis X-X of the return pulley 7, as shown for example in Figure 9-A, allows achieving a substantially stable equilibrium position towards which the return pulley 7 tends with respect to the frame 3, and therefore an equilibrium position of the respective rotational joint of the operating portion 5 of the surgical instrument 1 . The provision of a curved roll surface 24 of the frame 3 having a concavity facing away from the rotation axis X-X of the return pulley 7, as shown for example in Figure 9- B, allows achieving an unstable equilibrium position and thus favoring arapid actuation of the operating portion 5.

[0089] . The actuation tendon 6, when in operating conditions, applies a force aimed at pushing the return pulley 7 to the guide element 22, and in particular to the one or more roll surfaces 24 of the guide rail. In other words, the tension of the actuation tendon 6 as well as the winding angle thereof to the first return surface 31 of the return pulley 7 are chosen so that the pulley 7 is pushed against the roll surface 24. The tension on the actuation tendon 6 is provided by the preload spring 9 and / or by the inherent elasticity of the tendon itself .

[0090] . The actuation tendon 6 is preferably wound a plurality of times around the first circumferential return surface 31 of the return pulley 7, i.e. , it makes at least one complete winding (360°) around said first return surface 31 .

[0091] . The actuation tendon 6 is preferably a polymeric tendon formed by a plurality of braided fibers made of polymeric material, for example high molecular weight polyethylene (UHMWPE) .

[0092] . In accordance with an embodiment, the guide element 22 comprises one or more ropes 25 fastened to the frame 3 of the transmission interface portion 3 and wound around the at least a second roll surface 32 of the return pulley 7. It is thus possible to make a return pulley suspended from the frame by means of said one or more ropes 25. I n other words, according to this embodiment, the portion of the return pulley 7 comprising said two axially opposite second roll surfaces 32 acts as a rolling hub for the two ropes 25. Preferably, two reference ropes 25 and two second roll surfaces 32 of the return pulley 7 are provided, where each rope 25 is wound a plurality of times around a respective second roll surface 32 of the pulley. As shown for example in Figure 7, the one or more ropes 25 can be fastened to the frame 3 at both ends. Alternatively, as shown for example in Figure 8, the one or more ropes 25 can be fastened to the frame 3 at only one end, like a yo-yo, while the other end of the rope 25 can be fastened to the return pulley 7.

[0093] . In accordance with another embodiment not shown in the figures, the at least one translation guide element 22 of the transmissioninterface portion 2 comprises recesses and reliefs, and the at least a second roll surface 32 of the return pulley 7 is a toothed wheel comprising corresponding reliefs and recesses, so as to form a rack-and-pinion coupling .

[0094] . In accordance with a general embodiment, a robotic system 10 for surgical or microsurgical teleoperation is provided, comprising at least one surgical instrument 1 according to any of the previously described embodiments.

[0095] . Preferably, there are provided at least two surgical instruments 1 placed side by side.

[0096] . As mentioned above, the robotic system 10 further comprises at least one motorized manipulator 1 1 having an actuation interface thereof which engages with the transmission interface 2 of the surgical instrument.

[0097] . The at least one surgical instrument 1 is preferably a sterilizable and / or disposable component, thus lacking motors, which is mounted on the respective motorized manipulator 1 1 of the robotic system 10.

[0098] . The motorized manipulator 1 1 is preferably a manipulator comprising a plurality of motorized rotary actuators 12 for rotating the respective spools 4, i.e. , the rotative transmission elements 4 of the surgical instrument 1 . Ball bearings 15 or other rolling members 15 can be provided around each motorized actuator 1 2 of said plurality. The motorized actuators are in turn operatively connected to motors (not shown) which can be housed in the motorized manipulator 1 1 itself

[0099] . The mounting of the surgical instrument 1 to the respective motorized manipulator 1 1 can occur in various manners. In accordance with an embodiment, the motorized manipulator 1 1 can be arranged at the rear of the transmission interface portion 2 of the instrument 1 , i.e. , arranged on the side of the transmission interface 2 which is opposite to the elongated positioning element 8. In accordance with another embodiment, the motorized manipulator 1 1 can be arranged on the side of the transmission interface portion 2 of the instrument 1 from which the elongated positioning element 8 extends; therefore, in this embodiment, themanipulator comprises a through hole for receiving the proximal segment of the elongated positioning element 8.

[0100] . By virtue of the features described above, provided in mutual combination or not in particular embodiments, it is possible to meet to the aforementioned needs, thus achieving the aforementioned advantages, and in particular:

[0101] . - an extreme miniaturization of the transmission interface portion of the surgical instrument and a reduction in the number of its components is allowed;

[0102] . - the transmission efficiency of the actuation action can be maximized;

[0103] . - the at least one return pulley 7 on which the actuation tendon6 is wound rolls during the actuation of said tendon ;

[0104] . - the radius on which the pulley rolls is less than the radius on which the tendon is wound;

[0105] . - the winding angle of the actuation tendon on the return pulley and the load applied on the tendon itself generate a direct force towards the guide element 22 of the frame;

[0106] . - it is therefore possible to arrange two or more surgical instruments 1 side by side and substantially parallel to each other, i.e. , with a minimum angle between the respective rigid elongated positioning elements;

[0107] . - therefore, the robotic system 1 0 is suitable for applications in neuro-microsurgery where access to the microsurgical workspace can be made through the patient's nostrils;

[0108] . It is well understood that the combinations of features disclosed in the appended claims form an integral part of the present disclosure.

[0109] . In order to meet specific, contingent needs, those skilled in the art may make several changes and adaptations to the above-described embodiments and can replace elements with others which are fun ctionally equivalent, without departing from the scope of the appended claims.LIST OF REFERENCE SIGNS

Claims

CLAIMS1 . A surgical instrument (1 ) for a robotic system ( 10) of surgical or microsurgical teleoperation comprising :- a transmission interface portion (2) having a frame (3) and at least one transmission element (4) which is movable with respect to the frame,- an operating portion (5),- at least one actuation tendon (6) between the transmission interface portion and the operating portion to actuate the operating portion based on the actuation action (F) applied to the at least one transmission element (4) ; wherein :- the transmission interface portion (2) comprises at least one return pulley (7) for the at least one actuation tendon (6) ;- said at least one return pulley (7) is mounted on the frame (3) of the transmission interface portion so that it can rotate about a rotation axis (X - X) and translate along a translation direction (Y-Y) with respect to the frame;- the rotation axis (X-X) of the at least one return pulley (7) is orthogonal to the translation direction (Y-Y) of the same return pulley (7) .

2. The surgical instrument according to claim 1 , wherein :- the at least one return pulley (7) comprises a first return surface (31 ) on which the at least one actuation tendon (6) is wound ;- the same return pulley (7) further comprises a second roll surface (32) for rolling on a respective at least one translation guide element (22) of the transmission interface portion (2) of the surgical instrument.

3. The surgical instrument according to claim 2, wherein the first return surface (31 ) and the at least a second roll surface (32) of the at least one return pulley (7) are both substantially circumferential surfaces wit h different radius.

4. The surgical instrument according to claim 3, wherein the radius of the first return surface (31 ) for the actuation tendon is greater than the radius of the at least a second return surface (32) for rolling on a respective at least one translation guide element.

5. The surgical instrument according to any one of the preceding claims, wherein the transmission interface portion (2) comprises at least one guide element (22) for guiding the translation of the at least one return pulley (7).

6. A surgical instrument according to claim 5, wherein the at least one guide element (22) comprises a guide rail made integral with the frame (3) of the transmission interface portion.

7. The surgical instrument according to claim 6, wherein said g uide rail comprises one or more roll surfaces (24) for the rolling of the at least a second roll surface (32) of the return pulley (7).

8. The surgical instrument according to any one of claims 5 to 7, wherein the actuation tendon (6) applies a force aimed at pushing the return pulley (7) to the translation guide element; and in particular to the one or more roll surfaces (24) of the guide rail.

9. The surgical instrument according to claim 5, wherein the at least one guide element comprises one or more reference ropes (25) fixed to the frame (3) of the transmission interface portion (2) and wound around the at least a second roll surface (32) of the return pulley (7).

10. The surgical instrument according to claim 5, wherein the at least one guide element of the transmission interface portion (2) comprises recesses and reliefs; and wherein the at least a second roll surface (32) of the return pulley (7) is a toothed wheel comprising corresponding recesses and reliefs, so as to form a movable rack-and-pinion coupling .1 1 . The surgical instrument according to any one of the preceding claims, wherein the at least one transmission element (4) of the transmission interface portion (2) comprises a rotative transmission element, such as a spool, adapted to rotate with respect to the frame (3) of the transmission interface portion (2) around which the actuation tendon (6) is wound.

12. The surgical instrument according to claim 1 1 , wherein the rotative transmission element comprises a groove (1 7) which is inclined, for example is a helicoidal groove, to receive the actuation tendon during the translation of the at least one return pulley (7) with respect to the frame (3) of the transmission interface (2) ; and wherein, preferably, the rotation axis (J-J) of the rotative transmission element is oriented orthogonal to the rotation axis (X-X) of the return pulley.

13. A robotic system (10) for surgical or microsurgical teleoperation comprising a surgical instrument (1 ) according to any one of the preceding claims, and at least one motorized manipulator (1 1 ) comprising , preferably, at least one actuation interface which engages with the transmission interface portion of the surgical instrument.

14. The robotic system according to claim 13, wherein the frame (3) of the transmission interface portion (2) comprises a mounting portion (21 ) having a frustoconical insertion surface for blocking by mechanical interference in a central through hole provided in the motorized manipulator.

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