Articulated instrument for robotic microsurgery provided with an elastic opening element

Abstract

Surgical instrument (1 ) for a surgical robot (10) comprising an articulated end (2) comprising a first link (3) actuated by one or more tendons and comprising an attachment root (31 ) and an elongated body (32) forming at least one distal free end (33); a second link (4) actuated by one or more tendons and comprising an attachment root (41 ) and an elongated body (42) forming at least one free end (43); said first link (3) and said second link (4) are movable with respect to each other in a closing / opening direction; said elongated body (32) of the first link (3) comprises, in a single piece, its own elastic appendix (34) having its own free end (35) comprising an elastic element to bias the distancing of said first link and said second link; said second link (4) comprises an abutment wall (44) to abut against the appendix (34) of the first link for the purpose of elastically deforming the elastic appendix (34) of the first link (3) by loading it.

Description

"ARTICULATED INSTRUMENT FOR ROBOTIC MICROSURGERY PROVIDED WITH AN ELASTIC OPENING ELEMENT”DESCRIPTION

[0001] . Field of the invention

[0002] . The subject matter of the present invention is a surgical instrument for robotic surgery.

[0003] . The invention also relates to a system for surgical or microsurgical teleoperation comprising said surgical instrument.

[0004] . State of the art

[0005] . Robotic surgery apparatuses are generally known in the art and typically comprise a central robotic tower and one or more robotic arms extending from the central robotic tower. Each arm comprises a motorised positioning system (or robotic manipulator) for moving a surg ical instrument distally attachable thereto, in order to carry out surgical procedures on a patient.

[0006] . The patient typically lies on an operating table placed in the operating room, wherein sterility is ensured to avoid bacterial contamination due to the non-sterile parts of the robotic apparatus.

[0007] . Generally, known surgical instruments for teleoperated robotic surgery comprise a proximal transmission interface (or “backend”, according to English terminology commonly adopted in the field) having an interface intended to be operated by a robotic manipu lator.

[0008] . Extending from the proximal transmission interface of the surgical instrument there is an elongated element such as a shaft, or a rod or a stem having , at its distal end, an articulated device (e .g . a robotic wrist) with an operative end (e.g . needle holder, scissors, dilator, chisel) .

[0009] . Known surgical instruments having an articulated wrist are typically composed of a plurality of links actuated by a plurality of tendons (oractuation cables) .

[0010] . -Apart from known surgical instruments comprising an articulated wrist, other surgical instruments are also known having an articulated device of the “snake” type, that is, comprising a plurality of stacked vertebrae movable with respect to one another by a pl urality of actuation cables or tendons.

[0011] . The provision of said wrist links, as well as said stacked vertebrae, with their actuation tendons, makes it possible to move the operative end of the instrument according to various degrees of freedom.

[0012] . Typically, in fact, articulated ends possess at least three deg rees of freedom of movement, commonly referred to as roll, pitch and yaw. In addition, when at least two tips or end jaws are provided, a further opening / closing degree of freedom between the tips or jaws is present, which can act as a degree of freedom for g ripping and / or cutting when at least one of the end tips is provided with a blade having a cutting edge. For example, prior document WO-2022-269421 in the name of the same Applicant shows a solution of a surg ical instrument of the needle / scissors holder type in which one of the two tips is provided with a blade in its portion proximal to the gripping surfaces of the tips or jaws.

[0013] . To carry out the cutting , it is known to arrange two blades on two respective tip links, which are moved by pulling their respective actuation tendons. In particular, by pulling the respective tendons the blades are brought closer until their mechanical interference i s achieved carrying out the cutting action.

[0014] . Usually, springs are interposed between the two blades, such as, for example, Belleville-type elastic washers fitted on the pivot pin of the blades, for the purpose of applying an elastic preload in the axial direction to keep the blades in mutual contact during the mechanical interference that provides the cutting action, as shown, for example, in prior document US-2019-0105032.

[0015] . However, the known solutions are not free from drawbacks and, in particular, prove unsuitable for an advanced miniaturisation of the blades and, more generally, of the surgical instrument.

[0016] . Furthermore, prior document US-2024-277370 in the name of the same Applicant shows a solution of a miniaturised cutting surgical instrument, thanks to the absence of springs fitted on the pin, that is, this solution provides to localise the axial elasticity, aimed at keeping the blades in mutual contact, on the blade itself, thus avoiding axial play between the blades at their articulation pin. In one embodiment shown, in particular, the counter-blade is “T”-shaped having two free ends, a proximal one facing the pin and the other distal, to ensure an adequate cutting action over a wide range of opening angles between the blades, that is, this solution makes it possible to achieve excellent cutting quality both at the tip and at the base.

[0017] . This solution, although advantageous from many points of view, and in particular for allowing an advanced miniaturisation of the articulated cutting end and a good cutting quality along the entire length of the cutting edge, proves incapable of providing a prompt cutting response and, in particular, is not free from drawbacks such as jamming and locking of the blades upon closing , with the impossibility of reopening or, conversely, sudden and uncontrolled opening thereof.

[0018] . In particular, the friction exchanged between the two blades to carry out the cutting action, considering that, at the microscale, surface forces such as friction become dominant over volume forces, may cause jamming of the blades themselves, which are actuated by tendons, whereby an increase of the traction force of the tendons may be required in an attempt to open the scissors, that is, the blades, which consequently may result in sudden or jerky opening of the scissors themselves.

[0019] . This undesirable dynamic behaviour under operating conditionsproves difficult to predict, that is, to model it mathematically, as well as limiting the performance of an instrument for clinical use.

[0020] . In the case of miniaturised surgical instruments without blades, a similar problem sometimes arises, especially when the actuation tendons have a substantially elastic or elasto-plastic behaviour for small traction forces applied at their ends, imposing a slow opening response of the jaws or tips, which can cause jerks and reduce control over the behaviour of the operative articulated end under operating conditions.

[0021] . Furthermore, during the service life of the surgical instrument in the operating environment, contact with biological fluids often leads to the formation of mechanical play between the moving parts of the articulated end itself. Such play, even if minimal, can deeply deteriorate the response time of these miniaturised articulated surg ical ends. Adhesion conditions of the end tips may occur in conditions of complete closure of the jaws also due to external agents such as biological or body fluids that, when dried or completely dry on significant surfaces or joint portions, prevent proper opening .

[0022] . There is therefore a strong need to devise a gripping and / or cutting surgical instrument solution suitable for advanced miniaturisation and at the same time capable of providing a prompt response under operating conditions.

[0023] . Solution

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

[0025] . This and other objects are achieved with a surgical instrument according to claim 1 .

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

[0027] . According to one aspect of the invention, a surg ical instrument fora surg ical robot comprises an articulated end. Said articulated end comprises a first link comprising an attachment root and an elongated body forming a distal free end, and a second link comprising an attachment root and an elongated body forming at least one distal free end.

[0028] . The first link and said second link are movable with respect to each other, providing a closing / opening degree of freedom of the articulated end. Preferably, said first and second links are actuated by actuation tendons.

[0029] . The elongated body of the first link comprises, in a single piece, its own elastic appendix having its own free end. Said elastic appendix comprises an elastic element for biasing said first link and said second link in the opening movement direction. The second link comprises an abutment wall to abut against the elastic appendix of the first link for the purpose of elastically deforming the elastic appendix of the first link by loading it.

[0030] . The relative movement between said first link and said second link preferably occurs circumferentially around an articulation pin of both said first and second links.

[0031] . According to one embodiment, the first link further comprises a closure stop arranged, during closure, beyond said elastic appendix. In other words, the closure stop is arranged, on the first link, circumferentially beyond the elastic appendix in the closing movement direction .

[0032] . According to one embodiment, said first link and said second link define an opening angle therebetween, and said elastic element of the elastic appendix preloads, in the opening movement direction said first link and said second link for a fraction of said opening angle, thereby defining an elastically preloaded angular stroke. Preferably, said elastically preloaded angular stroke is adjacent, in the circumferential direction, to the closure stop.

[0033] . According to one embodiment, operative portions of said first link and of said second link are located near or at the respective distal free ends, so that, when in operative conditions, an opening angle equal to the elasticallypreloaded angular stroke causes exposure of the operative portions out of the mutual circumferential footprint.

[0034] . According to one embodiment, said abutment wall of the second link is arranged on a protrusion of the second link that extends cantilevered axially to abut, in the circumferential direction, against said elastic appendix of the elongated body of the first link.

[0035] . Preferably, the elastic appendix of the elongated body of the first link is suitable for elastically flexing during closure to bias during opening said first link and said second link, and according to one embodiment, is also suitable for elastically flexing in the axial direction to carry out a cutting action.

[0036] . According to one embodiment, said elastic appendix of the elongated body of the first link extends proximally, with its own free end facing the attachment root of said first link.

[0037] . Thanks to the proposed solutions, it is possible to make an articulated end having an elastically preloaded range of movement between the two tip links of the articu lated end .

[0038] . Thanks to the proposed solutions, it is possible to localise all the elastic deformation in the elongated body of the tip links, avoiding providing springs at the level of the link roots.

[0039] . Thanks to the proposed solutions, an advanced miniaturisation of the first link, the second link and the articulated end of the surgical instrument is made possible, making it particularly suitable for use in robotic microsurgical teleoperation.

[0040] . Brief description of the figures

[0041] . Further features and advantages of the invention will appear from the description given below of preferred embodiments, provided by way of example and not limitation, with reference to the accompanying figures in which :

[0042] . - Figure 1 A is an axonometric view of a surgical robot, according to one embodiment;

[0043] . - Figure 1 B is an axonometric view of a surgical instrument, according to one embodiment ;

[0044] . - Figure 2 is an exploded axonometric view of an articulated end, according to one embodiment ;

[0045] . - Figures 3A and 3B are plan views of a second link of the articulated end of Figure 2, wherein Figure 3B is taken according to the viewpoint indicated by arrow B in Figure 3A ;

[0046] . - Fig ures 4A, 4B and 4C are plan views of a first link of the articulated end of Figure 2, wherein Figure 4B is taken according to the viewpoint indicated by arrow B in Figure 4A, and wherein Figure 4C is taken according to the viewpoint indicated by arrow C in Figure 4A ;

[0047] . - Figure 5 is an axonometric view of a portion of an articulated end when in a closing configuration ;

[0048] . - Figure 6 is a schematic sectional view illustrating an articulated end when in a closing configuration, according to one embodiment ;

[0049] . - Figure 7 is an axonometric view showing an articu lated end when in a closing configuration, according to one embodiment ;

[0050] . - Fig ure 8 is a vertical elevation view pictorially illustrating an articulated end, according to one embodiment ;

[0051] . - Figure 9 schematically illustrates the first link of the articulated end of Figure 8 ;

[0052] . - Figure 1 0 is a pictorial view of an articulated end, wherein the second link is shown in section ;

[0053] . - Figure 1 1 shows the first link of the articulated end of Figure 1 0.

[0054] . It should be noted that references to “one embodiment” in this description are not necessarily references to the same embodiment, and are to be understood as referring to at least one. Moreover, for reasons ofconciseness and reduction of the total number of figures, a certain figure may be used to illustrate features of more than one embodiment, and not all elements of the figure may be necessary for a particular embodiment.

[0055] . Detailed description of some embodiments

[0056] . Reference throughout this description to “one embodiment” is intended to indicate that a particular feature, structure or function described in connection with the embodiment is included in at least one embodiment of the present invention. Therefore, the expression “in one embodiment” in various parts of this description does not necessarily refer to the same embodiment. Moreover, particular features, structures or functions such as those illustrated in different figures may be combined in any suitable manner in one or more embodiments.

[0057] . According to a general embodiment, a surgical instrument 1 for robotic surgery comprises an articulated end 2.

[0058] . The surgical instrument 1 may be suitable for removable mounting to a robotic manipulator 8 of a system for surgical teleoperation 1 0, that is, a surgical robot 1 0 preferably configured to carry out master-slave teleoperation. The surgical instrument 1 preferably comprises a proximal transmission interface portion 9, for receiving the actuation manipu lation action from the robotic manipulator 8 under the control of at least one master driving device (not shown) , and an elongated positioning shaft 1 1 , which is preferably rigid but may be flexible, bearing at its distal end said articulated end 2. Inside the body of the elongated positioning shaft 1 1 , the actuation tendons (not shown) of the articulated end are preferably arranged, extending from the transmission interface portion 9 to the articulated end 2 to transmit, through the transmission of traction forces to the articulated end, the manipulation action applied by the robotic manipulator 8 of the surgical robot 10 to the transmission interface portion 9 of the surgical instrument.

[0059] . The articulated end 2 preferably comprises a plurality of links androtational joints between them actuated by actuation tendons, such as, for example, an articulated wrist having two rotational joints with orthogonal axes Y-Y and P-P and two tip links 3, 4 which may comprise one or more blades 30, 40 (for example formed by a cutting edge of the link body) and which are movable in the closing / opening direction . Clearly, the articulated end 2 may be of the “snake” type comprising a plurality of stacked vertebrae actuated by actuation tendons.

[0060] . The articulated end 2 comprises a first tip link 3 (or first link 3) comprising an attachment root 31 and a longitudinally extended el ongated body 32 forming at least one free end 33. The attachment root 31 serves to articulate the first link 3 to a supporting structure, such as, for example, a proximal supporting link 7 having a clevis structure (according to commonly used terminology) which mounts an articulation pin to which said first link 3 is articulated. The articulation pin (not shown) is preferably a small cylindrical pin extending along the direction of the distal articulation axis Y-Y or yaw axis Y-Y. The elongated body 32 of the first link is made in a single piece with said attachment root 31 and preferably also with said distal free end 33. The attachment root 31 preferably comprises one or more seats 37 for receiving at least one actuation tendon, and for example, a seat 37 is provided which receives two tendons with antagonistic effects and comprises two opposite undercut walls forming the dragging abutment for respective distal ends of said two antagonistic tendons.

[0061] . The articulated end 2 comprises a second tip link 4 (or second link 4) comprising an attachment root 41 and a longitudinally extended elongated body 42 forming at least one free end 43. The attachment root 41 is intended to articulate the second link 4 to a supporting structure, such as, for example, a proximal supporting link 7 having a clevis structure (according to terminology commonly used in the relevant technical field) which mounts an articulation pin to which said second link 4 is articulated. The articulation pin (not shown)is preferably a small cylindrical pin extending along the direction of the distal articulation axis Y-Y or yaw axis Y-Y and is preferably the same articu lation pin for the first link 3. Two pins may be provided, each to individually articu late its respective link 3, 4 with respect to the supporting structure 7. The elongated body 42 of the second link is made in a single piece with said attachment root 41 and preferably also with said distal free end 43. The attachment root 41 preferably comprises one or more seats 47 for receiving at least one actuation tendon, and for example, a seat 47 is provided which receives two tendons with antagonistic effects and comprises two opposite undercut walls forming the dragging abutment for respective distal ends of said two antagonistic tendons.

[0062] . The supporting link 7, when provided, may in turn be articulated to its own supporting structure, such as the shaft 1 1 , so that it can rotate together with the two tip links 3, 4 mounted thereon, with respect to a definable proximal articulation axis P-P, which may, for example, be orthogonal to the distal articulation axis Y-Y.

[0063] . The first link 3 and the second link 4, with their respective elongated bodies 32, 42, are preferably axially juxtaposed to one another, and the elongated bodies extend substantially longitudinally to the respective distal free ends 33, 42. In other words, each of said first link 3 and second link 4 comprises a body extending longitudinally from the attachment root to its respective distal free end, and in particular, the middle portion of said links is defined as the elongated body for the purposes of this description.

[0064] . Furthermore, the elongated bodies 32, 42 of the first link 3 and of the second link 4 are movable with respect to each other circumferentially (with respect to the distal articulation axis Y-Y) , that is, while closing / opening or relatively approaching / moving away. In fact, preferably, both said first link 3 and second link 4 are articulated to the supporting l ink 7 to rotate relatively about the distal yaw articulation axis Y-Y, thus defining a closing / openingdirection, wherein while the attachment roots 31 and 41 rotate around the Y- Y axis remaining always juxtaposed, the elongated bodies 32 and 42 move relatively approaching and moving away and can result overlapped, that is, axially juxtaposed, to carry out a gripping and / or cutting action.

[0065] . Therefore, in the articulated end of the surgical instrument, an axial direction, parallel to the articulation axis Y-Y, a radial direction R-R, orthogonal to the articulation axis Y-Y and incident thereto, and a circumferential direction C-C, orthogonal both to the axial direction and to the radial direction, can be defined. Therefore, each of said first link 3 and second link 4 comprises an elongated body 32, 42 extending substantially radially in the articulated end and facing distally. In other words, the elongated body 32, 42 of each of said first link 3 and second link 4 extends along its own longitudinal direction, which is substantially the above-defined radial direction R-R. Therefore, the above-defined circumferential direction C-C is the closing / opening direction, that is, the relative approaching / moving away direction of the operative portions of said first link and second link.

[0066] . According to a preferred embodiment, the first link 3 and the second link 4 are axially adjacent to each other, that is, in a direction parallel to the articulation axis Y-Y of the links 3 and 4, and both said links 3, 4 are mounted on the supporting link 7, and preferably, the first link 3 and the second link 4 are articulated, by means of the same articulation pi n, with respect to the supporting link 7, so that they can rotate relative to each other about the articulation axis Y-Y.

[0067] . As mentioned above, the first link 3 and the second link 4 may each be articulated by its own articulation pin with respect to the supporting link, said articulation pins being parallel to each other.

[0068] . According to a preferred embodiment, the attachment roots 31 , 41 are in intimate contact with each other, avoiding providing springs therebetween, for example Belleville-type springs fitted onto the articulationpin, in order to promote miniaturisation since it avoids having to manufacture and assemble micro Belleville springs around the articulation pin between the attachment roots of said first and second links.

[0069] . Preferably, the first link 3 and the second link 4 are also in intimate contact with the prongs 27 of the supporting link 7 (clevis) , achieving a stacked, compact structure without the interposition of springs at the level of the roots, that is, at the proximal attachment parts of said links. This further promotes miniaturisation of the articulated end, even in the case that at least one of said first link and second link is provided with a blade to carry out a cutting action by mechanical interference sliding contact with the other link, because the elasticity necessary to carry out the cutting action is entirely provided on the elongated body of the blade itself.

[0070] . As mentioned above, said first link 3 and said second link 4 are movable with respect to each other in a closing / opening direction. In this way, a closing / opening deg ree of freedom is achieved, wherein when approaching each other they move relatively in the closing direction 6, while when moving away from each other they move relatively in the opening direction. Abutment surfaces may be provided, for example in the case of an articulated en d capable of carrying out a g ripping action, and / or sliding surfaces, for example in the case of an articulated cutting end in which at least one between the first link and the second link comprises a blade with a cutting edge to carry out a cutting action when in mechanical interference with the other link between said first link and second link.

[0071] . Said first link 3 and said second link 4 are each provided with a respective operative portion, the operative portions being intended for cutting and / or gripping anatomical structures and / or suturing instruments. Preferably, said operative portions are located at least near or at the distal free end 33, 43 of the respective link 3, 4. In operating conditions, indeed, it may happen that a surgeon prefers to operate, with a cutting surg ical instrument, usingonly the distal portion of the blade arranged near or at the distal free end of the link. Similarly, in the case of a gripping surgical instrument, the gripping surfaces are typically arranged near the distal free ends 33, 43 of the links.

[0072] . The attachment roots 31 , 41 preferably have a substantially discoidal body. The actuation dragging exerted by the actuation tendons on the attachment roots 31 , 41 of the links 3, 4 can take place by exerting a dragging action against surfaces arranged radially (that is, extending radially from the articulation axis Y-Y) and, for example, provided in specially shaped holes inside the discoidal body of the respective attachment root. The attachment roots further preferably comprise an axial through-hole 26 for receiving the articu lation pin.

[0073] . The closing / opening direction in the relative approaching / moving away direction does not necessarily follow a circu lar trajectory around the articulation axis (pin) Y-Y, and according to one embodiment, the movement between the first link 3 and the second link 4 is guided linearly, and in that case the pin, if provided, is not an articulation pin but a linear guide, and the direction of relative approaching / moving away between the links 3, 4 is the axial direction with respect to the pivot axis, and / or it is possible that the body of the attachment roots is not discoidal but has a geometry adapted for guided linear movement.

[0074] . To promote advanced miniaturisation of the articulated end 2, each of said first link 3 and second link 4 is preferably made in a single piece, for example in surgical steel machined by wire electroerosion, and free of moving parts such as pulleys for guiding the tendons. The actuation tendons are preferably polymeric and are mounted in a sliding manner on the articulated end, that is, they are fixed at their respective attachment roots and mounted on the articulated end, for example on the supporting link 4, so that they can slide on smooth sliding surfaces provided in a single piece on the body of the supporting link.

[0075] . When in operating conditions, each attachment root 31 , 41 of the link 3 or 4 is mou nted on the articulation pin; each distal free end 33, 43 is therefore movable with respect to the other distal free end, and the elongated body 32, 42, or at least its operative portion 13, 14, such as a gripping surface and / or a cutting edge, carries out the mechanical gripping and / or cutting action together with the other elongated body, that is, the elongated body of the other link.

[0076] . Advantageously, said elongated body 32 of the first link 3 comprises, in a single piece, its own elastic appendix 34 having its own free end 35, said elastic appendix 34 of the first link 3 comprising an elastic element 5 for biasing the moving away of said first link 3 and said second link 4. The relative movement for distancing the first link and the second link is directed in the opening direction along the closing / opening direction (circumferentially) .

[0077] . Said elastic appendix 34 of the first link 3 is preferably an elongated body suitable for flexural deformation in the closing direction 6, thereby constituting said elastic element 5.

[0078] . The free end 35 of the elastic appendix 34 of the first link 3 is separate from the distal free end 33 of the same first link 3, and therefore the first link 3 comprises two free ends 33 and 35, which can be oriented, that is, facing in different directions (for example, one distally and the other proximally) .

[0079] . With further advantage, the second link 4 comprises an abutment wall 44 to abut against the appendix 34 of the elongated body 32 of the first link 3 for the purpose of elastically deforming said elastic element 5 of the elastic appendix 34 of the first link 3 by loading it. The free end 35 may have a rounded shape to promote contact with the abutment wall 44 of the second link.

[0080] . In this way, an elastic element 5 is arranged between the first link3 and the second link 4, which elastically biases the distancing of said first and second link. The elastic element 5 of the elastic appendix 34 of the first link 3 is suitable for being elastically loaded in flexion during the closing of the first and second link, to bias while opening said first link 3 and said second link 4.

[0081] . When in operating conditions, therefore, an elastic impulse is provided, aimed at automatically distancing said first link 3 and said second link 4 when closing force is no longer exerted by traction of the actuation tendons of said first and second links. In this way, therefore, automatic reopening between said first link and said second link is achieved. At the same time, during the closing movement, that is, the relative approaching of said first and second links, the elastic element 5 acts as a preload spring , allowing increased control of movement and avoiding play and jerky motions that could be caused by friction between the moving parts (the links 3, 4, the articulation pin, the supporting link 7) , as well as compensating for possible elongations of the actuation tendons (which may therefore be made of braided polymeric fibres) . Furthermore, this allows operation without play for small successive closing and opening movements between said first and second links, providing a prompt and jerk-free response.

[0082] . According to one embodiment, the abutm ent wall 44 is provided on the attachment root 41 of the second link 4. According to another embodiment, the abutment wall 44 is provided on the elongated body 42 of the second link 4, avoiding being provided on the free end 43 or on the attachment root 41 of the second link.

[0083] . The abutment wall 44 may be provided on an appendix 45 or on a projection 45 of the second link 4. In particular, the appendix 45 or projection 45 of the second link 4 extends axially in cantilever fashion, that is, protrudes in a direction parallel to the articulation axis Y-Y, from the second link 4 to impact the first link 3, which is axially adjacent thereto, and in particular toimpact the elastic appendix 34 of the first link 3. In other words, the projection 45 extends in the axial direction by a certain extent such as to overlap, in the closing / opening direction, the elastic appendix 34 of the first link 3. The appendix 45 or axially projecting portion 45 of the second link 4 preferably protrudes from the attachment root 41 and comprises a body extending axially towards the first link 3. The configuration of said projection 45 is preferably thick and rigid so as to be undeformable axially when in contact with said elastic appendix 34 of the first link 3, in such a manner as to deform it elastically du ring the relative approaching , while closing , of the articulated end of said first and second links.

[0084] . The elastic appendix 34 with its elastic element 5 is preferably shaped in such a way as to be elastically loaded in flexion, that is, by flexing in the closing direction to bias the distancing of said first and second links.

[0085] . It is possible to define, between said first link 3 and said second link 4, when articulated to rotate with respect to each other about the articulation axis Y-Y, an opening angle along the closing / opening direction. In other words, the opening angle between said first and second link may be defined with radii extending from the articulation pin on the supporting link 7 and touching the respective free ends 33 and 43 of said first and second links. The opening angle is therefore a measure of the degree of closing / opening between said first and second links. According to a preferred embodiment, said elastic element 5 of the appendix 34 of the first link relatively preloads, the distancing , that is, while opening , of said first link and said second link for a fraction p of said opening angle, achieving an elastically preloaded angular stroke p. In this way, when the first link and the second link are close to each other in the closing direction, that is, when the articulated end 2 is semi closed, or substantially closed, or essentially closed, the elastic element 5 is elastically loaded. The relative approaching action (closing) between said first and second links is produced by the traction exerted by the respectiveactuation tendons (which, as mentioned above, may terminate on their respective attachment roots) .

[0086] . By providing the elastic action localised in the final part of the closing movement range (small opening angle) and more precisely up to the achievement of complete closure of the instrument and / or axial overlapping of the elongated bodies 32, 42 of said first and second links, it is made possible that the elastic force starts acting in the final closing step with a small resisting force, such as to allow greater control, resolution and precision in the closing movement; while in the opening step it provides an advantageous elastic impulse capable of overcoming possible frictional, jamming or resisting forces between the surfaces of the two contacting links 3, 4 and of unlocking them in case of jamming or mutual adhesion, as well as in case of jamming / adhesion with the supporting link 7 (its prongs 27) or the articulation pin .

[0087] . According to a preferred embodiment, said elastic appendix 34 of the first link 3 comprises its own abutment surface 28 facing in the closing / opening direction to come into contact with the abutment wall 44 of the axially projecting projection 45 of the second link 4. The abutment surface 28 of the elastic appendix 34 of the first link 3 may be arranged on an axial recess of the elongated body 32 of the first link 3, and in particular on an axial recess of the body of the elastic appendix 34.

[0088] . Clearly, the elastic appendix 34 of the first link, since it extends in cantilever fashion between the attachment root 31 and the distal end 33 of the first link 3, belongs to the elongated body 32 of said first link 3. Therefore, thanks to the proposed solutions, it is possible to localise entirely the necessary elasticity in the elongated body 32 of the link 3.

[0089] . Furthermore, where the first link 3 and the second link 4 are configured to carry out a cutting action, it is possible to concentrate all the elasticity necessary for the cutting action and for the automatic reopening between said first and second links in the elongated body of said first andsecond links. This avoids having to design and assemble elastic elements at the articulation pin , that is, between the attachment roots 31 , 41 , thereby promoting extreme miniaturisation of the components and of the articulated end 2, as well as at the distal free ends 33, 43, keeping them free and suitable for fine manipulation or cutting of biological tissues and / or for fine manipulation of surgical instruments (needles and suture threads, for example).

[0090] . According to a preferred embodiment, the first link 3 comprises a closure stop 36, intended to abut, that is, to make mechanical contact against the abutment wall 44 of the second link 4. The closure stop 36 of the first link 3 is arranged, in the closing direction 6, beyond said elastic appendix 34. The closure stop 36 of the first link 3 preferably has a thick configuration to prevent elastic deformation. Therefore, when in operating conditions, for small or very small opening angles, that is, in a closed articulated end configuration, the first link 3 and the second link 4 are elastically preloaded distancing them (that is, while opening) until reaching the closure stop 36 (continuing their relative approaching movement in the closing direction 6) .

[0091] . The elastically preloaded angular stroke p in the closing / opening direction and arranged between the abutment of the elastic appendix 34 and the abutment of the stop 36 of said first link 3 is preferably equal to or smaller than 1 0°. According to one embodiment, as shown, for example, in Figure 6, the elastically preloaded angular stroke p in the closing / opening direction 6 between the abutment of the elastic appendix 34 and the abut ment of the stop 36 is of a few degrees, and, for example, belongs to the range of 1 °-3°, and preferably is substantially equal to 1 °.

[0092] . The abutment against the closure stop 36 is preferably such as to coincide with the complete closure of the instrument (very small or zero opening angle) and / or with a specific predetermined value of partial axial overlapping of the elongated bodies 32, 42 of said first and second links (as,for example, in the case of surg ical scissors) .

[0093] . The preferred operative portions 1 3, 14 of said first link and said second link are located near or at the respective distal free ends 33, 43, so that, when in operating conditions, an opening angle equal to the elastically preloaded angular stroke p still exposes the operative portions 13 , 14 out of the mutual circumferential footprint. In other words, an elastically preloaded angular stroke of 1 0° may achieve an opening between the links 3 and 4 such as to expose the distal free ends 33, 43 with their operative portions 13, 14, allowing the surgeon to operate within an elastic range, that is, an elastically preloaded range. Indeed, it may be desirable for the surgeon to maintain an opening angle of a few degrees both to carry out the cutting action near or at the distal free ends 33, 34 and in the case of carrying out a gripping action near the distal free ends 33, 34.

[0094] . In the case of an articulated end 2 capable of carrying out a gripping or surg ical g rasping action, such as in the case of an articulated end of the needle / scissors holder type and / or surgical forceps and therefore provided, on each of said first link 3 and second link 4, near the respective distal free ends 33, 43, with operative portions 13, 14 that are gripping surfaces 25 for carrying out the gripping or surgical grasping action, said gripping surfaces may act as closure stop surfaces, as shown, for example, in Figure 8. In such a case, as shown, for example, in Figure 9, the elastic appendix 34 of the first link 3 may extend in cantilever fashion towards the second link 4 in the closing direction 6, bringing its free end 35 beyond the angular level, in the closing direction of the gripping surface of the same second link 3, which is arranged near the distal free end 33 of the first link.

[0095] . When the first link 3 comprises a gripping surface near its distal free end 33, does not necessarily also act as a stop, and, as shown, for example, in Figures 10-11 , a separate stop 36 may be provided, arranged near or at the attachment root 31 .

[0096] . According to a preferred embodiment, as shown, for example, in Figure 4A, said elastic appendix 34 of the first link 3 extends proximally with its free end 35 facing the attachment root 31 of said first link 3. In this way, the free end 35 of the elastic appendix 34, that is, the second free end of said first link, is a proximal free end 35 facing opposite said distal free end 33 of the same first link 3. This embodiment is particularly advantageous in the case when said first link 3 comprises a blade 30 for carrying out a cutting action in cooperation with the second link 4. The second link 4 may also comprise its own blade 40. As mentioned above, in the case where the articulated end 2 is an articulated end suitable for carrying out a cutting action, such as surgical scissors or needle / scissors holder, the cutting action may be carried out by axially overlapping (in a direction parallel to the articulation pin) the elongated bodies 32, 42 of the first and second links, bring ing them into a condition of mechanical interference, wherein at least one of the elongated body of the first link or the second link comprises its own blade 30 or 40. To promote the miniaturisation of the articulated end , said at least one blade 30, 40 concentrates on itself all the elastic deformation required to carry out the cut, which is directed axially or has a substantial axial component in the case of a torsional deformation.

[0097] . Therefore, in the case where the first link 3 comprises its own blade 30 elastically deformable under flexion and / or torsion in at least the axial direction, said same first link 3 also comprises said elastic appendix 34 with said elastic element 5 to be elastically loaded, preferably under flexion, along the closing / opening direction 6. In other words, the elongated body 32 of the first link 3 may comprise, according to a preferred embodiment, both an elastic appendix 34 that provides an elastic preload in the opening direction, that is, in a substantially circumferential direction around the articulation axis Y-Y, and an elastic blade 30 elastically deformable in the axial direction, that is, in a direction parallel to the articulation axis Y-Y of said first link 3 withrespect to said supporting link 7.

[0098] . In particular, the provision of a blade 30 on said elongated body 32 of the first link 3 having two opposite free ends 33, 35 allows supplying unusual elasticity to the blade itself both in the opening / closing direction and in the axial direction. According to one embodiment, indeed, the elastic appendix 34 results deformable both circumferentially along the closing / opening direction and axially to carry out the cutting action, allowing on one hand to carry out a cutting action for large opening angles (that is, cutting near the proximal free end 35 thanks to its elasticity) and for small or very small opening angles (that is, near or at the distal free end 33) , while at the same time providing the elastic preload in the closing / opening direction 6 that tends to automatically reopen the blades 30, 40 of the surgical scissors. Clearly, the term “blade” is intended to indicate both a blade having its own cutting edge and a counter-blade, the counter-blade not necessarily having a cutting edge and acting as a mechanical interference abutment to axially flex the blade during the carrying out of the cutting action.

[0099] . According to a preferred embodiment, said first link 3 comprises two opposite free ends 33 and 35, a proximal free end 35 being provided on said elastic appendix 34 with said elastic element 5, and a dis tal free end 33, and a stop projection 36 arranged, in the closing direction 6, beyond the abutment surface 28 of the elastic appendix 34, said stop 36 extending axially to abut against the abutment wall 44 of the second link 4, wherein preferably said stop 36 of the first link also extends in the longitudinal direction from the attachment root 31 , forming its own distal end portion 38 arranged near the proximal free end 35 of the elastic appendix 34 and facing it. Between the proximal free end 35 of the elastic appendix 34 and the distal end portion 38 of the stop 36 of the same first link 3, a longitudinal gap 29 or long itudinal distance 29 may be defined. The distal end portion 38 of the stop projection 36, since the projection is thick and extends both axially and long itudinally,preferably has a wide surface facing the proximal free end 35, defining a longitudinal gap 29 therebetween. It is therefore made possible to arrange said closure stop 36 projection 35 and said elastic appendix 34 very close to one another, with minimal longitudinal distance, in such a manner that both may abut against the same abutment wall 44 of the same projection 45 of the second link 4 during the relative approaching (closing) movement of the first link 3 and the second link 4.

[0100] . Where said first link 3 comprises two opposite free ends 33 and 35, a proximal free end 35 being provided on said elastic appendix 34 with said elastic element 5, and a distal free end 33, and a stop projection 36 arranged beyond the abutment surface of the elastic appendix, a connecting arm 39 to the attachment root 31 may be provided, which extends from the attachment root up to a halfway portion of the blade 30, that is, a halfway portion between the two distal and proximal free ends 33, 35, forming a sort of “T”-shaped structure for the elongated body 32 of the first link 3. The provision of the connecting arm 39 makes it possible to further impart elasticity to the blade 30 of the first link 3. Furthermore, in this case, the seat 37 that receives the actuation tendon of the first link 3 may be interposed and delimited, in the axial direction, between the proximal free end 35 of the elastic appendix 34 and the arm 39.

[0101] . According to a general embodiment, a surg ical robot 1 0 for microsurgical teleoperation is provided, comprising at least one surgical instrument 1 according to any of the embodiments previously described.

[0102] . Thanks to the features described above, provided separately or jointly with each other in specific embodiments, it is possible to meet the aforementioned needs, achieving the above-stated advantages, and in particular:

[0103] . - an extreme miniaturisation of the articulated end is promoted, because elasticity is arranged on the elongated bodies of the tip links thatextend longitudinally between the attachment roots and the distal free ends of said links ;

[0104] . - an elastic device for the automatic reopening of the articulated end, such as surgical scissors, surgical forceps, or needle / scissors holder, is achieved ;

[0105] . - at the same time, a very fine control is allowed over opening and / or closing micro-movements of the distal free ends of the articulated end, which, by reason of the elastic preload between them , are free from play and jerky motion;

[0106] . - it allows the compensation of possible linear or non -linear elongations localised on the actuation tendons of the miniaturised articulated end ;

[0107] . - it makes it possible, therefore, to develop a predictive mathematical model of the behaviour of the articulated cutting and / or gripping end during microsurgical teleoperation ;

[0108] . - it allows the manufacturing of the links of the articulated end by wire electroerosion, carrying out two cuts on orthogonal cutting planes;

[0109] . - it makes it possible to use a portion of the body of the tip link itself to create a hinge-type joint that ensures controlled, mathematically modellable, and play-free movement.

[0110] . It is understood that the combinations of features disclosed in the appended claims form an integral and essential part of the present description.

[0111] . To the embodiments described above, a person skilled in the art, in order to meet contingent and specific requirements, may make numerous modifications, adaptations and replacements of elements with other functionally equivalent ones, without however departing from the scope of the appended claims.LIST OF REFERENCE NUMERALS1 Surgical instrument2 Articulated end3 First link4 Second link5 Elastic element6 Closing direction7 Supporting link, or clevis8 Robotic manipulator9 Proximal actuation interface of the instrument10 Surgical or microsurgical teleoperation system, or surgical or microsurgical robot11 Positioning shaft of the surgical instrument13 Operative portion of the first link14 Operative portion of the second link25 Gripping or grasping surface26 Articulation hole of the attachment root27 Prong of the supporting structure or link28 Abutment surface of the elastic appendix of the first link29 Longitudinal gap or free longitudinal space30 Blade of the first link31 Attachment root of the first link32 Elongated body of the first link33 First free end of the first link34 Appendix of the first link35 Free end of the appendix of the first link, or second free end of the first link36 Closure stop of the first link37 Seat of the first link38 Distal end surface of the stop39 Arm40 Blade of the second link41 Attachment root of the second link42 Elongated body of the second link43 Free end of the second link44 Abutment wall45 Projection or appendix of the second link47 Seat of the second linkY-Y Articulation axis of the articulation pinR-R Radial direction C-C Circumferential direction DISTAL Distal direction or orientation PROXIMAL Proximal direction or orientation

Claims

CLAIMS1. Surgical instrument (1 ) for a surg ical robot (1 0) comprising an articulating end (2) comprising :-a first link (3) comprising an attachment root (31 ) and an elongated body (32) forming a distal free end (33) ;- a second link (4) comprising an attachment root (41 ) and an elongated body (42) forming at least a free end (43) ; wherein-said first link (3) and said second link (4) are movable in relation to each other defining a closing / opening degree of freedom of the articulating end ;- said elongated body (32) of the first link (3) comprises in a single piece its own elastic appendix (34) having its own free end (35) and comprising an elastic element to bias while opening said first link and said second link;- said second link (4) comprises an abutment wall (44) to abut against the elastic appendix (34) of the first link with the purpose of elastically deforming the elastic appendix (34) of the first link (3) by loading it.

2. Surgical instrument according to claim 1 , wherein the first link (3) further comprises a closure stop arranged, while closing , beyond said elastic appendix (34) .

3. Surgical instrument according to claim 2, wherein said closure stop extends from the attachment root (31 ) towards the free end (35) of the elastic appendix (34) .

4. Surgical instrument according to any one of the preceding claims, wherein said first link (3) and said second link (4) define an opening angle therebetween; and wherein said elastic element of the elastic appendix preloads while opening said first link and said second link for a fraction of said opening ang le, thereby defining an elastically preloaded angular stroke (P).

5. Surgical instrument according to claim 4, wherein said elastically preloadedangular stroke (P) is adjacent, in the circumferential direction, to the closure stop; wherein, preferably, said elastically preloaded angular stroke (P) extends by an angle that is equal to or less than 1 0°; and / or wherein said elastically preloaded angular stroke (P) is located in the final part of the range of relative movement between said first l ink (3) and said second link (4) .

6. Surgical instrument according to claim 4 or 5, wherein operative portions (13, 14) of said first link and of said second link are located near or at the respective distal free ends (33, 43), so that, when in operative conditions, an opening angle equal to the elastically preloaded angular stroke (P) causes exposure of the operative portions (13, 14) out of the mutual circumferential footprint.

7. Surgical instrument according to any one of the preceding claims, wherein said abutment wall (44) of the second link (4) is arranged on a protrusion (45) of the second link that extends cantilevered axially to abut, in the circumferential direction, against said elastic appendix (34) of the elongated body of the first link.

8. Surg ical instrument according to any one of the preceding claims, wherein the elastic appendix (34) of the elongated body of the first link is suitable for elastically flexing while closing to bias the opening of said first link and said second link.

9. Surgical instrument according to claim 8, wherein the elastic appendix (34) of the elongated body of the first link is also suitable for elastically flexing in the axial direction to carry out a cutting action.

10. Surgical instrument according to any one of the preceding claims, wherein said elastic appendix (34) of the elongated body of the first link extends proximally, with its own free end (35) facing the attachment root (31 ) of said first link.1 1 . Surgical instrument according to claim 10, wherein the elongated body ofthe first link comprises a linking arm (39) extending from the attachment root (31 ) up to a halfway portion between the two free ends (33, 35) of the first link, thereby forming a sort of “T”-shaped structure for the elongated body (32) of the first link; and wherein, preferably, both free ends (33, 35) of the elongated body of the first link are suitable for elastically deforming in the axial direction to carry out a cutting action, and / or wherein the elastic appendix comprises a blade (30) .

12. Surgical instrument according to any one of the preceding claims, wherein the attachment roots (31 , 41 ) are in intimate and direct mutual contact, avoiding having to provide springs therebetween ; and wherein, preferably, the attachment roots (31 , 41 ) are also interposed between prongs of a supporting structure in intimate and direct contact, thereby resulting in a packed structure without springs.

13. Surgical instrument according to any one of the preceding claims, wherein at least one of the first link (3) and the second link (4) comprises a blade (30; 40) to carry out a cutting action.

14. Surgical instrument according to any one of the preceding claims, wherein the closure stop of the first link is located near or at the first attachment ro ot (31 ) ; and / or wherein the abutment wall (44) of the second link is located near or at the second attachment root (41 ) .

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