Joe operating mechanism

Abstract

an actuation mechanism comprising: a first jaw rotatable about a jaw axis and having a first slot; a second jaw rotatable about the jaw axis and having a second slot; a slider movable along a slider axis between a first position and a second position and movably engageable with the first and second jaws, the slider comprising a first protrusion slidably receivable in the first slot and a second protrusion slidably receivable in the second slot, each slot extending along a direction non-parallel to the slider axis when a respective protrusion is engaged with the slot; an actuating member mountable to a mechanism and operably engageable with both the slider and the return, the actuating member having a first end, a second end, a first portion extending from the first end to the return, and a second portion extending from the return to the second end, the first portion being securable to the slider, whereby movement of the first portion away from the return moves the slider towards the first position and movement of the second portion away from the return moves the slider towards the second position.

Description

Technical Field

[0001] The present invention relates to an actuating mechanism, and more particularly, but not limited thereto, to an actuating mechanism that facilitates the actuation of two jaw members by a single pair of tendons. The present invention has particular utility in the field of surgical robotics to facilitate the actuation of two jaw members that form part of the end effector of a surgical instrument for minimally invasive surgery. However, the present invention is not limited to such applications and can also be used in other medical / surgical devices or robotic devices having a tendon-driven end effector with two or more possible parts such as jaw members.

[0002] In this specification, the present invention is mainly described in relation to its application in the field of surgical robotics. However, this is for illustrative purposes only and does not exclude the application of the present invention in other fields.

Background Art

[0003] Known surgical instruments that form part of a robotic surgical system include a shaft, a joint section, and an end effector. The shaft can extend from other components of the surgical robot that control and drive the movement of the joint section and the end effector. Thereby, the shaft can facilitate the positioning of the joint section and the end effector in the required area of the patient. The joint section may include a plurality of joints positioned adjacent to each other to provide degrees of freedom of movement of the end effector relative to the shaft. Finally, the end effector may be adapted to perform specific operations required for the surgical procedure.

[0004] Known end effectors include, for example, end effectors having two movable jaw members such as grippers, forceps, shears, and dissectors. Some known end effectors are tendon-driven, which means that each possible joint movement of the end effector is caused by the tension of a tendon fixed to the end effector or a part of the end effector. Further, known end effectors are driven by pairs of antagonistic tendons so that each joint movement can be reliably reversed. For example, if the actuation of the jaw member in the first direction is caused by the tension of the first tendon, the actuation of the jaw member in the second opposite direction may require the tension of the second (antagonistic) tendon. SUMMARY OF THE INVENTION

[0005] According to a first aspect of the present invention, an actuating mechanism is provided. The actuating mechanism includes a first jaw that is rotatable about a jaw axis and has a first slot, a second jaw that is rotatable about the jaw axis and has a second slot, and a slider that is movable along a slider axis between a first position and a second position and is movably engagable with the first and second jaws. The slider includes a first protrusion that is slidably receivable within the first slot and a second protrusion that is slidably receivable within the second slot. Each slot extends along a direction non-parallel to the slider axis when the respective protrusion engages with the slot. The actuating mechanism further includes a return that is attachable to the actuating mechanism and is spaced apart from the slider when attached to the actuating mechanism, and an actuating member that is operably engagable with both the slider and the return. The actuating member includes a first end, a second end, a first portion extending from the first end to the return, and a second portion extending from the return to the second end. The first portion is fixable to the slider such that movement of the first portion away from the return causes the slider to move toward the first position, and movement of the second portion away from the return causes the slider to move toward the second position. , the return includes a pulley rotatable about a return axis, the actuating member passes around the pulley between the first part and the second part, the return axis is coaxial with the joe axis, and further includes a housing having a first guide and a second guide. When the slider moves along the slider axis, the first protrusion is guided by the first guide, and the second protrusion is guided by the second guide. 。

[0006] In use, when the slider moves along the slider axis between the first position and the second position, each of the first and second protrusions may slide within its respective slot. Since each slot extends in a direction non-parallel to the slider axis, movement of each protrusion within its respective slot causes the slot to move relative to the slider axis. Movement of each slot is facilitated by rotation of its respective joe about the joe axis, and thus, movement of the slider causes the joe to rotate about the joe axis. Further, each joe, particularly each slot, may be configured such that the joes rotate about the joe axis in opposite directions relative to each other. That is, movement of the slider causes the first joe to rotate in a first direction and the second joe to rotate in a second direction opposite the first direction.

[0007] The first portion of the actuating member extends from the first end of the actuating member to the return, and may be fixed to the slider such that movement of the first portion away from the return during use causes the slider to move away from the return to the first position. In other words, by pulling the first end of the actuating member away from the return, the slider moves towards the first position. The second portion of the actuating member extends from the return of the actuating member to the second end and is not fixed to the slider. During use, movement of the second portion away from the return causes the first portion of the actuating member to move towards the return, and thus, the slider moves towards the second position. Thus, by pulling the second end of the actuating member away from the return, the slider moves towards the second position.

[0008] Accordingly, according to the present invention, by actuating a single actuating member, both the first and second joes of the actuating mechanism can be simultaneously rotated in opposite directions relative to each other. Further, by actuating the actuating member antagonistically, each joe can be rotated in a first direction or a second direction opposite the first direction. In other words, by moving the first portion of the actuating member away from the return, the joes rotate towards each other, while by moving the second portion of the actuating member away from the return, the joes rotate away from each other.

[0009] When an actuation mechanism is used to actuate an end effector of a robotic surgical instrument, for example, the actuation member may extend through a joint of the surgical instrument. The actuation member is narrow and flexible and, more specifically, may be a tendon, rope, wire, thread, string, or other type of member suitable for facilitating similar actuation means.

[0010] In some known end effectors, each jaw is driven by a separate pair of antagonistic tendons. This means that four tendons are required for the operation of the end effector, rather than a single tendon with a first and second portion. Each tendon will have associated moving parts that drive the actuation of the tendon and convert the movement of the tendon into movement of each respective jaw of the end effector. Such known end effectors may be limited in terms of how small the surgical instrument can be made to accommodate all four tendons and associated moving parts, and how cost - effectively it can be manufactured while still including all of the motors and other components necessary to drive those four tendons. The present invention overcomes these drawbacks because only one tendon is required for the first and second portions that each extend through the surgical instrument. Accordingly, the surgical instrument may be more compact since it has fewer tendons to accommodate. Also, since there is only one tendon, the number of associated moving parts may be halved, if not further reduced.

[0011] The amount of force applied by Joe and the possible rotation angle each depend on the angle of the slot with respect to the slider axis. As the slider moves along the slider axis, each projection transmits force to each Joe through its respective slot. A portion of that force is consumed to rotate the Joe around the Joe axis, a portion is consumed to overcome the friction between the projection and the slot, and the remainder is transmitted to the Joe and could potentially be applied by the Joe when it opens and closes. When the slider is in a given position, as the angle between each slot and the slider axis becomes shallower, the rotation of the Joe per unit of slider movement along the slider axis decreases, and thus the force consumed to rotate the Joe decreases. With a shallower angle, the force required to overcome the friction between the projection and the slot also decreases. Thus, with a shallower angle, a larger magnitude of force is transmitted to the Joe, and this force could potentially be applied by the Joe when it opens and closes.

[0012] Conversely, as the angle between each slot and the slider axis increases, the Joe will rotate more per unit of slider movement along the slider axis at the expense of the magnitude of force that could potentially be applied by the Joe.

[0013] The angle of the slot with respect to the slider axis and the shape of the slot may be adapted to suit the application such that the force applied by the Joe is appropriate when the slider is in a given position along the slider axis. Further, the angle and shape of the slot may be adapted to be able to apply different magnitudes of force when the Joe is positioned at different rotation angles with respect to the Joe axis. This may allow for optimization of the force for a particular application.

[0014] Each of the slots can extend linearly or non-linearly. A linear slot provides a simpler relationship between the joe position and the applied force and thus enables a more intuitive use of the actuating mechanism. A non-linear slot enables a greater variety of possible relationships between the joe position and the applied force. This relationship can be more complex, which may enable the actuating mechanism to be more optimized for the application in which the actuating mechanism is used.

[0015] In an embodiment of the present invention, the return can comprise a pulley rotatable about a return axis, and the actuating member can pass around the pulley between a first portion and a second portion.

[0016] In such an embodiment of the present invention, the pulley can reduce the friction resulting from the engagement between the actuating member and the return by moving either the first end or the second end away from the return when the actuating member actuates antagonistically. The reduced friction can provide advantages such as improved durability of the actuating member, reduced energy required to operate the actuating member, and / or improved performance of the actuating member as a slider, and thus the joe operates more accurately and there is a lower likelihood of backlash or jerky movement.

[0017] In an embodiment of the present invention, the return may further comprise an axle extending along the return axis and supporting the pulley.

[0018] In such an embodiment of the present invention, the pulley may be rotatable about the axle, the axle may be rotatable about the return axis, or both.

[0019] In other embodiments of the present invention, the return may be fixed relative to the return axis, and the return and / or the actuating member may be adapted such that the actuating member can slide on the return with a low coefficient of friction.

[0020] In an embodiment of the present invention, the return shaft may be coaxial with the joe shaft. Further, in some embodiments of the present invention, the first and second joes may be rotatably engagable with an axle such that the first and second joes are supported by the axle and are rotatable about the axle.

[0021] In such an embodiment of the present invention, the longitudinal space occupied by the joe, the return, and the slider can be reduced by the joe and the pulley rotatable about the same axis and the same axle. Therefore, the operating mechanism may be overall more compact. The complexity of the operating mechanism is also reduced in terms of the number of required parts, which in turn reduces the manufacturing cost and improves the durability of the operating mechanism because there are fewer parts that may fail.

[0022] In an embodiment of the present invention, the actuating member may be slidably engagable with the slider between the return and the second end.

[0023] In such an embodiment of the present invention, the second portion of the actuating member maintains a movable state with respect to the slider so that the slider can surely move in both the direction toward the return and the direction away from the return. Further, the slidable engagement between the second portion of the actuating member and the slider can improve the stability of the slider when the slider moves along the slider axis in response to the movement of the first portion of the actuating member. In particular, the possibility of the slider being twisted by the forces exerted on the first and second protrusions by each joe can be reduced.

[0024] In an embodiment of the present invention, the slider may include a first member receiving portion and a second member receiver portion, and the actuating member may be fixable to the slider via the first member receiving portion and may be slidably receivable within the second member receiving portion.

[0025] In such an embodiment of the present invention, the first and second member receivers may be formed separately from the rest of the slider and attachable thereto, or the first and second member receivers may be integral with the rest of the slider. For example, the first and second member receivers may be first and second ferrules attachable to the slider by any suitable means such as laser spot welding. Alternatively, the first and second member receivers may be first and second channels extending through the slider.

[0026] The first portion of the actuating member may be fixed to the first member receiver by any suitable means. For example, when the first member receiver is a ferrule, the ferrule may be crimped, adhered, laser spot welded or soldered to the actuating member.

[0027] In an embodiment of the present invention, each jaw may include a tool portion. By the movement of the slider towards the first position, the first and second jaws can rotate towards a closed configuration in which the tool portions contact each other. By the movement of the slider towards the second position, the first and second jaws can rotate towards an open configuration in which the tool portions are separated.

[0028] In such an embodiment of the present invention, the first and second jaws can be rotated between the closed configuration and the open configuration by actuating the first and second portions of the actuating member antagonistically.

[0029] In an embodiment of the present invention, the tool portion may be configured as a scissor blade, forceps, dissector or gripper. Further, in an embodiment of the present invention, the tool portion may be configured to form any suitable bipolar tool that can benefit from being driven by a single actuating member having first and second portions that can be actuated antagonistically. Accordingly, the actuating mechanism according to the present invention may be adapted to provide a series of devices suitable for performing different tasks.

[0030] In an embodiment of the present invention, the actuating mechanism may further include a housing having a first guide and a second guide. When the slider moves along the slider shaft, the first protrusion is guided by the first guide, and the second protrusion is guided by the second guide.

[0031] In such an embodiment of the present invention, the guide can support the slider to prevent the slider from rotating or twisting around the slider shaft due to the force exerted on the protrusion by the joystick.

[0032] The guide may be adapted to support the protrusion by any suitable means. For example, in some embodiments of the present invention, the first and second guides may be channels in which the protrusions can be slidably received. In other embodiments of the present invention, each guide may be a ridge, and each protrusion may include a channel in which the respective guide can be slidably received.

[0033] According to a second aspect of the present invention, a surgical instrument is provided. The surgical instrument includes a shaft, a joint coupled to the shaft, and an end effector coupled to the joint, and the end effector includes an actuating mechanism according to the first aspect of the present invention.

[0034] The surgical instrument may be used in a surgical operation and may be a robotic surgical instrument. The joint can operate to facilitate movement of the end effector relative to the shaft with up to six degrees of freedom. Further, the joint can be operated by a plurality of tendons extending along the shaft to, for example, an actuator and a motor that drive the actuation of the tendons.

[0035] In use, the end effector, the joint portion, and the shaft may be positioned relative to the patient as necessary so that the end effector can be operated (via the actuation of the joint portion), actuated via a drive mechanism, and perform the tasks required for the associated surgical procedure. More specifically, the end effector operates by actuating the first and second portions of the actuating member antagonistically to move the slider along the slider axis, thereby causing the jaw to rotate.

Brief Description of the Drawings

[0036] Here, the present invention will be described by way of example only with reference to the accompanying drawings.

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0038] First, referring to FIGS. 1 to 3, an actuating mechanism according to an embodiment of the present invention is generally designated by reference numeral 2. The actuating mechanism 2 includes a first jaw 4 and a second jaw 6 that are each rotatable about a jaw axis 8. Each jaw 4, 6 includes a tool portion 10. The jaws 4, 6 are rotatable between a closed configuration in which the tool portions 10 contact each other as shown in FIGS. 1 and 2, and an open position in which the tool portions 10 are spaced apart from each other as shown in FIG. 3.

[0039] In this embodiment of the invention, the tool portion 10 forms a gripper, but in other embodiments, the jaws 4, 6 may comprise a tool portion forming any suitable type of tool with jaws rotatable in two opposite directions, such as pliers, forceps or dissectors.

[0040] The actuating mechanism 2 also comprises a housing 12 adapted to conceal and protect the internal components of the actuating mechanism 2. Thereby, the risk that the moving parts are blocked, obstructed or damaged can be reduced. The housing 12 also has a substantially smooth, regular and continuous outer surface with minimal sharp edges or corners. When the actuating mechanism 2 is used as part of a surgical instrument, the housing 12 can protect the patient's internal tissue from the irregular surfaces of the parts of the actuating mechanism 2.

[0041] Now referring to FIGS. 2 - 6, and in particular as shown in FIGS. 2 and 3, the actuating member 2 further comprises a slider 14, a return 16 and an actuating member 18. Also, the first jaw 4 comprises a first slot 20 and the second jaw 6 comprises a second slot 22.

[0042] The slider 14 is movably engagable with the first and second jaws 4, 6 and is movable along the slider axis 24, in particular, between a first position as shown in FIG. 2 and a second position as shown in FIG. 3. The slider 14 includes a first projection 26 that is slidably receivable within the first slot 20 and a second projection 28 that is slidably receivable within the second slot 22 as shown in FIGS. 4, 5 and 6. Each slot 20, 22 extends in a direction non-parallel to the slider axis 24 when the respective projections 26, 28 are engaged with the slots 20, 22. Further, each slot 20, 22 includes a first end 21 positioned to receive the respective projections 26, 28 when the slider 14 is in the first position as shown in FIG. 2 and a second end 23 positioned to receive the respective projections 26, 28 when the slider 14 is in the second position as shown in FIG. 3. This means that the movement of the slider 14 causes the first jaw 4 to rotate in a first direction and the second jaw 6 to rotate in a second direction opposite to the first direction. More specifically, the movement of the slider 14 towards the first position causes the jaws 4, 6 to rotate towards the closed configuration, and the movement of the slider towards the second position causes the jaws 4, 6 to rotate towards the open configuration.

[0043] The angles of slots 20, 22 relative to slider shaft 24, and the shapes of slots 20, 22, may be adapted to suit the application. In particular, each slot 20, 22 may be adapted such that the angle of each slot 20, 22 when slider 14 is in a given position enables an appropriate magnitude of force to be applied by jaws 4, 6 when jaws 4, 6 rotate at a particular angle of rotation about jaw axis 8. For example, when the slider is in the first position (shown in FIG. 2), the shallower the angle between each slot 20, 22 and slider shaft 24, the greater the force that jaws 4, 6 may apply when jaws 4, 6 are in or near the closed configuration. This is because as the angle becomes shallower, less force is consumed to rotate jaws 4, 6 and overcome friction between the first and second projections 26, 28 and respective slots 20, 22. Increasing the force with which jaws 4, 6 can close may be particularly useful, for example, in surgical applications where jaws 4, 6 are used to grasp small objects such as needles. The ability to hold a needle as firmly as possible may improve the safety and reliability when using the actuating mechanism.

[0044] Return 16 can be attached to the actuating mechanism 2, more specifically to the housing 12, and is spaced apart from the slider 14. The actuating member 18 is operatively engagable with both the slider 14 and the return 16 and includes a first end 30, a second end 32, a first portion 34, and a second portion 36. The first portion 34 extends from the first end 30 to the return 16, while the second portion 36 extends from the return 16 to the second end 32. The first portion 34 can be fixed to the slider 14. This means that, as shown in FIG. 2, during use, movement of the first portion 34 away from the return 16 causes the slider 14 to move towards the first position. Conversely, as shown in FIG. 3, movement of the second portion 36 away from the return 16 causes the first portion 34 to move towards the return, and thus the slider 14 to move towards the second position. As described above, movement of the slider between the first position and the second position causes the jaws 4, 6 to rotate between a closed configuration and an open configuration, respectively. Thus, antagonistic actuation of the actuating member 18 causes articulation of the jaws 4, 6.

[0045] As shown particularly in FIG. 4, the return 16 includes a pulley 38 and an axle 40. The axle 40 is supported by the housing 12 and extends along a return axis 42. The axle 40 then supports the pulley 38 which is rotatable about the return axis 42. In this embodiment of the invention, the pulley 38 is freely rotatable about the axle 40 so as to reduce the friction it experiences when the actuating member 18 actuates in either direction, i.e., when either the first end 30 or the second end 32 is moved away from the return 16. In other embodiments of the invention, the pulley may be fixed to the axle, the axle may be rotatable relative to the housing, or the pulley and axle may be fixed, and the pulley may be adapted, for example, to facilitate sliding of the actuating member over the pulley with a low coefficient of friction.

[0046] In this embodiment of the present invention, the return shaft 42 is coaxial with the joe shaft 8, as shown in FIGS. 1 to 3. Further, the first and second joes 4, 6 are rotatably engagable with the axle 40 such that the joes 4, 6 are supported by the axle 40 and rotatable about the axle 40. By positioning the return 16 such that the return shaft 42 is coaxial with the joe shaft 8, the longitudinal space required for the joes 4, 6, the return 16, and the slider 14 is reduced, and the entire operating mechanism 2 can be made more compact. Also, the complexity of the operating mechanism 2 is reduced in terms of the number of required parts, and the number of parts that may fail is reduced, so that the manufacturing cost is reduced and the durability of the operating mechanism 2 is improved.

[0047] The slider 14 includes a first member receiving portion 44 and a second member receiver portion 46. The actuating member 18 can be fixed to the slider 14 between the first end 30 and the return 16 via the first member receiving portion 44. Further, the actuating member 18 is slidably engagable with the slider 14 between the return 16 and the second end 32, and more specifically, is slidably receivable within the second member receiving portion 46. The slidable engagement between the second portion 36 of the actuating member 18 and the slider does not directly affect the movement of the slider 14 along the slider shaft 24, but can improve the stability of the slider 14 when the slider 14 moves along the slider shaft 24. In particular, the possibility that the slider 14 is twisted by the forces exerted on the first and second protrusions 26, 28 by the respective joes 4, 6 can be reduced.

[0048] In this embodiment of the present invention, the first and second member receivers 44, 46 are the first and second ferrules 45, 47 respectively attached to the slider via joints 48 as shown in FIG. 5. Each joint 48 can be created by laser spot welding or other suitable means for attaching the ferrule to the slider. To fix the first portion 34 of the actuating member 18 to the slider 14, the first ferrule 45 is crimped onto the actuating member 18. On the other hand, since the second ferrule 47 remains uncrimped, the actuating member 18 can slide freely through the second ferrule 47.

[0049] Now referring to FIG. 6, the housing 12 comprises a first guide 50 and a second guide 52. In use, as the slider 14 moves along the slider shaft 24, the first projection 26 is guided by the first guide 50 and the second projection 28 is guided by the second guide 52. In particular, the guides can support the slider 14 to prevent it from rotating or twisting about the slider shaft 24 due to the forces exerted on the projections 26, 28 by the jaws 4, 6.

[0050] In this embodiment of the present invention, the first and second guides 50, 52 are channels into which the projections 26, 28 can be slidably received. However, in other embodiments of the present invention, the guides may be adapted to support the projections by any suitable means. For example, each guide may be a ridge and each projection may comprise a channel into which the respective guide can be slidably received.

[0051] Any preference and option of a given aspect, feature, or parameter of the present invention should be considered to be disclosed in combination with any preference and option of all other aspects, features, and parameters of the present invention, unless the context otherwise indicates.

Claims

Claim 1 An actuating mechanism comprising: a first jaw rotatable about a jaw axis and having a first slot; a second jaw rotatable about the jaw axis and having a second slot; a slider movable along a slider axis between a first position and a second position and movably engageable with the first and second jaws, the slider comprising a first projection slidably receivable within the first slot and a second projection slidably receivable within the second slot, each slot extending along a direction non-parallel to the slider axis when the respective projection engages the slot, and a slider; a return attachable to the actuating mechanism and spaced from the slider when attached to the actuating mechanism; an actuating member operably engageable with both the slider and the return, the actuating member comprising a first end, a second end, a first portion extending from the first end to the return, and a second portion extending from the return to the second end, the first portion being fixable to the slider such that movement of the first portion away from the return causes the slider to move towards the first position and movement of the second portion away from the return causes the slider to move towards the second position; and the return comprising a pulley rotatable about a return axis, the actuating member passing around the pulley between the first portion and the second portion; the return axis being coaxial with the jaw axis; further comprising a housing having a first guide and a second guide, wherein when the slider moves along the slider axis, the first projection is guided by the first guide and the second projection is guided by the second guide. An actuating mechanism characterized by the above. Claim 2 The actuating mechanism according to claim 1, wherein the return extends along the return axis and further comprises an axle supporting the pulley. Claim 3 The actuating mechanism according to claim 2, wherein the first and second jaws are rotatably engageable with the axle such that the first and second jaws are supported by the axle and rotatable about the axle. Claim 4 The operating member is slidably engageable with the slider between the return and the second end, and the operating mechanism according to any one of claims 1 to 3 is characterized in that.

5. The slider includes a first member receiving portion and a second member receiving portion. The operating member can be fixed to the slider via the first member receiving portion and can be slidably received within the second member receiving portion. The operating mechanism according to claim 4 is characterized in that.

6. Each jaw includes a tool portion. By the movement of the slider toward the first position, the first and second jaws rotate toward a closed configuration in which the tool portions contact each other. By the movement of the slider toward the second position, the first and second jaws rotate toward an open configuration in which the tool portions are separated. The operating mechanism according to any one of claims 1 to 5 is characterized in that.

7. The tool portion is configured as a shearing blade, forceps, dissector or gripper. The operating mechanism according to claim 6 is characterized in that.

8. A surgical instrument comprising a shaft, a joint portion coupled to the shaft, and an end effector coupled to the joint portion. The end effector comprises an operating mechanism according to any one of claims 1 to 7, and the surgical instrument is characterized in that.

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