Actuation mechanism

Abstract

The actuation mechanism includes a first jaw rotatable about a jaw axis and including a first jaw engagement portion, a second jaw rotatable about the jaw axis and including a second jaw engagement portion, and a driver rotatable about a drive axis parallel to the jaw axis and including a first drive engagement portion and a second drive engagement portion. The first jaw engagement portion and the drive engagement portion are slidably engageable with each other, and the second jaw engagement portion and the drive engagement portion are slidably engageable with each other, such that when the first jaw engagement portion engages with the first drive engagement portion and the second jaw engagement portion engages with the second drive engagement portion, rotation of the driver about the drive axis causes the first jaw to rotate in a first sense and the second jaw to rotate in an opposite sense.

Description

[Technical field]

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

[0002] In this specification, the invention is mainly described with reference to its application in the field of surgical robotics, however, this is for the purpose of example only and does not exclude the application of the invention in other fields. [Background technology]

[0003] Known surgical instruments forming part of a robotic surgical system include a shaft, a joint, and an end effector. The shaft may extend from other components of the surgical robot that control and drive the movement of the joint and the end effector. The shaft may thereby facilitate positioning of the joint and the end effector to a required area of ​​a patient. The joint may include multiple joints positioned adjacent to one another to provide degrees of freedom of movement of the end effector relative to the shaft. Finally, the end effector may be adapted to perform a specific action required for a surgical procedure.

[0004] Known end effectors include end effectors with two movable jaw members, such as, for example, graspers, forceps, scissors, and dissectors. Known end effectors are also tendon-driven, meaning that each possible articulation of the end effector is caused by pulling a tendon affixed to the end effector or a part of the end effector. Furthermore, known end effectors are driven by antagonistic pairs of tendons to ensure that each articulation can be reversed. For example, if actuation of the jaw members in a first direction is caused by pulling a first tendon, actuation of the jaw members in a second, opposite direction may require pulling a second (antagonistic) tendon.

[0005] In some known end effectors, each jaw member may be driven by a separate pair of antagonistic tendons. However, this means that four tendons are required for the end effector to move, and each tendon has an associated moving part that drives the actuation of the tendon and translates the tendon's movement to a respective jaw member of the end effector. Such known end effectors may be limited by how small a surgical instrument can be made to accommodate all four tendons and associated moving parts, and how cost-effectively it can be manufactured with all of the motors and other components required to drive those four tendons. Summary of the Invention

[0006] According to a first aspect of the present invention, there is provided an actuation mechanism comprising: a first jaw rotatable about a jaw axis and having a first jaw engagement portion; a second jaw rotatable about the jaw axis and having a second jaw engagement portion; and a driver rotatable about a drive axis parallel to the jaw axis and having a first drive engagement portion and a second drive engagement portion, wherein the first jaw engagement portion and the first drive engagement portion are slidably engageable with each other and the second jaw engagement portion and the second drive engagement portion are slidably engageable with each other, such that when the first jaw engagement portion engages with the first drive engagement portion and the second jaw engagement portion engages with the second drive engagement portion, rotation of the driver about the drive axis causes the first jaw to rotate in a first sense and the second jaw to rotate in an opposite sense. One of the first jaw engagement portion and the first drive engagement portion has a first pin, and the other has a first slot extending along the radial direction of the driver, and one of the second jaw engagement portion and the second drive engagement portion has a second pin, and the other has a second slot extending along the radial direction of the driver. .

[0007] Rotation of each jaw may be caused by rotation of the driver due to the configuration of each jaw engagement relative to its respective drive engagement. For example, the first jaw engagement may be a fixed distance from the jaw axis and may be arranged such that when rotating about the drive axis, the first jaw engagement causes the first jaw engagement to rotate about the jaw axis while sliding relative to the first drive engagement. Meanwhile, the second jaw engagement and the second drive engagement may be complementarily configured such that the same rotation of the driver causes the second jaw to rotate in an equal and opposite direction.

[0008] Thus, in accordance with the present invention, both the first and second jaws of the actuation mechanism can be rotated or actuated simultaneously by rotating a single driver. The rotation of the driver can be driven by any means, such as via a motor drive shaft fixed to the driver, or via a pair of antagonistic tendons each attached to the driver.

[0009] In embodiments of the invention, the actuation mechanism may further comprise first and second tendons, each attachable to a driver.

[0010] In such an embodiment of the invention, the first and second tendons may form a pair of antagonistic tendons, where actuation of the first tendon rotates the driver in a first direction and actuation of the second tendon rotates the driver in the opposite direction. Thus, the actuation mechanism can be operated by actuating a single pair of antagonistic tendons. In other words, there is no need to require two separate pairs of antagonistic tendons (one for each jaw) to operate the actuation mechanism, as is the case with some known end effectors.

[0011] In some embodiments of the present invention, the first and second tendons may be joined or even integrally formed.

[0012] In embodiments of the invention, each jaw may further comprise a drive portion, a tool portion, and a jaw axle receiver positioned between the drive portion and the tool portion and extending along the jaw axis.

[0013] In such embodiments of the invention, the jaw axle receiver may include an opening extending along the jaw axis that may facilitate rotation of the jaw about the jaw axis. The tool portion may extend from the jaw axle receiver in a first direction perpendicular to the jaw axis and the drive portion may extend in a second direction substantially opposite the first direction. In some embodiments, the tool portion may be integral with the drive portion and in other embodiments, the tool portion may be separate but attachable to the drive portion.

[0014] In an embodiment of the invention, the first and second jaw engagement portions may be positioned on the drive portions of the respective jaws.

[0015] In such an embodiment of the invention, the drive portion of each jaw may be positionable to at least partially overlap the driver, suitable for mutual engagement of the respective jaw and drive engagement portion.

[0016] In embodiments of the invention, the tool portions of the first and second jaws may be configured as scissors, forceps, dissectors or graspers. Furthermore, in embodiments of the invention, the tool portions may be configured to form any suitable bipolar tool that can benefit from being driven by a single driver and optionally a single pair of antagonistic tendons. Accordingly, the actuation mechanism according to the invention may be adapted to provide a range of devices suitable for performing different tasks.

[0017] In an embodiment of the present invention, each jaw is rotatable between an open position and a closed position. Furthermore, the actuation mechanism is movable between an open configuration in which each jaw is in its open position and a closed configuration in which each jaw is in its closed position. In other words, the jaws can be opened and closed by rotating the driver. The driver and the two jaws may be continuously rotatable such that each jaw can be rotated to any position between its respective open and closed positions.

[0018] In embodiments of the invention, the actuation mechanism may further comprise a housing including a jaw axle extending along the jaw axis and rotatably receivable within the jaw axle receiver of each jaw such that each jaw is rotatable relative to the housing about the jaw axle.

[0019] In such an embodiment of the invention, the housing may be adapted to support each jaw and may at least partially conceal and protect the drive to reduce the risk of the pin and slot mechanism becoming blocked or jammed.

[0020] The housing also Made byThe actuation mechanism may be adapted to have a substantially smooth, regular and / or continuous exterior surface with minimal sharp edges or corners that may damage the patient's internal tissue when the actuation mechanism is used as part of a surgical instrument or robot. The housing may also be configured to protect the patient's internal tissue from the irregular surfaces of the drivers, drive members, and engagement members that form part of the actuation mechanism.

[0021] In an embodiment of the invention, the driver may further comprise a drive axle receiving portion, and the housing may further comprise a drive axle extending along the drive axis and rotatably receivable within the driver's drive axle receiving portion such that the driver is rotatable relative to the housing about the drive axle.

[0022] In such embodiments of the invention, the housing may be adapted to support the driver and may at least partially conceal and protect the driver and attached first and second tendons to reduce the risk of the driver and / or tendons being blocked, obstructed or damaged.

[0023] In an embodiment of the invention, the first jaw engagement portion may include a first pin, the second jaw engagement portion may include a second pin, the first drive engagement portion may include a first slot, and the second drive engagement portion may include a second slot.

[0024] In such an embodiment of the invention, each slot may be at a fixed distance from the drive axle receiver and therefore from the drive shaft. In use, rotation of the driver about the drive shaft causes the first and second slots to rotate about the drive shaft. As each of the slots rotates, the respective pins move to remain in the slot. Each pin may be at a fixed distance from the jaw axle receiver (and therefore from the jaw axis). This means that while the pins slide in their respective slots, the movement of the pins is restricted to rotation about the jaw axis. As each pin rotates about the jaw axis, each jaw rotates accordingly about the jaw axis. Thus, rotation of the driver causes rotation of the jaws. Each pin may be positioned relative to the jaw axle receiver and each slot may be positioned and oriented relative to the drive axle receiver such that the rotation of each jaw caused by the driver is in a direction opposite to the direction of rotation of the other jaw. In some embodiments of the invention, the degree of rotation of each jaw caused by the driver may be equal to the other jaw. In other words, the jaws may be substantially symmetrically movable with respect to each other. In other embodiments of the present invention, the driver can rotate the jaws different amounts, ie, asymmetrically with respect to one another.

[0025] In an embodiment of the invention, the first jaw engagement portion may include a first slot, the second jaw engagement portion may include a second slot, the first drive engagement portion may include a first pin, and the second drive engagement portion may include a second pin.

[0026] In such an embodiment of the invention, each pin may be a fixed distance from the drive axle receiver and therefore a fixed distance from the drive shaft. In use, rotation of the driver around the drive shaft causes the first and second pins to rotate around the drive shaft. As each of the pins rotates, the respective slots move so that the pins remain therein. Each slot may be a fixed distance from the jaw axle receiver and therefore a fixed distance from the jaw axis. This means that the movement of the slots is limited to rotation around the jaw axis while sliding to retain the respective pins in the slots. As each slot rotates around the jaw axis, each jaw rotates around the jaw axis accordingly. Thus, rotation of the driver causes rotation of the jaws. Each pin may be positioned relative to the drive axle receiver and each slot may be positioned and oriented relative to the jaw axle receiver such that the rotation of each jaw caused by the driver is in a direction opposite to the direction of rotation of the other jaw. In some embodiments of the invention, the degree of rotation of each jaw caused by the driver may be equal to the other jaw. In other words, the jaws may be substantially symmetrically movable with respect to each other. In other embodiments of the present invention, the driver can rotate the jaws different amounts, ie, asymmetrically with respect to one another.

[0027] In an embodiment of the invention, the first jaw engagement may include a first pin, the first drive engagement may include a first slot, the second jaw engagement may include a second slot, and the second drive engagement may include a second pin, each pin and slot arrangement may operate as described above.

[0028] The location of each pin and the location and orientation of each slot may be altered, whether it is a jaw engagement or a drive engagement. Furthermore, the performance of the actuation mechanism during use can be altered, adjusted and / or optimized by adapting the location and / or orientation of the pins and slots. For example, the ratio between the radius of the driver and the distance between each pin and the drive shaft is proportional to the force amplification factor of each jaw. In other words, the closer the pin is to the drive shaft, the greater the force that can be applied to it by rotating the driver, and the greater the force that each jaw can exert. Thus, the force exerted by the jaws when opening and closing from a given position can be increased or decreased by configuring each pin to be closer or further from the drive shaft when each jaw is in that position.

[0029] Additionally, the force that may be exerted by the slot on the pin depends on how closely the slot is parallel to the centerline of each jaw (i.e., the jaw centerline), where the jaw centerline extends through the jaw axis and the center of each pin. If the slot is substantially parallel to the jaw centerline, the force exerted between the slot and the pin is substantially perpendicular to the jaw centerline, and a smaller percentage of the force is lost to friction due to the angle. Conversely, if the slot is closer to perpendicular to the jaw centerline, the force exerted between the slot and the pin is at an acute angle, resulting in a loss in the amount of force transmitted to the jaw.

[0030] According to a second aspect of the invention there is provided a surgical instrument comprising a shaft, an articulation coupled to the shaft and an end effector coupled to the articulation, the end effector comprising an actuation mechanism according to the first aspect of the invention.

[0031] The surgical instrument may be used in a surgical procedure and may be a robotic surgical instrument. The joints may be actuated to facilitate movement of the end effector relative to the shaft with up to six degrees of freedom. Further, the joints may be actuated, for example, by a number of tendons extending along the shaft to actuators and motors that may drive actuation of the tendons.

[0032] During use, the end effector, joints and shaft may be positioned as required relative to the patient so that the end effector can be manipulated (through actuation of the joints) and actuated via the drive mechanism, more specifically by rotation of the driver, to perform the tasks required for the associated surgical procedure. [Brief description of the drawings]

[0033] The invention will now be described, by way of example only, with reference to the accompanying drawings.

[0034] [Figure 1] FIG. 2 is a schematic diagram of an actuation mechanism according to an embodiment of the first aspect of the present invention; [Diagram 2] FIG. 2 is a schematic diagram of the actuation mechanism shown in FIG. 1 with the jaws in an open position. [Diagram 3] FIG. 3 is a rear view of the actuation mechanism shown in FIG. 2. [Figure 4] FIG. 2 is a schematic diagram of the actuation mechanism shown in FIG. 1 with the jaws in a closed position. [Diagram 5] FIG. 5 is a rear view of the actuation mechanism shown in FIG. 4. [Figure 6a-6c] 1A-1D are schematic diagrams of an actuation mechanism according to another embodiment of the first aspect of the present invention, showing front, rear and side views respectively; [Figure 7a-7b] FIG. 6B is a schematic diagram of the actuation mechanism shown in FIGS. 6a, 6b and 6c showing the internal components and with the jaws in the closed position. [Figure 8a-8b] FIG. 6B is a schematic diagram of the actuation mechanism shown in FIGS. 6a, 6b and 6c showing the internal components and with the jaws in the open position. [Figure 9a-9b]4A-4D are schematic diagrams of an actuation mechanism according to another embodiment of the first aspect of the present invention, showing front and rear views respectively; [Figure 10a-10b] 4A-4D are schematic diagrams of an actuation mechanism according to another embodiment of the first aspect of the present invention, showing front and rear views respectively; [Figure 11a-11b] 4A-4D are schematic diagrams of an actuation mechanism according to another embodiment of the first aspect of the present invention, showing front and rear views respectively; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] 1, an actuation mechanism according to one embodiment of the present invention is generally designated by the reference numeral 2. The actuation mechanism 2 includes a first jaw 4, a second jaw 6, a driver 8, and a housing 40. Each jaw 4, 6 includes a jaw axle receiver 34, and the housing 40 includes a jaw axle 42. The jaw axle 42 extends along a jaw axis and is rotatably receivable within the jaw axle receiver 34 such that each jaw 4, 6 is rotatable relative to the housing 40 about the jaw axle 42.

[0036] Each jaw 4, 6 further includes a tool portion 32 formed thereon. Each jaw is rotatable about a jaw axle 42 between an open position in which the tool portions are spaced apart and a closed position in which the tool portions contact one another. In this embodiment of the invention, the tool portions 32 of the first and second jaws 4, 6 are configured as graspers, although in other embodiments of the invention the tool portions may be configured to form part of any suitable tool, such as scissors, forceps, or dissectors.

[0037] Each jaw 4, 6 further includes a drive portion 30 engageable with a driver 8. The driver 8 includes a drive axle receiver 36, and the housing 40 further includes a drive axle 44 extending along a drive axis parallel to the jaw axis. The drive axle 44 is rotatably receivable within the drive axle receiver 36 such that the driver 8 is rotatable relative to the housing 40 about the drive axle 44.

[0038] Although the drive shaft is spaced from the jaw shaft, the entire drive mechanism includes a driver and both jaw drives are compact. This is in contrast to some known bipolar end effectors that include bulky linkages to drive the jaw actuation. The relative compactness of the driver 8 and drive 30 allows for more efficient miniaturization of the actuation mechanism 2, which may be particularly advantageous in the fields of surgical robotics and minimally invasive surgical devices.

[0039] In this embodiment of the invention, the driver 8 is disc shaped. However, in other embodiments of the invention, the driver 8 may be of any suitable shape so long as it is rotatable about the drive axle 44.

[0040] Also, in this embodiment of the invention, the driver 8 is attachable to first and second tendons (not shown) that can each be actuated or pulled to rotate the driver 8 in different directions about the drive axle 44. In other embodiments of the invention, the driver 8 may be attachable to any suitable drive means for rotating it about the drive axle. For example, the drive axle 44 may be fixed to the driver 8, and the drive axle 44 may be rotatable by a motor attached to the housing 40.

[0041] 2 and 3 show each side of the actuation mechanism 2 of FIG. 1. The first jaw 4 includes a first jaw engagement portion, specifically a first pin 12, positioned on the first jaw drive portion 30, the second jaw 6 includes a second jaw engagement portion, specifically a second pin 14, positioned on the second jaw drive portion 30, and the driver 8 includes a first drive engagement portion (first slot 16) and a second drive engagement portion (second slot 18). In other embodiments of the invention, other arrangements of pins and slots between the jaws and the driver are possible. Examples of such other arrangements are described below with reference to FIGS. 9a-11b.

[0042] The first pin 12 is slidably engageable with the first slot 16 and the second pin 14 is slidably engageable with the second slot 18. In use, when each pin 12, 14 is engaged with its respective slot 16, 18, rotation of the driver 8 about the drive axle 44 causes each jaw 4, 6 to rotate about the jaw axle 42 in an opposite direction to the other jaw. Rotation of the jaws 4, 6 occurs because the first and second pins 12, 14 are a fixed distance from a jaw axis through which the jaw axle 42 extends and the first and second slots 16, 18 are positioned and oriented within the driver such that rotation about the drive axis through which the drive axle 44 extends causes the respective pins 4, 6 to rotate relative to the jaw axis while sliding within the slots.

[0043] Additionally, each pin 12, 14 is positioned in the drive of a respective jaw, and each slot 16, 18 is positioned and oriented in the driver such that when one of the jaws 4, 6 is in its open position, the other jaw is also in its open position, and when one of the jaws 4, 6 is in its closed position, the other jaw is also in its closed position. This allows the actuation mechanism 2 to move between a fully open and a fully closed configuration depending on the rotational position of the driver 8. Figures 2 and 3 show the open jaw configuration, and Figures 4 and 5 show the closed jaw configuration.

[0044] In this embodiment of the invention, the jaws 4, 6 move substantially symmetrically relative to one another, in other words, the range of movement of the first jaw 4 is substantially equal to the range of movement of the second jaw 106, so that in the open configuration, the first jaw 4 and the second jaw 6 have rotated substantially equal amounts from their respective closed configuration positions.

[0045] The advantage of the pin and slot mechanism is its simplicity and reliability. The entire actuation mechanism 2 consists of only three moving parts (the driver 8 and each of the jaws 4, 6). Also, the nature of the slidable engagement of each pin with its respective slot allows for a margin of imprecision that can be offset by simply rotating the driver further in one orientation or another (i.e., clockwise or counterclockwise). Accordingly, the actuation mechanism 2 can be manufactured cost-effectively, especially in comparison to some known end effectors that require complex, precisely engineered components to operate reliably and accurately.

[0046] Another advantage of the pin and slot mechanism is that the force exerted by the driver 8 on each pin is variable based on the ratio of the radius of the driver 8 to the distance between each pin 12, 14 and the drive shaft. This radius is proportional to the force amplification factor of the respective jaw members 4, 6. In other words, the greater the ratio of the radius of the driver to the distance between the pin and the shaft, the greater the force exerted by each jaw when opening and closing. Increasing the force exerted by the jaws when closed can be particularly advantageous in surgical applications, such as maintaining a strong grip on a suture needle.

[0047] A further advantage of the pin and slot mechanism is that the full range of movement achievable by the jaws is caused by small rotations of the driver (e.g., less than 180°) since each rotation of the driver rotates both jaws in the opposite direction, essentially doubling the effect of the rotation. This allows the movement of the jaws 4, 6 to be very responsive to the actuation of the driver 8. The size of the driver may also vary depending on the application in which the actuation mechanism 2 is used. For example, the driver 8 may be made smaller in applications where compactness is preferred and larger in applications where it is preferred that the jaws generate more rotational force (i.e., when more force is required for gripping or cutting).

[0048] 6a, 6b and 6c, an actuation mechanism according to another embodiment of the present invention is designated generally by the reference numeral 102. Actuation mechanism 102 is similar to actuation mechanism 2 shown in Figures 1-5 and, for ease of reference, like features have been given corresponding reference numerals. For example, actuation mechanism 102 includes a first jaw 104 that is similar to first jaw 4 of actuation mechanism 2 shown in Figures 1-5.

[0049] In this embodiment of the invention, the driver 108 is attachable to a first tendon 122 and a second tendon 124. Rotation of the driver 8 in a first direction, such as to rotate the jaws 104, 106 toward a closed position, may be achieved by actuating or pulling the first tendon 122. Conversely, rotation of the driver 8 in a second direction, such as to rotate the jaws 104, 106 toward an open position, may be achieved by actuating or pulling the second tendon 122.

[0050] Accordingly, a single pair of antagonistic tendons (first and second tendons 122, 124) may be used to actuate the actuation mechanism 102 between the closed configuration shown in Figures 7a and 7b and the closed configuration shown in Figures 8a and 8b.

[0051] In Figures 7a and 7b, the first jaw 104 includes a first pin 112, the second jaw includes a second pin 114, and the driver 108 includes first and second slots 116, 118 (similar to the actuation mechanism 2 shown in Figures 1-5). Highlighted in Figure 7a is a first jaw centerline 105 that extends through the jaw axis 142 from which the jaw axle 142 extends and the center of the first pin 112, while highlighted in Figure 7b is a second jaw centerline 107 that extends through the jaw axis and the center of the second pin 114.

[0052] In Figures 8a and 8b, the first tendon 122 has been pulled to rotate the driver 108 about the drive axis relative to the position the driver 108 held in Figures 7a and 7b, and to rotate the jaws 104, 106 such that the actuation mechanism 102 is now in an open configuration. In Figure 8a, the driver 108 has rotated counterclockwise relative to the orientation it had in Figure 7a, while the first jaw 104 and first jaw centerline 105 have rotated clockwise about the jaw axle 142. In Figure 8b, the driver 108 has rotated clockwise relative to the orientation it had in Figure 7b, while the second jaw 106 and second jaw centerline 107 have also rotated clockwise about the jaw axle 142.

[0053] In this embodiment of the invention, the jaws 104, 106 move asymmetrically relative to one another, in other words, the range of movement of the first jaw 104 is greater than the range of movement of the second jaw 106 such that in the open configuration, the first jaw 104 is rotated further from the closed configuration position than the second jaw 106.

[0054] In use, a force that can be exerted by one of the tendons 122, 124 on the driver 108 to rotate it is referred to herein as a tendon force. The driver 108 transmits the tendon force to each jaw 104, 106 through a respective slot 116, 118 which presses against a respective pin 112, 114. The force exerted by the slot 116, 118 on the pin 112, 114 is referred to herein as a driving force and acts perpendicular to the orientation of the slot. As each jaw 104, 106 pivots about the jaw axle 142, the driving force is transferred to a force exerted by each tool part. This force is the force that causes the jaws to open and close and is referred to herein as a gripping force. The gripping force exerted by each jaw acts perpendicular to the respective jaw centerline 105, 107. Thus, the proportion of each drive force acting perpendicular to each jaw centerline 105, 107 is transferred to the gripping force, while the proportion of the drive acting parallel to each jaw centerline is lost to friction.

[0055] Accordingly, an advantage of the pin and slot mechanism is that it can provide increased gripping force when high forces need to be exerted by the tool part.

[0056] 9a and 9b, an actuation mechanism according to another embodiment of the present invention is designated generally by the reference numeral 202. Several parts of actuation mechanism 202 correspond to parts of actuation mechanism 102 shown in Figures 6a-8b and have therefore been given the same reference numerals for ease of reference.

[0057] The actuation mechanism 202 differs from the actuation mechanism 102 shown in Figures 6a-8b in that the first and second drive engagement portions comprise first and second pins 212, 214 and the first and second jaw engagement portions comprise first and second slots 216, 218, rather than vice versa as in the actuation mechanism 2 shown in Figures 1-5. In other words, the first jaw 204 comprises a first slot 216, the second jaw comprises a second slot 218, and the driver 208 comprises first and second pins 212, 214. The first pin 212 is slidably engageable with the first slot 216 and the second pin 114 is slidably engageable with the second slot 218 such that rotation of the first and second jaws 204, 206 can be achieved by rotating the driver 208. In this embodiment of the invention, rotation of the first and second pins 212, 214 about the drive axis through which the drive axle 144 extends causes the respective slots 216, 218 to rotate relative to the jaw axis through which the jaw axle 142 extends such that each pin 212, 214 remains within its slot 216, 218.

[0058] The driver 208 may be attached to the first tendon 122 and the second tendon 124 in a manner similar to the driver 108 shown in Figures 6a-8b.

[0059] In other embodiments of the invention, it is possible to modify the pin and slot mechanism so that the driver has one pin and one slot, rather than both pins or both slots as described above.

[0060] For example, in Figures 10a and 10b, an actuation mechanism according to one embodiment of the present invention is generally designated by the reference numeral 302. The actuation mechanism 302 comprises a first jaw 104 and a second jaw 206. The actuation mechanism 302 comprises a driver 308 adapted to engage with the first and second jaws 104, 206. The driver 308 thus comprises a first slot (not shown here, but similar to the first slot 116 shown in Figures 7a-8b) which is engagable with a first pin (not shown here, but shown in Figures 7a-8b) forming part of the first jaw 104. The driver 308 also comprises a second pin 214, identical to the second pin 214 shown in Figures 91 and 9b, which is engagable with a second slot 218 of the second jaw 206.

[0061] Alternatively, in Figures 11a and 11b, an actuation mechanism according to one embodiment of the present invention is designated generally by reference number 402. The actuation mechanism 402 comprises a first jaw 204 and a second jaw 106. The actuation mechanism 402 comprises a driver 408 adapted to engage with the first and second jaws 204, 106. Accordingly, the driver 308 comprises a first pin 212 engageable with a first slot 216 forming part of the first jaw 204. The driver 308 also comprises a second slot (not shown, but similar to the second slot 118 shown in Figures 7a-8b) engageable with a second pin 118 (not shown here, but shown in Figures 7a-8b) of the second jaw 106.

[0062] Preferences and options of any given aspect, feature, or parameter of the invention should be considered as disclosed in combination with all preferences and options of all other aspects, features, and parameters of the invention, unless the context dictates otherwise.

Claims

1. An actuation mechanism comprising: a first jaw rotatable about a jaw axis and including a first jaw engagement portion; a second jaw rotatable about the jaw axis and including a second jaw engagement portion; a driver rotatable about a drive axis parallel to the jaw axis and including a first drive engagement portion and a second drive engagement portion; the first jaw engagement portion and the first drive engagement portion are slidably engageable with one another and the second jaw engagement portion and the second drive engagement portion are slidably engageable with one another, such that when the first jaw engagement portion engages with the first drive engagement portion and the second jaw engagement portion engages with the second drive engagement portion, rotation of the driver about the drive shaft causes the first jaw to rotate in a first sense and the second jaw to rotate in an opposite sense; One of the first jaw engagement portion and the first drive engagement portion includes a first pin, and the other includes a first slot extending along a radial direction of the driver; an actuation mechanism, wherein one of the second jaw engagement portion and the second drive engagement portion includes a second pin and the other includes a second slot extending radially along the driver;

2. The actuation mechanism of claim 1 , further comprising a first tendon and a second tendon each attachable to the driver.

3. 3. An actuation mechanism according to claim 1 or 2, wherein each jaw comprises a drive portion, a tool portion, and a jaw axle receiver, the jaw axle receiver being positioned between the drive portion and the tool portion and extending along the jaw axis.

4. 4. The actuation mechanism of claim 3, wherein each of the first and second jaw engagement portions is positioned on a drive portion of a respective jaw.

5. 5. An actuation mechanism according to claim 3 or claim 4, wherein the tool portions of the first and second jaws are configured as scissors blades, forceps, dissectors or graspers.

6. An actuation mechanism as claimed in any one of claims 3 to 5, wherein each jaw is rotatable between an open position and a closed position.

7. The actuation mechanism of claim 6 , wherein the actuation mechanism is movable between an open configuration in which each jaw is in its open position and a closed configuration in which each jaw is in its closed position.

8. a housing having a jaw axle; 8. An actuation mechanism as claimed in any one of claims 3 to 7, wherein the jaw axle extends along the jaw axis and is rotatably receivable within the jaw axle receiver of each jaw such that each jaw is rotatable relative to the housing about the jaw axle.

9. 9. The actuation mechanism of claim 8, wherein the driver further comprises a drive axle receiver and the housing further comprises a drive axle, the drive axle extending along the drive axis and rotatably receivable within the drive axle receiver of the driver such that the driver is rotatable relative to the housing about the drive axle.

10. 10. The actuation mechanism of claim 1, wherein the first jaw engagement portion comprises the first pin, the second jaw engagement portion comprises the second pin, the first drive engagement portion comprises the first slot, and the second drive engagement portion comprises the second slot.

11. 10. The actuation mechanism of claim 1, wherein the first jaw engagement portion comprises the first slot, the second jaw engagement portion comprises the second slot, the first drive engagement portion comprises the first pin, and the second drive engagement portion comprises the second pin.

12. 10. The actuation mechanism of claim 1, wherein the first jaw engagement portion comprises the first pin, the second jaw engagement portion comprises the second slot, the first drive engagement portion includes the first slot, and the second drive engagement portion comprises the second pin.

13. 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 comprising an actuation mechanism according to any one of claims 1 to 12.

Images