Patent Description:
Surgical operations require the making of an incision in order for the physician to access internal parts of the body. Minimally invasive surgeries are operations in which the size of the incision is limited to reduce the healing time, associated pain and risk of infection of the resulting wound. Minimally invasive surgeries are therefore preferable for the well-being of a patient. However, due to the reduced size of the incision, minimally invasive surgeries were initially restricted to relatively simple procedures.

In recent years a variety of surgical instruments has been developed to provide physicians with the ability to perform increasingly complex procedures as minimally invasive surgeries. Known surgical instruments comprise an end effector, such as mechanical forceps, graspers, a needle holder or scissors, that enable the performance of certain actions required in surgical procedures. The end effector may be coupled to an articulation portion of the surgical instrument which provides the end effector with a number of degrees of freedom, thus enabling the end effectors to perform complex manoeuvres necessary for surgical procedures. The articulation portion may then be coupled to a hollow shaft which allows the end effector to be positioned in a required part of the body. The shaft may in turn be coupled to a driver module of the surgical instrument which provides inputs that control the end effector and articulation portion. The overall surgical instrument is therefore able to perform relatively complex surgical techniques.

Known end effectors, articulation portions, shafts and combinations thereof are small in their maximum width or diameter, often less than <NUM>. However, these portions of known surgical instruments, and particularly the shaft, may extend over considerable lengths, often in excess of <NUM>. The narrow width and extended length of the surgical instrument enable surgical techniques to be performed as minimally invasive procedures.

Known surgical instruments such as that described above are of great benefit to surgical operations as they allow relatively complex surgical techniques to be performed in a minimally invasive way.

However, there are issues with known surgical instruments of the type described above.

The end effector and articulating portion of a known surgical instrument require articulation by a means that does not impact on the small size of the components. A known method of achieving this is to attach first ends of tendons to different parts of the end effector and articulation portion. The tendons then extend through the hollow shaft and second ends of the tendons are attached to some form of actuator in the driver module of the surgical instrument. Actuation of the tendons provides articulation of the end effector and articulation portion.

Known driver modules are complex because they comprise a large number of moving parts in order to actuate the tendons with great precision.

Known driver modules are also expensive. The complexity and number of the parts required result in a high overall cost of manufacturing the driver modules. Due to the expense of the driver modules, they are required to be used more than once in order to make them cost efficient. This results in issues relating to sterility as it is crucial that any portion of the surgical instrument, which may come in to contact with the patient, is sterile.

Known driver modules suffer from an issue referred to as 'backlash'. When a tendon is actuated, the portion of the surgical instrument the tendon is attached to moves in response to the tendon's actuation. In known driver modules it is possible that the momentum provided by the actuation of the tendon is not halted when the tendon stops moving because the tendon is flexible. As a result the relevant part of the surgical instrument may continue to move, despite the actuation of the tendon having stopped. The relevant part of the surgical instrument is therefore in a different position to that it is intended to be in.

Backlash has two negative implications. The first is that the physician controlling the surgical instrument may not have a clear view of the surgical instrument, if any view at all, therefore it is important that the surgical instrument is in exactly the position it is intended to be in, otherwise harm could be caused to the patient. The second implication is that when the physician comes to control the relevant part of the surgical instrument again through a new actuation of the tendon, there may be a period of 'lag' between actuation of the tendon and movement of the relevant part. In other words a certain amount of actuation of the tendon may be performed before the relevant part starts to move. This is due to the tendon needing to be tensioned again before it is able to impart force on the relevant part. Again, this results in the surgical instrument acting differently to what the controlling physician is expecting, which may result in unintentional movement of the surgical instrument that may harm the patient.

<CIT> discloses a surgical instrument holder comprising a carriage, a housing and a drive assembly, wherein the drive assembly includes a pulley, a belt and an annular member. The pulley is rotatably disposed within the housing and in operable engagement with a motor of the carriage such that actuation of the motor rotates the pulley.

<CIT> discloses surgical instruments for use in a surgical robot, wherein the surgical instruments are part of a translational instrument interface and are removably coupled to the surgical robot and a handle of the surgical robot is coupled to the translational instrument interface such that actuation at the handle causes movement of the end-effector for performing surgery.

<CIT> discloses a computer-assisted teleoperated surgery system comprising a teleoperated instrument actuation pod which includes a plurality of linear actuators arranged around a surgical instrument, wherein the linear actuators engage with actuator engagement members on the instrument and so drive movable parts on it.

<CIT> discloses a wire rope driven quick-change device with a transmission device and a drive device, wherein the transmission device is a quick-change structure, and multiple groups of transmission components of the transmission device have the structure of connecting blocks and multiple groups of drive components of the drive device are provided with the structure of sliders which drive the movement of the connecting blocks after snapping together with the connecting blocks. It makes the drive device of the tendon sheath into a quick-change form to realize the function of replacing consumables, and by using the spring tube to realize the docking with flexible medical equipment.

<CIT> discloses an endoscopic instrument for the connection to an operation robot, wherein the endoscopic instrument comprises an instrument housing, to which a shank with at least one instrument part arranged at the distal side of the shank connects distally. The instrument part and/or the shank are movable relative to the instrument housing and for this are each actively connected to control.

<CIT> discloses a flexible robotic endoscopy slave system comprising an endoscope body and a flexible elongate shaft extending therefrom into which at least one tendon driven robotic endoscopic instrument is insertable, a docking station with which the endoscope body is releasably dockable and a translation mechanism for selectively longitudinally displacing the endoscopic instrument(s) within the flexible elongate shaft when the endoscope body is docked. The translation mechanism can carry and selectively displace actuators that drive each robotic endoscopic instrument by way of tendons.

To solve the technical problems above, a driver module for actuating a tendon and a surgical instrument comprising the driver module according to the independent claims are provided. Further embodiments are specified in the dependent claims.

According to a first aspect of the invention there is provided a driver module for actuating a tendon, the driver module comprising:
a slider comprising a base portion, a tendon receiving portion and a body portion, the tendon receiving portion being spaced apart from the base portion and the body portion and extending from the base portion to the tendon receiving portion, the module further comprising a slider receiving portion having a first end and a second end and engageable with the base portion of the slider such that the slider is moveably attachable to the slider receiving portion.

By means of the present invention, a tendon may be actuated through movement of the slider. Because the base portion of the slider, which is engageable in a slider receiving portion, is spaced apart from the tendon receiving portion by means of the body portion, the tendon receiving portion may be aligned with a tendon to be controlled with the slider.

At the same time, the base portion may be suitably positioned to engage with a slider receiving portion to allow movement of the slider.

This may be advantageous when the driver module forms part of a surgical instrument comprising a shaft through which tendons extend in order to operate the surgical instrument. In such embodiments of the invention, the tendons may be readily received by the tendon receiving portion of the slider without the need to divert the tendon. This obviates the need for further components such as pulleys in order to appropriately direct the tendon.

In such embodiments, the tendon receiving portion may receive an end of a tendon that extends along a shaft and exits the shaft receiving portion. The end of the tendon may further be fixed to the tendon receiving portion by any suitable means such as crimping, glue or solder. For example, in some embodiments of the invention the tendon receiving portion may, itself, be crimped around the tendon in order to hold the received end of the tendon in place within the tendon receiving portion.

In embodiments of the invention the driver module comprises a shaft receiving portion positioned towards the first end of the slider receiving portion, wherein the tendon receiving portion is aligned with the shaft receiving portion.

In such embodiments of the invention, a tendon extending along a shaft may exit the shaft and be received by the tendon receiving portion without having to be significantly diverted.

In embodiments of the invention the body portion of the slider further comprises an alignment portion, the alignment portion being adapted to position the tendon receiving portion of the slider in alignment with the shaft aperture.

In such embodiments of the invention, the base portion of the slider may be engageable with the slider receiving portion in a position that is not aligned with the shaft aperture. The alignment portion may therefore extend from the base portion and, at least partially, across a space between the slider receiving portion and the shaft aperture to provide alignment of the tendon receiving portion with the shaft aperture.

In embodiments of the invention, the slider comprises a drive portion extending from the base portion such that the base portion is positioned between the body portion and the drive portion.

In such embodiments of the invention, the drive portion of the slider may extend away from the body portion and away from the base portion of the slider. Such an arrangement may lead to a more efficient design of the drive module since the drive portion of the slider will not interfere with the tendon receiving portion of the slider.

In embodiments of the invention, the slider receiving portion comprises a channel extending at least partially along the length of the slider receiving portion between the first end and the second end, the channel being adapted to receive the base portion of the slider, whereby the base portion is slideably moveable within the channel.

In embodiments of the invention, the channel is linear, although in other embodiments of the invention the channel may be curved, for example.

In embodiments of the invention, the channel is adapted to receive the base portion of the slider such that the base portion is slidably moveable within the channel. In other words, movement of the slider is constrained by the dimensions of the channel and is generally linear movement, although as explained above the movement could also follow a curved trajectory.

In embodiments of the invention, the channel may extend substantially from the first end of the slider receiving portion to the second end of the slider receiving portion. However, in other embodiments of the invention, the channel extends partially along the length of the slider receiving portion.

The driver module may further comprise a first roller having an axis, and configured to be axially rotatable, the first roller being positionable such that the axis of the first roller is normal to the base portion of the slider and engageable with the base portion of the slider such that the movement of the slider causes axial rotation of the first roller.

In such embodiments of the invention, the first roller will provide support to the slider when the slider moves along the slider receiving portion. This can help to minimise friction during movement of the slider.

The driver module may further comprise a second roller having an axis, and configured to be axially rotatable, the first and second rollers being spaced apart from one another, the first roller being engageable with the first side of the base portion, and the second roller being engageable with the second side of the base portion.

In such embodiments of the invention, a slider is supported at a first end and second end during movement within the slider receiving portion.

This can provide additional support and further reduce friction during movement of the slider.

According to the invention, the driver module further comprises a pre-tensioning actuator, the pre-tensioning actuator being moveable between a first position and a second position, wherein, in the first position the pre-tensioning actuator is engaged with the slider such that the slider is positioned towards the second end of the slider receiving portion, and wherein in the second position the pre-tensioning actuator is disengaged with the slider, the driver module further comprising a bias for biasing the pre-tensioning actuator towards the first position.

In such embodiments, with the pre-tensioning actuator in the first position the slider is moved toward the second end of the slider receiving portion, away from the shaft receiving portion. Therefore, a tendon (extending along a shaft, exiting the shaft and received by the tendon receiving portion of the slider) may be held in tension by the slider as the pre-tensioning actuator is biased towards moving the slider away from the shaft receiving portion and associated shaft. This is advantageous when the surgical instrument is not being used as maintaining tension within the tendon helps keep the tendon in good condition.

Alternatively, when the pre-tensioning actuator is in the second position, the slider is able to move freely up and down the slider receiving channel which is advantageous when the surgical instrument is being used as the slider does not experience any resistance to movement that might negatively affect its actuation of the tendon.

In embodiments of the invention, the driver module further comprises a deactivating device engageable with the pre-tensioning actuator and moveable to a deactivating position, wherein the pre-tensioning actuator is configured to its second position.

In such embodiments, when the driver module is to be used, the deactivating device may be moved to its deactivating position hence configuring the pre-tensioning actuator to its second position to enable free movement of the slider. Movement of the deactivating device to its deactivating position may be achieved inherently when the driver module is engaged with a barrier in preparation to use the surgical instrument.

In embodiments of the invention, the driver module comprises a plurality of sliders, each of which sliders is engageable with the slider receiving portion.

In such embodiments of the invention, the slider receiving portion comprises a plurality of channels spaced apart from one another each of which channels being engageable with one of the sliders.

In such embodiments of the invention, each slider will be engageable with one of the plurality of channels.

By means of the present invention, a plurality of tendons may be actuated through movement of the plurality of sliders. Further, the plurality of tendons may include a pair of tendons coupled to one another such that the pair of tendons act antagonistically to one another. In other words, if one of the pair of tendons is pulled in one direction then the other of the pair of tendons is consequently pulled in the opposite direction.

Therefore, in some embodiments, each of a pair of antagonistic tendons may be attached to a respective one of the plurality of sliders. A first of the sliders may be actuated in a first direction, thereby pulling its respective tendon in the first direction. This in turn causes the paired tendon to travel in a second direction opposite to the first direction and thereby pull a second slider attached to it in the second direction. Hence, pairs of the plurality of sliders may work antagonistically to one another by actuating antagonistic pairs of tendons.

In embodiments of the invention each channel will be associated with a single slider only. This means that in embodiments of the invention comprising a plurality of sliders, each slider is moveable within its own channel.

The channels may be linear although in other embodiments of the invention they may be curved.

In such embodiments of the invention, each slider may comprise a body portion comprising an alignment portion, the alignment portion being adapted to position the tendon receiving portion of the respective slider such that it is aligned with the shaft aperture. Accordingly a plurality of tendons may extend along the shaft of the driver module and each tendon may exit the shaft and be received by a respective tendon receiving portion without any of the tendons having to be significantly diverted from the axis of the shaft.

This means that it is not necessary to use extra components such as pulleys in order to appropriately route a tendon exiting from the shaft aperture in order for that tendon to reach its respective tendon receiving portion.

In embodiments of the invention, the body portion of each slider comprises a head portion positionable such that the head portion of that slider is abuttable with the head portion of at least one other adjacent slider.

In such embodiments of the invention, the tendon receiving portions of each of the sliders abut with or are close to adjacent sliders such that tendons exiting from a shaft aperture may be readily received by a respective tendon receiving portion without having to be diverted in order to reach that tendon receiving portion. Further, the sliders may lean against one another such that each slider is supported the other sliders adjacent to it. This may reduce the effect of any forces acting on a single slider, in use, and improve the durability of the sliders against bending or breaking.

In embodiments of the invention, the driver module may further comprise an attachment interface and a locking mechanism, the attachment interface being engageable with a mating interface, the locking mechanism being adapted to lock and unlock the attachment interface in engagement with the mating interface.

In such embodiments of the invention, the mating interface may be a mating interface forming part of a motor module for actuating the sliders of the driver module, or a barrier for providing a sterility barrier between the driver module and a motor module.

In embodiments of the invention, the locking mechanism comprises a latch comprising a wedge, which latch is moveable between a first position in which the wedge is received within the attachment interface, and a second position in which the wedge protrudes from the attachment interface, wherein the latch is biased towards the second position.

In such embodiments of the invention, when the attachment interface is engaged with a mating interface, the wedge may be engageable with a latch socket forming part of a barrier or motor module, for example. Engagement of the wedge with the latch socket may lock the attachment interface into engagement with the mating interface, thereby locking the driver module in engagement with the barrier or motor module, for example.

In embodiments of the invention, the drive module may further comprise a gear assembly, the gear assembly comprising a gear slider moveable in a linear direction, a gear wheel rotatable about a gear axis and a geared shaft rotatable about a shaft axis; the gear slider being engageable with the gear wheel, and the gear wheel being engageable with the geared shaft such that linear movement of the linear slider drives rotation of the gear wheel about the gear axis whereby the geared shaft rotates about the shaft axis.

In such embodiments of the invention, the geared shaft may be attachable to, or form part of, a shaft of a surgical instrument. The gear assembly may therefore be used to translate linear movement of an actuator forming part of a motor module, for example, to rotational movement of the shaft of the surgical instrument.

According to a second aspect of the present invention there is provided a surgical instrument comprising a driver module according to embodiments of the invention comprising a single slider, and further comprising a tendon, receivable at a first end by the tendon receiving portion of the slider;.

According to a further aspect of the present invention there is provided a surgical instrument comprising a driver module according embodiments of the invention comprising a plurality of sliders and further comprising a plurality of tendons, each of the tendons being receivable at a first end by a tendon receiving portion of one of the plurality of sliders;.

In embodiments of the invention the surgical instrument further comprises a barrier having a first side and a second side, the first side being engageable with the driver module and the second side being engageable with the motor module.

In such embodiments, prior to the barrier being provided to the surgical instrument for use, the barrier is sterile along all sides. However, in use, the second side is engaged with the motor module, which is non-sterile, therefore the second side of the barrier becomes non-sterile while the first side remains sterile as it is protected by the barrier and does not come into contact with non-sterile components. This means that the motor-module, which may be expensive, does not require sterilising after each use. This may be useful because the motor module may comprise various electrical components that could be damaged during sterilisation.

In embodiments of the invention the barrier comprises a plurality of barrier sliders, each of which barrier sliders comprises a first portion and a second portion, the first portion being engageable with one of the plurality of sliders of the driver module and the second portion being engageable with one of the plurality of actuators of the motor module.

In such embodiments, prior to the barrier being provided to the surgical instrument for use, all portions of the plurality of barrier sliders are sterile. In use, the second portion of each barrier slider may become non-sterile following engagement with one of the plurality of actuators of the motor module which is non-sterile. However, the first portion remains sterile as it is protected by the barrier. This again means that the motor-module does not require sterilising after each use. This may be useful because the motor module may comprise various electrical components that could be damaged during sterilisation.

In embodiments of the invention the mating interface is a barrier interface forming part of the first side of the barrier and comprises a latch socket in which the wedge is receivable when the attachment interface is engaged with the barrier interface, and the wedge is adapted such that, when the attachment interface is engaged with the barrier interface, the bias of the latch towards the second position causes the driver module to be biased towards a position in which the plurality of sliders engage with the plurality of barrier sliders and the plurality of tendons are tensioned.

In such embodiments of the invention, the wedge may be adapted, with a tapered shape for example, such that as it moves towards the second position (to which it is biased) it causes the attachment interface to move over the barrier interface until each of the plurality of sliders contacts a respective barrier slider. This may bring the tendon, attached to each slider, under tension and reduce backlash in the surgical instrument. Accordingly, the wedge may be adapted to cause optimal engagement of the attachment interface with the barrier interface.

The invention will now be described by way of example only with reference to the accompanying drawings in which:.

Referring initially to <FIG>, a slider according to an embodiment of the first aspect of the invention is designated generally by the reference numeral <NUM>. The slider <NUM> comprises a base portion <NUM> and a tendon receiving portion <NUM> that is spaced apart from the base portion <NUM>. The base portion <NUM> comprises a first end <NUM>, a second end <NUM>, a first side <NUM> and a second side <NUM>.

The slider further comprises a body portion <NUM> extending from the base portion <NUM> to the tendon receiving portion <NUM>, and a drive portion <NUM>. The base portion <NUM> is positioned between the body portion <NUM> and the drive portion <NUM>. The body portion <NUM> comprises an alignment portion <NUM> and a head portion <NUM>.

Referring now to <FIG>, a driver module according to another embodiment of the first aspect of the invention is defined generally by the reference numeral <NUM>. The driver module <NUM> comprises a slider <NUM>, and a slider receiving portion <NUM>. The slider <NUM> is similar to and interchangeable with the slider <NUM> shown in <FIG>. All of the features of slider <NUM> correspond to similar or identical features in slider <NUM>, therefore for ease of reference the reference numerals used for slider <NUM> are also applicable to slider <NUM>.

The slider receiving portion <NUM> comprises a first end <NUM> and a second end <NUM>. The slider receiving portion <NUM> is engageable with the base portion <NUM> of the slider <NUM> such that the slider <NUM> is movably attachable to the slider receiving portion <NUM>.

The driver module <NUM> further comprises a guide tray <NUM> comprising the slider receiving portion <NUM>. The slider receiving portion <NUM> comprises a plurality of channels <NUM>, each extending along the length of the slide receiving portion. In this embodiment of the invention, however, one channel <NUM> only is required to engage with the slider <NUM>. The channel <NUM> is adapted to receive the base portion <NUM> of the slider <NUM> such that it is moveable along the channel <NUM>. In some embodiments of the invention the slider receiving portion <NUM> may comprise a single channel <NUM> only. In this embodiment of the invention the channel <NUM> is linear, although in other embodiments of the invention it may follow a different trajectory.

Referring now to <FIG>, a driver module according to a further embodiment of the first aspect of the invention is defined generally by the reference numeral <NUM>. The driver module <NUM> comprises the slider <NUM>, and a slider receiving portion <NUM>. The slider receiving portion <NUM> comprises a first end <NUM> and a second end <NUM>. The slider receiving portion <NUM> is engageable with the base portion <NUM> of the slider <NUM> such that the slider <NUM> is movably attachable to the slider receiving portion <NUM>.

The driver module <NUM> further comprises a guide tray <NUM>, the guide tray <NUM> comprising the slider receiving portion <NUM>. The slider receiving portion <NUM> comprises a plurality of channels <NUM>, similarly to the embodiment of the invention shown in <FIG>.

The driver module <NUM> further comprises a first roller <NUM> and a second roller <NUM> that are spaced apart from one another. Both the first roller <NUM> and the second roller <NUM> are engageable with the base portion <NUM> of the slider <NUM>. The first roller is positioned to engage the slider <NUM> from the first side <NUM> of the base potion <NUM> and close to the first end <NUM>. The second roller is positioned to engage with the slider <NUM> from the second side <NUM> of the base portion <NUM> and close to the second end <NUM>.

The respective positions of the first roller <NUM> and the second roller <NUM> mean that, in use, the slider <NUM> remains engaged within the slider receiving portion <NUM>. The first and second rollers <NUM>, <NUM> are rotatable about their respective axes to facilitate the movement of the slider <NUM> toward and away from the first end <NUM> of the slider receiving portion <NUM>.

In other words, linear movement of the slider <NUM> is translated to rotational movement of the first and second rollers <NUM>, <NUM>. Where the linear movement of the slider may otherwise have resulted in a sliding friction between the slider <NUM> and any contacting surfaces, in this embodiment of the invention at least some of the contact pressure that the slider exhibits in use is transferred from the slider <NUM> to the first and second rollers <NUM>, <NUM>. The first and second rollers <NUM>, <NUM> may be configured to experience minimal friction when rotating about their respective axes. Therefore when, in use, the slider <NUM> is moved toward or away from the first end <NUM>, the movement is facilitated by the first and second rollers <NUM>, <NUM> with minimal friction.

Referring now to <FIG>, a driver module according to another embodiment of the first aspect of the invention is defined generally by the reference numeral <NUM>. The driver module <NUM> comprises a plurality of sliders <NUM> and a slider receiving portion <NUM>. The slider receiving portion <NUM> is engageable with the base portion <NUM> of each of the plurality of sliders <NUM> such that each slider <NUM> is movably attachable to the slider receiving portion <NUM>.

The driver module <NUM> further comprises a guide tray <NUM>, the guide tray <NUM> comprising the slider receiving portion <NUM>. The slider receiving portion <NUM> comprises a plurality of linear channels <NUM> that are spaced evenly across the guide tray <NUM>. Each of the plurality of linear channels <NUM> is adapted to receive the base portion <NUM> of a corresponding slider <NUM> such that the base portion <NUM> of each slider <NUM> is moveable along the corresponding linear channel <NUM>.

The alignment portion <NUM> of each of the plurality of sliders <NUM> is adapted to place the tendon receiving portions <NUM> of each slider <NUM> into close alignment with one another. In order to achieve this, the alignment portion <NUM> of each slider <NUM> is configured depending on the position of the corresponding channel <NUM> with which the slider <NUM> is engageable. As a result, a first slider 4a has an alignment portion 24a which has a different size and or shape to an alignment portion 24b of a second slider 4b. There is variance in the shape of the alignment portions <NUM> across each of the plurality of sliders <NUM>. In embodiments of the invention, the shape of the alignment portions <NUM> may vary due to changes in their length, angle, orientation or any combination thereof. In other embodiments of the invention the shape of the alignment portions <NUM> may vary due to substantially differing geometries. In other embodiments of the invention the shape of the alignment portions <NUM> may not vary.

The alignment portion <NUM> of each slider <NUM> is further adapted to cause the head portion <NUM> of each slider to be positioned in close proximity with, or in abutment with the head portion <NUM> of at least one other adjacent slider <NUM> of the plurality of sliders.

In the embodiment shown in <FIG> adjacent head portions <NUM> abut with one another. The head portion <NUM> of each slider <NUM> is adapted to slideably abut with the head portion <NUM> of at least one adjacent slider <NUM> of the plurality of sliders <NUM>. The sliders <NUM> are thus able to slide past one another whilst also abutting at least one adjacent slider. The abutment of the head portions <NUM> against one another provides the sliders <NUM> with support from the other sliders <NUM>. This support is substantially normal to the direction of the plurality of linear channels <NUM> and normal to the base portion <NUM> of each of the plurality of sliders <NUM>. The provision of support in this direction protects the sliders <NUM> from twisting or bending in response to forces that may be transmitted during actuation of the drive portion <NUM> of each of the plurality of sliders <NUM>.

Referring now to <FIG>, a driver module according to another embodiment of the first aspect of the invention is defined generally by the reference numeral <NUM>. The driver module <NUM> comprises all features of the driver module <NUM> shown in <FIG> and further comprises a plurality of tendons <NUM>, a shaft <NUM>, a shaft receiving portion <NUM>, an attachment interface <NUM>, a locking mechanism <NUM> and a gear assembly <NUM>.

The gear assembly comprises a geared shaft <NUM>. The shaft receiving portion <NUM> is adapted to receive the geared shaft <NUM> such that the geared shaft <NUM> is rotatably attached to the shaft receiving portion <NUM>. The geared shaft is in turn adapted to receive the shaft <NUM> such that the shaft <NUM> is non-rotatably attached to the geared shaft <NUM>.

A plurality of tendons <NUM> extend through the shaft <NUM>, geared shaft <NUM> and shaft receiving portion <NUM>. Each of the tendons <NUM> is received at a first end by a corresponding tendon receiving portion <NUM>.

The alignment portion <NUM> of each of the plurality of sliders <NUM> is adapted to position the tendon receiving portions <NUM> of the sliders <NUM> into close alignment with one another as described above in relation to <FIG>. In this embodiment, this also results in the tendon receiving portions <NUM> being in close axial alignment with the shaft receiving portion. As a result, the tendons <NUM>, which extend through the shaft <NUM>, remain in approximate alignment as they extend out of the shaft receiving portion <NUM> towards a corresponding tendon receiving portion <NUM>.

The maintenance of the plurality of tendons <NUM> substantially in alignment with the shaft <NUM>, obviates the need to divert the tendons <NUM> by use of pulleys or any other means in order to reach a tendon receiving portion. This in turn reduces the number of parts required in the driver module <NUM> and also reduces the potential for wear of the plurality of tendons <NUM>.

The attachment interface <NUM> is engageable with a barrier which is in turn engageable with a motor module. The locking mechanism <NUM> is adapted to lock and unlock the attachment interface <NUM> into and out of engagement with the barrier respectively.

Referring now to <FIG>, the gear assembly shown in <FIG> is shown in more detail. The gear assembly comprises a gear slider <NUM> and a gear wheel <NUM>. The gear slider <NUM> is moveable in a linear direction, the gear wheel <NUM> is rotatable about its central axis and the geared shaft <NUM> is rotatable about its central axis which it shares with the shaft <NUM> shown in <FIG>. The gear slider <NUM> is engageable with the gear wheel <NUM> which is in turn engageable with the geared shaft <NUM>. Linear movement of the linear slider <NUM> drives rotation of the gear wheel <NUM> about its axis which in turn drives rotation of the geared shaft <NUM> about its axis. When the shaft <NUM>, shown in <FIG>, is non-rotatably attached to the geared shaft <NUM>, linear movement of the gear slider <NUM> drives rotation of the geared shaft <NUM> about its axis which in turn rotates the shaft <NUM>.

Referring now to <FIG>, a driver module according to another embodiment of the first aspect of the invention is defined generally by the reference numeral <NUM>. A cross-sectional view of the driver module <NUM> is shown that comprises a plurality of sliders <NUM>, a pre-tensioning actuator <NUM> and a disengagement device <NUM>. The pre-tensioning actuator comprises a biasing element <NUM> and a cross plate <NUM>. The disengagement device <NUM> comprises a lever pin <NUM> about which the disengagement device is rotatable. The lever pin may be attached to a guide tray, thereby anchoring the disengagement device in the driver module <NUM>. (The guide tray is not shown here but may be considered as equivalent to the guide trays <NUM>, <NUM>, and <NUM> shown in <FIG>, <FIG>, <FIG> and <FIG>).

Referring now to <FIG>, a cross-section of the driver module <NUM> is shown. The pre-tensioning actuator <NUM> is shown in a first position where it is engaged with the plurality of sliders <NUM> via the cross plate <NUM>.

The biasing element <NUM>, which in this embodiment of the invention takes the form of a spring. The biasing element biases the pre-tensioning actuator toward the second end <NUM> of the slider receiving portion (not shown). In moving toward the second end <NUM> of the slider receiving portion <NUM>, the pre-tensioning actuator <NUM> comes into contact with, and engages the plurality of sliders <NUM>. The pre-tensioning actuator <NUM> continues to move toward the second end <NUM> of the slider receiving portion and in doing so provides movement of the plurality of sliders <NUM> in the same direction. This continues until a plurality of tendons are in complete tension and the plurality of sliders <NUM> may move no further. (The plurality of tendons is not shown here but may be considered as equivalent to the plurality of sliders <NUM> shown in <FIG>. ) Hence the pre-tensioning actuator <NUM> is provided to maintain the tension of the plurality tendons, which helps to keep the plurality of tendons <NUM> in good condition.

Referring now to <FIG>, a cross-section of the driver module <NUM> is shown similarly to <FIG>. The pre-tensioning actuator <NUM> is shown in a second position where is the cross plate <NUM> is disengaged with the plurality of sliders <NUM>.

The pre-tensioning device <NUM> may be moved to the second position by rotating the disengagement device <NUM> about the lever pin <NUM> so that it transitions from the position shown in <FIG> to that shown in <FIG>. The rotation of the disengagement device <NUM> acts against the biasing element <NUM>, in this embodiment by causing compression of the spring. When in the second position, the pre-tensioning device <NUM>, specifically the cross plate <NUM>, is disengaged from the plurality of sliders <NUM>. This provides the plurality of sliders with the ability to move freely in the respective slider channels (not shown), either toward the first end <NUM> or second end <NUM> of the slider receiving portion. In this embodiment of the invention the plurality of sliders <NUM> are able to move <NUM> in either direction when the pre-tensioning actuator <NUM> is disengaged.

In use, the driver module <NUM> is engaged with a barrier via an attachment interface <NUM>. The disengagement device <NUM> in the position shown in <FIG> protrudes from the surface of the attachment interface <NUM> so that, when the driver module <NUM> is engaged with the barrier, the disengagement device <NUM> is caused to rotate about the lever pin <NUM> toward the position shown in <FIG>. This rotation of the disengagement device <NUM> results in movement of the pre-tensioning actuator <NUM> from the first position to the second position, against the bias of the biasing element <NUM>.

This means that, when the driver module <NUM> is engaged with the barrier, ready for use, the disengagement device <NUM> automatically disengages the pre-tensioning actuator <NUM> from the plurality of sliders <NUM> so that the sliders <NUM> are free to move without pressure being exerted against them by the biasing element <NUM>.

Referring now to <FIG>, a surgical instrument according to an embodiment of the second aspect of the invention is defined generally by the reference numeral <NUM>. The surgical instrument comprises a driver module <NUM>, a shaft <NUM> and a barrier <NUM>.

The driver module <NUM> comprises an outer casing <NUM>, a shaft receiving portion <NUM>, an attachment interface <NUM>, a locking mechanism <NUM> and a grip <NUM>, while the barrier <NUM> comprise a barrier interface <NUM>. The driver module <NUM> is positioned so that the attachment interface <NUM> is ready to be engaged with the barrier interface <NUM> of the barrier. The barrier interface <NUM> is an example of a mating interface with which the attachment interface <NUM> may be engaged. The attachment interface <NUM> may be engaged with any suitable mating interface, another example being a mating interface forming part of a motor module for actuating the sliders of the driver module <NUM>.

The barrier interface <NUM> comprises a pair of barrier grooves <NUM> that extend along the length of the barrier interface <NUM> and the attachment interface <NUM> comprises a pair of attachment ridges <NUM> that extend along the length of the attachment interface <NUM> and that are receivable by the barrier grooves <NUM>. In use, the attachment interface <NUM> may be engaged with the barrier interface <NUM> by gripping the grip <NUM> and simply sliding the attachment interface <NUM> in contact with the barrier interface <NUM> such that the attachment ridges <NUM> are fully received by the barrier grooves <NUM>.

The shaft <NUM> is engaged with the shaft receiving portion <NUM>.

Referring now to <FIG>, the driver module <NUM> shown in <FIG> is illustrated with the outer casing <NUM> and the attachment interface <NUM> removed in order to reveal internal elements of the locking mechanism <NUM>.

In this embodiment of the invention, the locking mechanism <NUM> comprises a pair of latches <NUM>, a pair of springs <NUM> and a release handle <NUM>. The pair of latches <NUM> are spaced apart from one another and extend normally from the release handle <NUM>, parallel to one another. Each latch <NUM> comprises a piston <NUM> at a proximal end and a wedge <NUM> at a distal end. Further, each latch <NUM> is coupled to the release handle <NUM> at its proximal end, wherein the piston <NUM> extends from the release handle <NUM> shaped as a cylindrical bar which is surrounded by a respective one of the springs <NUM>. The wedge <NUM>, extends further from the piston <NUM> with a wedge-shape that tapers toward a distal end of the latch <NUM>.

Referring now to <FIG>, a cross-sectional view of the driver module <NUM> and barrier <NUM> shown in <FIG> is provided wherein the driver module <NUM> is engaged with the barrier <NUM>. Here only a single latch <NUM> and respective spring <NUM> are visible though the second latch and spring are still present. Description of the latch <NUM> and spring <NUM> shown in <FIG> set out below therefore also applies to the latch <NUM> and spring <NUM> that are not shown.

The latch <NUM> and respective spring <NUM> are encased in the attachment interface <NUM>. A first end of the spring <NUM> is attached to the latch <NUM> while a second end is attached to the attachment interface <NUM>. Movement of the latch <NUM> relative to the attachment interface in the direction of its proximal end causes compression of the spring <NUM>, such that the wedge <NUM> of the latch <NUM> is biased by the spring <NUM> toward protruding from the attachment interface <NUM>.

When engaging the driver module <NUM> with the barrier <NUM>, the attachment interface <NUM> is slid over the barrier interface <NUM> such that the attachment ridges <NUM> are received by the barrier groove <NUM> as described above. However, the wedge <NUM> protrudes from the attachment interface and abuts against a leading edge <NUM> of the barrier interface <NUM> when the attachment interface <NUM> is slid over the barrier interface <NUM>. Hence full receival of the attachment ridges <NUM> into the barrier grooves is obstructed.

The wedge <NUM> and the leading edge <NUM> are adapted such that the leading edge <NUM> and an abutting surface of the wedge <NUM> are at a complimentary angle to one another. Once the wedge <NUM> is in abutment with the leading edge <NUM>, further linear sliding movement of the attachment interface relative to the barrier interface <NUM> causes the latch to be forced in the direction of its proximal end, normal to the sliding movement and against the bias of the spring <NUM>.

As is shown in <FIG>, the barrier comprises a latch socket <NUM> adapted to receive the wedge <NUM>. Therefore, when the attachment interface <NUM> is slid further over the barrier interface <NUM> so that the tip of the wedge <NUM> has passed the leading edge <NUM>, the bias of the compressed spring <NUM> causes the wedge <NUM> to move so that it again protrudes from the attachment interface <NUM> and thereby extends into the latch socket <NUM>. The walls of the latch socket <NUM> are adapted so that, as the wedge <NUM> extends into the latch socket <NUM> due to the bias produced by the spring <NUM>, the attachment interface <NUM> is pushed further over the barrier interface <NUM>. The attachment interface <NUM> may continue to slide over the barrier interface <NUM> in this manner, until each of the plurality of sliders <NUM> is touching a respective barrier slider (referred to in further detail with respect to <FIG>).

The movement of the driver module <NUM> into engagement with the barrier <NUM> as set out above, and particularly movement of the sliders <NUM> into engagement with the barrier sliders, may result in stretching tendons attached to the sliders <NUM> (via the tendon receiving portions <NUM>) until the tensile force in the tendons is balanced with the force introduced by the spring <NUM>. The resulting tensile force in the tendons may increase the robustness of the surgical instrument <NUM> (particularly an articulated module such as the articulated module <NUM> shown in <FIG>) and reduce backlash in the surgical instrument <NUM> when in use. The wedge <NUM> and the strength of the spring <NUM> may be designed to achieve optimal tension in the tendons while risk of the wedge <NUM> dislodging is prevented when an external force tries to push the driver module <NUM> away from the barrier <NUM>.

In order to disengage the driver module <NUM> from the barrier <NUM>, the release handle <NUM> may be pulled away from the driver module <NUM>, thereby moving the pair of latches <NUM> against the bias of their respective springs <NUM> and withdrawing each wedge <NUM> from its respective latch socket <NUM>. The driver module <NUM> may then be slid away from the barrier <NUM> in the reverse direction of that with which it was originally engaged.

Referring now to <FIG>, a driver module <NUM> according to another embodiment of the first aspect of the invention is similar to the driver module <NUM> shown in <FIG> except that it comprises a locking mechanism <NUM> which differs to the locking mechanism <NUM>. Firstly, the locking mechanism <NUM> comprises a release bridge <NUM> rather than the release handle <NUM>. Further, the locking mechanism <NUM> comprises a moveable pulling ring <NUM> rather than the static grip <NUM>. Extending from the pulling ring <NUM>, under the release bridge <NUM> and into the outer casing (which is transparent in <FIG>) is a bridge actuator <NUM> which expands in thickness as it extends away from the pulling ring <NUM>. The bridge actuator comprises a sloped surface <NUM> which is engageable with the release bridge <NUM> and may cause the release bridge <NUM> to move relative to the remainder of the driver module <NUM> depending on the position of the bridge actuator <NUM>. (The other features of the driver module <NUM>, such as the plurality of sliders <NUM> and the shaft <NUM>, are identical to the driver module <NUM> shown in <FIG>.

In use, rather than pulling the release handle <NUM> to retract the latch <NUM> (shown in <FIG> and <FIG>), a user may instead pull the pulling ring <NUM> away from the driver module <NUM> to cause the bridge actuator <NUM> to move in the same direction as the pulling ring <NUM>. The sloped surface <NUM> may thereby be caused to push against the release bridge <NUM> and, further, cause the release bridge <NUM> to slide over the bridge actuator <NUM>, hence raising the release bridge <NUM> away from the driver module <NUM>. As the release bridge <NUM> is raised, the latch <NUM> may be retracted into the driver module <NUM> and the driver module <NUM> may be disengaged from a barrier (such as the barrier <NUM> shown in <FIG> and <FIG>), for example.

The pulling ring <NUM> and bridge actuator <NUM> may be moveable parallel to the shaft <NUM> and the attachment interface <NUM>. Therefore, a user may advantageously be able to disengage the driver module <NUM> from a barrier <NUM> with a single motion in a single direction, rather than needing to pull a release handle <NUM> in one direction while pulling the driver module <NUM> in a different direction.

Referring now to <FIG>, a barrier according to another embodiment of the second aspect of the invention is defined generally by the reference numeral <NUM>. The barrier comprises a first side <NUM> and a second side <NUM>. The second side is configured to engage and cover non-sterile items such as a motor module. The first side is configured to engage with sterile items such as the driver module <NUM> shown in <FIG> and protect them from non-sterile items, thus maintaining their sterility. Hence the barrier <NUM> is provided to form a physical barrier between non-sterile items and sterile items, such as a driver module according to the first aspect of the invention, to ensure the sterile items remain sterile.

Referring now to <FIG>, an expanded view of the barrier <NUM>, shown in <FIG>, is provided. The barrier <NUM> further comprises a plurality of barrier sliders <NUM>, wherein each of the plurality of barrier sliders <NUM> comprises a first portion <NUM> and a second portion <NUM>. Each first portion <NUM> is engageable with a corresponding one of a plurality of sliders <NUM>, <NUM>, <NUM> that may be provided by a driver module <NUM>, <NUM>, <NUM> shown in <FIG>, <FIG> and <FIG> respectively. Each second portion <NUM> is engageable with one of a plurality of actuators provided by a motor module.

Referring now to <FIG>, a surgical instrument according to an embodiment of the second aspect of the invention is defined generally by the reference numeral <NUM>. The surgical instrument <NUM> comprises a driver module <NUM> and shaft <NUM> similar to, and interchangeable with, the driver modules <NUM>, <NUM> and shafts <NUM>,<NUM> shown in <FIG> and <FIG>. The surgical instrument <NUM> further comprises an articulation module <NUM> and an end effector <NUM>. The articulation module <NUM> is coupled to the shaft <NUM>, whereby the shaft <NUM> is positioned between the driver module <NUM> and the articulation module <NUM>. The end effector <NUM> is coupled to the articulation module <NUM>, whereby the articulation module <NUM> is positioned between the shaft <NUM> and the end effector <NUM>.

Referring now to <FIG>, a surgical instrument according to a further embodiment of the second aspect of the invention is defined generally by the reference numeral <NUM>. The surgical instrument comprises a pair of driver modules 802a, 802b and shafts 803a, 803b similar to those shown in <FIG> and <FIG>. The surgical instrument <NUM> further comprises a pair of motor modules 807a, 807b and a barrier <NUM>, similar to that shown in <FIG>, which comprises a first side <NUM> and a second side <NUM>. The pair of driver modules 802a, 802b are both engaged with the first side <NUM> of the barrier <NUM> and the pair of motor modules are both engaged to the second side <NUM> of the barrier <NUM>.

Claim 1:
A driver module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for actuating a tendon (<NUM>, <NUM>), the driver module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising:
a slider (<NUM>, <NUM>, <NUM>) comprising a base portion (<NUM>), a tendon receiving portion (<NUM>) and a body portion (<NUM>), the tendon receiving portion (<NUM>) being spaced apart from the base portion (<NUM>) and the body portion (<NUM>) extends from the base portion (<NUM>) to the tendon receiving portion (<NUM>), the module further comprising a slider receiving portion (<NUM>, <NUM>, <NUM>) having a first end (<NUM>, <NUM>) and a second end (<NUM>, <NUM>) and engageable with the base portion (<NUM>) of the slider (<NUM>, <NUM>, <NUM>) such that the slider (<NUM>, <NUM>, <NUM>) is attachable to and movable within the slider receiving portion (<NUM>, <NUM>, <NUM>),
characterised in that the driver module further comprises a pre-tensioning actuator (<NUM>), the pre-tensioning actuator (<NUM>) being moveable between a first position and a second position, wherein in the first position the pre-tensioning actuator (<NUM>) is engaged with the slider (<NUM>) such that the slider (<NUM>) is positioned toward the second end (<NUM>) of the slider receiving portion (<NUM>), and in the second position the pre-tensioning actuator (<NUM>) is disengaged from the slider (<NUM>); the driver module (<NUM>) further comprises a bias (<NUM>), biasing the pre-tensioning actuator (<NUM>) towards the first position.