SURGICAL DEVICE AND LOCKING COMPONENT THEREFOR

Abstract

A locking component for a surgical device is disclosed, which is configured to prevent deployment of a blade when a first jaw member and a second jaw member of the surgical device are disposed in an open position and to permit deployment of the blade when the first and second jaw members are disposed in a closed position. The locking component includes a latch member, configured to prevent deployment of the blade by a mechanical interaction therewith when the latch member is in a first position. The locking component also includes a compliant body, connected to and disposed around the latch member, configured to bias the latch member to its first position. A surgical device incorporating the locking component and a method of operating the same is also disclosed.

Claims

1. A locking component for a surgical device configured to prevent deployment of a blade when a first jaw member and a second jaw member of the surgical device are disposed in an open position and to permit deployment of the blade when the first and second jaw members are disposed in a closed position, the locking component comprising: a latch member, configured to prevent deployment of the blade by a mechanical interaction therewith when the latch member is in a first position; and a compliant body, connected to and disposed around the latch member, configured to bias the latch member to its first position.

2. The locking component according to claim 1, wherein the compliant body is a closed loop.

3. The locking component according to claim 1, wherein the compliant body is parallel to a first plane and is configured to exert a biasing force in a direction parallel to the first plane.

4. The locking component according to claim 3, wherein the latch member comprises a protrusion from the locking component in a direction perpendicular to the first plane.

5. The locking component according to claim 3, further comprising a rib, configured to be slideably received by the surgical device so as to constrain movement of the latch member in the first plane.

6. The locking component according to claim 5, wherein the latch member and the compliant body are connected by the rib.

7. The locking component according to claim 5, wherein the latch member comprises a protrusion from the rib.

8. The locking component according to claim 1, wherein the latch member and the compliant body comprise an integral component.

9. The locking component according to claim 1, wherein the latch member and the compliant body comprise a single moulding.

10. The locking component according to claim 1, wherein a cross section of at least a portion of the compliant body is rectangular.

11. The locking component according to claim 1, wherein the compliant body comprises first and second straight portions, the straight portions being joined together by first and second arc portions.

12. The locking component according to claim 11, wherein the first arc portion is configured to join together first ends of the first and second straight portions, and the second arc portion is configured to join together second ends of the first and second straight portions.

13. The locking component according to claim 11, wherein the first and second straight portions are parallel.

14. The locking component according to claim 1, wherein the compliant body is stadium-shaped.

15. The locking component according to claim 1, further comprising an arm, provided in fixed relation to the latch member and configured to transfer a force to the latch member to thereby move it away from the first position.

16. The locking component according to claim 15, wherein the latch member, the compliant body and the arm are comprised in a single integral component.

17. A surgical device comprising: a hand-piece, first and second jaw members extending from the hand-piece, configured to be open and closed in response to manipulation of the hand-piece, a blade assembly comprising a blade and a trigger mechanism for deploying the blade towards the first and second jaw members, and a locking component, comprising a first latch member, the first latch member being configured to mechanically interact with a second latch member comprised in the blade when the first latch member is in a first position, in order to prevent deployment of the blade, wherein the locking component further comprises a compliant body, configured to bias the latch member to its first position.

18. The surgical device according to claim 17, wherein the first latch member and the compliant body are comprised in a single moulded component.

19. The surgical device according to claim 17, wherein the first and second jaw members are provided with respective opposing electrically conductive plates on the inner opposing surfaces thereof, the electrically conductive plates being connectable in use via respective connections to an RF electrosurgical generator so as to receive, in use, an RF electrosurgical signal.

20. A method of operating a surgical device having a hand-piece, opposing jaw members extending from the hand-piece, a blade and a locking component, the locking component comprising a compliant body, lying parallel to a first plane, and a latch member configured to mechanically interact with the blade to prevent deployment of the blade when the latch member is in a first position, the method comprising the steps of: manipulating the hand-piece to close the opposing jaw members, wherein closing the jaw members exerts a force on the latch member parallel to the first plane, such that the latch member is moved away from the first position so as to disengage the blade, and activating a trigger mechanism to deploy the blade.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Further features and advantages of the present disclosure will become apparent from the following description of embodiments thereof, presented by way of example only, and by reference to the drawings, in which:

[0046] FIG. 1 is a schematic diagram of an electrosurgical system according to an embodiment;

[0047] FIG. 2 is a side view of a surgical device according to an embodiment;

[0048] FIG. 3A is a perspective view of a first side of a locking component according to an embodiment;

[0049] FIG. 3B is a perspective view of a second side of the locking component according to an embodiment;

[0050] FIG. 4 is a perspective view of a first side of part of a surgical device having a locking component according to an embodiment;

[0051] FIG. 5 is a side view of a second side of part of a surgical device having a locking component according to an embodiment.

DETAILED DESCRIPTION

[0052] A surgical device and a locking device therefor is described herein in the context of an electrosurgical system for performing procedures such as clamping, cutting and sealing of tissues using an end effector. The system includes an electrosurgical generator capable of providing a radiofrequency (RF) output, which may be controlled by various user inputs such as push buttons and switches on the electrosurgical generator and/or surgical device itself. A hand-piece of the surgical device is connected to the generator by a connection cord capable of transmitting power and RF signals thereto. The hand-piece provides a means with which a practitioner may manipulate the end effector. The surgical device is not limited to use within an electrosurgical system but may also be employed in a device without any electrosurgical capabilities, such as those used for the clamping and cutting of vessels.

[0053] The present disclosure is particularly applicable to scissor-action devices, such as those comprising a pair of jaw members which can be used to grip tissue or vessels during surgery. The hand-piece can be manipulated by a user to open and close the jaws. In order to cut tissue, a blade is provided which can be deployed, by a trigger mechanism, through an opening between the jaw members. A locking component of the device prevents the blade from being deployed when the jaw members are open. The locking component includes a compliant body that can flex and deform but will return to its original shape when released. The compliant body is a closed loop of material and lies within a first plane. A latch member, for example a pin, is fixed to the compliant body and extends in a direction that is non-parallel to the plane of the compliant body. When the locking component is installed in a surgical device, the latch member engages a portion of the cutting blade to prevent the blade from being deployed. When the jaws are closed, a force is transferred to the latch member to move it in a direction parallel to the plane of the compliant body. This releases the latch member from the blade and allows the blade to be deployed. Once the jaws are opened again, the compliant body returns to its original position such that the latch member re-engages the blade and prevents deployment thereof.

[0054] Referring to the drawings, FIG. 1 shows electrosurgical apparatus including an electrosurgical generator 1 having an output socket 2 providing a radio frequency (RF) output, via a connection cord 4, for a surgical device 100. Activation of the generator 1 may be performed from the device 100 via a hand-switch (not shown) on the device 100, or by means of a footswitch unit 5 connected separately to the rear of the generator 1 by a footswitch connection cord 6. In the illustrated arrangement, the footswitch unit 5 has two footswitches 5a and 5b for selecting between different modes of the device 100. The generator front panel has push buttons 7a, 7b for respectively setting the power used for sealing vessels, which is indicated in a display 8. Push buttons 9 are provided as an alternative means for selection between the modes of operation.

[0055] FIG. 2 shows the surgical device 100 that forms the basis of an embodiment of the present disclosure. The surgical device 100 comprises a hand-piece 120 and an elongate shaft 101. The elongate shaft 101 extends along a substantially longitudinal axis of the surgical device 100. The elongate shaft 101 is connected at a proximal end to the hand-piece 120 and is connected to an end effector 110 at a distal end. The hand-piece 120 comprises a handle portion 121 and a lever 122, shown in FIG. 2 in the open position. The lever 122 is pivotally connected to the handle portion 121 such that a user may move the hand-piece 120 to a closed position in which the lever 122 is moved towards the handle portion 121. The hand-piece 120 is biased towards the open position by a biasing means (not shown) and configured such that when a user releases the lever 121, it is returned to the open position away from the handle portion 121.

[0056] The surgical device 100 further comprises a blade (not shown in FIG. 1) for cutting tissue and vessels. The blade comprises a first end located within the handle portion 121 and extends along the elongate shaft 101 up to a second end located towards the end effector 110. Therefore, the blade has a longitudinal axis parallel to the longitudinal axis of the elongate shaft 101. The blade comprises a cutting portion (not shown) at the second end which has an edge suitable for cutting vessels and tissue. The surgical device further comprises a trigger mechanism (not shown) configured to deploy the blade such that the cutting portion at the second end extends beyond the elongate shaft 101 to protrude out of the end effector 110. Any conventional trigger mechanism that is able to deploy the blade with sufficient force to cut tissue may be employed. The trigger mechanism is activated by a trigger 123. In FIG. 2, the trigger is shown to extend from the lever 122, but the trigger 123 may be fixed to any part of the hand-piece 120 that permits operation when in use by a practitioner. The trigger mechanism may be configured such that pulling the trigger 123 deploys the blade and then immediately returns the blade to its resting position.

[0057] The end effector 101 comprises a first jaw member 111 and a second jaw member 112. The first and second jaw members 111, 112 are pivotally connected to the distal end of the elongate shaft 101. In an alternative arrangement, one of the jaw members 111, 112 is provided in fixed relation to the elongate shaft 101 while the other jaw member 111, 112 is pivotally connected to the elongate shaft 101. The jaw members 111, 112 comprise a pair of opposing surfaces configured to grip and clamp tissue or vessels. In certain arrangements, the jaw members comprise one or more electrodes arranged on or as the inner opposed surfaces of the jaws. In such arrangements, the electrodes are electrically connected to the handle 120 to receive an electrosurgical RF signal for the sealing or coagulation of tissue. The jaw members 111, 112 are further provided with a slot or other opening within the inner opposed surfaces through which the blade may protrude when deployed.

[0058] In an alternative embodiment (not shown), the surgical device does not comprise an elongate shaft. Instead, the end effector 110 can be directly connected to the hand-piece 120. The handle portion 121 may be fixedly connected to the first jaw member 111 to form a first scissor portion, while the lever 122 may be fixedly connected to the second jaw member 112 to form a second scissor portion. By crossing the first scissor portion with the second scissor portion and providing a pivot point therebetween, the action of the surgical device may be configured similarly to that of a typical pair of scissors or pliers.

[0059] Irrespective of the way in which the end effector 101 is connected to the hand-piece 120, the surgical device 100 is configured such that moving the two portions of the hand-piece together (for example by closing the lever 122 towards the handle portion 121), moves the jaw members 111, 112 towards each other, so that the end effector 110 can grip or clamp tissue or vessels. The surgical device 100 is configured such that only when the jaw members 111, 112 are closed may the blade be deployed. In this respect, the surgical device 100 comprises a locking component 140.

[0060] FIG. 3A illustrates a first side of the locking component 140 according to an embodiment. The locking component 140 comprises a compliant body 141. The compliant body 141 is planar, that is to say, it lies in a plane. The compliant body 141 is stadium-shaped, that is to say, the compliant body is formed in the shape of a stadium, otherwise known as a discorectangle or an obround. The compliant body 141 may be defined by a rectangle with semicircles at a pair of opposite side. The compliant body 141 may have a plane shape consisting of two semicircles connected by parallel lines tangent to their endpoints.

[0061] In the arrangement shown, the compliant body 141 comprises a first straight portion 141a and a second straight portion 141b. The first and second straight portions 141a, 141b have the same length and are positioned parallel to one another. The compliant body 141 further comprises a first semi-circular portion 141c and a second semi-circular portion 141d. A first end of each of the semi-circular portions 141c, 141d is connected to the first straight portion 141a and a second end of each of the semi-circular portions 141c, 141d is connected to the second straight portion 141b. The perpendicular separation between the straight portions 141a, 141b is equal to the diameter of each semi-circular portion 141c, 141d. The compliant body 141 may have an axis of symmetry lying midway between the straight portions 141a, 141b and extending parallel thereto. The compliant body 141 may have an axis of symmetry bisecting the straight portions 141a, 141b.

[0062] As shown, the compliant body 141 is a closed loop. The material that defines the loop has a quadrilateral cross section. In some arrangements, the cross section may be a rectangle or a square. In the arrangement shown, one of the pairs of opposite surfaces of the rectangular cross section is parallel to the plane in which the compliant body 141 is defined. The shape of the compliant body 141 is configured to act as a biasing means. In this way, the compliant body 141 will deform when a force is applied thereto and, once the force is removed, it will return to its equilibrium or resting position as shown in FIG. 3A. The compliant body 141 is particularly flexible when deformed in a direction that lies in the plane of the compliant body 141 and that is substantially perpendicular to the straight portions 141a, 141b. The compliant body 141 is preferably not a coil spring.

[0063] FIG. 3B illustrates a second side of the locking component 140. The locking component 140 comprises a latch member 143. In the arrangement shown, the first latch member 143 is a cylinder extending from the plane of the compliant body 141 in a direction perpendicular to the plane of the compliant body 141. As will be described later, the first latch member 143 is configured to prevent the blade from being deployed when the jaw members are in the open position. This can be achieved by the first latch member 143 comprising a pin, configured to be received in a slot or notch comprised in the blade. In alternative arrangements, the locking mechanism may be configured in an opposite manner, such that the latch member of the locking component 140 may be a slot or notch configured to receive a pin fixed to the blade. Therefore, the locking component 140 comprises a latch member configured to mechanically interact with the blade. In this way, such a mechanical interaction may be achieved by any suitably cooperating components on the locking component and the blade such that the locking component is configured to be releasably connected to the blade.

[0064] The first latch member 143 is connected to and located within the compliant body 141. That is to say, the first latch member 143 is positioned on the locking component 140 within the boundary defined by the compliant body 141. With respect to the plane of the compliant body 140, at least a portion of the first latch member 143 is comprised within the closed loop of the compliant body 141. In the example shown, the latch member 143 is positioned between the straight portions 141a, 141b and between the semi-circular portions 141c, 141d of the compliant body 141.

[0065] The locking component 140 comprises a rib 142 fixed to the compliant body 141. The rib 142 is fixed at a single point along the compliant body 141. In the arrangement shown, the rib 142 extends from the first straight portion 141a of the compliant body 141 in the plane thereof, towards the second straight portion 141b. In this way, the rib 142 extends into the boundary of the compliant body 141, that is to say, into the interior of the closed loop. In the arrangement shown, the rib 142 is fixed to only one of the portions 141a, 141b, 141c, 141d of the compliant body 141.

[0066] The rib 142 is substantially planar. In the arrangement shown in FIG. 3B, the rib is substantially rectangular and comprises a first side 142a and a second side 142b, opposite and parallel to the first side 142a. The rib 142 is arranged such that the two straight sides 142a, 142b are perpendicular to the straight portions 141a, 141b of the compliant body 141. As will be described later, the sides 142a, 142b are configured to slide along a part of the handle portion 121 in order to constrain the movement of the rib 142. The first latch member 143 is connected to the compliant body 141 by the rib 142. A proximal end of the rib 142 is fixed to the compliant body 141 while the first latch member 143 is comprised at a distal end of the rib 142. In the arrangement shown, in which the latch member 143 is a pin, the pin extends from the rib 142 in a direction perpendicular to the plane thereof.

[0067] The locking component may further comprise an arm 144. The arm 144 is a protrusion extending from the compliant body 141. The arm 144 may extend from the same portion of the compliant body 141 as the rib 142. In the arrangement shown, the arm 144 extends from the first straight portion 141a of the compliant body 141. The arm 144 may extend from substantially the same point along the compliant body 141 as the rib 142. The arm 144 extends outwardly from the compliant body 141 in a direction substantially parallel to the plane thereof. Therefore, the arm 144 may extend from the compliant body 141 in an opposite direction to the rib 142. In the arrangement shown, the arm 144 is fixed to the first straight portion 141a and extends in a direction away from the second straight portion 141b of the compliant body 141. In this way, the arm 144 lies outside of the boundary of the compliant body 141, that is to say, outside of the loop.

[0068] Any or all parts of the locking component may comprise a polymer and may be formed by injection moulding or additive manufacturing, such as 3D printing. The locking component may consist solely of a polymer material. The locking component 140 may consist solely of the compliant body and the latch member. The locking component 140 may consist solely of the compliant body 141, the rib 142 and the latch member 143. The locking component 140 may consist solely of the compliant body 141, the rib 142, the latch member 143 and the arm 144. The locking component 140 may comprise a single integral component. That is to say, the parts of the locking component 140 may be formed integrally with the locking component 140 without the need to fix or connect separate pieces together. Preferably, the locking component is formed of a single moulding and is more preferably formed of a single polymer moulding, which may be manufactured using injection moulding.

[0069] FIG. 4 illustrates part of the surgical device 100 as viewed from a first side. In particular, FIG. 4 shows the internal details of the handle portion 121 of the hand-piece 120 and demonstrates how the locking component 140, described above, can be comprised in the surgical device 100. The handle portion 121 comprises first and second sidewalls that can be fixed together by any suitable fastening means. In the arrangement shown, the sidewalls are fixed together by a clamshell assembly in which the sidewalls can be press-fitted together by the communication between one or more pins and one or more holes. The handle portion 121 further comprises a support 124. The support is comprised within the handle portion 121 between the sidewalls. The support 124 is substantially planar and lies in a plane substantially parallel to the plane of at least one of the sidewalls. The support 124 may comprise one or more holes to accommodate the fastening means connecting the sidewalls together. In this way, the support 124 is fixed relative to the handle portion 121. The support 124 further comprises a blade track 125a. The blade track 125a is an aperture through the support 124 that extends parallel to the longitudinal axis of the surgical device 100 and/or the blade 130.

[0070] At least a portion of the blade 130 is comprised in the handle portion 121. In FIG. 4, the blade 130 is positioned behind the support 124. FIG. 4 also shows a trigger arm 132 which forms part of the trigger mechanism operable to deploy the blade 130. The blade 130 is pivotally connected to the trigger arm 132 by a pivot pin 133. The pivot pin 133 can be received by the blade track 125a and is configured to slide along the blade track 125a when the blade 130 moves axially with respect to the support 124.

[0071] The first side of the locking component 140 can also be seen in FIG. 4. The locking component 140 is shown here in its first position. The locking component 140 is held in the handle portion 121, preferably sandwiched between the first sidewall and the support 124. In the arrangement shown, the plane of the compliant body 141 is parallel to the plane of the support 124. The second side of the locking component 140, that is the side on which the first latch member 143 is comprised, may face the support 124 while the first side of the locking component 140 may face the first sidewall of the handle portion 121.

[0072] The first sidewall of the handle portion 121 comprises one or more rails. In the arrangement shown, the handle portion 121 comprises a first rail 151 and a second rail 152. The rails 151, 152 are straight ridges on an internal surface of the handle portion 121 and are parallel to one another. The rails 151, 152 may extend in a direction perpendicular to the longitudinal axis of the surgical device and/or to the longitudinal axis of the blade 130. The rails 151, 152 are spaced so as to receive the rib 142. In the arrangement shown, the first side 142a of the rib 142 is configured to slide along the first rail 151 while the second side 142b of the rib 142 is configured to slide along the second rail 152. In this way, the rails 151, 152 are configured as a guide for the rib 142 to constrain the movement of the rib 142 in a direction perpendicular to the blade 130.

[0073] Although it is not visible in FIG. 4, the first latch member 143 projects from the rib 142 towards the second sidewall. To accommodate this, a notch 125b is provided in the support 124. The notch 125b is configured to allow the first latch member 143 to slide therealong in a direction perpendicular to the longitudinal axis and parallel to the rails 151, 152. In the arrangement shown, the notch 125b is an aperture through the thickness of the support 124 and is a transverse extension of the blade track 125a. Therefore, the blade track 125a and the notch 125b form a T-shaped aperture in the support 124 to allow the pivot pin 133 to slide axially and to allow the first latch member 143 to slide transversely, with respect to the support 124.

[0074] FIG. 5 illustrates part of the surgical device 100 as viewed from a second side, that is, the opposite side to the view in FIG. 4. The first position of the locking component 140 and parts thereof is shown in phantom lines and labelled using the same reference numerals as in FIGS. 2 to 4, while the second position of the locking component 140′ and parts thereof is labelled using the corresponding reference numerals with a prime (′) symbol.

[0075] Additional details of the blade 130 are illustrated in FIG. 5. The blade comprises a first edge 130a and a second edge 130b. The blade 130 is positioned in the handle portion 121 such that the edges 130a, 130b lie in the same plane that is parallel to the plane of the support 124. Furthermore, the blade 130 is arranged such that the second edge 130b is disposed between the first edge 130a and the lever 122.

[0076] The blade 130 comprises a second latch member 131 configured to mechanically interact with the first latch member 143 on the locking component 140. In the arrangement shown, the second latch member 131 is a cut-out portion through the thickness of the blade 130. The second latch member 131 is comprised in the first edge 130a of the blade 130. In this way, the second latch member 131 faces away from the lever 122. The second latch member 131 is sized and shaped so as to cooperate with the first latch member 143. In the illustrated arrangement, the first latch member is a pin 143 and the second latch member is a slot 131 configured to receive the pin 143. The second latch member 131 is configured to allow the first latch member 143 to move in and out thereof. It will be appreciated that other cooperating components able to facilitate a mechanical interaction between the locking component 140 and the blade 130 could be employed instead of, or in addition to, a pin in a corresponding slot.

[0077] In a first position, the first latch member 143 is engaged with the second latch member 131 such that the blade 130 is prevented from moving along its axis. Therefore, the latch member 143 of the locking component 140 prevents deployment of the blade 130 when in a first position. In a second position, the first latch member 143′ is disengaged from the second latch member 131 such that the blade 130 can move along its axis. Therefore, the latch member 143′ of the locking component 140′ does not hinder the motion of the blade 130, and therefore allows the trigger mechanism to deploy the blade 130.

[0078] As shown in FIGS. 4 and 5, the support 124 is positioned between the blade 130 and the locking component 140. The first latch member 143 extends through the notch 125b of the support 124 in order to engage the second latch member 131. The arm 144 of the locking component 140 extends out of the handle portion 122 via an aperture 127 provided therein in order to contact the lever 122. In this way, the locking component 140 is configured to move in response to manipulation of the lever 122. The locking component 140 is positioned in the handle portion 121 such that the first straight portion 141a of the compliant body 141, i.e. the portion to which the latch member is connected, is closer to the lever 122 than the second straight portion 141b. In other words, the first straight portion 141a is positioned between the lever 122 and the second straight portion 141b.

[0079] As mentioned above, the sidewalls of the handle portion 121 are fixed together by any suitable fastening means. In the arrangement shown, at least one of the fastening means is configured to limit the movement of the locking component 140. In particular, a first limiter 126a and a second limiter 126b extend from the first sidewall to the second sidewall of the handle portion 121, through holes in the support 124. The first limiter 126a is positioned in proximity to the second straight portion 141b and outside of the boundary of the compliant body 141. In particular, the first limiter 126a is positioned along the axis of motion of the rib 142 and the latch member 143. Otherwise stated, the first limiter 126a is located along a transverse axis defined by the rib 142, latch member 143 and notch 125b. The first limiter 126a may be substantially rounded so as to provide a smooth surface against which the compliant body 141 can bear. The second limiter 126b may be positioned in proximity to the first straight portion 141a and inside the boundary of the compliant body 141. The second limiter 126b may be located at a position offset from the transverse axis along which the rib 142 is able to slide. Preferably, the locking component 140 is not fixedly connected to any other component in the surgical device. Instead, the locking component 140 is free to move within the handle portion 121 subject to one or more mechanical constraints. As noted above, the rib 142 is constrained to slide along the rails 151, 152; the first latch member 143 is constrained to move along the notch 125b; and the compliant body 141 is constrained by one or more limiters (such as the first limiter 126a) in the handle portion 121.

[0080] The surgical device 100 is configured such that the handle 121 and lever 122 are held in an open position as shown in FIGS. 1 and 4. By virtue of the shape of the locking component 140 and its arrangement within the surgical device 100, the compliant body 141 acts as a biasing means to exert a reaction force against the first limiter 126a and thereby retain the first straight portion 141a towards the lever 122 and away from the second straight portion 141b. In this way, the compliant body 141 biases the rib 142 towards the lever 122 (i.e. downwards in FIGS. 4 and 5) such that the first latch member 143 engages the blade 130 via the second latch member 131, thereby preventing the blade 130 from being moved axially by the trigger arm 132.

[0081] In operation, a practitioner may position the first and second jaw members 111, 112 around tissue or one or more vessels and close the jaw members 111, 112 by forcing the handle 121 and the lever 122 towards each other. In doing so, the lever 122 forces the first latch member from its first position (143) to its second position (143′). In the arrangement shown, the lever 122 being forced towards the handle portion 121 moves the arm of the locking component from a first position (144) to a second position (144′). Given that the arm 144 is connected to the same portion of the compliant body 141 as the rib 142, this movement will force the rib 142 along the rails 151, 152 towards the first limiter 126a (i.e. upwards in FIGS. 4 and 5). Accordingly, the first latch member 143 is also moved towards the limiter 126a and is released from the second latch member 131. While holding the lever 122 closed such that the first latch member is in its second position, the practitioner may operate the trigger mechanism to deploy the blade 130 such that it moves along its longitudinal axis towards the end effector 110 (i.e. to the left in FIG. 5) and protrudes out of a slot (not shown) provided between the first and second jaw members 111, 112, to thereby cut the required tissue. As mentioned above, the movement of the blade 130 may be constrained by the pivot pin 133 sliding along the blade track 125a.

[0082] Following this, the blade 130 may be automatically returned (i.e. to the right in FIG. 5) by the trigger mechanism to the position shown in FIG. 5, i.e. its resting position, such that the second latch member 131 is re-aligned with the first latch member 143 along the transverse axis. By reducing the force on the lever 122 to thereby allow it to be returned to its first position away from the handle portion 121, the compliant body 141 biases the first latch member from its second position (143′) to its first position (143) in which it is engaged with the second latch member 131 by a mechanical interaction therewith.

[0083] Should a practitioner activate the trigger mechanism when the jaws 111, 112 are in the open position (i.e. when the lever 122 and the handle 121 are held away from one another), the mechanical interaction between the locking component 140 and the blade 130 will prevent the blade 130 from moving into its deployed position. Instead, the engagement between the first latch member 143 and the second latch member 131 may transfer the triggering force to the locking component 140. In view of the positioning of the first latch member 143 in the notch 125b, at least a portion of the triggering force may be transferred to the support 124 via the first latch member 143. Moreover, in view of the positioning of the rib 142 between the rails 151, 152, and in particular the second side 142b bearing against the second rail 152 (see FIG. 4), at least a portion of the triggering force may be transferred to the first sidewall via the rib 142.

[0084] Various modifications, whether by way of addition, deletion and/or substitution, may be made to all of the above described embodiments to provide further embodiments, any and/or all of which are intended to be encompassed by the appended claims.