GB2582319A

GB2582319A - Electrosurgical instrument

Info

Publication number: GB2582319A
Application number: GB1903713.4A
Authority: GB
Inventors: Dickson James
Original assignee: Gyrus Medical Ltd
Current assignee: Gyrus Medical Ltd
Priority date: 2019-03-19
Filing date: 2019-03-19
Publication date: 2020-09-23
Anticipated expiration: 2039-03-19
Also published as: GB201903713D0; GB2582319B

Abstract

A pivot assembly 200 for a surgical forceps instrument with deployable blade 302, the blade prevented from deploying while forceps jaws 202, 204 are open by mechanical interaction with pivot pin 206. The mechanical interaction may be one or more protrusions 402 of the pivot pin with complementary notches 404 in the blade or vice versa. The protrusion may be an orthogonally projecting fin or boss. The pivot pin may be rotationally locked to one jaw member with the other jaw member able to pivot around it. The pivot assembly may be in an end effector for a surgical instrument that may be part of an electrosurgical instrument or system. Surgical forceps with two jaw members where one or more pivots around a pivot pin, a cutting blade deployable when the jaws are closed and a lock to lock the blade to the pivot pin when the jaws are open.

Description

ELECTROSURCICAL INSTRUMENT

Technical Field

Embodiments of the present invention described herein relate to an electrosurgical device, and in particular an clectrosurgical forceps device wherein a mechanical blade S provides a tissue cutting action in combination with electrosurgical electrodes providing a tissue coagulation or sealing effect.

Background to the Invention and Prior Art

Electrosurgical instruments provide advantages over traditional surgical instruments in that they can be used for coagulation and tissue sealing purposes.

Electrosurgical forceps are used to clamp tissue or vessels before cutting and/or sealing the tissue. The problem to be solved is unintended mechanical blade deployment, prior to clamping and sealing tissue with a vessel sealing device. It is preferable to include a feature within a vessel sealing device which reduces or eliminates user en-ors through design.

One such prior art arrangement is known from US 2011/054472 A, which describes an open electrosurgical forceps including a pair of first and second shaft members each having a jaw member disposed at its distal end. The jaw members are movable about a pivot assembly from an open position in spaced relation relative to one another to a closed position wherein the jaw members cooperate to grasp tissue. One or both of the jaw members includes a knife channel defined along its length. The pivot assembly includes a knife slot and is configured to prevent reciprocation of a cutting mechanism when the jaw members are disposed in the open position and to permit. reciprocation of the cutting mechanism when the jaw members are disposed in the closed position.

Summary of the Invention

Embodiments of the present invention provide an improved surgical instrument having an end effector mounted on the end of an elongate shaft extending from a handle. The end effector is capable of several different operations, including grasping, cutting, and scaling and/or coagulating tissue. The surgical instrument includes a blade assembly having a cutting blade at its distal end. The trigger mechanism is arranged to drive the blade assembly longitudinally within the elongate shaft such that the cutting blade protrudes between the jaw members. In order to prevent unintended mechanical blade deployment, prior to clamping and sealing tissue, there is a mechanical interaction between the jaw pivot pin and the blade slot, or another feature within the blade. This can be achieved via locking the rotation of the pivot pin to one of the jaw members, such that the pivot pin rotates with one jaw member.

In view of the above, in a first aspect the present invention provides a pivot assembly for a surgical forceps instrument configured to prevent deployment of a cutting blade when a first jaw member and a second jaw member are disposed in an open position and to permit deployment of the cutting blade when the first and second jaw members are disposed in a closed position. wherein the pivot assembly prevents deployment of the cutting blade by a mechanical interaction between a pivot pin and the cutting blade when the first and second jaw members are disposed in the open position.

Such an arrangement is advantageous as it prevents deployment of the cutting blade whilst the jaw members are in the open position. This reduces the incidence of a user cutting tissue, prior to clamping the tissue. Another advantage of this configuration is that the cutting blade cannot he deployed around a curved blade track while the jaws are still open. This reduces the likelihood that the cutting blade can 'derail' from the blade track while the jaws are in their open position.

In one embodiment the arrangement is such that the mechanical interaction between the pivot pin and the cutting blade when the first and second jaw members are disposed in the open position is via a protruding feature which slots into a complementary notch. locking the cutting blade in place and preventing deployment of the cutting blade.

In one embodiment the arrangement is such that the mechanical interaction between the pivot pin and the cutting blade when the first and second jaw members are disposed in the open position is via a first protruding feature and a second protruding feature which lock the cutting blade in place and prevent deployment of the cutting blade. In one embodiment the arrangement is such that the first protruding feature is on the pivot pin and the second protruding feature is on the cutting blade.

In one embodiment the arrangement is such that the protruding feature is on the pivot pin and the complementary notch is in the cutting blade.

In one embodiment the arrangement is such that the complementary notch is in the pivot pin and the protruding feature is on the cutting blade.

In one embodiment the arrangement is such that the protruding feature is a fin projecting orthogonally to the axis of the pivot pin.

In one embodiment the arrangement is such that the pivot pin is rotationally locked to the first or second jaw member.

In one embodiment the arrangement is such that the pivot pin is rotationally locked to the first or second jaw member by a splined shaft, laser welding, or adhesive. In one embodiment the jaw members are single action jaw members where one 10 of the first and second jaw members is movable about the pivot assembly and the other of the first and second jaw members is fixed with respect to the pivot assembly. In another embodiment both of the first and second jaw members may be movable about the pivot assembly.

Another aspect of the present disclosure provides an end effector for a surgical instrument comprising: a pair of first and second jaw members, at least one or both of the first and second jaw members movable about a pivot assembly as described above from an open position to a closed position; a cutting blade assembly located for longitudinal movement into a deployed position, the cutting blade assembly including a cutting blade at its distal end; and a trigger mechanism causing the longitudinal movement of the cutting blade assembly into its deployed position.

Another aspect of the present disclosure provides a surgical instrument, comprising: a hand-piece; a shaft, distal to the hand-piece; an end effector, at the distal end of the shaft, as described above.

Another aspect of the present disclosure provides a surgical instrument as described above, wherein: the surgical instrument is an electrosurgical instrument; each of the first and second jaw members includes an electrically conductive sealing surface for communicating electrosurgical energy through tissue held therebetween; and the shaft comprises RF electrical connections, drive componentry for the end effector portion, the end effector arrangement being operably connected to the drive componentry to drive the end effector to operate in use, and the electrically conductive sealing surface being connected to the RF electrical connections.

Another aspect of the present disclosure provides an electrosurgical system, comprising: an RF clectrosurgical generator; and an electrosurgical instrument as described above.

Another aspect of the present disclosure provides a surgical forceps instrument comprising: a first jaw member and a second jaw member, at least one or both of the first and second jaw members being arranged to pivot about a pivot pin between an open position and a closed position; a cutting blade permitted to deploy when the first and second jaw members are disposed in the closed position; and a locking means arranged to lock the cutting blade to the pivot pin when the first and second jaw members are in the open position.

In one embodiment the arrangement is such that the locking means comprises a first feature on the pivot pin and a second feature on the cutting blade, wherein the first and second features are interlocking complementary shapes which engage with one another when the first and second jaw members arc in the open position, and disengage from one another when the first and second jaw members arc in the closed position.

Brief Description of the Drawings

Embodiments of the invention will now be further described by way of example only and with reference to the accompanying drawings, wherein like reference numerals refer to like parts, and wherein: Figure 1 is a side view of an electrosurgical instrument according to an embodiment of the present invention.

Figure 2 is a side view of an end effector of an electrosurgical instrument, wherein the jaw members are closed.

Figure 3 is a side view of an end effector of an electrosurgical instrument, wherein the jaw members are open.

Figure 4 is a sectional view of an end effector of an electrosurgical instrument, wherein the jaw members are closed.

Figure 5 is a sectional view of an end effector of an clectrosurgical instrument, 30 wherein the jaw members arc open.

Figure 6 is a perspective view of an example pivot pin in isolation.

Figure 7 is a perspective view of an example pivot pin in isolation.

S

Figure 8 is a representation of an electrosurgical system including a generator and an instrument in accordance with embodiments of the invention.

Description of the Embodiments

Referring to the drawings, Figure 1 shows an electrosurgical instrument 100 S according to an example of the present invention. The instrument 100 includes a proximal handle portion 106, a shaft 104 extending in a distal direction away from the proximal handle portion, and a distal end effector assembly 102 mounted on a distal end of the shaft. The end effector assembly 102 may by way of example be a set of opposed jaws arranged to open and close, and comprising one or more electrodes arranged on or as the inner opposed surfaces of the jaws and which in use have connections to receive an electrosurgical radio frequency (RF) signal for the sealing or coagulation of tissue. The jaws are further provided with a slot or other opening within the inner opposed surfaces through which a mechanical cutting blade or the like may protrude, when activated by the user. In use, the handle 106 is activated by the user in a first manner to clamp tissue between the jaws 102, and in a second manner to supply the RF current to the electrodes in order to coagulate the tissue. The jaws 102 may be curved so that the active elements of the instrument 100 are always in view. This is important in vessel sealing devices that are used to operate on regions of the body that obscure the user's vision of the device during use. The handle 106 may he activated by the user in a third manner to cause the blade to protrude between the jaws 102, thereby cutting the tissue clamped between. Once the required cutting and sealing has been completed, the user can release the tissue from the jaws 102. The handle portion 106 includes a clamping handle 114 for clamping tissue between the end effector jaws 102, a trigger 112 for cutting the tissue, switch 108 for activating and deactivating the RF supply to the electrodes in the jaws 102 in order to coagulate tissue, and a rotation wheel 110 for rotating the jaws 102 in order to reach tissue from different angles.

Figures 2 and 3 show the distal end effector assembly 102 in more detail. The end effector comprises an upper jaw 202 pivotably connected to a lower jaw 204 about a pivot 206. One or both of the jaw members 202 and 204 can be moveable, provided that the pivot pin's 206 rotation is locked to a single moving jaw member 202 or 204. Flanges 210 are present at the proximal end of upper jaw 202, while flanges 212 are present at the proximal end of lower jaw 204. The flanges 210 and 212 each have slots 214 through which a drive pin 208 extends, such that proximal and distal movement of the drive pin 208 (by means of a drive mechanism (not shown) causes the jaws 202 and 204 to pivot between open and closed positions as shown in Figure 2 and Figure 3 respectively. A pivot assembly 200 comprises: the pivot 206; flanges 210 and 212, each having slots 214; and the drive pin 208. In Figure 3, the end of the cutting blade 302 can be seen between the two jaws 202 and 204. In this open position, the cutting blade 302 cannot deploy as it is locked in place by the pivot assembly 200, as will be described later. Conceivably, the cutting blade could be any suitable cutting mechanism.

A metallic shim 216 is present on the inward lace of upper jaw 202, while a 10 metallic shim 218 is present on the inward face of lower jaw 204. When the jaws 202 and 204 pivot into their closed position, the metallic shims 216 and 218 come into close proximity one with the other, in order to grasp tissue (not shown) therebetween.

Figures 4 and 5 show sectional views of the pivot assembly 200 lock mechanism for the cutting blade 302 when the jaws are in a closed and an open position respectively.

The pivot pin 206 is aligned with the centre of the blade slot 406. The rotation of the pivot pin 206 is locked to the one of the jaw members 202 or 204, such that the pivot pin 206 is rotated with the jaw member 202 or 204. Locking the rotation of the pivot pin 206 to one of the jaw members 202 or 204 could be achieved through a splincd shaft, laser welding, adhesive, or any other appropriate means. The pivot pin 206 has a protruding feature 402 extending outwards from its shaft 602 (see Figure 6) which is arranged to prevent the cutting blade 302 from deploying until a defined jaw closure angle is reached. The exact angle at which the blade 302 is free to deploy is tuneable by altering geometry and clearances. Design iteration is required to optimise the exact pin 206 and blade slot 302 geometry. The protruding feature 402 of the pivot pin 206 locks to the cutting blade 302 when the jaws 202 and 204 are open, and unlocks from the cutting blade 302 when the jaws 202 and 204 are closed. The protruding feature 402 of the pivot pin 206 locks to the cutting blade 302 by slotting into a complementary notch 404 in the cutting blade 302 when the jaws 202 and 204 are open. When the jaws 202 and 204 are closed, the protruding feature 402 rotates such that the feature 402 slots out of the complementary notch 404, allowing the cutting blade 302 to deploy.

Although the description herein describes the pivot pin 206 having the protruding feature 402 with the cutting blade 302 containing the complementary notch 404, it is obvious that the cutting blade 302 could have the protruding feature 402 with the pivot pin 206 containing the complementary notch 404. Further, both the cutting blade 302 and the pivot pin 206 could have a protruding feature each, with a locking mechanism between the two protruding features.

The cutting blade 302 is deployed via a trigger mechanism when the jaws 202 and 204 arc closed. The drive handle (114) closes the jaws 202 and 204, and the trigger mechanism to deploy the cutting blade is operated via a trigger 112. The trigger mechanism is arranged to drive the blade assembly longitudinally within the elongate shall such that the cutting blade 302 protrudes between the closed jaw members 202 and 204.

Figures 6 and 7 show perspective views of an example pivot pin 206. The pivot pin 206 comprises a head 604, a shaft 602, and a protruding feature 402. In this example, the protruding feature 402 is a fin with a rectangular shape, one rounded corner, and one corner with a cut out portion and a tooth 606. The tooth 606 is shaped to fit within the notch 404. The diagonally opposite corner to the tooth also slots into a cut-out in the cutting blade. Conceivably, the protruding feature 402 could be any shape which allows locking to the cutting blade 302 via a suitably shaped notch 404.

Referring now to Figure 8, the instrument 100 in use is intended for connection to an electrosurgical generator 800 having a controllable radiofrequency (RF) source therein (not shown) that in use produces an RF coagulation signal that coagulates or seals tissue when applied thereto via the electrodes of the end effector of the instrument 100. Electrosurgical generator 800 includes control input switches 804 and 802, to respectively allow the generator to be turned on and off, and to allow the power of the RF coagulation signal fed to the instrument 100 to be controlled. In these respects, the electrosurgical generator 800 is conventional.

The instrument 100 is connected in use to generator 800 by control and power line 806, which contains separate electrical lines to allow an RF signal to be fed to the end effector of the instrument 100 via internal wiring, and also to allow a control signal to he received from the switch 108 of the instrument 100, to command the electrosurgical generator to output an RF coagulation signal to the instrument 100. In use the surgeon activates the generator via on-off switch 804, and selects the coagulation or sealing signal strength to be generated by the internal RF source using buttons 802. During a surgical procedure with the instrument when a sealing or coagulation RF signal is required at the end effector, the surgeon controls the generator to produce such a signal by pressing the switch 108 on the instrument, the generated RF signal then being passed via the electrical lines 806 to the end effector. That is, pressing of the switch 108 in use causes an RF coagulation or sealing signal to be supplied to the appropriate electrodes contained within the end effector.

Various modifications can be made to the above to provide further embodiments. For example, in one modification the pivot pin 206 may be a straight pin with no head, which is laser welded on one or both ends. In addition, in another modification the jaws are arranged as single action jaws where one jaw is fixed, and only the other jaw moves.

The pivot pin lock could still work in this configuration as there is still one moving jaw that could be fixed to the rotation of the pin. Moreover, in a third modification the protruding feature need not be a fin or fin shaped, but can instead be a boss or other wider' feature than a fin. For example, the protruding feature may in some examples he much wider than the blade if there is space in the assembly to allow this. Any of these modifications may be used together in any combination, or individually to provide further embodiments of the invention.

Various modifications whether by way of addition, deletion, or substitution of features may be made to above described embodiment to provide further embodiments, 20 any and all of which are intended to be encompassed by the appended claims.

Claims

Claims 1. A pivot assembly for a surgical forceps instrument configured to prevent deployment of a cutting blade when a first jaw member and a second jaw member are disposed in an open position and to permit deployment of the cutting blade when the first and second jaw members are disposed in a closed position, wherein the pivot assembly prevents deployment of the cutting blade by a mechanical interaction between a pivot pin and the cutting blade when the first and second jaw members are disposed in the open position.
2. The pivot assembly of claim I, wherein the mechanical interaction between the pivot pin and the cutting Made when the first and second jaw members are disposed in the open position is via a protruding feature which slots into a complementary notch, locking the cutting blade in place and preventing deployment of the cutting blade.
3. The pivot assembly of claim 1, wherein the mechanical interaction between the pivot pin and the cutting blade when the first and second jaw members are disposed in the open position is via a first protruding feature and a second protruding feature which lock the cutting blade in place and prevent deployment of the cutting blade.
4. The pivot assembly of claim 3, wherein the first protruding feature is on the pivot pin and the second protruding feature is on the cutting blade.
5. The pivot assembly of claim 2, wherein the protruding feature is on the pivot pin and the complementary notch is in the cutting blade.
6. The pivot assembly of claim 2, wherein the complementary notch is in the pivot pin and the protruding feature is on the cutting blade.
7. The pivot assembly of claim 2, 5 or 6, wherein the protruding feature is a fin projecting orthogonally to the axis of the pivot pin.
8. The pivot assembly of any of claims 2, 5, or 6, wherein the protruding feature is a boss projecting orthogonally to the axis of the pivot pin.
9. The pivot assembly of any of the preceding claims, wherein the pivot pin is rotationally locked to the first or second jaw member.
10. The pivot assembly of claim 9, wherein the pivot pin is rotationally locked to the first or second jaw member by a splined shaft, laser welding, or adhesive.
11. The pivot assembly of any of the preceding claims, where the jaw members are single action jaw members where one of the first and second jaw members is movable about the pivot assembly and the other of the first and second jaw members is fixed with respect to the pivot assembly.
12. An end effector for a surgical instrument comprising: a pair of first and second jaw members, at least one or both of the fu-st and second jaw members being movable about a pivot assembly according to any of the preceding claims from an open position to a closed position; a cutting blade assembly located for longitudinal movement into a deployed position, the cutting blade assembly including a cutting blade at its distal end; and a trigger mechanism causing the longitudinal movement of the cutting blade assembly into its deployed position.
13. A surgical instrument, comprising: a hand-piece; a shaft, distal to the hand-piece; an end effector, at the distal end of the shaft, according to claim 12.
14. The surgical instrument of claim 13, wherein: the surgical instrument is an electrosurgical instrument; each of the firs( and second jaw members includes an electrically conductive sealing surface for communicating electrosurgical energy through tissue held therebetween; and the shaft comprises RF electrical connections, chive componentry for the end effector portion, the end effector arrangement being operably connected to the drive componentry to drive the end effector to operate in use, and the electrically conductive scaling surface being connected to the RF electrical connections.
15. An electrosurgical system, comprising: an RF electrosurgical generator: and an electrosurgical instrument according to claim 14.
16. A surgical forceps instrument comprising: a first jaw member and a second jaw member, at least one or both of the first and second jaw members being arranged to pivot about a pivot pin between an open position and a dosed position; a cutting blade permitted to deploy when the first and second jaw members are disposed in the closed position; and a locking means arranged to lock the cutting blade to the pivot pin when the first and second jaw members are in the open position.
17. The surgical forceps instrument of claim 16, wherein the locking means comprises a first feature on the pivot pin and a second feature on the cutting blade, wherein the firs( and second features are interlocking complementary shapes which engage with one another when the first and second jaw members are in the open position, and disengage from one another when the first and second jaw members are in the closed position.