GB2565133A

GB2565133A - Bipolar surgical instruments

Info

Publication number: GB2565133A
Application number: GB1712540.2A
Authority: GB
Inventors: Alan Dickson James
Original assignee: Gyrus Medical Ltd
Current assignee: Gyrus Medical Ltd
Priority date: 2017-08-04
Filing date: 2017-08-04
Publication date: 2019-02-06
Anticipated expiration: 2037-08-04
Also published as: GB2565133B; GB201712540D0

Abstract

A bipolar surgical instrument 1comprises a body 2 and first and second opposed jaws located at the distal end of a shaft, movable between an open position in which the first and second jaws are spaced apart from one another, and a closed position. An actuation grip 8 is movably mounted on the body 2, is arranged to operate an actuation shaft, and is biased towards the open position by an actuation grip return force. An actuation assistor 60 is located in a fixed grip of the instrument 1 and is arranged to hold the actuation grip 8 in the closed position with a predetermined force greater than zero and less than the actuation grip return force. The actuation assistor 60 may be resiliently biased, such that when no pressure is applied to the moveable grip 8 the return grip force will open the jaws of the instrument. The actuation grip 8 has a protrusion 58 which may be resiliently biased.

Description

BIPOLAR SURGICAL INSTRUMENTS

The present invention relates to bipolar surgical instruments.

BACKGROUND OF THE INVENTION

Bipolar surgical instruments are used to clamp and seal tissue, particularly blood vessels, during surgical procedures. Clamping is typically achieved using a pair of opposed jaws that are remotely operable to clamp around the tissue being sealed. Sealing is typically achieved using application of radio frequency energy delivered to the tissue being sealed by electrodes mounted on the opposed jaws of the instrument.

In order to effectively seal a vessel using bipolar energy, it is advantageous for the force exerted by the jaws on the tissue to be substantially constant over the duration of the seal. This reduces the number of variables which the sealing waveform must overcome in order to provide a reliable seal. Existing devices, particularly which are used to seal large vessels, generally maintain this constant jaw force using a latch mechanism which is engaged once the jaw actuating handle is compressed to its maximum extent. The handle can then be released by the user while the jaw force remains in place. To release the latch, the handle is normally squeezed again, and the jaw force is removed. The disadvantage of this workflow is that the handle must be squeezed once io close jaws, and once again fo release jaws. Some surgeons prefer to work without a latch, and some believe it is a faster way to work in certain situations. The problem with not having a latch mechanism is the variability in jaw clamping force over the duration of the seal, as this force is now reliant on the surgeon to maintain.

Therefore, it is desirable to provide a bipolar surgical instrument that is able to apply a constant jaw closure force during vessel sealing, without latching the handle in place.

SUMMARY OF THE INVENTION

Aspects of the present invention are set out in the attached claims.

According to one exemplary aspect, there is provided a bipolar surgical instrument comprising a body; a fixed grip which extends from the body; an elongate shaft attached to, and extending from, the body, the shaft extending to a distal end; first and second opposed jaws located at the distal end of the shaft, the first jaw being movable with respect to the second jaw between an open position in which the first and second jaws are spaced apart from one another, and a closed position in which the first and second jaws are adjacent one another; an actuation shaft connected with at least the first jaw, the actuation shaft being movable with respect to the body and the shaft between a first position in which the jaws are in the open position, and a second position in which the jaws are in the closed position; an actuation grip movably mounted on the body, and arranged to operate the actuation shaft, the actuation grip having a released position in which the actuation shaft is in the first position, and an engaged position in which the actuation shaft is in the second position; a bias element arranged to bias the actuation grip towards the released position with an actuation grip return force; and an actuation assistor located in the fixed grip and arranged to hold the actuation grip in the second position with a predetermined force greater than zero and less than the actuation grip return force.

In one example, the actuation grip is mounted on a pivot point for rotation with respect to the body and fixed grip.

In one example, the actuation assistor includes a cam surface, and the actuation grip includes an engagement portion which movably engages the cam surface within the fixed grip, the cam surface defining a receiving aperture for receiving the engagement portion therein when the actuation grip is in the second position, the receiving aperture being shaped so as to hold the engagement portion with the predetermined force.

In one example, the actuation assistor is slidable with respect to the fixed grip and is resiliently biased towards the pivot point, and wherein the engagement portion is fixed relative to the actuation grip.

In one example, the actuation assistor is biased by a resilient member fixed at one end to the fixed grip.

In one example, the actuation assistor is provided by a resilient member which extends into the fixed grip.

In one example, the actuation assistor is fixed with respect to the body, and wherein the engagement portion is movable and resiliently biased relative to the actuation grip.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1 and 2 show side views of a bipolar surgical instrument embodying one aspect of the present invention in open and closed positions respectively;

Figures 3 and 4 show perspective views of part of the bipolar surgical instrument of Figures and 2 in open and closed positions respectively;

Figures 5 and 6 show side views of the part of the bipolar surgical instrument of Figures 3 and 4 in open and closed positions respectively;

Figure 7 shows a plan view of the part of the bipolar surgical instrument of Figures 3 to 6;

Figure 8 shows a perspective cross-sectional view of the bipolar surgical instrument of Figures 1 and 2;

Figure 9 shows a side cross-sectional view of the bipolar surgical instrument of Figures 1 and 2;

Figure 10 is a side cross-sectional view of first example actuation assistor arrangement for the instrument of Figures 1 and 2;

Figures 11A to 11C illustrate positions of the instrument of Figure 10;

Figure 12 is a side cross-sectional view of a second example actuation assistor arrangement for the instrument of Figures 1 and 2;

Figures 13A and 13B illustrate positions of the instrument of Figure 12;

Figure 14 is a side cross-sectional view of first example actuation assistor arrangement for the instrument of Figures 1 and 2; and

Figures 15A to 15C illustrate positions of the instrument of Figure 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An example bipolar surgical instrument 1 is shown schematically in Figures 1 and 2. Figure 1 illustrates an open position of the instrument 1, and Figure 2 illustrates a closed position thereof.

The instrument 1 comprises a body 2 having a main housing 4 from which a fixed grip 6 extends. The fixed grip 6 is held during use by the operator of the instrument 1. A movable actuation grip 8 is movably mounted on the main housing 4 of the body 2. An elongate shaft 10 is attached to the main housing 4 of the body 2, and extends from a proximal end 12 at the main housing 4, to a distal end 14 of the shaft 10. The shaft 10 defines a longitudinal axis therealong, and an elongate passage extends from the proximal end 12 to the distal end 14 of the shaft 10. As will be described in more detail below, an actuation shaft extends from the main housing 4 through the passage of the shaft 10.

A pair 16 of opposed jaws are located at the distal end 14 of the shaft 10. The pair 16 of jaws comprises a first jaw 18 and a second jaw 20. In the example of Figures 1 and 2, the first and second jaws 18 and 20 are pivotally mounted on a jaw pivot 22. The first and second jaws 18 and 20 are pivotable about the jaw pivot 22, between an open position (as shown in Figure 1) in which the jaws 18 and 20 are separated from one another, and a closed position (as shown in Figure 2) in which the jaws 18 and 20 are adjacent one another. In another example of a bipolar instrument embodying the present invention, only one of the jaws is movable. In another example, the movable jaw or jaws may be movable in any suitable manner, for example linearly, or in a combination of rotation and linear movement. The exact nature of the movement of the jaws is not important in the context of the present invention.

As will be described in more detail below, the operator of the instrument 1 moves the actuation grip 8 from a first position (shown in Figure 1) to a second position (shown in Figure 2) in order to move the jaws 18 and 20 from the open position to the closed position. During an operation, tissue to be sealed is held between the jaws in the closed position for a predetermined time period, with pressure applied by the operator. In an embodiment of the present invention, the pressure exerted by the jaws on the tissue to be sealed is maintained using an actuation assistor.

Figures 3 to 7 illustrate the pair 16 of jaws 18 and 20. Figures 3 and 4 are perspective views of the jaws 18 and 20 in open and closed positions respectively, and Figures 5 and 6 are side views of the jaws 18 and 20, again in the open and closed positions respectively. Figure 7 shows a plan view of the jaws 18 and 20. The first jaw 18 extends from a proximal end 38 thereof to a distal end 40 thereof. Similarly, the second jaw 20 extends from a proximal end 42 thereof to a distal end 44 thereof.

The first and second jaws 18 and 20 have respective inner surfaces which face one another. The first jaw 18 carries a first electrode 24 on the inner surface thereof, and the second jaw 20 carries a second electrode 26 on the inner surface thereof. In the open position shown in Figures 3 and 5, the first and second electrodes 24 and 26 are spaced apart from one another. In the closed position shown in Figure 4 and 6, the first and second electrodes 24 and 26 are adjacent one another. Each of the first and second electrodes 24 and 26 may be provided by a single electrode, or by any suitable arrangement of a plurality of electrodes.

From the proximal end 38 of the first jaw 18 extends a first actuation member 28 which defines a first actuation slot 30. From the proximal end 42 of the second jaw 20 extends a second actuation member 32 which defines a second actuation slot 34. In the example shown, the first actuation member 28 extends outwardly of the second actuation member 32. The first and second actuation slots 30 and 34 are arranged to overlap one another, and extend at acute angles with respect to the longitudinal axis.

A jaw actuation pin 36 extends through the first and second actuation slots 30 and 34 of the first and second actuation members 28 and 32. The actuation pin 36 engages with the actuation members 28 and 32 in slidable contact. The actuation pin 36 is movable from a first position as shown in Figures 3 and 5 to a second position as shown in Figures 4 and 6. The first position of the actuation pin 36 corresponds to the open position of the jaws 18 and 20, and the second position of the actuation pin 36 corresponds to the closed position of the jaws 18 and 20. The actuation pin 36 is movable longitudinally with respect to the jaws 18 and 20 and the shaft 10 of the instrument 1. The movement of the actuation pin 36 within the first and second actuation slots 30 and 34 causes the jaws 18 and 22 rotate about the jaw pivot point 22. The actuation pin 36 engages with the actuation members 28 and 32 and drive those members between the open and closed positions. Moving the actuation pin 36 from the first position to the second position moves the jaws 18 and 20 from the open position to the closed position. Moving the actuation pin 36 from the second position to the first position moves the jaws 18 and 20 from the closed position to the open position.

Figure 7 illustrates the jaws 18 and 20 in plan view. As can be seen from Figure 7 the jaws extend from the proximal end 38, 42 to the distal end 40, 44, with a curved portion 46. The curved portion 46 curves to one side of a plane in which the actuation members 28 and 32 move. The curved portion 46, as is well known and understood, provides the operator of the instrument 1 with improved usability.

Figures 8 and 9 illustrate respective perspective and side cross-sectional views of the instrument of Figures 1 and 2. Figure 8 illustrates the instrument 1 in the open position, and Figure 9 illustrate the instrument 1 in the closed position. The main housing 4 of the instrument 1 provides an actuation grip pivot 50 on which the actuation grip 8 is mounted. The actuation grip 8 is able to rotate about the actuation grip pivot 50 under the control of the operator between the open and closed positions of the instrument 1. The actuation grip 8 is biased towards the open position by a resilient bias means, such as a spring. An actuation shaft 52 extends from the main housing 4 along the elongate shaft 10, through the passage therein, to the first and second jaws 18 and 20 at the distal end of the elongate shaft 10.

The actuation shaft 52 is attached to the actuation grip 8 by way of a shaft retaining portion 54. The shaft retaining portion 54 ensures that as the actuation grip 8 is rotated about the actuation grip pivot 50 that the actuation shaft 52 is moved linearly within the passage of the elongate shaft 10.

The actuation pin 36 is attached to the distal end of the actuation shaft 52. The actuation pin engages with the actuation slots of the first and second jaws 18 and 20, as described above, and is used to move the jaws 18 and 20 between the open and closed positions.

An actuation grip extension 56 extends from the actuation grip 8 at a position remote from the actuation grip pivot 52 the actuation grip extension 56 carries an actuation grip engagement portion 58, which, in this example, extends transversely with respect to the longitudinal axis of the instrument. An actuation assistor 60 is located in the fixed grip 6 of the instrument 1, and defines a receiving aperture 62 for receiving the actuation grip engagement portion 58 therein, when the instrument 1 is in the closed position. As illustrated in Figure 9, the actuation grip extension 56 extends into the fixed grip 6 when the instrument is in the closed position, such that the engagement portion 58 engages with the actuation assistor 60. The engagement portion is located in the receiving aperture 62 in the closed position.

In addition to the actuation shaft 52, a cutting blade 70 extends through the elongate shaft 10 from the main housing for of the instrument 1 to the distal end of the elongate shaft 10. A blade actuator 72 is rotatably mounted on a blade actuator pivot 74 located in the housing 4. The blade actuator 72 is attached to the blade 70 by means of a blade with tension portion 76, such that rotation of the blade actuator causes linear movement of the blade 70 along the longitudinal axis of the elongate shaft 10.

In operation, the operator of the instrument 1 holds the fixed grip 6 in order to position the jaws 18 and 20 at the appropriate point around a vessel to be sealed. The operator squeezes the actuation grip 8 in order to close the jaws 18 and 20 around the vessel to be sealed. The action of squeezing the actuation grip 8 causes the actuation grip 8 to rotate about the actuation grip pivot 50, thereby moving the shaft retention portion 54 along the longitudinal axis of the instrument 1 in a direction away from the distal end 14 of the elongate shaft 10. This movement of the shaft retention portion 54 causes the actuation shaft 52 to move along the elongate shaft 10 towards the main housing 4. The actuation pin 36 engages the actuation slots 28 and 34, thereby causing the jaws 18 and 20 to rotate into the closed position.

The actuation grip extension 56 is moved into the fixed grip 6, such that the actuation grip engagement portion 58 engages with the actuation assistor 60, and specifically with the receiving aperture 62 in order to retain the actuation grip 8 in the closed position. A resilient member 64 retains the actuation grip engagement portion 58 in the receiving aperture 62 until such time as the operator releases the actuation grip 8.

Whilst in the closed position, suitable electrical energy is supplied to the electrodes carried by the first and second jaws 18 and 20, so as to seal the vessel being gripped by the jaws 18 and 20. Once sealing has occurred, the actuation grip 8 can be moved by the operator to the open position so as to release the jaws 18 and 20 from around the vessel being sealed, thereby releasing the vessel.

Figures 10 to 15 illustrate embodiments of the present invention which include an actuation assistor 60 for the actuation grip 8 which removes the need for a double action when releasing the jaws 18 and 20 from the closed position. Each of the embodiments shown provides resilience between the engagement portion 58 of the actuation grip 8 and the actuation assistor 60.

Figures 10 and 11A to 11C illustrate a first such embodiment. In this first embodiment, the actuation assistor 60 is biased towards the main housing 4 by a resilient member 64. The actuation assistor 60 is shown in more detail in Figures 11A to 11B, which also illustrate the process of engaging the engagement portion 58 into the actuation assistor 60. The actuation assistor 60 includes a cam surface 82 which defines a first cam surface portion 84 and a second cam surface portion 88. The first cam surface portion 84 and the second cam surface portion 88 are contiguous, and define a cam highpoint 86 therebetween. The actuation assistor 60 is movable within the fixed grip 6 in the direction illustrated by arrow 61. This movement is caused by the insertion and retraction of the engagement portion 58 as the actuation arm 8 is moved from the open to closed position, and vice versa. The resilient member 64 is arranged to bias the actuation assistor 60 towards the pivot point 50 in the main housing 4, as indicated by arrow 65.

Figure 11A illustrates the position in which the engagement portion 58 enters the actuation assistor 60 and engages with the first cam surface portion 84. Since the actuation arm 8, and hence the engagement portion 58, rotates relative to the main housing 4 and fixed grip 6 about a fixed pivot point 50, the engagement portion 58 traverses a fixed radius path into the fixed grip 6 this fixed radius path is indicated by arrow 59 in Figures 11A to 11C. As the engagement portion traverses the path 59, the actuation assistor 60 is moved in a direction away from the pivot point 50 in the main housing 4, against the bias of the resilient member 64 (Figure 11 A).

When the engagement portion 58 reaches the highpoint 86 (Figure 11B), the actuation assistor 60 is at a maximum distance from the pivot point 50, and the resilient member 64 provides the highest bias force. As the operator continues to squeeze the actuation arm 8 so that the jaws 18 and 20 are held together by a desirable force, the engagement portion 58 continues to traverse the path 59 onto the second cam surface 88. The second cam surface 88 is arranged to allow the actuation assistor 62 move back towards the pivot point 50 thereby reducing the force applied by the resilient member 64. The engagement portion 58 then is able to be held in the second cam surface (which provides the receiving aperture 62) with a reaction force on the hand lower than that required to engage the jaws at the required closing force. The additional force provided by the engagement of the engagement portion 58 with the second cam surface 88 which is reacted by the resilient member 64 enables the desired closing force to be maintained. However, the operator of the instrument is able to relax their grip of the actuation arm 8 slightly. Such relaxation enables the operator to use the instrument in the closed position for longer, and also ensures that the force applied to the tissue between the jaws is unchanged during the vessel sealing operation. The engagement portion 58 is not, however, latched into place but is merely held by the second cam surface.

When releasing the instrument from the closed position to the open position, the engagement portion 58 traverses the path 59 in reverse to the direction just described. The highpoint 86 of the cam surface 82 provides an increased resilient force from the resilient member 64, but not does not require a double action to release as in the previously considered designs.

Figures 12, 13A and 13B illustrate a second embodiment of the present invention including a actuation assistor arrangement. The arrangement of Figure 12 is similar to that of Figure 10 in that the engagement portion 58 traverses a path 59 into and out of the fixed grip 6. In the second embodiment, the actuation assistor is provided by a resilient member 90 which has a first portion 92 and a second portion 96. The first and second portions 92 and 96 are contiguous and are joined at a high point 94. Similar to the first embodiment, the first and second portions 92 and 96 provide a cam surface along which the engagement portion 58 traverses. Instead of the cam surface being rigid and biased by a resilient bias member as in the first embodiment, in this second embodiment the cam surface is provided by the resilient member 90. The resilient member 90 may be of any suitable resilient material such as spring steel or equivalent. As the engagement member 58 moves along the path 59, the resilient member 90 is deflected away from the pivot point 50 in the housing 4 (Figure 13A) as shown by arrow 93. The deflection reaches a maximum as the engagement portion 58 passes the highpoint 94. At this maximum deflection, the resilient bias force offered by the resilient member 90 reaches a maximum. At the fully closed position (Figure 13B), the engagement portion 58 is held by the resilient bias force of the resilient member 90 in the second portion 96 which provides the retaining aperture 62.

As with the first embodiment, the engagement portion 58 then is able to be held with a force on the actuation arm 8 lower than that required to engage the jaws at the required closing force. The additional force provided by the engagement of the engagement portion 58 with the resilient member 90 enables the desired closing force to be maintained. However, the operator of the instrument is able to relax their grip of the actuation arm 8 slightly. Such relaxation enables the operator to use the instrument in the closed position for longer. The engagement portion 58 is not, however, latched into place but is merely held by the second cam surface. Figure 13B illustrates the final position of the engagement portion 58 and the resilient member 90 with the initial position of the resilient member 90 being shown by the dotted line 91. The resulting deflection of the resilient member 90 provides the required holding force for the engagement portion 58 in the second portion 96 of the resilient member 90.

When releasing the instrument from the closed position to the open position, the engagement portion 58 traverses the path 59 in reverse to the direction just described. The highpoint 94 of the resilient member 90 provides an increased resilient force, but once again not does not require a double action to release as in the previously considered designs.

Figure 14 illustrates a third embodiment having a resilient latch arrangement. In the third embodiment, the engagement portion 58 is attached to the actuation grip extension 56 by a resilient member 98 which allows the engagement portion 58 to move with respect to the actuation grip 8 and to be biased in a direction away from the pivot point 50. Figures 15A, 15B and 15C illustrate the latch arrangement and the process of latching the engagement portion 58 in accordance with the third embodiment.

According to the third embodiment, the actuation assistor comprises a body portion 100 which defines first and second cam surfaces 102 and 106. The first and second cam surfaces 104 and 106 are contiguous and meet at a highpoint 104. In contrast with the first and second embodiments, in the third embodiment the cam surface is fixed with respect to the fixed grip 6. The actuation grip extension 56 rotates about the pivot point 50 along a fixed radius indicated by arrow 57. The engagement portion 58 is resilient the attached to the extension 56, and so is able to move with respect to the extension 56. Accordingly, as the actuation grip 8 is squeezed by the operator to move the jaws from the open position to the closed position, the engagement portion 58 is able to follow the first cam surface 102 (Figure 15A), whilst compressing the resilient member 98. This compression of the resilient member 98 provides a bias force for the engagement portion 58 against the cam surface 102. Upon reaching the highpoint 104 (Figure 15B) this bias force reaches a maximum, and as the grip 8 is squeezed further, the engagement portion 58 engages with the second cam portion 104 (Figure 15C).

As with the first and second embodiments, the engagement portion 58 then is able to be held with a force on the actuation arm 8 lower than that required to engage the jaws at the required closing force. The additional force provided by the resilient member 98 enables the desired closing force to be maintained. However, the operator of the instrument is able to relax their grip of the actuation arm 8 slightly. Such relaxation enables the operator to use the instrument in the closed position for longer. The engagement portion 58 is not, however, latched into place but is merely held by the second cam surface.

When releasing the instrument from the closed position to the open position, the engagement portion 58 traverses the path 59 in reverse to the direction just described. The highpoint 104 causes the resilient member 98 to provides an increased resilient force, but once again not does not require a double action to release as in the previously considered designs.

Accordingly, embodiments the present invention are able to provide bipolar surgical instruments is able to provide a constant jaw closure force during vessel sealing without the need to latch the handle in place and thus requiring a two-stage release process.

Claims

CLAIMS:

1. A bipolar surgical instrument comprising:

a body;

a fixed grip which extends from the body;

an elongate shaft attached to, and extending from, the body, the shaft extending to a distal end;

first and second opposed jaws located at the distal end of the shaft, the first jaw being movable with respect to the second jaw between an open position in which the first and second jaws are spaced apart from one another, and a closed position in which the first and second jaws are adjacent one another;

an actuation shaft connected with at least the first jaw, the actuation shaft being movable with respect to the body and the shaft between a first position in which the jaws are in the open position, and a second position in which the jaws are in the closed position;

an actuation grip movably mounted on the body, and arranged to operate the actuation shaft, the actuation grip having a released position in which the actuation shaft is in the first position, and an engaged position in which the actuation shaft is in the second position;

a bias element arranged to bias the actuation grip towards the released position with an actuation grip return force; and an actuation assistor located in the fixed grip and arranged to hold the actuation grip in the second position with a predetermined force greater than zero and less than the actuation grip return force.

2. An instrument as claimed in claim 1, wherein the actuation grip is mounted on a pivot point for rotation with respect to the body and fixed grip, the actuation grip being rotatable about the pivot point between the released and engaged positions.

3. An instrument as claimed in claim 2, wherein the actuation assistor includes a cam surface, and the actuation grip includes an engagement portion which movably engages the cam surface within the fixed grip, the cam surface defining a receiving aperture for receiving the engagement portion therein when the actuation grip is in the second position, the receiving aperture being shaped so as to hold the engagement portion with the predetermined force.

5

4. An instrument as claimed in claim 3, wherein the actuation assistor is slidable with respect to the fixed grip and is resiliently biased towards the pivot point, and wherein the engagement portion is fixed relative to the actuation grip.

5. An instrument as claimed in claim 4, wherein the actuation assistor is biased by a resilient member fixed at one end to the fixed grip.

6. An instrument as claimed in claim 4, wherein the actuation assistor is provided by a resilient member which extends into the fixed grip.

7. An instrument as claimed in claim 3, wherein the actuation assistor is fixed with respect to the body, and wherein the engagement portion is movable and resiliently biased relative to the actuation grip.