WO2014027064A1

WO2014027064A1 - An electrosurgical pencil with a switch means

Info

Publication number: WO2014027064A1
Application number: PCT/EP2013/067082
Authority: WO
Inventors: Jesper Schantz Simonsen
Original assignee: Safeair Ag
Priority date: 2012-08-15
Filing date: 2013-08-15
Publication date: 2014-02-20

Abstract

The invention provides an electrosurgical pencil with a switch for controlling power from a connected generator. To facilitate the use of the pencil and switching of the switch, the invention provides a pencil where the switch has an actuator providing two push buttons formed by one and the same piece of an elastically deformable material.

Description

AN ELECTROSURGICAL PENCIL WITH A SWITCH MEANS

INTRODUCTION

The present invention relates to an electrosurgical pencil adapted to be connected to a generator capable of supplying electrosurgical cutting energy for cutting tissue and electrosurgical coagulation energy for coagulation of tissue during surgery. The pencil comprises an elongated body, an exposed electrode located at a distal end of the elongated body, and a switch means for switching between the electrosurgical cutting energy and the electrosurgical coagulation energy.

BACKGROUND OF THE INVENTION In electrosurgery, high frequency (radio-frequency) current is applied by an active electrosurgical electrode to cause a cutting action, hemostasis, or coagulation of bleeding tissue. Typically, the surgeon switches between two levels of energy, one being for cutting and one being for coagulation of the tissue. The switching is carried out by use of a foot operated switch or by use of a switch on the body of the tool which is in the hand of the surgeon.

There remains a need within the art for improved ways of switching between the energy level in electrosurgical cutting and coagulation instruments.

SUMMARY OF THE INVENTION

To overcome problems with operating the existing pencils, the invention provides an electrosurgical pencil where the switch means comprises:

- at least two first electrical contacts having at least one first main body part configured as at least one first conductive sheet component,

- at least one second electrical contact having at least one second main body part configured as at least one second conductive sheet component, wherein the first electrical contacts and the at least one second electrical contact are provided superjacent and spaced apart - an actuator comprising a button means including a first actuator button above one of the first electrical contacts and a second actuator button above the other one of the electrical contacts such that that a selected one of the first electrical contacts can be pressed against the second electrical contact in response to a force applied to a respective one of the first and second actuator buttons. The first and second actuator buttons are formed in a single piece of an elastically deformable material allowing movement of one of the actuator buttons independently from the other actuator button.

Due to the elastic deformable, single piece actuator, the button becomes more easily operable, and particularly for the surgeon who must concentrate on the cutting or coagulation process, the one piece elastically deformable switch becomes easy to operate without having to look at the actuator. Particularly, the surgeon may keep one finger constantly on the single piece while moving the finger along the piece between the two actuator buttons. During operation, the elastic deformability enables actuation of one of the buttons without influencing the position of the other button which again facilitates an easier operation of the switch.

Within the context of the present invention the term "actuator" is used for the mechanical part of the electrosurgical instrument used to apply a force to the at least one first electrical contacts, so that the first electrical contacts come to touch the at least one second electrical contact. The term "switch means" is within the context of the present invention used for the part of the electrosurgical instrument that is used to control delivery of the electrical power from the generator to the elongated electrosurgical instrument in response to operating an actuator. The switch means can open and close an electrical circuit between one of the first electrical contact and the at least one second electrical contact to supply current or interrupt current from an electrosurgical generator to the exposed electrode. The term "contact" is used for the parts of the switch means that are touches to complete an electrical circuit between the at least one first electrical contact and the at least one second electrical, and separate to open the electrical circuit between the at least one first electrical contact and the at least one second electrical contact. Within the context of the present application the term "sheet component" refers to a component having a main portion or main body part that is very thin in comparison to its length and width. Sheet components may preferably have thicknesses between 0,1 mm and 0,5 mm. The single piece may particularly form two wings and an interface between the two wings. Each of the two wings may form one of the first and second actuator buttons, and the wings may extend in opposite directions from the interface. The interface may be rigidly fixed to the elongated body of the pencil, and a transition portion between the interface and each wing may facilitate bending of the wings relative to the interface.

The transition portions between the interface and the wings may e.g. be constituted by a portion of the single piece of an elastically deformable material which is relatively thin compared to the general thickness of the wings, or it may be constituted by a different or more easily elastically deformable material. This may facilitate that the bending stiffness in a direction towards the body may become low compared with the bending stiffness of the other parts of the single piece of an elastically deformable material. Accordingly, the wing may pivot about the transition portion relative to the interface.

Particularly, the single piece may be an element constituted by one or more distinctive materials moulded, glued, welded or otherwise assembled to become unitarily bonded and appearing as one single piece. Particularly, it may be moulded in one piece by injection moulding.

An oblong stem may extend from each wing towards one of the first electrical contacts. The stem may facilitate a firm push against the first electrical contacts and thus ensure improved functioning. The stems and wings may be made from the same material e.g. in one piece, or the stems may be made from a more rigid and therefore less easily elastically deformable material. By "one piece" is herein meant that it is uniform or monolithically formed, i.e. essentially without distinctive or visible transitions between different elements or different materials.

When applying a pressure to one of the first or second actuator buttons, the transition to the corresponding wing becomes deformed and the wing bends downwards in the direction towards the corresponding one of the first electrical contacts.

To provide a home-position towards which the actuator buttons will return upon release of the pressure on the actuator button, the switch means may comprise at least one membrane acting on each stem. As an example, the membrane may be stretched between the body and the aforementioned stem, e.g. such that the stem extends upwards both from a forward and an opposite rearward surface of the membrane. When the actuator button is pressed towards the first electrical contact, the membrane becomes stretched, and when the pressure is released, the membrane returns to its original shape thereby lifting the actuator button away from the first electrical contact. At least one of the interface and membrane, and possibly the entire single piece of an elastically deformable material may be formed in one piece with at least a portion of the body, e.g. in the same material or in two different materials, e.g. by use of a two-component injection moulding technique. Particularly, the membrane and the wings may be formed in a material which is more elastically deformable than the material by which the elongated body is formed.

The membrane may form a liquid tight seal into a compartment which houses the electronic components of the pencil, later referred to as first compartment. In that way, the membrane serves both to bias the switch means towards a home state where the contacts are open and serves to form a liquid tight encapsulation of electric parts, thereby protecting against ingress of moist etc.

In one embodiment the single piece of an elastically deformable material and at least a part of the elongated body of the pencil is formed in one piece, e.g. by 2-component-injection moulding, or by adhesive assembling. By this feature, ingress of moist and escape of gas during surgery can be reduced or completely prevented.

The first conductive sheet component and the second conductive sheet component are arranged "superjacent" each other and spaced apart. Accordingly, the sheet components are provided immediate above each other such that physical contact between the sheet components depends on the state of the contacts, i.e. out of direct physical contact in the open state of the contacts, but so that the distance between the first conductive sheet component and the second conductive sheet component can be reduced to close the contacts, e.g. by pressing the first sheet components towards the second sheet components.

The sheet components can e.g. be made of a sheet material that can deflect and/or yield in response to application of a force by virtue of the inherent properties of the selected material alone, additional designing and or combinations of these properties.

Any of the first electrical contact and the at least one second electrical contact can preferably be obtained by punching, stamping, blank cutting or laser cutting the first sheet component and/or the second sheet components, or by using combinations of these methods, whatever is the most convenient and the least expensive for a given material, and given situation and a certain instrument. Small sheet component are objects that can be made fast, in large numbers, in a continuous manufacturing process, and can be stored without making extraordinary precautions regarding storage conditions. However any other simple method that is feasible for separating out small thin substantially flat objects in large numbers from a larger, thin sheet material are contemplated within the scope of the present invention. The flat thin, layered structure of the switch means according to the present invention may in the following be referred to as a "stamped circuit" (SC). This expression should however not be construed as limiting the scope of the present invention, since, as explained above, the first and second conductive sheet components can be made using many other methods than stamping. Thus the term "stamping" is to be understood to cover methods for separating small sheet components with flat main bodies from a blank of a sheet material for use as the conductive sheet components.

An SC can be made of metal, e.g. aluminium, as well as of conductive non-metals like conductive polymers. In order to further ensure that the at least one first conductive sheet component and the at least one second conductive sheet component maintain out of electrical contact when the switch means is open, an insulating insert can be provided between the at least one first electrical contact and the at least one second electrical contact except on at least one area left free of insulating insert for allowing the at least one first electrical contact and the at least one second electrical contact to get in contact with each other, i.e. to obtain the closed state of said contacts. The actuator buttons are provided in relation to the free area in order to obtain the required electrical contact between the first and the second electrical contacts to close the circuit and supply energy to the exposed electrode.

In one embodiment, the two first electrical contacts are provided in substantially the same first plane superjacent a second plane in which the at least one second electrical contact is located.

Two different spaced apart first electrical contacts may for example be used for activating cutting voltage and coagulating voltage, respectively. Voltages can then be applied over any of the respective two first conductive sheet components and the at least one second conductive sheet component when any of the at least two first conductive sheet components physically contact the at least one second conductive sheet component, and thereby closes the circuit between said first conductive sheet component that has been operated by the actuator, e.g. have been pressed down by the actuator, and the at least one second conductive sheet component. The closed circuit can e.g. be registered by a suitable meter, e.g. an amperemeter or voltmeter. If the meter registers that the pressed down first conductive sheet component corresponds to cutting, a cutting voltage will be sent through the at least one second conductive sheet component and through the exposed electrode to the surgical site. If the meter registers that the pressed down first conductive sheet component corresponds to coagulating, a coagulating voltage will be sent through the at least one second conductive sheet component and through the exposed electrode to the surgical site.

An embodiment wherein at least two first electrical contacts are provided in substantially the same plane superjacent the plane of the at least one second electrical contact facilitates use of the same actuator for switching between cutting and coagulation modes of the elongated electrosurgical instrument as well as the switch means can be made very thin. The first electrical contacts in form of conductive sheet components are just placed next to each other in the same plane below the actuator.

When the first actuator button or second actuator button are pressed down or otherwise brought in contact with the raised or projecting contact parts of the at least one first conductive sheet component, the operation of the actuator buttons serves to displace the raised or projecting contact parts towards the at least one second conductive sheet component so that the at least one first conductive sheet component and the at least one second conductive sheet component make contact and close the circuit between the at least one first electrical contact and the at least one second electrical contact.

If the switching operation between the open state and the closed state of the at least one first electrical contact and the at least one second electrical contact is tactile, the surgeon can obtain inherent and immediate information of his/hers actuation and manipulation of the switch means. The electrosurgical instrument may advantageously comprise two individual first conductive sheet components, one constituting a first one of the first electrical contacts and the other constituting a second one of the first electrical contacts. The instrument may comprise: a first electric wire that is connected to the first one of the first conductive sheet components. This could be actuated in a cutting mode of the electrosurgical instrument, a second wire that is connected to the second one of the first conductive sheet components. This could be actuated in a coagulation mode of the electrosurgical instrument, and a third electrical wire that is connected to the second conductive sheet component and through which cutting voltage or coagulation voltage is applied to the electrode when a respective one of the first conductive sheet components is actuated by operating the actuator. Thus in simple manner switching between cutting and coagulation mode can be registered and controlled. The electrosurgical generator may include means for determining if the cutting circuit or the coagulation circuit is closed. The registration of this event may be used to trigger the correct level of voltage to the exposed electrode. A means for determining whether or not two opposite first and second electrical contacts are in a closed state can preferably be integral with the electrosurgical generator, e.g. a voltmeter that measures voltage difference between the third wire and the first wire or between the third wire and the second wire.

The single piece of an elastically deformable material or just the first and second actuator buttons could be made e.g. from silicone, abs or TP. The two actuator buttons could e.g. be made from the same or from different kinds of elastically deformable material.

DETAILED DESCRIPTION

The invention will be described in further details below with reference to the drawing, in which exemplary embodiments are shown in accordance with the present invention. Fig. 1 shows a perspective top view of a first embodiment of an elongated electrosurgical instrument according to the present invention, fig. 2 shows the elongated main body, the electrode, and the switch means in an exploded, enlarged scale perspective view, fig. 3 shows the tubular part of the first embodiment shown in fig. 1 in a perspective view seen from below, fig. 4 is a sectional view of the elongated main body shown in fig. 1 taken along line IV-IV illustrating the joining of the tubular part and the cover part, but without the cable, fig. 5 shows an exploded, perspective view of the switch means and a fragment of an associated cable, fig. 6 shows an enlarged scale view of the switch means in assembled state with an actuator arranged above, fig. 7 shows a perspective view seen inside the cavity of the cover part, wherein the switch means and the exposed electrode has been inserted, fig. 8 is a top view of the cover part, fig. 9 is a view inside the elongated cavity of the cover part provided with the actuator, fig. 10 shows the cover part seen from the side, fig. 11 shows a second embodiment of an actuator for use with the present invention, fig. 12 shows the actuator seen directly from a short side, to illustrate the stems of the actuator buttons, and figs. 13-15 illustrate an alternative embodiment of an actuator.

The electrosurgical instrument and switch means according to the present invention is described in further details below by way of exemplary embodiments. The electrosurgical instrument and switch means are versatile and the components of the electrosurgical instrument and switch means can be combined into a plurality of electrosurgical instrument having different properties, functionalities and designs.

Below, selected embodiments are described as examples only, of the many ways the components can be combined into various electrosurgical instruments for various purposes. Functionality and design of the electrosurgical instrument can be changed either at the manufacturing stage or by the surgeon in advance of, or in relation to the surgical procedure, as will be understood by the following description. Thus, electrosurgical instruments comprising other combinations and arrangements of the inventive components, such as e.g. actuators, first and second coupling parts, providing the cable for connecting to the electrosurgical generator outside and/or inside the suction tubing, kinds of electrodes, and shapes of the elongated main body, and how these components are combined are also intended within the scope of the present invention.

Fig. 1 shows a perspective view, seen from an actuator side, of a first embodiment of an elongated electrosurgical instrument 1 according to the present invention. The electrosurgical instrument 1 is of the kind configured for at least cutting and coagulating tissue of a patient during surgery by application of electrical energy supplied from an electrosurgical generator (not shown) to a surgical site (not shown).

The electrosurgical instrument 1 comprises a hollow elongated body 2, an exposed electrode 3 in the form of a blade electrode 3, an actuator 4 for manual application of a force to a switch means 5 below the actuator 4, which switch means 5 is incorporated inside the elongated main body 2 and thus not visible in fig. 1. A suction tip 6 is mounted at a first end

7 of the elongated main body 2 to surround the blade electrode 3 as well as a first suction port 40 (not visible in fig. 1). A first embodiment of a first coupling part 8 is inserted into a second end 9 of the elongated main body 2 opposite the first end 7, which first coupling part

8 serves as an intermediate member for connecting the second end 9 of the elongated main body 2 to a first end 10 of a flexible suction tubing 11, in the present case e.g. of disposable transparent plastic material. A cable 12 is connected to the switch means 5 to deliver current from an electrosurgical generator (not shown) to the blade electrode 3 in response to actuation of the actuator 4.

In the present embodiment of the electrosurgical instrument 1 the cable 12 extends inside the suction tubing 11 towards a second end 13 of the suction tubing 11, at which second end 13 a second coupling part 14 is mounted in order for said suction tubing 11 to be

appropriately coupled to a vacuum source (not shown) . In other embodiments the cable 12 can extend exterior to the suction tubing 11.

The structure and design of the elongated main body 2 is seen more clearly in the exploded, perspective, enlarged scale view of fig. 2.

The first end 7 of the elongated main body 2 has a first opening 15 into which the exposed electrode 3, in the present case the blade electrode 3, can pass, to be mounted to the elongated main body 2, thus the combined tubular part 16 and cover part 17, in conductive communication with the switch means 5, optionally in a replaceable manner, so that the surgeon can arrange the angle of the blade electrode 3 in relation to the main body 2, as desired, or replace the blade electrode 3 with another kind of electrosurgical electrode.

The elongated body 2 includes two main components, a tubular part 16 and a cover part 17 respectively, which parts 16,17 preferably are manufactured as individual parts which are joined, e.g. by heat sealing, in order to create the elongated main body 2, once all electrosurgical components relevant for the instrument's performance, such as switch means and wires, are mounted appropriately. The tubular part 16 and the cover part 17 may be manufactured by any suitable kind of moulding method and subsequently joined. A wall 18 of the cover part 17 has a substantially semi-circular cross-section for providing, inside the elongated body 2, space for accommodating both the switch means 5 and at least the part of the actuator 4 that serves to engage said switch means 5. The actuator 4 protrudes beyond the outermost circumference of the wall 18 of the cover part 17 - just sufficiently for the surgeon to be able to actuate the switch means 5 by using the actuator 4. The actuator 4 does not extend into the tubular part 16. The tubular part 16 defines a suction channel 27, and the particularly low profile obtained by use of sheet components for the switch means allow a relatively large cross section of the suction channel. In this way the overall exterior appearance of the first embodiment of the electrosurgical instrument 1 is kept elegant and slim in order not only to be easy to handle, but also to preserve a design of the electrosurgical instrument that allows said instrument to be introduced through a very small surgical incision, while at the same time obtaining an electrosurgical instrument with high suction efficiency. Other cross-sections of cover parts 17 may be appropriate too. The cover part 17 may thus be made without a perfect semi-circular cross-section, e.g. be made more flat.

The wall 18 of the cover part 17 also has a first aperture part 19, through which a first actuator button 20 for application of a cutting voltage can pass in order to actuate the cutting mode of the switch means 5, and a second aperture part 21 through which a second actuator button 22 for application of a coagulation voltage can pass in order to actuate the switch means 5 in a coagulation mode of the switch means 5. An exterior side 23 of the wall 18 of the cover part 17 has protruding ribs 24, barbs or other tactile means adjacent the first aperture part 19 and the second aperture part 21.

At the first end 7 of the elongated main body 2, both the cover part 17 and the tubular part 16 have opposite facing similar circumferential engagement means 25, e.g. an external thread or spaced apart circumferentially protruding beads, for securing the suction tip 6 in adjustable manner in selected suction position in relation to the longitudinal axis of the elongated main body 2, as shown in fig. 1. A stop web 26 defines an end position of the suction tip 6 on the elongated main body 2. Due to the stop web 26 the suction tip 6 cannot be accidentally pushed too far against the actuator 4 when adjusting the suction position of the suction tip 6. The closer the suction tip 6 gets to the stop web 26 the more of the exposed electrode, in the present case the blade electrode 3, is exposed from the suction tip 6. In this way the surgeon is able to choose the distance between the tip of the blade electrode and the suction opening of the suction tip.

The tubular part 16 constitutes a second elongated compartment 27 of the hollow elongated main body when the tubular part 16 is assembled with the cover part 17. The tubular part 16 has a substantially semi-circular exterior wall part 28, which circumferentially merges into an elongated wall part 29 having a substantially flat base 30. The base 30 of the wall part 29 becomes the partition wall 30 of the elongated main body 2 when assembled with the cover part 17. The wall part 29 seals the second compartment 27 from the surroundings to allow the second compartment 27 to serve as the suction channel 27. The partition wall 30 has guide pins 31 projecting away from the suction channel 27, for arranging the switch means 5 in the correct position in relation to the elongated main body 2, e.g. as shown in fig. 2, closer to the first end 7 of the elongated main body 2 than to the second end 9 of said elongated main body 2. A cable trap 32, defined by a tortuous path for the cable 12, is provided on the partition wall 30 between the second end 9 of the elongated main body 2 and the projecting guide pins 31 for the switch means 5. The cable trap 32 serves to secure the cable 12 firmly inside the electrosurgical instrument 1 to prevent it from being teared off so that electrical connection to the switch means 5 accidentally is lost, e.g. when the surgeon uses the electrosurgical instrument 1. Between the guide pins 31 and the first end 7 of the elongated main body 2 the tubular part 16 has a holder 33 for securing the blade electrode 3, which blade electrode 3 has a conductive coupling rod 34 that extends into a conductive electrode tip part 35 via a conductive securing part 36. The conductive securing part 36 includes a first engagement part 37 of first pentagonal cross-section, which first engagement part 37 is provided opposite a coupling end 39 of the coupling rod 34.

As is seen more clearly in fig. 3, the tubular part 16 has the first suction port 40 arranged facing the exposed electrode 3 opposite a second suction port 41 at the second end 9 of the elongated main body 2.

A switch means 5 to be provided on the partition wall 30 of the tubular part 16 of the elongated main body 2 is arranged for supplying the electrical energy to the exposed electrode 3 in response to operating the actuator 4 above the switch means 5.

The switch means 5 has a first electrical contact 42, another first electrical contact 43 out of physical contact with the first electrical contact 42, and a second electrical contact 44 superjacent the first electrical contacts 42, 43. Thus there is a very small distance between the plane of the first electrical contacts 42, 43 and the plan of the second electrical contact 44 in the assembled state of the switch means 5, which distance defines a gap into which an insulating insert 45 is provided to prevent unintended closure of circuits and diverted current flow.

The first electrical contact 42 is activated for application of a cutting voltage by means of the first actuator button 20, and the other first electrical contact 43 is activated for application of a coagulation voltage by means of the second actuator button 21. Both first electrical contacts 42,43, the second electrical contact 44, and the insulating insert 45 has holes 46 for receiving the protruding, confronting guide pin 31 on the partition wall 30. In this way the switch means 5 can in a very simple and fast manner be built on the partition wall 30 by stacking the very few individual components of the switch means on top of each other on the partition wall 30, connecting the cable 12 appropriately to put the switch means 5 into electrical contact with the exposed electrode 3, and enclose the switch means 5 by arranging the cover part 17 on top of the tubular part 16 to define a first compartment 59a, as seen in figs. 4 and 18, where inside the first compartment 59a, the cable 12 for establishing electrical communication between the switch means 5, the exposed electrode 3 and the electrosurgical generator, extends.

By proper dimensioning of the holes 46 in the electrical contacts 42, 43, 44 and the diameter of the guide pins 31 on the partition wall 30, individual distances between the first electrical contacts 42, 43, and well-defined gaps between any of the first electrical contacts 42, 43 and the second electrical contact 44 can be defined in a simple manner. Tapered guide pins 31 can e.g. only pass through the hole 46 just to the extent where the tapered guide pin's 31 diameter's and the hole's diameter's are the same. Simply by making larger holes 46 in the second electrical contact 44, said second electrical contact 44 is able to receive e.g. the full length of the guide pins 31, while smaller holes 46 in the first electrical contacts 42,43 serve to preserve the required insulation distance between any of the first electrical contacts 42,43 and the second electrical contact 44 without the absolute requirement of inserting the insulating insert 45, although such an insulation insert 45 is preferred in most embodiments. The lateral distance between the two first electrical contacts 42, 43 is obtained by corresponding suitable allocation of the guide pins 31 across the partition wall 30.

Fig. 4 is a cross-sectional view taken along line IV-IV in fig. 1 shown without the cable 12 or any other component inside the cover part 17 to better illustrate the size of the

compartments. The suction channel 27 is the second compartment 27 of the tubular part 16, and the first compartment 59a is created when a cavity 59 of the cover part 17 is placed arching the partition wall 30 of the tubular part 16. Due to the partition wall 30, all electronic components can be kept inside the first compartment 59a isolated from the large suction flow pathway 27. The unobstructed large cross-section of the suction channel 27 provides a very high flow velocity and therefore confers high suction performance to the electrosurgical instrument according to the present invention.

Fig. 5 is an exploded perspective view of the switch means 5, which was shown in assembled state in fig. 2, and is seen in the perspective view in fig. 6 with the actuator arranged aligned above.

The first electrical contact 42 has a first main body part 47 configured as a first conductive sheet component 47, the other first electrical contact 43, i.e. the second first electrical contact 43 has a second first main body part 48 configured as a second first conductive sheet component 48. The second electrical contact 44 has a second main body part 50 configured as a second conductive sheet component 50. The second conductive sheet component 50 has an electrode contacting end 51 with an electrode connection terminal 52 for securing the exposed electrode 3, and an opposite cable connection end 53 with a third wire connection terminal 54. The electrode connection terminal 52 is configured as a clamp 52 to fittingly engage the conductive coupling rod 34 of the blade electrode 3. The conductive coupling rod 34 is inserted into the electrode connection terminal 52 of the second conductive sheet component 50 to establish electrical contact to the conductive blade electrode tip 35. In the present embodiment the electrode connection terminal 52 is illustrated as a clamp, however other designs are foreseen within the scope of the present invention.

The third wire connection terminal 54 is used for securing a third 12c of three wires of the cable 12 so that the correct voltage can be supplied to the exposed electrode 3 from an electrosurgical generator in response to a measurement of an electrical parameter representing an identification of which actuator buttons 20,22 that have been actuated. To that aspect the first 42 of the first electrical contacts 42,43 has a first wire connection terminal 55 for securing a first 12a of three wires of the cable 12, and the second 43 of the first electrical contacts 42,43 has a second wire connection terminal 56 for securing a second 12b of three wires of the cable 12. In the present case the cable 12 is a Schneider cable, where the conductor insulation is penetrated once the wire is introduced in a respective wire connection terminal.

The first conductive sheet component 47 of the first 42 of the first electrical contacts 42,43 has a raised or projecting contact part 57, and the second first conductive sheet component 48 of the second 43 of the first electrical contacts 42,43 has a raised or projecting contact part 58. The insulating insert 45 has actuating apertures 49a, 49b, to allow passage of the aligned selected raised or projecting contact part 57,58 of the respective first electrical contacts 42, 43 towards the second conductive sheet component 50 in response to a force application on the similarly aligned respective actuator button 20, 21. When a raised or projecting contact part 57, 58 touch the second conductive sheet component 50, a circuit is closed so that current of a voltage level related to the actuated actuator buttons 20,21 can flow from the electrosurgical generator to the conductive blade electrode 3 via the cable 12.

No expensive optical switches or thick and complex PCB's are required. The use of simple, thin, substantially flat stacked conductive sheet components makes it possible to create a switch means 5 that appear considerable flatter than known switch means used in conventional electrosurgical instruments for similar purposes. The conductive sheets components 47, 48, 50 used in the inventive switch means 5, can easily be stamped, punched or cut from a thin plate, e.g. a plank of metal. The holes for the guide pins and cutting of slits to make the raised parts can be made in the same process step. Wire connection terminals and the terminal for the exposed electrode can be made by subsequent or simultaneous bending or folding. In the exemplary embodiment of the switch means 5 shown in figs. 2, 5 and 6 the first 42, 43 electrical contacts have bended sides or walls, that facilitates fitting of the first electrical contacts 42, 43 on the partition wall 30. Bended sides or walls are expedient when placing the sheet components on the partition wall, however not mandatory features of the first electrical contacts 42, 43, but can if desired be made in the same bending process as the terminals 55,56. In case further electrical functionalities in addition to cutting and coagulation is desired implemented in the electrosurgical instrument 1 according to the present invention, more than two first electrical contacts can be included in the switch means 5, and the actuator 4 can be adapted accordingly, at minimal further costs. For example, it is possible to make an electrosurgical instrument where the surgeon is able to switch between more than two voltage levels by using easy accessible buttons on the instrument instead of reaching to the electrosurgical generator simply by including an inexpensive further first electrical contact and wiring in the switch means, and corresponding actuator button.

In fig. 6 the switch means 5 is illustrated with the actuator 4 arranged above so that the actuator buttons 20, 22 are aligned with the raised or projecting parts 57, 58 (only the raised part 57 is visible in Fig. 6). The actuator 4" is formed in as one single element including wings 73, 74 each forming one of the first and second actuator buttons 20, 22.

The interface 75 is located between the wings and it is joined with elongated body of the pencil. The disclosed actuator further comprises a membrane 79 which intersects the stems (not shown) and facilitates biasing of the buttons towards a home position where the switching means is open.

The wings 73, 74 are joined to the interface via transition portions 77, 78 in which the bending stiffness in a direction towards the body is lower than the bending stiffness of the remaining portion of the wing. This is facilitated by a reduced wall thickness of the material at the transition portions as compared to the thickness of the wings 73, 74. The buttons, the wings, the interface and the membrane are made in one single piece by injection moulding of a polymer material which is elastically deformable, e.g. silicone.

Fig. 7 is a fragmentary perspective view inside the elongated opening or cavity 59 of the cover part 17 of the elongated main body 2. The switch means 5 is inserted in the cover part 17 and seen from a bottom side 60 of the second electrical contact 44. The electrode connecting terminal 52 protrudes towards the first end 7 of the elongated main body 2's cover part 17, and the coupling rod 34 of the blade electrode 3 is clamped into said electrode connecting terminal 52, while the remainder of the exposed electrode 3 extends through the holder 33 of the tubular part 16 when joined with the cover part. The switch means 5 is isolated from the suction channel and cannot get into contact with sucked matter from the surgical site. Appropriate sealing can e.g. be obtained by providing a sealing material 62 at a conductive transition 61 between the electrode connecting terminal 52 and the second conductive sheet component 50. The sealing material 62 can e.g. be provided during the process of heat-sealing the cover part 17 together with the tubular part 16. The sealing material 62 can also be provided as a transverse wall or a sealing part distal to or around e.g. the conductive transition 61. The insulation material 62 can be of the same or other plastic material as used for the elongated main body 2.

The cavity 59 of the cover part 17 has a first cable guide member 63 disposed a short distance from the second end 9 of the cover part 17 of the elongated main body 2. Proximal to the first cable guide member 63 said second end 9 is designed to receive the first coupling part 8 for providing communication to the vacuum source. In order for the cable 12 to pass smoothly without kinks inside the cover part 17 a second cable guide member 64 is made integral with the wall of the cover part 17 proximal to the first cable guide member 63. One or both of the cable guide members 63, 64 can be left out if expedient or more cable guide members be included if necessary.

The elongated edges of the circumferential wall 18 of the cover part 17 has respective coupling webs 65a, 66a to mate with complementary coupling webs 65b, 66b, as seen in fig. 2, on the tubular part 16 when tubular part 16 and cover part 17 are joined to create the double-lumen elongated main body. A plurality of distance members 67 is distributed inside the cavity 59 along the elongated sides. They serve to locate the tubular part 16 on the partition wall 30 and to enforce the joined structure 16, 17 and provide structural stability to the elongated main body 2.

An alternative method of joining the tubular part 16 and the cover part 17 could be gluing, however combinations of methods are within the scope of the present invention. Glue can be applied if considered expedient at any surfaces, such as e.g. at any of the coupling webs 65a, 66a, the complementary coupling webs 65b,66b and the distance members 67.

Fig. 8 is a top view of the cover part 17. The actuator 4 is illustrated with different designs of actuator buttons 20, 22. The differences in designs help the surgeon to identify the correct button, and thus serve as a safety means for application either cutting voltage or coagulation voltage. In the view of the cover part 17 seen in fig. 9 the switch means has been left out, so that stems 68,69 of the first actuator button 20 and the second actuator button 22, respectively, can be seen. When the free ends of the stems 68,69 are forced towards the raised parts 57,58 of the first conductive sheets components 47,48 towards the second conductive sheet component 50 a circuit is closed and current allowed to flow to the exposed electrode, as previously described.

Fig. 10 shows the cover part seen from the side and how the stems 68, 69 pass through respective first 19 and second 21 aperture halves. The very limited extent of projection of the actuator 4 from the wall 18 of the cover part 17 is due to the very flat switch means 5 that gives the electrosurgical instrument 1 a very streamlined appearance and small largest diameter. The actuator 4 is of the kind that has a single piece of an elastically deformable material which forms two wings, each forming one of the buttons 20, 22, and an interface 70, which is joined to the elongated body, or more exactly to the cover part 17 of the elongated body. Fig. 11 illustrates an embodiment of an actuator for a pencil according to the invention.

The actuator 4' is made as a single piece of an elastically deformable material allowing movement of one of the actuator buttons independently from the other actuator button. Each button is formed by a wing which is joined via transition portions 77, 78. The transition portions are constituted by a thin and elastically deformable sheath of a rubber material allowing movement of one of the actuator buttons independently from the other actuator button.

The actuator buttons 20', 22' are provided with respective stem 68', 69'. The buttons 20', 22' has different height and surface texture and/or surface to enable the surgeon to identify the relevant button without having to look at the buttons. Since the at least one first electrical contact can be forced against the second electrical contact no further mechanical or electrical components are required to close contacts. The part of the actuator that shall be accessible from outside the elongated main body can be kept inferior or be entirely eliminated without affecting the high suction properties. In fact the switch means are so flat and thin that the first compartment also has sufficient radial space for accommodating the thickness of the actuator to an extent where the actuator buttons are substantially flush with the outer surfaces of the elongated main body, although in some embodiment of actuators the actuator buttons are allowed to protrude radially by 1-3 mm. Figs. 13-15 illustrate an embodiment of the invention in which the actuator 4" is formed in one single component together with a membrane 72 which intersects the stems 68", 69" on each of the wings 73, 74. The wings 73, 74 extend in opposite directions from the interface 75. The interface 75 is joined with the membrane and with the body 76 of the pencil. Each of the wings 73, 74 forms one of the first and second actuator buttons (20", 22") .

The wings 73, 74 are joined to the interface via transition portions 77, 78 in which the bending stiffness in a direction towards the body is lower than the bending stiffness of the remaining portion of the wing. This is facilitated by a reduced wall thickness of the material at the transition portions as compared to the thickness of the wings 73, 74.

Claims

1. An electrosurgical pencil adapted to be connected to a generator capable of supplying electrosurgical cutting energy for cutting tissue and electrosurgical coagulation energy for coagulation of tissue during surgery, the pencil comprising an elongated body, an exposed electrode (3) located at a distal end of the elongated body, a switch means (5) for switching between supply of the electrosurgical cutting energy and the electrosurgical coagulation energy to the electrode (3), the switch means (5) comprising :

- at least two first electrical contacts (42;43) having at least one first main body part (47;48) configured as at least one first conductive sheet component (47;48), - at least one second electrical contact (44) having at least one second main body part (50) configured as at least one second conductive sheet component (50), wherein the first electrical contacts (42;43) and the at least one second electrical contact (44) are provided superjacent and spaced apart,

- an actuator (4;4';4") comprising a button means (20,20',20";22,22',22") including a first actuator button (20;20';20") above one of the first electrical contacts (42,

43) and a second actuator button (22;22',22") above the other one of the electrical contacts (42,43) such that a selected one of the first electrical contacts (42;43) can be pressed against the second electrical contact in response to a force applied to a respective one of the first and second actuator buttons (20,20',20";22,22',22"), wherein the first and second actuator buttons (20,20',20";22,22',22") are formed in a single piece of an elastically deformable material allowing movement of one of the actuator buttons independently from the other actuator button.

2. A pencil according to claim 1, characterised in that the single piece of an elastically deformable material forms an interface and two wings (73,74) extending in opposite directions from the interface (75), each wing forming one of the first and second actuator buttons (20,20',20";22,22',22"), and the interface being joined to the elongated body, wherein each wing is joined to the interface via a transition portion (77,78) in which the bending stiffness against bending in a direction towards the elongated body is lower than the bending stiffness of the remaining portion of the wing.

3. A pencil according to claim 2, comprising an oblong stem (68, 69;

68',69';68",69") extending from each wing towards one of the first electrical contacts (42, 43).

4. A pencil according to claim 3, comprising a membrane (72, 79) acting on each stem (68, 69; 68',69';68",69") and providing a home position towards which the stem and the corresponding wing is pressed by the membrane (72, 79).

5. A pencil according to claim 4, where the membrane (72, 79) is formed in one piece with the first and second actuator buttons (20, 20',20";22,22',22").

6. A pencil according to any of claims 4-5, where the stems (68, 69; 68',69';68", 69") are formed in one piece with the membrane (72, 79).

7. A pencil according to any of claims 2-6, where at least one of the interface and membrane (72, 79) is formed in one piece with at least a portion of the body.

8. A pencil according to any of claims 4-7, where the membrane forms a liquid tight seal into a first compartment 59a.

9. A pencil according to any of claims 4-8, where at least one of the interface, the membrane and the wings is formed in a material which is more elastically deformable than the material by which the body is formed.

10. An electrosurgical instrument (1) according to any of the preceding claims, characterised in that an insulating insert (45) is provided between the first electrical contacts (42;43) and the at least one second electrical contact (44) except on at least one area (49a,49b) left free of insulating insert (44) for allowing the first electrical contact (42;43) and the at least one second electrical contact (44) to get in contact with each other.

11. An electrosurgical instrument (1) according to any of the preceding claims, characterised in that the first electrical contacts (42;43) are provided in substantially the same first plane, the first plane being superjacent a second plane in which the at least one second electrical contact (44) is located.

12. An electrosurgical instrument (1) according to claim 11, characterised in that the first electrical contacts (42;43) are provided without physical contact with each other.

13. An electrosurgical instrument (1) according to any of the preceding claims, characterised in that the actuator (4;4';4") is configured to apply a force that moves at least a part of one of the first electrical contacts (42;43) in the direction towards the at least one second electrical contact (44) to close said superjacent first (42;43) and second (44) electrical contacts.

14. An electrosurgical instrument (1) according to any of the preceding claims, characterised in that the first main part of one of the first electrical contacts (42, 43) has a raised or projecting contact part (57; 58) facing the actuator (4;4';4"), which raised or projecting contact part (57,58) is designed to be displaced by means of the actuator (4;4';4") in the direction towards the at least one second electrical contact (44) to close said superjacent electrical contacts (42,43;44).

15. An electrosurgical instrument (1) according to any of the preceding claims, characterised in that the electrosurgical instrument (1) comprises

-a first electric wire (12a) that is connected to a first one of the first conductive sheet components (47) and adapted to supply the cutting energy from the generator,

-a second wire (12b) that is connected to a second one of the first conductive sheet components (48) and adapted to supply the coagulation energy from the generator, and -a third electrical wire (12c) that is connected to the second conductive sheet component

(50) and through which cutting or coagulation energy is applied to the exposed electrode (3) when a respective of the first conductive sheet components (47;48) is actuated by operating the actuator (4;4';4").