This invention relates to a surgical tool, in particular a tool that can serve various different functions in a neurosurgical operation.

In a typical operation a surgeon opens access to the body using a cutting device such as a scalpel. A microscope is then positioned over the body to provide magnification and the surgeon performs the operation using various different tools. Typical tools in neurosurgery include micro-scissors, a spatula, a suction device, and a bipolar tool that includes electrodes for cauterizing a wound. A surgeon generally switches between these tools many times over the course of an operation and a nurse will pass the surgeon the tool that is required. Each time that the surgeon changes tool there is likely to be a break in concentration. In addition, the surgeon will often need to break eye contact from the microscope to ensure that the new tool is received correctly. Changing tools in this way can increase surgery time and decrease the focus of a surgeon.

A number of devices have been considered that attempt to combine one or more of the functions provided by different surgical tools. In all of the devices considered by the inventors the results have been somewhat undesirable. In one example, the document US 5,352,222 describes surgical scissors that can also function as bipolar electrodes. A disadvantage in this tool is that the surgical scissors are inextricably linked to the bipolar electrodes. Therefore, it may be difficult to use the bipolar electrodes to cauterize a wound without cutting tissue accidentally.

Another example of a surgical scissors instrument is provided in US 5,908,420. In this arrangement scissor blades are provided on jaws of an instrument. The scissors blades are recessed from conductive jaws, between which a RF current can be applied. The jaws are operated using a pair of finger holes located on the other side of a pivot point. It has been found that this arrangement forces a surgeon to take a peculiar hand position that is not compatible with the accuracy and finesse required in cutting tissues during micro-surgery. The reach of the scissor blades is also limited by the position the conductive jaws. An object of the present invention is to provide a multi-function surgical tool that can alleviate some of the problems outlined above.

According to the present invention there is provided a surgical tool comprising: a pair of arms having a proximal end for being held by a user and a distal end for operating on a patient; a pair of electrodes, wherein each electrode in the pair is positioned on a respective arm, and wherein a current can be passed between the electrodes to seal a wound; and surgical scissors, movable with respect to the pair of arms between a retracted position in which the surgical scissors are stored and an extended position in which the surgical scissors are usable for cutting tissue.

In this way a single tool can provide the separate functions of cutting and cauterizing during surgery. This is advantageous because it means that a surgeon can perform these actions without changing tools in his hands and without diverting his gaze or attention. The electrodes may be used to cauterize a wound when the surgical scissors are in the retracted position. The surgical scissors may be used for cutting when they are in the extended position.

In the extended position the scissors are preferably located beyond the distal end of the arms. This allows the scissors to reach tissue without being impeded by the arms. In addition, it allows good visibility for the surgeon to see the scissors as they extend beyond the ends of the arms. With the surgical scissors in the retracted position the electrodes are preferably at the most distal end of the tool. Preferably the electrodes are isolated from a source of electricity when the surgical scissors are in the extended position. In this way the cutting and cauterizing functions may be provided independently, and electrodes cannot be used to cauterize a wound when the scissors are in their extended position. A switch may be activated when the scissors move from the retracted position to the extended position in order to isolate the electrodes. Alternatively, or in addition, an electrical insulator such as ceramic may be provided between the surgical scissors and the electrodes.

Each arm is preferably arranged to act on a respective blade in the surgical scissors so that the scissors can be closed when the arms are moved together. Thus, it may be possible to cut tissue with the scissors by simply squeezing the arms together, like a pair of tweezers. It has been found that this is a particularly convenient way to perform surgery as it enables the surgeon to have fine control, without contorting his hands into an unnatural position.

Preferably the surgical scissors are biased apart when they are in the extended position. Thus, the user can operate the arms to close the scissors and perform a cut. Releasing the arms may therefore allow the scissors to return to an open configuration.

At least one of the arms preferably comprises a guide for closing the blades of the surgical scissors together when they are moved from the extended position towards the retracted position. This allows the scissors to close together as they are retracted so that the scissors can be stored in a more compact configuration.

Conversely, the guide may be arranged to open the blades of the scissors when they are moved from the retracted position towards the extended position.

Preferably the surgical scissors are provided in a closed configuration in the retracted position. This is advantageous because it means that the surgical scissors can be provided in a compact configuration when they are stored so that they do not interfere with the operation of the electrodes.

According to the present invention there is provided a surgical tool comprising: a cutting edge; a pair of electrodes between which a current can be passed to seal a wound; and an electrical insulator arranged between the pair of electrodes and the cutting edge.

In this way a single tool can provide the separate functions of cutting and cauterizing during surgery. This is advantageous because it means that a surgeon can perform these actions without changing tools and without diverting his gaze or attention. By insulating the cutting edge from the pair of electrodes it is possible to perform only a cutting function or only a cauterizing function, as appropriate. The tool may also be used as a spatula in order to move tissue during the operation. The cutting edge and the pair of electrodes are preferably made of a metal such as titanium. The insulator may be a plastic or ceramic material to prevent electrical current flowing in the cutting edge. Two surgical tools may be provided, one for each of the surgeon's hands. The tools may therefore act as an extension of the surgeon's fingers for fine manipulation of tissues. In some embodiments a different tool may be used in each of the surgeon's hands; for example, the non-dominant hand of the surgeon may be used for holding a suction device.

A pair of opposing cutting edges can be provided as surgical scissors. The scissors can be used to cut tissue during surgical operations and the pair of electrodes can be used separately to cauterize a wound and stop bleeding. Preferably the opposing cutting edges are offset from one another. In this way a shear cutting force may be applied to provide a clean cut for tissue in between the scissor blades.

Preferably the pair of electrodes are provided at the most distal end of the tool from the perspective of an operator. The cutting edge may be provided closer to the operator than the pair of electrodes. The cutting edge may therefore be recessed from the distal end of the device relative to the electrodes.

Preferably the tool comprises a pair of arms and each electrode in the pair is positioned on a respective arm. The electrodes may be arranged to face one another on surfaces of the respective arms. A wound can be positioned between inward-facing surfaces of the arms so that it can be cauterized. The arms may be biased apart. The surgeon must therefore take an active step to close the arms and cut or cauterize tissue.

The arms may also be closed so that the surgeon can hold tissue and move it around. The surgeon may therefore be able to use the tool as a spatula without changing hands or diverting attention from the operation. Preferably the electrical current is switched off when the tool is being used as a spatula so that tissue is not damaged while it is being manipulated. In one arrangement a latch mechanism may be provided for locking the arms in the closed position; this may be useful in one example for operating on aneurysms. In one arrangement a curette may be formed by the closed arms for scraping or debriding tissue during an operation.

A guide may be provided between the respective arms for guiding the distal ends of the respective arms together. The guide may make the tool easier to operate for a surgeon. In particular the guide may ensure that the distal ends of the arms come together so that they can be used effectively as a spatula, scissors or as a bipolar tool. Preferably a suction device is provided to drain fluid from the area of surgery. In this way the surgical tool can perform many of the functions that are otherwise performed by different tools during an operation. This can provide safer and better surgical results because the surgeon does not need to divert attention from the surgery when changing between tool functions.

The suction device may comprise a tube that terminates towards the distal end of the tool. The tube may be arranged on an outside surface of the tool or it may be arranged internally in the tool. By terminating the tool at a distal end of the tool the tube can be positioned in order to drain away excess fluid such as blood. A control may be provided for the suction, and the control may be thumb-activated. In this way the surgeon can turn suction on or off without diverting attention. In a preferred embodiment the control may be used to increase or decrease the strength of suction. The control may comprise an aperture that can be fully or partially occluded by the surgeon to increase the strength of suction at the distal end of the tool.

The tool may comprise a proximal section which can be held by an operator and a distal section including the cutting edge and the pair of electrodes. Preferably the distal section is angled relative to the proximal section to provide a direct line of sight to the cutting edge and the pair of electrodes for the operator. This can provide better visibility for a surgeon during an operation, especially when the surgery is being performed with a microscope. The angled distal section allows a surgeon a direct view "down the barrel" of the tool to the distal end where the operating components are preferably situated. This means that the arms can be closed together without adversely interfering with the surgeon's visibility. The tool may comprise an intermediate section that is angled relative to the proximal section and the distal section. It has been found that this provides an ergonomic construction that allows easy operation of the tool by the surgeon. The guide may be connected between the arms in the intermediate section.

A foot-activated switch may be provided for activating a current in the pair of electrodes. Alternatively the switch could be mouth-activated. The electrodes can therefore be activated selectively when the surgeon wishes to cauterize a wound and stop bleeding. The surgeon can also activate the electrodes without diverting attention from the surgery.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a surgical tool in an embodiment of the invention; Figure 2 is a top view of the surgical tool shown in Figure 1 ; Figure 3 is a side view of the surgical tool shown in Figure 1 ;

Figure 4 is a top view of one end of the surgical tool shown in Figure 1 ; Figure 5 is a detailed end view of the surgical tool shown in Figure 1 ;

Figure 6 is a cross-sectional view of the surgical tool shown in Figure 1 ; Figure 7 is another cross-sectional view of the surgical tool shown in Figure 1 ; Figure 8 is another end view of the surgical tool shown in Figure 1 ;

Figure 9 is a perspective view of a surgical tool in another embodiment of the invention, in which surgical scissors are in a stored position; Figure 10 is another perspective view of the surgical tool shown in Figure 9, in which the surgical scissors are in an extended position;

Figure 1 1 is a side view of the surgical tool shown in Figure 9;

Figure 12 is a side view of the surgical tool shown in Figure 10;

Figures 13A-D are side views of the surgical tool shown in Figure 9, showing the movement of the surgical scissors from the extended position to the stored position;

Figure 14 is an exploded view of the surgical tool shown in Figure 9;

Figure 15 is a view of a headset that can be used in an embodiment of the invention; Figure 16 is a perspective view of a user holding a surgical tool in an embodiment of the invention;

Figure 17 is a perspective view of a control for use with a surgical tool in an embodiment of the invention;

Figure 18 is a perspective view of a user holding a surgical tool in an embodiment of the invention;

Figure 19 is another perspective view of a user holding a surgical tool in an embodiment of the invention; and

Figure 20 is a perspective view of the distal end of a surgical tool in an embodiment of the invention. An embodiment of a surgical tool 10 will now be described with reference to Figures 1 to 8. The surgical tool 10 comprises a pair of arms 12, 14 pivotally attached to one another at a proximal end of the tool from the perspective of an operator. The arms 12, 14 are biased apart and the force that is required to close the arms 12, 14 is determined by their material and tension. A latch (not shown) may be arranged to lock the arms in the closed position.

Each arm 12, 14 comprises a proximal section 18, an intermediate section 20 and a distal section 22. The proximal section 18 is designed as a handle for a surgeon and includes ridges 19 for improved grip. The surgeon may also close the arms 12, 14 together by resting his fingers on the intermediate section 20. The intermediate section 20 is angled downwards, in use, relative to the proximal section 18. The distal section 22 is angled upwards, in use, relative to the intermediate section 20. This configuration allows the surgeon a clear view "down the barrel" of the device to the extreme distal end of the tool where the tool is likely to come into contact with a patient.

The tool comprises a pair of electrodes 28, 30 facing one another on respective arms 12, 14 at the distal end of the tool. The electrodes 28, 30 are connected to electrical wires that are fed internally or externally through the arms 12, 14. A foot-activated switch (not shown) is provided so that the surgeon can activate the electrodes and pass a current between them. When the foot switch is activated the current would flow through tissue that has been placed between the electrodes 28, 30 and the current would cauterize a wound and prevent bleeding. Electrical insulators 32, 34 are provided at the distal end of the tool between the scissor blades 24, 26 and the electrodes 28, 30. The electrical insulators 32, 34 ensure that the bipolar and cutting functions can be provided independently. The tool comprises a pair of scissor blades 24, 26 extending towards each other at the distal end of the tool. The scissor blades 24, 26 are arranged substantially parallel to the distal section 22 of the tool and they are offset from one another. By offsetting the blades 24, 26 a shear cutting force can be applied to tissue that is cut by the surgeon. The scissor blades 24, 26 are slightly recessed from the extreme distal end of the tool to provide space for the electrodes 28, 30.

A cylinder 40 is provided at the proximal end of the tool 10 for connecting a suction tube 36 to a vacuum generator and for connecting electrical wiring 42, 44 to a power source. The suction tube 36 extends in a bore through the cylinder and one or both of the arms 12. The electrical wiring 42, 44 extends through respective arms 12, 14 to connect the electrodes 28, 30 to a power source.

The suction tube 36 terminates at the distal end of the tool and suction can be provided to drain fluid such as blood from the operating area. A thumb-operated control 38 is provided in the proximal section 18 of the tool for controlling suction. The control 38 is a crescent shaped opening that is connected to the suction tube 36. The crescent shaped opening can be occluded by the surgeon's thumb to increase or decrease suction as required by the circumstances. The suction tube 36 may also be used to irrigate the operating area.

In use a surgeon can hold the tool 10 and cut tissue using the scissor blades 24, 26. A wound can be cauterized using the electrodes 28, 30 in the bipolar device. In addition, excess fluid can be drained using the suction tube 36. Furthermore, tissue can be gripped between the electrodes 28, 30 when no current is flowing so that the tissue can be manipulated. These four surgical functions can be provided without the surgeon needing to switch tools or divert attention from the operation.

In an alternative arrangement, shown in Figure 20, the ends of the arms 12, 14 may be shaped with complementary halves of a concave recess. Thus, when the arms 12, 14 are brought together a concave recess 500 is formed, which can be used as a curette during surgery. The curette can be used gently during surgery to scratch and remove tissue. A variety of alternative techniques may be provided for controlling suction, irrigation and the electrodes 28, 30. In one example, shown in Figure 15, a headset 188 is provided having a teeth activated switch 190 with which a user may activate the electrodes 28, 30. The headset 188 is connected to the tool 10 using a wireless protocol, such as Bluetooth®. The headset 188 also comprises a straw 192 with which the user can control suction or irrigation from tube 36. By exhaling the user can start irrigation/suction and by inhaling the user can stop the suction/irrigation. Alternatively exhaling may be used to control irrigation and inhaling may be used to control suction. The force with which the user inhales/exhales into the straw 192 may also be used to control the level of suction/irrigation. In another example, shown in Figure 16, piezoelectric sensors 200 may be provided in one of the arms 12, 14 of the tool. The force with which the user holds the piezoelectric sensor 200 may be used to control the amount of suction or irrigation. Figure 17 shows a switch 202 comprising zones 204, 206, 208 which can be selected to enable the user to toggle between irrigation, suction and electrode control. By selecting an appropriate zone in the switch 202 the user may be able to user the piezoelectric sensor 200 to control irrigation, suction or the electrodes 28, 30 in the tool 10.

Figures 18 and 19 show alternative embodiments for the switch shown in Figure 17. In Figure 18 a switch 300 is provided in a strap that is wrapped around the user's ring finger. The user can activate the switch 300 by tapping their ring finger against the base of their thumb. In Figure 19 a switch 400 is provided on the base of the user's thumb. The user can activate the switch 400 by selecting it with one their fingers (in this example, their ring finger). In the examples of Figures 18 and 19 the switches 300, 400 can be used to cycle through control of the different functions of the tool.

Figures 9-12 show perspective and side views of a tool 1 10 in another embodiment of the invention. Figure 14 shows an exploded view. The tool 1 10 comprises a pair of electrodes 128, 130 facing one another on respective arms 1 12, 1 14 at the distal end of the tool. In addition, the tool 1 10 comprises a pair of scissor blades 124, 126. The scissor blades 124, 126 are movable between a stored position, shown in Figures 9 and 1 1 and an extended position, shown in Figures 10 and 12.

The tool 1 10 also includes an actuation bar 125 connected to the first scissor blade 126 with a pivot link 127. The actuation bar 125 is arranged to rest on a ledge 131 . The actuation bar is held in place between a lip 133 and a cover 129 which is assembled outside the first scissor blade 126. The first scissor blade 126 is connected to the pivot link 127 and the second scissor blade 124 with a pin 1 19. The scissor blades 124, 126 therefore pivot, in use, about the pin 1 19.

The actuation bar 125 is arranged, in use, to drive the scissor blades 124, 126 from their stored position to the extended position. A slide (not shown) is provided at the proximal end of the arm 1 14, and movement of the slide can drive the actuation bar 125 towards the distal end of the tool 1 10. In their extended position the ends of the scissor blades 124, 126 represent the most distal end of the tool, as they extend beyond the electrodes 128, 130. In their stored position the ends of the scissor blades 124, 126 are arranged along the arm 1 14 in a position that is proximal with respect to the electrode 130.

The tool 1 10 also includes a spring 123, which is arranged to bias the scissor blades 124, 126 apart when they are in their extended position. The spring is arranged to flex about a pivot point 135 where it is attached to the arm 1 14. The operation of the spring becomes apparent from Figures 13A-D which show side views of the surgical tool 1 10 in different configurations. In Figure 13A the scissor blades 124, 126 are fully extended and in Figure 13D the scissor blades are fully retracted. The second scissor blade 124 comprises a plate 1 17 at its distal end that rests against the ramp 1 15 when the scissors are in their stored position. A lip 121 is provided at the top of the ramp 1 15 to limit the extent of movement of the plate 1 17 in the stored position. As the scissor blades 124, 126 are pushed to the extended position by the actuation bar 125 the plate 1 17 slides off the ramp 1 15 and onto a flat section 135 of the arm 1 14. This causes the scissor blades 124, 126 to open. In the extended position the plate 1 17 fits in a gap between the spring 123 and the flat section 135 of the arm. This biases the scissor blades 124, 126 in an open configuration when they are in the extended position, as shown in Figure 13A.

In order to cut tissue the scissor blades 124, 126 must be closed together. This is achieved when the user pinches the arms 1 12, 1 14 and forces them together. The arms 1 12, 1 14 come into contact with the respective scissor blades 124, 126 and cause them to close together in order to cut tissue. As the scissor blades 124, 126 come together the plate 1 17 pivots between the spring 123 and the flat section 135 of the arm, causing the spring 123 to flex. The flexing spring 123 creates a biasing force against closure of the scissor blades 124, 126, and this causes the blades to open in the absence of a pinching force from the user.

The electrodes 128, 130 are arranged to be isolated from their electrical source when the scissors 124, 126 are in their extended position. This is provided by activating a switch (not shown) when the actuation bar 125 drives the scissor blades 124, 126 into their extended position. This action allows the surgical scissors to be used without any electrical current passing between them (which enables separation of the cutting and cauterizing functions of the tool). Alternatively, or in addition, the scissor blades 124, 126 are provided on a ceramic mounting so that they can be electrically isolated from the electrodes 128, 130. The second scissor blade 126 may even be made entirely from ceramic to ensure that no electrical current can pass between the blades 124, 126.