Electrosurgical forceps instrument
An electrosurgical forceps instrument in which an energy conveying structure for efficiently transferring electromagnetic energy (e.g. microwave energy and/or radiofrequency energy) from a coaxial cable to electrodes on the forceps jaws is incorporated into a compact jaw opening structure. The jaw opening structure may be dimensioned to be suitable for insertion down the instrument channel of a endoscope or other scoping device. Alternatively, the device may be configured as a laparoscopic device or be used in open procedures. The instrument may be used as a tool to perform new minimally invasive surgical techniques such as Natural Orifice Transluminal Endosurgery (NOTES) or the like.
1. An electrosurgical forceps comprising:
a coaxial cable for conveying microwave energy;
a pair of jaws mountable at a distal end of the coaxial cable, the pair of jaws being movable relative to each other to open and close a gap between opposing inner surfaces thereof,
wherein the pair of jaws comprises a first jaw having:
an outer jaw element operably engagable with an actuating element for causing relative movement between the pair of jaws,
an inner jaw element attached to the outer jaw element to form the inner surface of the first jaw, the inner jaw element comprising an applicator pad having a first electrode and a second electrode formed thereon, and
an energy transfer element comprising a flexible dielectric substrate which extends from a distal end of the coaxial cable to a proximal portion of the applicator pad, the flexible dielectric substrate having a pair of conductive tracks formed thereon for conveying microwave energy from the coaxial cable to the first electrode and second electrode, wherein the flexible dielectric substrate is flexible to permit flexing of the pair of conductive tracks.
2. An electrosurgical forceps according to claim 1 , wherein the pair of jaws comprises a second jaw disposed opposite the first jaw, the second jaw having:
an outer jaw element operably engagable with an actuating element for causing relative movement between the pair of jaws,
an inner jaw element attached to the outer jaw element to form the inner surface of the first jaw, the inner jaw element comprising an applicator pad having a first electrode and a second electrode formed thereon, and
an energy transfer element comprising a flexible dielectric substrate having a pair of conductive tracks formed thereon for conveying microwave energy from the coaxial cable to the first electrode and second electrode.
3. An electrosurgical forceps according to claim 2 , wherein the first electrode and second electrode on the first jaw oppose the first electrode and second electrode on the second jaw across the gap between the pair of jaws, and wherein the electrodes that oppose each other across the gap have opposite electrical polarities.
4. An electrosurgical forceps according to claim 3 , wherein the coaxial cable is arranged to convey radiofrequency (RF) energy to set up an electric field across the gap that is suitable for cutting biological tissue.
5. An electrosurgical forceps according to claim 1 , wherein the pair of conductive tracks are formed on opposite sides of the flexible dielectric substrate.
6. An electrosurgical forceps according to claim 1 , wherein the pair of conductive tracks comprise a first conductive track electrically connected to an inner conductor of the coaxial cable, and a second conductive track electrically connected to an outer conductor of the coaxial cable.
7. An electrosurgical forceps according to claim 6 , wherein the first conductive track is electrically connected to the first electrode and the second conductive track is electrically connected to the second electrode.
8. An electrosurgical forceps according to claim 1 , wherein the applicator pad has a hole formed therethrough, and wherein one of the first electrode and second electrode is connected to one of the pair of conductive tracks via the hole.
9. An electrosurgical forceps according to claim 1 , wherein the outer jaw element is preformed to bias the pair of jaws into an open configuration.
10. An electrosurgical forceps according to claim 1 , wherein the outer jaw element comprises a living hinge.
11. An electrosurgical forceps according to claim 1 , wherein the flexible dielectric substrate is a ribbon having a width greater than a width of the pair of conductive tracks.
12. An electrosurgical forceps according to claim 1 , wherein the applicator pad is a piece of ceramic, PEEK or PTFE.
13. An electrosurgical forceps according to claim 1 , wherein the applicator pad is an exposed distal portion of the flexible substrate.
14. An electrosurgical forceps according to claim 1 , wherein the first electrode and second electrode comprise parallel elongate strips of conductive material on the inner surface of the jaw.
15. An electrosurgical forceps according to claim 14 , wherein the parallel elongate strips of conductive material are straight, meandering, ‘L’ shape, or triangular.
16. An electrosurgical forceps according to claim 1 , wherein the energy transfer element is dimensioned to match an impedance of the coaxial cable with an impedance of the first electrode and second electrode.
17. An electrosurgical forceps according to claim 1 , wherein the actuating element is a sleeve slidably mounted on the coaxial cable.
18. An electrosurgical forceps according to claim 17 , wherein the sleeve comprises a flexible proximal portion and a rigid distal portion.
19. An electrosurgical forceps according to claim 18 , wherein the rigid distal portion has a length equal to or less than 10 mm.
20. An electrosurgical forceps according to claim 18 , wherein the sleeve comprising an encapsulated braid, wherein a density of the braid within the encapsulation is greater in the rigid distal portion than in the flexible proximal portion.
21. An electrosurgical forceps according to claim 1 , wherein the pair of jaws are dimensioned to fit within an instrument channel of a surgical scoping device.
22. An electrosurgical apparatus comprising:
an electrosurgical generator for supplying microwave energy;
a surgical scoping device having an instrument cord for insertion into a patient's body, the instrument cord having an instrument channel extending therethrough;
an electrosurgical forceps according to claim 1 mounted in the instrument channel; and
a handle for actuating the forceps,
wherein the coaxial cable is connected at its proximal end to receive microwave energy from the electrosurgical generator, and
wherein the actuating element is operably connected to the handle.
23. An electrosurgical apparatus according to claim 22 , wherein the actuating element is a sleeve that extends around and is axially slidably relative to the coaxial cable.
24. An electrosurgical apparatus according to claim 23 , wherein the handle comprises an actuation mechanism for controlling axial movement of the sleeve, the actuation mechanism comprising:
a body fixed in the handle;
a carriage slidable relative to the body, and
a lever pivotably mounted on the body and operably engaged with the carriage, whereby rotation of the lever caused sliding motion of the carriage,
wherein the sleeve is attached to the carriage.
25. An electrosurgical apparatus according to claim 24 , wherein the actuation mechanism includes a biasing element arranged to urge the carriage in a proximal direction.