Bipolar radio-frequency surgical instrument

DETAILED DESCRIPTION It is an object of the invention to provide a bipolar radio-frequency surgical instrument of the initially named kind which is suitable in particular for laparoscopic surgery, i.
e.
which is insertable through a trocar to the site of the operation without any problems, while at the same time allowing a perfect view of the coagulating process or cutting process for the operator even in the case of an approximately axial direction of the view.
To achieve this, a bipolar radio-frequency surgical instrument is provided with a rigid tube shaft and a working tip which preferably has substantially the same cross-section as the adjoining part of the tube shaft and is preferably centrally provided with at least one working electrode, such as a cutting electrode or a coagulating electrode which can be energized with a radio-frequency voltage, and a neutral electrode which preferably has a significantly larger surface.
The working tip is connected with the rigid tube shaft near the distal end of the instrument in a hinged or flexible manner in such a way that the working tip can be pivoted from a position which is axially aligned with the tube shaft to a position which forms an angle relative to the tube shaft.
Means is further provided to pivot and return the working tip.
Thus, in accordance with the invention the instrument can be used alternatively with the working tip which is axially aligned with the tube shaft or bent from the tube shaft.
During the insertion or extraction through a trocar, the working tip is aligned with the tube shaft in accordance with the invention, so that there are no laterally projecting parts at the distal end which inhibit the movement of the instrument within the trocar or in the body of the person being operated upon.
The working tip can then be pivoted in the region of the site of the operation so that it enters the viewing range of, for example, an operator viewing the operation through an endoscope.
It is known to form the distal end of endoscopes (DE 39 05 455 C2; EP 0 422 842 A2) or of catheters (EP 0 489 937 A1) in a manner which is controllably bent in order to reach regions within the body that could not be reached by a straight-lined instrument