Abstract: Instruments having a hood that defines and surrounds a flow chamber. The flow chamber can serve for suction of emissions that are produced due to influence of an electrode supplied with high frequency voltage on biological tissue. For elimination of tissue deposition and other clogging from the flow chamber the electrode is surrounded by a movable hood that can be transitioned for cleaning purposes out of its operating position into a cleaning position.

Abstract: An instrument according to the invention for medical or surgical treatment of a human or animal patient comprises at least one tool suitable for influencing a patient, e.g. an electrode, which is or are located in the field of view of an optical element. The optical element is arranged inside a channel in which a fluid flow can be maintained or can be caused in distal direction. The light passage window of optical element is offset relative to the distal opening of channel in proximal direction. A closure device is arranged between light passage window and opening of channel, which blocks passage of substances, particularly passage of liquid droplets and particles, from the opening to the light passage window as long as it is in closed position. If the closure device is open, it unblocks the fluid path and the light path between the light passage window to the opening. Preferably the closure device is controlled pneumatically by means of the liquid or gaseous fluid flowing inside channel.

Abstract: An instrument having a dosing unit connected to a handle or housing of instrument. The dosing unit may include a reusable actuator with a drive unit and a single-use cartridge. The Cartridge may have a cylinder and a piston, and may be filled by a user prior to the intervention or may be prefilled by the manufacturer. The dosing unit is brought into an open position offset from housing by, for example, operating a latch slider and pulling the dosing unit in a proximal direction. After insertion of the cartridge, the dosing unit may be moved toward housing and the latched slider will lock the dosing unit into a closed position.