| 摘要 |
An electrosurgical instrument 1 for delivering microwave energy into a biological tissue 21 at a predetermined operating frequency. The instrument comprises a first coaxial transmission line 3 and a second coaxial transmission-line 5. Distal end of the first transmission-line is connected the proximal end of the second transmission-line. The second transmission-line has a length and a characteristic impedance configured to match the impedance of the first transmission-line to a load impedance at the distal end of the second transmission-line when it is in contact with the tissue at the operating frequency. The second inner and outer conductors may be exposed at the proximal end face of the second coaxial transmission-line for tissue contact. There may be a third coaxial transmission-line 33,fig.11, with its distal end connected to the proximal end of the second transmission-line and its proximal end for contact with the tissue, where the third transmission-lines characteristic impedance may be the same as that of the second transmission-line and where the third transmission-line length may be such that it cancels out a reactive part of the tissues characteristic impedance, where the instrument may also have an open or short circuited stub across the third transmission-line. Possible use for coagulation. |
