| 摘要 |
A coaxial electrosurgical instrument has an elongate inner electrode insulated from and contained coaxially within a hollow tubular elongate outer electrode. Both electrodes have respective distal end portions which are uninsulated and contactable simultaneously to tissue to be operated on. A controlled, high-frequency, potential difference is provided between the electrodes under the user's control when the uninsulated distal end portions thereof are simultaneously contacted to tissue. A high frequency, high density, electrical current is thus caused to flow substantially only through that part of the contacted tissue which lies between the contacting portions of the inner and outer electrodes. Tissue is readily and cleanly cut between the inner and outer electrodes applying a continuous, undamped high frequency voltage difference. Cauterization and coagulation of the contacted tissue between the inner and outer electrodes may be performed by applying a periodically damped frequency electrical potential difference between the inner and outer electrodes. The outer electrode is preferably formed to have an inclined end surface, and the cooperating inner electrode is advantageously formed with a distal end part inclined to enable hooking of selected tissue to perform the surgical operations with improved visibility to the user.
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