The method comprises inserting an interuterine sheath through a guide tube into the uterus of a patient, and then inserting the shaft of the resectoscope to a predetermined depth within the uterus. A medical procedure is performed with the resectoscope, such as scraping the interuterine walls. An irrigation liquid is charged into the uterus and then collected from the uterus, while being monitored in order to provide an indication of perforation of the interuterine wall. The method is completed by removing the resectoscope, interuterine sheath and guide tube from the patent.

An electrosurgical apparatus comprises a high frequency generator (1) with an associated power control system, a handpiece (2) with means for removably mounting an electrode (5) therein, and a connection cable (3) between an output (4) of the generator and the handpiece. The transfer characteristic of the system provides a substantially true ohmic transfer of loads on the electrode side of the connection cable (3) to the generator side thereof at or around a predetermined load on the electrode. In order to achieve a fully automatic and optimalized control af power supplied from a cutting electrode, whereby the control is instantly responding, to changes in the electrode load, the electrosurgical apparatus is characterized in that the power control system comprises a driver stage (7) followed by a reflectormeter (9) adapted and arranged to sense the generator output (4). A detector (10) supplies a detector signal which represents the reflected signal on the output (4), and the detector signal is communicated to the driver stage (7) for controlling the gain thereof.

A tuner system for a microwave power supply used in an ablation catheter system is disclosed. The tuner system includes a tuner arranged to facilitate matching the impedance of a power generator side portion of the catheter system with the impedance of a catheter side portion of the catheter system. A reflected power monitor is also provided for monitoring the amount of power that is reflected from the catheter during use. In a preferred aspect of the invention, the tuner is used in a power supply that includes a microwave power source and is used in conjunction with a catheter having a coaxial transmission line and a helical antenna. In a method aspect of the invention, a method for medical treatment using a microwave ablation catheter system is disclosed.

A transcutaneous uterine contraction inhibiting device comprises a first plurality electrode positioned on an anterior side of an abdomen of a patient, a second plurality electrode positioned on the anterior side, and an electric current generator establishing electric current flow between the first plurality electrode and the second plurality electrode. The first plurality electrode is positioned above an upper portion of the uterus and extends laterally across the uterus. The second plurality electrode is positioned on a mid to lower portion of the uterus and also extends laterally across it. Further, a feedback unit can be provided for generating a signal indicative of any uterine contractions. The electric current generator then establishes an electric current in response to the signal from the feedback unit.

An ablation catheter is disclosed that include a mechanism for altering the impedance of the antenna during use in a controlled manner to tune the catheter. The impedance tuning may be accomplished in a variety of manners including altering the electromechanical configuration of the antenna and moving a material relative to the antenna or vice versa in order to vary the effective impedance during use. In a preferred embodiment, the ablation catheter transmits energy in the microwave frequencies and uses a coaxial transmission line as its waveguide. The antenna is preferably helical in nature and is carried by the distal end of the transmission line.