Methods, systems and devices for evaluating the integrity of a uterine cavity. A method comprises introducing transcervically a probe into a patient's uterine cavity, providing a flow of a fluid (e.g., CO.sub.2) through the probe into the uterine cavity and monitoring the rate of the flow to characterize the uterine cavity as perforated or non-perforated based on a change in the flow rate.

A catheter tip electrode has a tissue contacting surface which electrically conducts RF energy to the tissue and is more thermally conductive than adjacent non-electrically conductive coating or cover which prevents RF conduction to the tissue contacting that surface. The tip electrode has a shell with a nonablating hollow proximal neck portion and a distal ablating portion defining a fluid chamber, and a plug-like support member which is configured with a fluid channel on its outer surface so a fluid passage is provided between the member and the neck portion for convective or direct cooling of the nonablating neck portion and nonconductive tubing covering it.

A tissue treatment selection device that has at least one treatment delivery member, a delivery setting circuit that is coupled to the treatment delivery member that is adapted to be deployed into tissue to deliver therapeutic energy to a target tissue zone, and the processing circuit is operable to set treatment parameters in the delivery setting circuit. The processing circuit is operable to transmit a test signal through the deployed treatment delivery member and to determine deployment status. The treatment selection device has a processing circuit adapted to send a message to a display device that indicates that the deployed treatment delivery member has been determined to be compensable and contains a suggested change in the treatment parameters. Also presented herein is a method of treating a tissue of a patient using the treatment delivery device.

Systems and methods for endometrial ablation. The systems include a handle and elongated introducer sleeve extending to an expandable working end having a fluid-tight interior chamber. A thin dielectric wall surrounds at least a portion of the interior chamber and has an external surface for contacting endometrial tissue. The thin dielectric wall surrounds a collapsible-expandable frame and receives an electrically non-conductive gas. First and second polarity electrodes are exposed to the interior and exterior of the chamber, respectively. A radiofrequency power source operatively connects to the electrode arrangement to apply a radiofrequency voltage across the first and second electrodes, wherein the voltage is sufficient to initiate ionization of the neutral gas into a conductive plasma within the interior chamber, and to capacitively couple the current in the plasma across the thin dielectric wall to ablate endometrial tissue engaged by the external surface of the dielectric structure.

A system for treating uterine tissue having a seal assembly configured for positioning in a patient's cervical canal and uterine cavity; an expandable distal balloon portion; an expandable elongate medial balloon portion configured for movement between a first transversely expanded shape for engaging a cervical canal and a second transversely non-expanded shape for trans-cervical insertion; and a fluid source in communication with distal balloon portion and medial balloon portion for expansion of said balloon portions.

Tumors can be treated with an alternating electric field. The size of cells in the tumor is determined prior to the start of treatment by, for example, biopsy or by inverse electric impedance tomography. A treatment frequency is chosen based on the determined cell size. The cell size can be determined during the course of treatment and the treatment frequency is adjusted to reflect changes in the cell size. A suitable apparatus for this purpose includes a device for measuring the tumor impedance, an AC signal generator with a controllable output frequency, a processor for estimating the size of tumor cells and setting the frequency of the AC signal generator based thereon, and at least one pair of electrodes operatively connected to the AC signal generator such that an alternating electric field is applied to the tumor.

Methods, systems and devices for evaluating the integrity of a uterine cavity. A method comprises introducing transcervically a probe into a patient's uterine cavity, providing a flow of a fluid (e.g., CO.sub.2) through the probe into the uterine cavity and monitoring the rate of the flow to characterize the uterine cavity as perforated or non-perforated based on a change in the flow rate.

An energy applicator is introduced to a uterine cavity through an endocervical canal while a gas is being introduced into the uterine cavity. The endocervical canal is sealed, and visually observing a flow rate of the gas allows a user to determine if the seal is effective. Inflation of the cavity facilitates opening of a working end of the applicator within the cavity.

Methods, systems and devices for endometrial ablation. In accordance with a method, a working end of an RF ablation device is positioned in a patient uterus to contact endometrial tissue, the working end comprising a dielectric wall capable of non-expanded and expanded shapes. An indicator mechanism is operatively coupled to the wall and configured to indicate non-expanded and expanded shapes of the wall.

A system for treating uterine tissue having a seal assembly configured for positioning in a patient's cervical canal and uterine cavity; an expandable distal balloon portion; an expandable elongate medial balloon portion configured for movement between a first transversely expanded shape for engaging a cervical canal and a second transversely non-expanded shape for trans-cervical insertion; and a fluid source in communication with distal balloon portion and medial balloon portion for expansion of said balloon portions.