System and method for endometrial ablation
View Patent ↗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 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.
1. A medical method for ablating tissue, comprising:
creating a negative pressure in a neutral gas in a fluid-tight chamber of a dielectric positioned adjacent to targeted tissue;
applying RF energy to ignite and maintain a plasma in the negative pressure neutral gas;
adjusting the negative pressure toward an ambient pressure while maintaining the plasma, wherein the dielectric delivers energy to the targeted tissue.
2. The method of claim 1 wherein creating the negative pressure is initiated at between −0.25 psig and −10 psig.
3. The method of claim 1 wherein creating the negative pressure is initiated at between −0.5 psig and −5 psig.
4. The method of claim 1 further comprising terminating the negative pressure after initiating RF application.
5. The method of claim 4 wherein terminating the negative pressure occurs between 0.1 and 10 seconds after initiating RF application.
6. The method of claim 1 wherein the applying step applies at least 150 volts.
7. The method of claim 6 wherein applying at least 150 volts occurs for less than 10 seconds, less than 5 seconds or less than 2 seconds.
8. The method of claim 1 wherein the applying step includes a voltage spike of at least 150 volts to initiate plasma followed by a plasma-maintaining voltage to maintain the plasma over a treatment interval.
9. The method of claim 1 wherein the adjusting step includes adjusting the pressure to a positive pressure.
10. The method of claim 9 wherein the positive pressure is at least +0.1 psig.
11. The method of claim 9 wherein the positive pressure is in the range of +0.5 psig to 10 psig.
12. The method of claim 1 wherein the creating step includes an initial stage that creates a negative pressure that is below −5 psig in the fluid-tight chamber of the dielectric positioned outside a patient's body to facilitate trans-cervical introduction of the dielectric.