the fluid capture chamber 240 defined by sleeve 170 and distal tip 232 can be designed to have a selected volume exposed electrode surface area length and geometry to optimize the application of expelling forces to resected tissue strips 225 in one embodiment the diameter of the chamber is 3 175 mm and the length is 5 0 mm which taking into account the projecting element 230 provided a captured fluid volume of approximately 0 040 ml in other variations the captured fluid volume can range from 0 004 ml to 0 080 ml in one example a chamber 240 with a captured liquid volume of 0 040 ml together with 100 conversion efficiency in and instantaneous vaporization would require 103 joules to heat the liquid from room temperature to water vapor in operation since a joule is a w s and the system reciprocate at 3 hz the power required would be on the order of 311 w for full instantaneous conversion to water vapor a corresponding theoretical expansion of 1700 u00d7 would occur in the phase transition which would results in up to 25 000 psi instantaneously 14 7 psi u00d7 1700 although due to losses in efficiency and non instantaneous expansion the actual pressures would be much less in any event the pressures are substantial and can apply significant expelling forces.