Multi frequency and multi polarity complex impedance measurements to assess ablation lesions

摘要

A method of assessing a tissue ablation treatment, including positioning a medical device adjacent a target tissue; measuring a first impedance magnitude a first frequency with the medical device; measuring a first impedance phase at a second frequency with the medical device; ablating at least a portion of the target tissue with the medical device; measuring at second impedance magnitude at a third frequency with the medical device; measuring a second impedance phase at a fourth frequency with the medical device; comparing at least one of (i) the first and second impedance magnitudes and (ii) the first and second impedance phases; and providing an indication of the efficacy of the ablation treatment based at least in part on the comparison.

主权项

1. A method of assessing an efficacy of a medical treatment, comprising:
positioning a medical device proximate a tissue site; delivering non-ablative radiofrequency energy to the tissue site in both unipolar mode and bipolar mode; obtaining baseline impedance characteristics at a first plurality of frequencies with the medical device in both the unipolar and bipolar modes; terminating the delivery of the non-ablative radiofrequency energy to the tissue site; delivering ablative radiofrequency energy to the tissue site at a first frequency in at least one of the unipolar and bipolar modes and obtaining in-treatment impedance characteristics at the first frequency in the at least one of the unipolar and bipolar modes; terminating the delivery of the ablative radiofrequency energy; then delivering the non-ablative radiofrequency energy to the tissue site in both the unipolar and bipolar modes; obtaining post-treatment impedance characteristics at a second plurality of frequencies with the medical device in both the unipolar and bipolar modes, the first frequency being different than at least one of the frequencies of the first and second plurality of frequencies; performing a comparison between the post-treatment impedance characteristics and the baseline impedance characteristics; and generating an indication of the efficacy of the medical treatment based at least in part on the comparison.