Detection of ablation electrode contact with tissue

摘要

A method includes delivering a Radio Frequency (RF) signal having a time-varying power from an intra-body probe to tissue in a vicinity of the probe in order to ablate the tissue. A temperature is measured in the vicinity of the probe. A decision is made as to whether the probe is in contact with the tissue, by comparing the measured temperature to a temperature threshold that varies in time depending on the time-varying power of the RF signal.

主权项

1. A method, comprising:
delivering a Radio Frequency (RF) signal having a time-varying power from an intra-body probe to tissue in a vicinity of the probe in order to ablate the tissue; measuring a temperature in the vicinity of the probe; and deciding whether the probe is in contact with the tissue by comparing the measured temperature to a temperature threshold that varies in time depending on the time-varying power of the RF signal by setting the temperature threshold depending on a fourth root of the power of the RF signal and setting a proportion coefficient between the measured temperature and the fourth root of the power of the RF signal, based on a first coefficient that links the measured temperature and the fourth root of the power when the probe is in contact with the tissue, and a second coefficient that links the measured temperature and the fourth root of the power when the probe is not in contact with the tissue.