Patent ID: 6217574
Filing Date: 2001-04-17
Classification: A61B

Abstract:
A system for ablating tissue and estimating the maximum sub-surface temperature of said tissue comprising:a split tip electrode catheter comprising:an elongated catheter body having a proximal and distal end and at least one lumen extending therethrough;a catheter tip section at the distal end of the catheter body comprising a section of flexible tubing having proximal and distal ends and at least one lumen therethrough, the proximal end of the flexible tubing being fixedly attached to the distal end of the catheter body, said catheter tip section further comprising a split tip electrode which comprises at least two electrically isolated electrode members fixedly attached to the distal end of the flexible tubing, each electrode member comprising at least one irrigation passage;at least one indifferent electrode attachable to the exterior of a patient;means for generating a low level RF impedance current and for transmitting said impedance current to each electrode member of the split tip electrode;means for generating an RF ablation current and for transmitting said ablation current to each electrode member of the split tip electrode;means for electrically connecting each electrode member of the split tip electrode to the low level RF impedance current generating means and the RF ablation current generating means;means for receiving electrical signals indicative of the impedance between each electrode member and the at least one indifferent electrode during the transmission of RF ablation current and for separating such impedance indicating signals from other received signals; anda programmable signal processor, electrically connected to the RF impedance current generating means, the RF ablation current generating means, each of the electrode members of the split tip electrode, the at least one indifferent electrode and the signal receiving means, said signal processor being programmed to simultaneously activate the RF impedance current generating means and the RF ablation current generating means to transmit RF impedance current and RF ablation current and to estimate the maximum subsurface temperature based on the received electrical impedance-indicating signals.