Dielectric-coated ablation electrode having a non-coated window with thermal sensors

A catheter for applying energy to biological tissue having biological fluid flowing thereby, said catheter comprising:

• a shaft having a distal-end region defining a tissue-contacting surface and a fluid-contacting surface;
• a plurality of band electrodes positioned at the distal-end region of the shaft;
• a thermally conductive and non-electrically conductive surface covering comprising a dielectric material having a thickness in the range of approximately 0.001 to 0.05 millimeters that covers a portion of each of the band electrodes substantially coincident with the fluid-contacting surface, each band electrode thereby having at least one masked portion substantially coincident with the fluid-contacting surface and at least one non-masked portion substantially coincident with the tissue-contacting surface;
• and
• a plurality of thermal sensors, at least one thermal sensor located in a non-masked portion of each of the band electrodes.

An RF ablation system for applying energy to biological tissue having biological fluid flowing thereby, said system comprising:

• a catheter having:
• a shaft having a distal-end region defining a tissue-contacting surface and a fluid-contacting surface;
• at least one electrode positioned at the distal-end region of the shaft;
• a thermally conductive and non-electrically conductive surface covering comprising a dielectric material having a thickness in the range of approximately 0.001 to 0.05 millimeters that covers a portion of the electrode substantially coincident with the fluid-contacting surface, the electrode thereby having at least one masked portion substantially coincident with the fluid-contacting surface and at least one non-masked portion substantially coincident with the tissue-contacting surface;
• and
• at least one thermal sensor located in a non-masked portion of the electrode and adapted to provide temperature signals indicative of the temperature at the electrode;
• a power generator adapted to provide power to the at least one electrode;
• and
• a processor adapted to receive the temperature signals from the at least one thermal sensor and control the provision of power by the power generator based on the signals.