Ablation methods and medical apparatus using same

A method for use in ablating tissue, comprising:

• providing a catheter comprising an ablation electrode;
• ablating tissue using the ablation electrode, wherein the ablation electrode directs electromagnetic energy to the tissue;
• detecting acoustical energy and providing a transducer signal representative of the detected acoustical energy during ablation of tissue;
• removing at least a cardiac generated acoustical energy component from the transducer signal;
• and
• controlling the electromagnetic energy directed to the tissue based on the transducer signal having the at least a cardiac generated acoustical energy component removed therefrom.

A method for use in ablating cardiac tissue, comprising:

• providing a catheter comprising an ablation electrode and a piezoelectric transducer element operable for use in detecting acoustical energy;
• ablating tissue using the ablation electrode, wherein the ablation electrode directs electromagnetic energy to the tissue;
• detecting acoustical energy using the piezoelectric transducer element for detection of at least one popping sound;
• if at least one popping sound is detected, reducing the electromagnetic energy directed to the tissue.

A method for use in ablating tissue, comprising;

• providing a catheter comprising an ablation electrode and a piezoelectric transducer element;
• ablating cardiac tissue using the ablation electrode, wherein the ablation electrode directs electromagnetic energy to the cardiac tissue;
• detecting acoustical energy during ablation of cardiac tissue using the piezoelectric transducer element and providing a transducer signal representative thereof, wherein the transducer signal is further representative of an ablation temperature proximate tissue being ablated;
• and
• controlling the electromagnetic energy directed to the tissue based on the transducer signal.

A method for use in ablating tissue, comprising:

• providing a catheter comprising an ablation electrode;
• ablating tissue using the ablation electrode, wherein the ablation electrode directs electromagnetic energy to the tissue;
• detecting acoustical energy and providing a transducer signal representative of the detected acoustical energy;
• measuring a sound intensity of the detected acoustical energy;
• comparing the measured sound intensity to a sound intensity threshold;
• if the measured sound intensity is greater than the sound intensity threshold, then comparing the transducer signal to at least a portion of an ECG waveform;
• and
• reducing the electromagnetic energy directed to the tissue if the transducer signal and the at least a portion of an ECG waveform are asynchronous.

A method for use in ablating cardiac tissue, comprising:

• providing a catheter comprising an ablation electrode and a tensiometric element;
• ablating tissue using the ablation electrode, wherein the ablation electrode directs electromagnetic energy to the cardiac tissue;
• detecting a plurality of cardiac contractions using the tensiometric element and providing a tensiometric signal representative of the plurality of cardiac contractions;
• detecting acoustical energy and providing a transducer signal representative of the detected acoustical energy;
• comparing the tensiometric signal to the transducer signal;
• and
• controlling the electromagnetic energy directed to the cardiac tissue based on the compared tensiometric signal and transducer signal.