Systems, apparatuses and methods for delivery of ablative energy to tissue

Abstract

A system includes a pulse waveform generator and an ablation device coupled to the pulse waveform generator. The ablation device includes at least one electrode configured for ablation pulse delivery to tissue during use. The pulse waveform generator is configured to deliver voltage pulses to the ablation device in the form of a pulsed waveform. A first level of a hierarchy of the pulsed waveform includes a first set of pulses, each pulse having a pulse time duration, with a first time interval separating successive pulses. A second level of the hierarchy of the pulsed waveform includes a plurality of first sets of pulses as a second set of pulses, a second time interval separating successive first sets of pulses, the second time interval being at least three times the duration of the first time interval.

1 . A system, comprising
 a pulse waveform generator; and   an ablation device coupled to the pulse waveform generator, the ablation device including at least one electrode configured for ablation pulse delivery to tissue during use,   wherein the pulse waveform generator is configured to deliver voltage pulses to the ablation device in the form of a pulsed waveform, wherein:   (a) a first level of a hierarchy of the pulsed waveform includes a first set of pulses, each pulse having a pulse time duration, a first time interval separating successive pulses;   (b) a second level of the hierarchy of the pulsed waveform includes a plurality of first sets of pulses as a second set of pulses, a second time interval separating successive first sets of pulses, the second time interval being at least three times the duration of the first time interval; and   (c) a third level of the hierarchy of the pulsed waveform includes a plurality of second sets of pulses as a third set of pulses, a third time interval separating successive second sets of pulses, the third time interval being at least thirty times the duration of the second level time interval.   
     
     
         2 . The system of  claim 1 , wherein the pulses of each first set of pulses include monophasic pulses with a voltage amplitude of at least 800 Volts, the pulse time duration of each monophasic pulse being in the range from about 1 microsecond to about 300 microseconds. 
     
     
         3 . The system of  claim 1 , wherein each second set of pulses includes at least 2 first sets of pulses and less than 40 first sets of pulses. 
     
     
         4 . The system of  claim 1 , where each third set of pulses includes at least 2 second sets of pulses and less than 30 second sets of pulses. 
     
     
         5 . The system of  claim 1 , the pulses of each first set of pulses including biphasic pulses each with a voltage amplitude of at least 800 Volts, the pulse time duration of each biphasic pulse being in the range from about 0.5 nanosecond to about 20 microseconds. 
     
     
         6 . The system of  claim 1 , where the second time interval is at least ten times the pulse time duration. 
     
     
         7 . The system of  claim 1 , where the ablation device includes an ablation catheter configured for epicardial placement. 
     
     
         8 . The system of  claim 1 , where the ablation device includes an ablation catheter configured for endocardial placement. 
     
     
         9 . A system, comprising
 a pulse waveform generator; and   an ablation device coupled to the pulse waveform generator, the ablation device including at least one electrode configured for ablation pulse delivery to tissue during use,   wherein the pulse waveform generator is configured to deliver voltage pulses to the ablation device in the form of a pulsed waveform, wherein:   (a) a first level of a hierarchy of the pulsed waveform includes a first set of pulses, each pulse having a pulse time duration, a first time interval separating successive pulses;   (b) a second level of the hierarchy of the pulsed waveform includes a plurality of first sets of pulses as a second set of pulses, a second time interval separating successive first sets of pulses, the second time interval being at least three times the duration of the first time interval; and   (c) a third level of the hierarchy of the pulsed waveform includes a plurality of second sets of pulses as a third set of pulses, a third time interval separating successive second sets of pulses, the third time interval being at least thirty times the duration of the second level time interval,   the pulse waveform generator configured to apply a plurality of the third set of pulses to the ablation device with a time delay of at most about 5 milliseconds between successive third sets of pulses.   
     
     
         10 . The system of  claim 9 , where the ablation device includes an ablation catheter configured for epicardial placement. 
     
     
         11 . The system of  claim 9 , where the ablation catheter includes at least four electrodes. 
     
     
         12 . The system of  claim 9 , wherein each second set of pulses includes at least 2 first sets of pulses and less than 40 first set of pulses. 
     
     
         13 . The system of  claim 9 , where each third set of pulses includes at least 2 second sets of pulses and less than 30 second set of pulses. 
     
     
         14 . The system of  claim 9 , the pulses of each first set of pulses having a voltage amplitude of at least 800 Volts. 
     
     
         15 . A system, comprising
 a pulse waveform generator;   an ablation device coupled to the pulse waveform generator, the ablation device including at least one electrode configured for ablation pulse delivery to tissue during use; and   a cardiac stimulator coupled to the pulse waveform generator, the cardiac stimulator configured for generating pacing signals for cardiac stimulation during use,   wherein the pulse waveform generator is configured to deliver voltage pulses to the ablation device in the form of a pulsed waveform, the pulsed waveform in synchrony with the pacing signals, wherein:   (a) a first level of a hierarchy of the pulsed waveform includes a first set of pulses, each pulse having a pulse time duration, a first time interval separating successive pulses;   (b) a second level of the hierarchy of the pulsed waveform includes a plurality of first sets of pulses as a second set of pulses, a second time interval separating successive first sets of pulses; and   (c) a third level of the hierarchy of the pulsed waveform includes a plurality of second sets of pulses as a third set of pulses, a third time interval separating successive second sets of pulses,   the pulse waveform generator configured to apply a plurality of the third sets of pulses to a predetermined number of electrode sets of the ablation device with a time delay between successive third sets of pulses,   and wherein the pulse waveform generator is configured to generate the pulsed waveform such that each of the first sets of pulses and each of the second sets of pulses, the predetermined number of electrode sets, the time delay, the pulse time duration, the first time interval, the second time interval, and the third time interval are jointly constrained by a Diophantine inequality.   
     
     
         16 . The system of  claim 15 , wherein the Diophantine inequality constraint is further characterized by a refractory time window. 
     
     
         17 . The system of  claim 15 , where a number of first sets of pulses and a number of second sets of pulses are pre-determined. 
     
     
         18 . The system of  claim 15 , the pulse waveform generator further configured to deliver the pulsed waveform spaced from the pacing signals by a time offset, the time offset being smaller than about 25 milliseconds. 
     
     
         19 . The system of  claim 15 , where the third time interval corresponds to a pacing period associated with the pacing signals. 
     
     
         20 . The system of  claim 15 , wherein the second time interval is at least three times the duration of the first time interval. 
     
     
         21 . The system of  claim 15 , wherein the third time interval is at least thirty times the duration of the second time interval. 
     
     
         22 . The system of  claim 15 , wherein the second time interval is at least ten times the duration of the pulse time duration. 
     
     
         23 . The system of  claim 15 , where the ablation device includes an ablation catheter configured for epicardial placement. 
     
     
         24 . The system of  claim 15 , where the ablation device includes an ablation catheter configured for endocardial placement. 
     
     
         25 . A system, comprising
 a pulse waveform generator including a user interface;   an ablation device coupled to the pulse waveform generator, the ablation device including a plurality of electrodes configured for ablation pulse delivery to tissue of a patient during use;   a cardiac stimulator coupled to the pulse waveform generator, the cardiac stimulator configured for generating pacing signals for cardiac stimulation of the patient during use,   wherein the pulse waveform generator is configured to deliver voltage pulses to the ablation device in the form of a pulsed voltage waveform having at least three levels of hierarchy,   wherein the pulse waveform generator is further configured to deliver the pulsed voltage waveform in synchrony with the pacing signals,   wherein the user interface of the pulse waveform generator is configured for receiving an indication of user confirmation of capture of the pacing signal by the patient's heart,   and wherein the pulse waveform generator is configured to deliver the pulsed voltage waveform upon receipt of the indication of user confirmation.   
     
     
         26 . The system of  claim 25 , wherein:
 (a) a first level of a hierarchy of the pulsed waveform includes a first set of pulses, each pulse having a pulse time duration, a first time interval separating successive pulses;   (b) a second level of the hierarchy of the pulsed waveform includes a plurality of first sets of pulses as a second set of pulses, a second time interval separating successive first sets of pulses; and   (c) a third level of the hierarchy of the pulsed waveform includes a plurality of second sets of pulses as a third set of pulses, a third time interval separating successive second sets of pulses,   wherein the pulse waveform generator is further configured to apply a plurality of third set of pulses to a predetermined number of electrode sets of the ablation device with a time delay between successive third set of pulses, and wherein each of the first sets of pulses and each of the second sets of pulses, the predetermined number of electrode sets, the time delay, the pulse time duration, the first time interval, the second time interval, and the third time interval are jointly constrained by a Diophantine inequality.   
     
     
         27 . The system of  claim 25 , the pulse waveform generator configured to deliver the pulsed waveform only after a pre-determined time interval after the indication of user confirmation. 
     
     
         28 . The system of  claim 27 , the user interface including a control input device, the pulse waveform generator configured to deliver the pulsed waveform upon user engagement of the control input device. 
     
     
         29 . The system of  claim 28 , the pulse waveform generator configured to stop pulsed waveform delivery within 20 milliseconds of user disengagement from the control input device. 
     
     
         30 - 31 . (canceled)