US 12,256,982 B2
Measuring thickness of cardiac wall tissue during ablation
Assaf Govari, Haifa (IL); and Andres Claudio Altmann, Haifa (IL)
Assigned to Biosense Webster (Israel) Ltd., Yokneam (IL)
Filed by BIOSENSE WEBSTER (ISRAEL) LTD., Yokneam (IL)
Filed on Mar. 19, 2020, as Appl. No. 16/823,527.
Prior Publication US 2021/0290301 A1, Sep. 23, 2021
Int. Cl. A61B 18/14 (2006.01); A61B 18/00 (2006.01); A61B 90/00 (2016.01)
CPC A61B 18/1492 (2013.01) [A61B 2018/00351 (2013.01); A61B 2018/00577 (2013.01); A61B 2018/00613 (2013.01); A61B 2018/00839 (2013.01); A61B 2090/062 (2016.02)] 9 Claims
OG exemplary drawing
 
1. A method for iteratively estimating a thickness of cardiac tissue undergoing ablation, the method comprising the steps of:
prespecifying a planned depth for ablation and a prespecified incremental value, wherein the prespecified incremental value is less than the planned depth for ablation;
applying a sequence of ablation pulses to a region of the cardiac tissue, so as to create a lesion; and
for a given ablation pulse in the sequence:
estimating a current incremental depth added to the lesion due to the given ablation pulse;
estimating a cumulative depth of the lesion based on a prior cumulative depth prior to the given pulse, and on the current incremental depth;
assessing an amplitude of an electrogram signal at the region of the cardiac tissue undergoing ablation after applying the given ablation pulse, and, if the amplitude exceeds a predefined threshold, setting an estimate of the thickness to be at least the last estimated cumulative depth; and
setting, for a next ablation pulse in the sequence of ablation pulses, an additional time duration for the next ablation where the additional time duration is configured to add a next incremental lesion depth, wherein the next incremental lesion depth is estimated to change a next incremental depth caused by the next ablation pulse to the region of the cardiac tissue to be smaller than the prespecified incremental value;
wherein applying the ablation pulses comprises applying irreversible electroporation (IRE) pulses,
wherein the amplitude of the electrogram signal of the arrhythmogenic signal at the region of the cardiac tissue undergoing ablation decreases after each iteration;
wherein assessing the amplitude of an electrogram signal comprises measuring the amplitude during an intermission between the ablation pulses, and
wherein the steps are performed automatically under a processor control.