Medical system for delivering optimal cryogenic dose based on time to effect (tte)

Abstract

A system and method for determining an optimal dose of cryotherapy for isolation of a target tissue region based on time to effect (TTE). The system may generally include a treatment device, a sensing device, and a processor programmed to calculate an optimal dose of cryotherapy (in seconds) based on the TTE. TTE may be based on electrical signals received by the processor from the sensing device. The processor may further be programmed to automatically terminate the cryoablation procedure when the optimal dose of cryotherapy has elapsed. The optimal dose of cryotherapy may be the time (in seconds) it takes to achieve isolation, which may be the time it takes for the tissue region to reach approximately -20°C.

Description

technical field [0001] The present invention relates to a system and method for determining an optimal dose of cryotherapy for isolation of a target tissue region based on time to effect (TTE). Background technique [0002] Cryotherapy, especially cryoablation, is often used to treat various cardiac arrhythmias, including atrial fibrillation. Many arrhythmias are caused by or involve abnormal electrical currents being conducted through the tissue of the heart. During cryoablation, tissue is cooled through a cryotherapy catheter until abnormal electrical conduction is eliminated or otherwise deemed to be improved. For example, some abnormal currents may originate in one or more pulmonary veins. In such cases, the pulmonary ostia and / or pulmonary sinuses may be cooled until the pulmonary vein(s) are isolated from the left atrium or other cardiac tissue. [0003] Time to effect (TTE) can be defined as the time it takes for a region of cardiac tissue to cease conducting elect...

AI Technical Summary

Problems solved by technology

[0004] It may be difficult to direct or control the depth of cryoablation when addressing specific regions of tissue

For example, reductions in tissue temperature may not be contained within the exact zone or depth desired to be treated using currently known methods, and this often requires that lesion formation and / or tissue temperature must be carefully monitored in real time (which may be difficult and imprecise), and / or lesion formation must be assessed after cryoablation procedures, which can lead to unintentional damage if not monitored during the procedure

If the lesion extends too far or too deep beyond the targeted treatment area, it can lead to collateral damage to non-targeted tissues

In turn, if the treatment is not delivered for enough time or at a sufficient depth of tissue, the procedure may fail to correct abnormal electrical conduction

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