US 2014/0194869 A1 · METHOD AND APPARATUS FOR CONTROLLING LESION SIZE IN CATHETER-BASED ABLATION

Abstract

A method and apparatus that utilizes a force-time integral for real time estimation of lesion size in catheter-based ablation systems. The apparatus measures the force exerted by a contact ablation probe on a target tissue and integrates the force over an energization time of the ablation probe. The force-time integral can be calculated and utilized to provide an estimated lesion size (depth, volume and/or area) in real time. The force-time integral may also account for variations in the power delivered to the target tissue in real time to provide an improved estimation of the lesion size. In one embodiment, the force metric can be used as feedback to establish a desired power level delivered to the probe to prevent steam popping.

Claims33

Dependent claims

A system for ablating a target tissue during a medical procedure, the system comprising:

an elongate flexible catheter adapted to be introduced into a patient during said medical procedure, said catheter including a distal portion;
an ablation head disposed at said distal portion of said catheter, said ablation head adapted to contact with said target tissue during said medical procedure;
a force sensor operatively coupled with said ablation head for measurement of a contact force exerted on said ablation head, said force sensor configured to output a signal in response to said contact force;
a power source operatively coupled with said ablation head for energization of said ablation head;
and
a control system configured to receive said signal from said force sensor and to produce a sequence of contact force values acquired over a time period of energization based on said signal output by said force sensor for calculation of a force-time integral that is utilized by said control system to control ablation of said target tissue.

3 more elements

A system for delivering energy to a target tissue during a medical procedure, the system comprising:

an elongate flexible catheter adapted to be introduced into a patient during said medical procedure, said catheter including a distal portion;
an ablation head disposed at said distal portion of said catheter and arranged to contact said target tissue during said medical procedure;
a force sensor operatively coupled with said ablation head for detection of a contact force exerted on said ablation head, said force sensor adapted produce an output that correlates with said contact force;
a power source operatively coupled with said ablation head for energization of said ablation head;
and
a control system including a central processor and being operatively coupled to said force sensor and said power source, said central processor having access to a storage medium that contains programming instructions to be carried out by the central processor, said programming instructions comprising:
measuring a sequence of contact forces with said force sensor while said ablation head is in contact with said target tissue, said sequence of contact forces being in reaction to said contact;
energizing said ablation head for a period of time while said sequence of contact forces is being measured;
and
determining a force-time integral based on said sequence of contact forces that were measured with said force sensor over said period of time of energizing said ablation head.

7 more elements

Dependencies are inferred from the claim text.

Method and apparatus for controlling lesion size in catheter-based ablation

Life of this patent

Method and apparatus for controlling lesion size in catheter-based ablation

Life of this patent

Abstract

Claims33