Apparatus and method for ablating tissue

• US 6,805,128 B1
• Filed: 07/12/2000
• Issued: 10/19/2004
• Est. Priority Date: 10/22/1996
• Status: Expired due to Fees

• Current Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Original Assignee: Epicor Medical, Inc. (Abbott Laboratories Incorporated)
• Inventors: Vaska, Matthias, Richman, Roxanne L., Anderson, Scott C., Gallup, David A., Podmore, Jonathan L., Pless, Benjamin, Ciciarelli, Timothy, Ulstad, Jack E. Jr., Crowe, John E.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US09/614,991
• Time in Patent Office: 1,560 Days
• Field of Search: 606/1, 606/27, 606/28, 606/167, 601/2, 607/97, 607/122, 600/439, 600/459, 600/461, 600/462, 600/465, 600/466, 128/898
• US Class Current: 128/898
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2018/00285 Balloons
• CPC Class Codes: A61B 2018/00291 using suction
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/002 Irrigation
• CPC Class Codes: A61B 2218/007 Aspiration
• CPC Class Codes: A61N 1/06 for high-frequency therapy
• CPC Class Codes: A61N 2007/0065 Concave transducers
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 2007/027 with multiple foci created simultaneously
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A control system alters one or more characteristics of an ablating element to ablate tissue. In one aspect, the control system delivers energy nearer to the surface of the tissue by changing the frequency or power. In another aspect, the ablating element delivers focused ultrasound which is focused in at least one dimension. The ablating device may also have a number of ablating elements with different characteristics such as focal length.

Claims

1. A method of ablating a cardiac tissue from an epicardial location, comprising the steps of:

providing an ablating device having a first ultrasound emitting element and a second ultrasound emitting element, each of the first and second ultrasound emitting elements emitting focused ultrasound having a focal length of 2-20 mm;

positioning the ablating device against an epicardial surface overlying a cardiac tissue structure to be ablated;

activating the first ultrasound emitting element at a first frequency to produce focused ultrasound having the focal length of 2-20 mm, the focused ultrasound ablating a cardiac tissue structure; and

activating the second ultrasound emitting element at a second frequency, different from the first frequency, to produce focused ultrasound having the focal length of 2-20 mm to ablate the cardiac tissue structure.

2. The method of claim 1, further comprising the step of:

moving the ablating device so that the activating steps are carried out to ablate the same tissue.

3. The method of claim 1, wherein:

the activating steps are carried out to ablate different cardiac tissue.

4. The method of claim 1, further comprising:

characterizing a portion of cardiac tissue; and

selecting at least one of the first and second ultrasound emitting elements to ablate the portion of cardiac tissue based on the characterizing step.

5. A method of ablating a cardiac tissue from an epicardial location, comprising the steps of:

providing an ablating device having a body with a first ultrasound emitting element and a second ultrasound emitting element, the first and second ultrasound emitting elements both producing focused ultrasound, the first and second ultrasound emitting elements producing focused ultrasound having different focal lengths relative to the body;

positioning the ablating device at an epicardial location;

activating the first ultrasound emitting element to ablate cardiac tissue; and

activating the second ultrasound emitting element.

6. The method of claim 5, wherein:

the providing step is carried out with the first and second ultrasound emitting elements being movable along the body; and

the positioning step is carried out by positioning the body along a desired ablation path.

7. The method of claim 6, further comprising the step of:

moving the first and second ultrasound emitting elements along the body.

8. The method of claim 6, further comprising the step of:

positioning the body at a selected location on the epicardial surface to create an elongate lesion using the first and second ultrasound emitting elements; and

moving the first and second ultrasound emitting element after the positioning step.