Apparatus and method for ablating tissue

• US 6,805,129 B1
• Filed: 10/27/2000
• 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: Gallup, David A., Podmore, Jonathan L., Pless, Benjamin, Ciciarelli, Timothy, Ulstad, Jack E. Jr., Vaska, Matthias, Richman, Roxanne L., Anderson, Scott C., Crowe, John E.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US09/698,357
• Time in Patent Office: 1,453 Days
• Field of Search: 606/27, 606/28, 606/41, 606/169, 604/22, 600/437, 600/439, 600/459, 600/461, 600/452, 600/465, 600/466, 600/462, 601/2, 601/3, 128/898
• US Class Current: 128/898
• CPC Class Codes: A61B 17/22012 in direct contact with, or very close to, the obstruction or concrement for removing obstructions in blood vessels by laser A61B18/245
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 18/00 Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body eye surgery A61F9/007; ear surgery A61F11/00
• 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 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• 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 2017/00243 cardiac
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/00252 for by-pass connections, i.e. connections from heart chamber to blood vessel or from blood vessel to blood vessel
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2017/3419 Sealing means between cannula and body
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00232 having an irregular shape
• CPC Class Codes: A61B 2018/00261 arranged in a line
• 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 2018/00363 : Epicardium
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00577 : Ablation
• CPC Class Codes: A61B 2018/00654 : with individual control of each of a plurality of energy emitting elements
• CPC Class Codes: A61B 2018/00797 : measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00839 : Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/142 : at least partly surrounding the target, e.g. concave, curved or in the form of a cave
• 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 2090/3614 : using optical fibre
• CPC Class Codes: A61B 2090/3782 : transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 2090/395 : with marking agent for marking skin or other tissue
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration
• CPC Class Codes: A61B 34/20 : Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/287 : Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61N 1/06 : for high-frequency therapy
• CPC Class Codes: A61N 1/3629 : in combination with non-electric 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 cardiac tissue from an epicardial location, comprising the steps of:

providing an ablating device having an ultrasound emitting element;

positioning the ablating device in contact with a location outside the patient'"'"'s heart overlying a cardiac tissue structure to be ablated;

activating the ultrasonic emitting element at a first frequency to produce focused ultrasound energy which is directed at the tissue structure, the ultrasound emitting element being activated for a number of discrete time periods at the first frequency; and

activating the ultrasound emitting element for a second period of time at a second frequency which is different than the first frequency, the second period of time occurring after the number of discrete time periods.

2. The method of claim 1, wherein:

the activating steps are carried out with the first period of time being shorter than the second period of time.

3. The method of claim 1, wherein:

the activating steps are carried out with the first period of time being less than 1 second.

4. The method of claim 1, wherein:

the activating step is carried out by activating the ultrasound emitting element at a third frequency different than the first and second for a third period of time, the third period of time occurring after the number of discrete time periods and the second period of time.

5. The method of claim 1, wherein:

the activating stop is carried out with the first frequency being about 2-7 MHz and the second frequency being from 2-14 MHz.

6. The method of claim 1, wherein:

the providing step is carried out with the ablating device producing focused energy having a focal length of 2 to 20 mm.

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

approximating a temperature using the ultrasound emitting element.

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

assessing the adequacy of contact between tissue and the device.

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

measuring a blood flow velocity with the ultrasound emitting element.

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

determining a tissue layer thickness using the ultrasound emitting element.

11. The method of claim 10, wherein:

the determining step is carried out with the tissue layer being a tissue layer between a near surface and a far surface.

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

moving the ultrasound beam after the activating step.

13. The method of claim 12, wherein:

the moving step is carried out with the ultrasound beam being rotated.

14. The method of claim 12, wherein:

the moving step is carried out by moving the ultrasound emitting element.

15. The method of claim 12, wherein:

the moving step is carried out with the ultrasound emitting element being tilted.