Systems and methods for treating tissue of a passageway within a body

• US 9,770,293 B2
• Filed: 05/16/2013
• Issued: 09/26/2017
• Est. Priority Date: 06/04/2012
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Dresher, Russell P.
• Primary Examiner(s): Giuliani, Thomas
• Application Number:
  US13/895,771
• Publication Number:
  US 20130324995A1
• Time in Patent Office: 1,594 Days
• Field of Search: 606 33, 606 34, 606 38, 606 42
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• 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 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00267 having a basket shaped structure
• CPC Class Codes: A61B 2018/00541 Lung or bronchi
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00672 lower
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00708 switching the power on or off
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00785 Reflected power
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure

Abstract

The present disclosure is directed to a method for treating tissue in a passageway within a body. The method may include positioning a medical device adjacent a treatment site in the passageway. The medical device may include an elongate member having a proximal end and a distal end, and an energy emitting portion positioned adjacent the distal end. The method may further include supplying an amount of energy from an energy source to the energy emitting portion. A first portion of the amount of the energy may be transmitted through the energy emitting portion to the tissue and a second portion of the amount of energy may be reflected from the energy emitting portion. The method may further include monitoring a signal corresponding to one of the first portion of the amount of energy and the second portion of the amount of energy.

Claims

1. A method for treating tissue in a passageway within a body, the method comprising:

positioning a medical device adjacent a treatment site in the passageway, the medical device including;

a shaft having a proximal end and a distal end; and

an energy emitting portion at or adjacent the distal end;

supplying an amount of non-therapeutic energy from an energy source to the energy emitting portion;

monitoring a first signal corresponding to an amount of the non-therapeutic energy being reflected back towards the proximal end of the shaft;

when the amount of the non-therapeutic energy reflected back towards the proximal end of the shaft exceeds a contact threshold, supplying an amount of therapeutic energy from the energy source to the energy emitting portion to treat tissue at the treatment site, a first portion of the amount of therapeutic energy being transmitted through the energy emitting portion to the tissue and a second portion of the amount of therapeutic energy being reflected back towards the proximal end of the shaft; and

monitoring a second signal corresponding to one of the first portion of the amount of therapeutic energy and the second portion of the amount of therapeutic energy.

2. The method of claim 1, wherein the second signal corresponds to the first portion of the amount of therapeutic energy, the second signal has a power, and wherein the power decreases during delivery of therapeutic energy to the tissue.

3. The method of claim 1, wherein the second signal corresponds to the second portion of the amount of therapeutic energy, the second signal has a power, and wherein the power increases during delivery of therapeutic energy to the tissue.

4. The method of claim 1, wherein the energy source is an RF generator.

5. The method of claim 1, further comprising:

determining a state of treatment based on the second signal.

6. The method of claim 5, wherein the monitoring of the first and second signals is performed by a bi-directional coupler.

7. The method of claim 5, wherein the second signal has a power, and wherein the method further includes determining if the power passes a power threshold.

8. The method of claim 7, wherein the method further includes terminating the supply of therapeutic energy to the energy emitting portion when the power exceeds the power threshold.

9. The method of claim 7, wherein the power threshold corresponds to a power level for ablating tissue.

10. The method of claim 5, wherein the second signal corresponds to the first portion of the amount of therapeutic energy, wherein the second signal corresponding to the reflected therapeutic energy has a power, and wherein the power is proportional to an impedance of the tissue, and the impedance of the tissue decreases during delivery of therapeutic energy to the tissue.

11. The method of claim 5, wherein the energy source is an RF generator.

12. The method of claim 5, wherein the second signal corresponds to the first portion of the amount of therapeutic energy, wherein the second signal corresponding to the reflected therapeutic energy has a power, and wherein the power is a function of an amount of tissue contact with the energy emitting portion.

13. The method of claim 5, further including analyzing the second signal to determine a rate of change in the signal, and determining an amount of contact between the tissue and the energy emitting portion based on the rate of change.

14. The method of claim 5, wherein the second signal corresponds to the first portion of the amount of therapeutic energy, and the method further includes expanding the energy emitting portion from a collapsed configuration to an expanded configuration to contact tissue, wherein the second signal corresponding to the reflected therapeutic energy has a power, and wherein the power is configured to change as the energy emitting portion contacts tissue.

15. A method for treating tissue in a passageway within a body, the method comprising:

positioning a medical device adjacent a treatment site in the passageway, the medical device including;

a shaft having a proximal end and a distal end; and

an energy emitting portion at or adjacent the distal end;

supplying an amount of non-therapeutic energy from an energy source to the energy emitting portion;

monitoring a signal corresponding to an amount of the non-therapeutic energy being reflected back towards the proximal end of the shaft; and

determining whether the energy emitting portion is in contact with tissue by comparing the amount of the non-therapeutic energy reflected back towards the proximal end of the shaft with a threshold; and

supplying an amount of therapeutic energy from the energy source to the energy emitting portion to treat the tissue only when the amount of the non-therapeutic energy reflected back towards the proximal end of the shaft exceeds the threshold and indicates contact with tissue.

16. The method of claim 15, wherein the non-therapeutic energy has a power from 1-3 dBm.

17. A method for treating tissue in a passageway within a body, the method comprising:

positioning a medical device adjacent a treatment site in the passageway, wherein the passageway is a lung passageway, the medical device including;

a shaft having a proximal end and a distal end; and

an expandable basket at or adjacent the distal end of the shaft, wherein the expandable basket is movable between a retracted configuration and one or more expanded configurations and includes a plurality of circumferentially spaced legs, wherein each of the legs includes an exposed energy emitting portion defined at first and second ends by non-conductive material;

supplying an amount of non-therapeutic RF energy from an energy source to one or more of the energy emitting portions, wherein the non-therapeutic energy has a power from 1-3 dBm;

monitoring a signal corresponding to an amount of the non-therapeutic RF energy being reflected back towards the proximal end of the shaft from the one or more of the energy emitting portions;

comparing the amount of the non-therapeutic RF energy reflected back towards the proximal end of the shaft from the one or more of the energy emitting portions to a first threshold;

when the amount of the non-therapeutic RF energy reflected back towards the proximal end of the shaft from the one or more energy emitting portions exceeds the first threshold, supplying an amount of therapeutic RF energy from the energy source to the one or more energy emitting portions to treat tissue at the treatment site, wherein the therapeutic RF energy causes the one or more energy emitting portions to reach a temperature from about 60 to 80 degrees Celsius; and

when the amount of non-therapeutic RF energy reflected back towards the proximal end of the shaft from the one or more energy emitting portions is less than the first threshold, withholding the supply of therapeutic RF energy to the one or more energy emitting portions.

18. The method of claim 17, wherein visualization of the basket is obstructed during both supplying steps.